AU2016225466A1

AU2016225466A1 - Disposable diaper

Info

Publication number: AU2016225466A1
Application number: AU2016225466A
Authority: AU
Inventors: Takuya Miyama; Satoru Sakaguchi; Yasuhiro Yamanaka
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2015-02-27
Filing date: 2016-01-29
Publication date: 2017-08-17
Anticipated expiration: 2036-01-29
Also published as: KR102469156B1; MY179825A; AU2016225466B2; KR20170122737A; WO2016136388A1; CN107249528A; JP2016158753A; CN107249528B; JP5956003B1

Abstract

In planar view, this disposable diaper (10) has a central line (O) which, running in the longitudinal direction (L) of a pair of pieces of fastening tape (90), overlaps with an elastic waist part (85) and does not overlap with an absorbent body (40). The length (W1) of the elastic waist part (85) in the width direction (W) is longer than the length (W2) of the absorbent body (40) in the width direction (W). The elongation rate of a region (A) of the elastic waist part (85) positioned to the outside of the absorbent body (40) in the width direction (W) is different from the elongation rate of a region (B) of the elastic waist part (85) positioned to the inside of the absorbent body (70) in the width direction (W).

Description

Description_UC-1048-PCT 1 DESCRIPTION DISPOSABLE DIAPER [TECHNICAL FIELD] [0001]

The present invention relates to a disposable diaper.

[BACKGROUND ART] [0002]

Conventionally, there has been a known technology of providing a waistline stretch unit that stretches and contracts in a width direction around a waist of a wearer to maintain fit around the waist of the wearer in a tape-type disposable diaper. [CITATION LIST] [0003] [PATENT LITERATURE]

Patent Literature V- JPH10-225481 A [SUMMARY OF INVENTION] [TECHNICAL PROBLEM] [0004]

However, in the above-described conventional disposable diaper, stretching of the waistline stretch unit is hindered due to rigidity of an absorber. Thus, there has been a problem that the disposable diaper may not be tightly fit around the waist of the wearer and a leakage of excrement from dorsal side of the wearer is induced.

[0005]

In this regard, the invention has been conceived in view of the above-mentioned problem, and an object of the invention is to provide a tape-type disposable diaper capable of enhancing a fit around the waist of the wearer.

[SOLUTION TO PROBLEM] [0006]

In summary, a first aspect of the present invention is a disposable diaper having a front waistline region! a rear waistline region! a crotch region positioned between the front waistline region and the rear waistline region! a longitudinal direction extending from the front waistline region to the rear waistline region! a width direction orthogonal to the longitudinal direction a pair of fastening tapes which extends along the width direction in the rear waistline region and is fastened to the front waistline region! an absorber which straddles the crotch region and extends toward at least one of the front waistline region and the rear waistline region! and

Description_UC-1048-PCT 2 a waist stretch unit which is disposed between the pair of fastening tapes and stretches and contracts in the width direction, wherein a center line of the pair of fastening tapes in the longitudinal direction overlaps the waist stretch unit and does not overlap the absorber in a plan view of the disposable diaper, a length of the waist stretch unit in the width direction is longer than a length of the absorber in the width direction, and an elongation rate of a region positioned at an outer side of the absorber in the width direction in the waist stretch unit is different from an elongation rate of a region positioned at an inner side of the absorber in the width direction in the waist stretch unit. [BRIEF DESCRIPTION OF DRAWINGS] [0007]

Fig. 1 is a developed plan view of a disposable diaper of the embodiment.

Fig. 2 is a cross sectional view of the disposable diaper taken along the line Fl-Fl shown in Fig. 1.

Fig. 3 is a cross sectional view of the disposable diaper taken along the line F2-F2 shown in Fig. 1.

Figs. 4(a) and 4(b) are schematic views showing the manners the disposable diaper of the embodiment is worn by a wearer. Fig. 4(a) shows a state in which fastening tapes are fastened to a front waistline region while the wearer is lying on one's back; Fig. 4(b) shows a state in which the fastening tapes are fastened to the front waistline region while the wearer is up.

[DESCRIPTION OF EMBODIMENTS] [0008]

Embodiments of a disposable diaper 10 of the present invention will now be described with reference to the drawings. Note that, in the following description of the drawings, the same or similar components are given the same or similar reference number. It should be appreciated that the drawings are for schematic depiction only and the dimensions therefor are not to scale.

[0009]

Thus, specific dimensions and the like should be determined taking the following description into consideration. Note that, some dimensional relation or scale can be different between the drawings.

[0010] (l) Overall schematic configuration of disposable diaper

Fig. 1 is a developed plan view of a disposable diaper 10 of the embodiment. Fig. 2 is a cross sectional view of the disposable diaper taken along the line Fl-Fl shown in Fig. 1. Fig. 3 is a cross sectional view of the disposable diaper taken along the line F2-F2 shown in Fig. 1. The developed plan view shown in Fig. 1 illustrates a state in which

Description_UC-1048-PCT 3 elastic elements of leg stretch units 75 and leg side stretch units 80 are extended to such extent that no wrinkles are formed in components of the disposable diaper, such as a topsheet 50, side flaps 70, and the like.

[0011]

As illustrated in Fig. 1, the disposable diaper 10 has a front waistline region 20, a crotch region 25, and a rear waistline region 30. The front waistline region 20 comes in contact with the front waistline region (i.e., ventral portion) of the wearer. The rear waistline region 30 comes in contact with the rear waistline region (i.e., dorsal unit) of the wearer. The crotch region 25 is positioned between the front waistline region 20 and the rear waistline region 30.

[0012]

Further, a pair of leg openings 35 is formed in the disposable diaper 10. The leg openings 35 are disposed along the outside edges (the outer end in the longitudinal direction) of the disposable diaper, respectively, and will be disposed encircling the legs of the wearer when the disposable diaper is worn by the wearer.

[0013]

Note that, in the embodiment, the direction from the front waistline region 20 to the rear waistline region 30 is referred to as a longitudinal direction L, and the direction orthogonal to the longitudinal direction L is referred to as a width direction W.

[0014]

The disposable diaper 10 has an absorber 40. The absorber 40 has an absorbent core 40a and a core wrap 40b. The absorbent core 40a is straddles the crotch region 25 and extends from the crotch region 25 toward at least one of the front waistline region 20 and the rear waistline region 30.

[0015]

The absorbent core 40a is the same as for conventional disposable diapers and can be suitably formed using well-known elements and materials such as comminuted pulp, high absorbent polymer, or the like. The absorbent core 40a is encased by a sheet-like core wrap 40b. The core wrap 40b is a sheet that covers the absorbent core 40a. The rear edge of the absorbent core and the rear edge of the core wrap are substantially aligned. More specifically, the distance between the rear edge of the absorbent core and the rear edge of the core wrap is 5 mm or less.

[0016]

The absorbent core 40a is provided with a lower basis weight region 110 where a basis weight is lower than a basis weight in the other parts of the absorbent core 40a. The lower basis weight region 110 is positioned in the widthwise center of the rear edge of the absorbent core 40a. The width of the lower basis weight region 110 along the width direction W is gradually widened toward the rear edge of the absorbent core 40a. More specifically, the lower basis weight region 110 has a wedged shape in plan view of the

Description_UC-1048-PCT 4 disposable diaper 10.

[0017]

As illustrated in Fig. 2 and 3, a topsheet 50 that is permeable to liquid is provided on the top side (i.e., skin-facing surface side) of the absorber 40. Further, a backsheet 60a that is impermeable to liquid is provided on the back side (i.e., non-skin-facing surface side) of the absorber 40. On the back side of the backsheet 60a provided is an exterior sheet 60.

[0018]

As illustrated in Fig. 1 and 2, a side flap 70 is provided along each of the outside edges (outer ends in the width direction) of the absorber 40. The side flap 70 is disposed across the front waistline region 20, the crotch region 25, and the rear waistline region 30, and is disposed outward relative to the absorber 40 in the width direction.

[0019]

The side flap 70 is made of one or more, such as more than two, laminated nonwoven fabrics. As illustrated in Fig. 2, the side flap 70 is positioned toward the skin-facing surface relative to the absorbent core 40a, and extends outward relative to the absorbent core 40a in the width direction.

[0020]

As illustrated in Fig. 2, an inside edge (an inner end in the width direction W) of the side flap 70 covers the absorbent core 40a, and an outside edge of the side flap 70 is disposed at an outer side of the absorbent core 40a in the width direction W.

[0021]

As illustrated in Fig. 1, each one of the pair of side flaps 70 is provided with a leg stretch unit 75, disposed inward relative to the respective leg opening 35 in the width direction and being stretchable in the longitudinal direction L. The leg stretch unit 75 may have any configuration capable of stretching the leg opening 35 in the longitudinal direction; for example, the leg stretch unit 75 may be disposed along the leg opening 35 or part of the leg stretch unit 75 may be disposed in an inclined manner relative to the leg opening 35.

[0022]

Here, as illustrated in Fig. 1, the pair of leg stretch units 75 may be configured to widen outward in the width direction W toward the rear waistline region 30.

[0023]

Furthermore, as illustrated in Fig. 1, a pair of leg side stretch units 80, extending in the longitudinal direction L, is provided inward of the pair of leg stretch units 75 in the width direction. The leg side stretch units 80 are disposed are provided at inside ends in the product width wise direction of the side flap 70, and are rising-type stretching gathers.

[0024]

Furthermore, the disposable diaper 10 includes a crotch stretch unit 200,

Description_UC-1048-PCT 5 disposed in a region overlapping the absorber in the crotch region 25. It is configured such that, when the disposable diaper is worn, the crotch stretch unit 200 can maintain a flat shape as compared to the other portions of the absorber 40 at the part of the crotch region 25. The crotch stretch unit 200 is configured to be stretchable at least in the longitudinal direction L or the width direction W.

[0025]

As illustrated in Fig. 1, a first notch 115 and a second notch 125 are formed in the absorbent core 40a in the crotch region. The first notch 115 and the second notch 125 are slits formed in the absorber 40. Absorbent material is absent in these slits. The first notch 115 and the second notch 125 have a notched shape extending inward from the outside edge of the absorbent core 40a in the width direction.

[0026]

The disposable diaper 10 may not have the crotch stretch unit 200, the first notch 115, and the second notch 125.

[0027]

Fastening tapes 90 are provided as a pair and extending along the width direction W in the rear waistline region 30. Fastening tapes 90 holds the disposable diaper 10 onto the body of the wearer by being fastened to the non-skin contact surface of the front waistline region 20.

[0028]

The fastening tapes 90 are provided in each of the pair of side flaps 70 at a region corresponding to the rear waistline region 30. Each of the fastening tapes 90 includes a base sheet 91 connected to the side flap 70, and a hook sheet 92 that is fixed to the base sheet 91 and provided with a plurality of engagement elements in the form of engagement hooks (not shown). The hook sheet 92 is a region where the engagement elements are disposed.

[0029]

Here, as illustrated in Fig. 1, the absorber 40 (or the absorbent core 40a) may be disposed at an inner side of inner edge 92E1 of the hook sheet 92 in the longitudinal direction L.

[0030]

Target units 95 are disposed on the non-skin-facing surface of the exterior sheet 60 in the front waistline region 20. The target units 95 are configured to be hooked by the engagement hooks of the fastening tapes, and function as the loop in a hook-loop fastening system.

[0031]

For the target units, an air-through nonwoven fabric can be employed, for example. Alternatively, the disposable diaper may be configured without the target units but the fastening tapes 90 may be otherwise fastened to the exterior sheet 60 in the

Description_UC-1048-PCT 6 front waistline region.

[0032]

Furthermore, as illustrated in Fig. 1 and 2, a waist stretch unit 85 is disposed between the pair of fastening tapes 90 in the width direction and being stretchable in the width direction W. The waist stretch unit 85 contracts between the fastening tapes 90 in the width direction.

[0033]

In the embodiment, the waist stretch unit 85 is formed of a stretchable sheet. Note that, the concept of the waist stretch unit 85 includes a region that actually stretches and contracts in the width direction but excludes a region provided with the stretchable sheet in a state in which its stretching will not be effected. Hence, an outside edge of the waist stretch unit, which will be discussed later, refers to an outside edge of a stretching region but not to an outside edge of the stretchable sheet.

[0034]

In the embodiment, a stretchable film having a basis weight of 20-45 g/m2 is used for the waist stretch unit 85. The waist stretch unit 85, however, may be formed of other structure(s) such as a plurality of rubber threads or the like. The waist stretch unit 85 is stretched to a length of a predetermined ratio to a length in its uncontracted state (natural state), and then adhesively bonded to the exterior sheet 60 by a hot melt adhesive, heat processing, or the like.

[0035]

The waist stretch unit 85 extends from a center of the disposable diaper 10 in the width direction W toward both outer sides in the width direction W and includes a continuous sheet extending in the width direction W. A rear edge (an outer end in the longitudinal direction L) 85E2 of the waist stretch unit 85 is positioned at a top side of a rear edge 10E2 of the disposable diaper 10. The rear edge 85E2 of the waist stretch unit 85 may correspond to the rear edge 10E2 of the disposable diaper 10.

[0036]

In addition, a front edge 85E1 of the waist stretch unit 85 is positioned at a top side of a rear edge 40E2 of the absorber 40 (or a rear edge of the absorbent core 40a and a rear edge of the core wrap 40b) and at a rear side of a rear edge 75 E2 of the leg stretch unit 75. Therefore, in the plan view of the disposable diaper 10, at least a portion of the waist stretch unit 85 overlaps the absorber 40 (or the absorbent core 40a).

[0037]

Here, a thickness of the absorber 40 in a region in which the absorber 40 overlaps the waist stretch unit 85 is thinner than a thickness of the absorber 40 in the other region.

[0038]

In addition, the waist stretch unit 85 is configured to straddle the rear edge of the

Description_UC-1048-PCT 7 absorber 40 (or the rear edge of the absorbent core 40a and the rear edge of the core wrap 40b) and extends to a rear side of the rear edge of the absorber 40 (or the rear edge of the absorbent core 40a and the rear edge of the core wrap 40b).

[0039]

An outside edge 85WO of the waist stretch unit 85 is positioned inward of the inside edge (the inner end in the width direction) of the fastening tape in the width direction. The waist stretch unit 85 and the fastening tape 90 are spaced apart in the width direction.

[0040]

As illustrated in Fig. 1, the waist stretch unit 85 has a first region 851 which extends inward in the width direction W from both outside edges 85WO of the waist stretch unit 85, a second region 852 which extends inward in the width direction W from an inside edge 851WI of the first region 851, and a third region 853 which extends inward in the width direction W from an inner edge 852WI of the second region 852.

[0041]

The first regions 851, the second regions 852, and the third region 853 are contiguous in the width direction. Hence, a non-stretch region that does not stretch in the width direction is not provided between the first region 851 and the second region 852 and between the second region 852 and the third region 853. Further, the inner edges 851WI of the first regions 851 coincide with outside edges 852WO of the second regions 852, and the inside edges 852WI of the second regions 852 coincide with outside edges 853WO of the third region 853.

[0042]

The first region 851, the second region 852, and the third region 853 are configured such that an elongation rate in the width direction W is different among the regions. Specifically, an elongation rate of the second region 852 in the width direction W is lower than an elongation rate of the first region 851 in the width direction W. In addition, an elongation rate of the third region 853 in the width direction W is higher than an elongation rate of the second region 852 in the width direction W.

[0043]

In addition, the elongation rate of the first region 851 in the width direction W and the elongation rate of the third region 853 in the width direction W may have a relationship in which the elongation rates are the same or one of the elongation rates is higher than the other one. Preferably, the elongation rate of the third region 853 in the width direction W is higher than the elongation rate of the first region 851 in the width direction W.

[0044]

An outside edge 851WO of the first region 851 is positioned at an outer side of the outside edge of the absorbent core 40a in the width direction W. An inside edge 851WI of

Description_UC-1048-PCT 8 the first region 851 is positioned at inner side of the outside edge of the absorbent core 40a in the width direction W. Therefore, the first region 851 is disposed to straddle the outside edge of the absorbent core 40a.

[0045]

At least a portion of the first region 851 may be positioned at an outer side of the absorbent core 40a in the width direction W, an inside edge of the first region 851 may be positioned at an outer side of the outside edge of the absorbent core 40a in the width direction W, and the inside edge of the first region 851 may correspond to the outside edge of the absorbent core 40a.

[0046]

The second region 852 is positioned between the first region 851 and the third region 853. The second region 852 is preferably positioned at an inner side of the outside edge of the absorbent core 40a in the width direction W.

[0047]

The third region 853 is disposed to straddle the center of the disposable diaper 10 in the width direction W. The third region 853 preferably overlaps at least a portion of the lower basis weight region 110 in the plan view of the disposable diaper 10.

[0048]

In the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 may be symmetric or asymmetric with respect to a center line passing through the center of the disposable diaper 10 in the width direction W and extending in the longitudinal direction L.

[0049]

For example, both right and left first regions 851 may straddle the outside edge of the absorbent core 40a, and one of the first regions 851 may straddle the outside edge of the absorbent core 40a. In addition, both right and left second regions 852 may be disposed at an inner side of the outside edge of the absorbent core 40a in the width direction W, and one of the second regions 852 may be disposed at the inner side of the outside edge of the absorbent core 40a in the width direction W.

[0050]

In addition, in the disposable diaper 10 according to the present embodiment, a region having a lower elongation rate than the elongation rate of the first region 851 may be provided at an outer side of the first region 851 in the width direction W.

[0051]

As illustrated in Fig. 3, the waist stretch unit 85 is positioned at the non-skin contact surface side of the absorbent core 40a. In the present embodiment, the waist stretch unit 85 is disposed between the exterior sheet 60 and the backsheet 60a.

[0052]

However, in a configuration in which the core wrap 40b extends to an outer side

Description_UC-1048-PCT 9 of the absorbent core 40a in the longitudinal direction L, the waist stretch unit 85 may be disposed between the core wrap 40b and the backsheet 60a or the exterior sheet 60.

[0053] A position of the waist stretch unit 85 is not particularly restricted. In addition, in a region in which the absorber 40 is not disposed, the waist stretch unit 85 may be disposed between the side flap 70 and the backsheet 60a or the exterior sheet 60 as illustrated in Fig. 2.

[0054]

As illustrated in Fig. 1, in the plan view of the disposable diaper 10, a center line O of the pair of fastening tapes 90 in the longitudinal direction L overlaps the waist stretch unit 85 and does not overlap the absorber 40.

[0055]

In addition, a length W1 of the waist stretch unit 85 in the width direction W is longer than a length W2 of the absorber 40 in the width direction W (or a length of the absorbent core 40a in the width direction W).

[0056]

Further, an elongation rate of a region A positioned at an outer side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85 is different from an elongation rate of a region B positioned at an inner side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85.

[0057]

That is, as illustrated in Fig. 1, the region A is positioned at an outer side of a virtual line VL1 in the width direction W, and the region B is positioned at an inner side of the virtual line VL1 in the width direction W. Here, the virtual line VL1 is a line extending from the outside edge of the absorber 40 in a portion of the absorber 40 having a longest length in the width direction W to the rear edge 10E2 of the disposable diaper 10 along the longitudinal direction L.

[0058]

For example, the elongation rate of the region A positioned at the outer side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85 may be larger than the elongation rate of the region B positioned at the inner side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85 or smaller than the elongation rate of the region B positioned at the inner side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85.

[0059]

In addition, as illustrated in Fig. 1, in the plan view of the disposable diaper 10, the waist stretch unit 85 and the pair of leg stretch units 75 may not overlap each other.

Description_UC-1048-PCT 10 [0060]

Meanwhile, as illustrated in Fig. 1, in the plan view of the disposable diaper 10, the waist stretch unit 85 and the pair of leg side stretch units 80 may overlap each other.

[0061]

In addition, as illustrated in Fig. 1, the inner edge (front edge) 85E1 of the waist stretch unit 85 in the longitudinal direction L may be disposed at an inner side of the inner edge 92El of the hook sheet 92 in the longitudinal direction L.

[0062]

Further, as illustrated in Fig. 1, the rear edge 85E2 of the waist stretch unit 85 may be disposed at an outer side of the outer edge 92E2 of the hook sheet 92 in the longitudinal direction L.

[0063]

Even though the waist stretch unit 85 is configured to stretch and contract in the width direction W in the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 may be configured to stretch and contract in the width direction W and the longitudinal direction L.

[0064]

In addition, the waist stretch unit 85 and the absorber 40 are bonded by an adhesive. The adhesive that bonds the waist stretch unit 85 and the absorber 40 together is disposed such that a plurality of rows is continuous in the longitudinal direction L and the respective rows overlap each other in the width direction W.

[0065]

Specifically, examples of a configuration of the adhesive may include a configuration in which a plurality of rows of spiral shapes continuing in the longitudinal direction L is disposed and the rows overlap each other in the width direction W, a configuration in which a plurality of rows of corrugated shapes having amplitudes in the width direction W and continuing in the longitudinal direction L is disposed and the rows overlap each other in the width direction W, etc.

[0066]

In the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 and the absorbent core 40a are not directly bonded together and are indirectly bonded through the backsheet 60a and the core wrap 40b.

[0067]

An adhesive that bonds the waist stretch unit 85 and the backsheet 60a together, an adhesive that bonds the backsheet 60a and the core wrap 40b together, and an adhesive that bonds the core wrap 40b and the absorbent core 40a together are preferably disposed such that a plurality of rows is continuous in the longitudinal direction L and the respective rows overlap each other in the width direction W.

[0068]

Description_UC-1048-PCT 11

An "elongation rate" in the present specification refers to a degree of elongation and is performed by the following measurement method.

[0069]

Firstly, when the disposable diaper 10 is enclosed in a package, etc., the disposable diaper 10 is taken out from the package.

[0070]

Secondly, a region in which an elastic sheet included in the waist stretch unit 85 is disposed is cut to prepare a sample to be measured. A state in which such a sample is left in an atmosphere of 20°C ± 2°C and a relative humidity of 60% ± 5% RH for 24 hours is referred to as a "natural state".

[0071]

Thirdly, in such a natural state, points (marks) are intermittently put along the width direction W at intermediate position between an edge (front edge) at the absorbent core 40a side of the elastic sheet and an edge (rear edge) at the waist opening side of the elastic sheet, that is, at an intermediate position in the longitudinal direction L of the elastic sheet. Referring to such points, using a center of the elastic sheet in the width direction W as a reference point, the points (marks) are put from the reference point to an outside edge of the sample of the elastic sheet at an interval of 5 mm on right and left sides in the width direction W.

[0072]

Fourthly, a distance between adjacent points is measured. The distance is set as a length in the natural state (which is 5 mm since marks are put at the interval of 5 mm).

[0073]

Fifthly, the distance between the marks is measured in a stretched state in which wrinkles caused by the elastic member may not be visually recognized on the elastic sheet from the natural state.

[0074]

Sixthly, an elongation rate is calculated by an equation of an elongation rate (times) of each part = (a distance between marks in an elongated state) / (a distance between marks in a natural state).

[0075] (2) Method of manufacturing disposable diaper 10

Next, a description will be given of an example of a method of manufacturing the disposable diaper 10 according to the present embodiment. An existing method may be used as a method which is not described in the present embodiment. In addition, the manufacturing method described below is an example, and manufacturing may be performed by another manufacturing method. The method of manufacturing the disposable diaper 10 includes at least a component forming process, a component placing process, a leg opening forming process, and a cutting process.

Description_UC-1048-PCT 12 [0076]

In the component forming process, a component included in the disposable diaper 10 is formed. Specifically, for example, an absorptive material may be stacked to mold the absorber 40, or the fastening tape 90 is formed.

[0077]

In the component placing process, a component included in the disposable diaper 10 is placed on a web included in the backsheet 60a. Examples of the component include the elastic sheet included in the waist stretch unit 85, another web such as a web included in the topsheet 50, a leakage-preventing sheet, the absorber 40, the leg stretch unit 75, etc.

[0078] A method below is given as an example of a method of changing the elongation rate of the waist stretch unit 85.

[0079]

The waist stretch unit 85 is stretched by a gear in the width direction W before the waist stretch unit 85 is pasted on the backsheet 60a, etc.

[0080]

At the time of stretching by the gear, gear stretching is weakened in a region in which the elongation rate is decreased (for example, the second region 852). Gear stretching is strengthened in a region in which the elongation rate is increased (for example, the first region 851 or the third region 853). The strength of gear stretching may be adjusted by changing a depth of a projection of the gear, a pitch of the projection of the gear, or the number of times of gear stretching. An elongation rate of a strongly stretched region is relatively high, and an elongation rate of a weakly stretched region is relatively low.

[0081]

In the leg opening forming process, the topsheet 50, the exterior sheet 60, and the backsheet 60a are cut. In this way, the leg openings 35 disposed around legs of the wearer are formed.

[0082]

In the cutting process, a continuous body in which the topsheet 50, the backsheet 60a, the absorber 40, etc. are disposed is cut into a size of one product along the width direction W. In this way, the disposable diaper 10 is manufactured.

[0083] (3) Effects

In the disposable diaper 10 according to the present embodiment, the length Wl of the waist stretch unit 85 in the width direction W is longer than the length W2 of the absorber 40 (or a length of the absorbent core 40a) in the width direction W. Further, in the plan view of the disposable diaper 10, the center line O of the fastening tapes 90 in

Description_UC-1048-PCT 13 the longitudinal direction L overlaps the waist stretch unit 85 and does not overlap the absorber 40. Therefore, it is possible to solve the problem that stretching of the waist stretch unit 85 is hindered due to rigidity of the absorber 40 when a wearing assistant pulls the fastening tape 90 at the time of wearing the disposable diaper 10, and thus it is possible to tightly fit the disposable diaper 10 around the waistline of the wearer.

[0084]

Figs. 4(a) and 4(b) schematically illustrate states in which the disposable diaper 10 is worn by the wearer. Fig. 4(a) corresponds to a state in which the fastening tape 90 is fastened to the front waistline region 20 while the wearer is lying on one's back, and Fig. 4(b) corresponds to a state in which the fastening tape 90 is fastened to the front waistline region 20 while the wearer is up.

[0085]

When the tape-type disposable diaper 10 is worn on the wearer, the wearing assistant puts the dorsal portion of the wearer on the rear waistline region 30 of the disposable diaper 10, pulls the fastening tape 90 outward in the width direction W, and fastens the fastening tape 90 to the front waistline region 20. As illustrated in Fig. 4(a), in such a case, a body pressure of the wearer is applied to the rear waistline region 30 of the disposable diaper 10.

[0086]

In such a case, a force generated when the wearing assistant pulls the fastening tape 90 outward in the width direction W is not transmitted to the region B positioned at the inner side of the absorber 40 (absorbent core 40a) in the width direction W in the waist stretch unit 85. Thus, there is a possibility that a gap is formed between the wearer and the disposable diaper 10 when the wearer is raised after the disposable diaper 10 is worn.

[0087]

Here, in the case in which the disposable diaper 10 according to the present embodiment is configured such that the elongation rate of the region A positioned at the outer side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85 is larger than the elongation rate of the region B positioned at the inner side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85, the region B is pulled and stretched in the width direction W by the region A having a larger elongation rate than that of the region B when the wearer is raised. Thus, it is possible to solve the problem that there is a possibility that a gap is formed between the wearer and the disposable diaper 10.

[0088]

On the other hand, in the case in which the disposable diaper 10 according to the present embodiment is configured such that the elongation rate of the region A positioned at the outer side of the absorber 40 (or the absorbent core 40a) in the width direction W in

Description_UC-1048-PCT 14 the waist stretch unit 85 is smaller than the elongation rate of the region B positioned at the inner side of the absorber 40 (or the absorbent core 40a) in the width direction W in the waist stretch unit 85, the amount of elongation increases in the width direction W of the region A even when the wearing assistant pulls the fastening tape 90 with a weak force at the time of mounting the disposable diaper 10 on the wearer. Thus, it is possible to solve the problem that there is a possibility that the region B is pulled and stretched in the width direction W by the region A and a gap is formed between the wearer and the disposable diaper 10 when the wearer is raised after the disposable diaper 10 is worn.

[0089]

Further, in the plan view of the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 and the pair of leg stretch units 75 are configured not to overlap each other. Thus, it is possible to avoid a situation in which the waist stretch unit 85 is pulled inward in the longitudinal direction L by following movement of a leg of the wearer and does not tightly fit around the waist of the wearer after the disposable diaper 10 is worn.

[0090]

Further, in the plan view of the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 and the pair of leg side stretch units 80 are configured to overlap each other. Thus, it is possible to suppress a situation in which the disposable diaper 10 is raised toward the waist stretch unit 85 and a body of the wearer and the disposable diaper 10 are separated from each other.

[0091]

Further, in the plan view of the disposable diaper 10 according to the present embodiment, the waist stretch unit 85 and the absorber 40 (or the absorbent core 40a) overlap each other, and the thickness of the absorber 40 (or the absorbent core 40a) in a region overlapping the waist stretch unit 85 is thinner than the thickness of the absorber 40 (or the absorbent core 40a) in another region. Thus, the absorber 40 (or the absorbent core 40a) is pressed by the waist stretch unit 85, and thus it is possible to improve a fit to the wearer.

[0092]

Further, in the disposable diaper 10 according to the present embodiment, the absorber 40 (or the absorbent core 40a) is disposed at the inner edge 92E1 of the hook sheet 92 in the longitudinal direction L. Thus, it is possible to more reliably reduce an influence of a force, which is generated when the fastening tape 90 is pulled outward in the width direction W, on the region B.

[0093]

Further, in the disposable diaper 10 according to the present embodiment, the inner edge (front edge) 85E1 of the waist stretch unit 85 in the longitudinal direction L is disposed at the inner side of the inner edge 92E1 of the hook sheet 92 in the longitudinal

Description_UC-1048-PCT 15 direction L, and the outer edge (rear edge) 85E2 of the waist stretch unit 85 in the longitudinal direction L is disposed at the outer side of the outer edge 92E2 of the hook sheet 92 in the longitudinal direction L. Thus, a force generated when the fastening tape 90 is pulled outward in the width direction W may efficiently affect the waist stretch unit 85, and a fit of the waist stretch unit 85 to the wearer may be improved.

[0094]

Further, in the disposable diaper 10 according to the present embodiment, the pair of leg stretch units 75 is configured to widen outward in the width direction W toward the rear waistline region 30. Thus, it is possible to disperse a force, at which the waist stretch unit 85 is pulled in the longitudinal direction L, outward in the width direction W after the disposable diaper 10 is worn.

[0095]

In general, the body of the wearer is placed so as to cover the entire width of the absorbent core 40a at the time of wearing. Therefore, when the fastening tape 90 is pulled, a portion positioned at an outer side of the body of the wearer in the width direction W, that is, a region at an outer side of the absorbent core 40a in the width direction W is pulled.

[0096]

For example, when a portion at which the fastening tape 90 is pulled is difficult to stretch, the wearing assistant may not determine a degree at which the fastening tape 90 is stretched and may not perform fastening at a proper position.

[0097]

However, since the first region 851 having a relatively high elongation rate is disposed at the outer side of the absorbent core 40a in the width direction W, the wearing assistant fastens the fastening tape 90 by stretching the first region 851. The wearing assistant easily stretches the first region 851, and thus may easily determine a range in which the first region 851 is stretchable. Therefore, the wearing assistant may fasten the fastening tape 90 at a proper position by determining a range in which the fastening tape 90 is stretched.

[0098]

In addition, when the fastening tape 90 is fastened, the first region 851 is disposed at a position corresponding to a hipbone on a side of the wearer. Meanwhile, when the fastening tape 90 is fastened, a body pressure of the wearer is applied to the second region 852 and the third region 853, and the second region 852 and the third region 853 are difficult to stretch and contract.

[0099]

However, for example, in a state in which the wearer is raised after the disposable diaper 10 is mounted on the wearer, a body pressure applied to the rear waistline region 30 of the disposable diaper 10 is reduced. When the body pressure of

Description_UC-1048-PCT 16 the wearer applied to the rear waistline region 30 is reduced, the first region 851, the second region 852, and the third region 853 interlock with each other, and the second region 852 and the third region 853 stretch and contract using the first region 851 as a base point as illustrated in Fig. 4(b).

[0100]

Specifically, the first region 851 is previously extended at the time of attaching the fastening tape 90 when compared to the second region 852 and the third region 853. When each of the second region 852 and the third region 853 extends and contracts in this state, the second region 852 having a relatively low elongation rate is pulled to the first region 851 side using the first region 851 as a base point, the third region 853 having a relatively high elongation rate pulls the second region 852 inward in the width direction W, and the second region 852 extends.

[0101]

In this instance, the first region 851 is positioned near the fastening tape 90, and thus extends when the fastening tape 90 is fastened to the target units 95. In this case, when the third region 853 which is more difficult to extend inward in the width direction W than the second region 852 is present, the second region 852 positioned at a location interposed between the first region 851 and the third region 853 is likely to uniformly extend in the width direction W. As a result, the second region 852 may be uniformly fit to the body while a body of an infant is not tightened with a weak force.

[0102]

When the disposable diaper 10 is fit to the body of the wearer in this way, the disposable diaper 10 is strongly fit to the hipbone on the side of the wearer by the first region 851. In addition, at the dorsal side of the hipbone on the side of the wearer, few hipbones are present, and the body of the wearer is relatively soft. The disposable diaper 10 is weakly fit to a portion in which few hipbones are present by the second region 852. Since the disposable diaper 10 is strongly fit to a region in which the body of the wearer is relatively hard, and the disposable diaper 10 is weakly fit to a region in which the body of the wearer is relatively soft, the disposable diaper 10 may be smoothly fit to the body of the wearer, and a fit around the waist may be enhanced. In other words, antinomy between an original desire of a mother (helper) to avoid tightening an infant with a diaper and the fact that it is preferable to enhance a fit (strength tightening) in order to prevent leakage of excrement without creating a gap between the disposable diaper 10 and the body of the wearer is achieved by a configuration of the invention.

[0103]

The third region 853 is disposed to straddle the center of the disposable diaper 10 in the width direction W. A spine is arranged at a center of the back of the wearer, and the center is dented to the ventral side of right and left regions. Such a dented region (rhombus of Michaelis) corresponds to a depression of a sacrum part, and the third region

Description_UC-1048-PCT 17 853 is disposed in the dented region. In Fig. 4(a), the dented region is indicated by "CR".

[0104]

When the body pressure is reduced after the disposable diaper 10 is worn, the third region 853 contracts while pulling the second region 852. A contracting part may be disposed in a dented part of the wearer. Therefore, it is possible to inhibit a gap from being generated between the center of the back of the wearer and the disposable diaper 10, and to fit the disposable diaper 10 around the entire waist.

[0105]

In addition, since a thickness of the absorbent core 40a at region positioned front side of the rear edge of absorbent core 40a and a thickness of the absorbent core 40a at region positioned rear side of the rear edge of absorbent core 40a are different, a gap is originally easily formed between the body of the wearer and the disposable diaper 10. However, since the rear edge of the waist stretch unit 85 extends beyond the rear edge of the absorbent core 40a to the waist opening side, and the elongation rate of the third region 853 is relatively high, it is possible to more reliably prevent leakage from the dented region at the dorsal side.

[0106]

Since the absorbent core 40a has relatively higher rigidity than other members (the topsheet 50) included in the disposable diaper 10, it is difficult to dispose the absorbent core 40a along the body of the wearer. However, since at least a part of the waist stretch unit 85 overlaps the absorbent core 40a, and the waist stretch unit 85 is disposed at the non-skin contact surface side of the absorbent core 40a, the absorbent core 40a may be fit to the body of the wearer by contraction of the waist stretch unit 85.

[0107]

When the third region 853 is disposed in the entire region of the absorbent core 40a in the width direction W, the width of the absorbent core 40a may be excessively short in the natural state due to contraction of the third region 853. As a result, there is a concern that the width of the disposable diaper 10 may not be ensured at the time of fastening the fastening tape 90, the wearing assistant will have difficulty in grasping the fastening tape 90, and a fitting property will be degraded.

[0108]

However, when the second region 852 is positioned at the inner side of the outside edge of the absorbent core 40a in the width direction W, the second region 852 and the third region 853 are disposed in the entire region of the absorbent core 40a in the width direction W. Therefore, the width of the absorbent core 40a is not extremely short in the natural state, and degradation of the fitting property is suppressed.

[0109]

The inside edge of the first region 851 is located at the inner side of the outside edge of the absorbent core 40a in the width direction W. When the fastening tape 90 is

Description_UC-1048-PCT 18 pulled for the wearing, the wearing assistant extends the first region 851 to fasten the fastening tape 90. In addition, when the first region 851 is stretched to fasten the fastening tape 90, the absorbent core 40a is disposed below the body of the wearer, and the body pressure is applied thereto. Since the inside edge of the first region 851 is disposed at the inner side of the outside edge of the absorbent core 40a in the width direction W, the inside edge of the absorbent core 40a rarely moves below the body of the wearer when the fastening tape 90 is pulled for the wearing. Therefore, when the inside edge of the first region 851 is positioned at an inner side of the outside edge of the absorbent core 40a in the width direction W, the first region 851 is easily stretched using the inside edge of the first region 851 as a base point at the time of pulling the fastening tape 90.

[0110]

An adhesive that bonds the waist stretch unit 85 and the absorbent core 40a together may be disposed such that a plurality of rows is continuous in the longitudinal direction L and the respective rows overlap each other in the width direction W. According to such a configuration, it is possible to continuously bond the waist stretch unit 85 and the absorbent core 40a together in the longitudinal direction L and the width direction W, and to prevent the waist stretch unit 85 from rising from the absorbent core 40a.

[0111]

The elongation rate of the third region 853 in the width direction W may be higher than the elongation rate of the first region 851 in the width direction W. According to such a configuration, when the elongation rate of the third region 853 is higher than the elongation rate of the first region 851, the second region 852 is pulled to the third region 853 side in a state in which the body pressure applied to the rear waistline region 30 is reduced after the fastening tape 90 is fastened. Therefore, a portion contracted by the third region 853 may be gathered in a depression of the dorsal portion of the wearer.

[0112]

The third region 853 overlaps at least a portion of the lower basis weight region 110 in the plan view of the disposable diaper 10. According to such a configuration, the lower basis weight region 110 contracts in the width direction W by the third region 853, and the rear edge of the absorbent core 40a is deformed to the center side in the width direction W. Therefore, a rear edge of the absorbent core 40a may be formed into a cup shape. Buttocks of the wearer may be covered by the cup-shaped absorbent core 40a, and a fitting property around the waist of the wearer may be further enhanced.

[0113]

The rear edge of the absorbent core 40a substantially corresponds to the rear edge of the core wrap 40b, and the waist stretch unit 85 extends to a rear side of the rear

Description_UC-1048-PCT 19 edge of the absorbent core 40a and the rear edge of the core wrap 40b. For example, when the core wrap 40b extends to a rear side of the absorbent core 40a, there is a concern that elasticity of the waist stretch unit 85 may be hindered by the core wrap 40b. However, since the waist stretch unit 85 extends to the rear side of the rear edge of the absorbent core 40a and the rear edge of the core wrap 40b, the core wrap 40b, etc. does not hinder the waist stretch unit 85 from stretching and contracting at region positioned at the rear side of the rear edge of the absorbent core 40a and the rear edge of the core wrap 40b.

[0114]

In addition, the waist stretch unit 85 is not disposed at the rear edge of the disposable diaper 10, and a notch depressed inward in the width direction W and inward in the longitudinal direction L is formed at the side flap 70 at the rear edge of the disposable diaper 10.

[0115]

More specifically, the rear edge of the side flap 70 is depressed inward in the longitudinal direction L in a certain range extending inward in the width direction W from the outside edge of the side flap 70. In other words, the outside edge of the side flap 70 is depressed inward in the width direction W in a certain range extending inward in the longitudinal direction L from the rear edge of the side flap 70.

[0116]

When the rear edge of the disposable diaper 10 is configured in this way, it is possible to inhibit the rear edge of the disposable diaper 10 from turning inside out, and to more reliably cover the waist circumference of the wearer.

[0117]

Even though contents of the invention have been disclosed through the embodiments of the invention as described above, it should not be understood that the description and drawings included in a part of this disclosure limit the invention. From this disclosure, various alternative embodiments, examples and operation technologies will be apparent to those skilled in the art. Therefore, the technical scope of the invention is determined only by matters specifying the invention pertaining to claims valid from the above description.

[0118]

The entire contents of Japanese Patent Applications No. 2015-038605, filed on February 27, 2015 as the basis of the priority claim of this application are hereby incorporated by reference.

[INDUSTRIAL APPLICABILITY] [0119]

According to the invention, it is possible to provide a tape-type disposable diaper capable of enhancing a fit around the waist of the wearer.

Description_UC-1048-PCT 20 [REFERENCE SIGNS LIST] [0120] 10.. . disposable diaper 20.. . front waistline region 25.. . crotch region 30.. . rear waistline region 35.. . leg opening 40.. . absorber 40a... absorbent core 40b... core wrap 50.. . top sheet 60.. . exterior sheet 60a... backsheet 70.. . side flap 75.. . leg stretch unit 80.. . leg side stretch unit 85.. . waist stretch unit 851.. . first region 852.. . second region 853.. . third region 90.. . fastening tape 110.. . lower basis weight region 115.. . first notch 125.. . second notch 200.. . crotch stretch unit L... longitudinal direction W... width direction

Claims

1. A disposable diaper comprising: a front waistline region! a rear waistline region! a crotch region positioned between the front waistline region and the rear waistline region! a longitudinal direction extending from the front waistline region to the rear waistline region! a width direction orthogonal to the longitudinal direction a pair of fastening tapes which extends along the width direction in the rear waistline region and is fastened to the front waistline region! an absorber which straddles the crotch region and extends toward at least one of the front waistline region and the rear waistline region! and a waist stretch unit which is disposed between the pair of fastening tapes and stretches and contracts in the width direction, wherein a center line of the pair of fastening tapes in the longitudinal direction overlaps the waist stretch unit and does not overlap the absorber in a plan view of the disposable diaper, a length of the waist stretch unit in the width direction is longer than a length of the absorber in the width direction, and an elongation rate of a region positioned at an outer side of the absorber in the width direction in the waist stretch unit is different from an elongation rate of a region positioned at an inner side of the absorber in the width direction in the waist stretch unit.

2. The disposable diaper according to claim 1, wherein the elongation rate of the region positioned at the outer side of the absorber in the width direction in the waist stretch unit is larger than the elongation rate of the region positioned at the inner side of the absorber in the width direction in the waist stretch unit.

3. The disposable diaper according to claim 1 or 2, further comprising: a pair of leg openings! and a pair of leg stretch units which is disposed at an inner side of the pair of leg openings in the width direction and stretches and contracts in the longitudinal direction, wherein the waist stretch unit and the pair of leg stretch units do not overlap each other in the plan view of the disposable diaper.

4. The disposable diaper according to claim 3, further comprising: a pair of leg side stretch units extending in the longitudinal direction at an inner side of the pair of leg stretch units in the width direction, wherein the waist stretch unit and the pair of leg side stretch units overlap each other in the plan view of the disposable diaper.

5. The disposable diaper according to any one of claims 1 to 4, wherein the waist stretch unit and the absorber overlap each other in the plan view of the disposable diaper, and a thickness of the absorber in a region overlapping the waist stretch unit is thinner than a thickness of the absorber in another region.

6. The disposable diaper according to any one of claims 1 to 5, further comprising: a side flap extending to an outer side of the absorber in the width direction, wherein each of the pair of fastening tapes includes a base sheet connected to the side flap and a hook sheet which is provided with an engagement hook and fixed to the base sheet, and the absorber is disposed at an inner side of an inner edge of the hook sheet in the longitudinal direction.

7. The disposable diaper according to any one of claims 1 to 6, further comprising: a side flap extending to an outer side of the absorber in the width direction, wherein each of the pair of fastening tapes includes a base sheet connected to the side flap and a hook sheet which is provided with an engagement hook and fixed to the base sheet, an inner edge of the waist stretch unit is disposed at an inner side of an inner edge of the hook sheet in the longitudinal direction, and an outer edge of the waist stretch unit is disposed at an outer side of an outer edge of the hook sheet in the longitudinal direction.

8. The disposable diaper according to claim 3, wherein the pair of leg stretch units is configured to widen outward in the width direction toward the rear waistline region.

9. The disposable diaper according to any one of claims 1 to 8, wherein the waist stretch unit has a first region which extends inward in the width direction from both outside edges of the waist stretch unit, a second region which extends inward in the width direction from an inside edge of the first region and has a lower elongation rate than an elongation rate of the first region, and a third region which extends inward in the width direction from an inside edge of the second region and has a higher elongation rate than the elongation rate of the second region, and at least a part of the first region is positioned at an outer side of the absorber in the width direction.