CN105407847B - Disposable diaper - Google Patents

Abstract

The present invention provides disposable diaper (10), which includes：Absorber (40), with absorbent core；A pair of of magic tape (90)；Waist stretchable sheet has retractility in product width direction；And waistline maintaining part, it is used to disposable diaper being held in the body of wearer.Waist stretchable sheet has the front side waist portion stretchable sheet (86) of the posterior lumbar stretchable sheet (85) for being configured at the rear waist region and the anterior end for being configured at front waist region.A part for posterior lumbar stretchable sheet is configured in a manner of Chong Die with the rear end of absorbent core and is configured in a manner of Chong Die with waistline maintaining part.Front side waist portion stretchable sheet is configured in a manner of adjacent with the anterior end of absorbent core.

Description

disposable diapers

technical field

The present invention relates to a disposable diaper.

Background technique

Conventionally, there is known a disposable diaper which has a front waist region, a rear waist region, and a crotch region, and includes an absorbent body extending across the crotch region and extending to the front waist region and the rear waist region, and a A fastening tape attached to the waist area and the rear waist area (for example, refer to Patent Document 1).

Usually, the fastening tape extends outward in the width direction from an outer end portion in the width direction of the rear waist region of the disposable diaper. When wearing the disposable diaper of Patent Document 1, in the state where the crotch portion of the disposable diaper is arranged on the wearer's crotch, the fastening tape in the rear waist region is pulled to the front waist region and the fastening tape is pulled to the front waist region. Fastened to the front waist area.

Moreover, the elastic member expandable and contractible in the width direction is arrange|positioned at the waist opening part of the disposable diaper of patent document 1. The waist opening of the disposable diaper is closely fitted to the waist of the wearer by expansion and contraction of the elastic member.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2006-20665

However, the above-mentioned disposable diaper has the following problems.

In the disposable diaper of patent document 1, the area|region extended in the width direction from a fastening tape is arrange|positioned separately from an elastic member. The region extending from the fastening tape in the width direction and the region where the elastic member is arranged are arranged so as to be in close contact with the wearer's body. However, the part between the area extending in the width direction of the self-hook and fastening tape and the part between the elastic members is not in close contact with the wearer's body, but protrudes relative to the area extending in the width direction of the self-hook and fastening tape or along with the self-hook and fastening tape. Steps are formed between regions extending in the width direction.

In addition, the absorbent core of the absorbent body is formed of an absorbent material such as pulverized pulp, and the thickness of the region where the absorbent core is arranged is thicker than the thickness of the region where the absorbent core is not arranged. In addition, the thickness of the region where the elastic member is arranged becomes thicker than the state before contraction due to the contraction of the elastic member. Therefore, the thickness of the part located in the waist opening part vicinity of a disposable diaper is thicker than the thickness of a structural member itself.

In the disposable diaper of Patent Document 1, the elastic member is separated from the absorbent core. The thickness of the area|region between an elastic member and an absorptive core is thinner than the thickness of the area|region where an elastic member is arrange|positioned, and is thinner than the thickness of the area|region where an absorptive core is arrange|positioned. Therefore, a step occurs between the region between the elastic member and the absorptive core and the region where the elastic member is arranged, or between the region between the elastic member and the absorptive core and the region where the absorptive core is arranged.

On the other hand, in recent years, the requirements of users (purchasers) of disposable diapers have been increasing, especially when wearing them on infants, they want to reduce the burden on the skin of infants and young children as much as possible. Demands for affordability and appearances that look like underwear are increasing.

However, in such a disposable diaper as described above, since a plurality of steps are formed in the disposable diaper, depending on the user, sometimes the step part may be felt to be irritating to the skin, or the height of the disposable diaper may be affected by the step. Functionality is conspicuous and dissatisfied with the appearance that should be close to underwear.

Contents of the invention

Therefore, this invention was made in view of such a situation, and it aims at providing the disposable diaper which can suppress the dissatisfaction with respect to the burden on skin, and the dissatisfaction of an appearance.

The gist of the disposable diaper (disposable diaper 10) of the present disclosure is that it includes: a front waist region (front waist region 20); a rear waist region (rear waist region 30); a crotch region (inseam region 25), which Located between the front waist region and the rear waist region; product length direction (product length direction L), which is from the front waist region to the rear waist region; product width direction (product width direction W), which Orthogonal to the product length direction; an absorber (absorbent body 40), which spans the crotch region and extends toward at least one of the front waist region and the rear waist region, the absorber has an absorbent Sexual core; a pair of Velcro (Velcro 90), which is configured at the outer end of the product width direction of the rear waist area, for fixing to the front waist area; waist stretch sheet, which spans once the center of the product width direction of the non-toxic diaper, and has stretchability in the product width direction; For holding the disposable diaper on the wearer's body, the waist elastic sheet has a rear waist elastic sheet (rear waist elastic sheet 85) arranged at the rear end of the rear waist region and a rear elastic sheet (85) arranged at the rear waist region. In the front waist elastic sheet (front waist elastic sheet 86 ) at the front end of the front waist region, a part of the rear waist elastic sheet is arranged so as to overlap the rear end of the absorbent core. It is arrange|positioned so that it may overlap with the said waist support part, and the said front side waist elastic sheet is arrange|positioned so that it may adjoin the front side end part of the said absorptive core.

Description of drawings

Fig. 1 is a developed plan view in an extended state of the disposable diaper according to the present embodiment.

Fig. 2 is a plan view in a natural state of a part of the disposable diaper according to this embodiment.

Fig. 3 is a sectional view of the disposable diaper along line F1-F1 shown in Fig. 1 .

Fig. 4 is a sectional view of the disposable diaper along line F2-F2 shown in Fig. 1 .

Detailed ways

Next, embodiment of the disposable diaper 10 of this invention is demonstrated with reference to drawings. In addition, in the description of the drawings below, the same or similar reference signs are attached to the same or similar parts. However, it should be noted that the drawings are schematic, and ratios of dimensions and the like are different from actual ratios of dimensions.

Therefore, specific dimensions and the like should be judged with reference to the following description. In addition, the relationship and the ratio of the mutual dimension may differ between drawings.

(1) Overall structure of disposable diapers

Fig. 1 is a developed plan view of a disposable diaper 10 according to the present embodiment in an extended state. Fig. 2 is a plan view in a natural state of a part (rear end side) of the disposable diaper according to this embodiment. Fig. 3 is a sectional view of the disposable diaper along line F1-F1 shown in Fig. 1 . Fig. 4 is a sectional view of the disposable diaper along line F2-F2 shown in Fig. 1 .

The stretched state shown in FIG. 1 is a state in which the elastic member 81 of the leg elastic portion 75 and the leg side gathers 80 is stretched until the front sheet 50, the side flap 70, etc. constituting the disposable diaper are not wrinkled. On the other hand, the natural state is when the disposable diaper 10 is enclosed in a package, etc., and the disposable diaper 10 is taken out from the package, and in this state, it is kept in an environment of 20°C ± 2°C and a relative humidity of 60% ± 5% RH. The state after 12 hours of storage. In the disposable diaper in a natural state, gathers are formed in the surface sheet 50, the side panel 70, etc. which comprise a disposable diaper.

The disposable diaper 10 is a belt type disposable diaper. Belt-type diapers refer to those in which the outer end in the product width direction of the front waist region and the outer end in the product width direction of the rear waist region are not joined before use, but are joined by a fastening member such as a hook and loop during use. diaper.

The disposable diaper 10 has a front waist region 20 , a crotch region 25 and a rear waist region 30 . The front waist region 20 is a portion in contact with the wearer's front waist (abdomen). In addition, the rear waistline region 30 is a part which contacts the back waistline part (back part) of a wearer. The crotch region 25 is located between the front waist region 20 and the rear waist region 30 .

In addition, in the present embodiment, the direction from the front waist region 20 to the rear waist region 30 is referred to as the product longitudinal direction L, and the direction perpendicular to the product longitudinal direction L is referred to as the product width direction W.

The disposable diaper 10 includes an absorbent body 40 that spans the crotch region 25 and extends from the crotch region 25 toward at least one of the front waist region 20 and the rear waist region 30 . The absorbent body 40 includes an absorbent core 40a and a core cover 40b.

The absorptive core 40a is similar to the absorptive core of the conventional disposable diaper, and can be comprised suitably using well-known members and materials, such as ground pulp and a superabsorbent polymer. The absorptive core 40a is covered with the sheet-shaped core cover 40b. The exterior sheet is arrange|positioned on the non-skin contact surface side surface of a disposable diaper. The exterior sheet is formed of, for example, a nonwoven fabric.

The core cover 40b is a sheet covering the absorbent core 40a. At least a part of the skin surface side of the core cover layer 40b is formed of various liquid-permeable fiber nonwoven fabrics or tissue paper sheets. For example, air-through fiber nonwoven fabrics, spunbonded nonwoven fabrics, SMS (spunbond-meltblown-spunbond) nonwoven fabrics with a grammage of about 10g/m ² to 30g/ ^m2 can be used, or about 10g/ ^m2 - 30 ^g /m2 sheet of tissue paper.

A low-rigidity portion 110, which is a low-rigidity region, is provided at a portion of the absorbent body 40 located in the rear waist region, and the weight per unit area of the low-rigidity portion 110 is lower than that of other parts of the absorbent body, or Absorbent core 40a is absent. The low rigidity portion 110 has a shape in which the length in the product width direction gradually becomes shorter from the center in the product width direction of the end portion of the absorbent body 40 on the rear waist region side toward the front waist region side. More specifically, the low-rigidity part 110 is wedge-shaped when the disposable diaper 10 is planarly viewed. In addition, the boundary between the absorptive core 40a and the low-rigidity part 110 is formed by the circular arc convex toward the center in the product width direction W. The part of the absorber 40 outside the low rigidity part 110 in the product width direction has a trapezoidal shape protruding toward the end part on the rear waistline region side.

Moreover, the thickness of the edge part of the product longitudinal direction of an absorptive core is thinner than the thickness of the center of the product longitudinal direction of an absorptive core. More preferably, the portion of the absorbent core that overlaps the rear waist elastic sheet is thinner than the thickness of the absorbent core that does not overlap the rear waist elastic sheet at an end in the product length direction of the absorbent core.

Adjustment of the thickness can be realized by embossing for reducing the basis weight of the absorbent core. In addition, when measuring the thickness, it can be measured using a PEACOCK dial thickness gauge manufactured by Ozaki Seisakusho. After adjusting so that the measuring terminal becomes circular with a diameter of 10 mm to a load of 6.0 gf/cm ² , the measurement site is measured. When measuring the thickness, it is measured in the stretched state of the disposable diaper.

A liquid-permeable topsheet 50 is provided on the surface side (skin contact surface side) of the absorber 40 . Moreover, the liquid-impermeable back sheet 60a is provided in the back side (non-skin contact surface side) of the absorber 40. As shown in FIG. The exterior sheet 60 is provided on the back side (non-skin contact surface side) of the back sheet 60a.

The back surface sheet 60a is arrange|positioned in the product longitudinal direction inside rather than the front side end part 10F of a disposable diaper, and is arrange|positioned in the product longitudinal direction inside rather than the rear side edge part 10R of a disposable diaper. The back sheet 60a is arrange|positioned at the inside of the product width direction rather than the product width direction edge part of a disposable diaper.

Side flaps 70 are respectively provided on side edge portions in the product width direction W of the absorber 40 . The side panels 70 straddle the front waist region 20 , the crotch region 25 , and the rear waist region 30 , and are arranged on the outside of the absorber 40 in the product width direction. The side flaps 70 are formed of one or two or more laminated nonwoven fabrics.

A pair of leg openings 35 are formed in the side flaps 70 of the disposable diaper 10 . The leg openings 35 are respectively provided at side ends in the product width direction of the disposable diaper, and are portions arranged along the wearer's leg circumference when the disposable diaper is worn by the wearer. The leg openings 35 are recessed toward the center of the absorbent main body in the product width direction.

In addition, the hook and loop fasteners 90 are respectively provided on the pair of side flaps 70 . The hook and loop fastener 90 is arranged at the outer end in the product width direction of the rear waist region, and is used for fastening to the front waist region. The fastening tape 90 extends to a position outside the side flap 70 in the product width direction. The fastening tape 90 extends along the product width direction W in the rear waist region 30 and is fixed to the non-skin-contacting surface of the front waist region 20 to hold the disposable diaper 10 on the wearer's body.

The target portion 95 is arranged on a non-skin-contacting surface in the front waist region, and is configured so that the pair of fastening tapes 90 can be respectively fixed.

As a top sheet and an exterior sheet, the nonwoven fabric sheet which has a high basis weight part and a low basis weight part alternately in the product width direction can be used. By using such a top sheet, the force is concentrated on the boundary between the high basis weight part and the low basis weight part, and the extensibility part is easily extended, and elongation can be expressed. As a modified example, a nonwoven fabric sheet having high-density portions and low-density portions alternately at least in the product width direction may be used for the top sheet and the exterior sheet. In the nonwoven fabric sheet having high-density portions and low-density portions alternately, the high-density portions are formed in a continuous line or in a state of dots arranged at intervals.

The nonwoven fabric sheet constituting the front sheet or the exterior sheet is formed of a sheet having no heat-seal points formed by point embossing or line embossing or a sheet having an area ratio of 5% to 15% of point embossing and line embossing . The area ratio of embossing is the ratio of the area where embossing is formed. For example, it is the area of the part in which the embossing was formed of the exterior sheet with respect to the whole area of an exterior sheet.

In the present embodiment, the waist holding portion is constituted by the front waist region 20 , the rear waist region 30 , and the hook and loop fastener 90 . The waist holding portion of the rear waist region 30 is located in a range extending in the product width direction from the region where the fastening portion of the surface fastener 90 is provided. The waistline holding portion of the front waistline region 20 is located in a range extending from the region where the target portion 95 is provided in the product width direction.

The side flaps 70 are provided with a pair of leg expansion and contraction parts 75, which are arranged on the inner side of the product width direction than the leg openings 35 and on the outer side of the product width direction than the absorbent body 40, and can be extended along the product length. The direction L stretches.

The leg stretchable portion 75 only needs to be configured so that the leg opening 35 can expand and contract in the product longitudinal direction, and may be arranged along the leg opening 35 or may be arranged in a state inclined relative to the leg opening 35 .

In addition, a pair of auxiliary elastic parts 77 are arranged on the outside of the leg elastic part 75 in the product width direction. . By shrinking the region of the side flap 70 where the auxiliary stretchable portion 77 is provided, the side flap 70 can be made to follow the swollen buttocks of the wearer, so that the region can be used to cover the buttocks.

In addition, the leg expansion part 75 and the auxiliary expansion part 77 are parts that are substantially contracted in the product longitudinal direction by elastic members such as rubber bands, and are concepts other than parts where elastic members are arranged without exerting contraction force.

The leg expansion-contraction part 75 is formed by the elastic member provided three on each side which expands and contracts along the product length direction. The auxiliary expansion-contraction part 77 is formed by the elastic member which expands and contracts along the product longitudinal direction, and is provided on each side. The elastic member of the present embodiment includes polyurethane elastic fibers and natural rubber.

The rear side end part 75R of the leg expansion-contraction part 75 is arrange|positioned at the front side rather than the surface fastener 90, and the position inside the product width direction rather than the surface fastener. Therefore, the region on the front side and on the inner side in the width direction than the surface fastener 90 is contracted by the leg stretchable portion 75 .

The front end portion 77F of the auxiliary telescopic portion 77 is disposed on the rear side of the front end portion 75F of the leg telescopic portion 75 . Therefore, the region behind the front end 75F of the leg expansion-contraction unit 75 is contracted by the auxiliary expansion-contraction unit 77 . The rear end portion 77R of the auxiliary telescopic portion 77 is disposed on the rear side of the rear end portion of the leg telescopic portion. Therefore, the region behind the leg expansion-contraction unit 75 is contracted by the auxiliary expansion-contraction unit 77 .

The crotch region of the disposable diaper can be lifted toward the wearer's crotch by the leg stretchable portion 75 . In addition, the force of lifting the crotch region by the leg stretchable portion can be transmitted to the hook and loop fastener 90 by the auxiliary stretchable portion 77 . Therefore, in the state where the fastening tape 90 is fixed, it is not only easy to use the fastening tape 90 to make the area to be held on the wearer's waistline and the area where the leg expansion and contraction parts 75 are arranged close to the wearer, but also easy to The region between the fastening tape 90 and the leg stretchable portion 75 is made to closely adhere to the wearer.

In addition, the region on the outer side in the product width direction than the leg stretchable portion can be contracted by the auxiliary stretchable portion, so that the buttocks can be appropriately covered by the rear waist region of the side flap. Therefore, in particular, the rear leg openings can be suppressed from being raised when worn. In addition, the leg openings can be drawn closer to the body by contraction of the leg expansion-contraction parts, thereby suppressing deviation of the leg openings.

The stretchable leg portion 75 is disposed between the side flap 70 and the outer sealing sheet 60 . Alternatively, in a region where the back sheet 60a arranged between the absorber 40 and the outer sheet 60 is provided, the leg stretchable portion 75 is arranged between the back sheet 60a and the side flaps 70 .

The elongation ratio of the leg stretchable portion 75 is preferably 1.7 times to 2.4 times. In this embodiment, the elongation ratio of the leg expansion-contraction part 75 is set to 1.9 times - 2.2 times. In addition, the elongation rate refers to the degree of elongation of the leg expansion-contraction part, and is defined as follows.

The elongation rate of the leg stretching part = (the length of the stretched state of the leg stretching part) ÷ (the length of the natural state of the leg stretching part)

In addition, it is preferable that the elongation rate of the auxiliary expansion-contraction part 77 is 1.6 times - 2.4 times. In addition, the elongation rate of the auxiliary expansion-contraction part 77 means the degree of expansion of an auxiliary expansion-contraction part, and is prescribed|regulated as follows.

Elongation rate of auxiliary telescopic part = (length of auxiliary telescopic part in extended state) ÷ (length of auxiliary telescopic part in natural state)

In addition, in this specification, this elongation rate is measured as follows, for example.

First, when the disposable diaper 10 is enclosed in a package or the like, the disposable diaper 10 is taken out from the package. Next, cut out the arrangement area of the measurement object such as the leg expansion part. At this time, cutting is also performed including the exterior sheet joined to the measurement target such as the leg stretchable portion. Measure the elongation of the cut sample, thereby measuring the elongation of the measurement object.

Each sample was placed in an environment of 20°C±2°C and a relative humidity of 60%±5%RH for 60 minutes, and the length of the measurement object was measured along the stretching direction. Let this length be "the length in the natural state of a measurement object (leg expansion-contraction part etc.)."

Next, the length of the desired region in the stretching direction in this state (that is, the natural state) and when the sample is stretched from the natural state to a state where no wrinkles due to the elastic member can be visually observed on the non-stretchable sheet are measured. The length of the expected region in the stretching direction. Let this length be "the length in the extended state of the measuring object (leg expansion-contraction part etc.)".

Elongation was measured by using these measurements and performing calculations using the formula.

In addition, the "length" in this specification is measured by the following measurement method.

A sample obtained by taking out the disposable diaper 10 from the package with the disposable diaper 10 enclosed in a package, etc., was used in this state at 20° C. ± 2° C. and a relative humidity of 60% ± 5% RH. A sample obtained by standing in an environment for 12 hours.

Next, by using an elastic measuring tape manufactured by Nippon Affinity Measurement Co., Ltd. (tape part: glass fiber as a base material, polyvinyl chloride as a cover layer), the measurement target site is measured in such a way that it follows the measurement target site. The length in this state is measured. In addition, the length of the stretched state was measured when the disposable diaper 10 was stretched from the natural state to the state in which wrinkles due to the elastic member could not be visually observed.

Here, the measurement is performed for 10 samples in each state, and the average value thereof is defined as the length.

In addition, a pair of leg side gathers 80 extending along the product length direction L is provided inside the pair of leg stretch parts 75 (near the center side in the product width direction W). The leg side gathers 80 are provided at inner end portions of the side panels 70 in the product width direction, and are stand-up stretch gathers arranged on the inside of the leg stretch portion 75 in the product width direction. The leg side gathers 80 are arranged on the inner side in the product width direction than the leg stretch parts 75 . The leg side gathers 80 may employ a conventionally known structure, and specifically, may be formed of a sheet separate from the side flaps 70 .

The disposable diaper 10 has a waist elastic sheet which straddles the product width direction center of a disposable diaper and has elasticity in the product width direction. The waist elastic sheet has the rear side waist elastic sheet 85 arrange|positioned at the rear side edge part of a disposable diaper, and the front side waist elastic sheet 86 arrange|positioned at the front side edge part of a disposable diaper. Moreover, in FIG. 1, the imaginary line L1 which passes the product width direction center of a disposable diaper and extends along a product longitudinal direction is shown.

The rear end portion 10R of the disposable diaper has a curved shape in which the center of the rear end portion 10R in the product width direction is recessed inward in the product length direction from the product width direction outer side of the rear end portion 10R in the natural state of the disposable diaper. . The rear end of the rear waist elastic sheet 85 located at the rear end of the disposable diaper also has a curved shape in which the center in the product width direction is concave toward the product length direction inner side than the product width direction outer side in a natural state.

In addition, in the stretched state (state shown in FIG. 1 ) in which the disposable diaper has been stretched, the front side end portion 85F of the rear side waist elastic sheet 85 has a product width direction center of the front side end portion 85F that is larger than the front side. The outer side in the product width direction of the end portion 85F is a curved shape dented toward the outer side in the product longitudinal direction. In addition, the curved shape of a rear side waist elastic sheet is not formed in the whole area|region of the front side end part 85F, but is formed in the center of the width direction which is a part of the front side end part.

The rear waist stretch sheet 85 is disposed between a pair of hook and loop fasteners in the product width direction. A part of the front side edge part 85F of the back side waist elastic sheet 85 overlaps with the absorptive core 40a. The rear side end part 85R of the back side waist elastic sheet 85 is aligned with the rear side end part of the disposable diaper. The length of the product width direction of the back side waist elastic sheet 85 is longer than the length of the product width direction of the absorptive core 40a, and is longer than the length of the width direction of the back sheet 60a. The rear side waist elastic sheet extends to the outer side of the product width direction than the absorptive core 40a, and extends to the outer side of the product width direction than the backsheet 60a. A part of the rear side waist elastic sheet 85 is arranged so as to overlap the waist holding part.

The front end portion 10F of the disposable diaper has a curved shape in which the center of the front end portion 10F in the product width direction is recessed from the product width direction outer side of the front side end portion 10F to the product length direction inner side in the natural state of the disposable diaper. . The front side end portion 86F of the front side waist elastic sheet 86 located at the front side end portion of the disposable diaper also has a product width direction center of the front side end portion 86F in a natural state, which is outward in the product width direction of the front side end portion 86F. A curved shape in which the inner side of the product in the longitudinal direction is depressed.

In addition, in the stretched state (state shown in FIG. 1 ) in which the disposable diaper has been stretched, the rear side end portion 86R of the front side waist elastic sheet 86 has a product width direction center ratio of the rear side end portion 86R to the rear side. The outer side in the product width direction of the end portion 86R is a curved shape dented toward the outer side in the product longitudinal direction. In addition, the curved shape of the front side waist elastic sheet is not formed in the whole area|region of 86 R of rear side end parts, but is formed in the center of the width direction which is a part of 86 R of rear side end parts.

The front waist elastic sheet 86 is adjacent to the absorbent core 40a and the target portion 95 in the product length direction. More specifically, 86 R of rear side end parts of the front side waist elastic sheet 86 are adjacent to the front side end part of the absorptive core 40a, and are adjacent to the front side end part of the target part 95. As shown in FIG. 86 R of rear side edge parts of the front side waist elastic sheet 86 are located in the outer side than the absorptive core 40a and the target part 95 in the product longitudinal direction. In addition, the state where the front side waist elastic sheet 86 and the absorptive core 40a are adjacent, and the state where the front side waist elastic sheet 86 is adjacent to the target part 95 mean the state where the distance between them is 0 mm - 5 mm.

The front side end part 86F of the front side waist elastic sheet 86 is aligned with the front side end part of the disposable diaper. The length of the product width direction of the front side waist elastic sheet 86 is longer than the length of the product width direction of the absorptive core 40a, and is longer than the length of the width direction of the back sheet 60a. The front side waist elastic sheet 86 extends to the outer side of the product width direction than the absorptive core 40a, and extends to the outer side of the product width direction than the backsheet 60a.

86 R of rear side end parts of the front side waist elastic sheet 86 are adjacent to the absorptive core 40a and the target part 95 in the product longitudinal direction. 86 R of rear side edge parts of the front side waist elastic sheet 86 are located in the outer side than the absorptive core 40a and the target part 95 in the product longitudinal direction.

The front end 60aF of the back sheet 60a is located between the front end 10F of the disposable diaper and the front end of the absorbent core 40a, and the rear end 60aR of the back sheet 60a is located at the rear end of the disposable diaper. Between 10R and the rear end of the absorptive core 40a.

In this embodiment, as the waist stretch sheet, it is preferable to use a sheet whose width in a second direction perpendicular to the stretching direction becomes narrow (so-called narrowing) when stretched in one direction of the sheet. .

As the waist elastic sheet, a sheet made of a mixture of elastic and extensible elastic fibers and non-elastic but extensible non-elastic fibers can be used, especially a sheet with a grammage of 20 g/ m ² to 80 g/m ² , more preferably 40 g/m ² to 75 g/m ² , still more preferably 50 g/m ² to 70 g/m ² spunbonded nonwoven fabric sheet, in which the spunbonded nonwoven fabric sheet , the elastic fiber is a long filament of polyurethane fiber with a fineness of 2dtex to 6dtex, and the non-elastic fiber is at least one of the long filaments of polyolefin fibers, polyester fibers and polyamide fibers with a fineness of 2dtex to 6dtex In the filament, the elastic fiber and the non-elastic fiber are blended at a weight mixing ratio of the elastic fiber to the non-elastic fiber in the range of 40:60 to 60:40. A part of the non-elastic fiber layer of the non-woven fabric, which is a mixture of inelastic fibers and elastic fibers, is broken by a gear, so that the non-woven fabric exhibits stretchability. If it is a sheet|seat which can be narrowed as another waist elastic sheet, it can become the narrowed shape in this structure relatively easily. In addition, the elastic waist sheet is not limited to a nonwoven fabric sheet, and may be formed of a film sheet. In addition, an elastic sheet is prepared in advance, and the elastic sheet is pre-deformed so that the width in the longitudinal direction of the product is changed (cut so as to protrude inward). The waist elastic sheet is bonded to the exterior sheet 60 by hot-melt adhesive or heat treatment.

It is preferable that the elongation rate of the back side waist elastic sheet 85 is 1.4 times - 1.8 times. In the present embodiment, the elongation ratio of the rear waist elastic sheet 85 is set to 1.5 times to 1.6 times. In addition, the elongation rate means the degree of elongation of the rear side waist elastic sheet, and is defined as follows.

Elongation rate of the rear waist elastic sheet = (length of the rear waist elastic sheet in an extended state) ÷ (length of the rear waist elastic sheet in a natural state)

The elongation rate of the front side waist elastic sheet 86 is preferably 1.3 times to 1.7 times. In this embodiment, the elongation rate of the front side waist elastic sheet 86 is set to 1.4 times - 1.6 times. In addition, the elongation rate means the degree of elongation of the front side waist elastic sheet, and is defined as follows.

The elongation rate of the front waist elastic sheet = (the length of the front waist elastic sheet in the stretched state) ÷ (the length of the front waist elastic sheet in the natural state)

By providing such a sheet-shaped waist elastic sheet, the area where the waist elastic sheet is disposed (the vicinity of the waist opening) is arranged along the body in a plane. Therefore, the wearer's body can be well covered. On the other hand, in a structure in which a plurality of linear elastic members are provided, the linear elastic members partially follow the body, but strictly speaking, the portions between the linear elastic members do not contact the body. Therefore, the linear elastic member portion tends to be shifted along the body along the thread, thereby failing to sufficiently cover the wearer's body. In addition, since the waist elastic sheet itself has elasticity, the waist elastic sheet is also excellent in flexibility and can provide a feeling of cushioning around the waist. In addition, in a state where the waist elastic sheet is shrunk, the portion where the waist elastic sheet is disposed tends to be in a bulky state, and thus is in a state excellent in texture.

In the present embodiment, the waist elastic sheet is joined to a sheet arranged to sandwich the waist elastic sheet. Specifically, the waist elastic sheet is arranged between the exterior sheet 60 and the back sheet 60a. However, in the structure in which the core wrap 40b extends to a position outside the absorbent core 40a in the product longitudinal direction, the waist stretch sheet may be arranged between the core wrap 40b and the back sheet 60a or between the core wrap 40b and the exterior sheet 60. between. The position of the waist expansion piece is not particularly limited. Moreover, the waist elastic sheet may be arrange|positioned between the side panel 70 and the back sheet 60a or between the side panel 70 and the exterior sheet 60 in the area|region where an absorber is not arrange|positioned. The waist elastic sheet is bonded to the exterior sheet 60 and the like by hot-melt adhesive or heat treatment.

In the region where the waist elastic sheet is arranged, the joints between the sheets (specifically, the front sheet, the back sheet, and the waist elastic sheet) are fixed by intermittently applied adhesives (hot-melt adhesives). Intermittent coating is not a state of planar coating, but a state of coating while drawing an S shape, a spiral shape, etc. with a linear adhesive.

The rear waist elastic sheet 85 is arranged so as to overlap with a part of the low rigidity part 110 of the absorber when the disposable diaper is planarly developed. In addition, in this embodiment, the rear waist elastic panel 85 is arranged so as to overlap a part of the low rigidity part 110 , but the entire rear side waist elastic panel 85 may be arranged so as to overlap the low rigidity part 110 .

By forming such a low rigidity portion 110, the expansion and contraction of the rear waist elastic sheet 85 is not hindered. Since the space between the absorbers is narrowed, the absorber 40 is also less likely to bulge in an unexpected shape. The part where the low rigidity part 110 is formed is hard to rise, and this low rigidity part 110 which is difficult to rise is formed in the product width direction center of a disposable diaper. Therefore, it can suppress that a step|step difference generate|occur|produces in the product width direction of a disposable diaper between an absorptive core and a waist elastic sheet. In addition, not only the low-rigidity portion may be formed in the rear end portion of the absorber but also the low-rigidity portion may be formed in the front end portion of the absorber.

In addition, the waist elastic sheet of this embodiment is configured to expand and contract in the product width direction, but the waist elastic sheet may be configured to expand and contract in the product width direction and the product longitudinal direction.

The hook and loop fastener 90 is attached to a region of the side flap 70 corresponding to the rear waist region 30 . The fastening tape 90 includes: a substrate sheet 91, which is connected to the side wings 70; and a hook sheet 92, which is fixed to the substrate sheet 91, and is provided with a plurality of engaging hooks (not shown) as engaging members at the hook sheet 92. icon). The hook piece 92 is a region provided with an engaging member, and the waistline holding part in the rear waistline region is a region extending from the hook piece 92 in the product width direction.

The hook piece 92 is fixed to the base material sheet 91 , specifically, the hook piece 92 is joined to the base material piece 91 . The joining between the hook piece 92 and the base material piece 91 is preferably performed so that the rigidity of the surface fastener 90 is not increased more than necessary. Specifically, it is preferable that the hook piece 92 and the base material piece 91 are bonded by intermittently applied hot-melt adhesives such as dots, lines, or spirals. In addition, the hook piece 92 and the base material sheet 91 may be bonded by heat sealing or the like.

The base sheet 91 is formed of a nonwoven fabric in which one sheet or two or more sheets are stacked. As the base sheet 91 , a nonwoven fabric produced by a production method such as spunbond (SB) or spunbond-meltblown-spunbond (SMS) can be used. The basis weight of the nonwoven fabric constituting the base material sheet 91 (total basis weight in case of a plurality of sheets) is 30 g/m ² to 120 g/m ² , preferably 40 g/m ² to 90 g/m ² .

The fastening tape includes: a base portion 93 that overlaps the exterior sheet; and an overhang portion 94 that extends to a position outside the exterior sheet in the product width direction. The base portion 93 is a portion of the base material sheet 91 that overlaps with the exterior sheet in the state where the fastening tape is unfolded. The protruding portion 94 is a portion of the base material sheet 91 that does not overlap with the exterior sheet. In the stretched state of the disposable diaper shown in FIG. 1 , in the product length direction, the product length direction center of the protruding portion is aligned with the product length direction center of the base portion. However, in the natural state of the disposable diaper, along with the bending of the rear side waist elastic sheet 85, the position of the hook and loop fastener will change, so that the center of the product length direction of the protruding portion is located closer to the center of the product length direction of the base portion. The position outside the length of the product.

In addition, in the present invention, the state in which members overlap is a concept that includes not only a state in which members overlap directly but also a state in which members overlap indirectly (a state in which other members are sandwiched).

The target portion 95 is provided on the non-skin contact side of the exterior sheet 60 in the front waist region. The target portion 95 is configured to be hooked by an engaging hook of the surface fastener, and functions as a loop in a locking system including a hook and a loop. For the target portion, for example, an air-through nonwoven fabric can be used.

For the target portion 95 , for example, a fibrous nonwoven fabric made of polyolefin-based thermoplastic synthetic resin fibers or a polyolefin-based thermoplastic synthetic resin film can be used. In addition, the ring attached to the target portion can be formed of polyolefin-based thermoplastic synthetic resin.

In addition, as the target part 95, the fluffy nonwoven fabric which prevents the surface of a nonwoven fabric from fluffing can also be used by embossing a part of a nonwoven fabric which is fluffy.

In addition, it is also possible to form the exterior sheet 60 of the disposable diaper from a non-woven fabric, and to print the pattern representing the installation position of the hook and loop fastener 90 on the back sheet 60a or the side of the exterior sheet 60 that is not in contact with the skin, or to The sheet|seat of a pattern is arrange|positioned on the back sheet 60a or the non-skin contact side of the exterior sheet 60, and serves as a target part.

When wearing the disposable diaper, the wearer pulls the fastening tape in the rear waist area to the front waist area. The wearer fixes the fastening tape to the target portion while pulling the fastening tape close to the front waist region.

(2) Manufacturing method of disposable diapers

Next, an example of the manufacturing method of the disposable diaper of this embodiment is demonstrated. In addition, existing methods can be used for methods not described in this embodiment. In addition, the manufacturing method demonstrated below is an example, and it can also manufacture by another manufacturing method. The manufacturing method of a disposable diaper includes at least a component forming process, a component mounting process, a leg circumference forming process, and a cutting process.

In the manufacturing method of disposable diapers, the continuum of the state in which the disposable diaper is continuous in the product length direction is manufactured, and the continuum is cut into the size of one product along the product width direction W, thereby manufacturing individual disposable diapers. diaper.

In the component forming step, the components constituting the disposable diaper are formed. Specifically, for example, the absorbent core 40a is formed by laminating absorbent materials.

In the component placement process, other fabrics, absorbers, leg stretchable parts 75, auxiliary stretchable parts, etc., are placed on the continuous fabrics constituting the back sheet and the continuous fabrics constituting the waist stretch sheet and the front sheet. The part 77 etc. comprise the component parts of the disposable diaper 10. As shown in FIG.

At this time, the waist elastic sheet is in a state in which the front waist elastic sheet 86 of an arbitrary disposable diaper and the rear waist elastic sheet 85 of a disposable diaper adjacent to the arbitrary disposable diaper are integrated. Utilize suction member etc. to hold the both ends of this elastic sheet (in the state that becomes disposable diaper and become the part of product width direction outside end), make elastic sheet stretch along the product width direction of disposable diaper and The elastic sheet is pasted on the continuous woven sheet. Since the stretchable sheet is stretched in a state where both ends of the stretchable sheet are held, the both ends of the stretchable sheet are basically not stretched. The elongation rate in the product width direction of the both ends of an elastic sheet is lower than the elongation rate in the product width direction of the area|region located between the said both ends of an elastic sheet.

Specifically, in the area where the waist elastic sheet is arranged in the disposable diaper, three divisions with different elongation ratios are formed. The center of the product width direction of the area where the waist elastic sheet is arranged is defined as the central area, and the product width direction ends (corresponding to both ends of the waist elastic sheet) of the area where the waist elastic sheet is arranged are referred to as side regions, When the region between the central region and the side regions is defined as the middle region, the relationship of elongation satisfies: elongation in the product width direction of the central region > elongation in the product width direction of the middle region > side portions The elongation in the product width direction of the area.

The elongation in the product width direction of the central region can be set to 1.4 times to 1.8 times. The elongation in the product width direction of the side region is set lower than the elongation in the product width direction of the center region, and can be set to 1.0 to 1.1 times. The elongation in the product width direction of the middle region is set to be lower than the elongation in the product width direction of the central region and higher than that of the side regions, and can be set to 1.2 to 1.3 times. In addition, the elongation ratio in the product width direction of the side region may be 1.0 times, and the side region may be a substantially non-elongated region.

In addition, the stretchable sheet stretched in the product width direction shrinks in the product length direction. In particular, the elastic sheet is narrowed at the center in the product width direction. Therefore, the length in the product longitudinal direction at the center in the product width direction of the stretchable sheet in the stretched state is shorter than the length in the product longitudinal direction at the ends in the product width direction. The stretchable sheet pasted in such a narrowed state becomes, as shown in FIG. 1 , the rear end of the front waist stretchable sheet and the rear waist stretchable, which correspond to the ends of the stretchable sheet in the product length direction. A curved shape in which the center of the width direction of both the front end portions of the sheet is recessed from the width direction outer side.

In the leg circumference forming step, the front sheet 50, the exterior sheet 60, and the back sheet 60a are cut. Thereby, the front side end part 77F of the auxiliary expansion-contraction part 77 is cut|disconnected, and the leg opening part 35 arrange|positioned at the wearer's leg circumference is formed.

In the cutting process, the continuous body on which the top sheet 50, the back sheet 60a, the absorber 40, etc. are arranged is cut along the product width direction W into the size of one product. Thereby, the disposable diaper 10 is manufactured.

The continuous body is cut out for each product, and the stretched state of the waist stretch sheet and the leg stretch portion provided in the disposable diaper is released and becomes a natural state. After the stretched state is released, the waist elastic sheet in the state of shrinking during stretching is deformed so as to return to the state before shrinking. Therefore, the rear end of the rear waist elastic sheet and the front end of the front waist elastic sheet are linear in an extended state, but are deformed into a curved state in a natural state.

In addition, when the continuum is cut for each product to be in a natural state, the front end of the front waist elastic sheet shrinks compared to the rear end of the front waist elastic sheet, and the rear waist elastic sheet shrinks. The rear end of the rear waist stretch sheet shrinks compared to the front end of the waist. The front end of the front waist elastic sheet is farther away from the absorbent core 40a than the rear end of the front waist elastic sheet, so that the front end of the front waist elastic sheet is not affected by the rigidity of the absorbent core 40a and is more shrink. The rear side end of the rear waist elastic sheet is farther away from the absorbent core 40a than the front end of the rear waist elastic sheet, so that the rear end of the rear waist elastic sheet is not affected by the rigidity of the absorbent core 40a and is more shrink.

Compared with the rear end of the front waist elastic sheet, the front end of the front waist elastic sheet shrinks, so that the front end of the disposable diaper becomes the center of the product width direction than the front end of the disposable diaper. It is a curved shape in which the outer side of the product width direction is concave toward the inner side of the product length direction. Similarly, compared with the front end of the rear waist elastic sheet, the rear end of the rear waist elastic sheet shrinks, so that the rear end of the disposable diaper becomes the center of the product width direction than the rear of the disposable diaper. A curved shape in which the outer side in the product width direction of the side end is depressed toward the inner side in the product length direction.

(3) Function and effect

The rear waist elastic sheet 85 and the rear edge part of the absorptive core 40a overlap, and the rear waist elastic sheet 85 and the absorptive core 40a are not separated. For example, the area|region between a waist elastic sheet and the absorptive core 40a protrudes, and the level|step difference by thickness change may stand out by this area|region. However, since a part of the rear side waist elastic sheet 85 overlaps with the rear side edge part of the absorptive core 40a, thickness can be changed gradually by this overlapping part.

In addition, a part of the rear side waist elastic sheet 85 overlaps with the waist holding part. Therefore, it is possible to suppress the region between the waistline holding part and the waist elastic sheet from protruding, or the region to have a step with respect to the waistline holding part or the like.

By making the step gradually become smaller toward the rear end of the disposable diaper, it is possible to suppress the uncomfortable feeling on the skin due to the step. Moreover, since the thickness of a disposable diaper changes smoothly, the appearance like underwear can be realizable. Such a disposable diaper can suppress dissatisfaction with respect to the burden on the user's skin and dissatisfaction with respect to appearance.

In addition, in the disposable diaper according to the present embodiment, the thickness (natural state) of the portion where the waist elastic sheet is disposed is about 1.5 mm to 3.0 mm, and the thickness of the portion where the absorbent core is disposed is about 3.5 mm to 4.5 mm. The thickness of the product longitudinal direction end part (the part where a back sheet is not arrange|positioned) of a diaper is about 1.0 mm - 2.0 mm.

The front waist elastic sheet 86 is arranged adjacent to the front end of the absorbent core 40a, and the area thickened by the front waist elastic sheet is adjacent to the area thickened by the absorbent core 40a. Therefore, also in the front waist region, the thickness of the disposable diaper can be smoothly changed to realize an appearance like underwear.

The front end portion 60aF of the back sheet is located between the front end portion 10F of the disposable diaper and the front end portion of the absorbent core 40a, and the rear end portion 60aR of the back sheet is located between the rear end portion of the disposable diaper and the absorbent core. between the rear ends of the core 40a. Thickness can be changed more smoothly by providing the area|region between the absorptive core 40a and the end part of the product longitudinal direction of a disposable diaper by providing the thickness change by presence or absence of a backsheet.

The rear end 86R of the front waist elastic sheet 86 is arranged adjacent to the front end of the target portion, and the front waist elastic sheet 86 that does not overlap the target portion shrinks in the natural state of the disposable diaper. On the other hand, the target portion 95 is a site necessary for fixing the surface fastener, and when this site shrinks, wrinkles are generated, and the engagement (joining) of the surface fastener becomes insufficient. In addition, generally, compared with other sheets (front sheet, back sheet, etc.) of a disposable diaper, a high basis weight or a high rigidity sheet|seat is often used for a fastening tape part. Therefore, when the target portion to which the surface fastener is to be fixed shrinks, it tends to give the impression of the surface fastener and a foreign body feeling. Therefore, it is preferable not to overlap a front side waist elastic sheet and a target part, but to arrange a front side waist elastic sheet and a target part adjacently.

The front sheet which has a high basis weight part and a low basis weight part is arrange|positioned at least in the range from the area|region where a waist stretch sheet is arrange|positioned to the end part of the product longitudinal direction of a disposable diaper. The state of being arranged at least within the range from the region where the waist elastic sheet is arranged to the end in the product longitudinal direction of the disposable diaper means that the rear waist elastic sheet is covered and arranged from the rear waist elastic sheet to the disposable diaper. The state within the range of the rear end of the diaper and the state of covering the front waist elastic sheet and being arranged within the range from the front waist elastic sheet to the front end of the disposable diaper.

By using a front sheet having a high unit area weight part and a low unit area weight part, in the state where the waist elastic sheet is shrunk, the low unit area weight part is easy to shrink and the adjacent low unit area weight part and the high unit area weight part The state where the weight parts are close to each other. That is, in the natural state of a disposable diaper, the part where this top sheet is arrange|positioned becomes a bulkier state easily, and it becomes easy to realize a sense of thickness while maintaining a soft state. As a result, the difference in thickness can be made into the state which does not feel the difference in thickness further in the range from the end part of the product longitudinal direction of an absorber to the end part of the product longitudinal direction of a disposable diaper.

At least one of the front sheet and the outer sheet is made of a non-woven fabric sheet without thermal fusion points formed by point embossing and line embossing or a non-woven fabric with an area ratio of 5% to 15% of point embossing and line embossing. Spun cloth sheets are formed. In the top sheet and the exterior sheet formed of such a nonwoven fabric sheet, the degree of freedom of the fibers in the portion where no thermal fusion point is formed and the portion where embossing is not formed is high. Therefore, the part with a high degree of freedom of the fiber tends to be bulky in a natural state. As a result, the difference in thickness can be made into the state which does not feel the difference in thickness further in the range from the end part of the product longitudinal direction of an absorber to the end part of the product longitudinal direction of a disposable diaper.

The waist elastic sheet is bonded to the sheets arranged to sandwich the waist elastic sheet with an adhesive, and since the adhesive is applied intermittently, there are few joining points of the sheets. In a state where the waist elastic sheet is shrunk, the product thickness in the non-joint portion (portion to which the adhesive is not applied) becomes large and the flexibility is high.

The thickness of the product longitudinal direction edge part of an absorptive core is smaller than the thickness of the product longitudinal direction center of an absorptive core. The thickness gradually changes from the crotch portion of the disposable diaper toward the product longitudinal end of the absorbent body, and from the absorbent body toward the product longitudinal end of the disposable diaper. Users are less likely to feel the step feeling of disposable diapers.

(4) Other implementations

As mentioned above, although the content of this invention was disclosed through embodiment of this invention, it should not understand that the statement and drawing which make a part of this indication limit this invention. Various alternative embodiments, examples, and applied techniques will be apparent to those skilled in the art from this disclosure.

In a modified example, the front waist elastic sheet may be arranged so as to overlap the front end of the absorptive core 40a.

In a modified example, the front end of the back sheet may extend to the front end of the disposable diaper, or may be located behind the front end of the absorptive core. In a modified example, the rear end of the backsheet may extend to the rear end of the disposable diaper, or may be located on the front side of the rear end of the absorptive core.

In a modified example, the length of the side region in the product length direction may be the same as the length of the central region in the product length direction, or may be smaller than the length of the central region in the product length direction.

In a modified example, the rear end portion of the front waist elastic sheet may be arranged so as to overlap the front end portion of the target portion.

In a modification, you may add the pattern visually observable from the non-skin contact surface side of a disposable diaper to a backsheet. The pattern may be formed by printing, or by any one of embossing, thermal welding, and ultrasonic sealing.

The pattern is arranged in a region overlapping with the absorbent core. In addition, the pattern is not arranged between the front end of the disposable diaper and the front end of the absorbent core, and is not arranged between the rear end of the disposable diaper and the rear end of the absorbent core. The pattern is not arranged near the waist and is not arranged in a part where the color of the wearer's skin, etc., are easily permeable without an absorbent core. Therefore, it is possible to give an impression reminiscent of the waist circumference of underwear.

In a modified example, the top sheet may not be formed of a nonwoven fabric sheet having high basis weight portions and low basis weight portions alternately in the product width direction.

In a modified example, the front sheet may not be formed of a non-woven fabric sheet that does not have thermal fusion points formed by point embossing or line embossing, or may not be formed by point embossing or line embossing. The area ratio is 5% to 15%. % of non-woven sheets formed. In addition, the exterior sheet may not be formed of a non-woven fabric sheet that does not have thermal fusion points formed by point embossing or line embossing, or may not be formed of a non-woven fabric sheet having an area ratio of 5% to 15% of point embossing or line embossing. Spun cloth sheets are formed.

In a modified example, the adhesive for joining the waist elastic sheet and the sheets sandwiching the waist elastic sheet may not be intermittently arranged, but may be arranged on the entire surface.

In a modified example, the thickness of the end portions in the product longitudinal direction of the absorptive core may be the same as or thicker than the thickness of the product longitudinal center of the absorptive core.

As described above, of course, the present invention includes various embodiments and the like not described here. Therefore, the protection scope of the present invention is limited only by the technical features of the claims reasonably summarized according to the description.

In addition, the entire content of Japanese patent application 2013-156040 (July 26, 2013 application) is incorporated in this-application specification by reference.

Industrial availability

It is possible to provide a disposable diaper capable of suppressing dissatisfaction with respect to the burden on the skin and dissatisfaction with respect to appearance.

Explanation of reference signs

10. Disposable diaper; 20. Front waist region; 25. Inseam region; 30. Back waist region; 35. Leg opening; 40. Absorbent body; 40a. Absorbent core; 40b. Core cover; 50. Front sheet; 60, exterior sheet; 60a, back sheet; 70, side wings; 75, leg telescopic portion; 75F, front end; 75R, rear end; 77, auxiliary telescopic portion; 77F, front end ; 77R, rear end; 80, leg side pleats; 81, elastic member; 85, rear waist stretch; 85F, front end; 85R, rear end; 86, front waist stretch ; 86F, front side end; 86R, rear side end; 90, hook and loop; 91, substrate piece; 92, hook piece; 93, base; 94, extension; 95, target portion; 110, low Stiffness part; L, product length direction; W, product width direction.

Claims (9)

1. A disposable diaper comprising: a front waist region; a rear waist region; a crotch region between said front waist region and said rear waist region; a product length direction extending from said front waist region toward the rear waist region; a product width direction, which is perpendicular to the product length direction; an absorber, which spans the crotch region, and faces at least one of the front waist region and the rear waist region Extending, the absorbent body has an absorbent core; a pair of hook and loop fasteners, which are arranged on the outer end in the product width direction of the rear waist region, and are fixed to the front waist region; a target portion, which is arranged on the a front waist area for fixing the fastening tape; a waist elastic sheet spanning the center of the product width direction of the disposable diaper and having elasticity in the product width direction; The front waist region and the rear waist region extend along the product width direction for holding the disposable diaper on the body of the wearer, wherein, The waist elastic sheet is composed of a narrowed sheet, and has a rear waist elastic sheet arranged at a rear end of the rear waist region and a front waist elastic sheet arranged at a front end of the front waist region. , A part of the rear waist elastic sheet is arranged to overlap the rear end of the absorbent core and to overlap the waist holding part, The front waist stretch sheet is disposed adjacent to the front end of the absorbent core and the front end of the target portion, In the stretched state in which the disposable diaper is stretched, the rear end portion of the front waist stretch sheet has a center in the product width direction that extends toward the product length direction from the outer end portion in the product width direction. The curved shape is concave on the outside, The distance between the product width direction center of the front waist stretch sheet and the target portion in the product length direction is greater than the product width direction outer end portion of the front waist stretch sheet and the target portion. The distance in the length direction of the product is long. 2. The disposable diaper according to claim 1, wherein: The center of the product width direction in the region where the waist stretch sheet is arranged is defined as the central region, When the outer end in the product width direction of the region where the waist elastic sheet is arranged is defined as a side region, and the region between the central region and the side region is defined as a middle region, elongation in the product width direction of the central region is higher than the elongation in the product width direction of the middle region, The elongation rate in the product width direction of the said middle area|region is higher than the elongation rate of the said product width direction of the said side area|region. 3. The disposable diaper according to claim 1 or 2, wherein: In the natural state of the disposable diaper, the front end of the disposable diaper is at the center of the product width direction, and the product width direction outer end of the front end of the disposable diaper is toward the product. A shape that is indented on the inside in the longitudinal direction. 4. The disposable diaper according to claim 1 or 2, wherein: The disposable diaper includes a liquid-impermeable back sheet disposed on the non-skin-contacting side of the absorber, The front end of the back sheet is located between the front end of the disposable diaper and the front end of the absorbent core, The backside end part of the said back sheet is located between the backside end part of the said disposable diaper and the backside end part of the said absorptive core. 5. The disposable diaper according to claim 4, wherein: A pattern visually observed from the non-skin-contacting side of the disposable diaper is formed on the back sheet, The pattern is arranged in a region overlapping with the absorbent core and not arranged between the front end of the disposable diaper and the front end of the absorbent core and at the rear of the disposable diaper. end and the rear end of the absorbent core. 6. The disposable diaper according to claim 1 or 2, wherein: The disposable diaper includes a front sheet disposed on the surface of the disposable diaper on the skin-contacting side, The front sheet is arranged at least in the range from the region where the waist stretch sheet is arranged to the end of the disposable diaper in the product longitudinal direction, The top sheet is formed of a nonwoven fabric sheet having high basis weight portions and low basis weight portions alternately in the product width direction. 7. The disposable diaper according to claim 1 or 2, wherein: This disposable diaper includes: an exterior sheet disposed on the non-skin-contacting surface of the disposable diaper; and The front sheet is disposed on the surface of the disposable diaper on the skin-contacting side, At least one of the front sheet and the outer sheet is made of a non-woven fabric sheet without thermal fusion points formed by point embossing or line embossing or the area ratio of point embossing and line embossing is 5% to 5%. 15% non-woven sheet forming, At least one of the front sheet and the exterior sheet is arranged within a range from a region where the waist elastic sheet is arranged to an end in the product longitudinal direction of the disposable diaper. 8. The disposable diaper according to claim 1 or 2, wherein: The waist elastic sheet is bonded to sheets arranged to sandwich the waist elastic sheet with an adhesive, and the adhesive is intermittently applied. 9. The disposable diaper according to claim 1 or 2, wherein: The thickness of the edge part of the said product longitudinal direction of the said absorptive core is thinner than the thickness of the center of the said product longitudinal direction of the said absorptive core.