CN112004507B - Absorbent article - Google Patents

Absorbent article Download PDF

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Publication number
CN112004507B
CN112004507B CN201980027659.7A CN201980027659A CN112004507B CN 112004507 B CN112004507 B CN 112004507B CN 201980027659 A CN201980027659 A CN 201980027659A CN 112004507 B CN112004507 B CN 112004507B
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CN
China
Prior art keywords
skin
sheet
sheet portion
waist
waistline
Prior art date
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Active
Application number
CN201980027659.7A
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Chinese (zh)
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CN112004507A (en
Inventor
井上拓也
槙秀晃
清水纪子
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Unicharm Corp
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Unicharm Corp
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Filing date
Publication date
Priority claimed from JP2018083373A external-priority patent/JP7048401B2/en
Priority claimed from JP2018083372A external-priority patent/JP7054643B2/en
Application filed by Unicharm Corp filed Critical Unicharm Corp
Publication of CN112004507A publication Critical patent/CN112004507A/en
Application granted granted Critical
Publication of CN112004507B publication Critical patent/CN112004507B/en
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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

Abstract

The absorbent article has: an absorbent main body (10) provided with an absorbent core (11A); and a pair of waist parts (20). The waist body part (20) is provided with a skin side sheet part (221) positioned closest to the skin and a plurality of elastic threads (23) capable of stretching in the transverse direction. In the waist part (20), the bending rigidity of the skin side panel part (221) measured by the KES method is 0.0096 N.m 2 /m×10 ‑4 Thereafter, the inner layer panel portion (21) is disposed between the skin side panel portion (221) and the elastic thread (23) in the thickness direction of the waistline portion (20) and is located on the waistline side of the absorbent main body (10) in the longitudinal direction. The bending rigidity of the inner sheet portion (21) measured by the KES method is greater than the bending rigidity of the skin-side sheet portion (221).

Description

Absorbent article
Technical Field
The present invention relates to an absorbent article.
Background
Patent document 1 discloses an absorbent article including an absorbent main body (main body) including a liquid-permeable front sheet, a liquid-impermeable back side sheet, and an absorbent body between the front sheet and the back side sheet, and an exterior sheet covering the back side of the absorbent main body. Further, patent document 1 discloses that the flexibility of the outermost nonwoven fabric of the outer sheet significantly affects the flexibility of the entire absorbent article, and discloses that the outermost nonwoven fabric is a soft nonwoven fabric having a bending degree of 3.8gf cm/cm or less.
Further, patent document 1 describes that, similarly to the outermost nonwoven fabric, it is desirable to use a soft nonwoven fabric for all the nonwoven fabrics constituting the exterior sheet, that is, for the front and rear pressure-applying sheets covering the front and rear end portions of the absorbent main body and for the upper layer nonwoven fabric sandwiching the elastic threads together with the outermost nonwoven fabric. Patent document 1 also discloses that front and rear pressing sheets are formed by extending the inner surface folded portion of the soft outermost nonwoven fabric until the portion overlaps with the front and rear end portions of the absorbent main body.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2010-131167
Disclosure of Invention
Problems to be solved by the invention
The problem to be solved by the present invention is at least one of the first and second problems described below.
A first problem is that, in the above case, the material arranged on the skin side with respect to the elastic threads is only a soft nonwoven fabric. In this case, the linear load of the elastic threads is less likely to be absorbed and relaxed by the nonwoven fabric on the skin side, and the elastic threads are fixed to the skin of the wearer, while the nonwoven fabric adheres around the elastic threads. Therefore, a linear load of the elastic threads may be applied to the wearer's skin, and traces of the elastic threads may be left on the wearer's skin. In particular, in many cases, the abdomen of the wearer protrudes, and a line mark may occur on the abdomen of the wearer.
Accordingly, it is an object of the present invention to provide an absorbent article which is less likely to cause a line mark on the waistline of a wearer.
A second problem is that, in the above case, the material disposed on the skin side with respect to the waistline-side end portions (front and rear end portions) of the absorbent main body is only a soft nonwoven fabric. In the waist-side end portion of the absorbent main body, a plurality of materials are laminated on each other and coated with an adhesive. Therefore, the waistline-side end of the absorbent main body is hard, and therefore the soft nonwoven fabric is difficult to absorb and moderate the stiffness of the waistline-side end edge of the absorbent main body (i.e., the stiffness of the edge in the step between the portion having the absorbent main body and the portion not having the absorbent main body). Therefore, there is a risk that the waist-side end edge of the absorbent main body damages the skin of the wearer.
Accordingly, it is an object of the present invention to provide an absorbent article in which the waist-side end edge of the absorbent main body is less likely to damage the skin of the wearer.
Means for solving the problems
A main aspect of the present invention for solving the first problem is an absorbent article having a longitudinal direction and a transverse direction, the absorbent article comprising: an absorbent body comprising an absorbent core; and a pair of waistline portions each including a skin-side panel portion disposed at a position closest to the skin side and a plurality of elastic threads stretchable in the transverse direction, the skin-side panel portion having a flexural rigidity of 0.0096N-m based on the KES method in at least one of the pair of waistline portions 2 /m×10 -4 Hereinafter, the waist portion has an inner sheet portion located on the waist side with respect to the absorbent main body in the longitudinal direction, the inner sheet portion is located between the skin side sheet portion and the elastic thread in the thickness direction of the waist portion, and the flexural rigidity of the inner sheet portion based on the KES method is higher than the flexural rigidity of the skin side sheet portion.
A main aspect of the present invention for solving the second problem is an absorbent article having a longitudinal direction and a transverse direction, the absorbent article comprising: an absorbent body comprising an absorbent core; and a pair of waistline portions each including a skin-side panel portion disposed at a position closest to the skin side, the skin-side panel portion having a flexural rigidity of 0.0096N · m based on a KES method in at least one of the pair of waistline portions 2 /m×10 -4 Hereinafter, an inner sheet is disposed on the non-skin side with respect to the skin-side sheet, andthe inner sheet portion has a flexural rigidity based on the KES method higher than that of the skin-side sheet portion, and is disposed on the skin side of the absorbent main body and spans the waist-side end edge of the absorbent main body in the longitudinal direction.
Other features of the present invention will become apparent by reading the description of the present specification with reference to the accompanying drawings.
ADVANTAGEOUS EFFECTS OF INVENTION
Regarding the first problem, the effect of the present invention is to provide an absorbent article that is less likely to cause a line mark on the waistline of the wearer.
Regarding the second problem, the present invention has an effect of providing an absorbent article in which the waist-side end edge of the absorbent main body is less likely to damage the skin of the wearer.
Drawings
Fig. 1 is a perspective view of a pants-type disposable diaper 1.
Fig. 2 is a plan view of the diaper 1 in a developed state and in an extended state.
Fig. 3 is a sectional view taken along line I-I in fig. 2.
Fig. 4A is a schematic cross-sectional view of the waistline portion 40 taken in the thickness direction according to the comparative example, and fig. 4B is a schematic cross-sectional view of the waistline portion 20 taken in the thickness direction according to the embodiment.
Fig. 5 is an enlarged sectional view of the abdomen-side waistline portion 20 shown in fig. 3.
Fig. 6 is a sectional view of a modification of the waistline unit 20.
Fig. 7 is a sectional view of a modification of the waistline unit 20.
Fig. 8 is a sectional view of a modification of the waistline unit 20.
Fig. 9 is a sectional view of a modification of the waistline unit 20.
Fig. 10 is a perspective view of a pants-type disposable diaper 1 according to a second embodiment.
Fig. 11 is a plan view of the diaper 1 in an unfolded and extended state.
Fig. 12 is a sectional view taken along line I-I in fig. 11.
Fig. 13A is a schematic sectional view illustrating a contracted state of the skin-side sheet portion 40 according to the comparative example, and fig. 13B is a schematic sectional view illustrating a contracted state of the skin-side sheet portion 221 according to the embodiment.
Fig. 14 is an enlarged view of a sectional view of the abdominal-side waistline unit 20 shown in fig. 12.
Fig. 15 is a sectional view of a modification of the waistline unit 20.
Fig. 16 is a sectional view of a modification of the waistline unit 20.
Fig. 17 is a sectional view of a modification of the waistline unit 20.
Detailed Description
At least the following matters will become clear from the description of the present specification and the accompanying drawings.
An absorbent article having a longitudinal direction and a transverse direction, the absorbent article comprising: an absorbent body comprising an absorbent core; and a pair of waistline portions each including a skin-side panel portion disposed at a position closest to the skin side and a plurality of elastic threads stretchable in the transverse direction, the skin-side panel portion having a flexural rigidity of 0.0096N-m based on the KES method in at least one of the pair of waistline portions 2 /m×10 -4 Hereinafter, the waist portion has an inner sheet portion located on the waist side with respect to the absorbent main body in the longitudinal direction, the inner sheet portion is located between the skin side sheet portion and the elastic thread in the thickness direction of the waist portion, and the flexural rigidity of the inner sheet portion based on the KES method is higher than the flexural rigidity of the skin side sheet portion.
According to such an absorbent article, the flexural rigidity of the skin-side sheet portion is low. Therefore, the irregularities formed on the waist portion due to the contraction of the elastic threads are easily crushed, so that wrinkles are hardly generated on the waist of the wearer. Further, since the linear load of the elastic thread is absorbed and relaxed by the inner layer panel portion, the thread mark is less likely to be generated on the waistline of the wearer.
In such an absorbent article, the waist portion includes a non-skin side panel portion disposed at a position closest to a non-skin side, the elastic thread is disposed between the inner layer panel portion and the non-skin side panel portion in the thickness direction, and the skin side panel portion is a portion formed by folding a waist-side end portion of the non-skin side panel portion in the longitudinal direction toward a skin side.
According to such an absorbent article, the flexural rigidity of the non-skin side panel portion is low, similar to the flexural rigidity of the skin side panel portion, so that the feeling of the waist portion from the non-skin side can be improved.
In such an absorbent article, the waist-side end portion in the longitudinal direction of the inner layer panel portion is folded toward the skin side.
According to such an absorbent article, since the inner sheet portion disposed on the skin side with respect to the elastic thread is formed in two layers, it is less likely that a line mark will be generated on the waistline of the wearer.
In such an absorbent article, the waist portion includes a second inner sheet portion disposed on the non-skin side with respect to the inner sheet portion, and a non-skin side sheet portion disposed at a position closest to the non-skin side, and the second inner sheet portion has a flexural rigidity according to the KES method of 0.0096N · m 2 /m×10 -4 Hereinafter, the elastic thread is arranged between the second inner-layer panel portion and the non-skin-side panel portion in the thickness direction, and the skin-side panel portion is a portion formed by folding a waistline-side end portion of the non-skin-side panel portion in the longitudinal direction toward a skin side.
According to such an absorbent article, even when the flexural rigidity of the second inner layer panel portion is low, since the linear load of the elastic thread is absorbed and relaxed by the inner layer panel portion, it is less likely that a line mark will be generated at the waistline of the wearer.
In such an absorbent article, the waistline portion includes a third inner-layer panel portion and a non-skin-side panel portion, the third inner layer sheet portion is disposed on a non-skin side with respect to the inner layer sheet portion, the non-skin side sheet portion being disposed at a position closest to the non-skin side, the waist portion has a waist side portion and a core side portion, the waist side portion being a portion located on the waist side in the longitudinal direction with respect to the absorbent main body, the core side portion is a portion overlapping the absorbent core in the thickness direction, the plurality of elastic strands includes waist-side elastic strands arranged at the waist side portion and core-side elastic strands arranged at the core side portion, the waistline-side elastic thread is disposed between the inner sheet portion and the third inner sheet portion in the thickness direction, and the core-side elastic thread is disposed between the third inner-layer sheet portion and the non-skin-side sheet portion in the thickness direction.
According to such an absorbent article, it is less likely that the waistline-side elastic threads will be recognized from the non-skin-side, so that the impression that the waistline-side portion has a soft fit can be given to the user. On the other hand, the core-side elastic threads are easily visually recognized from the non-skin side, so that the user can be given the impression that the absorbent core has high fit and less leakage.
In such an absorbent article, the waist portion has an intermediate portion between the waist side portion and the core side portion in the longitudinal direction, the plurality of elastic threads includes intermediate elastic threads disposed in the intermediate portion, and some of the intermediate elastic threads are disposed at a position between the inner sheet portion and the third inner sheet portion in the thickness direction, and some of the intermediate elastic threads are disposed at a position between the third inner sheet portion and the non-skin side sheet portion in the thickness direction.
According to such an absorbent article, the stretching force of the intermediate portion can be increased, so that sagging of the absorbent main body can be suppressed.
In such an absorbent article, the waist portion has a waist side portion and an absorbent body side portion, the waist side portion is a portion located on the waist side in the longitudinal direction with respect to the absorbent body, the absorbent body side portion is a portion overlapping with the absorbent body in the thickness direction, and a value obtained by dividing a magnitude of a force by which the waist side portion is elongated in the transverse direction by a unit length is smaller than a value obtained by dividing a magnitude of a force by which the absorbent body side portion is elongated in the transverse direction by a unit length by which the absorbent body side portion is elongated in the longitudinal direction.
According to such an absorbent article, since the stretchable force of the waist side portion is smaller than the stretchable force of the absorbent main body side portion, wrinkle marks or line marks are less likely to be generated on the waist of the wearer.
In such an absorbent article, the waist-side end of the inner sheet portion is located on the waist side in the longitudinal direction with respect to the elastic thread arranged at the position closest to the waist side among the plurality of elastic threads.
According to such an absorbent article, the inner layer sheet portion can be disposed on the skin side with respect to more elastic threads, so that it is less likely to cause a line mark on the waist of the wearer.
In such an absorbent article, the crotch side end of the inner sheet portion is located on the crotch side in the longitudinal direction with respect to the waist side end of the absorbent main body.
According to such an absorbent article, the inner sheet portion can be disposed on the skin side with respect to more elastic threads, so that it is less likely to cause a line mark on the waistline of the wearer.
In such an absorbent article, the flexural rigidity of the skin-side panel portion by the KES method is 0.0035N · m 2 /m×10 -4 The above.
According to such an absorbent article, an appropriate tensile strength of the skin side panel portion can be obtained, so that the waistline portion can be suppressed from breaking in use.
In such an absorbent article, the skin-side sheet portion has a compression recovery rate RC of 15% or more and 50% or less by the KES method.
According to such an absorbent article, the irregularities formed on the waist portion due to contraction of the elastic threads are easily crushed, and wrinkles are hardly generated on the waist of the wearer.
In such an absorbent article, the skin-side panel portion has a basis weight of 10g/m 2 Above and 30g/m 2 And the skin-side sheet portion has a load of 0.12g/cm at 49.03hPa 3 Above and 0.2g/cm 3 The following apparent density.
According to such an absorbent article, the flexural rigidity of the skin-side sheet portion can be reduced, and the flexibility thereof can be improved.
In such an absorbent article, the skin-side sheet portion contains fibers having a fiber diameter of 14 μm or more and 22 μm or less, and the coefficient of variation MMD/MIU × 100 of the friction coefficient of the skin-side sheet portion by the KES method is 2% or more and 6% or less.
According to such an absorbent article, the skin-side sheet portion has relatively many fibers, which have a small variation in the friction coefficient and come into contact with the fingertips in such a manner as to adhere to the fingertips of the user. Providing a smooth, pliable and soft feel.
In such an absorbent article, the skin-side sheet portion has a friction coefficient MIU of at least 0.25.
According to such an absorbent article, the skin-side sheet portion has a relatively large number of fibers which are brought into contact with the fingertips in such a manner as to adhere to the fingertips of the user. Providing a smooth, pliable, and soft feel.
In such an absorbent article, the skin side panel portion contains polyethylene fibers.
According to such an absorbent article, polyethylene fibers are more flexible than other thermoplastic resin fibers such as polypropylene fibers and PET (polyethylene terephthalate) fibers. Therefore, the flexural rigidity of the skin-side sheet portion can be reduced, and the flexibility thereof can be improved.
An absorbent article having a longitudinal direction and a transverse direction, the absorbent article comprising: an absorbent body including an absorbent core; and a pair of waistline portions each including a skin-side panel portion disposed at a position closest to the skin side, the skin-side panel portion having a flexural rigidity of 0.0096N · m based on a KES method in at least one of the pair of waistline portions 2 /m×10 -4 An inner sheet portion having a higher flexural rigidity by the KES method than that of the skin-side sheet portion is disposed on a non-skin side with respect to the skin-side sheet portion, and the inner sheet portion is disposed on the absorbent main bodyA skin side and spans a waist-side end edge of the absorbent main body in the longitudinal direction.
According to such an absorbent article, the flexural rigidity of the skin-side sheet portion is low. Therefore, the feeling of the wearer can be improved. Further, the irregularities formed by the contraction of the waist portion are easily crushed, so that wrinkles are hardly formed on the waist of the wearer. Further, since the hardness and the step at the end edge of the absorbent main body are absorbed and relaxed by the inner-layer sheet portion, the skin of the wearer can be prevented from being damaged by the end edge of the absorbent main body.
In such an absorbent article, the waist portion includes a non-skin-side sheet portion disposed at a position closest to a non-skin side, the skin-side sheet portion is a portion obtained by folding a waist-side end portion of the non-skin-side sheet portion in the longitudinal direction toward a skin side, the inner-layer sheet portion has a skin-side portion obtained by folding the waist-side end portion in the longitudinal direction toward a skin side, and a non-skin-side portion which is a portion disposed on a non-skin side with respect to the skin-side portion, a stretchable member is disposed between the non-skin-side portion of the inner-layer sheet portion and the non-skin-side sheet portion in a thickness direction of the waist portion, the stretchable member is stretchable in the transverse direction, and the skin-side portion of the inner-layer sheet portion is disposed on the skin side of the absorbent main body, spanning the waist-side end edges of the absorbent main body in the longitudinal direction.
According to such an absorbent article, the inner sheet portion absorbs and moderates the hardness and the step at the end edge of the absorbent main body, so that the end edge of the absorbent main body can be prevented from damaging the skin of the wearer. In addition, the flexural rigidity of the non-skin-side sheet portion is low, similarly to the skin-side sheet portion, so that the feeling of the waist portion from the non-skin side can be improved.
In such an absorbent article, the crotch-side end edge of the skin-side portion of the inner sheet portion is located on the crotch side in the longitudinal direction with respect to the waist-side end edge of the absorbent core.
According to such an absorbent article, the inner layer sheet portion absorbs and moderates the hardness and the step of the end edge of the absorbent core, so that the end edge of the absorbent core can be suppressed from damaging the skin of the wearer.
In such an absorbent article, a stretchable sheet portion is disposed between a skin side portion and a non-skin side portion of the inner sheet portion in a thickness direction of the waist portion, the stretchable sheet portion is stretchable in the transverse direction, a flexural rigidity of the stretchable sheet portion according to the KES method is higher than a flexural rigidity of the skin side sheet portion, and the stretchable sheet portion is disposed on a skin side of the absorbent main body across a waist-side end edge of the absorbent main body in the longitudinal direction.
According to such an absorbent article, the inner sheet portion and the stretchable sheet portion absorb and relax the hardness and the step at the end edge of the absorbent main body, so that the end edge of the absorbent main body can be further suppressed from damaging the skin of the wearer.
In such an absorbent article, the crotch-side end edge of the skin-side portion of the inner sheet, the crotch-side end edge of the skin-side sheet, and the crotch-side end edge of the stretchable sheet are displaced from each other in the longitudinal direction.
According to such an absorbent article, steps at the end edges of the respective sheet portions are reduced, so that the skin of the wearer can be suppressed from being damaged by the end edges of the respective sheet portions.
In such an absorbent article, the crotch-side end edge of the skin-side portion of the inner sheet portion is located on the most crotch-side position in the longitudinal direction.
According to such an absorbent article, the following phenomena can be suppressed: the skin side sheet portion having low rigidity is located at the most crotch side position, causing it to be twisted; the stretchable sheet portion is located on the crotch side, and the stretchable sheet portion is curled.
In such an absorbent article, the inner sheet portion is an extensible sheet portion extensible in the lateral direction.
According to such an absorbent article, the rigidity and the level difference of the end edges of the absorbent main body are absorbed and relaxed by the stretchable sheet portion, and the waist portion is brought into close contact with the ground of the wearer, whereby local tightening pressure can be suppressed. Therefore, the waist of the wearer can be further prevented from being damaged.
In such an absorbent article, the crotch-side end edge of the stretchable sheet portion is positioned on the waist-side end of the absorbent core in the longitudinal direction.
According to such an absorbent article, excessive contraction of the absorbent core due to the stretchable sheet section can be suppressed. The flatness of the absorbent core can be maintained.
In such an absorbent article, the skin-side sheet portion is disposed on the skin side of the absorbent main body and spans the waist-side end edge of the absorbent main body in the longitudinal direction.
According to such an absorbent article, the hardness and the step at the end edge of the absorbent main body are absorbed and alleviated by the inner layer sheet portion and the skin side sheet portion, and therefore, the skin of the wearer can be further suppressed from being damaged by the end edge of the absorbent main body.
In such an absorbent article, the flexural rigidity of the skin-side panel portion by the KES method is 0.0035N · m 2 /m×10 -4 The above.
According to such an absorbent article, appropriate tensile strength of the skin side panel portion can be obtained, so that the waist portion can be suppressed from breaking during use.
In such an absorbent article, the skin-side sheet portion has a compression recovery rate RC of 15% or more and 50% or less by the KES method.
According to such an absorbent article, the irregularities formed on the waist portion due to contraction of the elastic threads are easily crushed, and wrinkle marks are hardly generated on the waist of the wearer.
In such an absorbent article, the skin-side panel portion has a basis weight of 10g/m 2 Above and 30g/m 2 And the skin-side sheet portion has a weight of 0.12g/cm under a load of 49.03hPa 3 Above and 0.2g/cm 3 The following apparent density.
According to such an absorbent article, the flexural rigidity of the skin-side sheet portion can be reduced, and the flexibility thereof can be improved.
In such an absorbent article, the skin-side sheet portion contains fibers having a fiber diameter of 14 μm or more and 22 μm or less, and the coefficient of variation MMD/MIU × 100 of the friction coefficient of the skin-side sheet portion by the KES method is 2% or more and 6% or less.
According to such an absorbent article, the skin-side sheet portion has a large number of fibers, and these fibers have a small change in the friction coefficient and are brought into contact with the fingertips in such a manner as to adhere to the fingertips of the user. Providing a smooth, pliable and soft feel.
In such an absorbent article, the skin-side sheet portion has a friction coefficient MIU of at least 0.25.
According to such an absorbent article, the skin-side panel portion has many fibers, and these fibers are in contact with the user's fingertips so as to adhere to the fingertips. Providing a smooth, pliable and soft feel.
In such an absorbent article, the skin side panel portion contains polyethylene fibers.
According to such an absorbent article, polyethylene fibers are more flexible than other thermoplastic resin fibers such as polypropylene fibers and PET (polyethylene terephthalate) fibers. Therefore, the flexural rigidity of the skin-side sheet portion can be reduced, and the flexibility thereof can be improved.
Embodiments of the present invention are described in detail below with reference to the accompanying drawings
Hereinafter, an embodiment of the absorbent article according to the present invention will be described using a pants-type disposable diaper for infants as an example. However, the absorbent article according to the present invention is not limited to the pants-type disposable diaper for infants and can be applied to pants-type disposable diapers for adults, tape-type disposable diapers, sanitary underpants, and the like.
< first embodiment >
Disposable diaper 1 of the pants type
Fig. 1 is a perspective view of a pants-type disposable diaper 1 (hereinafter, referred to as "diaper"). Fig. 2 is a plan view of the diaper 1 in an unfolded and extended state. Fig. 3 is a sectional view taken along line I-I in fig. 2.
In the pant-type state shown in fig. 1, the diaper 1 has a longitudinal direction, a transverse direction, and a front-rear direction, and has a waist opening BH and a pair of leg openings LH. In the longitudinal direction, the waistline side is defined as the upper side, and the crotch side is defined as the lower side. In the front-rear direction, the ventral side of the wearer is defined as the front side, and the dorsal side of the wearer is defined as the rear side. As shown in fig. 3, the direction in which the materials constituting the diaper 1 are laminated with each other is the thickness direction. In the thickness direction, the side of the diaper 1 which comes into contact with the wearer is defined as the skin side, and the side of the diaper 1 which does not come into contact with the wearer is defined as the non-skin side.
The diaper 1 includes an absorbent main body 10 and a pair of waist portions 20 and 30, which are three members rectangular in plan view. Of the pair of waistline portions 20 and 30, one attached to the abdominal side portion of the wearer is the abdominal-side waistline portion 20, and the other attached to the back side portion of the wearer is the back-side waistline portion 30.
In the diaper 1 shown in fig. 2 in an unfolded state, the abdominal-side waistline portion 20 and the back-side waistline portion 30 are arranged such that the lengthwise direction of these portions extends in the transverse direction of the diaper 1. One end portion in the longitudinal direction of the absorbent main body 10 is disposed in the widthwise center portion of the abdominal-side waistline portion 20. The end portion on the other longitudinal side of the absorbent main body 10 is disposed in the lateral center portion of the back-side waistline portion 30.
In the diaper 1 in the developed state shown in fig. 2, the absorbent main body 10 is folded in half substantially at the center in the longitudinal direction in such a manner that the longitudinal direction extends along the longitudinal direction of the diaper 1. Then, in the transverse direction of the diaper 1, both side end portions of the abdomen-side waistline portion 20 and both side end portions of the back-side waistline portion 30 are joined together by welding or by using an adhesive, to form the pants-type diaper 1 shown in fig. 1.
As shown in fig. 3, the absorbent body 10 includes an absorbent body 11, a liquid-permeable top sheet 12 disposed on the skin side with respect to the absorbent body 11, a liquid-impermeable back sheet 13 disposed on the non-skin side with respect to the absorbent body 11, and an exterior sheet 14 disposed on the non-skin side with respect to the back sheet 13. The outer sheet 14 is preferably a flexible sheet.
As shown in fig. 2, the absorbent body 11 includes: an absorbent core 11A that absorbs and retains excretory fluid such as urine; a liquid-permeable core wrap sheet 11B covering the absorbent core 11A. An example of the absorbent core 111A may be one obtained by forming liquid absorbent fibers such as pulp containing a super absorbent polymer (so-called SAP) into a predetermined shape. Note that the absorbent core 11A is not limited to being covered by the core wrap sheet 11B.
As shown in fig. 2, leg elastic members 15 are provided on both lateral side portions of the absorbent main body 10. Thus, the diaper 1 fits to the legs of the wearer. The leg elastic members 15 are fixed between the two layers of exterior sheets 14 folded inward in the lateral direction in a state of being elongated in the longitudinal direction of the absorbent main body 10. Examples of the leg elastic member 15 may be an elastic thread and an elastic nonwoven fabric.
As shown in fig. 3, the abdominal-side waistline portion 20 (back-side waistline portion 30) includes a first panel 21(31), a second panel 22(32), and a plurality of elastic threads 23(33) which are stretchable in the transverse direction. A plurality of elastic strands 23(33) are arranged side by side in the longitudinal direction between the first sheet 21(31) and the second sheet 22(32) and fixed in a state of being elongated in the transverse direction. Therefore, the abdominal-side waistline portion 20 and the back-side waistline portion 30 are stretched in the lateral direction and fit to the waistline of the wearer. Suitable examples of the elastic threads 23 and 33 are styrene-based rubbers, urethane-based rubbers, ester-based rubbers, and other known synthetic rubbers made of polyurethane or polyethylene, in addition to natural rubbers in the form of threads.
In the present embodiment, as an example of a pants-type disposable diaper, a so-called three-piece type is explained in which the abdomen-side waistline portion 20 and the back-side waistline portion 30 are separated and include the abdomen-side waistline portion 20, the back-side waistline portion 30, and the absorbent main body 10. However, it is not limited thereto. For example, a so-called two-piece pants-type disposable diaper may be used which includes an absorbent main body and an exterior member in which the abdomen-side waistline portion 20 and the back-side waistline portion 30 are integrated and the abdomen-side waistline portion 20 and the back-side waistline portion 30 are continuous in the crotch portion to form one unit.
The characteristic portions of the waistline portions 20 and 30
Fig. 4A is a schematic cross-sectional view of the waistline portion 40 taken in the thickness direction according to the comparative example, and fig. 4B is a schematic cross-sectional view of the waistline portion 20 taken in the thickness direction according to the present embodiment. Fig. 5 is an enlarged view of a sectional view of the abdominal-side waistline unit 20 shown in fig. 3.
At least one of the pair of waistline portions 20, 30 included in the diaper 1 according to the present embodiment has the following characteristic features. Hereinafter, the abdomen-side waist portion 20 will be described as an example; however, the back-side waistline portion 30 does not necessarily have the following characteristic portions. Alternatively, both the abdominal-side waistline portion 20 and the back-side waistline portion 30 may have the following characteristic portions; or the back waistline portion 30 alone may have the following characteristic portions, while the abdomen waistline portion 20 does not have the following characteristic portions.
As described above, the abdominal-side waistline portion 20 (hereinafter, also simply referred to as "waistline portion 20") includes the first sheet 21, the second sheet 22, and the plurality of elastic strands 23. A part of the second sheet 22 serves as a non-skin side sheet portion 222, and the non-skin side sheet portion 222 is a portion disposed on the most non-skin side of the waistline portion 20. Another portion of the second sheet 22 serves as the skin-side sheet portion 221, and is a portion located on the skin side with respect to the absorbent main body 10 by folding the longitudinal waistline-side end portion (of the non-skin-side sheet portion 222) of the second sheet 22 toward the skin side. The plurality of elastic strands 23 are arranged between the first sheet 21 and the non-skin-side sheet portion 222 in the thickness direction.
The skin side sheet portion 221 is fixed to the first sheet 21 and the absorbent main body 10 with the adhesive 50. The longitudinal length of the skin-side sheet portion 221 is smaller than the longitudinal length of the non-skin-side sheet portion 222, and the crotch-side end portion of the skin-side sheet portion 221 can be made to cover the waist-side end portion of the absorbent main body 10. Therefore, the skin-side sheet portion 221 does not excessively cover the absorbent main body 10, which suppresses a reduction in the area that can be absorbed by the absorbent main body 10. Further, the waistline-side end portion of the absorbent main body 10 can be covered with the skin-side panel portion 221, so that the end portion of the absorbent main body 10 can be suppressed from being opened.
The first sheet 21 is disposed between the skin-side sheet portion 221 and the elastic thread 23 in the thickness direction. A part of the first sheet 21 is disposed on the waist side in the longitudinal direction with respect to the absorbent main body 10. The 1 st sheet 21 corresponds to the inner sheet portion. The first sheet 21 is fixed to the skin side sheet portion 221 and the absorbent main body 10 with the adhesive 50.
Since the skin-side sheet portion 221 is in direct contact with the skin of the wearer, a flexible sheet having low flexural rigidity is used. Therefore, the skin side panel portion 221 has a smooth, pliable and soft feel, thereby improving the feel on the skin of the wearer.
As a result of the test conducted by the inventors, it was found that the flexural rigidity of the skin-side sheet portion 221 by the KES method is preferably 0.0096N · m 2 /m×10 -4 The following. Generally, the waist portion 20 of the diaper 1 is provided with elastic threads 23 which are stretchable in the transverse direction so as to fit the waist of the wearer. The waist portion 20 is contracted in the transverse direction by the elastic threads 23, and irregularities are formed in the thickness direction, which are laterally juxtaposed in the waist portion 20. The irregularities are long in the longitudinal direction; in other words, the waistline portion 20 has a wale formed therein.
Therefore, the flexural rigidity of the skin-side sheet portion 221 is greater than 0.0096N · m 2 /m×10 -4 When the skin-side sheet portion 221 has high flexural rigidity, large and uniform irregularities are formed in the waist portion 40 due to contraction of the elastic threads 41, as in the comparative example shown in fig. 4A. Further, the shape retention (resiliency) of the protruding portion 42 protruding toward the skin side is improved. When the waist portion 40 comes into contact with the wearer, the protrusions 42 are hardly crushed, and the protrusions 42 may bite deeply into the skin of the wearer. Therefore, creases of the pleats (indentations formed by the protrusions 42) may be generated on the skin of the wearer.
In contrast, according to the present embodiment, the flexural rigidity of the skin-side sheet portion 221 is set to 0.0096N · m 2 /m×10 -4 The following. The skin-side sheet 221 is a sheet having high drapability and hanging loosely. Therefore, as shown in fig. 4B, in the waist portion 20 according to the present embodiment, uneven unevenness having repeated fine undulations is formed due to contraction of the elastic threads 23. That is, the waistline portion 20 is smooth, and the contact area between the waistline portion 20 and the skin of the wearer can be increased. Therefore, the contact pressure of the waistline portion 20 due to the elastic threads 23 can be dispersed, and thus the large protrusions 42 such as shown in fig. 4A according to the comparative example do not locally contact the wearer's skin. And, stand outThe shape retention (resilience) of the portion 26 is reduced. Therefore, when the waist portion 20 comes into contact with the wearer, the projections 26 may be crushed, and the projections 26 are less likely to bite into the skin of the wearer. This results in almost no longitudinal creases in the skin of the wearer. Therefore, at least one of the lateral flexural rigidity and the longitudinal flexural rigidity of the skin-side panel portion 221 needs to be 0.0096N · m 2 /m×10 -4 The following. Preferably, the transverse flexural rigidity which largely influences wrinkle formation is 0.0096N · m 2 /m×10 -4 The following. More preferably, the flexural rigidity in both directions is 0.0096N · m 2 /m×10 -4 The following.
However, when the flexural rigidity of the skin-side panel portion 221 is 0.0096N · m 2 /m×10 -4 In the following case, the cushioning property of the skin-side sheet 221 is weakened. Therefore, for example, when only the skin-side sheet portion 221 is disposed on the skin side of the elastic thread 23, the linear load of the elastic thread 23 is less likely to be absorbed and relaxed by the skin-side sheet portion 221. When the skin side panel portion 221 has high drapability, the waistline portion 20 comes into contact with the skin of the wearer in a state in which the skin side panel portion 221 is adhered to the periphery of the elastic thread 23, that is, in a state in which the contour of the elastic thread 23 is raised from the skin-side surface of the waistline portion 20. In this case, the linear load of the elastic threads 23 may be applied to the wearer's skin, so that the thread marks (the indentations of the elastic threads 23) are more likely to be generated on the wearer's skin.
In particular, with respect to the elastic threads 23a to 23e arranged on the waistline side with respect to the absorbent main body 10 (hereinafter, also referred to as "waistline-side elastic threads"), the absorbent main body 10 is not positioned on the skin side of these waistline-side elastic threads. Therefore, marks of the waistline-side elastic threads 23a to 23e may be generated on the skin of the wearer. The waistline of an infant as a target wearer of the diaper 1 according to the present embodiment is prominent in many cases. Therefore, the waistline-side elastic threads 23a to 23e may bite into the protruding waistline of the infant, and may generate a line mark on the waistline of the infant.
Thus, in the present embodiment, the inner layer panel portion 21 is disposed between the skin side panel portion 221 and the elastic thread 23 in the thickness direction of the waistline portion 20, and at least a part of the inner layer panel portion 21 is disposed on the waistline side with respect to the absorbent main body 10. The flexural rigidity of the inner sheet portion 21 by the KES method is set to a value higher (larger) than the flexural rigidity of the skin-side sheet portion 221.
Therefore, the inner sheet portion 21 having higher cushioning properties than the skin-side sheet portion 221 is disposed on the skin side with respect to the waistline-side elastic threads 23a to 23e, and the linear load of the waistline-side elastic threads 23a to 23e is absorbed and relaxed by the inner sheet portion 21. Since the inner layer sheet portion 21 is less likely to adhere to the waistline-side elastic strands 23a to 23e, the contours of the waistline-side elastic strands 23a to 23e are less likely to float out from the skin-side surface of the waistline portion 20. Therefore, the waistline-side elastic strands 23a to 23e are less likely to bite into the waistline of the wearer, and are less likely to cause line marks on the waistline of the wearer. Note that the flexural rigidity in at least one of the transverse direction and the longitudinal direction of the inner layer panel portion 21 may be higher than the flexural rigidity in at least one of the transverse direction and the longitudinal direction of the skin-side panel portion 221.
That is, in the case of the diaper 1 according to the present embodiment, crease lines and line lines of longitudinal gathers are less likely to be formed on the waistline of the wearer, and therefore, the sensitive skin of an infant can be prevented from being damaged. The inner layer sheet 21 is not positioned on the skin side, but the skin side sheet 221, which is more flexible than the inner layer sheet 21, is positioned on the skin side. A good tactile sensation on the wearer's skin can be maintained.
The flexural rigidity of the skin-side sheet portion 221 is more preferably 0.007N · m 2 /m×10 -4 The following. Therefore, it is less likely that crease lines of the wale are generated on the waistline of the wearer. The flexural rigidity of the inner layer sheet portion 21 is preferably 0.0096N · m 2 /m×10 -4 Above, or more preferably 0.015 N.m 2 /m×10 -4 The above. Alternatively, the flexural rigidity of the inner layer sheet portion 21 may be two times or more the flexural rigidity of the skin-side sheet portion 221, or the difference between the two flexural rigidities may be 0.005N · m 2 /m×10 -4 As described above. This makes it less likely to cause a line mark on the waistline of the wearer.
In the waistline portion 20 shown in fig. 5, the elastic thread 23 elongated in the transverse direction is sandwiched and fixed between a part of the first sheet 21 and the second sheet 22 (non-skin side sheet portion 222), and the part of the first sheet 21 serves as the inner sheet portion 21. Therefore, as in the waistline portion 20 of fig. 7 described later, the configuration can be simplified as compared with the case where the high-rigidity inner side panel portion 24 is provided in addition to the first panel 21 and the second panel 22 sandwiching the elastic thread 23 therebetween.
In addition, in the waistline portion 20 shown in fig. 5, a portion obtained by folding the longitudinal waistline-side end portion (of the non-skin-side-panel portion 222) of the second panel 22 toward the skin side is used as the skin-side-panel portion 221. Therefore, the flexural rigidity of the non-skin-side sheet 222 by the KES method like the skin-side sheet 221 is 0.0096N · m 2 /m×10 -4 Hereinafter, the sheet is flexible. This makes it possible to improve the feeling of the waist portion 20 on the non-skin side. In particular, in the case of the diaper 1 for infants, since the infant care giver or the like does not wear the diaper 1, the infant care giver or the like hardly feels a good feeling of the waist portion 20 on the skin side in practice. Improving the feeling of the waist portion 20 on the non-skin side can give an impression that the infant care apparatus or the like is a product having a good feeling of the diaper 1.
However, the present invention is not limited to the configuration of the waistline portion 20 shown in fig. 5. For example, the skin-side sheet portion 221 and the non-skin-side sheet portion 222 may be formed of separate sheets. The flexural rigidity of the non-skin-side sheet portion 222 is not limited to 0.0096N · m 2 /m×10 -4 The following.
Note that the flexural rigidity of the skin side sheet portion 221 and the flexural rigidity of the inner sheet portion 21 based on the KES method may be measured by using A measuring tester (A pure bending tester KES-FB2-AUTO-A manufactured by Kato Tech limited). Specifically, each of the skin-side sheet portion 221 and the inner-layer sheet portion 21 was cut into a 10cm × 10cm sheet serving as a sample. Then, each sample was fixed between chucks of a measuring tester so that flexural rigidity of the sample in the lateral direction could be measured. Each sample was bent to the front side to a maximum curvature of +2.5cm -1 Bending to the inner side to the maximum curvature of-2.5 cm -1 And then returns to the original position. According to the inclination when the bending moment relative to the curvature is approximately constant after the forward bending starts and the inclination relative to the curvature after the inward bending startsThe flexural rigidity value is calculated as the average value of the inclinations when the inclination of the ratio is substantially constant. The measurement was repeated five times for each sample, and the average value of the obtained values was used as the flexural rigidity. The flexural rigidity of the other sheet portions (described later) can also be measured similarly.
In this case, in the waistline portion 20, a portion located on the waistline side with respect to the absorbent main body 10 in the longitudinal direction is referred to as a waistline side portion 20A, and a portion overlapping with the absorbent main body 10 in the thickness direction is referred to as an absorbent main body side portion 20B. In the absorbent main body side portion 20B, a portion overlapping the absorbent core 11A in the thickness direction is referred to as a core side portion 20D, and a portion between the waistline side portion 20A and the core side portion 20D in the longitudinal direction is referred to as an intermediate portion 20C.
The value (F1/L1) obtained by dividing the magnitude of the force F1 for extending the waist side portion 20A in the transverse direction by the longitudinal length L1 of the waist side portion 20A is preferably smaller than the value (F2/L2) obtained by dividing the magnitude of the force F2 for extending the absorbent body side portion 20B in the transverse direction by the longitudinal length L2 of the absorbent body side portion 20B.
That is, the lateral contractive force per unit width in the longitudinal direction of the waistline side portion 20A is preferably smaller than the lateral contractive force per unit width in the longitudinal direction of the absorbent main body side portion 20B. This can reduce the pinching of the waistline of the wearer caused by the waistline-side elastic threads 23a to 23 e. Therefore, the line mark is less likely to be generated on the waistline of the wearer. On the other hand, increasing the stretchable force of the absorbent main body side portion 20B allows the absorbent main body 10 to come into close contact with the wearer. This makes it possible to hardly generate a gap between the absorbent main body 10 and the wearer, so that leakage of excrement can be suppressed. In addition, in the case where the absorbent main body 10 absorbs excrement and increases weight, sagging of the absorbent main body 10 can be suppressed, so that the fit of the absorbent main body 10 can be maintained.
For example, in the case where the lateral stretching force is reduced, at least one of the following adjustments may be made: reduction in fineness (reduction in diameter) of the elastic thread 23; reducing the elongation rate of the elastic strands 23; reducing the effective length of the elastic strands 23; the number of elastic strands 23 per unit width in the longitudinal direction is reduced. The elongation of the elastic thread 23 is the elongation when the natural length of the elastic thread 23 is defined as 1. The effective length of the elastic thread 23 is the length of the portion where the elastic thread 23 exhibits stretchability, and is the length of the portion where the elastic thread 23 in an extended state is fixed to the sheet. In case of an increase of the lateral stretching force, the adjustment can be made in the opposite way.
Specifically, the fineness of the waist side elastic threads 23a to 23e may be 200 to 1100dtex, or preferably 300 to 1000 dtex. If the fineness is less than 200dtex, there is a risk that the elastic threads 23a to 23e cannot exhibit the required stretchability. If the titer is greater than 1100dtex, there is a risk that the elastic threads 23 are more likely to be visually recognized from the outside of the diaper 1, giving the user the impression that the diaper 1 is waisted. Specifically, the pitch of the waist side elastic strands 23a to 23e (the distance between the centers of the elastic strands 23 adjacent to each other in the longitudinal direction) may be in the range of about 2.0mm to 12.0mm, or preferably in the range of about 4.0mm to 10.0 mm. Therefore, when the waist portion 20 is fitted on the wearer, a wrinkle mark or a line mark is less likely to be generated on the waist of the wearer.
Further, it is preferable that the value (F3/L3) obtained by dividing the magnitude of the force F3 per unit length of the intermediate portion 20C extending in the transverse direction by the longitudinal length L3 of the intermediate portion 20C is maximized, the value (F4/L4) obtained by dividing the magnitude of the force F4 per unit length of the core side portion 20D extending in the transverse direction by the longitudinal length L4 of the core side portion 20D is minimized, and the value (F1/L1) obtained by dividing the magnitude of the force F1 per unit length of the waist side portion 20A extending in the transverse direction by the longitudinal length L1 of the waist side portion 20A is minimized.
This can prevent contraction of the waistline side portions 20A and suppress excessive contraction of the core side portions 20D in the transverse direction while suppressing sagging of the absorbent main body 10 at the intermediate portion 20C. Therefore, the flatness of the absorbent core 11A can be maintained so that a gap is hardly generated between the absorbent main body 10 and the wearer. Therefore, leakage of excrement can be suppressed.
Note that the method of measuring the forces F1 to F4 that elongate the respective portions 20A to 20D of the waistline portion 20 by unit length in the lateral direction may be a known method. For example, a target portion is cut out from the diaper 1 as a sample. It is assumed that the sample includes effective length portions of all the elastic threads 23 included in the respective portions 20A to 20D. Both end portions of the sample corresponding to the transverse direction of the diaper 1 are held by chucks of a tensile tester such as an Autograph (AGS-G100N) manufactured by SHIMADZU corporation. Then, the load (N) obtained when the specimen is stretched by separating the chuck by a unit length can be used as the magnitude of the forces F1 to F4 that elongate the unit length in the transverse direction.
As shown in fig. 5, it is preferable that the waist side end 21a of the inner sheet portion 21 is located on the waist side in the longitudinal direction with respect to the elastic strands 23a arranged on the waist-most side among the plurality of elastic strands 23 included in the waist portion 20. Similarly, the crotch-side end 21b of the inner sheet 21 is preferably positioned on the crotch side in the longitudinal direction with respect to the waist-side end 10a of the absorbent main body 10.
Therefore, the inner sheet portion 21 can be disposed on the skin side with respect to the greater number of the waistline-side elastic threads 23a to 23 e. Therefore, it is less likely that line marks due to more elastic threads 23a to 23e are generated on the waistline of the wearer.
Although the inner sheet portion 21 is preferably provided on the skin side of all the waistline-side elastic threads 23a to 23e as in the present embodiment (fig. 5), the present invention is not limited thereto. The inner sheet portion 21 may be provided between at least one elastic thread 23 of the waistline-side elastic threads 23a to 23e and the skin-side sheet portion 221.
The waist portion 20 is modified by
Fig. 6 to 9 are sectional views of modified examples of the waistline unit 20.
The waistline portion 20 shown in fig. 6 has a configuration similar to that shown in fig. 5. Between the first sheet 21 and the second sheet 22 (non-skin-side sheet portion 222), the elastic thread 23 is sandwiched and fixed, and the first sheet 21 corresponds to the inner-layer sheet portion 21. The first sheet 21 has a flexural rigidity higher than that of the skin-side sheet portion 221. However, in fig. 6, the longitudinal waistline-side end portion 212 of the inner sheet portion 21 is folded toward the skin side together with the second sheet 22.
Therefore, the non-folded portion 211 and the folded portion 212 of the inner sheet portion 21 are disposed on the skin side of the waistline-side elastic threads 23a to 23 e. The linear load of the waistline-side elastic strands 23a to 23e is absorbed and relaxed by the two-ply inner- layer panel portions 211 and 212. Therefore, the waistline-side elastic threads 23a to 23e are less likely to bite into the waistline of the wearer and less likely to cause line marks on the waistline of the wearer.
In the waistline portion 20 shown in fig. 7, similarly to fig. 5, a part of the second sheet 22 serves as the non-skin side panel portion 222, and a part provided by folding the waistline-side end portion of the second sheet 22 serves as the skin side panel portion 221. However, in fig. 7, with respect to the first sheet 21 in which the elastic threads 23 are fixed by sandwiching the elastic threads 23 between the first sheet 21 and the second sheet 22 (non-skin side sheet portion 222), the flexural rigidity (at least one of the lateral flexural rigidity and the longitudinal flexural rigidity) based on the KES method is 0.0096N · m 2 /m×10 -4 The following. That is, the first sheet 21 is a sheet having the same flexibility as the skin-side sheet 221, and corresponds to the second inner-layer sheet.
Thus, in the waistline portion 20 shown in fig. 7, the inner layer panel portion 24 is disposed between the second inner layer panel portion 21 and the skin side panel portion 221. The inner sheet portion 24 is a separate sheet from the first sheet 21 and the second sheet 22. The flexural rigidity of the inner layer panel portion 24 is higher than the flexural rigidity of the skin side panel portion 221. Therefore, the inner sheet portion 24 is less likely to cause a line mark on the skin of the wearer.
In the case of the waistline portion 20 shown in fig. 7, the longitudinal length of the inner sheet portion 24 having high rigidity may be smaller than the longitudinal length of the first sheet 21. Specifically, it is preferable that the longitudinal length of the inner sheet portion 24 is a length that the inner sheet portion 24 can cover the waistline-side elastic threads 23a to 23e from the skin side. Therefore, in the waistline portion 20 shown in fig. 7, the range in which the inner layer panel portion 24 having higher rigidity is disposed can be narrower than that in the waistline portion 20 shown in fig. 5. The flexibility of the waist portion 20 can be increased.
In the waistline unit 20 shown in fig. 8, the first sheet 21 in which the elastic strands 23 are fixed by sandwiching the elastic strands 23 between the first sheet 21 and the second sheet 22 (non-skin side sheet portion 222) is provided with the inner sheet portion 25 on the skin side with respect to the first sheet 21. The inner sheet portion 25 is a separate sheet from the first sheet 21 and the second sheet 22. The flexural rigidity of the inner layer panel portion 25 is higher than the flexural rigidity of the skin side panel portion 221. The first sheet 21 corresponds to the third inner-layer sheet portion 21.
In fig. 8, the arrangement of the elastic threads 23 varies according to their longitudinal position. Specifically, the waistline-side elastic threads 23a to 23e are disposed between the inner layer sheet portion 25 and the third inner layer sheet portion 21 in the thickness direction. In contrast, the core-side elastic threads 23f disposed in the core-side portion 20D are disposed between the third inner-layer sheet portion 21 and the non-skin-side sheet portion 222 in the thickness direction. Likewise, the intermediate elastic thread 23g disposed in the intermediate portion 20C is preferably disposed between the third inner-layer sheet portion 21 and the non-skin-side sheet portion 222 in the thickness direction.
In this case, the waistline-side elastic threads 23a to 23e are further arranged on the skin side, making it difficult to visually recognize from the outside (non-skin side) of the diaper 1. Therefore, the impression that the waistline side portion 20A fits softly to the waistline of the wearer can be given to the user. In contrast, the core-side elastic threads 23f and the intermediate elastic threads 23g are further arranged on the non-skin side, so that they are easily visually recognized from the outside of the diaper 1. This makes it possible to give the user the impression that the absorbent core 11A and the absorbent main body 10 have high fit and little leakage due to the elastic threads 23.
Since the flexural rigidity of the inner layer panel portion 25 based on the KES method is higher than the flexural rigidity of the skin-side panel portion 221, a line mark is less likely to be generated on the waistline of the wearer. In particular, in this case, it is preferable that the stretchable force of the waistline side portion 20A (i.e., the value obtained by dividing the magnitude of the force for extending the waistline side portion 20A in the unit length in the lateral direction by the longitudinal length of the waistline side portion 20A) is smaller than the stretchable force of the other portions 20C and 20D. Therefore, although the waistline-side elastic threads 23a to 23e are further positioned on the skin side, thread marks are less likely to be generated on the waistline of the wearer.
The rigidity of the third inner layer panel portion 21 may be greater than the flexural rigidity of the skin-side panel portion 221, or may be equal to or less than the flexural rigidity of the skin-side panel portion 221. Although not shown, the following configuration may also be adopted: a portion formed by folding the waistline-side end portion of the first sheet 21 serves as an inner-layer sheet portion (25) and an unfolded portion serves as a third inner-layer sheet portion (21).
In the waistline portion 20 shown in fig. 9, the inner sheet portion 25 extends to the crotch side and the number of the intermediate elastic threads 23g positioned in the intermediate portion 20C is increased as compared with the waistline portion 20 shown in fig. 8. Specifically, some of the intermediate elastic threads 23g are arranged between the inner sheet portion 25 and the third inner sheet portion 21 in the thickness direction, and other intermediate elastic threads 23g are arranged between the third inner sheet portion 21 and the non-skin side sheet portion 222 in the thickness direction.
The intermediate portion 20C has the elastic threads 23g arranged in such a manner as to overlap each other in the thickness direction, so that the expansion and contraction force of the intermediate portion 20C (i.e., the value obtained by dividing the magnitude of the force by which the intermediate portion 20C is elongated in the lateral direction by the unit length of the intermediate portion 20C by the longitudinal length of the intermediate portion 20C) can be made larger than those of the other portions 20A, 20D. This can prevent contraction of the waistline side portions 20A and suppress excessive contraction of the core side portions 20D in the transverse direction while suppressing sagging of the absorbent main body 10 at the intermediate portion 20C. Therefore, the flatness of the absorbent core 11A can be maintained so that a gap is hardly generated between the absorbent main body 10 and the wearer. Therefore, leakage of excrement can be suppressed.
< second embodiment >
Disposable diaper 1 of the pants type
Fig. 10 is a perspective view of a pants-type disposable diaper 1 (hereinafter, referred to as "diaper") according to a second embodiment. Fig. 11 is a plan view of the diaper 1 in an unfolded and extended state. Fig. 12 is a sectional view taken along line I-I in fig. 11. Hereinafter, the configuration of the diaper 1 according to the second embodiment is explained mainly from the point different from the diaper 1 according to the first embodiment.
As shown in fig. 12, the diaper 1 of the second embodiment is configured such that the abdominal-side waistline portion 20 (back-side waistline portion 30) includes a first panel 21(31), a second panel 22(32), and a plurality of elastic threads 23(33) which are stretchable in the transverse direction. The plurality of elastic threads 23(33) are arranged side by side in the longitudinal direction between the first sheet 21(31) and the second sheet 22(32) and fixed in a state of being elongated in the transverse direction. Therefore, the abdominal-side waistline portion 20 and the back-side waistline portion 30 stretch in the lateral direction and fit to the waistline of the wearer. Suitable examples of the elastic threads 23 and 33 are styrene-based rubber, urethane-based rubber, ester-based rubber, and other known synthetic rubbers made of polyurethane or polyethylene, in addition to natural rubber in the form of threads.
In the back-side waistline portion 30, an elastic thread 33 is arranged in a region from the upper end portion to the lower end portion of the back-side waistline portion 30. In contrast, the elastic strands 23 are not arranged in the upper end portion of the abdominal-side waistline portion 20. In contrast, a stretchable sheet stretchable in the transverse direction is disposed in the upper end portion of the abdominal-side waistline portion 20. In the longitudinal direction, the stretchable sheet and the elastic threads 23 may be arranged in such a manner as to overlap each other or in such a manner as to be completely staggered from each other.
In the upper end portion of the abdominal-side waistline portion 20, since the stretchable sheet is arranged without the elastic thread 23, the upper end portion of the abdominal-side waistline portion 20 is in close contact with the wearer's ground. Therefore, local contraction is suppressed and a trace of the stretchable member is less likely to be left. In particular, since the abdomen of the infant protrudes, it is preferable to suppress the contraction of the abdomen-side waist portion 20.
The stretchability of the waistline opening BH is greatly affected by the stretching force of the upper end portions of the waistline portions 20 and 30 when the diaper 1 is worn by a wearer. The stretchable sheet has a property of being easily stretched from a natural state and hardly being contracted from the stretched state. Since the stretchable sheet is disposed at the upper end portion of the abdomen-side waist portion 20, the waist opening BH is easily expanded when the diaper 1 is worn by a wearer, and the diaper 1 can be prevented from being pulled against the abdomen portion after the waist portion 20 is fitted to the wearer.
Examples of the stretchable sheet include a nonwoven fabric subjected to an appropriate stretching treatment such as gear stretching or the like or a plastic film sheet having stretchability, which contains a polyurethane-based elastomer which is a thermoplastic elastomer fiber having elasticity and polypropylene (PP) which is a thermoplastic resin fiber having no elasticity and a polyolefin-based resin.
In the diaper 1 according to the present embodiment, only the abdomen-side waistline portion 20 includes the stretchable sheet, but is not limited thereto. Both the ventral-side waistline portion 20 and the dorsal-side waistline portion 30 can include a stretch panel. Alternatively, the abdominal-side waistline portion 20 may not include a stretch sheet, and only the back-side waistline portion 30 may include a stretch sheet.
The characteristic portion of the abdomen-side waist portion 20 is defined as follows
Fig. 13A is a schematic sectional view illustrating a contracted state of the skin-side sheet portion 400 according to the comparative example, and fig. 13B is a schematic sectional view illustrating a contracted state of the skin-side sheet portion 221 according to the present embodiment. Fig. 14 is an enlarged view of a sectional view of the abdominal-side waistline unit 20 shown in fig. 12.
At least one of the pair of waistline portions 20, 30 included in the diaper 1 according to the present embodiment has the following characteristic features. Hereinafter, the abdomen-side waist portion 20 will be described as an example; however, the back-side waistline portion 30 does not necessarily have the following characteristic portions. Alternatively, both the abdominal-side waistline portion 20 and the back-side waistline portion 30 may have the following characteristic portions; or the back waistline portion 30 alone may have the following characteristic portions, while the abdomen waistline portion 20 does not have the following characteristic portions.
The abdomen-side waist portion 20 (hereinafter, also simply referred to as "waist portion 20") includes the first sheet 21, the second sheet 22, the plurality of elastic threads 23, and the stretchable sheet as described above. A portion of the second sheet 22 serves as a non-skin side sheet portion 222, and the non-skin side sheet portion 222 is a portion disposed at a position closest to the non-skin side of the waistline portion 20. The longitudinal waistline-side end portion of the second sheet 22 is folded toward the skin side and is positioned on the skin side with respect to the absorbent main body 10. This folded portion serves as a skin-side panel portion 221 disposed at the most skin-side position of the waistline portion 20.
The first sheet 21 is disposed between the non-skin side sheet portion 222 and the absorbent main body 10 in the thickness direction. The plurality of elastic strands 23 are arranged between the non-skin side panel portion 222 and the first sheet 21 in the thickness direction. The stretchable sheet is disposed between the skin-side sheet portion 221 and the absorbent main body 10 in the thickness direction. Materials adjacent to each other in the thickness direction are bonded with an adhesive 50 shown in fig. 14.
Since the skin-side panel portion 221 is in direct contact with the skin of the wearer at the waistline portion 20, a flexible sheet having low flexural rigidity is used as the skin-side panel portion 221. This can improve the feel of the skin side panel portion 221 on the skin of the wearer.
Specifically, as a result of an experiment conducted by the inventorsIt was found that the flexural rigidity of the skin-side sheet portion 221 by the KES method is preferably 0.0096N · m 2 /m×10 -4 The following. Generally, the waist portion 20 of the diaper 1 is provided with an extensible member (an extensible sheet and elastic threads 23) which is extensible in the lateral direction so as to fit to the waist of the wearer. The waist portion 20 is contracted in the transverse direction by the stretchable member, and irregularities are formed in the thickness direction, and the irregularities are positioned side by side in the transverse direction in the waist portion 20. The irregularities are long in the longitudinal direction; in other words, the waistline portion 20 has a wale formed therein.
Therefore, the flexural rigidity of the skin-side sheet 400 is more than 0.0096N · m 2 /m×10 -4 In addition, when the skin-side sheet 400 has high flexural rigidity, large and uniform irregularities are formed in the skin-side sheet 400 due to contraction of the stretchable member, as in the comparative example shown in fig. 13A. Further, the shape retentivity (resiliency) of the protruding portion 410 protruding toward the skin side is improved. When the skin-side sheet portion 400 comes into contact with the wearer, the protruding portion 410 is hardly crushed, and the protruding portion 410 may deeply bite into the skin of the wearer. Thus, a longitudinal crease (an impression formed by the protrusion 410) may be generated on the skin of the wearer.
In contrast, according to the present embodiment, the flexural rigidity of the skin-side sheet portion 221 is set to 0.0096N · m 2 /m×10 -4 The following. The skin-side sheet 221 is a sheet having high drapability and hanging loosely. Therefore, as shown in fig. 13B, uneven unevenness having repeated fine undulations is formed in the skin-side sheet portion 221 due to contraction of the stretchable member. That is, the skin side panel portion 221 is smooth, and the contact area between the skin side panel portion 221 and the wearer's skin can be increased. Therefore, the contact pressure of the skin side sheet portion 221 due to the stretchable member can be dispersed, and thus the large tab 410 such as shown in fig. 13A according to the comparative example is suppressed from locally contacting the skin of the wearer. Further, the shape retentivity (resiliency) of the protruding portion 250 protruding toward the skin side is reduced. Therefore, when the skin side panel portions 221 come into contact with the wearer, the protrusions 250 may be crushed, and the protrusions 250 are less likely to bite into the skin of the wearer. This makes it hardly on the wearer's skinLongitudinal creases are generated. Therefore, at least one of the lateral flexural rigidity and the longitudinal flexural rigidity of the skin-side panel portion 221 needs to be 0.0096N · m 2 /m×10 -4 The following. Preferably, the transverse flexural rigidity which largely influences wrinkle formation is 0.0096N · m 2 /m×10 -4 The following. More preferably, the flexural rigidity in both directions is 0.0096N · m 2 /m×10 -4 The following.
In the longitudinal waistline-side end portion of the absorbent main body 10, a plurality of materials are laminated on each other and coated with an adhesive. The end may be relatively stiff. Therefore, the longitudinal waist-side end edge 10a of the absorbent main body 10 (i.e., the edge in the step between the portion having the absorbent main body 10 and the portion not having the absorbent main body 10) may bite into the skin of the wearer. The end edge 10a of the absorbent body 10 is also formed with irregularities due to contraction of the stretchable member. However, the protruding portion of the end edge 10a of the absorbent main body is hard and unlikely to be crushed, and therefore the protruding portion may locally bite into the skin of the wearer. The waistline of an infant as a subject to wear the diaper 1 according to the present embodiment is prominent in many cases. The end edge 10a of the absorbent main body 10 may bite into the waistline of an infant whose waistline is protruding.
In the waistline portion 20 shown in fig. 14, a skin-side sheet portion 221 is disposed across the end edge 10a of the absorbent main body 10 on the skin side of the absorbent main body 10. However, the flexural rigidity of the skin-side sheet portion 221 is as low as 0.0096N · m 2 /m×10 -4 The skin-side sheet 221 has low cushioning properties. Therefore, the hardness and the step of the end edge 10a of the absorbent main body 10 are less likely to be absorbed and relaxed by the skin-side sheet portion 221. Therefore, for example, when only the skin-side sheet portion 221 is disposed on the skin side with respect to the end edge 10a of the absorbent main body 10, the end edge 10a of the absorbent main body 10 bites into the skin of the wearer, marks or the like are generated on the skin, and the marks may damage the skin of the wearer.
Therefore, in the diaper 1 according to the present embodiment, the stretchable sheet as the inner sheet portion is disposed on the non-skin side with respect to the skin-side sheet portion 221, and the flexural rigidity of the stretchable sheet based on the KES method is made higher (larger) than that of the skin-side sheet portion 221. The stretchable sheet is provided on the skin side of the absorbent main body 10 so as to straddle the longitudinal waist-side end edge 10a of the absorbent main body 10. That is, the stretchable sheet covers the end edge 10a of the absorbent main body 10 from the skin side.
Therefore, the stretchable sheet having a higher cushioning property than that of the skin-side sheet portion 221 is disposed on the skin side with respect to the end edge 10a of the absorbent main body 10, and the absorption relaxes the hardness and the step of the end edge 10a of the absorbent main body 10. Therefore, the end edges 10a of the absorbent main body 10 are less likely to bite into the skin of the wearer, the skin of the wearer can be suppressed from being damaged by the end edges 10a of the absorbent main body 10, and the feeling on the skin of the skin-side surface of the waist portion 20 can be improved. Note that it is only necessary that at least one of the transverse flexural rigidity and the longitudinal flexural rigidity of the stretchable sheet (inner sheet portion) be higher than at least one of the transverse flexural rigidity and the longitudinal flexural rigidity of the skin-side sheet portion 221.
As described above, in the diaper 1 according to the present embodiment, crease marks of longitudinal gathers and marks of the end edges 10a of the absorbent main body 10 are less likely to occur at the waistline of the wearer. Therefore, sensitive skin damage of infants can be inhibited. The stretchable sheet having a high stiffness is not positioned on the skin side but the skin-side sheet portion 221, which is softer than the inner sheet portion 21, is positioned on the skin side. A good tactile sensation on the wearer's skin can be maintained.
The flexural rigidity of the skin-side sheet portion 221 is more preferably 0.007N · m 2 /m×10 -4 The following. Therefore, it is less likely that crease lines of the wale are generated on the waistline of the wearer. The flexural rigidity of the inner sheet portion (stretchable sheet in fig. 14) is preferably 0.0096N · m 2 /m×10 -4 Above, or more preferably 0.015 N.m 2 /m×10 -4 The above. Alternatively, the flexural rigidity of the inner layer sheet portion may be two or more times the flexural rigidity of the skin-side sheet portion 221, or the difference in flexural rigidity between the two sheet portions may be 0.005N · m 2 /m×10 -4 The above. This makes the end edges 10a of the absorbent main body 10 less likely to damage the wearer's skin.
In addition, in the waistline portion 20 shown in fig. 14A portion obtained by folding the longitudinal waistline-side end portion (of the non-skin-side sheet portion 222) of the second sheet 22 toward the skin side is used as the skin-side sheet portion 221. Therefore, the flexural rigidity of the non-skin-side sheet 222 by the KES method like the skin-side sheet 221 is 0.0096N · m 2 /m×10 -4 Hereinafter, the sheet is flexible. This makes it possible to improve the feeling of the waist portion 20 on the non-skin side. In particular, in the case of the diaper 1 for infants, since the infant care giver or the like does not wear the diaper 1, the infant care giver or the like hardly feels a good feeling of the waist portion 20 on the skin side in practice. Improving the feeling of the waist portion 20 on the non-skin side can give an impression that the infant care apparatus or the like is a product having a good feeling of the diaper 1.
However, the present invention is not limited to the configuration of the waistline portion 20 shown in fig. 14. For example, the skin-side sheet portion 221 and the non-skin-side sheet portion 222 may be formed of separate sheets. The flexural rigidity of the non-skin-side sheet portion 222 is not limited to 0.0096N · m 2 /m×10 -4 The following. The flexural rigidity of the first sheet 21 is not particularly limited, and may be 0.0096N · m 2 /m×10 -4 Below, or may be higher than 0.0096N · m 2 /m×10 -4 。
In the waistline unit 20 shown in fig. 14, the elastic thread 23 is arranged between the non-skin side panel portion 222 and the first panel 21. In contrast, an elastic sheet is disposed between the skin-side sheet portion 221 and the absorbent main body 10. Therefore, the use of the stretchable sheet to bring the waistline portion 20 into close contact with the wearer makes it possible to absorb and moderate the hardness and the step of the end edge 10a of the absorbent main body 10. Therefore, in the case of the waistline unit 20 shown in fig. 14, the structure can be simplified as compared with the case where a material for absorbing and relaxing the hardness and the step of the end edge 10a of the absorbent main body 10 is provided in addition to the stretchable sheet.
Note that the flexural rigidity of the skin-side sheet portion 221 by the KES method and the flexural rigidity of the inner sheet portion (stretchable sheet) by the KES method can be measured by using A measurement tester (pure bending tester KES-FB2-AUTO-A manufactured by Kato Tech co. Specifically, each of the skin-side sheet portion 221 and the inner sheet portion was cut into 10cm × 10cm pieces for use as samplesAnd (3) slicing. Then, each sample was fixed between chucks of a measuring tester so that flexural rigidity of the sample in the lateral direction could be measured. Each sample was bent to the front side to a maximum curvature of +2.5cm -1 Bending to the inner side to the maximum curvature of-2.5 cm -1 And then returns to the original position. The flexural rigidity value is calculated from an average value of an inclination at which the bending moment to the front side is substantially constant with respect to the inclination of the curvature and an inclination at which the bending moment to the back side is substantially constant with respect to the inclination of the curvature. The measurement was repeated five times for each sample, and the average value of the obtained values was used as the flexural rigidity. The flexural rigidity of the other sheet portions (described later) can also be measured similarly.
The crotch-side end edge 24a of the stretchable sheet is preferably positioned on the waist side in the longitudinal direction with respect to the waist-side end edge 11Aa of the absorbent core 11A. That is, the stretchable sheet preferably does not overlap with the absorbent core 11A in the thickness direction. Therefore, excessive contraction of the absorbent core 11A in the transverse direction due to the stretchable sheet can be suppressed. The flatness of the absorbent core 11A can be maintained. Therefore, a gap is less likely to be generated between the absorbent main body 10 and the wearer, and leakage of excrement can be suppressed. Also, deterioration in wearing comfort can be suppressed.
Although the flexural rigidity of the skin-side sheet portion 221 is low, it is also preferable to arrange the skin-side sheet portion 221 on the skin side of the absorbent main body 10 across the end edge 10a of the absorbent main body 10 like a stretchable sheet. Therefore, the hardness and the level difference of the end edge 10a of the absorbent main body 10 are absorbed and relaxed by the skin-side sheet 221 and the stretchable sheet. Therefore, as compared with the case where only the stretchable sheet is disposed on the skin side of the end edge 10a of the absorbent main body 10, the skin of the wearer can be further suppressed from being damaged by the end edge 10a of the absorbent main body 10.
In the longitudinal direction, the crotch-side end edge 221a of the skin-side sheet portion 221 extends further toward the crotch side than the crotch-side end edge 24a of the stretchable sheet, and therefore the stretchable sheet can be firmly fixed to the skin-side sheet portion 221. Therefore, the curl of the stretchable sheet is suppressed.
The waist portion 20 is modified by
Fig. 15 to 17 are sectional views of modified examples of the waistline unit 20.
In the waistline portion 20 shown in fig. 15, similarly to fig. 14, a part of the second sheet 22 serves as the non-skin side panel portion 222, and a part formed by folding the waistline-side end portion of the second sheet 22 serves as the skin side panel portion 221. In fig. 15, the first sheet 21 fixes the elastic thread 23 by sandwiching the elastic thread 23 between the first sheet 21 and the second sheet 22 (non-skin side sheet portion 222), and the first sheet 21 corresponds to the inner layer sheet portion. The first sheet 21 has a flexural rigidity higher than that of the skin-side sheet portion 221.
The inner sheet portion 21 (first sheet) includes a skin side 211 and a non-skin side 212; the skin side portion 211 is a portion formed by folding the longitudinal waistline-side end portion toward the skin side of the absorbent main body 10, and the non-skin side portion 212 is a portion disposed on the non-skin side with respect to the skin side portion 211. The skin side portion 211 of the inner sheet portion 21 is disposed on the skin side of the absorbent main body 10 across the longitudinal waist-side end edge 10a of the absorbent main body 10. Therefore, the hardness and the step of the end edge 10a of the absorbent main body 10 are absorbed and relaxed by the skin side portion 211 of the inner sheet portion 21, and the skin of the wearer can be prevented from being damaged by the end edge 10a of the absorbent main body 10.
When the elastic thread 23 (stretchable member) is disposed between the non-skin side portion 212 and the non-skin side portion 22 of the inner sheet portion 21 in the thickness direction, a stretchable sheet (stretchable sheet portion) is disposed between the skin side portion 211 and the non-skin side portion 212 of the inner sheet portion 21 in the thickness direction. In this case, the flexural rigidity of the stretchable sheet based on the KES method is preferably higher than the flexural rigidity of the skin-side sheet portion 221, and the stretchable sheet is preferably disposed on the skin side of the absorbent main body 10 so as to straddle the end edge 10a of the absorbent main body 10.
Therefore, the hardness and the step of the end edge 10a of the absorbent main body 10 are absorbed and relaxed by the two-layer sheet portion having high rigidity, that is, they are absorbed and relaxed by the skin side portion 211 of the inner layer sheet portion 21 and the stretchable sheet. Therefore, the skin of the wearer can be further inhibited from being damaged by the end edge 10a of the absorbent main body 10.
When a plurality of sheet portions other than the skin-side sheet portion 221 are arranged on the skin side of the end edge 10a of the absorbent main body 10 as shown in fig. 15, the flexural rigidity of at least one such sheet portion needs to be higher than the flexural rigidity of the skin-side sheet portion 221. In the waistline portion 20 of fig. 15, the flexural rigidity of the skin side portion 211 of the inner layer panel portion 21 may be equal to or less than the flexural rigidity of the skin side panel portion 221. In addition, the flexural rigidity of the stretchable sheet may be equal to or less than the flexural rigidity of the skin-side sheet portion 221. In this case, the stretchable sheet may be disposed between the non-skin side sheet portion 222 and the non-skin side portion 212 of the inner sheet portion 21.
The absorbent core 11A is a thick member, and the absorbent core 11A has high rigidity. Therefore, the longitudinal waist-side end edge 11Aa of the absorbent core 11A preferably does not reach the waist-side end edge 10a of the absorbent main body 10. When the absorbent core 11A is covered with the core wrap sheet 11B, the waist side end edge (not shown) of the core wrap sheet 11B preferably does not reach the end edge 10a of the absorbent main body 10. Therefore, the increase in the hardness and the step of the end edge 10a of the absorbent main body 10 by the absorbent core 11A and the core wrap sheet 11B can be suppressed. Therefore, the end edge 10a of the absorbent body 10 can be made as soft as possible, and the skin of the wearer can be prevented from being damaged by the end edge 10a of the absorbent body 10.
Preferably, the crotch-side end edge 211A of the skin-side portion 211 of the inner sheet portion 21 is located on the crotch side in the longitudinal direction with respect to the waist-side end edge 11Aa of the absorbent core 11A. Therefore, the hardness and the level difference of the end edge 11Aa of the absorbent core 11 are absorbed and relaxed by the skin side portion 211 of the inner layer sheet portion 21. Therefore, the skin of the wearer can be further suppressed from being damaged by the end edge 11Aa of the absorbent core 11A.
Also, similarly to the waistline portion 20 shown in fig. 14, it is preferable that the crotch side end edge 24a of the stretchable sheet is located on the waistline side in the longitudinal direction with respect to the waistline side end edge 11Aa of the absorbent core 11A. Therefore, excessive contraction of the absorbent core 11A in the lateral direction due to the stretchable sheet can be suppressed. The flatness of the absorbent core 11A can be maintained.
The waistline portion 20 shown in fig. 16 and 17 is different from the waistline portion 20 shown in fig. 15 in the length of the skin-side panel portion 221 in the longitudinal direction, and other configurations are the same as each other. Similar to the waistline portion 20 shown in fig. 17, the crotch-side end 221a of the skin-side panel portion 221 may be positioned on the waistline side with respect to the end edge 10a of the absorbent main body 10.
Similar to the waistline portion 20 shown in fig. 15 and fig. 16, the skin-side sheet portion 221 may be disposed on the skin side of the absorbent main body 10 across the end edge 10a of the absorbent main body 10. In this case, although the flexural rigidity of the skin-side sheet portion 221 is low, the hardness and the level difference of the end edge 10a of the absorbent main body 10 are absorbed and relaxed by the skin-side portion 211 of the inner layer sheet portion 21 and the skin-side sheet portion 221. Therefore, the skin of the wearer can be further inhibited from being damaged by the end edge 10a of the absorbent main body 10.
In the waistline portion 20 shown in fig. 15, the longitudinal length of the skin-side panel portion 221 is equal to the longitudinal length of the skin-side portion 211 of the inner-layer panel portion 21. In the case of the waistline portion 20 shown in fig. 16 and 17, the longitudinal length of the skin-side panel portion 221 is shorter than the longitudinal length of the skin-side portion 211 of the inner-layer panel portion 21. As described above, in the case where the crotch side end 221a of the skin side sheet portion 221 does not coincide with the crotch side end 211a of the skin side portion 211 of the inner sheet portion 21 in the longitudinal direction, the step at the crotch side end of each sheet portion can be reduced as compared with the case where the crotch side ends of the plurality of sheet portions are aligned with each other as shown in fig. 15. Therefore, the skin of the wearer can be prevented from being damaged by the crotch end of each sheet portion. Further, since the number of laminated layers of the sheet portions varies one by one in the longitudinal direction, a feeling of discomfort during use can be reduced.
Similarly, in the longitudinal direction, the crotch end 24a of the stretchable sheet preferably does not coincide with the crotch end 211a of the skin-side section 211 and the crotch end 221a of the skin-side sheet 221 of the inner sheet 21. Therefore, the skin of the wearer can be prevented from being damaged by the crotch end of each sheet portion, and discomfort during use can be reduced.
When the crotch-side end of each sheet is displaced, it is preferable that the crotch-side end edge 211a of the skin-side portion 211 of the inner-layer sheet 21 is located at the most crotch side in the longitudinal direction. Therefore, the skin-side sheet portion 221 and the stretchable sheet can be firmly fixed to the skin-side portion 211 of the inner sheet portion 21. This can suppress the following phenomenon: the skin-side sheet 221 having low stiffness is positioned on the most crotch side, and the crotch-side end of the skin-side sheet 221 is twisted; the stretchable sheet is positioned closest to the crotch side, and the crotch-side end of the stretchable sheet is curled.
Although not shown, the waistline-side end of the stretchable sheet may be folded together with the first sheet 21 and the second sheet 22 and positioned on the skin side and the non-skin side of the absorbent main body 10. In the case of the waistline portion 20 shown in fig. 15 to 17, elastic threads 23 may be disposed at the upper end portion of the waistline portion 20 instead of the stretchable sheet. The stretch panel may be disposed in a part or the whole of the waistline portion 20 without being limited to the upper end portion of the waistline portion 20.
The flexibility of the skin-side sheet portion 221 according to each of the first and second embodiments
As described above, in order to improve the feel of the waist portion 20 on the skin of the wearer and make crease marks of longitudinal folds less likely to occur on the skin of the wearer, the skin side panel portion 221 is a sheet having high flexibility (having high drapability). The structure of the skin-side sheet 221 will be described below. The non-skin side panel portions 222 preferably have the same flexibility.
For the skin-side sheet portion 221, a nonwoven fabric made of fibers containing a thermoplastic synthetic resin and being a spunbond nonwoven fabric is used. More preferably, a spunbond fiber nonwoven fabric or a spunbond-meltblown-spunbond (SMS) fiber nonwoven fabric is preferably used. As the continuous fibers constituting such a nonwoven fabric, polyolefin-based thermoplastic fibers containing polypropylene (PP) and Polyethylene (PE) as various types of known synthetic resins are preferably used. In the present embodiment, a spunbond nonwoven fabric mainly containing polyethylene fibers is used.
Since the skin-side sheet portion 221 is formed of a spunbond nonwoven fabric formed of continuous fibers, the free ends of the fibers do not come into direct contact with the skin of the wearer, unlike an air-laid nonwoven fabric including staple fibers, or the like. In particular, when the wearer touches with the fingertip, the continuous fiber, which moves relatively freely, comes into contact with the fingerprint of the finger, while the free end of the fiber does not come into contact with the fingerprint, thereby providing a soft and fine texture to the skin. Unlike the case of using composite fibers or the like, a step of fibrillating the fibers is not required. The number of manufacturing steps is small and manufacturing costs can be reduced.
Since the skin-side sheet 221 is formed of a spunbond nonwoven fabric or SMS nonwoven fabric formed of continuous fibers, no fuzz appears on the surface of the sheet, and the sheet can provide the wearer with a smooth, pliable, and soft feel as compared to other synthetic fibers formed of staple fibers. In addition, the fiber orientation of the spunbond nonwoven fabric is easier to control than other nonwoven fabrics. Therefore, the complex waist portion 20 having the desired sheet tensile strength and stretchability in a well-balanced manner can be obtained.
The skin-side sheet 221 is a fibrous nonwoven fabric mainly containing polyethylene fibers. The percentage content of the polyethylene fiber with respect to the entire sheet is 70 to 100 mass%. Since the polyethylene fiber is softer than other thermoplastic resin fibers such as polypropylene fiber and PET (polyethylene terephthalate) fiber, when the percentage content of the polyethylene fiber is at least 70 mass%, the fiber is softer than the prior art nonwoven fabric in which the percentage content of the polyethylene fiber is 70 mass% or less. In addition, the polyethylene fiber has a large fiber diameter, and thus the gap between the fibers is large and has high air permeability. Therefore, the retention of moisture in the waistline portion 20 can be reduced.
When the skin-side sheet portion 221 is formed of a spunbond nonwoven fabric using continuous polyethylene fibers, the continuous fibers have a plurality of fused portions formed by thermally fusing the continuous fibers to each other by a heat treatment of a calendar embossing method (calendar embossing method). In the fusion portion, the respective constituent fibers are thermally fused and do not maintain the fiber shape, and a part thereof is converted into a film. Therefore, the fused portion has higher rigidity than the non-fused portion constituting the fiber.
The total area ratio of the fused portion with respect to the area of the skin-side sheet portion 221 is related to the texture of the sheet and the strength of the sheet. In view of this, the total area ratio of the fused portions is preferably 5% or more and 25% or less. When the total area ratio is less than 5%, the strength of the sheet may be reduced, and a part of the waist portion 20 may be broken during use. In contrast, when the total area ratio is more than 25%, the entire sheet may be hardened and the texture may be deteriorated.
The flexibility (specifically, "smoothness" and "pliable and soft feeling") of the skin-side sheet portion 221 can be checked by using the surface property, bending property, fiber density, fiber diameter, specific volume, compression property, and the like of the skin-side sheet portion 221.
The basis weight (mass per unit area) of the skin-side sheet portion 221 was 10g/m 2 Above and 30g/m 2 Below, or more preferably 12g/m 2 Above and 25g/m 2 The following. The thickness under a light load (0.49hPa) is preferably 0.10mm or more and 0.60mm or less. When the basis weight of the skin-side sheet portion 221 is less than 10g/m 2 In the case of the polyester resin, flexibility is high, but it is difficult to obtain sufficient tensile strength. When the basis weight exceeds 30g/m 2 When the strength is high, it is difficult to obtain sufficient flexibility.
The skin side sheet part 221 is at 0.49hPa (. apprxeq.0.5 gf/cm) 2 ) Has an apparent density of 0.02g/cm under load 3 Above and 0.1g/cm 3 Below, or preferably 0.04g/cm 3 Above and 0.08g/cm 3 The following. The apparent density under a load of 49.03hPa was 0.1g/cm 3 Above and 0.2g/cm 3 Below, or preferably 0.12g/cm 3 Above and 0.18g/cm 3 The following. The specific volume of the skin-side sheet portion 221 under a load of 0.49hPa is 10cm 3 More than g and 50cm 3 A/g or less, or preferably 12.0cm 3 More than g and 18.0cm 3 The ratio of the carbon atoms to the carbon atoms is less than g. Specific volume under a load of 49.03hPa of 5.0cm 3 More than g and 10cm 3 Less than g, or preferably 4.0cm 3 More than g and 8.0cm 3 The ratio of the carbon atoms to the carbon atoms is below g.
When the apparent density of the skin-side sheet portion 221 under a load of 0.49hPa is less than 0.02g/cm 3 In this case, the fused portion of the skin-side sheet portion 221 is reduced, and fuzz may occur. In contrast, when the apparent density under a load of 0.49hPa exceeds 0.1g/cm 3 When this occurs, the stiffness of the skin-side sheet portion 221 is relatively increased.
When the skin side sheet part 221 is at 49.03hPa (. apprxeq.50 gf/cm) 2 ) Is within a predetermined range and the fiber is compressed by pressing with a fingertip, since the fiber is easily crushed and has a low rebound resilience, the density increases, the fingerThe contact area between the tip and the fiber is relatively increased, the fiber easily adheres to the fingertip, and therefore the fingertip is given a soft feeling, and crease is less likely to be generated on the fiber.
The basis weight of the skin-side sheet portion 221 is measured according to the JISL1096 method. The apparent density was obtained using an average value (N ═ 3) calculated from the basis weight and thickness obtained by measurement. The specific volume of the skin-side sheet 221 is calculated by dividing the basis weight of the nonwoven fabric by the thickness of the nonwoven fabric.
The average fiber diameter of the constituent fibers (mainly polyethylene fibers) of the skin-side sheet 221 is 14 μm or more and 22 μm or less. Since the fiber diameter is large, the total area ratio of the area of the fusion portion to the skin-side sheet portion 221 is relatively small. This can reduce the flexural rigidity of the skin-side sheet portion 221.
< bending characteristics >
As described above, the flexural rigidity of the skin-side sheet portion 221 by the KES method is 0.0096N · m 2 /m×10 -4 The following. This makes the fiber easy to bend, increases the contact distance between the fiber and the fingertip contacting the fiber, and increases the friction coefficient MIU. As described above, the flexural rigidity of the skin-side sheet portion 221 by the KES method is preferably 0.0035N · m 2 /m×10 -4 The above. Flexural rigidity of less than 0.0035 N.m 2 /m×10 -4 In the case of (2), there is a risk that the tensile strength of the skin-side sheet portion 221 is reduced and a part of the waist portion 20 is broken during use. As a result, the coefficient of variation MMD/MIU × 100 of the friction coefficient is 2% or more and 6% or less, and therefore the variation of the friction coefficient is reduced and the skin-side sheet portion 221 becomes smoother. That is, the amount of fibers attached to the fingerprint of the fingertip is increased, giving a smooth feeling.
< compression characteristics >
The compressive working load WC of the skin-side sheet portion 221 by the KES method is preferably 0.14N · m/m 2 Above and 0.2 N.m/m 2 Hereinafter, the compression recovery rate RC is preferably 15% or more and 50% or less. A compression working load WC of more than 0.2 N.m/m 2 When the waist portion 20 comes into contact with the wearer, the waist portion 20 contracts to form a protrusionThe exits 26, 250 are less likely to crush and are likely to bite into the wearer's skin. In the case where the compression recovery rate RC is more than 50%, when the waist portion 20 comes into contact with the wearer, the force of the crushed protrusions 26, 250 to be recovered to the original state is strong, and the local contact pressure of the protrusions 26, 250 on the skin of the wearer increases. In comparison, WC is less than 0.14 Nm/m 2 Or in the case where the compression recovery rate RC is less than 15%, the rigidity of the waistline portion 20 is excessively low, and a part of the waistline portion 20 may break during use. By setting the compression working load WC and the compression recovery rate RC of the skin side panel portion 221 in the above-described ranges, it is less likely to cause creases in the waistline of the wearer while appropriately obtaining the tensile strength of the waistline portion 20.
< surface Property >
The skin-side sheet portion 221 is a fiber web formed by thermally fusing continuous fibers mainly composed of polyethylene fibers to each other. Since the free ends of the fibers are not present on the surface, the amount of fuzz is small, and the sheet surface has good smoothness. Furthermore, polyethylene fibers are soft compared to polypropylene fibers. Polyethylene fibers have a soft surface, deform under slight loads, and follow and conform to the movements of the wearer's body as it moves.
The skin-side sheet portion 221 has a friction coefficient MIU of 0.15 or more and 0.40 or less, more preferably 0.25 or more and 0.35 or less, on the surface thereof, and an average deviation MMD of the friction coefficient of 0.008 or more and 0.01 or less. Since the friction coefficient MIU exceeds 0.15, the frictional resistance is high. When the wearer touches the sheet surface, the wearer can feel a smooth feeling such as adhesion of the fibers to the wearer's skin. The coefficient of variation MMD/MIU 100 of the coefficient of friction is 2.0% or more and 6.0% or less. As described above, when the compression recovery rate RC is less than 50%, the fibers are crushed and the fiber density is increased even under a slight load applied when the fingertips of the wearer are in contact with the fibers. The amount of fiber in contact with the fingertips increases and the friction coefficient MIU increases. Therefore, the coefficient of variation MMD/MIU 100% of the friction coefficient falls within a range of a small predetermined value. The variation in the coefficient of friction is reduced, provides suitable smoothness as a whole, has a larger amount of fibers that are in contact with the user's fingertips in a manner of adhering to fingerprints, and can impart a smooth, pliable and soft feel to the wearer.
The ranges of the predetermined values of the bending property and the surface property of the skin-side sheet portion 221 may be satisfied in at least one of the lateral direction and the longitudinal direction of the waistline portion 20, or more preferably in both directions. The measurement of each mechanics based on the KES method in this specification is described in detail in "standardization and analysis of style evaluation" 2 nd edition (japanese textile machinery society style evaluation and standardization committee published on 7/10 1980).
Referring to table 1, various nonwoven fabrics were produced under various conditions, and their characteristics and properties were evaluated. The nonwoven fabrics of examples 1 to 5 were formed of spunbond nonwoven fabrics containing 100 mass% of polyethylene fibers as continuous fibers. The nonwoven fabric of comparative example 1 was formed of a spunbond nonwoven fabric containing 100 mass% of polypropylene fibers as continuous fibers. Further, in the manufacturing step, the nonwoven fabrics of examples 1 to 5 and comparative examples 1 and 2 were subjected to heat treatment by a calendering method using a heat-embossing roll.
The test subjects put the diaper 1 having the skin side panel portions 221 using the nonwoven fabrics of examples 1 to 5 and comparative examples 1 to 3, respectively, on infants and young children and evaluated the possibility of occurrence of crease marks and the tensile strength in two steps. According to the skin of the infant after wearing the diaper, ". smallcircle" is selected as the diaper for the test subject to feel "less likely to form wrinkles", and "x" is selected as the diaper 1 for the test subject to feel "likely to generate wrinkles". Regarding the tensile strength, ". smallcircle" is selected for the diaper 1 in which the waist portion 20 is broken in use, and "x" is selected for the diaper 1 in which the waist portion 20 is not broken.
TABLE 1
Figure GDA0003482892800000351
< example 1>
For the nonwoven fabric of example 1, a nonwoven fabric having a basis weight of 2 was used0.40g/m 2 A spunbonded nonwoven fabric comprising polyethylene fibers having an average fiber diameter of 14.83. mu.m.
< example 2>
For the nonwoven fabric of example 2, a nonwoven fabric having a basis weight of 18.98g/m was used 2 A spunbonded nonwoven fabric comprising polyethylene fibers having an average fiber diameter of 16.89 μm.
< example 3>
For the nonwoven fabric of example 3, a nonwoven fabric having a basis weight of 20.84g/m was used 2 A spunbonded nonwoven fabric comprising polyethylene fibers having an average fiber diameter of 20.28. mu.m.
< example 4>
For the nonwoven fabric of example 4, a nonwoven fabric having a basis weight of 25.12g/m was used 2 A spunbonded nonwoven fabric comprising polyethylene fibers having an average fiber diameter of 16.77 μm.
< example 5>
For the nonwoven fabric of example 5, a nonwoven fabric having a basis weight of 15.14g/m was used 2 A spunbonded nonwoven fabric comprising polyethylene fibers having an average fiber diameter of 16.77 μm.
< comparative example 1>
The nonwoven fabric of comparative example 1 was used in a mass basis of 20.37g/m 2 A spunbonded nonwoven fabric comprising polypropylene fibers having an average fiber diameter of 12.19. mu.m.
< comparative example 2>
For the nonwoven fabric of comparative example 2, a nonwoven fabric having a basis weight of 15.08g/m was used 2 And a composite fiber having an average fiber diameter of 17.35 μm. For the composite fiber, a continuous fiber and a core-sheath type composite fiber including a core portion made of polypropylene and a sheath portion made of polyethylene are used.
< comparative example 3>
As the nonwoven fabric of comparative example 3, a breathable nonwoven fabric composed of conjugate fibers having a basis weight of 23.52g/m was used 2 And the average fiber diameter was 16.64. mu.m. For the composite fiber, a core-sheath type composite fiber is used, which is a short fiber having a fiber length of 51mm and comprises polyethylene terephthalateA core made of alcohol ester (PET) and a sheath made of polyethylene.
The basis weight, fiber diameter, surface characteristics (MIU, MMD/MIU), bending characteristics (B) and compression characteristics (T0, Tm, WC, RC) of each nonwoven fabric were measured by the following methods.
< method of measuring basis weight >
A sample of 100mm × 200mm (N ═ 10) was obtained from each nonwoven fabric, the basis weight of the sample was obtained, and the average of the obtained basis weights was used as the basis weight of each nonwoven fabric.
< method for measuring average fiber diameter >
Samples of 10mm × 10mm were prepared by cutting out samples from each nonwoven fabric and placing them on preforms, respectively. An appropriate amount of glycerol was dropped onto each sample to soak the entire sample in glycerol and a cover slip was placed on the sample. Then, the chip surface of each sample was observed at a magnification of 1000 times using a known optical Microscope (for example, VHC-100 Digital Microscope Lens VH-Z450 manufactured by KEYENCE, Inc.). The fiber diameter of the fiber (N50) exposed from the sheet surface was measured, and the average value thereof was used as the average fiber diameter.
< method for measuring surface Property >
The surface characteristics were measured by taking each nonwoven fabric ranging 100mm × 100mm as a sample using KES-FB4-a-AUTO (automated surface tester) manufactured by Kato Tech co. In the production of each nonwoven fabric, each sample was horizontally moved 0 to 2cm in the machine direction (direction in which the fibers were oriented) at a constant speed of 0.1 cm/sec using a rubbing head (gauge head) having an outer dimension of 5mm × 5mm, and under the condition that the initial load was 50gf, each numerical value in the case where MIU is the average friction coefficient in the moving section and MMD is the standard deviation of the friction coefficient was calculated. Five identical measurements were performed for each sample, and the average of the measurement results was used as the value of MIU and the value of MMD for each sample.
< methods for measuring thickness T0, Tm, and compression Property >
For measuring the thickness of the individual nonwovens, the method known from Kato Tech was usedCompression tester KES-FB3-AUTO-A manufactured by Limited corporation. First, a piece having a size of 100mm × 100mm was cut out from each nonwoven fabric to be used as a sample, the center of the sample was gently sandwiched between disks arranged above and below, and a measurement was made when the compressed area (area of the disk) was 2.0cm 2 And a thickness T0 for each sample at a load of 0.49 hPa. Then, the measurement sample was compressed at a load of 49.03hPa at a loading rate of 0.02 mm/sec, and the thickness Tm was measured at a load of 49.03 hPa. Further, WC represents the operating load (N · m/m) required to compress from thickness T0 to thickness Tm 2 ) And WC2 represents a work load required to return from the thickness Tm to the thickness T0, the compression recovery rate RC (%) is obtained according to the following calculation formula.
RC(％)＝WC2/WC×100
< measurement results >
Referring to the results in table 1, it is clear that, as in comparative examples 1 to 3, when the flexural rigidity of the nonwoven fabric was more than 0.0096N · m 2 /m×10 -4 When the nonwoven fabric had a flexural rigidity of 0.0096N · m as in examples 1 to 5, crease marks were easily generated on the skin of the wearer 2 /m×10 -4 When the above is described below, wrinkle marks are less likely to be generated on the skin of the wearer. Further, it is clear that, as in example 5, when the flexural rigidity is 0.0035N · m 2 /m×10 -4 In the above, the waistline portion 20 is not broken in use, and the nonwoven fabric of example 5 can be used as the skin-side sheet portion 221 without any problem.
In addition, the nonwoven fabric according to any one of examples 1 to 5 had a compression recovery rate RC of 50% or less, which was lower than that of the nonwoven fabric according to any one of comparative examples 1 to 3. In view of this, it is also clear that the flexible nonwoven fabric of low flexural rigidity has a protrusion portion in the wrinkle which is easily crushed, and wrinkle marks are less likely to be generated.
Further, the basis weight of the nonwoven fabric according to any one of embodiments 1 to 5 is 10g/m 2 Above and 30g/m 2 In the following range, the apparent density under a load of 49.03hPa falls within 0.12g/cm 3 Above and 0.2g/cm 3 Within the following ranges. Thus, it is possible to provideAs long as the basis weight and the apparent density of the nonwoven fabric are within the above ranges, flexibility can be obtained while obtaining appropriate tensile strength.
Comparing example 1 (nonwoven fabric composed of polyethylene fibers having a fiber diameter of 14.83 μm) with comparative example 1 (nonwoven fabric composed of polypropylene fibers having a fiber diameter of 12.19 μm), the MIU of example 1 was 0.335, whereas the MIU of comparative example 1 was 0.238, the coefficient of variation MMD/MIU × 100 of example 1 was 2.57%, whereas the coefficient of variation MMD/MIU × 100 of the coefficient of friction of comparative example 1 was 3.28%. Therefore, since the nonwoven fabric is composed of relatively soft polyethylene fibers, the friction coefficient MIU is relatively high. As a result, the coefficient of variation MMD/MIU X100 of the friction coefficient is low, the variation of the friction coefficient is reduced, and the sheet surface is smooth. Therefore, when the user moves the fingertip in the planar direction with respect to the surface of the nonwoven fabric, the amount of fibers that come into contact with the fingerprint so as to adhere to the fingerprint is large, and a smooth feeling can be imparted.
With respect to the nonwoven fabric of any one of comparative examples 2 and 3 composed of composite fibers, the coefficient of variation MMD/MIU × 100 of the friction coefficient exceeded 6%. Therefore, the smoothness of the sheet surface was deteriorated as compared with the nonwoven fabric of any one of examples 1 to 5 composed of single fibers of polyethylene fibers. In other words, in the case where the nonwoven fabric according to any one of embodiments 1 to 5 is composed of polyethylene fibers having a fiber diameter of 14 μm or more and 22 μm or less, it is easy to obtain a soft nonwoven fabric having a smooth sheet surface with a coefficient of variation MMD/MIU × 100 of friction coefficient of 2% or more and 6% or less based on the KES method. The measurement results of the friction coefficient MIU according to examples 1, 2, 4 and 5 were 0.268 to 0.335, and thus the friction coefficient MIU was preferably at least 0.25 (above).
The embodiments of the present invention have been described above, however, the above embodiments are for easier understanding of the present invention, and are not intended to explain the present invention in a limiting manner. In addition, the present invention may be modified or improved without departing from the idea thereof, and includes equivalents of modified or improved configurations.
Description of the reference numerals
Pants-type disposable diaper (absorbent article)
10 absorbent body
11 absorbent body, 11A absorbent core, 11B core wrap sheet
12 top sheet, 13 back sheet, 14 outer sheet
15 leg elastic member
20 flank side waist body part (waist body part)
20A waist side portion, 20B absorbent body side portion
20C center section, 20D core side section
21 first sheet (inner sheet, second inner sheet, third inner sheet)
22 second sheet, 221 skin side sheet part, 222 non-skin side sheet part
23 elastic threads (stretchable members), 23a to 23e waistline-side elastic threads
23f core side elastic threads, 23g center elastic threads
24 inner sheet portion, 25 inner sheet portion, 26 projecting portion
30 back waist part (waist part), 31 first sheet
32 second sheet, 33 elastic thread
40 waistline part of comparative example
50 adhesive
24 stretchable sheet (stretchable sheet portion, inner sheet portion), 250 projecting portion
Skin side sheet of 400 comparative example

Claims (23)

1. An absorbent article having a longitudinal direction and a transverse direction,
the absorbent article includes:
an absorbent body comprising an absorbent core; and
a pair of waistline portions, each waistline portion including a skin side panel portion and a plurality of elastic strands,
the skin-side sheet portion is disposed at a position closest to the skin side,
the plurality of elastic threads are stretchable in the transverse direction,
in at least one of the pair of waistline portions,
the flexural rigidity of the skin side sheet portion by the KES method is 0.0096N · m 2 /m×10 -4 In the following, the following description is given,
the waist body part is provided with an inner layer sheet part,
the inner sheet portion is located on a waist side in the longitudinal direction with respect to the absorbent main body,
the inner sheet portion is located between the skin-side sheet portion and the elastic thread in the thickness direction of the waist portion,
the flexural rigidity of the inner layer sheet portion based on the KES method is higher than the flexural rigidity of the skin side sheet portion,
the waistline portion has a waistline side portion and an absorbent main body side portion,
the waist side portion is a portion located on the waist side in the longitudinal direction with respect to the absorbent main body,
the absorbent main body side portion is a portion overlapping with the absorbent main body in the thickness direction, and
a value obtained by dividing the magnitude of a force for elongating the waist side portion by a unit length in the transverse direction by the length of the waist side portion in the longitudinal direction
Is less than
A value obtained by dividing the magnitude of a force for elongating the absorbent body side portion by a unit length in the transverse direction by the length of the absorbent body side portion in the longitudinal direction,
the flexural rigidity of the skin side panel part by the KES method is 0.0035 N.m 2 /m×10 -4 In the above-mentioned manner,
the skin side sheet has a compression recovery rate RC of 15% or more and 50% or less by the KES method,
the basis weight of the skin side sheet part was 10g/m 2 Above and 30g/m 2 Are as follows, and
the skin side sheet portion had a load of 49.03hPa of 0.12g/cm 3 Above and 0.2g/cm 3 The following apparent density.
2. The absorbent article according to claim 1,
the waist portion includes a non-skin-side sheet portion disposed at a position closest to the non-skin side,
the elastic thread is arranged between the inner sheet portion and the non-skin side sheet portion in the thickness direction, and
the skin-side sheet portion is a portion obtained by folding a waist-side end portion of the non-skin-side sheet portion in the longitudinal direction toward a skin side.
3. The absorbent article according to claim 2,
the waist-side end portion in the longitudinal direction of the inner layer panel portion is folded toward the skin side.
4. The absorbent article according to claim 1,
the waist body part comprises a second inner layer sheet part and a non-skin side sheet part,
the second inner sheet portion is disposed on a non-skin side with respect to the inner sheet portion,
the non-skin side sheet portion is disposed at a position closest to the non-skin side,
the second inner sheet portion has a flexural rigidity of 0.0096N · m according to the KES method 2 /m×10 -4 In the following, the following description is given,
the elastic thread is arranged between the second inner-layer sheet portion and the non-skin-side sheet portion in the thickness direction, and
the skin-side sheet portion is a portion formed by folding a waistline-side end portion of the non-skin-side sheet portion in the longitudinal direction toward a skin side.
5. The absorbent article according to claim 1,
the waistline part comprises a third inner layer sheet part and a non-skin side sheet part,
the third inner sheet portion is disposed on a non-skin side with respect to the inner sheet portion,
the non-skin side sheet portion is disposed at a position closest to the non-skin side,
the waistline part is provided with a waistline side part and a core side part,
the waist side portion is a portion located on the waist side in the longitudinal direction with respect to the absorbent main body,
the core side portion is a portion overlapping with the absorbent core in the thickness direction,
the plurality of elastic strands includes a waist-side elastic strand disposed at the waist side portion and a core-side elastic strand disposed at the core side portion,
the waistline-side elastic thread is disposed between the inner sheet portion and the third inner sheet portion in the thickness direction, and
the core-side elastic thread is disposed between the third inner-layer sheet portion and the non-skin-side sheet portion in the thickness direction.
6. The absorbent article according to claim 5,
the waistline portion has an intermediate portion between the waistline side portion and the core side portion in the longitudinal direction,
the plurality of elastic strands includes a middle elastic strand disposed at the middle portion, and
some of the intermediate elastic threads are arranged at a position between the inner-layer sheet portion and the third inner-layer sheet portion in the thickness direction, and
some of the intermediate elastic threads are arranged at a position between the third inner-layer sheet portion and the non-skin-side sheet portion in the thickness direction.
7. The absorbent article according to claim 1,
the waist-side end of the inner layer panel portion is located on the waist side in the longitudinal direction with respect to the elastic thread arranged at a position most toward the waist side among the plurality of elastic threads.
8. The absorbent article according to claim 1,
the crotch side end of the inner sheet is located on the crotch side in the longitudinal direction with respect to the waist side end of the absorbent main body.
9. The absorbent article according to claim 1,
the skin side sheet part contains fibers having a fiber diameter of 14 to 22 [ mu ] m, and
the coefficient of variation MMD/MIU 100 of the coefficient of friction of the skin side sheet portion by the KES method is 2% or more and 6% or less.
10. The absorbent article according to claim 1,
the skin side sheet portion has a friction coefficient MIU of at least 0.25.
11. The absorbent article according to claim 1,
the skin side panel portion comprises polyethylene fibers.
12. An absorbent article having a longitudinal direction and a transverse direction,
the absorbent article includes:
an absorbent body comprising an absorbent core; and
a pair of waist portions each including a skin-side sheet portion disposed at a position closest to the skin side,
in at least one of the pair of waistline portions,
the flexural rigidity of the skin side sheet portion by the KES method is 0.0096N · m 2 /m×10 -4 In the following, the following description is given,
an inner sheet portion is arranged on the non-skin side with respect to the skin-side sheet portion,
the flexural rigidity of the inner sheet portion based on the KES method is higher than that of the skin-side sheet portion,
the inner sheet portion is disposed on the skin side of the absorbent main body and spans a waist-side end edge of the absorbent main body in the longitudinal direction,
the flexural rigidity of the skin side panel part by the KES method is 0.0035 N.m 2 /m×10 -4 In the above-mentioned manner,
the skin side sheet has a compression recovery rate RC of 15% or more and 50% or less by the KES method,
the basis weight of the skin side panel part is 10g/m 2 Above and 30g/m 2 Are as follows, and
the skin side sheet portion had a load of 49.03hPa of 0.12g/cm 3 Above and 0.2g/cm 3 The following apparent density.
13. The absorbent article of claim 12,
the waistline portion includes a non-skin side sheet portion disposed at a position closest to the non-skin side,
the skin-side sheet portion is a portion formed by folding a waistline-side end portion of the non-skin-side sheet portion in the longitudinal direction toward a skin side,
the inner sheet portion has a skin-side portion and a non-skin side portion,
the skin side portion is a portion formed by folding the waistline-side end portion in the longitudinal direction toward the skin side,
the non-skin side portion is a portion arranged on the non-skin side with respect to the skin side portion,
a stretchable sheet portion is disposed between the non-skin-side portion of the inner sheet portion and the non-skin-side sheet portion in the thickness direction of the waist portion,
the stretchable sheet portion is stretchable in the transverse direction and
the skin-side portion of the inner sheet portion is disposed on the skin-side of the absorbent main body, spanning the waist-side end edge of the absorbent main body in the longitudinal direction.
14. The absorbent article according to claim 12 or 13,
a crotch-side end edge of the skin-side portion of the inner sheet portion is located on the crotch side in the longitudinal direction with respect to a waist-side end edge of the absorbent core.
15. The absorbent article of claim 13,
the elastic sheet portion has a flexural rigidity according to the KES method higher than that of the skin-side sheet portion, and
the stretchable sheet portion is disposed on the skin side of the absorbent main body, spanning a waist-side end edge of the absorbent main body in the longitudinal direction.
16. The absorbent article of claim 15,
the crotch-side end edge of the skin-side portion of the inner sheet, the crotch-side end edge of the skin-side sheet, and the crotch-side end edge of the stretchable sheet are offset from each other in the longitudinal direction.
17. The absorbent article of claim 16,
the crotch-side end edge of the skin-side portion of the inner sheet portion is located on the crotch-side most in the longitudinal direction.
18. The absorbent article of claim 12,
the inner sheet portion is a stretchable sheet portion stretchable in the transverse direction.
19. The absorbent article of claim 15,
the crotch-side end edge of the stretchable sheet portion is positioned on the waist side in the longitudinal direction with respect to the waist-side end edge of the absorbent core.
20. The absorbent article of claim 12,
the skin-side sheet portion is disposed on the skin side of the absorbent main body and spans a waist-side end edge of the absorbent main body in the longitudinal direction.
21. The absorbent article of claim 12,
the skin side sheet part contains fibers having a fiber diameter of 14 to 22 [ mu ] m, and
the coefficient of variation MMD/MIU 100 of the coefficient of friction of the skin side sheet portion by the KES method is 2% or more and 6% or less.
22. The absorbent article of claim 12,
the skin side sheet portion has a friction coefficient MIU of at least 0.25.
23. The absorbent article of claim 12,
the skin side panel portion comprises polyethylene fibers.
CN201980027659.7A 2018-04-24 2019-04-05 Absorbent article Active CN112004507B (en)

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KR101415547B1 (en) * 2006-11-27 2014-07-08 가오 가부시키가이샤 Absorbent article
JP5884489B2 (en) * 2012-01-05 2016-03-15 王子ホールディングス株式会社 Disposable diaper, its manufacturing method, and its manufacturing apparatus
JP2014176527A (en) * 2013-03-15 2014-09-25 Hakujuji Co Ltd Disposable absorbent article

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CN101541284A (en) * 2006-11-27 2009-09-23 花王株式会社 Absorbent article
JP2008142316A (en) * 2006-12-11 2008-06-26 Kao Corp Underwear type disposable diaper
CN102665631A (en) * 2009-12-22 2012-09-12 尤妮佳股份有限公司 Disposable wearing article
CN103717188A (en) * 2011-08-09 2014-04-09 花王株式会社 Underpants type absorbent article
CN106659613A (en) * 2014-08-27 2017-05-10 宝洁公司 Wearable article having elastic belt
TW201705926A (en) * 2015-06-30 2017-02-16 Unicharm Corp Absorbent article having slits inclined toward one direction of waist elastic

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