CN116056675A - Pants-type absorbent article - Google Patents

Pants-type absorbent article Download PDF

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Publication number
CN116056675A
CN116056675A CN202180061748.0A CN202180061748A CN116056675A CN 116056675 A CN116056675 A CN 116056675A CN 202180061748 A CN202180061748 A CN 202180061748A CN 116056675 A CN116056675 A CN 116056675A
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CN
China
Prior art keywords
sheet
absorbent article
composite
stretchable
type absorbent
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Pending
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CN202180061748.0A
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Chinese (zh)
Inventor
坂仓嵩
犹守沙耶香
川口宏子
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Kao Corp
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Kao Corp
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Publication date
Application filed by Kao Corp filed Critical Kao Corp
Priority claimed from JP2021146050A external-priority patent/JP7037693B1/en
Publication of CN116056675A publication Critical patent/CN116056675A/en
Pending legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/45—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape
    • A61F13/49—Absorbent articles specially adapted to be worn around the waist, e.g. diapers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/51—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers

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  • Health & Medical Sciences (AREA)
  • Epidemiology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

In a composite stretchable portion (10E) in a natural state, an inner sheet (12) has a gather structure composed of a plurality of concave strip portions (120) having a joint portion (13) at the bottom and extending in the longitudinal direction (X), and convex strip portions (121) located between the concave strip portions (120) and having a curved portion (12P) of the inner sheet (12) as the top, and an outer sheet (11) has a plurality of curved portions (11P) in a region overlapping with 1 convex strip portion (121) of the inner sheet (12) in a plan view. At least one of the abdomen side part (A) and the back side part (R) is provided with an outer body folding-back part (14), and the outer body folding-back part (14) comprises a part of the composite expansion part (10E) folded back in a manner that the inner layer sheet (12) is folded back inside.

Description

Pants-type absorbent article
Technical Field
The present invention relates to a pants-type absorbent article such as a pants-type disposable diaper.
Background
A pants-type disposable diaper, which is one type of pants-type absorbent article, typically has the following structure: an absorbent body including an absorbent body, and an outer body disposed on a non-skin-facing side of the absorbent body, wherein a pair of side joint portions, a waist opening portion, and a pair of leg opening portions are formed in such a manner that both side edge portions of each of a front body portion and a rear body portion in a longitudinal direction are joined to each other. In the pants-type disposable diaper having such a structure, a plurality of elastic members are disposed at intervals in the longitudinal direction in the outer body between the waist opening and the leg opening so as to be stretchable and fixed in the lateral direction in order to improve the fit to the body of the wearer. The longitudinal direction is a direction corresponding to the front-rear direction of the wearer, and the transverse direction is a direction orthogonal to the longitudinal direction.
Patent document 1 describes that as an outer covering for a pants-type disposable diaper, an outer covering having an outer sheet on the outer surface side of the diaper, an inner sheet on the inner surface side of the diaper, and a plurality of elastic members arranged between the two sheets is used, and wrinkles are formed by a composite stretch unit. In the composite stretch unit, the outer sheet and the inner sheet are joined by a large number of joining portions dispersed in both the stretch direction of the composite stretch unit (the transverse direction of the diaper) and the orthogonal direction thereof (the longitudinal direction of the diaper), the elastic members are disposed so as not to pass through the joining portions, and both ends in the longitudinal direction of the elastic members are fixed between the two sheets, and the two sheets form a plurality of wrinkles extending continuously over the plurality of elastic members, respectively, and the sizes of the wrinkles are different in the outer sheet and the inner sheet. According to the pants-type disposable diaper described in patent document 1, the composite stretchable portion is excellent in breathability and flexibility, and has different cushioning properties on the front and back surfaces of the outer body.
Patent document 2 describes that an outer case having a stretchable composite portion including a stretchable sheet and a non-stretchable sheet joined to the surface facing the stretchable sheet is used as an outer case of a pants-type disposable diaper. In the stretchable composite portion in a natural state, a large number of first raised lines are formed on the surface on the non-stretchable sheet side, and a large number of second raised lines lower than the first raised lines are formed on the surface on the stretchable sheet side, and the first raised lines are disposed so as to be capable of abutting against the skin of the wearer. The pants-type disposable diaper described in patent document 2 provides cushioning properties by the raised lines on the side of the surface that contacts the skin of the wearer, and the raised lines are arranged on the outer surface at a lower level than the raised lines, so that the feel of the appearance is reduced, and the appearance and feel similar to those of underwear can be achieved.
Patent document 3 describes an outer cover in the vicinity of a waist opening of a pants-type disposable diaper, wherein, in a natural state, each of an inner sheet surface and an outer sheet surface has a plurality of wrinkles spaced apart in the circumferential direction of the waist opening, and the interval between the wrinkles of the inner sheet surface is smaller than the interval between the wrinkles of the outer sheet surface. The pants-type disposable diaper described in patent document 2 can obtain good cushioning properties by the wrinkles of the inner sheet on the side of the surface that contacts the skin of the wearer, and can reduce the sense of thickness in appearance by the wrinkles of the outer sheet at relatively large intervals on the outer surface side of the diaper, thereby realizing an underwear-like appearance.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2009-297096
Patent document 2: japanese patent application laid-open No. 2010-284228
Patent document 3: japanese patent application laid-open No. 2010-284229
Disclosure of Invention
The present invention relates to a pants-type absorbent article having a longitudinal direction extending from the abdomen side of a wearer to the back side via a crotch portion and a transverse direction orthogonal to the longitudinal direction, the pants-type absorbent article being divided into a crotch portion disposed in the crotch portion of the wearer, an abdomen side portion disposed closer to the abdomen side of the wearer than the crotch portion, and a back side portion disposed closer to the back side of the wearer than the crotch portion, the pants-type absorbent article comprising an absorbent main body including an absorber, and an outer body disposed on a non-skin-facing side of the absorbent main body,
The side portions and the back portion are joined to each other at both side edges of the outer body along the longitudinal direction, and a waist opening and a pair of leg openings are formed.
In one embodiment of the pants-type absorbent article according to the present invention, the outer body preferably includes an outer sheet disposed at a relatively distant position from the absorbent body and an inner sheet disposed at a relatively close position to the absorbent body.
In one embodiment of the pants-type absorbent article according to the present invention, it is preferable that at least a part of the outer cover is a composite stretchable portion having stretchability in the lateral direction, and the outer layer sheet and the inner layer sheet are joined at the composite stretchable portion by a plurality of joining portions arranged at intervals in the lateral direction.
In one embodiment of the pants-type absorbent article according to the present invention, it is preferable that the inner sheet has a gather structure including a plurality of concave portions extending in the longitudinal direction and having the joint portion at the bottom, and convex portions located between the concave portions and having the curved portions of the inner sheet as the tops, at the composite stretch portions in a natural state, and the outer sheet has a plurality of curved portions in a region overlapping with 1 of the convex portions of the inner sheet in a plan view.
In one embodiment of the pants-type absorbent article according to the present invention, it is preferable that at least one of the abdomen-side portion and the back-side portion is provided with an outer-cover folded-back portion including a portion where the composite stretchable portion is folded back so that the inner sheet is inside.
Other features, effects and embodiments of the present invention are described below.
Drawings
Fig. 1 is a perspective view schematically showing a pants-type disposable diaper according to an embodiment of the pants-type absorbent article of the present invention.
Fig. 2 is a developed plan view of the diaper shown in fig. 1, partially cut away on the skin-facing surface (inner surface) side in the developed and extended state, and schematically shown.
Fig. 3 is an exploded perspective view of the diaper shown in fig. 1, shown exploded and schematically.
Fig. 4 is a cross-sectional view schematically showing a section of the line I-I of fig. 2.
Fig. 5 is a longitudinal sectional view schematically showing a section of the line II-II of fig. 2.
Fig. 6 is a partially cut-away perspective view schematically showing an example of a stretchable sheet that can be used as the outer sheet of the diaper shown in fig. 1.
Fig. 7 is a cross-sectional view schematically showing a section of line III-III of fig. 5, and is a cross-sectional view of a folded-back portion of the outer body in a natural state of the diaper shown in fig. 1.
Fig. 8 is a schematic perspective view of the folded-back portion of the exterior body in the natural state shown in fig. 7.
Fig. 9 is a schematic cross-sectional view of a composite stretch unit constituting the folded-back portion of the exterior body shown in fig. 7.
Fig. 10 is a view corresponding to fig. 7 of another embodiment of the package folding-back portion of the present invention.
Detailed Description
As a person who is the main wearer of the pants-type disposable diaper, a low-month-old infant can be exemplified. In general, since a low-month-old infant is put on a diaper for a long period of time while sleeping, the waist region or the like in the outer body of the diaper strongly presses the skin of the wearer, a pressing mark is easily formed on the skin, and there is a possibility that a burden is placed on the skin. In addition, if an infant wearing the diaper is in a sleeping position for a long period of time, the air permeability of the portion of the diaper that strongly presses the skin of the wearer may be reduced, and there is a possibility that a problem such as stuffy feeling may occur. The conventional pants-type absorbent article has room for improvement in terms of cushioning properties, breathability, and the like of the outer case.
Accordingly, the present invention relates to a pants-type absorbent article which has an outer covering excellent in cushioning properties and breathability, and which is less likely to cause pressure marks on the skin of a wearer who is asleep and is less likely to be stuffy.
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are denoted by the same or similar reference numerals. The drawings are basically schematic, and the ratio of the dimensions and the like may be different from the ratio of the actual dimensions.
The pants-type absorbent article of the present invention has a longitudinal direction (direction indicated by "X") corresponding to the front-back direction of the wearer, that is, the direction extending from the abdomen side to the back side through the crotch, and a transverse direction (direction indicated by "Y") orthogonal to the longitudinal direction.
In the following description, unless otherwise specified, the longitudinal direction is the longitudinal direction of the absorbent article or the direction along the longitudinal direction of its constituent members (e.g., absorbent body), and the transverse direction is the transverse direction of the absorbent article or the direction along the transverse direction of its constituent members.
The pants-type absorbent article of the present invention is divided into: a crotch portion (a portion denoted by "B") disposed in the crotch of the wearer; an abdomen-side portion (a portion denoted by "a") disposed closer to the abdomen of the wearer than the crotch portion; and a back side portion (portion denoted by reference character "C") disposed closer to the back side of the wearer than the crotch portion, and having an absorbent main body (member denoted by reference character "2") including an absorber (member denoted by reference character "5"); and an outer body (a member denoted by reference numeral 10) disposed on the non-skin-facing side of the absorbent main body.
In the present specification, the "skin-facing surface" refers to a surface of the absorbent article or a component thereof (for example, an outer body) that faces the skin side of the wearer when the absorbent article is worn, that is, a surface that is relatively close to the skin of the wearer, and the "non-skin-facing surface" refers to a surface of the absorbent article or a component thereof that faces the opposite side of the skin side when the absorbent article is worn, that is, a surface that is relatively far from the skin of the wearer. The term "when worn" as used herein refers to a state in which the absorbent article is maintained in a generally proper wearing position, that is, in a correct wearing position.
In the pants-type absorbent article of the present invention, both side edges of the outer body of each of the abdomen-side portion and the back-side portion in the longitudinal direction are joined to each other, and a waist opening (a portion denoted by "WH") and a pair of leg openings (a portion denoted by "LH") are formed.
Fig. 1 to 5 show a pants-type disposable diaper 1, which is one embodiment of the pants-type absorbent article of the present invention, and the diaper 1 has the above-described structure.
In the present embodiment, the side edges 10S of the outer body 10 of each of the abdomen portion a and the back portion C along the longitudinal direction X are joined to each other, and a pair of side joining portions S are formed. The joining method of the outer body 10 to each other at the side joining portion S is not particularly limited, and examples thereof include welding, adhesive, sewing, and the like, and the application of the pants-type absorbent article can be arbitrarily selected depending on the material of the outer body 10, and the like. Typically, the joining method of the outer body 10 to each other in the side joining portion S of the pants-type disposable diaper is welding and/or an adhesive, and the joining method of the outer body 10 to each other in the side joining portion S of the pants-type physiological pants is stitching. The side seal S of the present embodiment is a so-called side seal in which both side edges 10S of the outer body 10 are bonded to each other by welding, and protrudes outward from the peripheral portion as shown in fig. 1.
The diaper 1 is divided into a front body F and a rear body R. As shown in fig. 2, the front body F is a portion that covers the abdomen side (front side) of the wearer's body when worn, and the rear body R is a portion that covers the back side (rear side) of the wearer's body, with respect to a longitudinal center line CLx that bisects the diaper 1 in the developed and extended state in the longitudinal direction X and extends in the lateral direction Y. The term "developed and extended state" as used herein refers to a state in which the diaper 1 is cut into a developed state at the side joining portions S, and the developed state of the diaper 1 is expanded to a state in which the elastic members of each portion are extended to have a designed size (the same size as when the diaper is expanded into a planar shape in a state in which the influence of all the elastic members is removed).
The ventral portion a is a part of the front body F, and the dorsal portion C is a part of the rear body R. The crotch portion B extends in the longitudinal direction X across the longitudinal center line CLx and extends from the front body F to the rear body R. The ventral portion a and the dorsal portion C are each typically a portion at the same position as the side joining portion S in the longitudinal direction X. The crotch portion B typically includes regions in which leg opening portions LH, which are recesses for forming, are formed in both side edge portions 10S of the outer body 10 along the longitudinal direction X, that is, leg edge portions LS, and includes a excretory portion facing portion that is arranged to face excretory portions of the wearer' S penis, etc., when the diaper 1 is worn.
In the present invention, the abdomen-side portion a, the crotch portion B and the back-side portion C may be regions in which the diaper 1 in the developed and elongated state is trisected in the longitudinal direction X.
In the present embodiment, as shown in fig. 2, the abdominal portion a and the back portion C each have: an ilium region D2 corresponding to a portion of the wearer from the iliac crest to the anterior superior iliac spine; a waist region D1 located outside the region D2 in the longitudinal direction X (above the diaper 1); and a buttock region D3 located on the inner side (lower side of the diaper 1) in the longitudinal direction X than the region D2. The iliac crest and anterior superior spine are terms of digger science as referred to herein. The waist region D1 is located outermost in the longitudinal direction X of each of the abdomen-side portion a and the back-side portion C, and includes one of the two ends in the longitudinal direction X of the diaper 1, i.e., the longitudinal end 1E. The longitudinal end 1E of the diaper 1 is also the longitudinal end of the outer package 10.
In the present invention, the waist region D1, the ilium region D2, and the hip region D3 may be regions in which the ventral portion a or the dorsal portion C (a portion at the same position as the side joining portion S in the longitudinal direction X) is trisected in the longitudinal direction X.
In the present embodiment, the abdomen portion a and the back portion C are configured to have substantially the same structure, and the description of either one can be applied to the other unless otherwise specified.
In the present embodiment, the absorbent main body 2 has a rectangular shape in plan view, and is disposed in the central portion of the outer body 10 in the lateral direction Y so that its longitudinal direction coincides with the longitudinal direction X of the diaper 1, and extends in the longitudinal direction X from the abdomen side portion a to the back side portion C. The absorbent body 2 is joined to the outer body 10 by an adhesive.
As shown in fig. 4 and 5, the absorbent body 2 includes an absorber 5, a liquid-permeable front sheet 3 disposed on the skin-facing surface side of the absorber 5, and a liquid-impermeable (specifically, liquid-impermeable, or water-repellent) back sheet 4 disposed on the non-skin-facing surface side of the absorber 5. The absorbent body 5 includes at least an absorbent core mainly composed of a water-absorbent material such as wood pulp or a water-absorbent polymer, and the liquid-permeable core-wrap sheet covering the outer surface of the absorbent core may include paper, nonwoven fabric, or the like. As the constituent member of the absorbent main body 2, a member commonly used in such an absorbent article can be used without particular limitation. For example, various nonwoven fabrics, apertured films, and the like can be used as the front sheet 3. As the back sheet 4, a resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used. The constituent members of the absorbent body 2 are integrally formed with each other by a known joining method such as an adhesive.
A pair of leakage preventing cuffs 6, 6 each comprising a liquid-resistant or water-repellent and breathable leakage preventing cuff-forming sheet 60 is provided on both sides of the skin-facing surface (front sheet 3 side) of the absorbent main body 2 along the longitudinal direction X. At the free end portion of each leakage preventing cuff 6, 1 or more thread-like leakage preventing cuff forming elastic members 61 are extendably fixed in the longitudinal direction X. The leakage preventing cuff 6 is contracted by the elastic member 61 and stands up toward the skin side of the wearer at least in the crotch portion B, thereby preventing the outflow of body fluid to the outside in the lateral direction Y. The pants-type absorbent article of the present invention may not have the leakage preventing cuffs 6.
Hereinafter, the exterior body 10, which is the main part of the diaper 1, will be described in detail. The outer body 10 includes an outer sheet 11 disposed at a position relatively distant from the absorber 5, and an inner sheet 12 disposed at a position relatively close to the absorber 5.
In the present embodiment, in the developed and extended state of the diaper 1 shown in fig. 2, the outer body 10 has a rectangular shape in which the portion corresponding to the crotch portion B (the central region in the longitudinal direction X) is curved in an arc shape protruding toward the center in the lateral direction Y, and the portion corresponding to the abdomen portion a and the back portion C (the end region in the longitudinal direction X) has a length in the lateral direction Y longer than the longitudinal direction X, and the outer body 10 as a whole has an hourglass shape.
As shown in fig. 3 and 5, the outer sheet 11 includes a abdomen-side outer sheet 11A corresponding to the abdomen-side portion a, a crotch outer sheet 11B corresponding to the crotch portion B, and a back-side outer sheet 11C corresponding to the back-side portion C. The outer layers 11A, 11B, 11C form the outer surface of the diaper 1. The outer layer sheets 11A, 11B, and 11C are integrally joined to each other by a known joining method such as an adhesive, heat sealing, high-frequency sealing, or ultrasonic sealing at the overlapping portions thereof, with the end portions in the longitudinal direction X overlapping each other. In the overlapping portion of the sheets 11A, 11C and the sheet 11B, the sheet 11B located at the center in the longitudinal direction X is located on the side facing the absorbent main body 2, and the non-skin-facing surfaces of both end portions in the longitudinal direction X of the sheet 11B are covered with the sheets 11A, 11C, respectively (see fig. 5).
The inner sheet 12 includes a ventral inner sheet 12A corresponding to the ventral portion a, and a dorsal inner sheet 12C corresponding to the dorsal portion C. The two sheets 12A and 12C are arranged in a state of being separated from each other.
In the present invention, the outer sheet 11 and the inner sheet 12 may be formed of 1 continuous sheet instead of including such a plurality of sheets.
The following description of the outer layer sheet 11 is applicable to the respective sheets 11A, 11B, and 11C unless otherwise specifically described. The following description of the inner layer sheet 12 applies to the abdominal inner layer sheet 12A and the back inner layer sheet 12C unless otherwise specifically described.
The outer sheet 11 and the inner sheet 12 may be the same type of sheet or different types of sheet. In the present embodiment, the former includes a stretchable sheet, and the latter is composed of a non-stretchable sheet, and the latter are sheets of different types from each other, as described later.
The plurality of sheets 11A, 11B, 11C constituting the outer layer sheet 11 may be the same type of sheets as each other or may be different types of sheets. In the present embodiment, the abdominal outer layer sheet 11A and the back outer layer sheet 11C are the same type of sheet (stretchable sheet 20), but the two sheets 11A, 11C and the crotch outer layer sheet 11B are different types of sheets (non-stretchable sheets).
The plurality of sheets 12A and 12C constituting the inner sheet 12 may be the same type of sheets as each other or may be different types of sheets. In the present embodiment, the abdominal inner layer sheet 12A and the back inner layer sheet 12C are the same type of sheet (non-stretchable sheet).
In the present specification, "the same type of sheet" refers to sheets having the same manufacturing process, type of constituent fibers, fiber diameter and length of constituent fibers, thickness or grammage of the sheet, and the like. At least 1 of them is different, and is "different kinds of tablets".
The grammage of the outer layer sheet 11 (the grammage of the laminated structure in the case where the outer layer sheet 11 is of the laminated structure) is not particularly limited, and is preferably 20g/m 2 The above is more preferably 30g/m 2 Above, and is preferably 60g/m 2 Hereinafter, more preferably 55g/m 2 The following is given.
The grammage of the inner layer sheet 12 (the grammage of the laminated structure in the case where the inner layer sheet 12 is of the laminated structure) is not particularly limited, and is preferably 13g/m 2 The above is more preferably 15g/m 2 Above, and is preferably 30g/m 2 Hereinafter, more preferably 25g/m 2 The following is given.
At least a part of the outer body 10 is a composite stretchable portion 10E having stretchability in the lateral direction Y. In the composite stretch unit 10E, as shown in fig. 4, the outer layer sheet 11 and the inner layer sheet 12 are joined by a plurality of joining portions 13 arranged at intervals in the lateral direction Y.
The composite expansion and contraction part 10E has an expansion and contraction member that imparts expansion and contraction to the composite expansion and contraction part 10E. In other words, the composite stretchable portion 10E is a portion of the outer body 10 in which a stretchable member having stretchability in the lateral direction Y is disposed. The stretchable member is not particularly limited, and may be, for example, a stretchable sheet, or a filament-like or belt-like elastic member. The composite expansion and contraction portion 10E may have a plurality of types of the expansion and contraction members (for example, both the expansion and contraction sheet and the elastic member). For example, in a case where at least one of the outer sheet 11 and the inner sheet 12 is a stretchable sheet (stretchable member) having stretchability in the lateral direction Y, the arrangement portion of the stretchable sheet may be a composite stretchable portion 10E. In the case where a plurality of elastic members (stretchable members) are extendably fixed in the lateral direction Y between the two sheets 11 and 12, the arrangement portion of the elastic members may be the composite stretchable portion 10E even when both the two sheets 11 and 12 are not stretchable sheets.
In the present embodiment, the outer sheet 11, more specifically, the abdominal outer sheet 11A and the back outer sheet 11C are each composed of an extensible sheet 20 (see fig. 6) described later, and have extensibility in the lateral direction Y, whereas the inner sheets 12 (12 a, 12C) are each composed of a non-extensible sheet, and do not have extensibility. That is, in the present embodiment, the outer layer sheet 11 is a stretchable member that imparts stretchability to the composite stretchable portion 10E, and the inner layer sheet 12 is not the stretchable member. In the outer case 10, the portions where the outer layers 11A and 11C as stretchable sheets and the inner layers 12A and 12C as non-stretchable sheets are joined via the joining portions 13 have stretchability in the transverse direction Y as a whole, and are composite stretchable portions 10E. Therefore, in the present embodiment, the arrangement portion of the outer layer sheets 11A and 11C, that is, the arrangement portion of the stretchable sheet 20 is the composite stretchable portion 10E.
In describing the stretchable sheet that can be used as a component of the composite stretchable portion 10E, the stretchable sheet preferably has a maximum elongation of 50% or more in the transverse direction Y, and after the sheet is elongated to an elongation of 100% in the transverse direction Y, the elongation recovery at the time of shrinkage (i.e., the elongation recovery at the time of 100% elongation) is preferably at least 70% or more.
The maximum elongation of the stretch panel in the transverse direction Y is high and the elongation recovery is high compared to the longitudinal direction X. More specifically, the stretchable sheet preferably has a maximum elongation of 50% or more and an elongation recovery of 70% or more in the transverse direction Y, and is shrunk after elongation, but is not shrunk after elongation in the longitudinal direction X. The elongation recovery of the sheet was measured by the following measurement method.
< method for measuring elongation recovery >
From the sheet to be measured (stretchable sheet), a specimen sheet having a length of 50mm and a width of 25mm was prepared. The sample sheet was fixed between chucks (chuck interval K0) of a tensile tester (orihentec co., ltd. Of "tenston" RTC-1150A) in a non-elongated and non-relaxed state, the sample sheet was pulled by expanding the space between chucks at a tensile speed of 300mm/min, the space between chucks was contracted at the same speed as the tensile speed after the sample sheet was elongated to a length K2 (=k0×2) at 100% elongation of the sample sheet, and the length of the sample sheet at the time when the tensile stress became 0 was regarded as the length K1 after elongation recovery. The elongation recovery at 100% elongation of the sheet to be measured was calculated by the following equation.
Elongation recovery at 100% elongation (%) = [ (K2-K1)/(K2-K0) ] x 100 ]
As the expansion sheet, for example, it is preferable to use: (1) Stretchable nonwoven fabric having stretchable fiber layers integrally formed on both or one side of an elastic fiber layer; (2) Stretchable nonwoven fabric having stretchable fibrous layers integrally formed on both or one side of a mesh-like elastic sheet; (3) Stretchable nonwoven fabric comprising an elastic sheet comprising an elastic film and an extensible fibrous layer integrally formed on both or one side of the elastic sheet; (4) A stretchable nonwoven fabric comprising a plurality of elastic filaments arranged so as not to cross each other and extending in one direction, and a stretchable fibrous layer bonded to the elastic filaments over the entire length of the elastic filaments in a substantially non-stretched state.
The term "extensible fiber layer" as used herein includes not only a fiber layer that is extensible before being integrated with a material having elasticity, but also a fiber layer that is extensible by machining or the like after being integrated with a material having elasticity.
As a method of integrating the elastic fiber layer and the stretchable fiber layer, for example, a method of laminating them and interlacing fibers by hydroentanglement, hot air or the like, and a method of joining them by hot embossing, an adhesive, ultrasonic waves or the like can be exemplified.
Fig. 6 shows a stretchable sheet 20 as an example of the stretchable sheet. The stretchable sheet 20 corresponds to the stretchable nonwoven fabric of (4) above. The stretchable panel 20 is constituted by a fibrous layer stretchable in the transverse direction Y and a plurality of elastic filaments 23 joined to one surface of the fibrous layer and extending in the transverse direction Y. In the embodiment shown in fig. 6, the fiber layer includes 2 opposite fiber sheets 21 and 22, and a plurality of elastic filaments 23 are arranged between the two fiber sheets 21 and 22.
The stretchable sheet 20 can be manufactured by the method described in japanese patent application laid-open No. 2009-61743, for example. Specifically, for example, a plurality of elastic filaments 23 in a molten state spun from a spinneret are drawn and extended at a predetermined speed, and before the elastic filaments 23 are solidified, the elastic filaments 23 are welded to the fiber sheets 21 and 22 so that the elastic filaments 23 do not intersect each other, and then the two sheets 21 and 22 to which the elastic filaments 23 are welded are extended along the extending direction of the elastic filaments 23, whereby the stretchable sheet 20 can be manufactured.
The stretchable panel 20 has stretchability in one direction (the lateral direction Y) as a whole. In the stretchable sheet 20, the pitch P (see fig. 6) of the elastic filaments 23 imparting stretchability to the stretchable sheet 20 in the transverse direction Y is relatively short, and the plurality of elastic filaments 23 are arranged at a high density in the longitudinal direction X, and by such arrangement of the elastic filaments 23, the stretchable sheet 20 as a whole has stretchability in the transverse direction Y. The pitch P of the elastic filaments 23, that is, the distance P between centers of 2 elastic filaments 23, 23 adjacent to each other in the longitudinal direction X is preferably 3mm or less, more preferably 2mm or less, from the viewpoint of imparting stretchability to the whole stretchable sheet 20. The lower limit of the pitch P of the elastic filaments 23 is not particularly limited, but is preferably 0.5mm or more, more preferably 1mm or more.
The 2 fibrous sheets 21, 22 constituting the stretchable sheet 20 are each stretchable in the same direction as the extending direction (transverse direction Y) of the elastic filaments 23. As used herein, "capable of elongation" includes: (a) The constituent fibers of the fiber sheets 21, 22 themselves extend; (b) Even if the constituent fibers themselves do not elongate, the fibers bonded at the intersections are separated from each other, or the three-dimensional structure formed of a plurality of fibers by the bonding of the fibers to each other is structurally changed, or the constituent fibers are torn, and the entire fiber sheets 21 and 22 elongate.
The elastic filaments 23 are a material in which an elastic resin is stretched in a molten or softened state. The plurality of elastic filaments 23 are continuously arranged over the entire length of the stretchable panel 20 in the transverse direction Y. The plurality of elastic filaments 23 are arranged so as to extend in one direction (the lateral direction Y) without intersecting each other. The elastic filaments 23 are joined to the 2 sheets 21, 22 in a substantially non-stretched state. The bonding of the elastic filaments 23 to the fiber sheets 21, 22 is accomplished by welding the constituent fibers (inelastic fibers) of the two sheets 21, 22 to the elastic filaments 23 in a state of being embedded in the elastic filaments 23, instead of bonding with an adhesive such as a hot melt adhesive. Therefore, no adhesive exists between the fiber sheets 21, 22 (extensible fiber layer mainly composed of inelastic fibers) and the elastic filaments 23 bonded to them.
The stretchable panel 20 is stretchable in the same direction (transverse direction Y) as the direction in which the elastic filaments 23 extend. The stretchability of the stretchable panel 20 is represented by the elasticity of the elastic filaments 23. When the stretchable sheet 20 is stretched in the same direction as the extending direction of the elastic filaments 23, the elastic filaments 23 and the fibrous sheets 21, 22 are stretched. When the stretch of the stretchable sheet 20 is released, the elastic filaments 23 contract, and the fiber sheets 21 and 22 return to the state before the stretch in accordance with the contraction. In the stretchable sheet 20, as described in japanese patent application laid-open No. 2009-61743, when the stretchable sheet is manufactured, the fiber sheets 21 and 22 are stretched in the extending direction of the elastic filaments 23, and therefore, a part of the bonds between the fibers of the two sheets 21 and 22 is broken, and thus, an "extension margin" is provided in the two sheets 21 and 22. Specifically, in the fiber sheets 21 and 22 of the stretchable sheet 20 manufactured by such stretching treatment, as shown in fig. 9, the high-density portions 24 having relatively high density of constituent fibers and the low-density portions 25 having relatively low density of constituent fibers are alternately formed in the extending direction of the elastic filaments 23, so that the low-density portions 25 are easily deformed in the fiber sheets 21 and 22 and can follow the stretching of the elastic filaments 23. Therefore, when the stretchable sheet 20 is stretched in the extending direction (the lateral direction Y) of the elastic filaments 23, the stretchable sheet 20 can be stretched with little shrinkage, so-called tenter, in the lateral direction Y. Further, the expansion and contraction sheet 20 has small variation in apparent thickness accompanying expansion and contraction, and can be a flat sheet even if it expands and contracts. In the embodiment shown in fig. 9, the stretchable sheet 20 is used as the outer sheet 11, and the outer sheet 11 has the above-described features. Details regarding the manner shown in fig. 9 are described later.
The 2 fibrous sheets 21 and 22 constituting the stretchable sheet 20 can be nonwoven fabrics of staple fibers. Examples of the nonwoven fabric include a hot air nonwoven fabric, a hot rolled nonwoven fabric, a spun-laced nonwoven fabric, a spun-bond nonwoven fabric, and a melt blown nonwoven fabric. The two sheets 21, 22 may be of the same kind or of different kinds.
The elastic filaments 23 constituting the stretchable sheet 20 are, for example, materials made of thermoplastic elastomer, rubber, or the like. In particular, when a thermoplastic elastomer is used as a raw material, the thermoplastic resin can be melt spun using an extruder similarly to a usual thermoplastic resin, and the elastic filaments thus obtained are easily heat-fused, and therefore are suitable for the stretchable sheet 20. Examples of the thermoplastic elastomer include styrene-based elastomers such as SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), SEPS (styrene-ethylene-propylene-styrene), olefin-based elastomers (ethylene-based α -olefin elastomer, propylene-based elastomer obtained by copolymerizing ethylene, butene, octene, etc.), polyester-based elastomer, polyurethane-based elastomer, etc., and 1 kind of these may be used alone or 2 or more kinds may be used in combination. In addition, a core-sheath type or side-by-side type composite fiber composed of these resins can also be used.
In the present embodiment, as described above, the inner sheet 12 (12A, 12C) is composed of a non-stretchable sheet. The crotch outer layer sheet 11B, which is a part of the outer layer sheet 11, is also made of a non-stretchable sheet. The non-stretchable sheet preferably has an elongation recovery ratio of 20% or less as measured by the above < method for measuring elongation recovery ratio >, or is broken before 100% elongation.
As the non-stretchable sheet, nonwoven fabrics of various methods can be used, and examples thereof include spun-bonded nonwoven fabrics, hot air nonwoven fabrics, needle punched nonwoven fabrics, and the like. The non-stretchable sheets ( inner sheets 12A, 12C, and outer sheet 11B) may have a single-layer structure, or may have a laminated structure in which 2 or more sheets (nonwoven fabrics) are laminated, typically a single-layer structure.
In the present embodiment, a plurality of waist gather forming elastic members 7 are arranged in the lateral direction Y so as to be stretchable in the portions corresponding to the abdomen portion a and the back portion C (the waist portion D1, the ilium portion D2, and the hip circumference portion D3) of the composite stretchable portion 10E (the outer body 10). The plurality of elastic members 7 are fixed by an adhesive in the lateral direction Y so as to be extendable between the outer layer sheets 11 (11A, 11C) and the inner layer sheets 12 (12A, 12C) constituting the outer body 10, and are arranged at intervals in the longitudinal direction X. That is, in the present embodiment, the composite stretchable portion 10E includes, as a stretchable member for imparting stretchability to the composite stretchable portion 10E, not only the stretchable sheet 20 constituting the outer sheet 11, but also the elastic member 7 disposed between the outer sheet 11 and the inner sheet 12 so as to be stretchable in the lateral direction Y.
In the natural state or the wearing state of the diaper 1, a plurality of gathers (wrinkles) extending in a direction intersecting the contraction direction of the elastic members 7 are formed in the portions of the outer body 10 corresponding to the abdomen-side portion a and the back-side portion C by contraction of the elastic members 7, whereby the gathers form substantially continuous annular waistline gathers throughout the entire circumference of each of the abdomen-side portion a and the back-side portion C. The elastic member 7 is subjected to expansion/contraction inhibition processing such as cutting and heating at a portion overlapping with the absorber 5 (absorbent body 2) in a plan view (see fig. 3).
In the present embodiment, 1 or more elastic members 8 for forming leg wrinkles are disposed in the leg edge portions LS forming the opening edge portions of each of the pair of leg opening portions LH, LH. The elastic member 8 is extendably fixed between the outer layer sheet 11 (11A, 11C) and the inner layer sheet 12 (12A, 12C) by an adhesive. In the natural state or the wearing state of the diaper 1, a plurality of wrinkles (gathers) extending in a direction intersecting the contraction direction of the elastic member 8 are formed in the portion of the outer body 10 constituting the opening edge portion of the leg opening portion LH by contraction of the elastic member 8, whereby the wrinkles form substantially continuous annular leg gathers throughout the entire circumference of the opening edge portion of the leg opening portion LH.
As materials for the various elastic members in the diaper 1 represented by the elastic members 7, 8, various known elastic materials commonly used in such an absorbent article can be used without particular limitation unless otherwise specified, and examples thereof include synthetic rubbers such as styrene-butadiene, isoprene, chloroprene, and the like, natural rubber, EVA, stretchable polyolefin, polyurethane, and the like. As the form of the elastic member, a thread-like (filament rubber or the like) or a band-like (rubber strip or the like) elastic member having a rectangular, square, circular, polygonal shape or the like in cross section, a multifilament-like elastic member or the like can be preferably used.
At least one of the abdomen side portion a and the back side portion C is provided with an outer body folded-back portion 14, and the outer body folded-back portion 14 includes a portion in which the composite stretch unit 10E is folded back so as to make the inner layer sheet 12 inside. In the present embodiment, as shown in fig. 2 and 5, the outer body folded-back portion 14 is provided on both the abdominal portion a and the back portion C. Fig. 7 shows a cross section of the outer body folded-back portion 14 of the abdomen side portion a along the transverse direction Y, and fig. 8 shows a perspective view of the outer body folded-back portion 14 viewed from the outer surface side 14a thereof. Fig. 7 and 8 each schematically show a natural state of the diaper 1 (a state in which no external force is applied to the diaper 1), that is, a state of the outer body folded-back portion 14 when the elastic member and the stretchable member such as the stretchable sheet provided in the outer body 10 are in a non-stretched state. Hereinafter, the outer-body folded-back portion 14 of the abdomen portion a will be described as an example, and the description is applicable to the outer-body folded-back portion 14 of the back portion C unless otherwise specified.
The outer package folded-back portion 14 is a portion formed by folding back the composite stretchable portion 10E having a double-layer structure including the outer layer sheet 11 (11A, 11C) and the inner layer sheet 12 (12A, 12C), and includes a 4-layer structure including 4 sheets. The exterior body folded-back portion 14 is divided into: an outer surface side 14a which is located on the outer side in the thickness direction than the folded-back bending line of the composite stretchable portion 10E and forms the outer surface (non-skin-facing surface) of the diaper 1; and an inner surface side 14b including the folded back composite stretchable portion 10E, which is located further inward in the thickness direction than the bending line and forms an inner surface (skin-facing surface) of the diaper 1.
In the present embodiment, the outer sheet 11 and the inner sheet 12 each have an extension portion extending outward in the longitudinal direction X from the longitudinal end 5E of the absorber 5, and the extension portions of the two sheets 11 and 12 are folded back inward to form the outer-body folded back portion 14 by folding back the inner sheets 12A and 12C. The longitudinal end 1E of the diaper 1 coincides with the fold line of the exterior body 10 at the fold-back. Therefore, in the present embodiment, the outer body folded-back portion 14 is disposed at least in the waist region D1 which is an end portion in the longitudinal direction X of the diaper 1.
In the present invention, the outer body folded-back portion 14 may be disposed not only in the waist region D1 but also in the ilium region D2 and the hip region D3.
In the present embodiment, the length in the longitudinal direction X of the portion of the inner sheet 12 on the inner surface side 14b is longer than that of the outer sheet 11.
In the present invention, the relationship between the lengths of the two sheets 11 and 12 on the inner surface side 14b of the outer package folded-back portion 14 is not particularly limited, and the outer sheet 11 may be longer than the inner sheet 12, or the two sheets 11 and 12 may have the same length, contrary to the manner shown in the drawings.
In the present embodiment, the composite stretchable portion 10E, that is, the arrangement portion of the stretchable sheet 20 in the exterior body 10 has all of the following configurations (1) to (3).
(1) The outer layer sheet 11 (11A, 11C) and the inner layer sheet 12 (12A, 12C) have a structure in which they are joined by a plurality of joining portions 13 arranged at intervals in both the longitudinal direction X and the transverse direction Y (see fig. 4 and 8).
(2) The outer layer sheet 11 (11A, 11C) is composed of a stretchable sheet 20 (see fig. 6) having stretchability in the transverse direction Y, and the inner layer sheet 12 (12A, 12C) is composed of a non-stretchable sheet.
(3) Between the outer sheet 11 (11A, 11C) and the inner sheet 12 (12A, 12C), a plurality of elastic members 7 extending in the lateral direction Y are arranged at intervals in the longitudinal direction X, and each elastic member 7 is fixed so as to be extendable in the lateral direction Y without passing through the joint portion 13. In other words, the plurality of joint portions 13 are arranged at intervals in the lateral direction Y to form a row, the plurality of joint portions 13 extending in the lateral direction Y are arranged at intervals in the longitudinal direction X, and the rows of joint portions 13 and the elastic members 7 are alternately arranged in the longitudinal direction X (see fig. 5 and 8). The elastic member 7 is bonded to the two sheets 11 and 12 by an adhesive.
As shown in fig. 7 and 8, the inner sheet 12 has a folded structure including a plurality of concave portions 120 having joining portions 13 at the bottom and extending in the longitudinal direction X, and convex portions 121 located between the concave portions 120 and having a bent portion 12P of the inner sheet 12 as the top, in the composite stretch portion 10E in a natural state. The ridge portion 121 is a portion located in the inner layer sheet 12 at a non-formed portion of the joint portion 13, and is a portion protruding to the opposite side from the outer layer sheet 11, and the ridge portion 121 is hollow, that is, a space portion between the outer layer sheet 11 and the inner layer sheet 12 in the ridge portion 121.
On the other hand, in the composite stretch unit 10E in the natural state, as shown in fig. 9, the outer sheet 11 (stretch sheet 20) has a plurality of bent portions 11P in a region overlapping with 1 ridge 121 of the inner sheet 12 in a plan view (projection view in the thickness direction of the outer sheet 11). That is, in the composite stretch unit 10E in the natural state, the number of bent portions per unit length in the lateral direction Y is greater for the outer sheet 11 (stretch sheet 20) than for the inner sheet 12 (non-stretch sheet). That is, in the composite stretch unit 10E in the natural state, the outer sheet 11 also has a corrugated structure, which is composed of a plurality of concave portions extending in the longitudinal direction X and convex portions located between the concave portions and having the curved portion 11P of the outer sheet 11 as the top, as in the inner sheet 12, and the pitch (interval) of the convex portions or concave portions in the outer sheet 11 is shorter than the pitch (interval) in the inner sheet 12.
In the composite stretch unit 10E in a natural state, one of the reasons why the outer sheet 11 is deformed so as to bend at a plurality of bending portions 11P formed at intervals in the lateral direction Y is that the stretch sheet 20 forming the outer sheet 11 alternately has "2 types of sites having mutually different shapes or physical properties" in the lateral direction Y.
In the present embodiment, as described above, in the manufacturing process of the stretchable sheet 20, the stretchable sheet 20 is stretched in the extending direction (the lateral direction Y) of the elastic filaments 23, and by this stretching process, as shown in fig. 9, in the fibrous sheets 21 and 22 constituting the stretchable sheet 20, as shown in an enlarged scale, the high-density portions 24 having relatively high density of constituent fibers and the low-density portions 25 having relatively low density of constituent fibers are alternately formed in the extending direction (the lateral direction Y) of the elastic filaments 23, and it is considered that such a difference in fiber density promotes bending deformation of the stretchable sheet 20 (the outer sheet 11). In the natural state of the expansion and contraction sheet 20, as shown in fig. 9, typically, the high-density portion 24 forms a curved portion 11P as a starting point of the bending, and the low-density portion 25 is located between the adjacent 2 curved portions 11P, 11P. In the enlarged view of the portion surrounded by the broken line in fig. 9, only the fiber sheets 21 and 22 are shown as the constituent members of the stretchable sheet 20 from the viewpoint of easy understanding, and the elastic filaments 23 are not shown, but in fact, the elastic filaments 23 are integrally arranged between the fiber sheets 21 and 22.
Examples of the "shape or physical property" among the "shape or physical property 2 portions different from each other" that can promote bending deformation of the outer layer sheet 11 (stretchable sheet 20) include, for example, rigidity, inter-fiber distance, grammage, presence or absence of stretching treatment, the number of fiber ends, and flatness, in addition to the "fiber density" described above.
The composite stretch unit 10E is typically produced by joining the elastic member 7 to the non-stretchable inner sheet 12 in a state of being stretched in the lateral direction Y, joining the outer sheet 11 (the stretch sheet 20) to the joining portion 13 in a state of being stretched in the lateral direction Y, and then releasing the elastic member (the elastic member 7 and the outer sheet 11) from the stretched state to a natural state. In the natural state of the composite stretchable portion 10E thus manufactured, the inner sheet 12 is deformed in a curved manner between the joining portions 13, 13 adjacent to each other in the lateral direction Y by contraction of the stretchable member in the lateral direction Y, and the ridge portions 121 having the curved portion 12P as the top and the concave bar portions 120 having the joining portions 13 at the bottom are alternately arranged in the lateral direction Y in the deformed inner sheet 12. On the other hand, the outer sheet 11 composed of the stretchable sheet 20 is deformed so that the plurality of curved portions 11P formed at intervals in the lateral direction Y are curved like the inner sheet 12, but the pitch of the irregularities is shorter than that in the inner sheet 12, and the height of the ridge portions of the outer sheet 11 is lower than that of the ridge portions 121 of the inner sheet 12 (the depth of the concave portions of the outer sheet 11 is shallower than that of the concave portions 120 of the inner sheet 12), so that the outer sheet 11 can be regarded as a flat sheet having no irregularities in some cases.
In this way, the outer package folded-back portion 14 has a laminated structure formed by folding back the composite stretchable portion 10E having a concave-convex structure in a natural state, and therefore has excellent cushioning properties and air permeability. The surface of the outer body folded-back portion 14 of the diaper 1, which is to be brought into contact with the skin of the wearer, is formed of the outer sheet 11 having a relatively small degree of concavity and convexity, and is typically substantially flat, so that the burden on the skin of the wearer is small, and the skin is less likely to be creased even for a wearer who is in a sleeping position. Since the diaper 1 is constituted by the outer body folded-back portion 14 having such a characteristic, even if the wearer is asleep, the skin is not easily creased, and the wearer is not easily stuffy.
In the composite stretch unit 10E in a natural state, the number of the bent portions 11P (the total number of the bent portions existing on one surface side and the bent portions existing on the other surface side of the outer sheet 11) existing in the region overlapping 1 ridge portion 121 in a planar view (between 2 joint portions 13, 13 adjacent in the lateral direction Y) in the outer sheet 11 (the stretch sheet 20) is preferably 2 or more, more preferably 3 or more from the viewpoint of further reliably exhibiting the effect of the action of the outer body folded-back portion 14, although it depends on the types and grammage of the constituent members of the composite stretch unit 10E typified by the outer sheet 11, the elongation characteristics of the stretch sheet 20 and the elastic member 7, and the like. The upper limit of the number of the bent portions 11P is not particularly limited, but is preferably 10 or less, more preferably 5 or less, from the viewpoint of preventing the strength of the expansion and contraction sheet 20 from decreasing with the increase of the low-density portions 25.
The length (width) of the 1 ridge 121 in the lateral direction Y, that is, the interval between 2 joining portions 13, 13 adjacent to each other in the lateral direction Y is preferably 2mm or more, more preferably 3mm or more, and preferably 15mm or less, more preferably 10mm or less.
The above-described "number of bent portions 11P in the outer layer sheet 11" can be measured by visually counting the number of bent portions 11P formed in the region overlapping 1 ridge 121 in a planar view (between 2 joint portions 13, 13 adjacent to each other in the lateral direction Y) during a change from the extended state to the natural length state (non-extended state) of the outer layer sheet 11, for example, by observing a cross section of the outer layer sheet 11 in the extension-and-contraction direction along the thickness direction with a microscope at an arbitrary magnification. Hereinafter, this measurement method is also referred to as "measurement method a". In the measurement method a, when the apparent thickness of the outer sheet 11 is 2 times or more the thickness of the outer sheet 11 in an extended state (a state in which the bent portion 11P is not substantially formed), the height of the ridge portion of the outer sheet 11 with the bent portion 11P as the top is equal to or lower than the height of the ridge portion 121 of the inner sheet 12 overlapping the ridge portion in a plan view, in the bent portion 11P as the object to be counted.
The measurement method a is difficult to apply when the size of the bent portion 11P is relatively small and it is difficult to visually recognize. For example, in the case where the outer sheet 11 is a stretchable sheet 20 manufactured by a method accompanied by a stretching process described in japanese patent application laid-open No. 2009-61743, the bent portions 11P are likely to be small, and it is difficult to measure the number of the bent portions 11P by the measurement method a in many cases. In this case, the number of the high-density portions 24 and the low-density portions 25 (hereinafter also referred to as "measurement method B") can be measured by cutting out the composite stretchable portion 10E (the portion of the outer body 10 in which the stretchable member having stretchability in the lateral direction Y is arranged) from the outer body 10, and putting the cut composite stretchable portion 10E into the stretched state. That is, referring to fig. 9, since the curved portion 11P is formed by deformation of the low-density portion 25 without deformation of the high-density portion 24 due to expansion and contraction of the elastic filament 23, the ridge portion or the concave portion of the 1 outer layer sheet 11 (expansion and contraction sheet 20) is formed with respect to "a combination of 2 low- density portions 25 and 1 high-density portion 24" or "a combination of 1 low- density portion 25 and 2 high-density portion 24". Therefore, in the measurement method B, the outer sheet 11 (the stretchable sheet 20) in an extended state is observed, the number of the high-density portions 24 and the low-density portions 25 in this state are counted, and based on the counted number and the number of the joint portions 13, the "number of the bent portions 11P in the outer sheet 11" can be calculated.
When the composite stretchable portion 10E (the outer package folded-back portion 14) is compressed in the thickness direction, specifically, for example, when a load of 3kPa is applied to the composite stretchable portion 10E and the composite stretchable portion is compressed in the thickness direction, the outer layer sheet 11 (the stretchable sheet 20) is preferably reduced in thickness more than the inner layer sheet 12. The reduction rate of the thickness is calculated by the following formula.
Reduction rate of thickness (%) = { (thickness of sheet before compression-thickness of sheet in compressed state)/thickness of sheet before compression } ×100
The outer sheet 11 (stretchable sheet 20) forms a surface of the outer body folded-back portion 14, and is a portion that comes into contact with the skin of the wearer of the diaper 1, and the outer sheet 11 is easily deformed by compression at a higher rate of reduction in the thickness of the outer sheet 1 than the inner sheet 12, that is, is easily flattened when compressed under a constant load, and thus is less likely to form an indentation in the skin of the wearer of the diaper 1. On the other hand, since the inner sheet 12 has a lower reduction rate in thickness than the outer sheet 11, the shape of the ridge portion 121 formed in a natural state is easily maintained, and the cushioning property and air permeability of the outer body folded-back portion 14 (the composite stretch portion 10E) can be further improved.
The magnitude relation of "the reduction rate of the thickness of the outer layer sheet 11 > the reduction rate of the thickness of the inner layer sheet 12" can be established by configuring the outer layer sheet 11 and the inner layer sheet 12 according to the description of the present specification.
The joint 13 may be formed by an adhesive such as a hot melt adhesive, that is, even if the two sheets 11 and 12 are joined to each other by an adhesive, in the present embodiment, the joint 13 is formed by a welded portion of the two sheets 11 and 12. When the joining portion 13 is formed of an adhesive, there is a concern that the adhesive oozes out, and by forming the welding portion, such a concern can be eliminated, and the burden on the skin of the wearer of the diaper 1 can be further reduced.
In the joint 13 formed by the welded portion of the two sheets 11, 12, the two sheets 11, 12 are formed in a film shape or a shape based on the film shape. The formation of the joint 13 by welding the two sheets 11 and 12 can be performed by a known welding method of resin sheets such as embossing with heat and ultrasonic sealing.
As shown in fig. 8, the joint 13 preferably extends in the longitudinal direction X. With this structure, the cushioning properties of the outer body folded-back portion 14 are further improved, and for example, when the wearer of the diaper 1 is in a sleeping position or the like, a good cushioning feeling can be obtained when a load is applied to the outer body folded-back portion 14. The term "extending in the longitudinal direction X" as used herein includes: 1) The plurality of joint portions 13 are arranged at intervals in the longitudinal direction X, and form rows of joint portions 13 extending in the longitudinal direction X (see fig. 8); and 2) a mode (not shown) in which the joint portion 13 has a continuous linear shape (linear shape, curved shape, etc.) in a plan view. In the embodiment 1), the shape of the joint 13 in plan view is not particularly limited, and may be, for example, a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, or the like, in addition to the quadrangular shape shown in the figures. In the case of the embodiment 2) described above, the elastic member 7 can intersect with the continuous linear joint portion 13.
In the present embodiment, in the composite stretch unit 10E in the natural state, the ridge portions 121 constituting the folded structure of the inner sheet 12 are hollow as described above, as shown in fig. 7 and 8, and the hollow structure of the ridge portions 121 contributes to the improvement of the cushioning property and the air permeability of the outer body folded-back portion 14 to a large extent. The hollow structure of the raised strip 121 is preferably higher in rigidity than the outer sheet 11 (stretchable sheet 20) in the inner sheet 12 from the viewpoint of stably maintaining the hollow structure during wearing of the diaper 1.
The rigidity of the sheet constituting the composite stretch unit 10E (outer body 10) is measured by the following method.
< method for measuring rigidity >
From a sheet to be measured, specifically, for example, the outer sheet 11 (stretchable sheet 20) or the inner sheet 12, a test piece having a length of 150mm in the stretching direction (transverse direction Y of the absorbent article) of the composite stretchable portion 10E and a length of 30mm in the direction orthogonal to the stretching direction (longitudinal direction X of the absorbent article) and having a rectangular shape in plan view is cut out. The stretching direction is typically the same as the flow direction (machine direction MD) at the time of manufacturing the sheet. When the sheet to be measured is taken out from the absorbent article (composite stretchable portion), if the sheet to be measured is joined to another member, the joining of the sheet to be measured to the other member is invalidated by a heating device such as a dryer or by cold spraying, an organic solvent, or the like, and then the sheet to be measured is carefully peeled off from the other member.
The test piece was wound up so that the longitudinal direction of the test piece became the circumferential direction, and both ends of the test piece in the longitudinal direction were overlapped by 5mm to form a cylinder with a diameter of 45 mm. Then, 2 portions of the upper end and the lower end of the cylinder in the axial direction were fixed to a staple such as a 10-1M needle manufactured by maxco. Wherein the direction of the staple is made parallel to the circumferential direction. The prepared cylindrical measurement samples were placed in a compression tester such as "RTA-100" manufactured by ORIENTECCO., LTD., so that the axial directions of the measurement samples were aligned with the vertical directions. The measurement sample was compressed in the axial direction of the cylinder at a compression rate of 10mm/min by using a circular compression plate having a diameter of 70mm or more, and the maximum load (N/30 mm) exhibited during the compression was recorded. 5 measurement samples were prepared for each of the 1 measurement target pieces, and the respective maximum loads were measured, and the arithmetic average value of the maximum loads was used as the value of the rigidity of the measurement target piece.
The ratio of the rigidity of the inner sheet 12 to the rigidity of the outer sheet 11 (stretchable sheet 20) is 1.1 or more, more preferably 1.2 or more, and preferably 3.0 or less, more preferably 2.0 or less, on the premise of the former > the latter.
The rigidity of the outer sheet 11 (stretchable sheet 20) is preferably 10.0N or less, more preferably 8.0N or less, on the premise that the rigidity is lower than that of the inner sheet 12.
The rigidity of the inner sheet 12 is preferably 16.0N or less, more preferably 15.0N or less, on the premise that the rigidity of the outer sheet 11 (stretchable sheet 20) is higher.
As described above, in the present embodiment, the composite stretchable portion 10E has, as a stretchable member for imparting stretchability to the composite stretchable portion 10E as shown in fig. 8 and 9, the elastic member 7 which is arranged between the outer sheet 11 and the inner sheet 12 so as to be stretchable in the lateral direction Y, in addition to the outer sheet 11 (stretchable sheet 20), and the elastic member 7 contributes to the hollow structure of the ridge portion 121 being more stably maintained during wearing of the diaper 1, and further contributes to further improvement in the cushioning property and breathability of the outer body folded-back portion 14. That is, in the wearing of the diaper 1, since a part of the outer sheet 11 intrudes into the hollow portion of the ridge portion 121 in the inner sheet 12, the ridge portion 121 becomes substantially not hollow, and there is a concern that the cushioning property and air permeability of the outer body folded-back portion 14 may be lowered, whereas in the present embodiment, by disposing the elastic member 7 between the two sheets 11, 12, the intrusion of the outer sheet 11 into the hollow portion of the ridge portion 121 can be suppressed, and such a concern can be eliminated.
The interval 7P (see fig. 8) between adjacent elastic members 7, 7 in the longitudinal direction X is preferably 4mm or more, more preferably 5mm or more, and preferably 10mm or less, more preferably 8mm or less, from the viewpoint that the effect of improving the stability of the hollow structure of the ridge 121 produced by such elastic members 7 can be reliably exerted and excessive binding of the wearer by the excessive number of elastic members 7 can be prevented.
In order to reliably exert the predetermined effect of the present invention, particularly the action and effect of the outer package folded-back portion 14, it is preferable that the plurality of raised strips 121 of the outer package folded-back portion 14 extend similarly in the longitudinal direction X and maintain the hollow structure thereof. As one of the factors that affect the formation of the raised strip 121, there can be exemplified the expansion and contraction characteristics (expansion and contraction ratio, expansion and contraction stress, etc. of the expansion and contraction member) of the composite expansion and contraction portion 10E. Further, since the expansion and contraction characteristics of the composite expansion and contraction portion 10E are affected by the absorber 5 overlapping with the same in a plan view, the arrangement of the absorber 5 and the like must be considered in order to stably present the ridge 121 in a desired form.
In this regard, in the present embodiment, as shown in fig. 2 and 5, when the region sandwiched between the longitudinal ends 5E and 1E is the absorber non-placement region 5N in each of the abdominal portion a and the back portion C, which is located on the inner side in the longitudinal direction X than the longitudinal end 1E of the diaper 1, the stretch ratio of the stretch member that imparts stretchability to the composite stretch unit 10E is preferably lower in the portion located in the absorber non-placement region 5N than in the portion located in the absorber placement region adjacent to the absorber non-placement region 5N in the longitudinal direction X, from the above point of view.
The above-mentioned "absorber placement area" is an area where a virtual straight line (not shown) is superimposed on the absorber 5 when 1 virtual straight line (not shown) intersecting the abdominal portion a or the back portion C in the lateral direction Y is made, in other words, an area where a projection image of the absorber 5 in the lateral direction Y can be formed in the abdominal portion a or the back portion C. In the present embodiment, the regions other than the absorber non-placement region 5N in each of the abdominal portion a and the back portion C are the absorber placement regions.
The absorber non-placement region 5N is susceptible to the expansion and contraction member as compared with the absorber placement region because the absorber 5 having relatively high rigidity is not placed. Therefore, due to the expansion and contraction characteristics of the expansion and contraction member included in the composite expansion and contraction portion 10E, there is a possibility that the extending direction of the ridge portion 121 in the absorber non-placement region 5N becomes non-parallel to the longitudinal direction X, and the direction intersecting the longitudinal direction X becomes a direction, and the shape of the ridge portion 121 collapses, and the hollow structure or the like may not be maintained. In contrast, as described above, by establishing the size relationship of the "absorber non-disposed region 5N < absorber disposed region" with respect to the expansion and contraction ratio of the expansion and contraction member of the composite expansion and contraction portion 10E, the occurrence of such a problem can be prevented, and the predetermined effect of the present invention can be more reliably achieved.
The "expansion ratio" is an index of the degree of tension of the expansion member (elastic member, expansion piece, etc.) of the composite expansion portion 10E, and is a value indicating how much the expansion is performed, assuming that the length of the expansion member in the natural state (non-expanded state) is 100. The elongation ratio was measured by the following method.
First, an absorbent article (for example, diaper 1) including a stretchable member (for example, elastic member 7) to be measured is brought into a state of maximum extension in the stretchable direction (for example, transverse direction Y) of the stretchable member, and 2 marks are marked on the stretchable member with an oil pen at a predetermined interval L0 (for example, 100 mm) in the stretchable direction. In the case where the stretchable member is covered with a sheet of nonwoven fabric or the like, the stretchable member may be marked with marks via the sheet by using an oil pen, and by marking in this way, the ink of the oil pen is transferred to the stretchable member via the sheet, and marks can be marked on the stretchable member. Next, a portion sandwiched by the 2 marks was cut out from the stretchable member, and the length L1 of the cut stretchable member in a natural state (non-stretched state) was measured. The elongation ratio was obtained by the following formula [ 1 ].
Extension ratio (%) = (L0/L1) ×l00 … [ 1 ]
In the present embodiment, as described above, when the composite stretch unit 10E includes the outer layer sheet 11 (the stretch sheet 20) and the elastic member 7 as the stretch members, the above-described magnitude relation may be established between the expansion ratios of a part of the plurality of types of stretch members, or between the expansion ratios of all of the plurality of types of stretch members, in the case where the composite stretch unit 10E includes a plurality of types of stretch members. In particular, since the expansion and contraction characteristics of the elastic member 7 have a large influence on the formation of the raised strip 121, at least the expansion and contraction ratio of the elastic member 7 is set to the above-described magnitude relationship.
In view of more reliably exerting the effect of the magnitude relation of the expansion and contraction ratio of the expansion and contraction member of the composite expansion and contraction section 10E, the portion of the composite expansion and contraction section 10E located in the absorber non-placement region 5N is preferably lower in elongation stress than the portion of the composite expansion and contraction section 10E located in the absorber placement region.
The "elongation stress" is a load required to elongate the portion of the composite expansion and contraction portion 10E by a certain length in the expansion and contraction direction (transverse direction Y), and the larger the value of the elongation stress, the more difficult the portion is to elongate. Elongation stress was measured by the following method.
The extension stress of the composite expansion and contraction portion 10E can be adjusted by appropriately adjusting the type of expansion and contraction members (expansion and contraction pieces, elastic members, and the like) included in the composite expansion and contraction portion 10E, and the arrangement of the expansion and contraction members, if the expansion and contraction members are elastic members, can be adjusted by appropriately adjusting the number of the arrangement, the arrangement interval, the thickness of the elastic members, and the like.
In the present embodiment, as shown in fig. 2 and 5, the absorber non-placement region 5N includes a waist region D1 corresponding to the waist circumference of the wearer, and the absorber placement region includes an ilium region D2 corresponding to a region from the iliac crest to the anterior superior iliac spine of the wearer, and further includes a hip circumference region D3.
The absorber placement region to be compared with the absorber non-placement region 5N preferably includes at least the ilium region D2 in the magnitude relation of the expansion/contraction ratio of the expansion/contraction member of the composite expansion/contraction portion 10E and the magnitude relation of the expansion/contraction stress of the composite expansion/contraction portion 10E. That is, regarding the above-described extension ratio and extension stress, it is preferable that the size relationship of "waist region D1 (absorber non-disposed region 5N) < ilium region D2" is established.
< method of measuring elongation stress >
The case where the pants-type absorbent article to be measured is the diaper 1 will be described as an example. First, the outer body 10 joined to the side joining portion S is peeled off from each other, the diaper 1 is unfolded and spread into a planar shape, and the measurement target regions (the portions of the composite stretchable portion 10E located in the absorber non-placement region 5N and the ilium region D2, etc.) are each cut out along a straight line parallel to the lateral direction Y of the diaper 1 as measurement samples. At the time of cutting, not only the composite stretch unit 10E (outer body 10) but also the entire diaper 1 including the absorbent main body 2 and the like is cut. In the case where there is an elastic member that imparts stretchability to the composite stretch unit or a member to be treated as an elastic member (hereinafter also referred to as "elastic member or the like") such as the elastic member 7 in the measurement target region, at least 1 elastic member or the like is included in the longitudinal direction X (direction orthogonal to the extending direction of the elastic member or the like) of the measurement sample cut out from the measurement target region.
The stress (elongation stress) of the measurement sample at this time was measured by sandwiching both ends (side joining portions S or the vicinity thereof) of the measurement sample in the longitudinal direction (lateral direction Y) between chucks of a ten specimen universal tester (RTC-1210A) manufactured by orintec corporation and elongating the measurement sample in the longitudinal direction at a speed of 300 mm/min. Specifically, when the inner dimension of the composite stretchable portion 10E, more specifically, the length between the pair of side seals S, S in a state where the sheets 11 and 12 constituting the composite stretchable portion 10E are not contracted by the elastic member 7 is set to 100 (for example, 350 mm), the measurement sample is stretched to a length corresponding to 80 (for example, 280 mm), and then contracted to a length corresponding to 71 (for example, 250 mm), and the tensile load (cN) at this time is set as the stretching stress of the measurement sample. The elongation stress of the measurement sample is calculated as an average elongation stress per unit length converted into a direction (longitudinal direction X) orthogonal to the tensile direction (longitudinal direction of the measurement sample) of the measurement target region.
As described above, the reason why the restoring force at the length corresponding to 71 when the inside dimension of the outer body is 100 is defined as the stress of the measurement sample is that the ratio of the length of the main child's abdomen circumference to the inside dimension of the diaper is about 71% when the pants-type absorbent article like the diaper 1 is worn. The length of the abdominal circumference is an average value of the abdominal circumferences measured in the standing position and the sitting position, taking into consideration the change in the circumference of the abdominal circumference when the posture of the child is changed.
The ratio of the expansion member (the elastic member 7 or the outer sheet 11) located in the absorber non-disposed region 5N (the waist region D1) in the composite expansion and contraction portion 10E to the expansion ratio of the expansion member located in the absorber disposed region (the ilium region D2) in the composite expansion and contraction portion 10E is preferably 0.3 or more, more preferably 0.5 or more, and preferably 0.9 or less, and even more preferably 0.8 or less, on the premise of the former and the latter, as described above.
The expansion ratio of the expansion member in the portion of the composite expansion and contraction portion 10E located in the absorber non-placement region 5N (waist region D1) is preferably 150% or more, more preferably 200% or more, and preferably 300% or less, more preferably 250% or less, on the premise that the expansion ratio of the expansion member in the portion of the composite expansion and contraction portion 10E located in the absorber placement region (ilium region D2) is lower than that.
The expansion ratio of the expansion member in the portion of the composite expansion and contraction portion 10E located in the absorber placement region (ilium region D2) is preferably 200% or more, more preferably 250% or more, and preferably 400% or less, more preferably 350% or less, on the premise that the expansion ratio of the expansion member in the portion of the composite expansion and contraction portion 10E located in the absorber non-placement region 5N (waist region D1) is higher than that.
The ratio of the elongation stress at the portion of the composite expansion/contraction portion 10E located in the absorber non-placement region 5N (waist region D1) to the elongation stress at the portion of the composite expansion/contraction portion 10E located in the absorber placement region (ilium region D2) is preferably 0.3 or more, more preferably 0.5 or more, and preferably 0.9 or less, more preferably 0.8 or less, on the premise of the former being the former/latter, as described above.
The elongation stress of the portion of the composite expansion and contraction part 10E located in the absorber non-placement region 5N (waist region D1) is preferably 0.01N/mm or more, more preferably 0.02N/mm or more, and preferably 0.1N/mm or less, more preferably 0.05N/mm or less, on the premise that the elongation stress of the portion of the composite expansion and contraction part 10E located in the absorber placement region (ilium region D2) is lower than that.
The elongation stress of the portion of the composite expansion and contraction part 10E located in the absorber placement region (ilium region D2) is preferably 0.02N/mm or more, more preferably 0.04N/mm or more, and preferably 0.2N/mm or less, more preferably 0.1/mm or less, on the premise that the elongation stress of the portion of the composite expansion and contraction part 10E located in the absorber non-placement region 5N (waist region D1) is higher than that.
In the outer package folded-back portion 14, as shown in fig. 7 and 8, it is preferable that the concave portion 120 on the outer surface side 14a (the composite stretch portion 10E on the outer side in the thickness direction of the outer package folded-back portion 14) is opposed to the concave portion 120 on the inner surface side 14b (the folded-back composite stretch portion 10E on the inner side in the thickness direction of the outer package folded-back portion 14). With this structure, the cushioning properties of the outer body folded-back portion 14 are further improved, and for example, when a load is applied to the outer body folded-back portion 14 in a sleeping position of the wearer of the diaper 1, a good cushioning feel can be obtained.
From the same point of view, as shown in fig. 7 and 8, in the outer body folded-back portion 14, it is preferable that the convex portion 121 on the outer surface side 14a (the composite expansion and contraction portion 10E on the outer side in the thickness direction of the outer body folded-back portion 14) is opposed to the convex portion 121 on the inner surface side 14b (the folded-back composite expansion and contraction portion 10E on the inner side in the thickness direction of the outer body folded-back portion 14).
As shown in the drawing, in the outer body folded-back portion 14, it is preferable that the convex portion 121 on the outer surface side 14a (one of the opposing composite elastic members 10E, 10E) and the convex portion 121 on the inner surface side 14b (the other of the opposing composite elastic members 10E, 10E) are bonded to each other, and the folded-back composite elastic member 10E is bonded to each other. In the illustrated embodiment, the tops (bent portions 12P) of the ridge portions 121 are joined to each other via the adhesive portion 15. The adhesive portion 15 is formed by applying an adhesive such as a hot melt adhesive.
The adhesive portion 15 preferably extends in the longitudinal direction X from the viewpoint of further improving the cushioning property of the outer package folded-back portion 14, and the like. The term "extending in the longitudinal direction X" as used herein includes: 1) The plurality of bonding portions 15 are arranged at intervals in the longitudinal direction X, and form rows of bonding portions 15 extending in the longitudinal direction X; and 2) the adhesive portion 15 has a continuous linear shape (linear shape, curved shape, etc.) in a plan view.
Fig. 10 shows an exterior body folded-back portion 14A as another embodiment of the exterior body folded-back portion of the present invention. The outer body folded-back portion 14A will mainly be described in a configuration different from that of the outer body folded-back portion 14 (see fig. 7), and the same reference numerals are given to the same configuration, and the description thereof will be omitted. The configuration of the outer package folded-back portion 14A is not particularly described, and the description of the outer package folded-back portion 14 can be used as appropriate.
The pattern of the ridge 121 is different between the composite stretch unit 10E on the outer surface side 14A (the composite stretch unit 10E on the outer side in the thickness direction of the outer body folded-back unit 14A) and the inner surface side 14b (the folded-back composite stretch unit 10E on the inner side in the thickness direction of the outer body folded-back unit 14A) in the outer body folded-back unit 14A. The term "pattern of the ridge 121" as used herein refers to a concept including a pitch of the ridge 121 (a distance between top portions of the ridge 121 and the ridge 121 adjacent to each other in the lateral direction Y), a width of the ridge 121 (a length of the ridge 121 in a direction (lateral direction Y) orthogonal to the extending direction (longitudinal direction X) of the ridge 121), and a height of the ridge 121, and the pattern of the ridge 121 is different between the outer surface side 14a and the inner surface side 14b even if 1 of the two is different between the two 14a and 14 b.
In the outer package folded- back portion 14A, 3 raised portions 121 on the inner surface side 14b are provided with respect to 2 raised portions 121 adjacent to each other in the lateral direction Y on the outer surface side 14A, and the width of the raised portions 121 on the inner surface side 14b is short. The height of the ridge 121 on the inner surface side 14b is low. In the outer body folded-back portion 14A, when the ridge 121 is smaller than the outer surface side 14A, which is the portion of the inner surface side 14b that is in contact with the skin of the wearer of the pants-type absorbent article, the smaller the ridge 121 is, the more easily the composite stretchable portion 10E becomes flat, so that the inner surface side 14b can be in contact with the skin of the wearer in a flat state with less irregularities. This can suppress friction of the skin of the wearer caused by the outer body folded-back portion 14A, and reduce skin problems caused by this.
In the present invention, the inner surface side 14b is larger than the outer surface side 14A in comparison with the outer body folded-back portion 14A, and the advantage of this embodiment is that the breathability of the inner surface side 14b, which is closer to the skin of the wearer, is improved.
The pattern (pitch, width, height) of the ridge portion 121 is determined by the type and arrangement of the expansion and contraction members (expansion and contraction sheets, elastic members, etc.) included in the composite expansion and contraction portion 10E, the pattern of the joint portion 13 (the interval between the joint portions, the length of the joint portion in the lateral direction Y) of the overlapped sheets 12, 13 constituting the composite expansion and contraction portion 10E, and the like, and therefore, by making these factors different on the outer surface side 14a and the inner surface side 14b, the patterns of the ridge portions 121 can be made different from each other.
The pants-type absorbent article of the present invention is applicable not only to disposable diapers but also to absorbent articles having a pants-type structure such as disposable pants and pants-type sanitary napkins, and may be articles for infants or adult.
The present invention has been described based on the embodiments, but the present invention is not limited to the embodiments described above and can be modified as appropriate.
For example, in the diaper 1, as shown in fig. 2, the outer body 10 is formed in a continuous shape extending over the abdomen-side portion a, the crotch portion B, and the back-side portion C, but instead of this shape, the outer body 10 may be divided into a abdomen-side sheet member and a back-side sheet member, and the absorbent main body 2 may be stretched and fixed to both sheet members.
In addition, only the portions of the above-described embodiment can be fully utilized as appropriate. The following supplementary notes are further disclosed with respect to the embodiments of the present invention described above.
<1>
A pants-type absorbent article having a longitudinal direction extending from the abdomen side of a wearer to the back side via a crotch portion and a transverse direction orthogonal to the longitudinal direction, the pants-type absorbent article being divided into a crotch portion disposed in the crotch portion of the wearer, an abdomen side portion disposed closer to the abdomen side of the wearer than the crotch portion, and a back side portion disposed closer to the back side of the wearer than the crotch portion, and having an absorbent body including an absorber, and an outer body disposed on a non-skin-facing surface side of the absorbent body,
The side portions and the back portion are joined to each other at both side edges of the outer body along the longitudinal direction, a waist opening and a pair of leg openings are formed, and in the pants-type absorbent article,
the outer cover includes an outer sheet disposed at a relatively distant position from the absorber, and an inner sheet disposed at a relatively close position from the absorber,
at least a part of the outer body is a composite stretchable portion having stretchability in the lateral direction, in which the outer layer sheet and the inner layer sheet are joined by a plurality of joining portions arranged at intervals in the lateral direction,
in the composite stretch unit in a natural state, the inner sheet has a pleated structure including a plurality of concave portions extending in the longitudinal direction and having the joint portion at a bottom portion thereof, and convex portions located between the concave portions and having a curved portion of the inner sheet as a top portion, the outer sheet has a plurality of curved portions in a region overlapping with 1 of the convex portions of the inner sheet in a plan view,
at least one of the abdomen side portion and the back side portion is provided with an outer body folded-back portion including a portion of the composite stretch unit folded back so that the inner layer sheet is folded back inside.
<2>
The pants-type absorbent article according to <1>, wherein,
in the composite expansion/contraction section in a natural state, there are 2 or more and 10 or less bending sections between the adjacent joint sections, preferably 2 or more and 5 or less.
<3>
The pants-type absorbent article according to <2> above, wherein,
the distance between the adjacent joint portions is 2mm to 15mm, preferably 3mm to 10 mm.
<4>
The pant-type absorbent article according to any of claims <1> to <3>, wherein,
the outer cover folded portion is disposed in a waist region including a longitudinal end of the pants-type absorbent article.
<5>
The pant-type absorbent article according to any of claims <1> to <4>, wherein,
when the composite stretch unit is compressed in the thickness direction, the outer layer sheet has a higher reduction rate in thickness than the inner layer sheet.
<6>
The pant-type absorbent article according to any of claims <1> to <5>, wherein,
the outer layer sheet has stretchability in the transverse direction, and the inner layer sheet does not have stretchability.
<7>
The pant-type absorbent article according to any of claims <1> to <6>, wherein,
the joint portion is constituted by a welded portion of the outer layer sheet and the inner layer sheet.
<8>
The pant-type absorbent article according to any of claims <1> to <7>, wherein,
the inner sheet has higher rigidity than the outer sheet.
<9>
The pants-type absorbent article according to <8>, wherein,
the ratio of the rigidity of the inner layer sheet to the rigidity of the outer layer sheet is 1.1 to 3.0, preferably 1.2 to 2.0.
<10>
The pant-type absorbent article according to any of the above items <1> to <9>, wherein,
the composite stretchable portion includes, as a stretchable member for imparting stretchability to the composite stretchable portion, an elastic member disposed between the outer layer sheet and the inner layer sheet so as to be stretchable in the lateral direction.
<11>
The pant-type absorbent article according to any of the above items <1> to <10>, wherein,
at least one of the abdomen side portion and the back side portion, wherein a longitudinal end of the absorber is located inside the longitudinal direction of the pants-type absorbent article, a region sandwiched between both longitudinal ends is an absorber non-placement region,
the portion of the composite stretchable portion located in the absorber non-placement region has a lower expansion ratio of the stretchable member that imparts stretchability to the composite stretchable portion than the portion of the composite stretchable portion located in the absorber placement region adjacent to the absorber non-placement region in the longitudinal direction.
<12>
The pants-type absorbent article according to <11>, wherein,
the portion of the composite stretch unit located in the absorber non-placement region has lower elongation stress than the portion of the composite stretch unit located in the absorber placement region.
<13>
The pants-type absorbent article according to <11> or <12>, wherein,
the absorber non-placement region includes a waist region corresponding to a waist circumference of a wearer, and the absorber placement region includes an ilium region corresponding to a portion from an iliac crest to a front superior iliac crest of the wearer.
<14>
The pant-type absorbent article according to any of the above items <1> to <13>, wherein,
in the outer package folded-back portion, the pattern of the convex strip portion of the composite expansion and contraction portion located on the outer side in the thickness direction is different from the pattern of the convex strip portion of the folded-back composite expansion and contraction portion located on the inner side in the thickness direction.
<15>
The pant-type absorbent article according to any of the above items <1> to <14>, wherein,
in the outer package folding-back portion, the concave portion of the composite expansion and contraction portion located on the outer side in the thickness direction and the concave portion of the folded-back composite expansion and contraction portion located on the inner side in the thickness direction face each other.
<16>
The pant-type absorbent article according to any of the above items <1> to <15>, wherein,
in the outer package folded-back portion, the convex portion of the composite expansion and contraction portion located on the outer side in the thickness direction is opposed to the convex portion of the folded-back composite expansion and contraction portion located on the inner side in the thickness direction.
<17>
The pants-type absorbent article according to <16> above, wherein,
in the outer package folded-back portion, the convex strip portion of one of the opposing composite expansion and contraction portions and the convex strip portion of the other composite expansion and contraction portion are bonded.
<18>
The pants-type absorbent article according to <17> above, wherein,
the bonding portions of the opposing raised strips extend in the longitudinal direction.
<19>
The pant-type absorbent article according to any of the above items <1> to <18>, wherein,
the engagement portion extends in the longitudinal direction.
<20>
The pant-type absorbent article according to any of the above items <1> to <19>, wherein,
the external layer sheet has a gram weight of 20g/m 2 Above and 60g/m 2 Hereinafter, it is preferably 30g/m 2 Above and 55g/m 2 The following is given.
<21>
The pant-type absorbent article according to any of the above items <1> to <20>, wherein,
the internal layer sheet had a gram weight of 13g/m 2 Above and 30g/m 2 Hereinafter, it is preferably 15g/m 2 Above and 25g/m 2 The following is given.
Industrial applicability
According to the present invention, a pants-type absorbent article having an outer covering excellent in cushioning properties and breathability, and being less likely to cause skin marks and to be less likely to be stuffy even in a wearer who is asleep can be provided.

Claims (21)

1. A pants-type absorbent article having a longitudinal direction extending from the abdomen side of a wearer to the back side via a crotch portion and a transverse direction orthogonal to the longitudinal direction, the pants-type absorbent article being divided into a crotch portion disposed in the crotch portion of the wearer, an abdomen side portion disposed closer to the abdomen side of the wearer than the crotch portion, and a back side portion disposed closer to the back side of the wearer than the crotch portion, and having an absorbent body including an absorber, and an outer body disposed on a non-skin-facing surface side of the absorbent body,
the side portions and the back portion of the outer body are joined to each other at both side edges thereof in the longitudinal direction, and a waist opening and a pair of leg openings are formed, and the pants-type absorbent article is characterized in that:
the outer body includes an outer sheet disposed at a relatively distant position from the absorbent body, and an inner sheet disposed at a relatively close position from the absorbent body,
At least a part of the outer body is a composite stretchable portion having stretchability in the lateral direction, in which the outer layer sheet and the inner layer sheet are joined by a plurality of joining portions arranged at intervals in the lateral direction,
in the composite stretch unit in a natural state, the inner sheet has a pleated structure composed of a plurality of concave strip portions having the joint portions at a bottom and extending in the longitudinal direction, and convex strip portions located between the concave strip portions and having the curved portions of the inner sheet as tops, the outer sheet has a plurality of curved portions in a region overlapping with 1 of the convex strip portions of the inner sheet in a plan view,
at least one of the abdomen side portion and the back side portion is provided with an outer body folded-back portion including a portion of the composite stretch unit folded back so that the inner layer sheet is folded back inside.
2. The pant-type absorbent article of claim 1, wherein:
in the composite expansion and contraction part in a natural state, there are 2 or more and 10 or less of the bending parts between the adjacent joint parts.
3. The pant-type absorbent article of claim 2, wherein:
The interval between the adjacent joint parts is more than 2mm and less than 15 mm.
4. A pant-type absorbent article according to any of claims 1 to 3, wherein:
the outer cover folded-back portion is disposed in a waist region including a longitudinal end of the pants-type absorbent article.
5. The pant-type absorbent article according to any of claims 1 to 4, wherein:
when the composite expansion and contraction part is compressed in the thickness direction, the outer layer sheet has a higher reduction rate in thickness than the inner layer sheet.
6. The pant-type absorbent article according to any of claims 1 to 5, wherein:
the outer layer sheet has stretchability in the transverse direction, and the inner layer sheet does not have stretchability.
7. The pant-type absorbent article according to any of claims 1 to 6, wherein:
the joint is formed by a welded portion of the outer layer sheet and the inner layer sheet.
8. The pant-type absorbent article according to any of claims 1 to 7, wherein:
the inner sheet has higher rigidity than the outer sheet.
9. The pant-type absorbent article of claim 8, wherein:
the ratio of the rigidity of the inner layer sheet to the rigidity of the outer layer sheet is 1.1 to 3.0.
10. The pant-type absorbent article according to any of claims 1 to 9, wherein:
the composite stretchable portion includes, as a stretchable member for imparting stretchability to the composite stretchable portion, an elastic member disposed between the outer layer sheet and the inner layer sheet so as to be stretchable in the lateral direction.
11. The pant-type absorbent article according to any of claims 1 to 10, wherein:
at least one of the abdomen side portion and the back side portion, the longitudinal end of the absorber is located inside the longitudinal direction of the pants-type absorbent article, a region sandwiched between both longitudinal ends becomes an absorber non-placement region,
the portion of the composite stretchable portion located in the absorber non-placement region has a lower expansion ratio of the stretchable member that imparts stretchability to the composite stretchable portion than the portion of the composite stretchable portion located in the absorber placement region adjacent to the absorber non-placement region in the longitudinal direction.
12. The pant-type absorbent article of claim 11, wherein:
the portion of the composite expansion and contraction portion located in the absorber non-placement region has lower elongation stress than the portion of the composite expansion and contraction portion located in the absorber placement region.
13. The pant-type absorbent article of claim 11 or 12, wherein:
the absorber non-deployment region includes a waist region corresponding to a waist circumference of a wearer, and the absorber deployment region includes an ilium region corresponding to a portion from an iliac crest to a anterior superior iliac spine of the wearer.
14. The pant-type absorbent article according to any of claims 1 to 13, wherein:
in the outer package folded-back portion, the pattern of the convex strip portion of the composite stretchable portion located on the outer side in the thickness direction is different from the pattern of the convex strip portion of the folded-back composite stretchable portion located on the inner side in the thickness direction.
15. The pant-type absorbent article according to any of claims 1 to 14, wherein:
in the outer package folded-back portion, the concave portion of the composite expansion and contraction portion located on the outer side in the thickness direction is opposed to the concave portion of the folded-back composite expansion and contraction portion located on the inner side in the thickness direction.
16. The pant-type absorbent article according to any of claims 1 to 15, wherein:
in the outer package folded-back portion, the convex strip portion of the composite expansion and contraction portion located on the outer side in the thickness direction is opposed to the convex strip portion of the folded-back composite expansion and contraction portion located on the inner side in the thickness direction.
17. The pant-type absorbent article of claim 16, wherein:
in the outer package folded-back portion, the convex strip portion of one of the opposing composite expansion and contraction portions and the convex strip portion of the other composite expansion and contraction portion are bonded.
18. The pant-type absorbent article of claim 17, wherein:
the bonding portions of the opposing raised strips extend in the longitudinal direction.
19. The pant-type absorbent article according to any of claims 1 to 18, wherein:
the engagement portion extends in the longitudinal direction.
20. The pant-type absorbent article according to any of claims 1 to 19, wherein:
the external layer sheet has a gram weight of 20g/m 2 Above and 60g/m 2 The following is given.
21. The pant-type absorbent article according to any of claims 1 to 20, wherein:
the internal layer sheet has a gram weight of 13g/m 2 Above and 30g/m 2 The following is given.
CN202180061748.0A 2020-09-08 2021-09-08 Pants-type absorbent article Pending CN116056675A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2020-150825 2020-09-08
JP2020150825 2020-09-08
JP2021146050A JP7037693B1 (en) 2020-09-08 2021-09-08 Pants type absorbent article
JP2021-146050 2021-09-08
PCT/JP2021/033016 WO2022054832A1 (en) 2020-09-08 2021-09-08 Underpants-type absorbent article

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JP4205385B2 (en) * 2002-08-30 2009-01-07 ユニ・チャーム株式会社 Disposable wearing items
JP5929984B2 (en) * 2014-08-20 2016-06-08 王子ホールディングス株式会社 Disposable diapers and cushion sheets
JP6425624B2 (en) * 2015-06-26 2018-11-21 ユニ・チャーム株式会社 Disposable Wearables
JP6855944B2 (en) * 2016-08-08 2021-04-07 王子ホールディングス株式会社 Absorbent article
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