JP2008136793A - Pants-type disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pants-type disposable diaper capable of reducing the difference in the tightening force of gathers between the gathers in the center and the gathers in the outer side of the under-waistline part. <P>SOLUTION: The disposable diaper comprises an absorbent body 3 and an external wrapping material 2. Elastic members 23 and 24 are disposed and under-waistline gathers and waistline gathers are formed in the under-waistline part D and a waistline part F of the external wrapping material 2. The under-waistline gathers are composed of a composite stretch part on the outer side of the under-waistline part D, and the waistline gathers are composed of the composite stretch part on the outer side of the waistline part F. In the composite stretch parts, sheets 21 and 22 are jointed with intermittent joint parts in the direction of extension/contraction of the composite elastic part and the orthogonally crossing direction. The elastic members 23 and 24 are disposed in the composite stretch parts not to pass over the joint parts and are not fixed to the sheets 21 and 22. A plurality of pleats continuously extending over the elastic members 23 and 24 are formed in the sheets 21 and 22. The plurality of pleats extend from the outer end of the waistline part F to the inner end of the under-waistline part D in the waistline part F and on the outer side of the under-waistline part D. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

Conventionally, in a pants-type 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, improving the fit of the diaper to the wearer For the purpose of the above, there is known one in which a waistline gather is provided in the waistline portion of the abdomen and back sides of the outer packaging material, and a waist gather is provided in the waist portion (see, for example, Patent Document 1 below). In the pants-type disposable diaper described in Patent Document 1, the outer packaging material is formed of an inner layer sheet, an outer layer sheet, and a plurality of elastic members disposed between both sheets, and the waistline gather and the waist gather are respectively the waistline The elastic member is intermittently joined to the inner layer sheet and the outer layer sheet at the waist and the waist.
Moreover, the disposable diaper which has the same structure is also described in the following patent document 2.

JP 2004-89403 A JP 2005-253731 A

However, in the pants-type disposable diapers described in Patent Documents 1 and 2, the waistline gather and the waist gather are formed by joining elastic members to the inner layer sheet and the outer layer sheet with a hot-melt adhesive. Therefore, it is inferior to the breathability and softness of a waist part and a waist part. Further, since the contraction of the elastic member is hindered, it is necessary to increase the amount of the elastic member or use an elastic member having a large contracting force in order to obtain a sufficient contraction force of the waist gathers and the waist gathers. The contraction force is not fully utilized. Furthermore, the cushioning properties in the thickness direction of the waistline gather and the waist gather are also inferior.
And, in the pants-type disposable diaper provided with the absorbent main body and the outer packaging material, the tightening force due to the waistline gathers is reduced by reducing the difference in the tightening force due to the waistline gathers between the widthwise center part and the widthwise outside part of the waistline part. It is desired to solve the problems caused by the non-uniformity between the center portion in the width direction and the outer portion in the width direction of the waistline portion.

  Accordingly, an object of the present invention is to provide 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 the waistline gather and the waist gather at the waistline part and the waist part. The pants-type disposable diaper has excellent breathability and softness of the waistline portion and the waist portion, can fully utilize the contraction force of the elastic members of the waistline gather and the waist gather, and in the thickness direction of the waistline gather and the waist gather An object of the present invention is to provide a pants-type disposable diaper that has excellent cushioning properties and can reduce the difference in tightening force caused by the waistline gathers between the center part in the width direction and the outer side part in the width direction.

  The present invention includes 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 the outer packaging material is provided on the abdomen, crotch, and back side in the longitudinal direction. A pants-type disposable diaper that is divided and has a pair of side seals, a waist opening, and a pair of leg openings formed by joining the side edges of the abdomen and back sides of the outer packaging material. The longitudinal end portion of the absorbent main body recedes inward in the longitudinal direction from the longitudinal end portion of the outer packaging material, and the outer packaging material is disposed between the outer layer sheet, the inner layer sheet, and both sheets. The elastic members are disposed over the entire circumference of the waist part and the waist part of the stomach part and the back part of the outer packaging material. And waist gathers The gather is formed from a composite stretchable part at least in the widthwise outer side of the waistline part, and the waist gather is formed from the composite stretchable part at least in the widthwise outer side part of the waist part. The outer layer sheet and the inner layer sheet are joined to each other by intermittent joints in the stretching direction of the composite stretchable part and the direction perpendicular thereto, and the elastic member is arranged not to pass through the joint part and excluding both ends of the elastic member The outer layer sheet and the inner layer sheet are not fixed to the outer layer sheet and the inner layer sheet, and each of the outer layer sheet and the inner layer sheet is formed by forming a plurality of ridges extending continuously over a plurality of elastic members, The saddle of the book is worn along the longitudinal direction of the outer packaging material at the outer side in the width direction of the waist part and the outer side in the width direction of the waistline part. It is obtained by achieving the above object by providing a shorts type disposable diaper extending across the inner end of the waist portion from the outer end parts.

  According to the pants-type disposable diaper of the present invention, the pants-type disposable diaper includes 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, In a pants-type disposable diaper having a waist gather, the waistline and waist are excellent in breathability and softness, and the contraction force of the elastic members of the waistline gather and the waist gather can be fully utilized. While being excellent in cushioning properties in the thickness direction, it is possible to reduce the difference in tightening force caused by the waistline gathers between the widthwise central portion and the widthwise outside portion of the waistline portion. Therefore, it is possible to solve the problem caused by the fact that the tightening force by the waistline gathers is not uniform between the widthwise center part and the widthwise outer side part of the waistline part.

Hereinafter, the underpants type disposable diaper of this invention is demonstrated, referring drawings based on 1st Embodiment which is the preferable embodiment.
The pants-type disposable diaper 1 of 1st Embodiment is the outer packaging material joined to the non-skin contact surface side of the absorptive main body 3 containing the absorptive core 34 and the absorptive main body 3, as shown in FIGS. 2 and the outer packaging material 2 is divided in the longitudinal direction into an abdominal side A, a crotch C, and a back side B, and both side edges of the abdominal side A and the back side B of the outer packaging material 2 are A pants-type disposable diaper that is joined to form a pair of side seals 11, a waist opening 12, and a pair of leg openings 13.

  The outer packaging material 2 is formed of an outer layer sheet 21, an inner layer sheet 22, and a plurality of elastic members 23, 24, 25, 26 disposed between both sheets 21, 22. The waistline part D and the waist part F in the part A and the back side part B are provided with a waistline gather G1 and a waist gather G2, respectively, by arranging elastic members 23 and 24 over the entire circumference. Yes.

  More specifically, the disposable diaper 1 of the present embodiment includes a liquid-permeable top sheet 32, a liquid-impermeable or water-repellent back sheet 33, and both sheets 32, 33 as shown in FIGS. A substantially vertically long absorbent main body 3 having a liquid-retaining absorbent core 34 disposed therebetween, and an outer packaging material 2 joined to the back sheet 33 side (non-skin contact surface side) of the absorbent main body 3 It has. The absorbent main body 3 is disposed across the ventral side A to the back side B of the outer packaging material 2, but the longitudinal end of the absorbent main body 3 is more than the longitudinal end of the outer packaging 2. Retreats inward in the longitudinal direction. The absorptive main body 3 is joined to the inner layer sheet 22 of the outer packaging material 2 by a main body joining portion 15 such as an adhesive, a heat seal, and an ultrasonic seal.

  The outer wrapping material 2 has an hourglass shape in which both side edges are bound inward in the central portion in the longitudinal direction, and defines the outline of the diaper. The outer packaging material 2 is divided in the longitudinal direction into an abdominal side A disposed on the abdomen side of the wearer, a back side B disposed on the back side, and a crotch C positioned therebetween. The ventral side A and the back side B correspond to the longitudinal front and rear portions of the outer packaging material 2, respectively, and the crotch portion C corresponds to the longitudinal central portion of the outer packaging material 2. As for the outer packaging material 2, the both-sides edge part of the ventral | abdominal side part A and the both-sides edge part of the back side part B are mutually joined, and the waist opening part 12 and a pair of leg opening part 13 are formed in the disposable diaper 1. . By this joining, a pair of side seal parts 11 and 11 are formed on the left and right side edges of the disposable diaper 1 to form a pant-type. For this joining, heat sealing, high frequency sealing, ultrasonic sealing or the like is used.

  The top sheet 32, the back sheet 33, and the absorbent core 34 are each rectangular, and are integrated to form the vertically long absorbent main body 3. As the surface sheet 32, the back surface sheet 33, and the absorptive core 34, the thing similar to what was conventionally used for this kind of diaper can be used, respectively. For example, the absorbent core 34 may be made of absorbent polymer particles and a fiber material and covered with tissue paper (not shown).

  As shown in FIG. 5, the absorbent core 34 in the present embodiment includes an hourglass-shaped central absorbent body 34 </ b> A and a pair of side absorbent bodies 34 </ b> B and 34 </ b> B provided symmetrically on both sides of the central absorbent body 34 </ b> A. It has. The central absorbent body 34A and the pair of side absorbent bodies 34B and 34B are separated from each other at least in the center in the longitudinal direction. One side in the longitudinal direction and the other side in the longitudinal direction of the side absorbent body 34B are connected to each other at one side in the longitudinal direction and the other side in the longitudinal direction of the central absorbent body 34A, respectively. Therefore, the cut-out portions 34C and 34C are formed between the central absorbent body 34A and the pair of side absorbent bodies 34B and 34B, respectively.

The one part in the longitudinal direction, the central part in the longitudinal direction, and the other part in the longitudinal direction are each region when the absorbent core 34 is divided into three regions so as to be divided into approximately three equal parts in the longitudinal direction.
When the absorbent core 34 has the separation portion 34 </ b> C, both side edges of the absorbent core 34 easily stand up. Further, when the absorbent core 34 is pressed in the width direction, the entire width of the absorbent core 34 is narrowed, so that the shrinkage in the width direction of the outer packaging material 2 is difficult to be inhibited.

  The shape of the absorbent core 34 in plan view is not limited to the shape shown in FIG. 5. For example, the side absorbent body 34 </ b> B is connected to the central absorbent body 34 </ b> A only in one of the longitudinal direction one part or the longitudinal direction other part. May be a shape in which the side absorber 34B is not connected (separated) to the central absorber 34A, or a shape that does not have the separation portion 34C (none of which is shown).

  As shown in FIGS. 2 to 4, side cuffs 35 and 35 made of a liquid-resistant or water-repellent and breathable material are provided on both sides in the longitudinal direction of the absorbent main body 3. In the vicinity of the free end of each side cuff 35, a side cuff elastic member 36 is disposed in an expanded state. Accordingly, when the disposable diaper 1 is worn, the side cuff elastic member 36 contracts, whereby the side cuff 35 stands up, and the outflow of the liquid in the width direction of the absorbent main body 3 is prevented. As shown in FIGS. 3 and 4, the side cuff forming sheet 37 for forming the side cuff 35 has a back surface sheet 33 with a portion 37 </ b> A having a predetermined width outside the width direction of the absorbent main body 3 in the diaper state. And is fixed between the absorbent core 34 and the back sheet 33.

  As shown in FIGS. 2, 3, and 6, the outer packaging material 2 includes an outer layer sheet 21, an inner layer sheet 22, and a plurality of elastic members 23, 24, 25, and 26 disposed between the sheets 21 and 22. Is formed. FIG. 6 is a developed plan view of the outer packaging material 2 viewed from the inner surface side of the outer layer sheet 21 in a state where the inner layer sheet 22 is virtually removed. The outer layer sheet 21 forms the outer surface of the diaper, and the inner layer sheet 22 is disposed on the inner surface side of the outer layer sheet 21.

  In the disposable diaper 1 of the present embodiment, as shown in FIGS. 2, 3, and 6, the outer layer sheet 21 is more than a portion where the waist elastic members 24 and 24 are sandwiched and fixed by the outer layer sheet 21 and the inner layer sheet 22. Furthermore, the extension area | regions 21B and 21B which have the length extended and are extended rather than the inner layer sheet | seat 22 in the outer layer sheet | seat 21 are return | folded by the absorptive main body 3 side. The area other than the extension area 21B in the outer layer sheet 21 is referred to as a non-extension area 21A. The inner layer sheet 22 has the same shape as the non-extending region 21 </ b> A of the outer layer sheet 21.

The skin contact surface side at both longitudinal ends of the absorbent main body 3 is covered with the extended region 21 </ b> B of the folded outer layer sheet 21. In the extension region 21B of the outer layer sheet 21, the portion overlapping the both ends in the longitudinal direction of the absorbent main body 3 is bonded through an adhesive (not shown) over substantially the entire width of the absorbent main body 3, Thus, both ends in the longitudinal direction of the absorbent main body 3 are fixed to the outer packaging material 2.
The skin contact surface side at both longitudinal ends of the absorbent main body 3 is covered with the extended region 21B of the folded outer layer sheet 21, so that both longitudinal ends of the absorbent main body 3 are in direct contact with the wearer. It is possible to prevent the leakage of the absorbent polymer of the absorbent core 34 from both longitudinal ends of the absorbent main body 3.

The inner surface of the outer layer sheet 21 (the surface facing the inner layer sheet 22) is coated with an adhesive Q such as a hot melt adhesive in the coating shape shown in FIG. As shown in FIG. 7, the adhesive Q is applied to almost the entire region corresponding to the side seal portion 11 and the region corresponding to the leg elastic member cutting region 52 (described later).
On the other hand, the adhesive Q is not applied to almost the entire region corresponding to the composite stretchable part 4 (details will be described later) and almost all the region corresponding to the crotch C.

On the surface of the inner layer sheet 22 facing the outer layer sheet 21, an adhesive Q such as a hot-melt adhesive is applied in the coating shape shown in FIG. As shown in FIG. 8, the adhesive Q is applied to almost the entire region other than the region corresponding to the composite stretchable portion 4.
On the other hand, the adhesive Q is not applied to almost the entire region corresponding to the composite stretchable portion 4, similarly to the inner surface of the outer layer sheet 21.

  Thus, the coating shape of the adhesive Q on the surface facing the outer layer sheet 21 in the inner layer sheet 22 includes the coating shape of the adhesive Q on the inner surface of the outer layer sheet 21. Therefore, when the outer layer sheet 21 and the inner layer sheet 22 are bonded together, the adhesive Q applied to the inner surface of the outer layer sheet 21 on the surface facing the outer layer sheet 21 is also disposed on the inner layer sheet 21, The adhesive Q is also applied to the inner surface of the outer layer sheet 21 in the coating shape of the inner layer sheet 22 facing the outer layer sheet 21.

  In the disposable diaper 1 of this embodiment, as shown in FIG.3 and FIG.4, between the outer-layer sheet | seat 21 and the inner-layer sheet | seat 22 in each of the ventral | abdominal part A and the back | dorsal part B, in the side seal part 11, They are joined to each other by a seal, a high frequency seal, an ultrasonic seal or the like.

  Further, waist gathers G <b> 2 are provided on the waist portions F in the ventral side portion A and the back side portion B of the outer packaging material 2. The waist portion F refers to a region from the peripheral edge of the waist opening 12 to a position spaced 30 mm downward, for example, the position of the peripheral edge of the abdominal waist opening 12 and the waist opening 12 on the back side. In the case where the position of the peripheral edge is deviated, the range of the waist portion F is determined on the assumption that there is no region extending deviated.

The waist part F will be described in detail. A plurality of waist elastic members 24 are arranged along the peripheral edge of the waist opening 12 in the waist part F in each of the ventral part A and the back part B. Thus, a waist gather G2 is formed between the pair of side seal portions 11 (over the entire circumference of the waist portion F).
And the composite expansion-contraction part 4 (it mentions later for details) is mainly formed by the outer layer sheet 21, the inner layer sheet 22, and the waist elastic member 24. In the present invention, the waist gather G2 is formed from the composite stretchable part 4 at least in the widthwise outer side of the waist part F. In the present embodiment, the waist gather G2 extends from the composite stretchable part 4 over the entire circumference of the waist part F. Is formed.

  The outer packaging material 2 is provided with a leg gather G3 along a pair of leg openings 13. More specifically, a plurality of leg elastic members 25 are arranged along each peripheral edge of the leg opening 13 curved in the crotch part C. The leg elastic member 25 is fixed in an expanded state between the outer layer sheet 21 and the inner layer sheet 22 via the adhesive Q. Thereby, a leg gather G3 is formed along the leg opening 13.

  In the present embodiment, the leg elastic member 25 includes a member disposed over the half of the peripheral edge of the leg opening 13 near the ventral side A and the back side in relation to the manufacturing method described later. By combining with a member arranged over half of the part B, it is arranged so as to extend over the entire peripheral edge of the leg opening 13, but depending on the manufacturing method, the leg elastic member 25 is One can be disposed over the entire periphery of the leg opening 13.

  A waistline gather D1 formed of a composite stretchable part 4 (details will be described later) is provided on the waistline part D of the abdomen A and back side B of the outer packaging material 2. The waistline portion D is a region from the lower portion of the waist portion F to the upper end of the leg opening 13. The waistline portion D will be described in detail. The waistline portion D is provided with a plurality of waistline elastic members 23 along the width direction. The waistline elastic member 23 extends between the pair of side seal portions 11 (the entire circumference of the waistline portion D), and thereby extends between the pair of side seal portions 11 (to the entire periphery of the waistline portion D). A waistline gather G1 is formed.

  And the composite expansion-contraction part 4 is formed by making the outer layer sheet | seat 21, the inner layer sheet | seat 22, and the waist elastic member 23 into a main body. That is, the waistline gather G1 is formed from the composite stretchable part 4 over the entire circumference of the waistline part D.

  As shown in FIG. 2, the waistline portion D is further divided in the longitudinal direction into an upper waistline portion D1 and a lower waistline portion D2 below the upper waistline portion D1. The upper waistline portion D1 is preferably located in a region that abuts on a portion (hereinafter also referred to as “iliac region”) from the wearer's iliac crest to the upper anterior iliac spine when the diaper 1 is worn. The iliac crest and superior anterior iliac spine are anatomical terms. The iliac crest is a part indicated by reference numeral Q1 in FIG. 9, and the upper anterior iliac spine is a part indicated by reference numeral Q2 in FIG.

Conventionally, in order to prevent slipping off during wearing of a pants-type diaper, particularly when the diaper is for infants, the tightening pressure of the elastic member disposed on the waist portion is increased, and the waist portion It has been considered effective to bring the pants-type diaper into close contact with the wearer's body by tightening.
However, in order to effectively prevent slipping during wearing of pants-type diapers, the tightening pressure of the diaper corresponding to the wearer's iliac region is higher than the conventional tightening pressure of the waist. It has also been found that it is effective to increase it. The reason for this is that the wearer (especially infants) overhangs the abdomen as a physical feature, so if the tightening pressure of the waist that abuts the overhanging abdomen is increased, the tightening pressure is high, so the waist This is because the waist part is shifted down to the part where the part is gradually narrowed down and the abdomen becomes thinner.

FIG. 10 shows a state in which the baby's body is regarded as a cone. In the figure, θ represents an angle formed by a perpendicular to the tangent at the waist (point A) and a horizontal line toward the center of the body. F indicates the tightening force of the elastic member, P indicates the frictional force resulting from the tightening force F, f1 indicates the displacement force due to the tightening force F, and f2 indicates the vertical drag. Here, since f1 = Fsinθ and P = νN = νf2 = νFcosθ (ν represents a friction coefficient), the “slip-off force Z” directed downward at the point A is represented by the following equation.
Z = f1−P = Fsinθ−νFcosθ = F (sinθ−νcosθ)
From this equation, it can be understood that when the waist portion is in a state where slipping occurs, the slipping force increases as the tightening force F increases.

  A portion (iliac region) from the wearer's iliac crest to the upper anterior iliac spine has a certain width, and the upper waistline portion D1 of the diaper 1 is fixed to the iliac region within the range of the width. The diaper 1 can be effectively prevented from falling off. From this viewpoint, in the diaper 1 of the present embodiment, the width of the upper waistline portion D1 (that is, the length of the upper waistline portion D1 along the longitudinal direction of the diaper 1) is set to 12 to 35 mm. When this width is 20 to 35 mm, particularly 25 to 30 mm, the diaper 1 can be prevented from slipping off more effectively, and the appearance of the diaper 1 in the wearing state and the wearing operation of the diaper 1 (easy to wear) Etc.) can be further improved.

  In the state where the diaper 1 is worn, the size of the diaper 1 and the wearer are determined so that the upper waistline portion D1 abuts on a portion (iliac region) from the wearer's iliac crest to the upper anterior iliac spine. The relationship with the physique is important. For example, when considering an infant who is a main wearer of a pants-type diaper, as shown in FIG. 6, the center position of the upper waistline portion D1 of the abdominal side A (the longitudinal direction of the diaper 1) Center distance CL between the longitudinal center line CL of the diaper 1 and 180 to 230 mm, and in the unfolded state of the diaper 1, the center position of the upper waistline portion D1 of the back side B (the diaper 1 The upper waistline D1 can be successfully brought into contact with the wearer's iliac region by setting the distance K2 between the longitudinal center line CL of the diaper 1 and the longitudinal center line CL of the diaper 1 to 180 to 230 mm. it can.

This value is determined by carrying out body measurements of about 350 infants who are the main wearees of pants-type diapers. Specifically, as shown in FIG. 11, this value is obtained by setting the left and right center points of the ventral side at the horizontal position height of the upper anterior iliac spine as “the upper anterior iliac spine height front center”, The center point of the dorsal side at the horizontal position of the iliac spine is defined as the “upper center of the upper anterior iliac spine” and the upper anterior iliac bone via the crotch from the center of the upper anterior iliac spine. The length to the center after the height of the spine is defined as the “upper and lower length of the superior anterior iliac spine”, and the numerical value obtained by adding the necessary length considering the thickness of the diaper material, etc. It is a bisection. By setting the distances K1 and K2 to 185 to 220 mm, particularly 195 to 215 mm, the upper waistline portion D1 can be brought into more successful contact with the wearer's iliac region.
In the case of an adult diaper, the upper waistline D1 can be brought into more successful contact with the wearer's iliac region by setting the distances K1 and K2 to 300 to 350 mm, particularly 305 to 335 mm.

In addition, in the case where the position of the peripheral edge of the waist opening 12 on the ventral side and the position of the peripheral edge of the waist opening 12 on the back side are not substantially deviated from the longitudinal center line CL of the diaper 1. , Refers to a straight line along the diaper width direction that passes through the midpoint in the longitudinal direction of the diaper 1 in the developed state.
On the other hand, for example, when the position of the peripheral edge of the waist opening 12 on the ventral side and the position of the peripheral edge of the waist opening 12 on the back side are shifted, there is no region extending out of alignment. Assuming that the longitudinal center line CL of the diaper is defined.

  In the diaper 1 according to the present embodiment, the diaper 1 is fixed to the wearer's body mainly by the fastening force of the waistline elastic member 23 disposed in the upper waistline portion D1. In other words, unlike the conventional pants-type diaper, the tightening force by the waist elastic member 24 arranged on the waist portion F is the main for fixing the diaper 1 to the wearer's body in the diaper 1 of the present embodiment. It is not a means. On the other hand, if the tightening force of the waist portion F is increased, the diaper 1 may be displaced.

  When the diaper 1 is worn, the lower waistline portion D2 is preferably in contact with the lower region (lower abdomen) of the wearer's iliac region. The width of the lower waistline portion D2 (that is, the length of the lower waistline portion D2 along the longitudinal direction of the diaper 1) is preferably 40 to 70 mm, particularly 45 to 65 mm.

  Next, the front crotch E will be described. The front crotch portion E refers to the foremost region when the crotch portion C is divided into four in the longitudinal direction. In the front crotch part E, a plurality of front crotch elastic members 26 are arranged over the entire width direction. The front crotch elastic member 26 is fixed in an extended state between the outer layer sheet 21 and the inner layer sheet 22 via the adhesive Q. Thereby, the front crotch gather G4 is formed in the front crotch E.

A leg elastic member cutting region 52 is formed at a position that is the center of the crotch C in the width direction. The leg elastic member cutting region 52 is a continuous body 25S of leg elastic members 25 arranged in a curved shape in the entire width direction of the outer packaging material 2 in the raw material state, as will be described in detail in the description of the manufacturing method described later. Is a region cut at a position that is the central portion in the width direction of the crotch portion C. In order to form the leg elastic member cutting region 52, for example, a large number of convex portions and cutter blades that divide the elastic member are used.
By forming the leg elastic member cutting region 52, the leg elastic member continuous body 25 </ b> S disposed in a curved shape in the entire width direction of the outer packaging material 2, in the width direction center of the crotch C in the width direction. A pair of separated leg elastic members 25, 25 are formed.

In the present embodiment, the composite stretchable part 4 is not provided in the crotch part C of the outer packaging material 2.
As the leg elastic member 25 and the front crotch elastic member 26, elastic materials such as natural rubber, polyurethane resin, foamed urethane resin, and hot melt elastic member are formed into a thread shape (thread rubber) or a belt shape (flat rubber), respectively. Those formed are preferably used.

Next, the composite elastic part 4 which forms the waistline gather G1 and the waist gather G2 in this embodiment is explained in full detail. As shown in FIGS. 12 and 17, the composite stretchable part 4 includes the following configurations (1) to (3).
(1) The outer layer sheet 21 and the inner layer sheet 22 are joined to each other by an intermittent joining portion 41 in the stretching direction (X direction) of the composite stretchable portion 4 and the direction (Y direction) perpendicular thereto.
(2) The elastic member 42 is disposed so as not to pass through the joint portion 41, and is not fixed to the outer layer sheet 21 and the inner layer sheet 22 in a portion excluding both ends of the elastic member 42.
(3) Each of the outer layer sheet 21 and the inner layer sheet 22 forms a plurality of ridges 43 extending continuously over a plurality of elastic members 42.
As shown in FIG. 13, the plurality of ridges 43 extend along the longitudinal direction of the outer packaging material 2 in the width direction outer side portion 2B of the waist portion F and the width direction outer side portion 2B (details will be described later) of the waistline portion D. Thus, it extends from the outer end of the waist portion F (the peripheral edge of the waist opening 12) to the inner end of the waistline portion D (the end on the longitudinal center side of the outer packaging material 2).

  In the present embodiment, the waistline gather G1 formed from the composite stretchable part 4 is composed mainly of the outer layer sheet 21, the inner layer sheet 22, and the waistline elastic member 23, and the waist gather G2 formed from the composite stretchable part 4. Is mainly composed of an outer layer sheet 21, an inner layer sheet 22, and a waist elastic member 24. Thus, although the elastic member which comprises it changes with gathers, in the following description of the composite expansion-contraction part 4, the elastic member which comprises the composite expansion-contraction part 4 is demonstrated as the "elastic member 42".

  In the composite stretchable part 4, it is preferable that all the elastic members 42 do not pass through all the joints 41. However, for example, some elastic members 42 are part of the joints 41 due to manufacturing errors. May pass through. Even if some elastic members 42 pass through some of the joint portions 41, the effects of the present invention are sufficiently achieved. Therefore, when the elastic member 42 does not pass through 80% (pieces / pieces) or more of the joint portions 41 provided in the composite stretchable portion 4, the elastic member 42 does not pass through the joint portion 41. It shall be comprised as follows.

As shown in FIGS. 12 and 17, the outer layer sheet 21 and the inner layer sheet 22 constituting the composite stretchable part 4 are respectively in the stretch direction (X direction) of the composite stretchable part 4 and the direction (Y direction) perpendicular thereto. The joints 41 are intermittently joined together. The joint portion 41 is preferably formed by heat sealing.
The plurality of elastic members 42 are arranged in parallel to each other, and are arranged so as to extend along the longitudinal direction of the composite stretchable part 4. When a plurality of elastic members 42 are arranged in parallel to each other as in this embodiment, the expansion / contraction direction of the composite expansion / contraction part 4 is the same direction as the direction in which the elastic member 42 extends. When the plurality of elastic members 42 are not arranged in parallel to each other, the expansion / contraction direction of the composite expansion / contraction part 4 is in the direction in which the flange 43 extends in a flange 43 (described later) extending over the plurality of elastic members 42. The direction is orthogonal.

  FIG. 12 is a diagram illustrating an arrangement pattern of the joint portions 41. The joint portions 41 are formed so as to form rows in the stretching direction (X direction) of the composite stretchable portion 4 and the direction (Y direction) perpendicular thereto, and the joint portions 41 constituting the row in the perpendicular direction are formed. It is formed between each elastic member 42. In a natural state (a state in which no external force is applied), the elastic member 42 contracts, and each of the outer layer sheet 21 and the inner layer sheet 22 continuously extends over the plurality of elastic members 42. (Gather) 43 is formed. In the present embodiment, a single collar 43 is formed between the joint portions 41, 41 adjacent to each other in the stretching direction (X direction) of the composite stretchable portion 4.

  From the viewpoint of reliably forming the flanges 43 extending continuously over the plurality of elastic members 42, when the composite stretchable portion 4 is extended, the pitch P2 of the joint portions 41 in the stretch direction (X direction) of the composite stretchable portion 4 is shown. (See FIG. 12) is preferably 1 to 20 mm, particularly 3 to 10 mm, and the length L2 (see FIG. 12) of each joint 41 is 0.1 to 5 mm, particularly 0.2 to 1.5 mm. It is preferable that The ratio (P2 / L2) between the pitch P2 and the length L2 is preferably 1.1 to 200, particularly 2 to 50.

  In the composite stretchable part 4, the pitch P3 (see FIG. 12) of the joints 41 in the direction (Y direction) orthogonal to the stretch direction is preferably 1 to 40 mm, particularly 2 to 15 mm. The length L3 (see FIG. 12) is preferably 0.5 to 20 mm, particularly 1 to 10 mm. The ratio (P3 / L3) between the pitch P3 and the length L3 is preferably 1.05 to 80, particularly 1.05 to 15.

  In the composite stretchable part 4, the outer layer sheet 21 and the inner layer sheet 22 are preferably not joined to each other at a part other than the joint part 41. Each elastic member 42 is disposed in the composite stretchable part 4 so as not to pass through the joint part 41 between the outer layer sheet 21 and the inner layer sheet 22, and the outer layer sheet 21 and the inner layer sheet are excluded from the portions excluding both ends of the elastic member 42. 22 is not fixed. That is, each elastic member 42 is fixed to the outer layer sheet 21 and the inner layer sheet 22 only at both ends thereof.

Both end portions of the elastic member 42 are fixed between the outer layer sheet 21 and the inner layer sheet 22 in a state sandwiched between the outer layer sheet 21 and the inner layer sheet 22 at both end portions 44 (only one is shown) of the composite stretchable portion 4. Yes. Both ends 44 of the composite stretchable part 4 may differ depending on the gathers formed thereby. In the embodiment shown in FIG. 1, both ends 44 of the composite stretchable part 4 forming the waistline gather G1 are on both sides. Both end portions 44 of the composite stretchable portion 4 which is the seal portion 11 and forms the waist gather G2 are also the side seal portions 11 and 11.
In addition, you may form the both ends 44 of the composite expansion-contraction part 4 so that expansion-contraction is possible.

  Each ridge 43 in the outer layer sheet 21 and the inner layer sheet 22 is formed so as to protrude from both surfaces of the composite stretchable portion 4, and a convex curved surface having an arcuate cross section is formed at the tip in the protruding direction of each ridge 43. Has been. The convex curved surface continuously extends in a direction (Y direction) orthogonal to the expansion / contraction direction of the composite expansion / contraction part 4. In the present embodiment, one ridge 43 is formed between the joint portions 41, 41 adjacent to each other in the expansion / contraction direction (X direction) of the composite expansion / contraction portion 4, and these ridges 43 are elastic members 42. Without being divided at the overlapping portion, and continuously extending in the direction (Y direction) orthogonal to the expansion / contraction direction of the composite expansion / contraction part 4.

  In the composite stretchable part 4 in this embodiment, each of a large number of ridges 43, 43 formed by contraction of the elastic member 42 extends continuously in a direction (Y direction) perpendicular to the stretchable direction of the composite stretchable part 4. So it looks very beautiful.

Moreover, the composite elastic part 4 in this embodiment can prevent the increase in rigidity, and the degree of freedom of deformation of the flange 43 with respect to external force is improved. The prevention of the increase in rigidity and the improvement of the degree of freedom of deformation of the flange 43 are such that the elastic member 42 is formed between the valley between the flange 43 and the flange 43 in the outer layer sheet 21 and the flange 43 and the flange 43 in the inner layer sheet 22. It exists in a state of being sandwiched between the valleys between them, and is present in a state where it is not joined to any of the outer layer sheet 21 and the inner layer sheet 22 including the portion sandwiched between those valleys. In addition, the outer layer sheet 21 and the inner layer sheet 22 in the composite stretchable part 4 are not continuously joined in any direction of the stretchable direction (X direction) of the composite stretchable part 4 and the direction (Y direction) perpendicular thereto. Is based on that.
Furthermore, due to a synergistic effect with the tip of the collar 43 forming a convex curved surface, a volume appears in the thickness direction of the outer layer sheet 21 and the inner layer sheet 22 and the touch when touching the surface of the composite stretchable part 4 is felt. It is very soft and feels very good.

  Moreover, since the elastic member 42 in the composite stretchable part 4 is present in a state where it is not joined to the outer layer sheet 21 and the inner layer sheet 22, the amount of hot melt adhesive used can be suppressed to zero or a small amount. In particular, as in the present embodiment, when the outer layer sheet 21 and the inner layer sheet 22 are joined to each other by the joining portion 41 by heat fusion, the effect of reducing the amount of adhesive used is more remarkable. Since the amount of hot-melt adhesive used is small, air permeability and moisture permeability are not impaired.

The material for forming the composite stretchable part 4 in this embodiment will be described.
As the outer layer sheet 21 and the inner layer sheet 22, an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, a melt blown nonwoven fabric, and the like are preferable from the viewpoint of forming a flexible ridge 43 having a beautiful appearance and good touch.

  In the composite stretchable part 4, the outer layer sheet 21 and the inner layer sheet 22 are deformed by the contraction of the elastic member 42 to form the flange 43. That is, the rigidity of the outer layer sheet 21 and the inner layer sheet 22 is one of the factors that determine the formability and cushioning properties of the collar 43 of the composite stretchable part 4. The rigidity of each sheet can be expressed by its buckling strength. The buckling strength of the sheet used for the composite stretchable part 4 is preferably 100 cN or less, particularly preferably 70 cN or less. Here, the buckling strength is measured by a compression test mode of a Tensilon universal testing device (manufactured by Orientec Co., Ltd.) as shown below.

Buckling strength test method (CD):
A rectangular test piece having a length of 150 mm in the machine flow direction (MD) and a length of 30 mm in the direction orthogonal to the machine flow direction (CD) is rounded to create a cylinder having a diameter of 45 mm. The lower end is stopped with a stapler or the like to obtain a measurement sample. This is measured by the compression test mode of the Tensilon universal testing apparatus in a measurement environment of 20 ° C. and 65% RH under measurement conditions of a compression speed of 10 mm / min and a measurement distance of 20 mm. The maximum strength when the measurement sample is compressed by 20 mm is measured for each measurement sample, the average value is obtained, and this is taken as the buckling strength.

As described above, non-woven cloth is preferably used as the outer layer sheet 21 and the inner layer sheet 22. The basis weight of the nonwoven fabric is preferably 5 to 50 g / m ² , particularly preferably 18 to 30 g / m ² . The buckling strength of the nonwoven fabric having such a basis weight is preferably 50 cN or less, particularly preferably 30 cN or less in the CD direction, and preferably 70 cN or less, particularly preferably 50 cN or less in the MD direction.

In addition, the outer layer sheet 21 and the inner layer sheet 22 are made of a heat-fusible resin from the viewpoint of facilitating joining by heat-sealing (formation of the joining portion 41). Is preferred. Examples of the heat-fusible resin include polyethylene and polypropylene. The fiber may be a core-sheath type composite fiber whose sheath is made of a heat-fusible resin.
The outer layer sheet 21 and the inner layer sheet 22 may be formed of the same material or different materials.

The outer layer sheet 21 and the inner layer sheet 22 have different shapes in the embodiment shown in FIG. 1, but may have the same shape in the present invention. In that case, as an alternative to the extension region 21B of the outer layer sheet 21 in the embodiment shown in FIG. 1, a pressing sheet separate from the outer layer sheet 21 and the inner layer sheet 22 is used, and the pressing body allows the absorbent main body to be used. It is preferable to cover the skin contact surface side at both longitudinal ends of 3. As for this pressing sheet, the part which overlaps with the longitudinal direction both ends of the absorptive main body 3 is adhere | attached through the adhesive agent over the substantially full width of the absorptive main body 3, and, thereby, the longitudinal direction both ends of the absorptive main body 3 Is preferably fixed to the outer packaging material 2.
Further, the outer layer sheet 21 and the inner layer sheet 22 are not limited to two separate sheets, but one sheet is folded to form two opposing surfaces, and a portion constituting one surface is an outer layer. The portion constituting the sheet 21 and the other surface may be the inner layer sheet 22.

  As a material for forming the elastic member 42 in the composite stretchable part 4, various known elastic materials used for absorbent articles such as disposable diapers and sanitary napkins can be used without particular limitation. Examples of the elastic material include synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane. As the form of the elastic member 42, a thread-like (thread rubber etc.) or string-like (flat rubber etc.) having a cross section of a rectangle, square, circle, polygon or the like, or a multifilament type thread-like one or the like is used. it can.

  Another factor that determines the formability of the collar 43 of the composite stretchable part 4 is the stretch ratio and stretch stress of the elastic member 42. In order to make the cross-sectional shape of the flange 43 convex, the required expansion ratio and expansion / contraction stress of the elastic member 42 are required. The elastic member 42 is preferably bonded to the outer layer sheet 21 and the inner layer sheet 22 in a stretched state of 20 to 1000%, particularly preferably 50 to 400%. Then, the elastic member 42 contracts, the contracted portions of the outer layer sheet 21 and the inner layer sheet 22 remain, and the remaining outer layer sheet 21 and inner layer sheet 22 extend in the direction opposite to the bonding surface of the joint portion 41 (outside). (Ii) The ridge 43 is formed by deforming into a convex cross section.

  As described above, the height of the flange 43 is an important element related to the moldability and cushioning properties, and the selection of the arrangement pattern and interval of the joint portions 41, the material of the outer layer sheet 21 and the inner layer sheet 22, the elastic member, and the like. Thus, it can be arbitrarily designed. The height of the flange 43 is preferably about 1 to 15 mm on one side. In order to increase the height of the flange 43, the elastic member 42 is contracted to the extent that the interval between the adjacent joint portions 41 is narrowed to form the convex flange 43, so that the soft composite stretchable portion 4 with a sense of volume is formed. Can be formed. When forming the flange 43 having a height on one side, the distance between the joint portions 41 needs to be at least 2 × h. When the distance between the joint portions 41 is 2 × h, the elastic member 42 is required. Needs to shrink to such an extent that adjacent joints 41 are adjacent.

  One of the preferable elastic members 42 is natural rubber (or synthetic rubber). Examples of natural rubber (synthetic rubber) include low modulus elastic members having a thickness of 0.05 to 1.5 mm and a width of 0.2 to 5 mm. In this elastic member, the stress at 100% elongation in a single yarn is preferably 1 to 70 gf, more preferably 1 to 40 gf, and particularly preferably 1 to 30 gf. By providing a plurality of single yarns of the elastic member having a low modulus at a high elongation ratio of preferably 100% or more, particularly preferably 200% or more, a composite stretchable part 4 having a beautiful heel 43 that stretches softly is obtained. Can do.

  Other preferred elastic members include polyurethane spandex elastic fibers. As the elastic fiber, one having a single yarn size of 10 to 3360 denier, particularly preferably 70 to 1120 denier is used. Denier is a unit representing the thickness of a yarn, and a yarn of 1 g at 9000 m is called 1 denier. It is preferable to use the spandex elastic fiber by stretching it to 30 to 500%.

Next, the expansion ratio of the waist part F will be described. In the disposable diaper of the present embodiment, the waist portion F has an elongation rate at the center portion 2A in the width direction of the outer packaging material 2 lower than an elongation rate at the outer side portion 2B in the width direction of the outer packaging material 2. Such a difference in elongation rate can be easily realized by forming the waist gather G2 from the composite stretchable part 4.
The central portion 2A (see FIG. 13) in the width direction of the outer packaging material 2 is a region facing the absorbent main body 3 in the outer packaging material 2 in the unfolded state, and as in the embodiment shown in FIG. In the case where the longitudinal end of the outer casing 2 is retracted inward in the longitudinal direction from the longitudinal end of the outer packaging material 2, the longitudinal end of the absorbent main body 3, the longitudinal end of the outer packaging material 2, And the area | region enclosed by the straight line extended toward the longitudinal direction both ends of the outer packaging material 2 from each longitudinal direction both ends of the absorptive main body 3 is also contained in the width direction center part 2A of the outer packaging material 2.

The center part in the width direction of the waistline part D is a part located in the center part 2A in the width direction of the outer packaging material 2 in the waistline part D, and the center part in the width direction of the waist part F is the outer packaging material in the waist part F. 2 is a portion located in the center portion 2A in the width direction.
The width direction outer side part 2B of the outer packaging material 2 is an area | region located in the width direction both sides of 2 A of width direction center parts, as shown in FIG.
The width direction outer side part of the waist part D is a part located in the width direction outer part 2B of the outer packaging material 2 in the waist part D, and the width direction outer side part of the waist part F is the outer packaging material in the waist part F. 2 is a portion located on the outer side 2B in the width direction.

The elongation rate of the waist part F is measured by the following method.
[Measurement method of elongation rate of waist F]
(1) About the diaper 1 of the unstretched state, the mark of 20 mm in length is attached to the width direction center part 2A of the waist F along the width direction.
(2) The both ends of this mark are gripped and the diaper 1 is extended in the width direction.
(3) The length of the mark after extension (distance between both ends) L4 is measured.
(4) Let (L4 / 20) × 100 (%) be the elongation ratio of the center portion 2A in the width direction of the waist F.
(5) The elongation rate of the width direction outer side portion 2B of the waist F is also measured in the same manner as the elongation rate of the width direction center portion 2A of the waist F (differing in that the position to be marked is the width direction outer side portion 2B). Can do.

  The elongation ratio of the center portion 2A in the width direction of the waist portion F is preferably 130 to 280%, more preferably 150 to 250%. The elongation ratio of the width direction outer side portion 2B of the waist portion F is preferably 150 to 400%, more preferably 200 to 320%. The difference between the elongation rate of the width direction outer side portion 2B of the waist portion F and the elongation rate of the width direction center portion 2A of the waist portion F is preferably 20 to 120%, more preferably 50 to 70%.

  Next, the tensile load of the waist part F will be described. The waist portion F preferably has a load of 20 gf or more, and more preferably 30 gf or more when the circumference is extended to 300 mm. The reason why the load when the circumferential length of the waist portion F is extended to 300 mm is defined in the infant diaper because the circumferential length of the waist portion F in the non-wearing state is about 300 mm. If the load when the circumference of the waist portion F is extended to 300 mm is less than 20 gf, the appearance is poor.

In addition, the waist portion F preferably has a load of 200 gf or less, more preferably 180 gf or less, when the circumference is extended to 500 mm. The reason why the load when the circumference of the waist F is extended to 500 mm is specified is that the circumference around the stomach of a large infant, that is, the maximum circumference of the waist F in the worn state is about 500 mm. is there. If the load when the circumference of the waist portion F is extended to 500 mm is more than 200 gf, the force required to stretch and expand the waist portion F (waist opening 12) when the diaper is mounted is not preferable.
The tensile load of the waist part F can be set, for example, by adjusting the material, thickness, elongation rate, disposition interval, disposition number, and the like of the waist elastic member 24.

The tensile load of the waist part F is measured by the following method.
[Measurement method of tensile load of waist F]
(1) The waist part F is cut out from the diaper in a ring-like state where the side seal part 11 is connected, and this is used as a sample. This sample was placed on a horizontal surface, and the length between both ends of the sample (between the pair of side seal portions 11 and 11) in a naturally contracted state was measured. To do.
(2) Both ends of the sample are fixed between chucks of a Tensilon tensile tester [Orientec Co., Ltd., “RTC-1150A”], and the load at that time is set to zero.
(3) The load when extending between the both ends of the sample at the speed of 300 mm / min from the initial length in the same direction as the width direction of the diaper until the circumference of the waist F becomes 300 mm or 500 mm, It is referred to as “load when the length is extended to 300 mm” or “load when the circumference is extended to 500 mm”.

Further, when the tensile loads of the waist portion F, the upper waistline portion D1, and the lower waistline portion D2 are compared, the tensile load of the upper waistline portion D1 is the highest, then the tensile load of the waist portion F is high, and the lower waistline portion D2 It is preferable that the tensile load is the lowest. The tensile load in the upper waistline portion D1 and the lower waistline portion D2 can be set by adjusting, for example, the material, thickness, elongation rate, placement interval, number of placements, and the like of the waistline elastic member 23.
By providing such an order in the tensile load of each part, the diaper 1 during wearing is effectively prevented from slipping off, and the diaper 1 adheres to the wearer's body without a sense of incongruity, and liquid leakage is effective. Is prevented. The tensile load of the upper waistline portion D1 and the lower waistline portion D2 is measured in the same manner as the tensile load of the waist portion F.

  Next, physical properties when the space between the pair of side seal portions 11 and 11 is extended in a diaper state will be described. The circumferential length of the waist portion F when the pair of side seal portions 11, 11 are extended in the width direction up to a load of 2400 gf is preferably 650 mm or more, and more preferably 660 mm or more. The larger the circumference of the waist F, the easier it is to insert the infant's leg and the easier it is to put on the diaper. “The circumference of the waist portion F when the width between the pair of side seal portions 11 and 11 is extended in the width direction to a load of 2400 gf” means that the entire diaper is grasped by gripping the pair of side seal portions 11 and 11. It is the circumference when the extension load reaches 2400 gf by gradually extending in the width direction.

  And it is preferable that the energy required for expansion | extension of this waist part F is 4 N * m or less, and it is still more preferable that it is 3.5 N * m or less. The reason why the load of 2400 gf is defined is that the maximum load that the mother can expand the diaper in the width direction is generally about 2400 gf. If the energy required for stretching the waist portion F exceeds 4 N · m, it is difficult for the mother to expand the diaper in the width direction. The smaller the energy, the easier the diaper 1 can be stretched in the width direction with a small force, and thus the diaper 1 is easier to put on.

The energy required for extension of the waist part F is measured by the following method.
[Measurement method of energy required for stretching waist part F]
(1) The diaper itself is used as a sample. This sample was placed on a horizontal surface, and the length between both ends of the sample (between the pair of side seal portions 11 and 11) in a naturally contracted state was measured. To do.
(2) Both ends of the sample are fixed between chucks of the Tensilon tensile tester “RTC-1150A”, and the load at that time is set to zero.
(3) The both ends of the sample are extended from the initial length at a speed of 300 mm / min in the same direction as the width direction of the diaper until the load reaches 2400 gf.
(4) From the area of the SS curve (load-strain curve) obtained at that time, the energy required for expansion of the waist portion F is obtained.

  According to the pants-type disposable diaper of the first embodiment having the above configuration, the waistline gather G1 and the waist gather G2 are formed mainly of the composite stretchable part 4, and even if the amount of hot melt adhesive used is small. Since the gather stretchability can be expressed, the ventilating portion A and the dorsal portion B are excellent in air permeability. Moreover, the raw material original texture of the outer-layer sheet 21 and the inner-layer sheet 22 of the outer packaging material 2 can be utilized, and it is soft and not stiff.

  In the composite stretchable part 4, the contraction force of the elastic member 42 is not (or hardly) inhibited, so that the contraction force is utilized to the maximum extent. For example, when the expansion and contraction characteristics are graphed by taking the circumference of the waistline D on the horizontal axis and the tensile load of the waistline D on the vertical axis, it can be seen that the slope of the characteristic curve is gentle, that is, the stretchability is high. In addition, the stress difference between the characteristic curve at the time of expansion and the characteristic curve at the time of contraction is small, i.e., the stress fluctuation with respect to the fluctuation of the circumference is small. It can be seen that the size application range of the person increases.

Therefore, since the shrinkage force is high, it fits gently to the wearer and is difficult to slip off. Moreover, since the whole diaper shrinks to the maximum extent, there is an advantage that it looks compact. Moreover, since the usage-amount of the elastic member 42 can be reduced, it is advantageous also in terms of cost.
Since the heel 43 is formed on the outer surface of the composite stretchable portion 4 and the heel 43 is a contact surface with the wearer, the composite stretchable portion 4 has a high cushioning property when worn and fits gently to the wearer's skin. Less damage. Moreover, since the collar 43 is also arranged on the outer surface of the outer packaging material 2 (the outer surface when worn), the outer surface feels excellent.

  Further, if the waistline elastic member 23 is divided at the center portion in the width direction of the waistline portion D and the waistline elastic member 23 is not provided over the entire circumference of the waistline portion D, the center portion in the width direction of the waistline portion D is assumed. In this case, almost no tightening force is generated by the waistline gather G1. Therefore, it is necessary to secure the entire tightening force of the waistline portion D by the tightening force of the waistline gather G1 at the outer side in the width direction of the waistline portion D. However, in such a configuration, it is necessary to excessively increase the tightening force of the waistline gather G1 at the widthwise outer side portion of the waistline portion D, and as a result, it is necessary to stretch and widen the waist portion F (waist opening 12). The force is increased, it is difficult to put on a diaper, and rubber marks due to the waistline gather G1 are easily attached.

  Thus, in this embodiment, the waistline portion D and the waist portion F in the abdomen side portion A and the backside portion B of the outer packaging material 2 are respectively surrounded by the waistline elastic member 23 and the waist elastic member. 24 is provided with a waistline gather G1 and a waist gather G2, respectively, and the waistline gather G1 is formed from the composite stretchable part 4 at least in the widthwise outer side of the waistline part D. The waist gather G2 is formed from the composite stretchable part 4 at least in the widthwise outer side of the waist part F, and the plurality of ridges 43 in the composite stretchable part 4 are the widthwise outer side part and waistline part D of the waist part F. In the outer side in the width direction, it extends from the outer end portion of the waist portion F to the inner end portion of the waistline portion D along the longitudinal direction of the outer packaging material 2.

  Therefore, the difference in the tightening force due to the waistline gather G1 between the widthwise center portion and the widthwise outside portion of the waistline portion D is reduced, and the tightening force due to the waistline gather G1 is reduced between the width direction center portion and the width direction outside portion of the waistline portion D Can be close to uniform. Therefore, it is not necessary to set the tightening force by the waistline gather G1 excessively at the outer side in the width direction of the waistline part D, the force required to stretch and expand the waist part F (waist opening 12) can be reduced, and the diaper can be reduced. It is easy to put on, and it is difficult for rubber marks due to the waistline gather G1. In addition, an appropriate tightening force can be obtained also in the central portion in the width direction of the waistline portion D (normally, the absorbent main body 3 is located).

  In addition, the plurality of ridges 43 in the composite stretchable portion 4 are arranged at the outer end portion of the waist portion F along the longitudinal direction of the outer packaging material 2 in the width direction outer side portion of the waist portion F and the width direction outer side portion of the waistline portion D. Therefore, the waist gather G2 and the waist gather G1 formed from the composite stretchable part 4 are excellent in appearance, feel and texture.

  Moreover, since the waist gather G2 is formed from the composite expansion-contraction part 4 over the perimeter of the waist part F, while improving the said effect of this invention further, a wearer's skin and the waist part of the outer packaging material 2 A gap having an appropriate size can be secured on the inner side of the heel 43 in the composite stretchable portion 4 between the outer stretch material 4 and the longitudinal direction of the outer packaging material 2 between the wearer's skin and the waist portion F of the outer packaging material 2. Excellent breathability.

  FIG. 14 shows the temperature of the space between the wearer's skin and the diaper (diaper internal space) in each of the summer cooling environment conditions (28 ° C., 60 RH%) and the winter heating environment conditions (20 ° C., 40 RH%). It is the graph which measured humidity. In the graph shown in FIG. 14, the horizontal axis indicates the elapsed time (minutes) from the start of wearing the diaper, the right vertical axis indicates the temperature (° C.) of the diaper internal space, and the left vertical axis indicates the humidity (in the diaper internal space). RH%). In this measurement, using a baby model, artificial urine: 120 cc was injected into the inner space of the diaper after 15 minutes from the start of wearing the diaper.

In FIG. 14, the temperature and humidity in the summer cooling environment condition are indicated by a solid line and a one-dot chain line, respectively, and the temperature and humidity in the winter heating environment condition are indicated by a broken line and a two-dot chain line, respectively.
From the graph shown in FIG. 14, the pants-type disposable diaper of the present invention is excellent in air permeability, so that the humidity increases immediately after urination but gradually decreases. This behavior shows the same tendency in both the hot environment in summer and the cold environment in winter, and it can be seen that the behavior is gentle to the wearer's skin under any environment.

  Next, one manufacturing method for continuously producing the pants-type disposable diaper shown in FIG. 1 will be described with reference to the drawings. FIG. 15 is a perspective view showing the entire manufacturing method. FIG. 16 is a conceptual diagram showing mainly the step of forming the composite stretchable part and the leg elastic member cutting region in the manufacturing method. FIG. 17 is a conceptual diagram showing mainly the step of forming the composite stretchable part in the present manufacturing method.

  In this manufacturing method, as shown in FIG. 15, the continuous body 21S of the outer layer sheet 21 and the continuous body 22S of the inner layer sheet 22 are interposed between the continuous bodies 23S, 24S, 25S of the elastic members 23, 24, 25, 26. , 26S are sandwiched and joined to form a continuous body 2S of the outer packaging material 2, and the absorbent main body 3 is then attached to the inner layer sheet continuous body 22S side of the outer packaging material continuous body 2S by the main body joining portion 15 (see FIG. 4). It is the manufacturing method of the underpants type disposable diaper which joins and forms the diaper continuous body 1S, and then divides the diaper continuous body 1S and forms each diaper 1.

This manufacturing method will be described in detail. The outer layer sheet continuous body 21 </ b> S is used as the original sheet of the outer layer sheet 21, and the inner layer sheet continuous body 22 </ b> S is used as the original sheet of the inner layer sheet 22.
Each continuous body 23S, 24S, 25S, 26S of each elastic member 23, 24, 25, 26 is introduced between the outer layer sheet continuous body 21S and the inner layer sheet continuous body 22S in an expanded state. In addition, in FIG. 16, illustration of the continuous body 26S of the front crotch elastic member 26 is abbreviate | omitted. Before the outer layer sheet continuous body 21S and the inner layer sheet continuous body 22S merge, the coating positions shown in FIGS. 7 and 8 are formed on the respective facing surfaces by the adhesive coating device 64 (see FIG. 16) or the like. The hot melt adhesive Q is applied to the surface. Further, the continuous body 25S of the leg elastic member 25 is swung so as to follow the shape of the leg opening 13 by a swing guide 65 (see FIG. 16), while the outer layer sheet continuous body 21S and the inner layer sheet continuous body 22S. Introduced between.

Both sheet continuums 21S and 22S are compressed between the pair of nip rolls 61 and 61 with the elastic member continuums 23S, 24S, 25S, and 26S sandwiched therebetween. As a result, an outer packaging material continuum 2S is obtained in which the elastic member continuums 23S, 24S, 25S, and 26S are sandwiched and joined between the sheet continuums 21S and 22S. Here, the waistline elastic member 23 is not joined by the hot-melt adhesive Q in the region between the pair of side seal portions 11. Similarly, the waist elastic member 24 is not joined by the hot melt adhesive Q in a region between the pair of side seal portions 11.
At this time, the composite stretchable part 4 and the leg elastic member cutting region 52 are not formed in the outer packaging material continuous body 2S.

Next, the outer wrapping material continuous body 2 </ b> S in which the composite stretchable part 4 or the like is not formed is introduced between the composite stretchable part forming roll 62 and the anvil roll 63. The composite elastic part forming roll 62 includes a composite elastic part forming part 62A that forms the composite elastic part 4 and a leg elastic member cutting area forming part 62C that forms the leg elastic member cutting area 52 on the peripheral surface thereof. Yes.
The anvil roll 63 is a receiving roll for the composite stretchable part forming roll 62, and its peripheral surface is a smooth surface.

  A plurality of embossed pins 62D (see FIG. 17) are provided in the composite stretchable part forming part 62A of the composite stretchable part forming roll 62 in correspondence with the joint part 41 of the composite stretchable part 4, and the composite stretchable part forming part 62A. According to this, the joining part 41 can be formed in the area | region corresponding to the composite expansion-contraction part 4 in the outer packaging material continuous body 2S in which the composite expansion-contraction part 4 is not formed. The emboss spin 62D may be a heat emboss spin or an ultrasonic emboss spin. FIG. 17 is a conceptual diagram showing only elements closely related to the process of forming the composite stretchable part 4. Therefore, for example, only the composite stretchable part forming part 62A is illustrated on the peripheral surface of the composite stretchable part forming roll 62, and only the composite stretchable part 4 is illustrated for the outer packaging material continuous body 2S.

Then, as shown in FIGS. 18 and 19, the elastic member 42 (the waistline elastic member 23 and the waist elastic member 24 correspond to the present manufacturing method) is contracted, and a plurality of sheets are provided on each of the two sheet continuous bodies 21S and 22S. By forming the collar 43, the composite stretchable part 4 forming a part of the waistline gather G1 and a part of the waist gather G2 is obtained in a predetermined region of the outer packaging material continuum 2S. In the region where the extended region 21B of the outer layer sheet 21 exists, the extended region 21B also has a hook shape as shown in FIG.
18 is a cross-sectional view showing the composite stretchable part 4 in a region where the extension region 21B does not exist, and FIG. 19 is a cross-sectional view showing the composite stretchable unit 4 in a region where the extension region 21B exists.

  The leg elastic member cutting region forming part 62C of the composite stretchable part forming roll 62 is a part for cutting the leg elastic member continuous body 25S existing at the position of the crotch part C in the center in the width direction. Can be formed. The leg elastic member cutting region forming part 62C is composed of, for example, a large number of convex parts and cutter blades. According to the leg elastic member cutting region forming portion 62C, the leg elastic members 25, 25 separated in the width direction at the center in the width direction of the crotch C can be obtained by cutting the leg elastic member continuous body 25S.

  By inserting the outer envelope material continuum 2S in which the composite stretchable part 4 and the leg elastic member cutting area 52 are not formed between the composite stretchable part forming roll 62 having the above configuration and the anvil roll 63, a predetermined region is obtained. Thus, an outer packaging material continuum 2S in which the composite stretchable part 4 and the leg elastic member cutting region 52 are formed is obtained.

The pants-type disposable diaper 1 of the above embodiment uses the outer packaging material continuum 2S in which the composite stretchable part 4 and the leg elastic member cutting region 52 are formed, and the subsequent steps are performed in the conventional so-called cross-flow pants type. It can manufacture by performing similarly to each process in the manufacturing method of a disposable diaper.
For example, as shown in FIG. 15, the absorbent main body 3 obtained by cutting the absorbent main body continuous body 3 </ b> S on the outer packaging material continuous body 2 </ b> S is rotated 90 degrees with respect to the flow direction. The parts 15 (see FIG. 4) are joined and fixed intermittently. The absorbent main body 3 is fixed to the outer packaging material continuum 2S while maintaining the extended state of the outer packaging material continuum 2S. In other words, the absorbent main body 3 is fixed while maintaining the outer wrapping material continuous body 2 </ b> S so as not to shrink due to the shrinkage force of the composite stretchable part 4 or the like.

  Next, as shown in FIG. 15, both sides of the outer packaging material continuum 2 </ b> S are folded back so as to cover both ends of the absorbent main body 3, and both sides of the outer packaging material continuum 2 </ b> S are formed at both ends of the absorbent main body 3. Then, the outer packaging material continuum 2S is folded in two with the absorbent main body 3. An adhesive is applied in advance to a predetermined position of the inner side of the region to be the extension region 21B in the outer packaging material continuous body 2S, the inner layer continuous sheet 22S, the absorbent main body 3, and the like.

Moreover, as shown in FIG.15 and FIG.16, the trim 13S for leg opening part formation is removed from the outer packaging material continuous body 2S with a rotary cutter, a laser cutter, etc., and the diaper continuous body 1S is obtained.
Then, the diaper continuous body 1S is folded back in the width direction (longitudinal direction of the disposable diaper 1) and folded in two. Next, after forming the side seal portions 11 and 11 by heat sealing, ultrasonic sealing, high frequency sealing or the like, or simultaneously with the formation of the side seal portions 11 and 11, the side seal portions 11 and 11 are divided into individual diapers. A pants-type disposable diaper 1 can be obtained.

  As a method of intermittently fixing the absorbent main body 3 by 90 degrees and intermittently fixing it on the outer packaging material continuum 2S, for example, a method described in JP-A-4-166150 can be used. Further, the main body joint 15 (see FIG. 4) for fixing the absorbent main body 3 to the outer packaging material continuum 2S may be applied to one or both of the absorbent main body 3 and the outer packaging material continuum 2S. it can. The trim 13S for forming the leg opening can be removed before the absorbent main body 3 is fixed to the outer packaging material continuous body 2S.

  Next, other embodiment of the underpants type disposable diaper of this invention is described. In the other embodiments, differences from the first embodiment described above will be mainly described, and the same points are denoted by the same reference numerals and description thereof will be omitted. For the points that are not particularly described, the description of the first embodiment is applied as appropriate. In other embodiments, the same effects as those of the first embodiment can be obtained.

  As shown in FIGS. 20 and 21, the pants-type disposable diaper according to the second embodiment is different in the configuration of the waist gather G2 from the first embodiment. FIG. 20 is a developed plan view showing the application position of the adhesive on the outer layer sheet 21 in the second embodiment. In FIG. 20, only the waist elastic member 24 among the elastic members in the outer packaging material 2 is illustrated. FIG. 21 is a developed plan view showing the application position of the adhesive on the inner layer sheet 22 in the second embodiment.

Specifically, in the second embodiment, as shown in FIGS. 20 and 21, the waist elastic member 24 is in an extended state at the center in the width direction of the waist portion F, and the outer layer sheet 21 and / or the inner layer sheet. 22 is fixed with an adhesive Q. In the region where the waist elastic member 24 is fixed to the outer layer sheet 21 and / or the inner layer sheet 22 with the adhesive Q at the center in the width direction of the waist part F (hereinafter also referred to as “high rigidity region”), the adhesive Q is Although it may be coated in a planar shape, it is intermittently (partially) coated only in the vicinity of the waist elastic member 24 from the viewpoint of ensuring the breathability and softness of the waist portion F as much as possible. It is preferable.
The waist elastic member 24 is preferably fixed to both the outer layer sheet 21 and the inner layer sheet 22, but may be fixed only to the outer layer sheet 21 or only to the inner layer sheet 22.
Other configurations are the same as those in the first embodiment.

  According to the disposable diaper of 2nd Embodiment which has a highly rigid area | region in the width direction center part of the waist part F, although the air permeability of the waist part F and softness fall a little, it originates in the rigidity of a highly rigid area | region. The rigidity of the entire part F is also improved. For this reason, at the time of wearing, the peripheral portion of the waist portion F is not easily turned up and folded, and thus the waist portion F is not easily displaced.

The configuration of the composite stretchable portion 4 is not limited to the configuration of the composite stretchable portion 4 shown in FIGS. 12 and 17. For example, the joint portions 41 may be arranged in a staggered manner as shown in FIG. That is, an array pattern in which the positions of the joint portions 41 are shifted by a half pitch (P1 / 2) between the row in the stretch direction (X direction) of the composite stretchable portion 4 and the row adjacent thereto.
More specifically, the joint portion 41 is formed so as to form a line (form a seal line) in the expansion / contraction direction (X direction) of the composite expansion / contraction portion 4 and the direction orthogonal to the expansion direction (Y direction). One joining portion 41 forming a row in the direction (Y direction) is formed for every two elastic members.
Between the column in the expansion / contraction direction (X direction) of the composite stretchable portion 4 and the row adjacent thereto, a region where the joint portion 41 does not exist is continuously formed between both end portions 44 of the composite stretchable portion 4. The elastic member 42 is arranged in a non-bonded state in the region. As a result, two ridges 43 are formed between the joint portions 41 and 41 adjacent to each other in the stretching direction (X direction) of the composite stretchable portion 4.

  From the viewpoint of reliably forming the flange 43 extending continuously over the plurality of elastic members 42, in the stretched state of the composite stretchable portion 4 (the state shown in FIG. 22), the stretchable direction (X The pitch P1 (see FIG. 22) of the joints 41 in the direction) is preferably 1 to 30 mm, particularly 6 to 20 mm, and the length L1 (see FIG. 22) of each joint 41 is 0.1. It is preferably ˜5 mm, particularly preferably 0.2 to 1.5 mm. The ratio (P1 / L1) between the pitch P1 and the length L1 is preferably 1.1 to 300, particularly 4 to 100.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment.
For example, the composite stretchable part 4 can be applied to gathers other than the waistline gather G1 and the waist gather G2 (for example, the leg gather G3 and the front crotch gather G4). When the leg gather G3 and / or the front crotch gather G4 is formed from the composite stretchable part 4 (an example of the gathering position is indicated by the symbol “C1” in FIG. 13), the composite stretchable part 4 in the waistline gather G1 It is preferable that the collar 43 and the collar 43 of the composite stretchable part 4 in the leg gather G3 and / or the front crotch gather G4 are continuous along the longitudinal direction of the outer packaging material.

The composite stretchable part 4 that forms the waistline gather G1 may be provided only in a region outward in the width direction from the absorbent main body 3.
The outer packaging material 2 is formed of a laminated body of an outer layer sheet 21 having the same shape as the outer packaging material 2 and a separated inner layer sheet 22 that exists only in the abdominal side A and the back side B and does not exist in the crotch C. May be. In the outer packaging material 2 having this configuration, the crotch portion C is formed only from the outer layer sheet 21.

  The flange 43 in the composite stretchable part 4 in the above embodiment is continuous across the two elastic members 42 located at both ends in the direction (Y direction) orthogonal to the stretchable direction of the composite stretchable part 4. The elastic member 42 located in the vicinity of the end in the Y direction of the stretchable part 4 may exist in a state of being joined to the outer layer sheet 21 and the inner layer sheet 22. However, it is preferable that the flange 43 is continuous over at least three, preferably half, particularly preferably 70% or more, of the total number of the elastic members 42. Further, the end portion of the elastic member 42 joined to both the sheets 21 and 22 may be present inside the end portion 44 of the composite stretchable portion 4 in the stretchable direction (X direction).

Although the number of the elastic members 42 in the composite stretchable part 4 can be appropriately determined according to the size and use of the composite stretchable part 4, it can be set to 5 to 30, for example. Further, the joining portion 41 can be formed by joining with an adhesive such as ultrasonic joining or hot-melt adhesive other than heat fusion.
Further, the arrangement pattern of the joint portions 41 can be changed as appropriate. The shape of the joint portion 41 can be an appropriate shape such as a rectangular shape, an oval shape, a circular shape, or a rhombus shape.

FIG. 1 is a perspective view showing a first embodiment of a pants-type disposable diaper according to the present invention. FIG. 2 is a plan view showing a state in which the disposable diaper shown in FIG. 1 is developed and extended. FIG. 3 is an exploded perspective view of the disposable diaper shown in FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a view showing the absorbent core in the disposable diaper shown in FIG. 1, (a) is a plan view, (b) is a BB cross-sectional view shown in (a), and (c) is C shown in (a). It is -C sectional drawing. FIG. 6 is a developed plan view of the outer packaging material viewed from the inner surface side of the outer layer sheet in a state where the inner layer sheet is virtually removed. FIG. 7 is a developed plan view showing the application position of the adhesive on the outer layer sheet. FIG. 8 is a developed plan view showing the application position of the adhesive in the inner layer sheet. FIG. 9 is an explanatory view showing the iliac bone. FIG. 10 is an explanatory diagram showing a method for calculating the slip-off force at the wearer's waist. FIG. 11 is an explanatory diagram showing a method for measuring the length of the superior anterior iliac spine height. FIG. 12 is a plan view showing the composite stretchable part in an extended state. FIG. 13 is a schematic front view showing the density of wrinkles in a gather composed of composite stretchable parts. FIG. 14 is a graph obtained by measuring the temperature and humidity of the space between the wearer's skin and the diaper. FIG. 15 is a perspective view showing the entire contents of one manufacturing method of the pants-type disposable diaper shown in FIG. FIG. 16 is a conceptual diagram centering on the process of forming the composite stretchable part and the leg elastic member cutting region in the manufacturing method of the pants-type disposable diaper shown in FIG. 15. FIG. 17 is a conceptual diagram centering on the step of forming the composite stretchable part in the method for manufacturing the pants-type disposable diaper shown in FIG. 15. 18A and 18B are partial enlarged views of a longitudinal section of the composite stretchable part, where FIG. 18A is a diagram showing an extended state, and FIG. FIG. 19 is a partially enlarged view of another longitudinal section of the composite stretchable portion, where (a) shows a stretched state, and (b) shows a state in which wrinkles are formed and wrinkles are formed. FIG. 20 is a developed plan view showing the application position of the adhesive on the outer layer sheet in the second embodiment (corresponding to FIG. 7). FIG. 21 is a developed plan view showing the application position of the adhesive on the inner layer sheet in the second embodiment (corresponding to FIG. 8). FIG. 22 is a plan view (corresponding to FIG. 12) showing another form of the composite stretchable part in an expanded state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 11 Side seal part 12 Waist opening part 13 Leg opening part 2 Outer packaging material 2A The width direction center part of outer packaging material 2B The width direction outer side part of outer packaging material 21 Outer layer sheet 21A Non-extending area | region 21B Extension area 22 Inner layer Sheet 23 Girth elastic member 24 Waist elastic member 25 Leg elastic member 26 Front crotch elastic member 3 Absorbent main body 32 Top sheet 33 Back sheet 34 Absorbent core 35 Side cuff 36 Side cuff elastic member 37 Side cuff forming sheet 4 Composite elastic part 41 Joint part 42 Elastic member 43 44 End 52 Leg elastic member cutting area 61 Nip roll 62 Composite elastic part forming roll 62A Composite elastic part forming part 62C Leg elastic member cutting area forming part 63 Anvil roll 64 Adhesive coating Device 65 Swing guide G1 Girth gather G West Gather G3 Leg Gather G4 Front Crotch Gather 1S Diaper Continuum 13S Trim 2S Outer Packaging Continuous 21S Outer Sheet Continuous 22S Inner Sheet Continuous 3S Absorbent Main Body Continuous A Abdominal Side B Back Side C Inseam D Torso D1 Upper waistline D2 Lower waistline E Front crotch F Waist

Claims (3)

It has 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 the outer packaging material is divided into the abdominal side, crotch part and back side part in the longitudinal direction. The pants-type disposable diaper in which the side edges of the abdomen and back sides of the outer packaging material are joined together to form a pair of side seals, a waist opening and a pair of leg openings,
The longitudinal end of the absorbent main body recedes inward in the longitudinal direction from the longitudinal end of the outer packaging material,
The outer packaging material is formed from an outer layer sheet, an inner layer sheet, and a plurality of elastic members disposed between both sheets,
The waistline and waist gathers on the abdomen and back sides of the outer packaging material are provided with waistline gathers and waist gathers, respectively, by arranging the elastic members over the entire circumference.
The waistline gather is formed from the composite stretchable part at least in the widthwise outer side of the waistline part, and the waist gather is formed from the composite stretchable part at least in the widthwise outside part of the waist part,
In the composite stretchable part, the outer layer sheet and the inner layer sheet are joined to each other by an intermittent joint in the stretchable direction of the composite stretchable part and the direction orthogonal thereto, and the elastic member is arranged so as not to pass through the joint. The outer layer sheet and the inner layer sheet are not fixed to the outer layer sheet and the inner layer sheet in the portion excluding both ends, and each of the outer layer sheet and the inner layer sheet is formed by forming a plurality of ridges extending continuously over a plurality of elastic members. Has been
The plurality of ridges extend from the outer end portion of the waist portion to the inner end portion of the waistline portion along the longitudinal direction of the outer packaging material in the widthwise outer side portion of the waist portion and the widthwise outer side portion of the waistline portion. Pants-type disposable diapers.   The pants-type disposable diaper according to claim 1, wherein the waist gather is formed from the composite stretchable part over the entire circumference of the waist part.   2. The pants-type disposable diaper according to claim 1, wherein the elastic member is fixed to the outer layer sheet and / or the inner layer sheet with an adhesive at a central portion in the width direction of the waist portion.

Images