JP2007312951A - Shorts-type disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disposable diaper having an absorbent body and an external capsule material in which the absorbent body is hardly removed from the external capsule material even though the external capsule extends in a width direction and the softness of the external capsule material to a skin abutting face is excellent. <P>SOLUTION: The disposable diaper has the absorbent body 10 including an absorbable core 4 and the external capsule material 11 connected to the side not abutting to the skin, side seal portions, a waist opening portion and leg opening portions are formed by bonding both the side end portions of the external capsule material 11 each other, the external capsule material 11 has a laminated structure constituted of an outer layer sheet 12 comprising an expandable sheet and an inner sheet comprising a nonexpandable sheet, the outer layer sheet 12 and the inner layer sheet 13 remains unbonded almost in all part excepting respective peripheral fringe portions of the side seal portions, the waist opening portion and the leg opening portion, the adsorbent body 10 and the inner layer sheet 13 of the external capsule material 11 remain bonded by the body bonding portion 15, and the substantial width of the inner sheet 13 is wider than width of the outer layer sheet 12 in a contraction in a condition where the side seal portions are separated and the external capsule material 11 is developed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pants-type disposable diaper and a method for manufacturing the same.

  Conventionally, in a disposable diaper comprising an absorbent main body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body, the object is to improve the fit of the diaper to the wearer Further, a material using an elastic sheet as an outer packaging material is disclosed. In addition, according to such a disposable diaper, since it is not necessary to use a linear elastic body 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 In addition to being excellent, problems such as rubber marks when worn by a linear elastic body can be solved.

However, in the disposable diaper having such a configuration, even if the outer packaging material has elasticity, the absorbent main body does not substantially have elasticity, so that the elasticity of the outer packaging material is inhibited. For this reason, problems such as difficulty in wearing a diaper and a lack of fit when worn are likely to occur.
Then, the proposal which makes the joining area of an absorptive main body and an outer packaging material small is made (for example, refer the following patent document 1).

Japanese Patent Laid-Open No. Sho 62-162001

  In the disposable diaper described in Patent Document 1, the above-mentioned problem is improved to some extent by reducing the joint area between the absorbent main body and the outer packaging material, but the joint surface of the outer packaging material with the absorbent main body expands and contracts. Therefore, when the outer packaging material extends in the width direction during use, problems such as peeling of the absorbent main body from the outer packaging material and tearing of the outer packaging material still occur. In addition, further improvement in the softness of the skin contact surface of the outer packaging material is desired.

  Accordingly, an object of the present invention is to provide a disposable diaper including an absorbent main body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body. It is an object of the present invention to provide a pants-type disposable diaper that is unlikely to cause a problem such as peeling of the absorbent main body from the outer packaging material even when stretched, and that is excellent in the softness of the skin contact surface of the outer packaging material.

  The present invention comprises an absorbent main body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body, and both side edges of the ventral side portion and the back side portion of the outer packaging material. A pants-type disposable diaper in which a pair of side seal parts, a waist opening part, and a pair of leg opening parts are formed, the outer packaging material being an outer layer sheet made of an elastic sheet and a non-elasticity The outer layer sheet and the inner layer sheet have a structure in which an inner layer sheet made of a sheet is laminated, and the outer layer sheet and the inner layer sheet are all or a large area of a portion excluding the side seal portion, the waist opening portion, and the leg opening portion. The absorbent main body and the inner layer sheet of the outer packaging material are joined by a main body joining portion, the side seal portion is separated, and the outer packaging material is unfolded. Te, substantial width of the inner layer sheet is obtained by achieving the above object by providing a shorts type disposable diaper is wider than the width of the outer layer sheet contracted state.

  Further, the present invention is a method for producing the pants-type disposable diaper, wherein the outer layer sheet in a state of extending in the width direction is joined to the inner layer sheet in a state of being expanded in the width direction, and the extended state of the outer layer sheet A pants-type disposable diaper in which the absorbent main body is joined to the inner layer sheet by the main body joining portion while maintaining the condition, and then the extension force to the outer layer sheet is released and the outer layer sheet is contracted by the contraction force. A manufacturing method is provided.

According to the present invention, it is possible to achieve a pants-type disposable diaper having excellent appearance, good fit at the time of wearing, easy to wear, and free from problems such as peeling of the absorber during use and tearing of the outer packaging material. Become.
Moreover, according to the manufacturing method of the underpants type disposable diaper of this invention, the said underpants type disposable diaper can be manufactured efficiently.

Hereinafter, the underpants type disposable diaper of this invention is demonstrated, referring drawings based on the preferable one Embodiment.
The disposable diaper 1 of the present embodiment is disposed between a liquid-permeable top sheet 2, a liquid-impermeable or water-repellent back sheet 3, and both sheets 2, 3, as shown in FIGS. A substantially vertically long absorbent main body 10 having a liquid-retaining absorbent core 4 and an outer packaging material 11 joined to the back sheet 3 side (non-skin contact surface side) of the absorbent main body 10 are provided. .

  The outer packaging material 11 has an hourglass shape in which both side edges are bound inwardly in the central portion in the longitudinal direction, and defines the outline of the diaper. The outer packaging material 11 is divided in the longitudinal direction into an abdominal side A disposed on the wearer's abdomen, a back side B disposed on the dorsal side, and a crotch C positioned therebetween. The abdomen A and the back B correspond to the longitudinal front and rear ends of the outer packaging material 11, and the crotch C corresponds to the longitudinal center of the outer packaging material 11. The outer packaging material 11 has both side edges A1, A2 of the ventral side A and both side edges B1, B2 of the back side B joined together, and the disposable diaper 1 has a waist opening 5 and a pair of leg openings. 6 is 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.

  The top sheet 2, the back sheet 3 and the absorbent core 4 are each rectangular, 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 is coat | covered with the tissue paper (not shown) can be used.

  As shown in FIG. 5, the absorbent core 4 in the present embodiment includes an hourglass-shaped central absorbent body 41 and a pair of side absorbent bodies 42, 42 provided symmetrically on both sides of the central absorbent body 41. is doing. The central absorbent body 41 and the pair of side absorbent bodies 42 are separated from each other at least at the crotch portion. One side in the longitudinal direction and the other part in the longitudinal direction of the side absorbent body 42 are connected to each other at one longitudinal part (abdominal side) and the other longitudinal part (back side) of the central absorbent body 41, respectively. Therefore, between the central absorbent body 41 and the pair of side absorbent bodies 42 and 42, cut-out portions 43 and 43 having a shape that is punched are formed.

In addition, a longitudinal direction one part, a longitudinal direction center part, and a longitudinal direction other part are each area | region when dividing the absorptive core 4 into 3 area | regions so that it may divide into about 3 equally in a longitudinal direction.
When the absorptive core 4 has the separation part 43, the both-sides edge part of the absorptive core 4 will stand up easily. Moreover, since the width | variety of the absorptive core 4 whole will become narrow if the absorptive core 4 is pressed in the width direction, the shrinkage | contraction of the width direction of the outer packaging material 11 is hard to be inhibited.

  The shape of the absorbent core 4 in plan view is not limited to the shape shown in FIG. 5. For example, the side absorbent body 42 is connected to the central absorbent body 41 only in one of the longitudinal direction one part or the longitudinal direction other part. The shape in which the side absorber 42 is not connected (separated) to the central absorber 41, or the shape that does not have the separation portion 43 may be used (not shown).

  As shown in FIGS. 2 to 4, side cuffs 8 and 8 made of a liquid-resistant or water-repellent and breathable material are formed on the left and right sides of the absorbent main body 10 in the longitudinal direction. . In the vicinity of the free end of each side cuff 8, a side cuff elastic member 81 is arranged in an extended state. Accordingly, when the disposable diaper 1 assembled as shown in FIG. 1 is worn, the side cuff 8 is erected by contraction of the side cuff elastic member 81, and the liquid in the width direction of the absorbent main body 10 is raised. Is prevented from flowing out. 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 outside the width direction of the absorbent main body 10 in the diaper state. It is wound down to the skin contact surface side and is fixed between the absorbent core 4 and the back sheet 3.

  The outer packaging material 11 has a structure in which an outer layer sheet 12 made of a stretchable sheet and an inner layer sheet 13 made of a non-stretchable sheet are laminated. The outer layer sheet 12 forms the outer surface of the diaper, and 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.

  “Stretchability” in the stretchable sheet refers to an extensible sheet (a sheet having a length that is doubled or longer) having a maximum elongation in at least one direction of 100% or more, and a maximum elongation of 100% or more. It means that the elongation recovery rate (elongation recovery rate at 100% elongation) when stretched in the direction to 100% elongation 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).

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

  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. An elastic sheet made of elastic fibers (elastomer) having a stretchable layer on the non-skin contact surface side is generally not preferable from the viewpoint of texture because it gives a slimy feeling when touched.

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 Preferably, a sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic sheet, and (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of the elastic film are preferably used. Can do.
In addition, as a method of integrating the elastic fiber layer and the extensible fiber layer, for example, a method of laminating them and hydroentangling, or a method of entangling fibers by air through, heat embossing, adhesive, ultrasonic The method of joining by etc. is 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.

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 resulting laminated sheet having a three-layer structure is subjected to hot air treatment using 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 is also omissible.

  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, polyester, and the like. 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.

Next, the non-stretchable sheet forming the inner layer sheet 13 will be described.
The non-stretch 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 100% elongation.
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.

  Furthermore, since the outer layer sheet 12 generally has low sheet strength, the outer packaging material 11 may be torn during use, or the outer packaging material 11 may be accidentally pierced by a finger when wearing a diaper. 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]
A sample having a length of 50 mm and a width of 25 mm is prepared, the sample is set with a chuck distance of 30 mm, and a tensile test is performed at a test speed of 300 mm / min. The same measurement is performed 5 times, and the average value of the maximum point loads obtained at that time is defined as the breaking strength in the diaper width direction and the diaper length direction.
From the viewpoint of breaking strength and air permeability, the inner layer sheet 13 is preferably a nonwoven fabric obtained from a production method such as spunbond or heat roll.

  In the disposable diaper 1 of this embodiment, as shown in FIG.3 and FIG.4, between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in each of the ventral | abdominal side part A and the back | dorsal side part B, it is side seal part A1, A2. , B1 and B2 are bonded 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 adhesive. They are joined together by adhesives 52 and 62 such as agents. And between the outer layer sheet | seat 12 and the inner layer sheet | seat 13 in each of the ventral | abdominal side part A and the back | dorsal side part B is not joined in most parts except these parts.

  Specifically, between the outer layer sheet 12 and the inner layer sheet 13, the side seal portions A 1, A 2, B 1, B 2, the peripheral edge portion 50 of the waist opening 5, and the peripheral edge portions 60 of each of the pair of leg openings 6. And it is joined in the diaper width direction center part of each of the abdominal part A and the back part B, and it is not joined in parts other than those.

  In this way, in a wide range in the ventral side A and the back side B, the outer layer sheet 12 and the inner layer sheet 13 are not joined to each other, thereby minimizing the portion where the outer packaging material 11 is hardened by the adhesive. The portion of the outer surface of the diaper or the inner surface of the outer packaging material 11 that is not covered with the absorbent main body 10 can be made soft and soft to the touch. In addition, when breathable sheets are used as the outer layer sheet 12 and the inner layer sheet 13, the breathability is maintained well, so that a diaper that is less likely to be swollen can be provided. Furthermore, since the outer peripheral sheet 12 and the inner layer sheet 13 are joined to each other at the peripheral edge portions 50 and 60 of the waist opening 5 and the pair of leg openings 6, the stretchable outer packaging material 11 is provided at the waistline portion. Therefore, moderate fit can be obtained.

  A plurality of waist elastic members 51, 51 are disposed along the peripheral edge of the waist opening 5 at the peripheral edge 50 of the waist opening 5 in each of the ventral side A and the back side B. These waist elastic members 51, 51 are fixed in an extended state between the outer layer sheet 12 and the inner layer sheet 13 via an adhesive 52.

In addition, leg elastic members 61a and 61b are also provided along the peripheral edge of each opening on the peripheral edge 60 and 60 of the leg opening that exists across the ventral side A, crotch C and back side B. It is 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.

  In this way, thread-like or belt-like elastic members 51, 61a, 61b are sandwiched between the outer layer sheet 12 and the inner layer sheet 13 at the peripheral edge portions 50, 60 of the waist opening 5 and the pair of leg openings 6, respectively. By fixing to the state, the fit of these parts can be enhanced without being restricted by the expansion and contraction characteristics of the outer packaging material 11.

  In addition, since the thread-like or belt-like elastic members 51, 61a, 61b can be fixed between the outer layer sheet 12 and the inner layer sheet 13, such elastic members are fixed to the outer packaging material made of a single sheet. Compared to the case, the elastic member can also prevent the wearer from feeling uncomfortable or deteriorating the appearance.

In the disposable diaper 1 of the present embodiment, the width of the region where the outer layer sheet 12 and the inner layer sheet 13 are present at the peripheral edge 50 of the waist opening 5 is about the ventral side A and the back side B, respectively. It is preferably within 70 mm from the peripheral edge 5a, 5b of the waist opening, and more preferably within 60 mm.
The width of the region where the outer layer sheet 12 and the inner layer sheet 13 are joined to each other at the peripheral edge 60 of the leg opening 6 is the leg opening at each of the ventral side A, the crotch C and the back side B. 6 is preferably within 50 mm, more preferably within 30 mm from the peripheral edge.

  Moreover, in the diaper width direction in each of the ventral side part A and the back side part B, the total length (L1 + L2) of the portion where the outer layer sheet 12 and the inner layer sheet 13 are not joined is determined by the left and right side seal parts A1, The length La (Lb) between A2 is preferably 60% or more, more preferably 70% or more, and further preferably 75% or more.

  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 side A and the back side B is relative to the respective areas of the outer layer sheet 12 in the ventral side A and the back side B. 60 to 100% is preferable, and 70 to 100% is more preferable. Those satisfying this numerical value are referred to as “whole area or most part”.

  As shown in FIG. 2, the dimensions and ratios of the respective parts described in this specification are in a natural state (external force such as tension is applied) with the diaper in an unfolded state and the contraction force by the elastic members of the waist opening and the leg opening is released. The value measured in the state of not acting) or based on it.

  In the disposable diaper 1 of the present embodiment, the adhesive 62 is bonded between the outer layer sheet 12 and the inner layer sheet 13 in the crotch part C at the peripheral edge part 60 of the leg opening and the diaper width direction central part of the crotch part C. Although it is joined via the part 14, it is not joined in other parts. In the disposable diaper 1 of the present embodiment, as shown in FIG. 2, the leg elastic member 61 for imparting stretchability to the peripheral edge 60 of the leg opening is formed from the peripheral edge 60 of the leg opening to the crotch C The leg portion elastic member 61 for imparting stretchability to the leg opening in the circumferential direction is thus arranged at the periphery of the leg opening. 60.

  In the disposable diaper 1 of this embodiment, since the outer layer sheet 12 and the inner layer sheet 13 are joined at the central part in the diaper width direction of each of the abdominal part A, the back side part B, and the crotch part C, the diaper The appearance before and during mounting can be further improved. Further, when a disposal tape (not shown) is provided on the outer surface of the outer packaging material 11, the disposal tape can be firmly fixed by fixing the disposal tape to the central part in the diaper width direction. The disposal tape is a tape that holds the diaper in a rolled state, and various conventionally known tapes can be used.

  Since the outer layer sheet 12 and the inner layer sheet 13 are joined in the diaper width direction center of each of the ventral side A, the back side B, and the crotch part C, the back sheet 3 has patterns, characters, and other symbols. When such a design is provided, the design can be clearly seen from the outer surface side of the diaper.

  In the disposable diaper 1 of this embodiment, as shown in FIG.2 and FIG.3, the outer-layer sheet | seat 12 which comprises the outer surface side of the outer packaging material 11 is each waist part elastic member 51 by the outer-layer sheet | seat 12 and the inner-layer sheet | seat 13. , 51 has a length that extends further than the portion that clamps and fixes 51, 51, and the portions 12 a and 12 b that extend from the inner layer sheet 13 in the outer layer sheet 12 are folded back to the absorbent main body 10 side.

  As for the absorptive main body 10, the skin contact surface side in the longitudinal direction both ends is covered with the folded-back portions (folded portions) 12a and 12b of the outer layer sheet 12. The folded portions 12a and 12b of the outer layer sheet 12 are bonded to the ends of the absorbent main body 10 in the longitudinal direction via an adhesive (not shown) over substantially the entire width of the absorbent main body 10, Thereby, the longitudinal direction both ends of the absorptive main body 10 are fixed to the outer packaging material 11.

  By forming the folded portions 12a and 12b, the front and rear end portions of the absorbent main body 10 are prevented from coming into direct contact with the wearer, and the water absorbent polymer of the absorbent core 4 from the front and rear end portions of the absorbent main body 10 is prevented. Leakage can be prevented.

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 joined to the inner-layer sheet | seat 13 of the outer packaging material 11 by the main body junction part 15. FIG. .
From the viewpoint of preventing peeling of the absorbent main body 10 from the outer packaging material 11, the total area T <b> 2 of the main body joint portion 15 with respect to the area T <b> 1 of the surface facing the outer packaging material 11 in the absorbent main body 10 in the contracted state of the outer packaging material 11. The ratio T2 / T1 is preferably 60% or more, and more preferably 65% or more.
The width W1 of the joint portion 14 between the outer layer sheet 12 and the inner layer sheet 13 in the central portion of the outer packaging material 11 in the diaper width direction is equal to the width W of the absorbent main body 10 in each of the ventral portion A and the back portion B. It is preferably 0 to 40%, and more preferably 0 to 30%. When the width W1 of the joint portion 14 exceeds 40% of the width W of the absorbent main body 10, the stretchability is inhibited.

  The main body bonding portion 15 is in the form of a band extending in the longitudinal direction, and one main body bonding portion 15 is provided at the central portion in the diaper width direction. The width W2 of the main body joint portion 15 is preferably 70% or more of the width W on the non-skin contact surface side of the absorbent main body 10 in each of the abdominal side A and the back side B, and is 75% or more. More preferably. 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 present invention, in the state where the side seal portion S is separated and the outer packaging material 11 is deployed, the substantial width of the inner layer sheet 13 is wider than the width of the outer layer sheet 12 in a contracted state. That is, in the state in which the outer packaging material 11 is deployed, the outer layer sheet 12 is in a contracted state due to its contraction force, but the inner layer sheet 13 is made of a non-stretchable sheet, so that the width is hardly reduced. Therefore, the inner layer sheet 13 is loosened in the width direction with respect to the outer layer sheet 12. Such a slackened inner layer sheet 13 is virtually separated from the outer layer sheet 12, and the width of the inner layer sheet 13 when the slackness of the inner layer sheet 13 is eliminated is defined as “substantial width of the inner layer sheet 13”.

  The substantial width of the inner layer sheet 13 is preferably 1.3 to 4.0 times, more preferably 1.5 to 3.0 times the width of the outer layer sheet 12 in a contracted state. The outer packaging material 11 having such a configuration can be manufactured by, for example, a manufacturing method described later.

  In the pants-type disposable diaper 1 of the present embodiment configured as described above, in the state where the side seal portion S is separated and the outer packaging material 11 is deployed, the substantial width of the inner layer sheet 13 is in a contracted state. It is wider than the width of the outer layer sheet 12. Therefore, since the outer layer sheet 12 of the outer packaging material 11 is formed from an elastic sheet, the appearance and fit of the diaper when worn is good. Further, since the inner layer sheet 13 of the outer packaging material 11 is formed from a non-stretchable sheet, even when the outer packaging material 11 extends in the width direction at the time of use, the inner layer sheet 13 is loosened, and the absorbent main body 10 from the outer packaging material 11 Problems such as peeling off and tearing of the outer packaging material 11 hardly occur. Moreover, the skin contact surface side of the outer packaging material 11 has good tactile sensation and texture, and is excellent in softness.

  Since the outer layer sheet 12 made of a stretchable sheet and the inner layer sheet 13 made of a non-stretchable sheet are hardly adhered, the stretchability of the outer packaging material 11 is good without being affected by the non-stretchable absorbent main body 10. It is. Even when the outer layer sheet 12 of the outer packaging material 11 is released from the stretched state, the absorbent main body 10 is excellent in appearance without contracting, and the absorbent performance of the absorbent main body 10 can be maintained. Therefore, even if the width W2 of the main body joint portion 15 is set wide, the stretchability in the width direction of the outer packaging material 11 is not hindered.

Next, the manufacturing method of the underpants type disposable diaper of this invention is demonstrated based on the preferable one embodiment. The manufacturing method of this embodiment is a method of continuously producing the pants-type disposable diaper 1 of the above embodiment.
In the manufacturing method of this embodiment, as shown in FIG. 6, the outer layer sheet 12 expanded in the width direction is joined to the inner layer sheet 13 expanded in the width direction, and the expanded state of the outer layer sheet 12 is maintained. A pants-type disposable diaper in which the absorbent main body 10 is joined to the inner layer sheet 13 by a main body joint (not shown), and then the extension force to the outer layer sheet 12 is released and the outer layer sheet 12 is contracted by the contraction force. It is a manufacturing method.

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

  As the first belt-like sheet 120, a sheet produced as a belt-like sheet having stretchability in the longitudinal direction in advance in the longitudinal direction outside the diaper production line can be used, but in this embodiment, as shown in FIG. Prior to the step of extending the first belt-like sheet 120 in the longitudinal direction, the non-stretchable belt-like sheet 120 ′ is processed to obtain the first belt-like sheet 120 exhibiting stretchability or the low-stretchable belt-like sheet 120. The process includes a step of obtaining a first belt-like sheet 120 having improved stretchability by being processed, and the first belt-like sheet 120 thus obtained is elongated.

  In the present embodiment, 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 the teeth and the grooves are engaged, as shown in FIG. More specifically, a belt-like sheet 120 ′ in which an inelastic fiber layer is integrated on both sides or one side of an elastic layer made of an elastic fiber layer, a net-like elastic sheet, an elastic film, etc. 71, so that the non-elastic fiber layer is divided, the constituent fibers are stretched, the heat-sealing points between the fibers are broken, and the elastic layer is not easily inhibited from stretching and contracting. Yes. 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 sheet 120 in which the stretchability is expressed or improved is obtained.

  As described above, before the step of extending the first belt-like sheet 120 in the longitudinal direction, the non-stretchable or low-stretchy belt-like sheet 120 ′ is processed inline to develop stretchability or enhance stretchability. By providing a process, the stretchability equivalent to the sheet | seat manufactured beforehand as a strip | belt-shaped sheet | seat which has a stretching property in a longitudinal direction outside the manufacturing line of a diaper can be obtained. The width of the non-stretchable or low-stretchable belt-like sheet 120 ′ is preferably 100 to 180% of the width of the first belt-like sheet 120 in consideration of shrinkage of the width when processed in-line. More preferably, it is 160%.

  In this embodiment, the first belt-like sheet 120 obtained as described above is stretched between the first nip roll 72 and the second nip roll 73 while being continuously conveyed. The first nip roll 72 and the second nip roll 73 are each composed of a pair of rolls, and the rotational speeds (peripheral speed, rotational speed) of the pair of rolls constituting the second nip roll 73 rather than the pair of rolls constituting the first nip roll 72. It is driven so that the sheet feeding speed is increased. The pair of turning rolls 75a and 75a turn the first belt-like sheet 120 extended so as to join the second belt-like sheet 130.

  Next, the first belt-like sheet 120 (outer layer sheet 12) stretched in the width direction is bonded to and bonded to the second belt-like sheet 130 (inner layer sheet 13) developed in the width direction. Since the second belt-like sheet 130 is a non-stretchable sheet and the first belt-like sheet 120 is a stretchable sheet, the second belt-like sheet 130 that is substantially in an unstretched state and a state in which the shrinkage in the width direction is expressed. The 1st strip | belt-shaped sheet | seat 120 will be bonded together.

  In this embodiment, the first belt-like sheet 120 and the second belt-like sheet 130 are bonded to each other between the belt-like sheets 120 and 130 as shown in FIG. This is performed in a state where the member 51 is sandwiched. Specifically, before the two belt-like sheets 120 and 130 are overlapped, the adhesive 52 and 62 for fixing the elastic member is attached to a predetermined part of one or both of the two belt-like sheets 120 and 130 facing each other. In a state where the elastic members 61a, 61b, 51 are sandwiched in an expanded state, the two belt-like sheets 120, 130 are narrowed by a pair of nip rolls 74, 74, and the elastic members 61a, 61b, 51 are The belt-like sheets 120 and 130 are joined together while being fixed.

The leg elastic members 61a and 61b are introduced between the belt-like sheets 120 and 130 while being swung by a known rocking guide in a direction orthogonal to the flow direction of the belt-like sheets 120 and 130. The pair of turning rolls 75b and 75b turns the conveying direction of the belt-like sheet 130 in a predetermined direction.
By bonding the first belt-like sheet 120 and the second belt-like sheet 130, the outer packaging material continuous body 110 in which the extent of extension in the longitudinal direction is limited is obtained.
The pair of turning rolls 75c and 75c turns the conveying direction of the outer packaging material continuous body 110 in a predetermined direction.

In the present embodiment, the first belt-like sheet 120 is bonded to the second belt-like sheet 130 in a state where the first belt-like sheet 120 is elongated in the longitudinal direction, and the first belt-like sheet 120 is in a state where the width is reduced by the elongation ( It is joined to the second belt-like sheet 130 in a so-called reduced width state. Therefore, the first belt-like sheet 120 used as the raw sheet of the outer layer sheet 12 takes into account the width shrinkage due to the elongation, and the width before being elongated in the longitudinal direction (the same as the width in the non-stretched state) is the same as that of the second belt-like sheet 130. Use of a sheet having a width of 100 to 140% of the width of the first belt-like sheet 120 after joining is such that the width of the first belt-like sheet 120 in the state of being elongated in the longitudinal direction due to the width reduction due to the elongation is the second belt-like sheet. It is preferable from a viewpoint not to become smaller than the width of 130, and it is more preferable to use 110 to 130%.
The elongation ratio of the first belt-like sheet 120 when bonded to the second belt-like sheet 130 is, for example, 1.3 to 4.0 times, and more preferably 1.5 to 3.0 times.

The pants-type disposable diaper 1 of the above embodiment can be manufactured in the same manner as a conventional so-called cross-flow type pants-type disposable diaper, except that the outer packaging material continuum 110 obtained as described above is used. it can.
For example, as shown in FIG. 6, the absorbent main body 10 obtained by cutting the absorbent main body continuous body 101 on the outer packaging material continuous body 110 is rotated 90 degrees with respect to the flow direction, and then intermittently. Adhere to and fix. Further, the diaper continuous body 100 is obtained by removing the trim 111 for forming the leg opening by a rotary cutter, a laser cutter or the like.

  The absorptive main body 10 is fixed to the outer packaging material continuous body 110 while maintaining the stretched state of the first belt-like sheet 120. In other words, the absorbent main body 10 is fixed while maintaining the outer wrapping material continuous body 110 so as not to shrink due to the contraction force of the first belt-like sheet 120. Next, both side portions 12a and 12b of the outer packaging material continuous body 110 in the diaper continuous body 100 are folded back so as to cover both end portions of the absorbent main body 10, and both side portions of the outer packaging material continuous body 110 are formed at both end portions of the absorbent main body 10. After fixing 12a and 12b, 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.

  As a method of intermittently fixing the absorbent main body 10 by 90 degrees and intermittently fixing it on the outer packaging material continuous body 110, for example, a method described in JP-A-4-166150 can be used. Further, a main body joint (not shown) for fixing the absorbent main body 10 to the outer packaging material continuous body 110 can be applied to either one or both of the absorbent main body 10 and the outer packaging material continuous body 110. . Further, the removal of the trim 111 for forming the leg opening can be performed before the absorbent main body 10 is fixed to the outer packaging material continuous body 110.

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

  That is, even if the first belt-like sheet 120 is a sheet having excellent stretchability in the longitudinal direction, the outer packaging material continuous obtained by pasting it with the second belt-like sheet 130 that does not substantially stretch in the stretched state. The body 110 is hardly stretched any more, or is slightly stretched when it is slightly stretched (so-called stretched growth). Therefore, if the outer packaging material continuum 110 is transported with a certain level of tension, even if the tension applied to the outer wrapping material continuum 110 fluctuates during transportation, the elongation amount (elongation rate) of the outer packaging material continuum 110 is Fluctuation hardly occurs.

  Therefore, for example, a bonding position when the absorbent main body 10 is bonded to the outer packaging material continuous body 110, or a formation position when the leg hole 112 is formed in the outer packaging material continuous body 110 before and after fixing the absorbent main body 10 The folding position when the outer packaging material continuous body 110 (diaper continuous body 100) to which the absorbent main body 10 is fixed is folded in two, and the predetermined location of the outer packaging material continuous body 110 (diaper continuous body 100) to which the absorbent main body 10 is fixed. It is possible to prevent a shift in the sealing position when forming the side seal S by sealing and the cutting position when the diaper continuous body 100 is cut and divided into individual diapers, and stable pant-type disposable diapers with high finishing accuracy. Can be manufactured.

  In addition, by partially joining the first belt-like sheet 120 and the second belt-like sheet 130, the stretchability of the outer packaging material continuous body 110 derived from the stretchability of the first belt-like sheet 120 is not impaired by the adhesive. Since the degree is small even if damaged, the obtained disposable diaper 1 has good outer packaging material 11 in the diaper width direction (left-right direction in FIG. 2) due to the stretchability of the first belt-like sheet 120. It expands and contracts, shows a good fit to the wearer's waist, and is excellent in wearing feeling and leakage prevention.

In the embodiment shown in FIG. 6, the first belt-like sheet 120, which is the original fabric of the outer layer sheet 12, is stretched in the longitudinal direction thereof, and then the second fabric which is the original fabric of the inner layer sheet 13 while being elongated. Although it is joined to the belt-like sheet 130, in the manufacturing method of the present invention, the first belt-like sheet 120 is stretched in the width direction and is cut intermittently, and then sequentially generated by the intermittent cutting. After the short object is rotated 90 degrees and then connected to form a long sheet having stretchability in the longitudinal direction (flow direction), it can be joined to the second belt-like sheet 130.
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 an embodiment, the first strip sheet is stretched between the first nip roll 72 and the second nip roll 73, and in this state, the first strip sheet is bonded and bonded to the second strip sheet 130. And by using the outer packaging material continuum 110 thus obtained, a pants-type disposable diaper can be stably and continuously produced as in the embodiment shown in FIG.

As mentioned above, although this invention was demonstrated based on the preferable embodiment or embodiment, this invention is not restrict | limited to the said embodiment or embodiment.
The coating shape of the joint portion 14 for joining the outer layer sheet 12 and the inner layer sheet 13 to the side seal portion S and the portions other than the peripheral edge portions 50 and 60 of the waist opening portion 5 and the leg opening portion 6 is the same as that in the above embodiment. It is not limited to the coating shape (coating shape over the entire longitudinal direction at the center in the width direction).

For example, the coating shape of the joint portion 14 may be a discontinuous (intermittent) coating shape in the width direction. As such a coating shape, as shown to Fig.7 (a), the coating shape in which the several strip-shaped junction part 14 extended in a longitudinal direction was arranged at predetermined intervals in the width direction is mentioned.
Moreover, the coating shape of the junction 14 may be a discontinuous (intermittent) coating shape in the longitudinal direction. As such a coating shape, as shown in FIG. 7B, there is a coating shape in which a plurality of strip-shaped joint portions 14 extending in the width direction are arranged at predetermined intervals in the longitudinal direction. The band-shaped joint portion 14 extending in the width direction can be provided only in the central portion in the longitudinal direction or only at both ends in the longitudinal direction.
The joint 14 may not be provided.

  As shown in FIG. 8A, the coating shape of the joint portion 14 may be a spiral coating shape, or may be a coating shape (not shown) other than a belt shape. In the joint portion 14 having a coating shape other than the strip shape, as shown in FIG. 8B, the area of the strip region when the minimum stripable region including the joint portion 14 is virtually formed. Is the bonding area of the bonding portion. Even in the joint portion 14 having a coating shape other than the belt shape, 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 side portion A and the back side portion B is as follows. 60 to 100% is preferable and 70 to 100% is more preferable with respect to each area of the outer layer sheet 12 of the side portion B.

The coating shape of the main body joint portion 15 is not limited to the coating shape in the embodiment. FIGS. 9A and 9B are bottom views of another coating shape of the main body joint portion 15 as viewed from the side facing the outer packaging material 11 in the absorbent main body 10. As shown in FIG. 9A, the coating shape of the main body bonding portion 15 is one strip-shaped coating that extends in the longitudinal direction and is disposed at the center in the diaper width direction, and the longitudinal front and rear ends of the absorbent main body 10. It can be set as the shape which consists of an aggregate | assembly with the two strip | belt-shaped coatings extended in the width direction each arranged by the part. That is, the coating shape of the main body joint 15 shown in FIG. 9A is similar to the capital letter “I” of the alphabet.
Further, the coating shape of the main body joint portion 15 may be a shape separated in the diaper width direction, for example, an aggregate of two strip-shaped coatings extending in parallel in the longitudinal direction as shown in FIG. 9B. It can be set as the shape which consists of.

As shown in FIG. 10A, the coating shape of the main body joint portion 15 may be a spiral coating shape, or may be another coating shape (not shown) other than a belt shape. In the main body joint portion 15 having a coating shape other than the belt shape, as shown in FIG. 10B, the belt-like region when the belt-shaped region having the minimum area that can include the main body joint portion 15 is virtually formed. Is the bonding area of the main body bonding portion. Also in the main body joint 15 having a coating shape other than the belt shape, the ratio T2 / T1 of the total area T2 of the main body joint 15 to the area T1 of the absorbent main body 10 facing the outer packaging material 11 is 60% or more. Is more preferable and 65% or more is more preferable.
The joining by the joining part 14 between the outer layer sheet 12 and the inner layer sheet 13 and the joining by the body joining part 15 between the absorbent main body 10 and the outer packaging material 11 are not limited to joining using an adhesive, but are general joining by heat. (Embossing, ultrasonic sealing, etc.) can also be achieved.

The joining or engaging position of the side edges A1, A2 of the ventral side A and the side edges B1, B2 of the back side B is not limited to the position directly beside the body, but at a position slightly forward or rearward of the body. There may be.
Further, on the non-skin contact surface side (outer layer sheet 12 side) of the outer packaging material 11 of the disposable diaper 1 described above, the disposable tape is fixed by fixing the disposal tape at a position overlapping the joining portion 14 such as a hot melt adhesive. It can also be set as the disposable diaper 1 which can be discarded compactly, maintaining the elasticity of the diaper 1.

FIG. 1 is a perspective view showing an embodiment of a pants-type disposable diaper of the present invention. FIG. 2 is a plan view showing a developed state of the disposable diaper shown in FIG. 1. FIG. 3 is an exploded perspective view of the disposable diaper shown in FIG. 1. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a plan view showing an absorbent core in the disposable diaper shown in FIG. 1. FIG. 6 is a perspective view showing an embodiment of a method for producing a pants-type disposable diaper of the present invention. Fig.7 (a) and FIG.7 (b) are typical top views which show the example of the coating shape of the junction part of an outer layer sheet and an inner layer sheet, respectively. FIG. 8A is a schematic plan view showing a spiral-shaped joint between the outer layer sheet and the inner layer sheet, and FIG. 8B is a schematic plan view used for explaining the joint area of the spiral-shaped joint. It is. Fig.9 (a) and FIG.9 (b) are typical bottom views which show the example of the coating shape of the main body junction part of an absorptive main body and an outer packaging material, respectively. FIG. 10A is a schematic bottom view showing a spiral-shaped main body joint between the absorbent main body and the outer packaging material, and FIG. 10B is a schematic diagram used for explaining the joint area of the spiral-shaped main body joint. FIG.

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 12 Outer layer sheet 13 Inner layer sheet 15 Main body joint part 100 Diaper continuous body 110 Outer packaging material continuous body 120 First belt-like sheet 130 Second belt-like sheet

Claims (6)

An absorbent main body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body, and both side edges of the ventral side portion and the back side portion of the outer packaging material are joined to each other. And a pair of side seal parts, a waist opening part and a pair of leg opening part is a pants-type disposable diaper,
The outer packaging material has a structure in which an outer layer sheet made of a stretchable sheet and an inner layer sheet made of a non-stretchable sheet are laminated, and the outer layer sheet and the inner layer sheet have the side seal portion and the waist opening portion. And not joined in the whole area or most of the portion excluding the peripheral edge of each leg opening,
The absorbent main body and the inner layer sheet of the outer packaging material are joined by a main body joining portion,
A pants-type disposable diaper in which the substantial width of the inner layer sheet is wider than the width of the outer layer sheet in a contracted state when the side seal portion is separated and the outer packaging material is deployed.   The pants-type disposable diaper according to claim 1, wherein a substantial width of the inner layer sheet is 1.3 to 4.0 times a width of the outer layer sheet in a contracted state.   The pants-type disposable diaper according to claim 1 or 2, wherein the outer layer sheet and the inner layer sheet are formed of a nonwoven fabric made of thermoplastic fibers.   The pants-type disposable diaper according to any one of claims 1 to 3, wherein the outer layer sheet is made of a laminated sheet, and at least a layer on the non-skin contact surface side is formed of an air-through nonwoven fabric.   The ratio T2 / T1 of the total area T2 of the main body joint portion to the area T1 of the surface of the absorbent main body facing the outer packaging material in the contracted state of the absorbent main body is 60% or more. The pants-type disposable diaper according to any one of the above. It is a manufacturing method of the underpants type disposable diaper of Claim 1,
The outer layer sheet stretched in the width direction is joined to the inner layer sheet expanded in the width direction, and the absorbent main body is attached to the inner layer sheet by the main body joining portion while maintaining the stretched state of the outer layer sheet. The manufacturing method of the underpants type disposable diaper which joins and releases the expansion | extension force to this outer layer sheet | seat after that, and shrink | contracts this outer layer sheet | seat with the contraction force.

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