CN111971010B

CN111971010B - Underpants-type wearing article

Info

Publication number: CN111971010B
Application number: CN201980025513.9A
Authority: CN
Inventors: 光野聪; 池内谦仁; 栗田范朋
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2018-06-29
Filing date: 2019-06-11
Publication date: 2023-02-03
Anticipated expiration: 2039-06-11
Also published as: BR112020026047A2; CN111971010A; JP7207690B2; JP2020000718A; WO2020004008A1

Abstract

The present invention provides a pants-type wearing article, in which the arrangement of the seal portions constituting the side seal regions is the same, and in which, when the side seal regions are peeled, no lateral tearing occurs in the vicinity of the boundary where the number of stacked sheets changes. The sealing parts (51) are arranged in the same manner, and at least one side edge part (28) of the 1 st waist region (11) in the 1 st and 2 nd waist regions (11, 12) has a 1 st region (28A) positioned on the waist opening (26) side and a 2 nd region (28B) positioned on the leg opening (27) side. In the 1 st region (28A) and the 2 nd region (28B), the area of the side seal region (50) is within a predetermined range, and the number of stacked sheets forming the 1 st region (28A) is larger than the number of stacked sheets forming the 2 nd region (28B). The 1 st region (28A) includes a 1 st nonwoven fabric (71) mainly composed of 1 st fibers on the outer surface side and a 2 nd nonwoven fabric (72) mainly composed of 2 nd fibers on the inner surface side, the 1 st nonwoven fabric (71) has a tensile strength in the transverse direction (X) lower than that of the 2 nd nonwoven fabric (72), and the 1 st fibers have a melting point lower than that of the 2 nd fibers.

Description

Underpants-type wearing article

Technical Field

The present invention relates to a disposable diaper and a pants-type wearing article including a diaper pad.

Background

Conventionally, there has been known a disposable wearing article formed in a pants-type shape by side seams joining both side edge portions of front and rear waist regions to each other. For example, patent document 1 discloses a pants-type wearing article in which both side edge portions of front and rear waist regions are joined to each other via side seal regions having a plurality of seal portions intermittently arranged in a longitudinal direction. The side seal regions are divided into an upper region located on the waist opening side, a lower region located on the leg opening side, and an intermediate region located between the upper and lower regions.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-477

Disclosure of Invention

Problems to be solved by the invention

In the pants-type clothing article of the invention disclosed in patent document 1, the arrangement of the seal portions in the side seal regions is appropriately adjusted so that the seal strength in the intermediate region is lower than the seal strength in the upper and lower regions, and therefore, the separation of the upper and lower regions during wearing can be suppressed, and the separation of the intermediate region during disposal of the diaper can be easily performed.

However, since the number of stacked constituent sheets in the upper region is large, the quality is high, and the sealing strength is high, the rigidity is poor between the upper region and the intermediate region. As a result, when the peeling operation is performed, there is a possibility that lateral tearing may occur in the vicinity of the boundary between the upper region and the intermediate region where the arrangement of the seal portion is changed. Similarly, since the lower region has a higher number of stacked sheets, higher quality, and higher sealing strength than the intermediate region, a difference in rigidity occurs between the intermediate region and the lower region, and there is a possibility that a lateral tear may occur in the vicinity of a boundary between the intermediate region and the lower region where the arrangement of the sealing portion changes when the peeling operation is performed.

In order to suppress the lateral tearing, it is also conceivable to design and change the arrangement of the sealing portions in further detail in accordance with the number of stacked sheets, etc., but in this case, the structure of the manufacturing apparatus and the pressure-heating conditions have to be changed in the seal forming step at the time of product-by-product manufacturing, which is not preferable from the viewpoint of manufacturing cost.

The invention provides an underpants type wearing article, which does not generate transverse tearing in the vicinity of the boundary where the number of laminated sheets changes when a side sealing area is peeled.

Means for solving the problems

In order to solve the above-described problems, the present invention according to claim 1 and claim 2 relates to a pants-type worn article having a longitudinal direction and a transverse direction, and including a 1 st waist region, a 2 nd waist region, a waist opening defined by overlapping both side edge portions of the 1 st waist region and the 2 nd waist region with each other and joining the side edge portions via a side seal region having a plurality of seal portions discontinuously extending in the longitudinal direction, and a pair of leg openings.

In the pants-type worn article of the present invention, at least one side edge portion of the 1 st waist region out of the 1 st waist region and the 2 nd waist region has a 1 st region positioned on the waist opening side and a 2 nd region positioned on the leg opening side, and in the 1 st region and the 2 nd region, the side seal region has an area within a predetermined range, the number of stacked sheets forming the 1 st region is larger than the number of stacked sheets forming the 2 nd region, the 1 st region includes a 1 st nonwoven fabric mainly composed of 1 st fibers positioned on the outer surface side and a 2 nd nonwoven fabric mainly composed of 2 nd fibers positioned on the inner surface side, the tensile strength of the 1 st nonwoven fabric in the transverse direction is lower than the tensile strength of the 2 nd nonwoven fabric in the transverse direction, and the melting point of the 1 st fibers is lower than the melting point of the 2 nd fibers.

The underpants type wearing article of the present invention includes the following preferable embodiments.

(1) The 2 nd region includes the 1 st nonwoven fabric and the 2 nd nonwoven fabric.

(2) The 1 st fiber is a continuous fiber of a thermoplastic resin extending in the transverse direction, and the 1 st nonwoven fabric is a spunmelt nonwoven fabric.

(3) At least a part of the 1 st fibers is cut in the vicinity of the outer periphery of the seal portion.

(4) The 1 st fibers are predominantly polyethylene fibers and the 2 nd fibers are predominantly polyolefin fibers.

(5) The tensile strength in the transverse direction of the 1 st nonwoven fabric is less than the tensile strength in the longitudinal direction of the 2 nd nonwoven fabric.

Effects of the invention

In the pants-type wearing article of the present invention, when the side edge portions of the front and rear waist regions are separated from each other at the time of disposal, the side seal regions can be smoothly torn and peeled without causing a lateral tear in the vicinity of the boundary where the number of stacked sheets changes.

Drawings

Fig. 1 is a perspective view of a pants-type disposable diaper according to an embodiment of the pants-type wearing article of the present invention.

Fig. 2 is a partially cut-away developed plan view of the disposable diaper seen from the inner surface side, when each elastic body is stretched in the longitudinal and transverse directions to the maximum extension (the degree to which the gathers due to the contraction action of the elastic material are lost).

Fig. 3 is an exploded perspective view of the disposable diaper.

Fig. 4 is a sectional view taken along line IV-IV of fig. 1.

Fig. 5 (a) is an enlarged plan view of the side seal region. (b) Is a cross-sectional view taken along the line V (b) -V (b) in FIG. 5 (a).

Fig. 6 (a) is an enlarged view of the region surrounded by the one-dot chain line VI (a) of fig. 5 (b). (b) Is an enlarged view of the region surrounded by the one-dot chain line VI (b) of fig. 5 (b).

Fig. 7 (a) is a view showing a state where both side edge portions of the front and rear waist regions are separated by the 1 st separation mode. (b) The figure shows the case where both side edge portions of the front and rear waist regions are separated by the 2 nd separation method. (c) The figure shows the case where both side edge portions of the front and rear waist regions are separated by the 3 rd separation mode.

Fig. 8 (a) is a cross-sectional view of a side edge portion of the front waist region in the 1 st modification. Fig. 2 (b) is the same as fig. 8 (a). Fig. 3 (c) is a view similar to fig. 8 (a).

Fig. 9 (a) is the same as fig. 5 (a) in the 4 th modification. Fig. 5 (a) shows a modified example of fig. 5.

Detailed Description

The following embodiments relate to a disposable pants-type diaper (hereinafter, simply referred to as a diaper) 10 as an example of an embodiment for an absorbent article of the present invention, and include not only indispensable structures of the present invention but also optional and preferable structures. In fig. 2 and 3, each elastic body described later is stretched against the contraction force thereof to such an extent that the gathers produced in the member to which each elastic body is attached appear substantially to disappear by natural vision due to the contraction force in the lateral direction X and the longitudinal direction Y.

Referring to fig. 1 to 9, a diaper 10 has a longitudinal direction Y and a transverse direction X intersecting the longitudinal direction Y, a skin-non-facing surface on the opposite side of the skin-facing surface, a longitudinal centerline P bisecting the length dimension of the transverse direction X, and a transverse centerline Q bisecting the length dimension of the longitudinal direction Y, and is substantially symmetrical with respect to the longitudinal centerline, and includes a front waist region (1 st waist region or 2 nd waist region) 11, a rear waist region (2 nd waist region or 1 st waist region) 12, and a crotch region 13 located between the front waist region 11 and the rear waist region 12. The pants-type absorbent article according to the embodiment of the present invention includes, for example, disposable pants-type diapers and pants-type diaper pads for newborns, infants and adults.

The diaper (10) has: a front waist panel 14 forming the front waist region 11; a rear waist panel 15 forming a rear waist region 12; and an absorbent sheet 16 extending in the longitudinal direction Y between the front and

rear waist sheets

14, 15 to form the crotch region 13. The front waist panel 14 and the back waist panel 15 are formed in the same shape and the same size, for example.

The absorbent sheet 16 has: a front end portion 19A located on the skin-facing surface side of the front waist region 11; a rear end portion 19B located on the skin-facing surface side of the rear waist region 12; and an intermediate portion 19C located between the front and

rear end portions

19A, 19B. In the present embodiment, the front and

rear end portions

19A, 19B of the absorbent sheet 16 are positioned and fixed on the skin-facing surfaces of the front and

rear waist regions

11, 12, respectively, but the absorbent sheet 16 may be fixed to the outer surfaces of the front and

rear waist panels

14, 15 such that the front and

rear end portions

19A, 19B are positioned on the skin-non-facing surfaces of the front and

rear waist regions

11, 12.

Both side edge portions 28 of the front waist region 11 and both side edge portions 29 of the rear waist region 12 are joined to each other via side seal regions 50 intermittently extending in the longitudinal direction Y. The side seal region 50 has a plurality of seal portions 51 arranged apart in the longitudinal direction Y. By joining the

side edge portions

28, 29 of the front and

rear waist regions

11, 12 to each other via the side seal regions 50, the

side edge portions

7, 8 of the diaper 10 are formed, and the waist opening 26 and the pair of leg openings 27 are defined. The seal portion 51 can be formed by various known joining means based on a welding means such as heat sealing or ultrasonic wave, or a combination thereof.

The front waist panel 14 has a horizontally long rectangular shape defined by an inner end edge (inner end edge of front waist region) 14a forming a part of the front leg opening, an outer end edge (outer end edge of front waist region) 14b forming the front waist opening, and both

side edges

14c, 14d (both side edges of front waist region) extending in the longitudinal direction Y between the inner and

outer end edges

14a, 14 b.

Referring to fig. 2 and 3, the front waist sheet 14 includes a liquid-impermeable inner sheet 17 positioned on the skin-facing surface (inner surface) side and a liquid-impermeable outer sheet 18 positioned on the skin-non-facing surface (outer surface) side. The outer sheet 18 has a main portion 18A joined to the inner sheet 17 and a bent portion 18B extending outward in the longitudinal direction Y from the outer edge of the inner sheet 17. The folded portion 18B is folded inward in the longitudinal direction along a folding line 24A extending in the transverse direction X and fixed to the skin-facing surface side of the inner sheet 17 and the front end portion 19A so as to cover the front end portion 19A of the absorbent sheet 16 in a state where the front end portion 19A of the absorbent sheet 16 is disposed on the skin-facing surface side of the front waist sheet 14. Between the inner sheet 17 and the main body portion 18A of the outer sheet 18, a plurality of twisted or string-shaped front waist elastic bodies 20 are fixed so as to be contractible in the lateral direction X.

The rear waist panel 15 has: an inner end edge (inner end edge of rear waist region) 15a forming a part of the rear leg opening; an outer end edge (outer end edge of rear waist region) 15b forming the rear waist opening; and both side edges (both side edges of the rear waist region) 15c, 15d extending in the longitudinal direction Y between the inner and

outer end edges

15a, 15 b.

The back waist panel 15 has a liquid-impermeable inner sheet 21 positioned on the skin-facing surface side and a liquid-impermeable outer sheet 22 positioned on the skin-non-facing surface side. The outer sheet 22 has a main portion 22A joined to the inner sheet 21 and a bent portion 22B extending outward in the longitudinal direction Y from the outer edge of the inner sheet 21. The folded portion 22B is folded inward in the longitudinal direction along a folding line 24B extending in the transverse direction X and fixed to the skin-facing surface side of the inner sheet 21 and the rear end portion 19B so as to cover the rear end portion 19B of the absorbent sheet 16 in a state where the rear end portion 19B of the absorbent sheet 16 is disposed on the skin-facing surface side of the rear waist panel 15. Between the inner sheet 21 and the main body portion 22A of the outer sheet 22, a plurality of strand-like or string-like rear waist elastic bodies 23 are fixed so as to be contractible in the transverse direction X.

The outer sheet 18 of the front waist panel 14 and the outer sheet 22 of the back waist panel 15 are formed of the 1 st nonwoven fabric 71. The 1 st nonwoven fabric 71 is a fibrous nonwoven fabric containing a thermoplastic synthetic resin, and preferably a spunmelt fibrous nonwoven fabric, particularly a spunbond fibrous nonwoven fabric, SMS (spunbond-meltblown-spunbond) fibrous nonwoven fabric, is used. As the continuous fibers (1 st fibers) constituting these nonwoven fabrics, polyolefin thermoplastic fibers including polypropylene (PP) and Polyethylene (PE) are preferably used as various known synthetic fibers. In the present embodiment, as the 1 st nonwoven fabric 71, a spunbond nonwoven fabric mainly composed of polyethylene fibers is used.

The 1 st nonwoven fabric 71 is formed of a spun-bond nonwoven fabric made of continuous fibers, and unlike a hot-air nonwoven fabric or the like containing short fibers, the free ends of the fibers do not come into direct contact with the skin of the wearer. In particular, when the fingertip of the wearer touches the finger, the free ends of the fibers do not contact the fingerprint, and since the fibers are continuous fibers and have a high degree of freedom, the fibers can be twisted together and touch the fingerprint of the finger, and a soft and good skin feel can be provided. In addition, unlike the case of using short fibers or the like, since a fiber-opening step is not required, the number of production steps is small, and the production cost can be reduced.

The 1 st nonwoven fabric 71 is a spunbond nonwoven fabric or SMS nonwoven fabric made of continuous fibers, and is capable of giving a smooth and soft touch without fluffing the sheet surface as compared with other synthetic fibers made of short fibers. Further, since the spunbonded fiber nonwoven fabric tends to have higher nonwoven fabric strength than other fiber nonwoven fabrics, sheet breakage is less likely to occur when the diaper 10 is pulled up or worn.

Here, the "smooth, soft and soft touch" of the 1 st nonwoven fabric 71 includes, in addition to the touch of the wearer wearing the diaper 10, the touch of an assistor such as a mother wearing the diaper when the wearer is an infant or the like. In particular, when the wearing assistant assists wearing, the softness and the good skin feel of the diaper 10 are determined based on the feel when a part of the inner and outer surfaces of the diaper 10 is in contact with the fingertips. Specifically, when the first nonwoven fabric 71 forming the inner and outer surfaces of the diaper 10 is brought into contact with the wearer, the fibers give a feeling of entanglement of the finger fingerprints, thereby allowing the wearer to recognize that the diaper 10 is excellent in softness and texture.

The 1 st nonwoven fabric 71 is a fibrous nonwoven fabric mainly comprising 1 st fibers made of polyethylene fibers, and the content of the polyethylene fibers in the entire sheet is 70 to 100% by mass. Since polyethylene fibers are more flexible than other thermoplastic resin fibers such as polypropylene fibers and PET (polyethylene terephthalate) fibers, the polyethylene fibers have a content of at least 70 mass% and are more flexible than conventional nonwoven fabrics having a content of polyethylene fibers of 70 mass% or less. Further, since the polyethylene fiber has a relatively large fiber diameter, the fiber gap is relatively large, and the air permeability is excellent. Therefore, by using the 1 st nonwoven fabric 71 as the

outer sheets

18 and 22 of the diaper 10, the skin of the wearer can be well adhered, and the stuffiness inside the diaper 10 can be suppressed.

When the 1 st nonwoven fabric 71 is formed of a spunbond nonwoven fabric using continuous polyethylene fibers, the first nonwoven fabric has a plurality of fused portions formed by thermally fusing continuous fibers to each other by heat treatment by a calender embossing method. In the welded portion, the respective constituent fibers are thermally welded without maintaining the fiber shape, and a part of the fibers is formed into a film, and the rigidity is higher than that of the non-welded portion of the respective constituent fibers.

The total area ratio of the welded portions to the area of the 1 st nonwoven fabric 71 is related to the hand and tensile strength of the 1 st nonwoven fabric 71, but from this viewpoint, the total area ratio of the welded portions is preferably 5 to 25%. When the total area ratio is 5% or less, the tensile strength is lowered, and there is a possibility that a part of the absorbent article is damaged when worn, whereas when the total area ratio is 25% or more, the whole of the 1 st nonwoven fabric 71 becomes hard, and there is a possibility that the hand is impaired.

The mass of the 1 st nonwoven fabric 71 is, for example, 10 to 30g/m ² Preferably 12 to 25g/m ² The thickness dimension under a micro load (0.49 hPa) is 0.10-0.60 mm. The mass of the No. 1 nonwoven fabric 71 is less than 10g/m ² In the case of (2), although flexibility is excellent, it is difficult to obtain sufficient tensile strength. The mass of the No. 1 nonwoven fabric 71 exceeds 30g/m ² In the case of (2), a relatively high tensile strength can be obtained, but sufficient flexibility cannot be obtained, and the air permeability may be reduced.

0.49hPa (. Apprxeq.0.5 gf/cm) of No. 1 nonwoven fabric 71 ² ) The apparent density under load is 0.02-0.1 g/cm ³ Preferably 0.04 to 0.08g/cm ³ And an apparent density under a load of 49.03hPa of 0.1 to 0.2g/cm ³ Preferably 0.12 to 0.18g/cm ³ . The 1 st nonwoven fabric 71 has a specific volume under a load of 0.49hPa of 10 to 50cm ³ A/g, preferably 12.0 to 18.0cm ³ The specific volume of the specific surface area per gram under 49.03hPa load is 5.0-10 cm ³ A/g, preferably 4.0 to 8.0cm ³ /g。

The average fiber diameter of the constituent fibers (mainly polyethylene fibers) of the 1 st nonwoven fabric 71 is 14 to 22 μm. Since the fiber diameter of the 1 st nonwoven fabric 71 is relatively large, the number of fibers per unit area is relatively small, and the fiber density is suppressed low to form a large number of fiber gaps, so that it can be said that the nonwoven fabric has good air permeability.

The inner sheet 17 of the front waist panel 14 and the inner sheet 21 of the rear waist panel 15 are formed of a 2 nd nonwoven fabric 72 different from the 1 st nonwoven fabric 71. The 2 nd nonwoven fabric 72 is a fibrous nonwoven fabric containing a thermoplastic synthetic resin, and preferably a spunmelt fibrous nonwoven fabric, particularly a spunbond fibrous nonwoven fabric, SMS (spunbond-meltblown-spunbond) fibrous nonwoven fabric is used. As the 2 nd fiber constituting these nonwoven fabrics, a polyolefin-based thermoplastic fiber including polypropylene (PP) and Polyethylene (PE) which are various known synthetic fibers, a single fiber formed by using a component such as polyethylene terephthalate (PET) and nylon alone, a composite fiber formed by a plurality of these components, and the like can be used.

The composite fiber is preferably a composite fiber containing at least 2 or more components having mutually different melting points, and examples thereof include a sheath-core fiber, a side-by-side fiber, an island-in-sea fiber, a flat, Y-shaped, and C-shaped profiled fiber. In particular, from the viewpoint of industrial inexpensiveness, it is preferable to use a core-sheath fiber having a lower melting point of the component of the sheath portion than that of the component of the core portion, particularly a core-sheath fiber such as PET/PE or PP/PE (core/sheath portion).

The mass of the 2 nd nonwoven fabric 72 is, for example, 10 to 30g/m ² Preferably 12 to 25g/m ² The thickness dimension under a micro load (0.49 hPa) is 0.1-0.6 mm. Further, 0.49hPa (. Apprxeq.0.5 gf/cm) of the 2 nd nonwoven fabric 72 ² ) The apparent density under load is 0.02-0.1 g/cm ³ Preferably 0.04 to 0.08g/cm ³ The apparent density under 49.03hPa load is 0.1-0.2 g/cm ³ Preferably 0.12 to 0.18g/cm ³ 。

In the present embodiment, a spun-bonded nonwoven fabric mainly containing polyolefin fibers as the 2 nd fibers is used as the 2 nd nonwoven fabric 72. The 1 st nonwoven fabric 71 has a lower tensile strength at least in the transverse direction X (machine direction MD during nonwoven fabric production) than the 2 nd nonwoven fabric 72, and the melting point of the 1 st fiber mainly constituting the 1 st nonwoven fabric 71 is lower than the melting point of the 2 nd fiber mainly constituting the 2 nd nonwoven fabric 72.

< method for measuring melting Point >

The "melting point" of the 1 st fiber and the 2 nd fiber made of the thermoplastic resin fiber means the peak top temperature of an endothermic peak at the time of transition from a solid state to a liquid state when measured at a temperature rise rate of 10 ℃/minute in a differential scanning calorimeter. As the differential scanning calorimeter, for example, a DSC-60 type DSC measuring apparatus manufactured by Shimadzu corporation (Ltd.) can be used.

The mass of the 1 st and 2

nd nonwoven fabrics

71, 72 was measured by the JISL1096 method. The apparent density was determined from the average value (N = 3) calculated from the mass and thickness dimensions obtained by these measurements. The specific volume of the 1 st nonwoven fabric 71 and the 2 nd nonwoven fabric 72 was calculated by dividing the mass of the nonwoven fabric by the thickness thereof.

The front waist elastic body 20 has: a plurality of upper front waist elastic bodies 20A extending in the transverse direction X along the outer end edges 14 b; and a front lower waist elastic body 20B located between the front upper waist elastic body 20A and the inner end edge 14 a. The rear waist elastic body 23 has: a plurality of upper-rear waist elastic bodies 23A extending in the transverse direction X along the outer end edges 15b; and a rear lower waist elastic body 23B located between the rear upper waist elastic body 23A and the inner end edge 15 a.

The front lower waist elastic member 20B is disposed so as to overlap with both side portions of the front end portion 19A of the absorbent sheet 16 in a plan view of the diaper 10, and the rear lower waist elastic member 23B is disposed so as to overlap with both side portions of the rear end portion 19B of the absorbent sheet 16 in a plan view of the diaper 10. The front and rear lower waist

elastic members

20B, 23B are cut and removed at the center portions of the front and

rear end portions

19A, 19B of the absorbent sheet 16, respectively, without being elasticized, and define

inelastic regions

45, 46 at the center portions, where the contraction force of the front and rear lower waist

elastic members

20B, 23B does not act.

Of the front and rear waist elastic members 20, 23, the front and rear upper and lower waist

elastic members

20A, 20B, 23A, 23B are a plurality of string-like, or strand-like elastic members extending in the transverse direction X at intervals in the longitudinal direction Y. The plurality of

elastic bodies

20A, 20B, 23A, 23B are attached between the inner and

outer layer sheets

17, 18, 21, 22 in a state of, for example, an elongation of 1.5 to 3.0 times, preferably 2.2 to 2.7 times. The elongation ratio is 1.0 times, and means the degree of elongation when the length (natural length) of each elastic body in a non-stretched state is 1, and for example, an elongation ratio of 1.5 times means an increase in elongation of 0.5 times from the length of each elastic body in a non-stretched state.

As the elastic material, various known synthetic rubbers such as styrene rubber, urethane rubber, ester rubber, polyurethane, and polyethylene can be used without limitation, in addition to natural rubber. The fineness of each elastomer is not particularly limited, but is 200 to 1100dtex, preferably 300 to 1000dtex. When the fineness is less than 200dtex, the desired stretchability may not be exhibited in a state where the shape and size of the gathers are controlled by the pitch between the elastic members 20 and 23. When the fineness of each elastic body exceeds 1100dtex, each elastic body is easily seen through from the outside via the

outer sheets

18 and 22 positioned on the skin non-facing surface side of the diaper 10, and therefore, the elastic body is easily recognized as a diaper rather than underwear in appearance, and the aesthetic quality is impaired.

In the present embodiment, the inner and

outer sheets

17, 18, 21, and 22 are bonded to each other via an adhesive agent that is continuously or partially applied to the entire circumference of each elastic body interposed therebetween. Therefore, the pitch between the elastic bodies can also be said to be the separation dimension (pitch) of the joining line joining the inner and

outer sheets

17, 18, 21, 22 to each other. The stretchable sheet composed of the inner and

outer sheets

17, 18, 21, 22 and the front and rear waist elastic members 20, 23 is relatively flexible by fixing the inner and

outer sheets

17, 18, 21, 22 to each other only with the adhesive applied to the entire peripheries of the elastic members 20, 23 and by forming any one of the inner and

outer sheets

17, 18, 21, 22 with the first nonwoven fabric 71 described later.

Although not shown, a sheet having elastic stretchability may be disposed on the waist opening 26 side of the front and

rear waist panels

14 and 15 in addition to the front and rear upper waist

elastic members

20A and 23A or instead of the front and rear upper waist

elastic members

20A and 23A. In such a case, the adhesive sheet adheres more favorably to the skin of the wearer than in the case of having a linear elastic material.

The absorbent sheet 16 has a rectangular shape defined by front and rear end edges 16a, 16B and

side edges

16c, 16d, and the front and

rear end portions

19A, 19B are joined to each other via front and rear joining regions (not shown) formed by applying a hot-melt adhesive to skin-facing surfaces of the front and

rear waist sheets

14, 15. The hot-melt adhesive in the front and rear joining regions may be applied in various known forms such as an omega form, a spiral form, and a wave form, in addition to a plurality of lines extending in the longitudinal direction Y.

Referring to fig. 2 and 3, the absorbent sheet 16 includes a hydrophilic/liquid-permeable inner sheet (body-side liner) 31 positioned on the skin-facing surface side, an absorbent body 33, a hydrophobic cover sheet 40 positioned on the skin-non-facing surface side of the absorbent body 33, and a leakage preventing film 34 formed of a liquid-impermeable plastic film positioned between the absorbent body 33 and the cover sheet 40 and having a size covering at least the bottom surface of the absorbent body 33. The absorbent member 33 has a liquid-absorbent core 35 and a core-covering sheet 36 covering the entire liquid-absorbent core 35.

The liquid-absorbent core 35 has a semi-rigid sheet shape formed into a desired shape, and has front and rear end edges extending in the transverse direction X and both side edges extending convexly and curvedly toward the longitudinal center line P (inward in the transverse direction X) between the front and rear end edges. In addition, the liquid-absorbent core 35 is formed of a mixture of fluff wood pulp and superabsorbent polymer particles (SAP).

The cover sheet 40 has: a main body 41 on which the leakage preventing film 34 is disposed; and side portions 42 located on the outer side in the transverse direction X than

fold lines

25A, 25B extending in the longitudinal direction Y along both side edges of the leakage preventing film 34. The side portions 42 are folded along the

folding lines

25A and 25B toward the longitudinal center line P and overlap the body portion 41. A plurality of string-like or strand-like leg elastic members 38 extending in the longitudinal direction Y are attached between the side portions 42 and the leakage preventing film 34 so as to be contractible in an extended state. For the leg elastic body 38, for example, an elastic material having a fineness of 470 to 740dtex, and being stretched and fixed from a contracted or relaxed state by 1.7 to 2.3 times can be used. Leg elastic regions 39 on which leg elastic members 38 are arranged are formed at leg opening edges of the diaper 10, and the leg opening edges are brought into contact with the thighs of the wearer by contraction of the leg elastic regions 39, thereby effectively suppressing side leakage of excrement.

Referring to fig. 4, both side edge portions 28 of the front waist region 11 have an upper region 28A located on the waist opening 26 side, a lower region 28B located on the leg openings 27 side, and an intermediate region 28C located between the upper region 28A and the lower region 28B. Both side edge portions 29 of the rear waist region 12 have an upper region 29A located on the waist opening side, a lower region 29B located on the leg opening side, and an intermediate region 29C located between the upper region 29A and the lower region 29B.

The upper region 28A of both side edges of the front waist region 11 has a 3-layer structure of the main body portion 18A of the outer sheet 18, the inner sheet 17, and the folded portion 18B of the outer sheet 18, and the lower region 28B and the middle region 28C have a 2-layer structure of the outer sheet 18 and the inner sheet 17. The upper region 29A of the rear waist region 12 has a 3-layer structure of the main body portion 22A of the outer sheet 22, the inner sheet 21, and the folded portion 22B of the outer sheet 22, and the lower region 29B and the intermediate region 29C have a 2-layer structure of the outer sheet 22 and the inner sheet 21.

Referring to fig. 5 (a) and (b), for convenience of explanation, both

side edge portions

7 and 8 of the diaper 10 are divided into an upper region 61 positioned on the waist opening side, a lower region 62 positioned on the leg opening side, and an intermediate region 63 positioned between the upper region 61 and the lower region 62. The

side edge portions

7, 8 of the diaper 10 are formed by joining the

side edge portions

28, 29 of the front and

rear waist regions

11, 12 to each other via side seal regions 50, the upper region 61 is formed by the

upper regions

28A, 29A of the front and

rear waist regions

11, 12, the intermediate region 63 is formed by the

intermediate regions

28C, 29C of the front and

rear waist regions

11, 12, and the lower region 62 is formed by the

lower regions

28B, 29B of the front and

rear waist regions

11, 12. In the drawings and the following paragraphs, only the side edge portion 7 (one side edge portion) of the diaper 10 and the

side edge portions

28 and 29 of the front and

rear waist regions

11 and 12 forming the side edge portion are described as the subject, but the side edge portion 8 (the other side edge portion) of the diaper 10 and the

side edge portions

28 and 29 of the front and

rear waist regions

11 and 12 forming the side edge portion have the same configuration unless otherwise specified.

The upper regions 61 of the side edges 7, 8 of the diaper 10 have a 6-layer structure in which the

upper regions

28A, 29A of the front and

rear waist regions

11, 12 are joined to each other, the lower region 62 has a 4-layer structure in which the

lower regions

28B, 29B of the front and

rear waist regions

11, 12 have a 2-layer structure, and the intermediate region 63 has a 4-layer structure in which the

intermediate regions

28C, 29C of the front and

rear waist regions

11, 12 have a 2-layer structure. Therefore, the upper region 61 has a larger number of stacked sheets than the lower region 62 and the intermediate region 63 at both

side edge portions

7 and 8 of the diaper 10.

The dimension L1 in the longitudinal direction Y of both

side edge portions

7, 8 of the diaper 10 is 100 to 250mm, and the dimension in the longitudinal direction of each of the regions 61 to 63 is 20 to 40% of the dimension L1 in the longitudinal direction. In the present embodiment, the longitudinal dimension L1 in the longitudinal direction Y of both

side edge portions

7, 8 is 150mm, and each of the regions 61 to 63 has a dimension in the longitudinal direction Y with the total length being 3 equal parts. However, the

side edge portions

7 and 8 of the diaper 10 may be divided into 2 upper regions 61 and 2 lower regions 62 having a smaller number of sheets than the upper regions 61, and in this case, the

side edge portions

28 and 29 of the front and

rear waist regions

11 and 12 are similarly divided into 2

upper regions

28A and 29A and

lower regions

28B and 29B. Since the upper region 61 has a 6-layer structure, the mass ratio of the entire structure is relatively high, and is 110 to 140g/m ² On the other hand, the lower region 62 and the intermediate region 63 having a 4-layer structure have a mass of 50 to 80g/m ² 。

The seal portions 51 constituting the side seal regions 50 are arranged uniformly at both

side edge portions

7, 8 of the diaper 10. The total area of the side seal regions 50 (the total of the areas of the seal parts 51) is 40 to 200mm ² The circular sealing portions 51 are arranged in the longitudinal direction Y at a separation dimension (pitch) R1 of 0.5 to 4.0 mm. The separation dimension R1 can be appropriately adjusted depending on the areas of the seal portions 51, the required seal strength of the side seal region 50, and the like, but in order for the side seal region 50 to have an appropriate seal strength, the occupancy rate of the vertical dimension of the side seal region 50 (the total dimension of the vertical dimensions of the seal portions 51 excluding the separation dimension R1) with respect to the vertical dimension L1 of the

side edge portions

7 and 8 is preferably 20% or more. The dimension W1 in the transverse direction X of the seal portion 51 is 0.8 to 3.5mm, and may have a known shape such as a horizontally oblong shape, a vertically oblong shape, a triangular shape, a rectangular shape, a square shape, a rhombic shape, or a decorative shape such as a heart shape, a star shape, a ribbon shape, or the like, in addition to the substantially circular shape shown in the figure.

The area of the side seal region 50 (the total area of the seal portions 51) in the upper region 61, the middle region 63, and the lower region 62 is within a predetermined range at both

side edge portions

7, 8 of the diaper 10. However, in order to achieve the technical effects of the present invention, the areas of the side seal regions 50 of the respective regions 61 to 63 are preferably substantially the same within a predetermined range. In addition, as long as the area of the side seal region 50 of each region 61-63 is within a predetermined range, the shape, size, and separation dimension of the seal portion 51 located in each region 61-63 can be appropriately changed. Therefore, in each of the regions 61 to 63, even if the arrangement patterns of the seal portions 51 are different from each other, the areas of the side seal regions 50 are substantially the same.

When the diaper 10 is discarded, there are a plurality of modes for releasing the connection between the

side edge portions

28 and 29 of the front and

rear waist regions

11 and 12. For example, referring to fig. 7 (a), when the wearer or the wearer-assistant discards the diaper 10, the front and

rear waist regions

11 and 12 are gripped and pulled in the direction of separating from each other, and the openings 53 are formed in the side edge portions 28 of the front waist region 11 (or the side edge portions 29 of the rear waist region 12) along the outer peripheral edges of the seal portions 51, so that the front waist region 11 is separated from the rear waist region 12 (separation mode 1).

Referring to fig. 7 (b), when the wearer or the wearer assistant discards the diaper 10, the front and

rear waist regions

11 and 12 are gripped and pulled in the direction of separating from each other, and the side edge 28 of the front waist region 11 (or the side edge 29 of the rear waist region 12) is torn longitudinally along the inner edge of the side seal region 50 along the tear line K1 extending in the longitudinal direction Y, whereby the front waist region 11 is separated from the rear waist region 12 (separation 2).

Referring to fig. 7 c, when the wearer or the wearer-assistant discards the diaper 10, the front and

rear waist regions

11 and 12 are gripped and pulled in the direction of separating from each other, and the front waist region 11 is separated from the rear waist region 12 in a state where the interface between the front and

rear waist regions

11 and 12 of the seal 51 (the contact surface of the folded portions 18B and 21B of the outer sheet 18 and 21) is separated and a part of the seal 51 remains at both

side edge portions

28 and 29 of the front and rear waist regions 11 and 12 (separation mode 3).

In general, when the both

side edge portions

28 and 29 of the front and

rear waist regions

11 and 12 are separated from each other, it is considered that 2 or 3 of these separation methods are generated for each seal portion 51 intermittently arranged in the longitudinal direction Y, instead of separating by only one of the 1 st to 3 rd separation methods.

When the diaper has a region with a large number of sheets and a region with a small number of sheets at both side edge portions, the difference in tensile strength may cause a difference in rigidity in the vicinity of the boundary where the number of sheets changes when the side seal region is peeled off and the joining of both side edge portions in the front and rear waist regions, and may cause lateral tearing to occur outward or inward in the lateral direction X. When a lateral tear occurs laterally outward in the lateral direction X, a part of the diaper is separated and the tear has to be restarted from the torn part, and therefore the diaper cannot be smoothly gripped and torn. On the other hand, when a lateral tear is generated inward in the lateral direction X, there is a possibility that the excrement contained in the diaper may leak to the outside. In order to suppress the lateral tearing at the time of disposal, there is known a conventional technique of adjusting the bonding strength of the side seal region by the area, arrangement, pitch, and the like of the seal portion in accordance with the difference in the number of sheets, but the configuration of the manufacturing apparatus in the seal forming step of forming the side seal region has to be appropriately changed in accordance with the sheet configuration of the diaper to be manufactured, and the manufacturing load becomes large.

In the diaper 10 of the present invention, even if the number of sheets stacked in the upper region 61 and the lower region 62 at both side edge portions of the diaper 10 is larger and the bonding area and the bonding method of the side seal regions 50 are the same, there is no large difference in the seal strength of the upper region 61 and the seal strength of the lower region 62 in the side seal regions 50. Therefore, it is possible to suppress the occurrence of lateral tearing in the vicinity of the boundary between the regions where the number of sheets is different from one another, and to smoothly peel the side seal regions 50 from the waist opening 26 side toward the leg openings 27 at the side edge portions of the diaper 10.

Specifically, the maximum value of the seal strength of the upper region 61 in the side seal region 50 is less than 6 times the value of the average seal strength of the intermediate region 63 and the lower region 62. When the former is more than 6 times the latter, the difference in seal strength becomes large, and there is a possibility that lateral tearing may occur inward or outward in the lateral direction at both side edge portions of the diaper.

In the present invention, as described above, the reason why the seal strength of the upper region 61 and the seal strength of the lower region 62 do not differ much even if the arrangement of the seal portions 51 is the same is that i) the

outer layer sheets

18 and 22 of the upper region 61 are mainly constituted by the 1 st nonwoven fabric 71 made of the 1 st fibers (polyethylene fibers), the

inner layer sheets

17 and 21 are mainly constituted by the 2 nd nonwoven fabric 72 made of the 2 nd fibers (polypropylene fibers), ii) the tensile strength of the 1 st nonwoven fabric 71 in the transverse direction X is lower than the tensile strength of the 2 nd nonwoven fabric 72 in the transverse direction X, and Iii) the melting point of the 1 st fibers is lower than the melting point of the 2 nd fibers, and it can be said that i) to Iii) are necessary.

That is, since the

outer sheets

18 and 22 forming the outer surface of the diaper 10 have a relatively low tensile strength in the transverse direction X, even when the upper region 61 has a larger number of sheet layers than the intermediate region 63 and the lower region 62, the difference in tensile strength in the transverse direction X does not increase, and when the both

side edge portions

7 and 8 of the front and

rear waist regions

11 and 12 are longitudinally torn, it is difficult for the transverse direction tearing to occur. It can be said that the 1 st fibers have a relatively low melting point and therefore have excellent low-temperature sealability, but when the 1 st fibers are heated to a temperature equal to or higher than the melting point of the 2 nd fibers of the 2 nd nonwoven fabric 72 located on the inner surface side of the 1 st nonwoven fabric 71 in the sealing step at the time of production, the 1 st fibers become brittle and the sealability is lowered. This makes it easy for the

outer sheets

18 and 22 positioned on the outer surfaces to peel off from the sealing portion 51, and the sealing strength of the upper region 61 is relatively low. In order to reduce the sealing strength of the upper region 61, the melting point of the 1 st fibers of the 1 st nonwoven fabric 71 is preferably lower than the melting point of the 2 nd fibers of the 2 nd nonwoven fabric 72 by 20 ℃.

In the upper region 61, the number of the 1 st nonwoven fabric 71 is preferably larger than the number of the 2 nd nonwoven fabric 72. In the upper region 61, the 1 st nonwoven fabric 71 is positioned at least outside the 2 nd nonwoven fabric 72, and the number thereof is larger than that of the 2 nd nonwoven fabric 72, whereby even in the case where the upper region 61 has a multilayer structure of 3 layers or more, the tensile strength is relatively low, and it can be said that tearing of the sheet and peeling of the seal part 51 become easy.

The 1 st fibers of the 1 st nonwoven fabric 71 are continuous fibers extending in the transverse direction X. Since the 1 st nonwoven fabric 71 having a relatively low tensile strength is made of continuous fibers, even if the bonding at the bonding points (intersection points) caused by the fusion or adhesion of the fibers is released, the number of free ends included in the sheet is smaller than that of the short fibers, and thus it can be said that the sheet breakage is less likely to occur. Therefore, it can be said that when the side seal region 50 is peeled off at the time of disposal of the diaper 10, the lateral tear is less likely to occur than in the case of using short fibers.

Referring to fig. 7 (d), at least a part of the 1 st fibers 81 made of the continuous fibers of the 1 st nonwoven fabric 71 is cut in the sealing portion 51. The 1 st fibers 81, which are continuous fibers extending continuously in the transverse direction X, are cut in the seal forming step during manufacture, thereby forming a plurality of free ends 81a along the outer peripheral edge of the seal portion 51. By forming the plurality of free ends 81a along the outer peripheral edge of the seal portion 51, the front waist region 11 can be easily torn along the tear line K1, and as shown in fig. 7 (a), the openings 53 can be formed along the outer peripheral edge of the seal portion 51, and the side edge portions 28 of the front waist region 11 can be separated from the side edge portions 29 of the rear waist region 12. In order to facilitate tearing and peeling of the side seal region 50, it is preferable to cut 20% or more of the 1 st fibers 81 in the transverse seal portion 51.

< tensile Strength and elongation >

The following table 1 shows the measurement results of the tensile strength and elongation of the 1 st and 2

nd nonwoven fabrics

71, 72. The tensile strength and elongation of the sheet were measured using an Autograph type tensile tester (model AG-KN) manufactured by shimadzu corporation.

< method of measurement >

First, a sample having a length (longitudinal direction Y or transverse direction X) of 100mm × a width (transverse direction X or longitudinal direction Y) of 50mm was cut out from the 1 st and 2

nd nonwoven fabrics

71 and 72. Next, the sample was set on a tensile tester and stretched at a distance of 100mm between chucks and a tensile speed of 100 mm/min. The tensile strength of the specimen at 5%, 10% and 30% (5 mm, 10mm and 30 mm) elongation was measured as "tensile strength at 5%, tensile strength at 10% and tensile strength at 30% elongation", respectively. The maximum value of the tensile strength obtained during elongation is referred to as "maximum tensile strength", and the elongation at that time is referred to as "maximum elongation". The tensile strength and elongation of the 1 st and 2

nd nonwoven fabrics

71, 72 were measured in the machine direction Y and the transverse direction X, respectively. The machine direction Y is the MD direction which is the machine direction in the manufacture of the nonwoven fabric, and the cross direction X is the CD direction perpendicular to the machine direction.

[ Table 1]

Referring to Table 1, the 1 st nonwoven fabric 71 had a maximum tensile strength of 13.38N/50mm in the transverse direction X (MD direction) and 8.04N/50mm in the longitudinal direction Y (CD direction), while the 2 nd nonwoven fabric 72 had a maximum tensile strength of 58.89N/50mm in the transverse direction X and 15.87N/50mm in the longitudinal direction Y. The 1 st nonwoven fabric 71 has a maximum tensile strength of about 60% or less of the maximum tensile strength of the 2 nd nonwoven fabric 72 in the transverse direction X and the longitudinal direction Y, and therefore has a low tensile strength, and even if a plurality of layers are laminated in the upper region 61, the tensile strength as a whole does not increase, and the sheet can be easily torn at the time of disposal of the diaper 10. The maximum tensile strength of the 1 st nonwoven fabric 71 in the transverse direction X is lower than the maximum tensile strength of the 2 nd nonwoven fabric 72 in the longitudinal direction Y. This makes it possible to say that the 1 st nonwoven fabric 71 is easily torn at the start point when discarded.

The maximum elongation in the transverse direction X of the 1 st nonwoven fabric 71 was 87.5%, the maximum elongation in the machine direction Y was 137.24%, the maximum elongation in the MD of the 2 nd nonwoven fabric 72 was 58.89%, and the maximum elongation in the machine direction Y was 87.78%. Since the maximum elongation of the 1 st nonwoven fabric 71 is about 1.5 times the maximum elongation of the 2 nd nonwoven fabric 72 in both the transverse direction X and the longitudinal direction Y, it can be said that the entire upper region 61 having a relatively high mass is easily elongated to follow the body shape and the body motion when worn.

< average seal strength >

The following Table 2 shows the results of measuring the average seal strength of the diapers of examples 1 to 4 and comparative examples 1 to 8. The average seal strength was measured by an Autograph type tensile tester (model AG-KN) manufactured by Shimadzu corporation. The diapers of examples and comparative examples had 3-layer structures of an inner layer on the skin-facing surface side, an outer layer on the non-skin-facing surface side, and an intermediate layer between the inner and outer layers in the upper regions of both side edge portions of the front and rear waist regions, and 2-layer structures of the inner and outer layers in the intermediate region and the lower region. Both side edge portions of the front and rear waist regions are joined to each other via side seal regions in which a plurality of dot-like seal portions having the same shape and size are uniformly arranged, and the side seal regions are located in a region of 20mm width extending inward in the lateral direction X from both side edges of the diaper. The 1 st nonwoven fabric 71 is mainly a Polyethylene (PE) nonwoven fabric composed of polyethylene fibers, and the 2 nd nonwoven fabric 72 is mainly a polypropylene (PP) nonwoven fabric composed of polypropylene fibers.

In the diapers of examples 1 and 3 and comparative examples 1, 3, 5, and 7, the respective seal portions in the side seal regions had a circular shape with a diameter of 1.4mm, the respective seal portions were arranged in a row at intervals of 2.6mm in the longitudinal direction, and the total area of the side seal regions was 57.7mm ² . In the diapers of examples 2 and 4 and comparative examples 2, 4, 6, and 8, the respective seal portions of the side seal regions had a circular shape with a diameter of 1.4mm, the respective seal portions were arranged in a row at an interval of 1.6mm in the longitudinal direction, and the total area of the side seal regions was 76.64mm ² 。

< example 1 >

Outer layer: 1 st nonwoven fabric 71, intermediate layer: no. 2 nonwoven fabric 72, inner layer: no. 2 nonwoven fabric 72

< example 2 >

< example 3 >

Outer layer: 1 st nonwoven fabric 71, intermediate layer: 1 st nonwoven fabric 71, inner layer: no. 2 nonwoven fabric 72

< example 4 >

< comparative example 1 >

Outer layer: no. 2 nonwoven fabric 72, intermediate layer: no. 2 nonwoven fabric 72, inner layer: no. 1 nonwoven Fabric 71

< comparative example 2 >

< comparative example 3 >

Outer layer: no. 2 nonwoven fabric 72, intermediate layer: 1 st nonwoven fabric 71, inner layer: no. 1 nonwoven fabric 71

< comparative example 4 >

< comparative example 5 >

Outer layer: no. 2 nonwoven fabric 72, intermediate layer: no. 2 nonwoven fabric 72, inner layer: no. 2 nonwoven fabric 72

< comparative example 6 >

< comparative example 7 >

Outer layer: 1 st nonwoven fabric 71, intermediate layer: 1 st nonwoven fabric 71, inner layer: no. 1 nonwoven fabric 71

< comparative example 8 >

The seal strength was measured by the following method.

First, in the diaper of examples 1 to 4 and comparative examples 1 to 8, cut lines extending in the longitudinal direction were marked with a red pen at positions separated by 25mm from both side edges toward the inside in the transverse direction (the dimension in the longitudinal direction Y was 150 mm). The both side edge portions were cut along the dicing lines to obtain a measurement sample (25 mm. Times.150 mm) including the entire side seal region. Next, the upper edge of the front waist region and the upper edge of the rear waist region in the sample were fixed to chucks (with a distance between the chucks of 20 mm), and the side seal region was peeled in the 180 ° direction at a peeling speed of 500mm/min, and the average seal strength of the upper region, the middle region, and the lower region was measured. The average seal strength was measured 5 times, and the average value was defined as the average seal strength (N) D2, D3, D4 of each region. The maximum value of the measured seal strengths (the maximum value of the seal strength in the upper region) was defined as the maximum seal strength (N) D1.

[ Table 2]

Referring to table 2, in examples 1 to 4, the maximum value D1 of the seal strength of the upper side region was less than 6 times the value D4 of the average seal strength of the lower side region. Therefore, a large difference does not occur between the sealing strength of the upper region and the sealing strength of the lower region, and the side sealing region can be smoothly torn or peeled from the upper region toward the intermediate region and the lower region. In examples 1 and 2, D1/D4 was 6.0 or less. In comparative examples 1 and 2, as in examples 1 and 2, the values of D1/D4 were 11.62 and 17.5, respectively, although the 1 st nonwoven fabric had a 3-layer structure having 1 layer and 2 layers. This means that in examples 1 and 2, the 1 st nonwoven fabric was positioned in the outer layer, and thus the seal strength was reduced as compared with the case where the 2 nd nonwoven fabric was positioned in the outer layer.

In addition, when examples 3 and 4 and comparative examples 3 and 4 were compared, each had a 3-layer structure in which the 1 st nonwoven fabric was 2 layers and the 2 nd nonwoven fabric was 1 layer, but the values of D1/D4 in examples 3 and 4 were both 6.0 or less, whereas the value of D1/D4 in comparative example 3 was 17.1 and the value of D1/D4 in comparative example 4 was 18.48. This is believed to be due to the following reasons: in examples 3 and 4, similarly to examples 1 and 2, the 1 st nonwoven fabric mainly composed of the 1 st fibers having low tensile strength and low melting point was located in the outer layer, and the outer surfaces of both side edge portions of the front and rear waist regions were formed of the 1 st nonwoven fabric 71, and therefore the seal strength was lowered.

Fig. 8 (a) to (c) and fig. 9 (a) and (b) are views for explaining embodiments of side edge portions 28 of the front waist region 11 according to the 1 st to 5 th modifications shown as examples of other modifications of the diaper 10 of the present invention. The basic structure of the diaper 10 of each modification is the same as that of the diaper 10 of the present invention, and only the different structure will be described below. In the drawings, only one side edge portion 28 of the front waist region is described, but the other side edge portion 28 preferably has the same configuration. The side edge portion 29 of the rear waist region 12 may have this configuration instead of the side edge portion 28 of the front waist region 11, or both the

side edge portions

28, 29 of the front and

rear waist regions

11, 12 may have this configuration.

< modification 1 >)

Referring to fig. 8 (a), in the present modification, an intermediate sheet 91 made of a fibrous nonwoven fabric or a plastic film is disposed from the waist opening 26 side toward the leg openings 27 side. For convenience of explanation, the upper region 28A of the side edge portion 28 of the front waist region 11 has a 4-layer structure composed of the main body portion 18A of the outer sheet 18, the inner sheet 17, the intermediate sheet 91, and the folded portion 18B of the outer sheet 18, the intermediate region 28C has a 3-layer structure composed of the main body portion 18A of the outer sheet 18, the inner sheet 17, and the intermediate sheet 91, and the lower region 28B has a 2-layer structure composed of the main body portion 18A of the outer sheet 18 and the inner sheet 17.

According to the present modification, the correlation between the number of stacked sheets and the tensile strength in each of the regions 28A to 28C is upper region 28A > middle region 28C > lower region 28B. Therefore, while it is usual that the transverse direction tear is likely to occur in the vicinity of the boundary between the upper region 28A and the middle region 28C and in the vicinity of the boundary between the middle region 28C and the lower region 28B where the tensile strength changes, in the present embodiment, the 1 st nonwoven fabric 71 is located outside the upper region 28A where the number of layers is the largest, and the number of the 1 st nonwoven fabrics 71 is larger than the number of the 2 nd nonwoven fabrics 72 in the upper region 28A, so the tensile strength and the seal strength are relatively low. Therefore, the difference between the maximum seal strength of the upper region 28A having the largest number of layers and the average seal strength of the lower region 28B having the smallest number of layers is small, and the sheet can be smoothly torn and sealed from the waist opening 26 side to the leg openings 27 side, and the transverse tearing can be effectively suppressed.

< 2 nd modification example >

Referring to fig. 8 (B), according to the present modification, the main body portion 18A and the bent portions 18B of the outer-layer sheet 18 are located only in the upper region 28A. The upper region 28A has a 4-layer structure of the main body 18A of the outer sheet 18, the middle sheet 91 made of the 2 nd nonwoven fabric 72, the inner sheet 17, and the bent portion 18B, and the middle region 28C and the lower region 28B are formed only by the middle sheet 91 and the inner sheet 17. In the present modification, the upper region 28A has 2 layers more than the intermediate region 28C and the lower region 28B, but even in this case, the difference between the maximum seal strength of the upper region 28A and the average seal strength of the lower region 28B is not so large as to be smaller than 6 times, and therefore, no lateral tearing occurs in the vicinity of the boundary between the upper region 28A and the intermediate region 28C, and the intermediate region 28C and the lower region 28B, and both

side edge portions

28, 29 of the front and

rear waist regions

11, 12 can be smoothly separated.

< modification 3 >)

Referring to fig. 8 (c), according to the present modification, an outermost sheet 92 made of the 1 st nonwoven fabric 71 is disposed on the outer surface of the outer sheet 18A in the lower region 28B, except that the folded portion 18B of the outer sheet 18A and the intermediate sheet 91 are disposed only in the upper region 28A. The upper region 28A has a 4-layer structure of the main body portion 18A and the folded portion 18B of the outer sheet 18 made of the 1 st nonwoven fabric 71, and the intermediate sheet 91 and the inner sheet 17 made of the 2 nd nonwoven fabric 72 interposed therebetween, the intermediate region 28C has a 2-layer structure of the main body portion 18A of the inner sheet 17 and the outer sheet 18, and the lower region 28B has a 3-layer structure of the inner sheet 17, the main body portion 18A of the outer sheet 18, and the outermost sheet 92.

In the present modification, the upper region 28A > the lower region 28B > the intermediate region 28C are related to the number of stacked sheets and the tensile strength, but the upper region 28A and the intermediate region 28C include a plurality of the 1 st nonwoven fabrics 71, and a large difference in the tensile strength and the seal strength does not occur between the intermediate region 28C located therebetween in the longitudinal direction Y. Therefore, when the diaper 10 is discarded, the occurrence of lateral tearing in the vicinity of the boundary between the upper region 28A and the intermediate region 28C and in the vicinity of the boundary between the intermediate region 28C and the lower region 28B can be suppressed, and the both

side edge portions

28, 29 of the front and

rear waist regions

11, 12 can be smoothly separated from each other.

< modification example 4 >

Referring to fig. 9 (a), the seal portions 94 of the present modification are relatively small dot-like portions and are disposed at intervals so as not to overlap each other in the longitudinal direction Y and the lateral direction X. The diameter of the seal part 94 is 0.8 to 1.2mm, and the distances R2 and R3 are 1.4 to 1.8mm. Even if the seal portions 94 are relatively small, the required seal strength is exhibited as the entire side seal region 50 by arranging the seal portions in a so-called staggered manner, and the other seal portions 94 are positioned inside or outside the separated portion X of each seal portion 94 in the lateral direction, so that the lateral tearing of the separated portion can be effectively suppressed.

< modification 5 >)

Referring to fig. 9 (b), the sealing portion 95 of the present modification has a rectangular outer frame shape and has an elliptical non-sealing portion 96 inside thereof. By providing the sealing portions 95 with such a shape, the joint area can be reduced and the sealing strength can be adjusted to be relatively low, and the separation portion between the sealing portions 95 is relatively small, and the lateral tearing can be prevented.

The dimension L2 of the seal portion 95 in the longitudinal direction Y is 3.0 to 5.0mm, the dimension W1 of the transverse direction X is 1.5 to 3.0mm, the dimension W2 of the non-seal portion 96 in the transverse direction X is 0.5 to 1.5mm, the dimension L3 of the longitudinal direction Y is 2.0 to 3.0mm, and the pitch R4 is 0.5 to 1.5mm.

All the features that can be understood by those skilled in the art from the description of the present specification, drawings, and claims may be combined with 1 or more other features independently or arbitrarily, even if they are described in combination with only specific other features.

Description of the reference numerals

10. Underwear-type wearing article (Disposable underwear-type diaper)

11. Front waist region (No. 1 waist region or No. 2 waist region)

12. Rear waist region (No. 1 waist region or No. 2 waist region)

13. Crotch region

17. Inner layer sheet material (inner layer)

18. Outer sheet material (outer layer)

Main body of 18A outer layer sheet

Bent part of 18B outer sheet

21. Inner layer sheet material (inner layer)

22. Outer sheet material (outer layer)

Main body of 22A outer layer sheet

Bent part of 22B outer sheet

28. Side edge part of front waist region

28A Upper side region (region 1)

28B lower region (2 nd region)

28C middle zone (zone 2)

29. Side edge part of rear waist region

29A Upper side region (region 1)

29B lower region (region 2)

29C middle zone (zone 2)

50. Side seal area

51. Sealing part

71. No. 1 nonwoven fabric

72. No. 2 nonwoven fabric

91. Middle sheet (middle layer)

81. No. 1 fiber

In the X transverse direction

Y longitudinal direction

Claims

1. A pants-type wearing article having a longitudinal direction and a transverse direction and comprising a 1 st waist region, a 2 nd waist region, a waist opening defined by overlapping both side edge portions of the 1 st waist region and the 2 nd waist region with each other and joining the same via side seal regions, and a pair of leg openings, the side seal regions having a plurality of seals discontinuously extending in the longitudinal direction,

at least one side edge portion of the 1 st waist region and the 2 nd waist region includes a 1 st region located on the waist opening side and a 2 nd region located on the leg opening side,

in the 1 st region and the 2 nd region, the area of the side seal region is within a prescribed range,

the number of stacked sheets forming the 1 st region is larger than the number of stacked sheets forming the 2 nd region,

the 1 st region includes a 1 st nonwoven fabric mainly composed of 1 st fibers on the outer surface side of the wearing article and a 2 nd nonwoven fabric mainly composed of 2 nd fibers on the inner surface side of the wearing article,

a tensile strength in the transverse direction of the 1 st nonwoven fabric is lower than a tensile strength in the transverse direction of the 2 nd nonwoven fabric, and a melting point of the 1 st fiber is lower than a melting point of the 2 nd fiber,

the 1 st fibers are mainly polyethylene fibers composed of continuous fibers extending in the transverse direction, and the 1 st nonwoven fabric is a spunmelt nonwoven fabric,

the 2 nd fibers are predominantly polyolefin fibers,

the maximum value of the seal strength of the upper region among the side seal regions is less than 6 times the value of the average seal strength of the intermediate region and the lower region.

2. The article of wear of claim 1,

the 2 nd region includes the 1 st nonwoven fabric and the 2 nd nonwoven fabric.

3. The article of wear of claim 1,

at least a part of the 1 st fibers is cut in the vicinity of the outer periphery of the seal portion.

4. The article of wear of claim 1 or 2,

the tensile strength in the transverse direction of the 1 st nonwoven fabric is less than the tensile strength in the longitudinal direction of the 2 nd nonwoven fabric.