JP2008125627A - Pants type disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pants type disposable diaper excellent in an appearance, a wearing feeling and a slip-down preventing property. <P>SOLUTION: Both side edge parts of an abdominal side wrapping material 11A disposed at an abdominal side part A in an absorbent main body 10 and a back side wrapping material 11B disposed at a back side part B in the absorbent main body 10 are joined to form a side seal part, a waist opening and a leg opening. Both of the abdominal side wrapping material 11A and the back side wrapping material 11B have such structure that an outer layer sheet 12 and an inner layer sheet 13 composed of nonwoven fabric are laminated. At least one of the outer layer sheet 12 and the inner layer sheet 13 is composed of a stretchable sheet. The physical properties of the girth part of the abdominal side wrapping material 11A and the girth part of the back side wrapping material 11B are different. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pants-type disposable diaper.

  Elastic members made of thread rubber, flat rubber or the like are arranged in an expanded state at the waist opening or leg opening of the pant-type disposable diaper, and a stretchable waist gather or leg gather is formed. In such a configuration, the diaper is fixed to the wearer's body by a portion where the elastic member exists. Therefore, the contraction force acts intensively on the site where the elastic member exists, and the trace of the elastic member, that is, the so-called rubber mark is easily attached to the wearer's body. Moreover, many wrinkles generate | occur | produce in waist gathers or leg gathers by the contraction force of an elastic member. As a result, the fit of diapers is limited.

  In a disposable diaper configured to include an absorbent main body including an absorbent core and an outer packaging material bonded to the non-skin contact surface side of the absorbent main body, separately from the pants-type diaper having such a configuration, For the purpose of improving the fit of a diaper to a person, one using an elastic sheet as an outer packaging material is also known (see, for example, Patent Documents 1 and 2). According to such a disposable diaper, since it is not necessary to use a linear elastic member such as rubber thread in order to develop stretchability in the outer packaging material, the appearance and softness of the diaper before or during wearing is excellent. In addition, problems such as rubber marks at the time of wearing by a linear elastic body can be solved.

Japanese Patent Laid-Open No. 3-205053 Japanese Utility Model Publication No. 4-32718

  In the disposable diapers described in Patent Documents 1 and 2, the outer packaging material is divided into an abdominal outer packaging material located on the abdominal side of the absorbent main body and a dorsal outer packaging material located on the dorsal side. No special contrivance has been made with respect to the physical properties of the outer packaging material and the backside outer packaging material.For example, if an elastic sheet with a large elongation stress is used for the outer packaging material with emphasis on preventing diaper slippage, a feeling of pressure is generated around the stomach. On the other hand, there is a problem that the diaper is easily slipped off when using a stretchable sheet having a low elongation stress as the outer packaging material with an emphasis on the feeling of wearing.

  Therefore, the objective of this invention is providing the underpants type disposable diaper which can eliminate the trouble which the prior art mentioned above has.

  The present invention relates to a pants-type disposable diaper which is divided into an abdominal side portion located on the abdomen side of the wearer and a back side portion located on the dorsal side at the time of wearing, and a waist opening and a pair of leg openings are formed. An absorbent body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent body, and the outer packaging material is at least an abdomen in the absorbent body A ventral outer packaging material disposed on a side portion and a back outer packaging material disposed on a back side portion of the absorbent main body, both side edges of the ventral outer packaging material and the back outer packaging material They are joined together to form a pair of side seals, a waist opening and a pair of leg openings, and the ventral outer packaging material and the back outer packaging material are both an outer layer sheet and an inner layer sheet made of nonwoven fabric. And the outer layer sheet and By providing a pants-type disposable diaper in which at least one of the inner layer sheets is made of an elastic sheet, and the waistline portion of the abdominal outer packaging material and the waistline portion of the backside outer packaging material have different physical properties. The object has been achieved.

  According to the underpants-type disposable diaper of the present invention, it is excellent in appearance, wearing feeling, and slippage prevention.

Hereinafter, the underpants type disposable diaper of this invention is demonstrated, referring drawings based on the preferable one Embodiment (1st Embodiment).
A pants-type disposable diaper (hereinafter also referred to as a disposable diaper) 1 according to the present embodiment is divided into an abdominal side A located on the abdomen side of the wearer and a back side part B located on the back side when worn, and a waist opening 5 and a pair of leg openings 6 are formed. The disposable diaper 1 includes an absorbent main body 10 including an absorbent core 4 and an outer packaging material joined to the non-skin contact surface side of the absorbent main body 10. 11.

  The outer packaging material 11 includes at least a ventral outer packaging material 11A disposed on the ventral side portion A of the absorbent main body 10 and a back side outer packaging material 11B disposed on the back side portion B of the absorbent main body 10. ing. The outer packaging material 11 in the present embodiment includes an abdominal outer packaging material 11A and a back outer packaging material 11B. Then, both side edges of the ventral outer packaging material 11A and the back outer packaging material 11B are joined to each other, and as shown in FIG. 1, a pair of side seal portions S, a waist opening portion 5 and a pair of leg opening portions. 6 is formed.

  As shown in FIG. 3, the ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B both have a structure in which an outer layer sheet 12 made of a nonwoven fabric and an inner layer sheet 13 are laminated, and the outer layer sheet 12. At least one of the inner layer sheets 13 is made of an elastic sheet. Further, the trunk periphery 20A of the ventral outer packaging material 11A and the trunk periphery 20B of the back outer packaging material 11B have different physical properties.

  The disposable diaper 1 according to this embodiment will be further described. The absorbent main body 10 includes a liquid-permeable top sheet 2, a liquid-impermeable or water-repellent back sheet 3, and a liquid interposed between both sheets 2 and 3. It has a retentive absorbent core 4 and is formed substantially vertically. As shown in FIG. 3, the top sheet 2, the back sheet 3, and the absorbent core 4 have a rectangular shape, and are integrated to form a vertically long absorbent main body 10. As the surface sheet 2, the back surface sheet 3, and the absorptive core 4, the thing similar to what was conventionally used for this kind of diaper can be used, respectively. For example, as the absorptive core 4, what is comprised from the particle | grains and fiber material of a superabsorbent polymer, and coat | covered with the tissue paper (not shown) can be used.

  As shown in FIGS. 2 and 4, side cuffs 8 and 8 made of a liquid-resistant or water-repellent and breathable material are formed on both the left and right sides of the absorbent body 10 in the longitudinal direction. Yes. In the vicinity of the free end of each side cuff 8, a side cuff elastic member 81 is arranged in an extended state. Thereby, when wearing the disposable diaper 1 assembled as shown in FIG. 1, the side cuff 8 is erected by contracting the side cuff elastic member 81, and the width direction of the absorbent main body 10 is increased. Liquid outflow is prevented. As shown in FIGS. 3 and 4, the sheet material 82 for forming the side cuffs 8, 8 has a predetermined width portion 82 </ b> S on the outer side in the width direction of the absorbent main body 10, and the skin contact surface side of the back sheet 3. And is fixed between the absorbent core 4 and the back sheet 3.

  When further explaining the ventral outer packaging material 11A and the back outer packaging material 11B in the disposable diaper 1 of the present embodiment, as shown in FIG. 3, these are both an outer layer sheet 12 made of a stretchable sheet and a non-stretchable sheet. The inner layer sheet 13 is laminated. Both the outer layer sheet 12 and the inner layer sheet 13 are sheets made of nonwoven fabric. The outer layer sheet 12 forms the outer surface of the diaper. On the other hand, the inner layer sheet 13 is disposed on the inner surface side of the outer layer sheet 12. The stretchable sheet forming the outer layer sheet 12 only needs to have stretchability in at least the diaper width direction (the left-right direction in FIG. 2) when the diaper is in an unfolded state. The non-stretchable sheet that forms the inner layer sheet 13 does not have stretchability at least in the diaper width direction when the diaper is in a developed state.

  In the disposable diaper 1 of this embodiment, the same non-stretchable sheet is used for the ventral inner layer sheet 13A constituting the ventral outer packaging material 11A and the back inner layer sheet 13B constituting the back outer packaging material 11B. The abdominal side outer layer sheet 12A constituting the abdominal side outer packaging material 11A and the back side outer layer sheet 12B constituting the back side outer packaging material 11B use stretchable sheets having different physical properties. Specifically, the stretching stress in the width direction of the ventral outer layer sheet 12A is smaller than the stretching stress in the width direction of the back outer layer sheet 12B. Further, the air permeability of the back side outer layer sheet 12B is higher than the air permeability of the abdominal side outer layer sheet 12A.

  In the disposable diaper 1 according to the present embodiment, as described above, by changing the physical properties of the ventral outer layer sheet 12A and the dorsal outer layer sheet 12B, the entire waist portion 20A of the ventral outer packaging material 11A and the dorsal outer package are provided. The physical properties are different from those of the entire trunk portion 20B of the material 11B. That is, the stretching stress in the width direction of the waistline portion 20A of the abdominal outer packaging material 11A is different from the stretching stress in the width direction of the waistline portion 20B of the backside outer packaging material 11B, and the waistline of the backside outer packaging material 11B. The air permeability in the portion 20B is different from the air permeability in the waist portion 20A of the ventral outer packaging material 11A.

  In the disposable diaper 1 of the present embodiment, the stretching stress in the width direction of the waist portion 20A of the abdominal outer packaging material 11A is smaller than the stretching stress in the width direction of the waist portion 20B of the back side packaging material 11B. The air permeability at the waist portion 20B of the outer packaging material 11B is higher than the air permeability at the waist portion 20A of the ventral outer packaging material 11A.

The waist part 20A of the ventral outer packaging material 11A is a region between the longitudinal ends of the ventral outer packaging material 11A. When an elastic member made of thread rubber, flat rubber, or the like is provided, the elastic member is Does not include the allocated area. As will be described later, a waist elastic member 51 is disposed in the waist opening 5 as an elastic member in the ventral outer packaging material 11A in the present embodiment, and leg elastic members 61a and 61b are provided in the leg opening 6. Therefore, the waist part 20A of the ventral outer packaging material 11A does not include the region where the waist elastic member 51 is arranged and the region where the leg elastic members 61a and 61b are arranged.
The same applies to the waistline portion 20B of the backside outer packaging material 11B.

The stretching stress in the width direction of the ventral outer layer sheet 12A is preferably 50 to 150 cN, and more preferably 80 to 120 cN. Moreover, it is preferable that the extensional stress of the width direction of the back side outer layer sheet | seat 12B is 100-250 cN, and it is still more preferable that it is 150-200 cN.
The air permeability of the backside outer layer sheet 12B is preferably 1000 to 4000 cc / cm ² · s, and more preferably 1500 to 3000 cc / cm ² · s. Further, the air permeability of the ventral outer layer sheet 12A is preferably 500 to 2000 cc / cm ² · s, and more preferably 800 to 1500 cc / cm ² · s.

  In the disposable diaper 1 of this embodiment, as shown in FIG.1 and FIG.3, between the outer-layer sheet | seat 12 and the inner-layer sheet | seat 13 in each of the abdominal side outer packaging material 11A and the back side outer packaging material 11B, it is side seal part A1 ,. A2, B1, and B2 are joined to each other by heat sealing, high frequency sealing, or ultrasonic sealing, and the peripheral edge 50 of the waist opening 5 and the peripheral edge 60 of each of the pair of leg openings 6 are hot melt type. They are joined together by adhesives 52 and 62 such as adhesives. And between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in each of the abdominal side outer packaging material 11A and the back side outer packaging material 11B is not joined in the most part except these parts.

  Thus, since it was set as the structure which joined between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in the peripheral part 50 and 60 of each of the waist opening part 5 and a pair of leg opening part 6, it is the trunk periphery part of 11 A of ventral | abdominal outer packaging materials. The outer layer sheet 12 and the inner layer sheet 13 are hardly bonded to each other in the waist portion 20B of 20A and the backside outer packaging material 11B. Therefore, by making the physical properties of the ventral outer layer sheet 12A and the dorsal outer layer sheet 12B different, the trunk part 20A of the ventral outer packaging material 11A and the trunk of the back outer packaging material 11B are not affected by an adhesive or the like. The physical properties of the surrounding portion 20B can be made different.

  The area of the portion where the outer layer sheet 12 and the inner layer sheet 13 are not joined to each other in the ventral outer packaging material 11A and the back outer packaging material 11B is 60 with respect to the areas of the ventral side A and the back side B, respectively. It is preferably ~ 100%, more preferably 70-100%. Those satisfying this numerical value are referred to as “whole area or most part”.

  In the disposable diaper 1 of the present embodiment, as shown in FIG. 3, the outer layer sheet 12 and the inner layer sheet 13 are joined even in the central part in the diaper width direction of each of the abdominal outer packaging material 11A and the back outer packaging material 11B. Has been. Both sheets 12 and 13 are joined at a joint 14 having a predetermined width extending in the longitudinal direction of the diaper.

  As shown in FIG. 3, a plurality of waist elastic members 51 are provided at the peripheral edge 50 of the waist opening 5 in each of the ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B along the opening peripheral edge of the waist opening 5. , 51 are arranged. These waist elastic members 51 and 51 are fixed in an extended state between the outer layer sheet 12 and the inner layer sheet 13 via an adhesive 52.

  Further, the peripheral edge portions 60 and 60 of the leg opening 6 in the ventral outer packaging material 11A and the back outer packaging material 11B are provided with leg portions along the peripheral edge of the leg opening 6 as shown in FIGS. Partial elastic members 61a and 61b are arranged. These leg elastic members 61 a and 61 b are fixed in an extended state between the outer layer sheet 12 and the inner layer sheet 13 via an adhesive 62. As the waist elastic member 51 and the leg elastic members 61a and 61b, elastic materials such as natural rubber, polyurethane resin, foamed urethane resin, and hot melt elastic member are made into a thread (thread rubber) or a belt (flat), respectively. Those formed into (rubber) are preferably used.

  As for the absorptive main body 10, in the part except the both ends of the longitudinal direction, as shown in FIG.3 and FIG.4, only the center part of the width direction is 11A of stomach side outer packaging materials and the backside packaging material 11B by the main body junction part 15, respectively. The inner layer sheets 13A and 13B are joined. The main body joint portion 15 is a belt-like member extending in the longitudinal direction of the absorbent main body 10 and is provided at the central portion in the diaper width direction. When the width W2 of the main body bonding portion 15 is 70% or more of the width W of the absorbent main body 10, the absorbent main body 10 is unlikely to be peeled or broken during mounting.

  In the disposable diaper 1 of the present embodiment, both side edges A1, A2 of the ventral outer packaging material 11A and both side edges B1, B2 of the back outer packaging material 11B are joined to each other, as shown in FIG. An opening 5 and a pair of leg openings 6 are formed. By this joining, a pair of side seal portions S, S are formed on the left and right side edges of the disposable diaper 1 to form a pants shape. For these bondings, for example, heat sealing, high frequency sealing, ultrasonic sealing, or the like is used. In addition, a crotch part C is located between the abdominal side A and the back side B of the absorbent main body 10, that is, in the longitudinal center of the absorbent main body 10.

  In the disposable diaper 1 of the present embodiment, as shown in FIGS. 1 to 3, most of the ventral outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B are disposed on the ventral side portion A and the back side portion B, respectively. The crotch part C is not substantially present. Since the disposable diaper 1 has such a structure, when the wearer puts his / her leg into the leg opening 6 of the disposable diaper 1 or when the disposable diaper 1 is pulled up after putting the foot, the disposable diaper 1 is There is an advantageous effect that it is difficult to get caught on the wearer's foot or part of the body. That is, there is an advantageous effect that the disposable diaper 1 is easily put on.

The distance Lc (see FIG. 2) between the end on the center side in the longitudinal direction of the ventral outer layer sheet 12A and the end on the center side in the longitudinal direction of the back side outer layer sheet 12B is preferably 0 to 400 mm, and preferably 0 to 250 mm. More preferably, in order to obtain an advantageous effect that the disposable diaper 1 can be easily put on by providing the structure in which the ventral outer packaging material 11A and the back outer packaging material 11B do not exist in the crotch C, The distance Lc (see FIG. 2) between the end on the center side in the longitudinal direction of the side outer layer sheet 12A and the end on the center side in the longitudinal direction of the back outer layer sheet 12B is preferably 0 to 400 mm, and preferably 0 to 250 mm. More preferably.

  As shown in FIG. 2, the dimensions, ratios, etc. of each part described in this specification are the natural state (external force such as tension) in which the diaper is in an unfolded state and the contraction force by the elastic members of the waist opening and the leg opening is released. Or a value based on the value measured in a state in which the

  Next, the outer layer sheet | seat 12 which consists of a nonwoven fabric used for the stomach side outer packaging material 11A and the back side outer packaging material 11B of the disposable diaper 1 of this embodiment is demonstrated. The outer layer sheet 12 has elasticity as described above. “Stretchability” refers to an extensible sheet (a sheet that extends more than twice in length) having a maximum elongation of 100% or more in at least one direction and an elongation in one direction having a maximum elongation of 100% or more. It means that the elongation recovery rate (elongation recovery rate at 100% elongation) when stretched to 100% and then contracted is at least 70% or more. In the case of an elastic sheet having a plurality of directions having a maximum elongation of 100% or more, the elongation recovery rate may be 70% or more in only one of the directions.

  The outer layer sheet 12 can extend larger in the diaper width direction than in the diaper longitudinal direction (vertical direction in FIG. 2). More specifically, in the diaper width direction, it stretches greatly and contracts after stretching (maximum elongation of 100% or more and elongation recovery rate of 70% or more), but in the diaper longitudinal direction, it stretches only slightly (for example, , Maximum elongation of 50% or less).

  In the disposable diaper 1 of this embodiment, as described above, the physical properties of the ventral outer layer sheet 12A and the back outer layer sheet 12B are different. Specifically, the stretching stress in the width direction of the ventral outer layer sheet 12A is smaller than the stretching stress in the width direction of the back outer layer sheet 12B. The air permeability of the back side outer layer sheet 12B is higher than the air permeability of the abdominal side outer layer sheet 12A.

The elongation recovery rate of the elastic sheet is measured by the following measuring method.
[Method for measuring elongation recovery rate]
A sample piece of an elastic sheet having a length of 50 mm and a width of 25 mm is prepared, and the sample piece is fixed at a chuck interval K0 using a tensile tester ("Tensilon" RTC-1150A manufactured by Orientec Co., Ltd.) and 300 mm / min. After stretching to 100% stretched length K2 (K2 = K0 × 2) at the same speed, after starting to return at the same speed as the tensile speed, the length of the sample piece was restored after stretching. The length is K1. The elongation recovery rate at 100% elongation is calculated from the following equation.
Elongation recovery rate at 100% elongation (%) = [(K2−K1) / (K2−K0)] × 100

The elongation stress is measured by the following measurement method.
[Measurement method of elongation stress]
Sample pieces having a length of 50 mm and a width of 25 mm of the ventral outer layer sheet 12 </ b> A and the back outer layer sheet 12 </ b> B were prepared, and this sample was used as a chuck of Tensilon tensile tester [Orientec Co., Ltd., “RTC-1150”]. It fixes to a space | interval (30 mm in width) (The area | region which goes in 10 mm width direction inside from the width direction both ends of a sample is fastened with a chuck | zipper), and the load at that time is set to zero. Thereafter, the stress when the film is stretched at a speed of 300 mm / min until it becomes 1.7 times the natural length in the same direction as the diaper width direction is defined as an elongation stress.

The air permeability is measured by the following measuring method.
[Measurement method of air permeability]
Sample pieces of the ventral outer layer sheet 12A and the back outer layer sheet 12B are prepared, and this sample is stretched by 50% in the diaper width direction using an air permeability measuring device (KES-F8-AP1 manufactured by Kato Tech Co., Ltd.). Then, the ventilation hole is fixed so as to close the ventilation hole, and the ventilation resistance R (KPa · s / m) is measured. From the measured value of the airflow resistance R, the air permeability Q is calculated by the following equation.
Q = 12.5 / R (cc / cm ² · s)

  As the stretchable sheet forming the outer layer sheet 12, various sheets having stretchability can be used. For example, the outer layer sheet 12 is preferably formed of a nonwoven fabric made of thermoplastic fibers from the viewpoint of improving air permeability. In addition, the outer layer sheet 12 is preferably made of a laminated sheet from the viewpoint of improving the texture, and at least the layer on the non-skin contact surface side is formed of an air-through nonwoven fabric.

  More specifically, as the stretchable sheet forming the outer layer sheet 12, for example, (1) a sheet in which a stretchable fiber layer is integrated on both sides or one side of an elastic fiber layer, and (2) a net-like sheet A sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic sheet, (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic sheet, (4) An elastic nonwoven fabric sheet in which elastic fibers and stretchable fibers are mixed can be preferably used. Examples of the method of integrating the elastic fiber layer and the extensible fiber layer include, for example, laminating them and hydroentangled them, or entangled fibers by air-through, etc., heat embossing, adhesive, ultrasonic bonding, etc. The method of letting it be mentioned.

  As the sheet of (1), for example, (a) a substantially inelastic non-elastic fiber layer is disposed on at least one surface of the elastic fiber layer, and both fiber layers have a fiber form of the constituent fibers of the elastic fiber layer. In a state where the fibers are kept in contact with each other by thermal fusion at the intersection of the fibers, a part of the constituent fibers of the inelastic fiber layer has entered the elastic fiber layer and / or a part of the constituent fibers of the elastic fiber layer Examples include stretchable nonwoven fabrics that are in a state of entering into the inelastic fiber layer. Moreover, as said (1)-(3) sheet | seat, it has (b) the elastic layer which has elastic elasticity, and a substantially inelastic nonelastic fiber layer, and both the said layers are laminated | stacked on the thickness direction. A stretchable sheet obtained by stretching a partially bonded laminated sheet can be preferably used. As the sheet of (4), (c) a stretchable sheet obtained by stretching a sheet in which elastic fibers and substantially inelastic nonelastic fibers are mixed and partially joined can be used.

  The stretchable nonwoven fabric (a) will be described. At the interface between the elastic fiber layer and the non-elastic fiber layer and in the vicinity thereof, the intersection of the constituent fiber of the elastic fiber layer and the constituent fiber of the non-elastic fiber layer is heat-sealed, and it is bonded substantially uniformly over the entire surface. Has been. By joining all over, it is prevented that both layers are separated and a space is formed, and a stretchable nonwoven fabric having a multi-layer structure with a sense of unity, such as a single nonwoven fabric. "The state in which the constituent fibers of the elastic fiber layer maintain the fiber form" means that even if most of the constituent fibers of the elastic fiber layer are given heat, pressure, etc., the film or film-fiber structure A state that is not deformed. In the elastic fiber layer, the intersections of the constituent fibers are thermally fused in the layer. Similarly, in the non-elastic fiber layer, the intersection of the constituent fibers is thermally fused in the layer.

  When non-elastic fiber layers are arranged on both sides of the elastic fiber layer, at least one of the constituent fibers is in a state where a part of the constituent fibers enter the elastic fiber layer and / or one of the constituent fibers of the elastic fiber layer. The part is in a state of entering at least one of the inelastic fiber layers. In order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer, the constituent fibers of the elastic fiber layer and the constituent fibers of the non-elastic fiber layer are changed. It is preferable that at least one of the non-elastic fiber and the elastic fiber is in a web state (a state where heat fusion is not performed) before the heat fusion treatment. From the viewpoint of allowing the constituent fibers to enter other layers, the fiber layer in the web state is preferable because the short fibers have a higher degree of freedom than the long fibers.

  Moreover, it is preferable to use the air-through method in order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer. By using the air-through method, the constituent fibers can be made to enter the opposing fiber layer, and the constituent fibers can be easily made to enter from the opposing fiber layer. Further, by using the air-through method, it becomes easy to allow the constituent fibers of the inelastic fiber layer to enter the elastic fiber layer while maintaining the bulkiness of the inelastic fiber layer. In particular, when the constituent fibers of the inelastic fiber layer are entangled with the constituent fibers of the elastic fiber layer, it is preferable that they are entangled only by the air-through method. In order to entangle the fibers by the air-through method, the gas blowing pressure, the blowing speed, the basis weight and thickness of the fiber layer, the conveyance speed of the fiber layer, etc. may be adjusted appropriately. Preferably it is done.

  In the hot air treatment (particularly, the air-through method), a part of the constituent fibers of the non-elastic fiber web enters the elastic fiber web, and at the same time, the constituent fibers of the non-elastic fiber web and / or the constituent fibers of the non-elastic fiber web are elastic. The constituent fibers of the fiber web are heat-sealed at their intersections. In this case, care should be taken so that the constituent fibers of the elastic fiber web do not become a film or film-fiber structure by the hot air treatment.

  The elastic fiber layer has a property that it can be stretched and contracts when tension is released. The elastic fiber layer preferably has a residual strain of 20% or less, particularly 10% or less when contracted after 100% elongation in at least one direction parallel to the surface. This residual strain value is preferably satisfied at least in the diaper width direction, and more preferably in both the diaper width direction and the diaper longitudinal direction.

  The elastic fiber layer is an aggregate of fibers having elasticity. Examples of a method for forming an elastic fiber include a melt blown method in which a molten resin is extruded from a nozzle hole, and the extruded molten resin is elongated with hot air to thin the fiber, and a semi-molten resin is cooled with cold air. There is also a spunbond method in which stretching is performed by a mechanical draw ratio. As a special method of the melt blown method, there is a spinning blow method in which the spun bond method is combined with the melt blown method.

  The elastic fiber layer may be in the form of a web or a nonwoven fabric made of elastic fibers. For example, it may be a web or a non-woven fabric formed by a spinning blow method, a spun bond method, a melt blow method, or the like. Particularly preferred is a web obtained by the spinning blow method. As the constituent fiber of the elastic fiber layer, for example, a fiber made of thermoplastic elastomer, rubber or the like can be used. In particular, fibers made from thermoplastic elastomers can be melt-spun using an extruder in the same way as ordinary thermoplastic resins, and the fibers thus obtained are easily heat-sealed. Is suitable for stretchable nonwoven fabrics.

  Examples of the thermoplastic elastomer include styrene elastomers such as SBS, SIS, SEBS, and SEPS, olefin elastomers, polyester elastomers, and polyurethane elastomers. These can be used individually by 1 type or in combination of 2 or more types.

  The inelastic fiber layer has extensibility but is substantially inelastic. As used herein, extensibility refers to the case where the constituent fiber itself is stretched, and even if the constituent fiber itself is not stretched, the two fibers that have been heat-sealed at the intersection of the fibers are separated from each other, or the fibers are heat-sealed. For example, the three-dimensional structure formed by a plurality of fibers may be structurally changed, the constituent fibers may be broken, and the entire fiber layer may be elongated.

  Examples of the fibers constituting the inelastic fiber layer include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the inelastic fiber layer may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The inelastic fiber layer can be a continuous filament or short fiber web or nonwoven.

  The stretchable sheet (b) will be described. This stretchable sheet is a laminate sheet in which substantially inelastic nonelastic fiber layers are laminated on both sides or one side of an elastic layer having elastic stretchability, and these are partially joined in a regular pattern. It can be obtained by stretching.

  This laminated sheet is manufactured as follows, for example. On the fiber web (first inelastic fiber layer) supplied from the card machine, an elastic fiber is supplied to form an elastic layer, on which another card machine or fiber web (second inelastic fiber layer) is formed. Fiber layer). The obtained laminated sheet having a three-layer structure is subjected to hot air treatment by an air-through dryer. The laminated sheet after the hot air treatment is subjected to hot embossing by an embossing device including an embossing roll in which embossing convex portions are regularly arranged on the peripheral surface and an anvil roll arranged to face the embossing roll. In addition, although the hot air process with a dryer is performed for the purpose of the heat | fever fusion | bonding of an elastic fiber and a non-elastic fiber, and the penetration | invasion of a fiber, this hot air process can also be abbreviate | omitted.

  The elastic layer preferably includes elastic fibers made of an elastic material. Examples of the elastic material include thermoplastic elastomers, rubbers, ethylene / propylene copolymers, and the like. Among these, thermoplastic elastomers are preferable because a fibrous elastic body can be formed relatively easily. Examples of the thermoplastic elastomer include polyurethane, styrene (SBS, SIS, SEBS, SEPS, etc.), olefin (copolymers such as ethylene, propylene, butene, etc.), vinyl chloride, and polyester. These can be used individually by 1 type or in combination of 2 or more types. The content of elastic fibers made of an elastic material in the elastic layer is preferably 50 to 100% by weight, particularly 75 to 100% by weight. As an elastic layer, it can replace with what consists of a fiber layer, and a film-like thing, a net-like thing, etc. can also be used. As the film or net forming material, the above-mentioned various elastic materials can be used.

  The stretchable sheet (c) will be described. In this stretchable sheet, elastic fibers and stretchable fibers are independently introduced into the same die, and simultaneously discharged independently from different nozzles arranged on the die, and the melt-spun fibers are cooled by cooling air. It is obtained by drawing with post-drawing air, depositing the resulting mixed fibers in a web shape, partially fusing the deposit with a hot embossing roll, and drawing the partially fused mixed fibers.

  Next, the non-stretchable sheet which forms the inner layer sheet | seat 13 which consists of a nonwoven fabric used for 11A of stomach side outer packaging materials and the backside packaging material 11B of the disposable diaper 1 of this embodiment is demonstrated. The non-stretchable sheet refers to a sheet having an elongation recovery rate (%) measured by the above [Method for measuring elongation recovery rate] of 20% or less, or a sheet that breaks before elongating 100%. The non-stretchable sheet may or may not have extensibility, but the maximum elongation is preferably 90% or less.

  As the non-stretch sheet, a nonwoven fabric, a laminated material of a nonwoven fabric and a resin film, a porous film, and the like are preferable. The non-stretch sheet is preferably formed from a nonwoven fabric made of thermoplastic fibers from the viewpoint of improving air permeability and texture, and is formed from a water-repellent nonwoven fabric from the viewpoint of preventing excrement leakage. Are preferred.

  Since the outer layer sheet 12 is generally lower in sheet strength than the inner layer sheet 13, the abdomen outer packaging material 11A and the back outer packaging material 11B are torn at the time of use, or when the diaper is worn, the outer packaging material is mistaken for a finger. There is a risk of breaking through 11 or the like. In order to prevent these, the sheet strength of the inner layer sheet 13 is preferably high, and the breaking strength in the diaper width direction and the diaper longitudinal direction is preferably 5 N / 25 mm or more. The breaking strength is measured by the following measuring method.

[Measurement method of breaking strength]
Prepare a sample with a length of 50 mm and a width of 25 mm, set the sample at 30 mm between the chucks, conduct a tensile test at a test speed of 300 mm / min, and use the maximum point load obtained at that time in the diaper width direction and diaper length. The breaking strength in the direction.

  From the viewpoint of breaking strength, air permeability, and prevention of adhesive bleeding, it is preferable to use a nonwoven fabric obtained from a production method such as spunbond or heat roll as the inner layer sheet 13.

The disposable diaper 1 of the present embodiment is excellent in wearing feeling and slip-off preventing property because the physical properties of the waistline portion 20A of the ventral outer packaging material 11A and the waistline portion 20B of the backside outer packaging material 11B are different. .
That is, since the stretching stress in the width direction at the waist portion 20A of the abdominal outer packaging material 11A is smaller than the stretching stress at the waist portion 20B of the back side outer packaging material 11B, there is no feeling of pressure around the stomach and the slippage is not easily lost. In addition, since the moisture permeability at the waist portion 20B of the backside outer packaging material 11B is higher than the moisture permeability at the waist portion 20A of the abdominal outer packaging material 11A, the moisture permeation and rash caused by night sweats, particularly when sleeping on the back. Can be reduced.

  Moreover, in the disposable diaper 1 of this embodiment, as shown in FIGS. 1-3, the abdominal side outer packaging material 11A and the back side outer packaging material 11B are mostly in the abdominal side part A and the back side part B, respectively. The crotch part C is not substantially present. Since the disposable diaper 1 has such a structure, when the wearer puts his / her leg into the leg opening 6 of the disposable diaper 1 or when the disposable diaper 1 is pulled up after putting the foot, the disposable diaper 1 is There is an advantageous effect that it is difficult to get caught on the wearer's foot or part of the body. That is, there is an advantageous effect that the disposable diaper 1 is easily put on.

  Next, the suitable manufacturing method of the underpants type disposable diaper of the said embodiment is demonstrated. This manufacturing method is a method for continuously manufacturing the pants-type disposable diaper 1 of the embodiment. In this manufacturing method, as shown in FIG. 5, the outer layer sheet 12 expanded in the width direction is joined to the inner layer sheet 13 expanded in the width direction to form the ventral outer packaging material and the back outer packaging material. Then, the inner layer sheet 13 and the absorbent main body 10 in these outer packaging materials are joined by a main body joining portion (not shown) while maintaining the stretched state of the outer layer sheet 12 in these outer packaging materials, and then these outer packagings This is a method for manufacturing a pants-type disposable diaper in which the extension force of the material to the outer layer sheet 12 is released and the outer layer sheet 12 is contracted by the contraction force.

  This manufacturing method will be described in detail. The first belt-like sheets 120A and 120B are used as the raw fabric of the outer layer sheet 12, and the second belt-like sheets 130A and 130B are used as the raw fabric of the inner layer sheet 13. 1st strip | belt-shaped sheet | seat 120A, 120B is a strip | belt-shaped stretchable sheet which has a stretching property in the longitudinal direction. The second belt-like sheets 130A and 130B are belt-like non-stretchable sheets that do not substantially extend in the longitudinal direction.

  As the first belt-like sheets 120A and 120B, sheets manufactured in advance as a belt-like sheet having stretchability in the longitudinal direction outside the diaper production line can be used, but in this production method, as shown in FIG. In addition, before the step of extending the first belt-like sheets 120A and 120B in the longitudinal direction, the non-stretchable belt-like sheets 120A ′ and 120B ′ are processed to obtain the first belt-like sheets 120A and 120B that exhibit the stretchability. Or a step of obtaining the first belt-like sheets 120A, 120B with improved stretchability by processing the low-stretch belt-like sheets 120A ′, 120B ′, and the first belt-like sheets 120A, A thus obtained. 120B is extended.

  In the present manufacturing method, the process for developing the stretchability or the process for improving the stretchability is an inline process using a pair of tooth groove rolls 71 and 71 in which teeth and grooves mesh as shown in FIG. More specifically, the belt-like sheets 120A ′ and 120B ′ in which the non-elastic fiber layers are integrated on both sides or one side of the elastic layer made of an elastic fiber layer, a net-like elastic sheet, an elastic film, or the like are used as a pair of tooth spaces. It is difficult to inhibit expansion and contraction of the elastic layer by biting into the rolls 71 and 71, thereby breaking the non-elastic fiber layer, extending the constituent fibers, or destroying the heat-sealing points between the fibers. The structure is changed. By changing the non-elastic fiber layer into a structure that hardly inhibits the expansion and contraction of the elastic layer, the first belt-like sheets 120A and 120B that exhibit or improve the stretchability are obtained.

  In this way, before the step of extending the first belt-like sheets 120A, 120B in the longitudinal direction, the non-stretchable or low-stretch belt-like sheets 120A ′, 120B ′ are processed inline to develop stretchability. Or by providing the process which raises a stretching property, the stretching property equivalent to the sheet | seat manufactured previously as a strip | belt-shaped sheet | seat which has a stretching property in a longitudinal direction outside a diaper manufacturing line is obtained. The width of the non-stretchable or low stretchable belt-like sheets 120A ′ and 120B ′ is set to 100 to 180% of the width of the first belt-like sheets 120A and 120B in consideration of the shrinkage of the width when processed inline. It is preferable to set it to 120 to 160%.

In order to make the stretching stress of the first belt-like sheet 120A different from the stretching stress of the first belt-like sheet 120B, the first belt-like sheets 120A and 120B having different stretching stress in the material state (unprocessed) are used, or by in-line machining. What is necessary is just to obtain 1st strip | belt-shaped sheet | seat 120A, 120B from which a stretching stress differs.
In order to make the air permeability of the first belt-like sheet 120A different from the air permeability of the first belt-like sheet 120B, the first belt-like sheets 120A and 120B having different air permeability in the material state (unprocessed) are used, or by in-line processing What is necessary is just to obtain 1st strip | belt-shaped sheet | seat 120A, 120B from which air permeability differs.

  In this manufacturing method, the first belt-like sheets 120A and 120B obtained as described above are stretched between the first nip roll 72 and the second nip roll 73 while being continuously conveyed. Each of the first nip roll 72 and the second nip roll 73 is composed of a pair of rolls, and the rotational speed (peripheral speed, sheet thickness) of the pair of rolls constituting the second nip roll 73 rather than the pair of rolls constituting the first nip roll 72. Driven to increase the feed rate). The pair of turning rolls 75a and 75a turns the first belt-like sheets 120A and 120B extended so as to join the second belt-like sheets 130A and 130B.

  Next, the second belt-like sheets 130A and 130B (inner layer sheet 13) expanded in the width direction and the first belt-like sheets 120A and 120B (outer layer sheet 12) expanded in the width direction are bonded and bonded together. . Since the second belt-like sheets 130A and 130B are non-stretchable sheets and the first belt-like sheets 120A and 120B are stretchable sheets, the second belt-like sheets 130A and 130B in a substantially non-stretched state, The first belt-like sheets 120A and 120B in a state where the shrinkage is developed are bonded together.

  In the present manufacturing method, the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B are bonded between the first belt-like sheet 120A and the second belt-like sheet 130A as shown in FIG. The leg elastic member 61a and the waist elastic member 51 are sandwiched, and the leg elastic member 61b and the waist elastic member 51 are sandwiched between the first belt-like sheet 120B and the second belt-like sheet 130B. .

  Specifically, before superimposing the first belt-like sheet 120A and the second belt-like sheet 130A, either one of the first belt-like sheet 120A and the second belt-like sheet 130A or a predetermined part on the opposing surface of both are provided. The adhesive members 52 and 62 for fixing the elastic members are applied, and the elastic members 61a and 51 are sandwiched in an expanded state, and the first belt-like sheet 120A and the second belt-like sheet 130A are paired with a pair of nip rolls 74, 74, the elastic members 61a and 51 are fixed and the first belt-like sheet 120A and the second belt-like sheet 130A are joined. The same applies to the joining of the first belt-like sheet 120B and the second belt-like sheet 130B.

  The leg elastic members 61a and 61b are moved between the belt-like sheets 120A and 130A and between the belt-like sheets 120A and 130B while being swung by a known rocking guide in a direction perpendicular to the flow direction of the belt-like sheets 120A, 120B, 130A and 130B. Introduce. The turning roll 75b turns the conveying direction of the belt-like sheets 130A and 130B in a predetermined direction. By bonding the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B, the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B that are limited in the extent of extension in the longitudinal direction are obtained. The pair of turning rolls 75c and 75c turn the conveying direction of the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B in a predetermined direction.

  In this manufacturing method, the first belt-like sheets 120A and 120B are bonded to the second belt-like sheets 130A and 130B in a state where the first belt-like sheets 120A and 120B are elongated in the longitudinal direction. Is joined to the second belt-like sheets 130A and 130B in a state where the sheet is small (so-called width-reduced state). Therefore, the first belt-like sheets 120A and 120B used as the raw sheet of the outer layer sheet 12 take into account the width shrinkage due to the elongation, and the width before the longitudinal stretching (the same as the width in the non-stretched state) is the second belt-like sheet. The use of 100 to 140% of the width of the first belt-like sheets 120A and 120B after being joined to 130A and 130B means that the first belt-like sheets 120A and 120A are stretched in the longitudinal direction due to the width shrinkage caused by the stretching. From the viewpoint of preventing the width of 120B from becoming smaller than the width of the second belt-like sheets 130A and 130B, it is more preferable to use 110-130%. The elongation ratio of the first belt-like sheets 120A and 120B when being joined to the second belt-like sheets 130A and 130B is, for example, 1.3 to 1.4 times, and more preferably 1.5 to 3.0 times.

  The pants-type disposable diaper 1 of the above embodiment is a conventional so-called cross-flow type pants-type disposable diaper except that the abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B obtained as described above are used. It can be manufactured in the same manner as the manufacturing method. For example, as shown in FIG. 5, the absorbent main body 10 obtained by cutting the absorbent main body continuous body 101 on the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B, respectively, in the flow direction. After 90 degrees rotation, the adhesive is fixed intermittently. Further, the diaper continuous body 100 is obtained by removing the semicircular trim 111 for forming the leg opening by a rotary cutter, a laser cutter, or the like.

  The abdomen outer wrapping material continuous body 110A and the back wrapping material continuous body 110B are fixed to the absorbent main body 10 while maintaining the stretched state of the first belt-like sheets 120A and 120B. In other words, the absorbent main body 10 is fixed while maintaining the abdomen outer wrapping material continuous body 110 </ b> A and the back wrapping material continuous body 110 </ b> B so as not to shrink due to the contraction force of the first belt-like sheets 120 </ b> A and 120 </ b> B. Next, the side portions 12a and 12b of the abdomen outer wrapping material continuum 110A and the back side wrapping material continuum 110B in the diaper continuum 100 are folded back so as to cover both ends of the absorbent main body 10, and the absorbent main body 10 After fixing each side part 12a, 12b of 110A of belly side outer packaging material continuous bodies and 110B of back side outer packaging material continuous bodies to both ends, the diaper continuous body 100 is folded in two. Next, after forming the side seal portions S and S by heat seal, ultrasonic seal, high frequency seal or the like, or simultaneously with forming the side seal portions S and S, the pants type disposable diaper is cut. 1 can be obtained.

  For example, a method described in JP-A-4-166150 is used as a method of rotating the absorbent main body 10 by 90 degrees and intermittently fixing the absorbent main body 10 on the abdomen outer wrapping material continuous body 110A and the back side outer wrapping material continuous body 110B. Can do. The main body joint (not shown) for fixing the absorbent main body 10 to the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B includes the absorbent main body 10, the ventral outer packaging material continuum 110A and the back side. It can be applied to either one or both of the outer packaging material continuous body 110B.

  According to this manufacturing method, in this way, using the belt-like sheet having the stretchability in the longitudinal direction (first belt-like sheets 120A and 120B), good stretchability in the diaper width direction (left-right direction in FIG. 2). A pants-type disposable diaper having high finishing accuracy can be produced stably and continuously.

  That is, even if the first belt-like sheets 120A and 120B are sheets having excellent stretchability in the longitudinal direction, the first belt-like sheets 120A and 120B are obtained by pasting them together with the second belt-like sheets 130A and 130B that are substantially not stretched. The abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B that are formed are hardly stretched any more, or are slightly stretched when they are slightly stretched (so-called stretched growth). Therefore, if the abdomen outer wrapping material continuum 110A and the back wrapping material continuum 110B are transported with a certain degree of tension, the tension applied to the abdominal wrapping material continuum 110A and the back wrapping material continuum 110B during transportation. Even if fluctuates, fluctuations in the amount of elongation (elongation rate) of the ventral outer packaging material continuum 110A and the back outer packaging material continuum 110B are unlikely to vary.

  Therefore, for example, (b) a position where the trims 111A and 111B are cut out from the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B, and (b) the ventral outer packaging material continuous body 110A and the back outer packaging material continuous body 110B. The joint position when the absorbent main body 10 is joined, (c) the folding position when the diaper continuous body 100 is folded in half, (d) the ventral outer packaging material continuous body 110A fixed to the absorbent main body 10 and the back. Deviation may occur in the sealing position when forming a side seal S by sealing a predetermined portion of the side outer packaging material continuous body 110B, (e) the cutting position when cutting and dividing the diaper continuous body 100 into individual diapers, and the like. A pants-type disposable diaper that is prevented and has high finishing accuracy can be manufactured stably.

  In addition, by partially joining the first belt-like sheets 120A and 120B and the second belt-like sheets 130A and 130B, the abdomen outer wrapping material continuous body 110A and the back side derived from the stretchability of the first belt-like sheets 120A and 120B. Even if the stretchability of the outer wrapping material continuous body 110B is not impaired by the adhesive, or even if it is impaired, the degree is slight, so that the obtained disposable diaper 1 has the stretchability of the first belt-like sheets 120A and 120B. The abdomen outer wrapping material 11A and the back wrapping material 11B extend and contract well in the diaper width direction (left-right direction in FIG. 2), exhibiting a good fit to the wearer's waist, and preventing wearing and leakage prevention Excellent in properties.

  In the manufacturing method shown in FIG. 5, the first belt-like sheets 120 </ b> A and 120 </ b> B, which are the original fabric of the outer layer sheet 12, are stretched in the longitudinal direction, and then the original fabric of the inner layer sheet 13 remains in a long shape. Although it has joined to 2nd strip | belt-shaped sheet | seat 130A, 130B, methods other than this are also employable. For example, the first belt-like sheets 120A and 120B are stretched in the width direction, intermittently cut, and then the short objects sequentially generated by the intermittent cutting are connected after being rotated 90 degrees, After forming a long sheet having elasticity in the direction (flow direction), it can be joined to the second belt-like sheets 130A and 130B. As a method (or mechanism) for rotating the short object by 90 degrees, a known method (or mechanism) can be used. Short objects are connected to each other by arranging adjacent short objects so that the end portions in the flow direction overlap each other, and processing such as heat sealing, ultrasonic sealing, and high frequency sealing is performed on the overlapping portions. Can be done.

  Also in such a manufacturing method, a 1st strip | belt-shaped sheet is extended | stretched between the 1st nip roll 72 and the 2nd nip roll 73, and it bonds and bonds with a 2nd strip | belt-shaped sheet in that state. And by using the abdominal-side outer packaging material continuum and the back-side outer packaging material continuum obtained as described above, a pants-type disposable diaper can be stably and continuously produced as in the manufacturing method shown in FIG. .

Next, with reference to FIG. 6, 2nd Embodiment of the underpants type disposable diaper of this invention is described.
Here, FIG. 6 is a plan view showing a developed state of the pants-type disposable diaper according to the second embodiment of the present invention. In the following description, differences from the pant-type disposable diaper of the first embodiment will be mainly described, and the description of the pant-type disposable diaper of the first embodiment will be appropriately applied to the same points.

In the pant-type disposable diaper of the second embodiment, as shown in FIG. 6, the abdomen outer packaging material 11 </ b> A and the back outer packaging material 11 </ b> B are joined at the crotch C. In the pants-type disposable diaper of this embodiment, the abdominal outer packaging material 11A and the back outer packaging material 11B are in contact with each other at the crotch portion C. That is, the distance Lc between the end portion on the center side in the longitudinal direction of the ventral outer layer sheet 12A and the end portion on the center side in the longitudinal direction of the back side outer layer sheet 12B is 0 mm.
The abdominal outer packaging material 11A and the back outer packaging material 11B may overlap each other in the crotch portion C.
As in the second embodiment, the form in which the ventral outer packaging material 11A and the back outer packaging material 11B are joined at the crotch C is, for example, the abdominal outer packaging material 11A and the back outer packaging material 11B in the material state. It is possible to manufacture by bonding with the above or by in-line processing.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment.
In the embodiment of the present invention, the physical properties of the waist layer portion 20A of the ventral outer packaging material 11A and the waist portion 20B of the back side outer packaging material 11B are made different by making the physical properties of the outer layer sheet 12 different. By changing the physical properties of the sheet 13, the physical properties of the waistline portion 20A of the ventral outer packaging material 11A and the waistline portion 20B of the backside outer packaging material 11B may be made different. Alternatively, the physical properties of both the outer layer sheet 12 and the inner layer sheet 13 may be different. As described above, when the physical properties of the inner layer sheet 13 are made different, the above-described descriptions relating to the various physical properties in the outer layer sheet 12 are appropriately applied to the various physical properties in the inner layer sheet 13.
In the embodiment of the present invention, the inner layer sheet 13 made of a non-stretchable sheet is made of two sheets, a ventral inner layer sheet 13A and a back inner layer sheet 13B, but the inner layer made of a non-stretchable sheet. The sheet 13 may be formed from a single sheet.

  Moreover, the coating shape of the joining part 14 which joins the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in the part except the peripheral parts 50 and 60 of the side seal part S and the waist opening part 5 and the leg opening part 6 is the said implementation. The shape of the coating is not limited to the coating shape (coating shape over the entire length in the central portion in the width direction), for example, the discontinuous (intermittent) coating shape in the longitudinal direction, only the central portion in the longitudinal direction or the longitudinal direction A coated shape in which only both ends in the direction are coated may be used. Further, the joint portion 14 may not be provided.

Further, the bonding between the outer layer sheet 12 and the inner layer sheet 13 is not limited to bonding using an adhesive, and can be achieved by general bonding by heat (embossing, ultrasonic sealing, etc.).
Further, the joining or engaging position between the both side edges A1, A2 of the ventral outer packaging material 11A and the both side edges B1, B2 of the back outer packaging material 11B is not limited to the position just beside the body, but slightly forward or rearward of the body. It may be a close position.
Further, on the non-skin contact surface side (outer layer sheet 12 side) of the stomach side outer packaging material 11A or the back side outer packaging material 11B of the disposable diaper 1 described above, it is disposed at a position overlapping with the joining portion 14 such as a hot melt adhesive. By fixing the tape, the disposable diaper 1 that can be disposed of in a compact manner while maintaining the stretchability of the disposable diaper 1 can be obtained.

FIG. 1 is a perspective view showing a pants-type disposable diaper according to a first embodiment of the present invention. FIG. 2 is a plan view showing a developed state of the pants-type disposable diaper shown in FIG. FIG. 3 is an exploded perspective view of the pants-type disposable diaper shown in FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a perspective view showing one manufacturing method of the pants-type disposable diaper of the present invention. FIG. 6 is a plan view (corresponding to FIG. 2) showing a developed state of the pants-type disposable diaper according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent core 5 Waist opening 6 Leg opening 10 Absorbent main body 11 Outer packaging material 11A Abdominal side outer packaging material 11B Abdominal side outer packaging material 12 Outer layer sheet 12A Abdominal side outer layer sheet 12B Back Side outer layer sheet 13 Inner layer sheet 15 Body joint part 20A, 20B Girth circumference part 100 Diaper continuous body 110A Ventral outer packaging material continuous body 110B Ventral outer packaging material continuous body 120A, 120B First belt-like sheet 130A, 130B Second belt-like sheet

Claims (4)

In a pants-type disposable diaper that is divided into a ventral part located on the wearer's ventral side and a dorsal part located on the dorsal side when worn, and a waist opening and a pair of leg openings are formed,
An absorbent main body including an absorbent core, and an outer packaging material bonded to the non-skin contact surface side of the absorbent main body,
The outer packaging material includes at least a ventral outer packaging material disposed on the abdominal side portion of the absorbent main body, and a back side outer packaging material disposed on the back side portion of the absorbent main body,
Both side edges of the ventral outer packaging material and the back outer packaging material are joined together to form a pair of side seal parts, a waist opening part and a pair of leg opening parts,
Each of the ventral outer packaging material and the back outer packaging material has a structure in which an outer layer sheet made of a nonwoven fabric and an inner layer sheet are laminated, and at least one of the outer layer sheet and the inner layer sheet is made of an elastic sheet. And
A pants-type disposable diaper in which physical properties of a waistline portion of the abdomen outer packaging material and a waistline portion of the backside packaging material are different.   The underpants-type disposable diaper according to claim 1, wherein an elongation stress in the width direction at the waistline portion of the ventral outer packaging material is smaller than an extension stress in the width direction at the waistline portion of the backside outer packaging material.   The underpants-type disposable diaper according to claim 1 or 2, wherein an air permeability at a waist portion of the back side outer packaging material is higher than an air permeability at a waist portion of the abdominal side outer packaging material.   Both the outer layer sheet of the ventral outer packaging material and the outer layer sheet of the back outer packaging material are made of a stretchable sheet, and the end of the ventral outer packaging material on the center side in the longitudinal direction of the stretchable sheet and the backside packaging material The pants-type disposable diaper according to any one of claims 1 to 3, wherein a distance from the end of the stretchable sheet in the longitudinal direction central side is 0 to 400 mm.

Images