JP2002065733A - Shorts-type disposable diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shorts-type disposable diaper which has wide fit sizes and easy to make a person wear and which generates suited fastening force to secure sufficient fitting property. SOLUTION: As for the shorts-type disposable diaper 1, elastic members 71a and 71b around a waist are provided at a waist surrounding part D and are arranged so that intervals between the respective elastic members around the waist may be nearly equal being 3 to 20 mm. At regions D1 on an outer side than at least the both-side edges of an absorber 4, the members 71a and 71b are arranged and fixed in an expanded state so as to express expansion/ contraction elasticity. At at least the central part of a region where the absorber 4 exists, the members 71a and 71b are not arranged in the state of providing expansion/contraction elasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pants-type disposable diaper having a wide range of suitability for size and easy to wear.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 2-4364 discloses an elastic side panel provided at a side portion connecting a back portion and a ventral portion of a main body.
A pants-type diaper in which an elastic member is disposed at a waist opening of a main body is disclosed. However, in this pants-type diaper, a gap is easily generated in the waist opening and the leg opening. In addition, since the side panel is inferior in stretching stress characteristics, there is an inconvenience that the size suitability range is generally narrow.
Furthermore, in order to prevent the diaper from slipping off, it is necessary to increase the stretching stress of the side panel, which gives the wearer an unnecessary feeling of pressure, and also requires excessive force when the diaper is spread, Ease of putting on and putting on may also be impaired.

[0003] Japanese Patent No. 2602408 describes a pants-type disposable diaper in which an elastic member around the waist is joined so as to have a non-extended state portion and an extended state portion. In this diaper, a non-stretched portion is formed by bonding an elastic member to a back sheet with an adhesive in a non-stretched state. However, a large amount of adhesive is required to cause only a specific portion to be in a non-stretched state while the elastic member is being stretched, and a processing trouble is likely to occur. In addition, manufacturing costs are increased, and furthermore, the whole diaper is hardened by the adhesive and the texture is impaired. Moreover, it is difficult to control the stretched physical properties because the same elastic member realizes the opposite physical property states of the non-stretched state and the stretched state, and as a result, the tightening force on the wearer's body is not sufficiently generated. However, there are inconveniences such as the diaper coming off and conversely, the tightening force being too strong and compressing the wearer's body.

Accordingly, the present invention has a wide range of size suitability,
It is an object of the present invention to provide a pants-type disposable diaper that is easy to apply, generates an appropriate tightening force, secures a sufficient fitting property, hardly slips off, and has a clean appearance in a mounted state.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a liquid-permeable topsheet, a liquid-impermeable leak-proof sheet and a liquid-retentive absorber. In a pants-type disposable diaper having a plurality of waist elastic members arranged in a circumferential direction, the waist elastic members are arranged such that intervals between the waist elastic members are substantially equal to 3 to 20 mm. The waist elastic member is disposed and fixed in an extended state so that elasticity is exhibited, at least at a portion outside the both side edges of the absorber, and a portion where the absorber exists. The above object has been achieved by providing a pants-type disposable diaper which is not disposed at least in the central portion in a state where elasticity is developed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1 is a perspective view of one embodiment of the pants-type disposable diaper according to the present invention, and FIG. 2 (a) shows a state before assembling the diaper shown in FIG. 2B is a plan view, and FIG. 2B is a sectional view taken along line bb in FIG. 2A.

The disposable diaper 1 of this embodiment is of a pants type as shown in FIGS. 1 and 2, and has a liquid-permeable top sheet 2, a liquid-impermeable leak-proof sheet 3 and both sheets 2, 3.
A substantially vertically elongated absorbent body 10 having an absorbent core 4 as a liquid-retaining absorbent interposed therebetween, and an outer layer body 11 disposed on the leak-proof sheet 3 side of the absorbent body 10 It has.

The diaper 1 has an abdominal part A disposed on the abdomen of the wearer, a dorsal part B disposed on the dorsal side, and a crotch C located therebetween. Edges A1, A2 and back side B
Are joined to each other to form a waist opening 5 and a pair of leg openings 6. For this bonding, for example, a heat seal, a high frequency seal, an ultrasonic seal, or the like is used.

The topsheet 2, the leak-proof sheet 3 and the absorbent core 4 are joined to each other by predetermined means to form a vertically long absorbent body 10. The topsheet 2 and the leakproof sheet 3 are each rectangular. The absorbent core 4 is also rectangular. As the topsheet 2 and the leakproof sheet 3, the same as those conventionally used for this type of diaper can be used. The absorbent core 4 is composed of particles of a super absorbent polymer and a fiber material, and is covered with tissue paper (not shown).

As shown in FIG. 2, side cuffs 8, 8 made of a liquid-resistant or liquid-impermeable and air-permeable material are formed on both left and right sides of the absorber main body 10.
Each side cuff 8 has a fixed end and a free end along the longitudinal direction of the absorber main body 10. The fixed end is fixed to the topsheet 2. On the other hand, in the vicinity of the free end, a side cuff elastic member 81 is arranged in an extended state. As a result, the side cuffs 8 stand up, and the absorbent body 1
The outflow of the liquid in the width direction of 0 is prevented.

As shown in FIG. 2, the absorber main body 10 is fixed to the center of the outer layer body 11 with its longitudinal direction coinciding with the longitudinal direction of the outer layer body 11. The absorber main body 10 and the outer layer body 11 are partially joined and fixed. By fixing the two in this way, the absorbent core 4 described later can be used.
The occurrence of shirring is more effectively prevented.

The outer layer body 11 has at least two sheets, that is, an outer layer sheet 12 and an inner layer sheet 13 disposed on the inner surface side of the outer layer sheet 12. The two sheet materials are made of, for example, a nonwoven fabric. The outer layer body 11
The outer layer sheet 12 forming the outer shape of the diaper 1 forms the outermost surface of the diaper 1. The inner layer sheet 13 is joined to the inner surface of the outer layer sheet 12 by an adhesive such as a hot melt adhesive. Outer layer body 1
1 has an hourglass-like shape in which both side edges are inwardly confined at the center in the longitudinal direction.

The outer layer body 11 extends outward from the front and rear edges of the absorber body 10, and the extended portion is
It is folded back to the 0 side. Then, the front and rear edges of the folded outer layer material 11 are located on the absorbent core 4 in the absorber main body 10 as shown in FIG.

As shown in FIG. 2, a plurality of waist elastic members 51a and 51b are arranged at the front and rear ends of the outer layer body 11 along the front and rear edges along the width direction.
Each of the waist elastic members 51a and 51b is connected to the outer layer sheet 1.
2 and the inner layer sheet 13 are fixed in a stretched state. When the waist elastic members 51a and 51b are joined to each other, the two side edges A1 and A2 of the abdominal part A of the diaper 1 and the two side edges B1 and B2 of the back part B are joined together.
The end portions 1a and 51b are arranged so that the end portions substantially overlap each other. As a result, as shown in FIG. 1, the waist elastic members 51a and 51b are arranged in the circumferential direction of the waist opening 5 of the diaper 1, so that the waist opening 5
, A substantially continuous ring-shaped waist gather is formed.

As shown in FIG. 2, the elastic portions 61a, 61b
Is arranged. Each leg elastic member 61a, 61b
Is composed of a central portion 61a ', 61b' and each side edge portion 61a ", 61b" continuous therewith. The center portions 61a 'and 61b' are arranged so as to cross the crotch C of the diaper 1, and the side edge portions 61a "and 61b".
Are arranged along the curved portion. Each of the leg elastic members 61a and 61b includes an outer layer sheet 12 and an inner layer sheet 13.
The side edge portions 61a ", 61b" of the elastic members 61a, 61b are fixed to the sheets 12, 13 in an extended state by a predetermined joining means. Each of the leg elastic members 61a and 61b includes both side edges A1 and A2 of the abdominal portion A of the diaper 1 and both side edges B1 and B1 of the back portion B.
B2 and the two elastic members 61a,
61b are arranged so that the ends thereof overlap. Thereby, as shown in FIG. 1, substantially continuous ring-shaped leg gathers are formed near the leg openings 6, 6 of the diaper 1.

As the waist elastic member 51, the leg elastic member 61, and the side cuff elastic member 81, those formed of natural rubber, polyurethane resin, urethane foam resin, or the like in a strip shape or a thread shape are preferably used.
The waist elastic member has a strength of 10 to 1 when stretched by 30%.
00 gf, particularly preferably 15 to 80 gf,
It is preferable that the sheet is sandwiched and fixed between the outer layer sheet 12 and the inner layer sheet 13 at an elongation of 60 to 160%.
The extension ratio is the ratio of the length that has been increased by extension to the natural length.
When stretched to 0 cm, the stretch rate is set to 100%.

As shown in FIGS. 1 and 2, a plurality of body perimeters D located between the front and rear ends of the outer layer body 11 and the curved portions on both the left and right sides are provided with a plurality of pieces in the width direction of the outer layer body 11. The waist elastic members 71a and 71b are provided, respectively. Each waist elastic member 71a, 71b is in a thread shape,
In the abdominal part A and the dorsal part B, the outer sheet 12 and the inner sheet 13 are arranged at positions D1 outside the both side edges of the absorbent core 4 and extend and contract so as to exhibit elasticity. It is pinched and fixed. Each of the waist elastic members 71a and 71b is fixed using a known joining means such as an adhesive or a heat seal. Each waist elastic member 7
1a, 71b are both side edges A1, A of the abdominal part A of the diaper 1.
2 and the side edges B1 and B2 of the back side portion B are joined so that the ends of both elastic members 71a and 71b substantially overlap each other. As a result, as shown in FIG. 1, the waist elastic members 71 a and 71 b are arranged in the circumferential direction around the waist of the diaper 1.
In a portion D1 outside the both side edges of the absorbent core 4 in the above, a waist gather is formed in a region where the waist elastic members 71a and 71b are arranged.

The waist elastic members 71a and 71b are arranged such that the intervals between the elastic members are substantially equal.
However, some elastic members having different intervals from other members may be included as long as the effects of the present invention are not impaired. The distance between the elastic members is 3 to 20 mm, preferably 4 to 15 mm, and more preferably 5 to 10 mm. If the distance is less than 3 mm, it is difficult to control the processing, and there is a possibility that a plurality of elastic members may be integrated. When the elastic members are integrated, there is a possibility that a large stress is applied to the wearer's body to partially press the wearer, and the appearance of the diaper 1 becomes poor. If it exceeds 20 mm, the number of elastic members to be arranged is limited, so that the stress of each elastic member must be increased, and the body of the wearer is pressed. In addition, the distance between the gathers is too wide, and the appearance of the diaper 1 is not good.

Further, the waist elastic members 71a and 71b are
At least the central part of the portion where the absorbent core 4 exists is not arranged in a state where the elasticity is developed. That is, when the waist elastic members 71a and 71b are not arranged, or when the waist elastic members 71a and 71b are arranged, the waist elastic members 71a and 71b are arranged in a state where the elasticity does not appear. ing. In the present embodiment, the waist elastic members 71a and 71b are arranged such that one of the two inner ends thereof slightly overlaps the side edge of the absorbent core 4, and the absorbent core 4
The waist elastic members 71a and 71b are not arranged in the region from the center in the width direction to the vicinity of the left and right side edges. The waist elastic members 71a, 7 located on the side edges of the absorbent core 4
1b is in a non-stretched state and does not exhibit elasticity. As a result, no gathers are formed in the region of the diaper 1 where the absorbent core 4 is arranged.

On the absorbent core 4, the waist elastic members 71a and 71b are not disposed at all over the entire area in the width direction, or are disposed such that no elasticity is exhibited even if they are disposed. Is most preferable from the viewpoint of preventing the absorbent core 4 from being shirred as described below. But,
From the viewpoint of preventing the occurrence of shirring of the absorbent core 4, it is sufficient that there is at least a non-stretchable portion on the absorbent core 4, and at a rate of 60% or less, particularly 40% or less of the width of the absorbent core 4, Waist elastic members 71a and 71b exhibiting elasticity
May be arranged.

By arranging the waist elastic members 71a and 71b in this manner, the shirring of the absorbent core 4 is prevented, and the liquid absorbing area of the absorbent core 4 is effectively used. Further, due to this, it is difficult to form a gap between the wearer's body and the diaper 1, and leakage can be effectively prevented. In order to prevent the absorbent core from being shirred, the inner dimensions of the diaper may be matched with the girth of the wearer, and a means for stretching the girth elastic member to approximately the elongation rate may be considered, but in that case, the girth is too small. , Making it difficult to wear diapers. In addition, the configuration is such that the stress of the elastic member around the waist exhibits a maximum value when the diaper is worn with the inner size being the maximum, which is almost impractical.

As a result, even if the width of the absorbent core 4 is made narrower or thinner than that of the conventional diaper, the absorbent core 4 does not shrink due to the formation of excessive folds, and the same absorbent performance as that of the conventional diaper is exhibited. The material cost of the diaper 1 can be reduced. Specifically, the ratio of the width W2 (see FIG. 2) of the absorbent core 4 corresponding to the portion where the waist elastic members 71a and 71b are arranged to the product width W1 (see FIG. 2) of the diaper 1 is preferably set. 30-60%, more preferably 40-5
By setting it to 0%, more preferably 43 to 48%, sufficient absorption performance is exhibited, and material costs are reduced. These widths W1 and W2 are measured with the diaper 1 in an extended state. In the present embodiment, since the absorbent core 4 is rectangular, the width is the same in the longitudinal direction. However, when the width of the absorbent core 4 is not the same in the longitudinal direction, for example, When the sex core 4 has an hourglass shape, the width W2 is measured at a position corresponding to the portion where the waist elastic members 71a and 71b are arranged as described above.

The diaper 1 of the present invention also has the advantage that the appearance impression of the diaper 1 when worn is improved as a result of preventing the occurrence of shirring.

Preventing the absorbent core 4 from being shirred is particularly effective when the absorbent core 4 is thin and lightweight and has high flexibility. More specifically, the thickness of the absorbent core 4 is set to 0.
When it is 5 to 10 mm, especially about 0.5 to 5 mm, when the content of pulp fibers in the absorbent core 4 is 0 to 55% by weight, particularly about 0 to 30% by weight, or when the absorbent core 4 is soft Taber stiffness value as a measure of sex is 0.5 to 20 gf · cm, particularly 0.5 to 10 gf · cm
In the case of, the fit of the absorbent core 4 becomes particularly high, but conversely, the absorbent core 4 is liable to be shirred. However, by arranging the waist elastic members 71a and 71b in the above-described manner, even when the thin and lightweight absorbent core 4 that is easily deformed is used, the occurrence of shirring is effectively prevented. When the content of the pulp fiber in the absorbent core 4 is 0 to 55% by weight, the content of the superabsorbent polymer is preferably 40 to 100% by weight, particularly preferably 50 to 100% by weight. Further, a fiber material other than pulp fiber (for example, heat-fusible fiber) may be contained.

The Taber stiffness described above is determined by a stiffness test method (JIS P 8) using a paperboard Taber stiffness tester.
125). Specifically, the absorbent core 4 is cut into 3.8 × 7.0 cm together with the tissue paper wrapping it, and the measurement is performed using a Taber stiffness tester.

It is also possible to use an absorbent core in which no pulp fibers are used. For example, an absorbent core in which a highly absorbent polymer is dispersed in a nonwoven web can be used. The content of the nonwoven web at this time is 50 to
It is preferably 80% by weight, particularly preferably 60 to 75% by weight, and the content of the superabsorbent polymer is preferably 20 to 60% by weight, particularly preferably 30 to 50%.

From the viewpoint of wearing the diaper 1 around the wearer's waist with an appropriate tightening force, the waist elastic member 51 is used.
a, 51b and the waist elastic members 71a, 71b each have a stress σ _W when the waist opening 5 is stretched by 30%, and a stress σ _W when the waist peripheral portion D in which the waist elastic members 71a, 71b are arranged is stretched by 30%. It is preferable that they are arranged so as to be larger than the stress σ _D. In detail, σ _W is 1 of σ _D
It is preferable that it is up to 0 times, especially 1.5 to 6 times, from the viewpoint that more appropriate tightening force is generated. The measuring method of σ _W and σ _D will be described later.

For the values of σ _W and σ _D themselves, σ _W is 3
It is preferable that it is 0-250 gf / cm, especially 50-150 gf / cm, and it is preferable that (sigma) _D is 5-100 gf / cm, especially 10-40 gf / cm from the above-mentioned viewpoint.

Similarly, from the viewpoint of allowing the diaper 1 to be worn around the wearer's waist with an appropriate tightening force and preventing the diaper 1 from slipping off, the waist elastic members 51a, 51b are provided.
Indicates that the stress σ _W ′ per unit area when the waist opening 5 is stretched by 30% is 0.2 to 3 gf / cm ² , especially 0.8 to ² gf / cm ² .
It is preferable to arrange so that gf / cm ² may be obtained. For the same reason, the waist elastic members 71a and 71b are provided at the waist periphery D where the waist elastic members 71a and 71b are disposed.
Σ _D ′ per unit area at 30% elongation is 0.05
-3 gf / cm ² , particularly preferably 0.1-1 gf / cm ² . The measuring method of σ _W ′ and σ _D ′ will be described later.

Similarly, from the viewpoint of allowing the diaper 1 to be worn around the wearer's waist with an appropriate tightening force, the elasticity of the diaper 1 relative to the product width W1 in the portion D1 outside the both side edges of the absorbent core 4 is determined. The waist elastic member 71 which appears
The ratio of the arrangement width W3 + W4 of the a and 71b is preferably 40.
To 95%, more preferably 50 to 80%, and even more preferably 55 to 75%. If this ratio is less than 40%, the arrangement width is narrow, so that the elastic members 71a and 71b must be arranged at a high elongation rate in order to develop sufficient fitting properties. May partially compress the body of a person. This is the same problem as when a stretchable side panel is used in a pants-type disposable diaper. When the arrangement width of the waist elastic members 71a and 71b is different between the back part A and the abdominal part B of the diaper 1, the arrangement of the waist elastic members on at least one of the back part A and the abdominal part B is made. The ratio between the installation width and the product width of the diaper 1 may be within the above range, and the back part A and the abdomen B may be used.
In both cases, it is particularly preferable to be within the above range.

The diaper 1 of this embodiment is preferably manufactured by the method described below. First, the absorber main body 10 is manufactured according to a conventional method. On the other hand, to manufacture the outer layer body 11, first, a hot melt adhesive is applied over the entire surface of the outer layer sheet 12. Next, the outer layer sheet 1
The waist elastic members 71a and 71b are arranged and fixed in an extended state over the width direction of the second. Furthermore, the waist elastic member 51
a, 51b and the leg elastic members 61a, 61b are disposed and fixed to the respective target positions in an extended state. Thereafter, the inner layer sheet 13 is superposed on the outer layer sheet 12 and joined together, and then the waist elastic members 71a and 71b are cut at the center in the width direction to obtain the outer layer body 11. The thus obtained absorber body 10 and outer layer body 1
1 is fixed by partial joining, and the left and right side edges of the abdominal part A and the back part B in the outer layer body 11 are respectively joined and fixed to form a pants type.

For cutting the waist elastic member, a combination of cutting teeth and receiving teeth such as a rotary die cutter, a shear cutter, a pinch cutter and the like, a heat seal cut, an ultrasonic seal cut, a pressure contact cut, a water jet cutter and the like are known. Cutting means can be used.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the waist elastic members 71a,
71b is a portion D1 outside of both side edges of the absorbent core 4
Is arranged so as to exhibit the elasticity in almost the entire area, but instead of this, the elasticity may be exhibited only in a part.

The waist elastic members 71a and 71b are
The diaper 1 may be disposed only on the abdominal side A or the back side B
It may be arranged only in. When the waist elastic member is disposed on the abdominal part A, the appearance of the diaper when viewed from the front is clear. When the diaper is disposed on the back side B, there are advantages that the appearance of the diaper when viewed from behind is clear, that the tape for diaper disposal is easy to adhere, and that printing is easy to see.

In the above-described embodiment, the waist elastic members 71a and 71b are arranged at positions crossing the absorbent core 4. However, by shortening the length of the absorbent core 4, the absorbent core 4 A waist elastic member can be disposed over the entire width of the diaper 1 at a position between the front end or the rear end of the diaper 1 and the waist opening. As described above, when there is a plurality of waist elastic members that are located between the front end or the rear end of the absorbent core and the waist opening, the waist elastic members may be disposed so as to be entirely expandable and contractible. Alternatively, when an extension line is drawn from both side edges of the absorbent core 4 toward the waist opening, a portion located between the two extension lines is non-stretchable and a portion located outside thereof is stretchable. It may be arranged as possible.

In the above-described embodiment, in order to obtain the desired effect of the present invention, as a most preferable form, all the portions of the waist elastic members 71a and 71b that overlap the absorbent core 4 are non-stretchable. The waist elastic member 7 located on the absorbent core 4 as described above.
At least a part of 1a and 71b only needs to be non-stretchable, and there may be a part that exhibits stretchability. For the range to be non-stretchable, the width is about 1/2 or more of the width W2 of the absorbent core 4 for the pants-type diaper for infants,
Alternatively, it is preferable that the width of the diaper 1 is in a range of about 1/20 to 3/4 of the product width W1. For an underpants diaper for adults, about 1/3 of the width W2 of the absorbent core 4
Or about 1/20 of the product width W1 of the diaper 1
It is preferable to be in any range of at least 3/4.

[0037]

Examples [Examples 1 to 3 and Comparative Examples 1 and 2] FIG.
And the pants-type disposable diaper shown in FIG. 2 was manufactured. In the manufactured diaper, the distance between the waist elastic members, the stress σ _W when the waist opening is stretched by 30% and the stress per unit area σ _W ′, and 30 around the waist peripheral portion where the waist elastic members are provided. Table 1 shows the stress σ _D at% elongation and the stress σ _D ′ per unit area. Also, the diaper product width W
1. Width W2 of the absorbent core, width W3 of the waist elastic member
+ W4 is shown in Table 1 below. Further, the absorbent core Tab
The stiffness is shown in Table 1. In the diapers of Examples 1 to 3 and Comparative Examples 1 and 2, the intervals between the waist elastic members were substantially equal. Note that W1, W2 and W3 + W
4 was measured with the elastic member extended.

Comparative Example 3 A pants-type disposable diaper having elastic side panels described in JP-A-2-4364 was manufactured. In the manufactured diaper, the stress σ _W at the waist opening at 30% extension and the stress per unit area σ _W ′, and the stress at the waist periphery where the waist elastic member is disposed at 30% extension σ _D. Table 1 shows the stress σ _D ′ per unit area. Table 1 below shows the product width W1 of the diaper, the width W2 of the absorbent core, and the arrangement width of the side panels. In addition, Table 1 shows the Taber stiffness of the absorbent core. In addition, the arrangement width of W1, W2 and the side panel was measured in a natural state of the diaper.

In the diapers obtained in the examples and comparative examples, the stress σ _W at the time of 30% extension of the waist opening and the stress σ _W ′ per unit area, and the stress around the waist around which the waist elastic members are provided. The method for measuring the stress σ _D at 30% elongation and the stress σ _D ′ per unit area is as follows.

A waist opening is cut out over a width of 25 mm across the width of the diaper, and a ring-shaped measurement piece is collected. Similarly, over the width of the diaper, the circumference of the torso is 70 m wide.
m, and a ring-shaped measurement piece is collected. The test piece is loaded on a chuck of a tensile tester, pulled at a speed of 300 mm / min, and the stress at 30% elongation is measured. The measured stress was divided by the width (cm) of the measurement piece to calculate the stress per 1 cm, and the value was calculated by dividing the value by 3 at the waist opening.
The stress σ _W at the time of 0% elongation and the stress σ _D at the time of 30% elongation of the waist circumference where the waist elastic member is provided are defined.
The distance between the chucks is appropriately changed according to the width of the diaper.

The value of the stress measured by the above method is
The stress per 1 cm ² was calculated by dividing by the width (cm) of the measuring piece and twice (cm) the length of the measuring piece, and the value was calculated as the stress per unit area when the waist opening was stretched by 30%. σ _W ′ and stress σ _D ′ per unit area when the waist circumference where the waist elastic member is provided is extended by 30%. The reason for doubling the length of the measuring piece is that the measuring piece is ring-shaped, and that elastic members are disposed at the front and rear views of the diaper.

When the elastic member is provided only on one of the front body and the rear view of the diaper, in the above-described measurement of the stress, a measurement piece is collected only from the side on which the elastic member is provided.

The diapers obtained in Examples and Comparative Examples were evaluated for ease of squeezing, prevention of oppression, appearance and fit during wearing, and resistance to slipping by the following methods. Table 1 shows the results.

[Ease of squeeze] From the viewpoint of ease of spreading and pulling up diapers when ten diapers are applied to each of the examples and comparative examples with ten babies 16 to 24 months old as monitors. From the following criteria, ease of use was evaluated. A: It is easy to spread the diaper from the waist opening to the waist circumference before peeling, and it can be easily pulled up while maintaining the spread state. B: It is difficult to spread the diaper from the waist opening to the torso before peeling. C: It is difficult to spread the diaper from the waist opening to the waist circumference before peeling, and it is difficult to pull up.

[Prevention of Compression] The presence or absence of pressure on the body by the diaper was evaluated according to the following criteria. The procedure was the same as the above [Ease of staking]. A: There is no compression mark due to the elastic member on the body after taking off. B: There are some compression marks due to the elastic member on the body after taking off. C: There is a compression mark due to the elastic member on the body after taking off.

[Appearance and Fit during Wear] The quality of the fit of the diaper to the body and the appearance of the diaper during the wear were evaluated according to the following criteria. The procedure was the same as the above [Ease of staking]. A: The diaper is not sticky and the appearance is neat. B: The diaper is partially loose. C: The diaper is generally loose and does not fit the body.

[Difficulty of falling off] Evaluation was made using a dynamic walking model. A diaper was attached to this walking model, and the diaper was allowed to walk at a speed of 140 steps / min. A: The amount of displacement is less than 2 cm. B: The amount of displacement falls from 2 cm to less than 4 cm. C: The displacement drop amount is 4 cm or more.

[0048]

[Table 1]

As is clear from the results shown in Table 1, the diapers (products of the present invention) of each of the examples are easier to apply and do not give a feeling of oppression compared to the diapers of the comparative examples. In addition, the appearance in the attached state is good and the fit is excellent,
It turns out that it is hard to slip off. In Comparative Example 1,
The diaper is loose and does not fit easily and slips easily. In Comparative Example 2, in addition to this, there is an excessive feeling of pressure around the trunk. Comparative Example 3 which is a diaper having elastic side panels
Then, it is difficult to spread the diaper, there is an excessive feeling of pressure around the torso, and the diaper is likely to slip off.

[0050]

The pants-type disposable diaper of the present invention has a wide suitability for size, is easy to put on easily, generates an appropriate tightening force, secures a sufficient fit, and is hard to slip off. Further, the pants-type disposable diaper of the present invention has a neat appearance when worn. Further, according to the pants-type disposable diaper of the present invention, it is possible to reduce the material cost while maintaining the same absorption performance as the conventional diaper.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a pants-type disposable diaper according to the present invention.

2 (a) is a plan view of a state before assembling the diaper shown in FIG. 1 in an extended state as viewed from a top sheet side, and FIG. 2 (b) is bb in FIG. 2 (a). It is a line sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Leak-proof sheet 4 Absorbent core 10 Absorber main body 11 Outer layer body 71a, 71b Waist elastic member A Abdomen B Back side C Inseam Crotch D Body circumference

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jun Sasaki 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Prefecture F-term in the Kao Corporation Research Laboratories (Reference) 3B029 BD10 4C098 AA09 CC10 CC12 CC14 CC29 CE05 DD06 DD10 DD22

Claims (5)

[Claims] 1. A liquid-permeable topsheet, a liquid-impermeable leakproof sheet, and a liquid-retentive absorber, and are arranged circumferentially around a torso located around the wearer's torso. In a pants-type disposable diaper provided with a plurality of waist elastic members, the waist elastic members have an interval between each of the waist elastic members of three.
The waist elastic members are arranged and fixed in a stretched state at least at positions outside the side edges of the absorber so as to exhibit elasticity. A pants-type disposable diaper that is provided and is not disposed in a state where elasticity is developed at least in a central portion of a portion where the absorber is present. 2. A waist elastic member is arranged and fixed in a stretched state in a circumferential direction at a waist opening located around the waist of the wearer, and the waist elastic member and the waist elastic member are respectively provided. When the waist opening is stretched by 30%, the stress at the waist peripheral portion where the waist elastic member is disposed is 30%.
The pants-type disposable diaper according to claim 1, wherein the disposable diaper is arranged so as to be larger than the stress at the time of% elongation. 3. The waist elastic member and the waist elastic member each have a stress of 30 to 250 gf / cm when the waist opening is stretched by 30%, and the waist periphery where the waist elastic member is disposed. The pants-type disposable diaper according to claim 2, wherein the stress at the time of the 30% elongation of the part is 5 to 100 gf / cm. 4. The waist elastic member has a stress per unit area of 0.3% when the waist opening is stretched by 30%.
Arranged such that the 2~3gf / cm ^2, the waist elastic member, the stress per unit area at 30% elongation of the body-surrounding portion which the barrel hole elastic member is disposed is 0.05~3gf The pants-type disposable diaper according to any one of claims 1 to 3, wherein the pants-type disposable diaper is arranged so as to be / cm ² . 5. The pants-type disposable diaper according to claim 1, wherein the absorber has a Taber stiffness value of 0.5 to 20 gf · cm.