JP2008131968A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article with waist gathers gently touching the abdomen of a user so that the rubber marks are hardly left. <P>SOLUTION: The absorbent article comprises an absorbent body 3 and an external wrapping material 2. The external wrapping material 2 is divided into an abdomen-side part A, a crotch part C and a back-side part B. The external wrapping material 2 comprises an outer layer sheet 21, an inter layer sheet 22 and elastic members 23-26. In a girth part D of the external wrapping material 2, girth gathers made of a composite stretch part are formed. In the composite stretch part, the outer layer sheet 21 and the inner layer sheet 22 are jointed to each other with intermittent joint parts in the direction of extension/contraction and the orthogonally crossing direction of the composite stretch part, and the elastic member 23 is disposed not to pass the joint parts. The composite stretch part is not secured to the outer layer sheet 21 or the inner layer sheet 22 except in either end of the elastic member 23. A plurality of gathers, continuously extending over the elastic member 23, are formed of the outer layer sheet 21 and the inner layer sheet 22. In a waistline part F, the stretch rate at the center in the cross direction of the external wrapping material 2 is lower than the stretch rate in the outer side in the cross direction of the external wrapping material 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to absorbent articles such as disposable diapers and sanitary napkins.

  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 from an outer layer sheet, an inner 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 outer layer sheet and the inner layer sheet at the portion and the waist portion.

JP 2004-89403 A

However, in the pants-type disposable diaper described in Patent Document 1, the waistline gather and the waist gather are formed by joining elastic members to the outer layer sheet and the inner 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 number of elastic members 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, it is desired that the waist gather more gently hits around the infant's stomach and is less likely to have rubber marks. This also applies to other absorbent articles such as unfolded disposable diapers and pants-type sanitary napkins.

  Accordingly, an object of the present invention is to provide an absorbent article having a waistline gather and a waist gather at the waistline part and the waist part, which is excellent in air permeability and softness of the waistline part and the waist part, and contraction of elastic members of the waistline gather and the waist gathers. To provide an absorbent article that can fully utilize the force, is excellent in cushioning in the thickness direction of the waist gathers and waist gathers, and that the waist gathers hit the infant's stomach more gently and is less likely to have rubber marks is there.

  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. The absorbent article is divided, and the outer packaging material includes an outer layer sheet, an inner layer sheet, and a plurality of elastic members disposed between the two sheets, and a waist portion at the ventral side portion and the back side portion of the outer packaging material. And the waist part are respectively provided with a waistline gather and a waist gather formed from a composite stretchable part, and the composite stretchable part is intermittent in the stretchable direction of the composite stretchable part and the direction perpendicular thereto. The elastic members are arranged so as not to pass through the joints, and are not fixed to the outer layer sheet and the inner layer sheet except for both ends of the elastic members. Each of the sheets is formed by forming a plurality of ridges extending continuously over a plurality of elastic members, and the waist portion has an elongation rate at the center in the width direction of the outer packaging material, and the width of the outer packaging material. The said objective is achieved by providing the absorbent article which is lower than the elongation rate in a direction outer side part.

  According to the absorbent article of the present invention, in the absorbent article having the waistline gather and the waist gather at the waistline part and the waist part, respectively, the breathableness and softness of the waistline part and the waist part are excellent, and the elasticity of the waistline gather and the waist gathers. The contraction force of the member can be fully utilized, and the cushioning properties in the thickness direction of the waistline gather and the waist gather are excellent. Moreover, the waist gathers hit the infant's stomach more gently, making it less likely to leave rubber marks.

Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on a pants-type disposable diaper which is a preferred embodiment thereof. In the following description of the embodiment, when referring to “disposable diapers” or “diapers”, they are substantially synonymous with the “absorbent article” of the present invention.
As shown in FIGS. 1 to 4, the pants-type disposable diaper 1 of the present embodiment includes an absorbent main body 3 including an absorbent core 34 and an outer packaging material 2 joined to the non-skin contact surface side of the absorbent main body 3. 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 2 are joined together. It is a pants-type disposable diaper in which a pair of side seal parts 11, a waist opening part 12, and a pair of leg opening parts 13 are formed.

  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, 26 disposed between both sheets 21, 22. The waistline portion D and the waist portion F in the A and back side portions B are respectively provided with a waistline gather G1 and a waist gather G2 formed from the composite stretchable portion 4 (see FIG. 16).

  Specifically, the disposable diaper 1 according to 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 includes almost the entire region corresponding to the side seal portion 11, the region corresponding to the non-functionalized region 51 (described later) of the waistline elastic member 23, and the leg elastic member cutting region 52 (described later). ) Is applied to the area corresponding to.
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 in 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 shifted (not shown), the range of the waist portion F is determined on the assumption that there is no shifted and extended region.

  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. A composite stretchable part 4 (details will be described later) is formed mainly of the outer layer sheet 21, the inner layer sheet 22 and the waist elastic member 24. The composite stretchable part 4 extends between the pair of side seal parts 11. A waist gather G2 is formed (over the entire circumference of the waist portion F).

  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 plurality of members disposed over half of the peripheral edge of the leg opening 13 near the ventral side A in relation to the manufacturing method described later. In addition, by combining a plurality of members disposed over the half near the back side portion B, it is disposed so as to cover the entire periphery of the leg opening 13, but depending on the manufacturing method, One leg elastic member 25 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 vicinity of the side edge of the absorbent main body 3 and the side seal portion 11, and is not disposed between the vicinity of the side edge of the absorbent main body 3.

And the composite elastic part 4 is formed mainly by the outer layer sheet 21, the inner layer sheet 22, and the waistline elastic member 23. By this composite elastic part 4, the vicinity of the side edge part of the absorbent main body 3 and the side seal part 11 are formed. A pair of waistline gathers G1 arranged in the width direction is formed in the width direction. The waistline gather G1 is not disposed between the side edge portions of the absorbent main body 3.
The “near side edge of the absorbent main body 3” refers to a region within 30 mm inward in the width direction and within 20 mm outward in the width direction from the side edge of the absorbent main body 3.

  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 (not shown), they are shifted and extended. A diaper longitudinal center line CL is defined on the assumption that there is no region.

  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 non-functionalized region 51 that prevents the elastic member from contracting is formed in a region of the outer packaging material 2 facing the absorbent main body 3. The non-functionalized region 51 in the present embodiment is formed without expressing the contraction force of the waistline elastic member 23 and the front crotch elastic member 26. As described in detail in the description of the manufacturing method described later, the non-functionalized region 51 is a continuous body 23S of the waistline elastic member 23 and the front crotch elastic that are disposed across the entire width direction of the outer packaging material 2 in the raw material state. The continuous body 26S of the member 26 is a region formed without partially expressing the contraction force. In order to prevent the contraction force from appearing, for example, a large number of convex portions and cutter blades that divide the elastic member, a large number of emboss pins that harden the elastic member by heat sealing, and the like are used.

By forming the non-functionalized region 51, a pair of separated in the width direction from the waistline elastic member continuous body 23 </ b> S and the front crotch elastic member continuous body 26 </ b> S disposed over the entire width direction of the outer packaging material 2. A waistline gather G1 and a front crotch gather G4 are formed.
The non-functionalized region 51 located between the pair of waistline gathers G1 in the width direction is formed without causing the contraction force to be exerted on the waistline elastic member continuous body 23S joined to the outer layer sheet 21 and the inner layer sheet 22. On the other hand, the non-functionalized region 51 located between the pair of front crotch gathers G4 in the width direction is the front crotch elastic member continuous body 26S joined to the outer layer sheet 21 and the inner layer sheet 22. It is formed without developing the contractile force. Thereby, shrinkage | contraction of the absorptive main body 3 can be prevented, and the favorable external appearance and absorption performance of the absorptive main body 3 can be implement | achieved.

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. Thereby, the urine excreted in front of the absorbent main body 3 can be smoothly transferred to the rear, and the absorption performance is remarkably improved.
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 16, the composite stretchable part 4 has 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.

  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 70% (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 16, 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) orthogonal 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 end portions 44 of the composite stretchable portion 4 differ depending on the gathers formed thereby. In the embodiment shown in FIG. 1, both end portions 44 of the composite stretchable part 4 that forms the waistline gather G1 are the vicinity of the side edge of the absorbent main body 3 and the side seal part 11, and the composite stretchable part that forms the waist gather G2. Both end portions 44 of the portion 4 are both side seal portions 11, 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 of the stretchable direction (X direction) of the composite stretchable part 4 and the direction (Y direction) perpendicular thereto. Based on.
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, a single layer made of air-through nonwoven fabric, heat roll nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, etc. from the viewpoint of forming a flexible ridge 43 having a beautiful appearance and good touch. It is preferably a sheet or a laminated sheet. In particular, an air-through nonwoven fabric is preferable from the viewpoint of the touch (softness).

  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 in the measurement environment of 20 ° C. and 65% RH under the measurement conditions of a compression speed of 10 mm / min and a measurement distance of 20 mm by the compression test mode of the Tensilon universal testing apparatus. 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 expansion ratio and tensile load of the elastic member 42. In order to make the cross-sectional shape of the flange 43 convex, the required expansion ratio and tensile load of the elastic member 42 are required. The expansion magnification here is obtained from the following equation, where A (mm) is the length when not stretched and B (mm) is the length when stretched.
Elongation magnification (%) = (B / A) × 100

  The elastic member 42 is preferably bonded to the outer layer sheet 21 and the inner layer sheet 22 in a stretched state of 120 to 1100%, particularly preferably 150 to 500%. 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 load at the time of 200% elongation with 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 200% or more, particularly preferably 300% 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 130 to 600%.

Next, the expansion ratio of the waist part F will be described. In the absorbent article of the present invention, 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 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 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 500%, more preferably 150 to 400%. The elongation ratio of the width direction outer side part 2B of the waist part F is preferably 150 to 600%, more preferably 200 to 500%. 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 30 to 200%, more preferably 50 to 150%.

  Next, the tensile load of the waist part F will be described. The waist portion F preferably has a load (tensile load) of 20 gf or more, and more preferably 25 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 circumferential length of the waist portion F is extended to 300 mm is less than 20 gf, the waist portion F cannot be fully shrunk and looks bad.

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 circumferential length of the waist portion F is extended to 500 mm is more than 200 gf, it is not preferable because it causes a rubber mark to be attached at the time of mounting and also causes a slip-off as described above.
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”. The “peripheral length” here refers to a peripheral length in a ring-like state in which the side seal portions 11 are connected, and particularly refers to an inner peripheral length.

Further, when the tensile loads of the waist part F, the upper waistline part D1 and the lower waistline part D2 are compared, the tensile load of the upper waistline part D1 is the highest, and then the tensile load of the lower waistline part D2 is high, and the waist part F 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. The comparison of the tensile load of each site | part is performed with the sample which has the same width | variety (preferably 30 mm) along the longitudinal direction of an absorbent article.
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 circumference of the waist opening when the pair of side seal portions 11, 11 are extended in the width direction to a load of 2400 gf is preferably 660 mm or more, and more preferably 680 mm or more. “The circumference of the waist opening 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 gripped by holding the pair of side seal portions 11 and 11. The inner circumference is the length when the extension load reaches 2400 gf by gradually extending in the width direction.
Here, the reason why the load of 2400 gf is defined is that the size of the maximum load by which the mother can spread the diaper in the width direction is generally about 2400 gf, and the relationship of the circumference of the waist opening at this time Corresponds to the superiority or inferiority of “ease of extension (ease of extension)” when the mother expands the diaper.

  The energy required for stretching the waist opening of the pant-type absorbent article is preferably 4 N · m or less, and more preferably 3.5 N · m or less. If the energy required for stretching the waist opening 12 is more than 4 N · m, it is difficult for the mother to expand the diaper in the width direction, and the mother does not feel that it is easy to expand. The smaller the energy, the easier the diaper is stretched in the width direction.

  The energy required for extending the width between the pair of side seal portions 11, 11 in the width direction to extend the circumference of the waist opening 12 to 600 mm is preferably 2 N · m or less, and 1.8 N -More preferably, it is m or less. Here, the reason why the circumference of 600 mm is defined is that the circumference of the diaper when the mother puts the diaper on the child is about 600 mm, and therefore the circumference of the waist opening 12 is extended to 600 mm. The energy required for this is an index representing “easy to put on” when the mother wears a diaper on the child. If this value is 2 N · m or less, the mother feels it is significantly easier to wear.

The energy required for extending the waist opening of the pant-type absorbent article is measured by the following method.
[Measurement method of energy required for stretching waist opening of pant-type absorbent article]
(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 diaper width direction until the load reaches 2400 gf or the peripheral length reaches 600 mm.
(4) From the area of the SS curve (load-strain curve) obtained at that time, the energy required for expansion of the waist opening 12 is obtained.

  According to the pants-type disposable diaper of the present embodiment having the above-described configuration, the waistline gather G1 and the waist gather G2 are formed from the composite stretchable part 4, and the gather can be obtained without substantially using the hot melt adhesive. Therefore, the air permeability in the ventral side A and the back side B is excellent. 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 load difference between the characteristic curve at the time of expansion and the characteristic curve at the time of contraction is small, i.e., the load fluctuation with respect to the fluctuation of the circumference is small, and an equivalent wearing pressure can be obtained for both small and large infants It can be seen that problems such as diaper slippage for relatively small children and rubber marks on relatively large children are eliminated, and the size application range of the wearer is increased.

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, in the waist portion F, the elongation rate at the center portion 2 </ b> A in the width direction of the outer packaging material 2 is lower than the elongation rate at the outer side portion 2 </ b> B in the width direction of the outer packaging material 2. For this reason, the waist portion F easily expands in the central portion in the width direction around the stomach where the variation in the abdominal position is large, while the waist portion F is not so large in the width direction outer portion around the stomach. Does not stretch. For this reason, the waist gather G2 gently hits the infant's stomach and is less likely to have rubber marks.

  Furthermore, due to the difference in the above-described elongation rate in the waist portion F, the density of the heels of the waist gather G2 in the width direction central portion 2A (the number of ridges per unit length along the width direction of the outer packaging material 2) is It becomes smaller than the density of the wrinkles of the waist gathers G2 in the width direction outer side part 2B. Usually, since the width of the width direction center portion 2A and the width of the width direction outer portion 2B are not significantly different, the number of wrinkles in the width direction center portion 2A is smaller than the number of wrinkles in the width direction outer portion 2B. Therefore, there is also an advantage that printing is easily performed on the central portion 2A in the width direction.

  Moreover, since the load when the circumference of the waist part F is extended to 300 mm is 20 gf or more, it is excellent in appearance. On the other hand, since the load when the circumferential length of the waist part F is extended to 500 mm is 200 gf or less, it gently hits around the stomach where the change in the abdominal position is large, and rubber marks can be prevented. In this way, it is possible to improve the appearance and reduce the load.

  Furthermore, since the circumference of the waist part F when extending between the pair of side seal parts 11, 11 in the width direction up to a load of 2400 gf is 660 mm or more, the mother can easily expand the diaper 1 in the width direction. So you can easily put on a diaper.

  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. 14 is a perspective view showing the entire manufacturing method. FIG. 15 is a conceptual diagram showing mainly the steps of forming the composite stretchable part, the non-functionalized region, and the leg elastic member cutting region in the present manufacturing method. FIG. 16 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 FIGS. 14 to 16, the outer layer sheet 21 and the inner layer sheet 22 are joined by the joining portion 41 to form the composite stretchable portion 4, and the contraction force of the elastic members 23 and 26 is applied. The same roll 62 is used for the step of forming the non-functionalized region 51 without making it appear.
In this manufacturing method, as shown in FIG. 14, 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. 15, 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 FIG. 7 and FIG. 8 are applied to the respective facing surfaces by the adhesive coating device 64 (see FIG. 15). The hot melt adhesive Q is applied to the surface. Further, the continuum 25S of the leg elastic member 25 is swung along the shape of the leg opening 13 by the swing guide 65 (see FIG. 15), while the outer layer sheet continuum 21S and the inner layer sheet continuum 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 a region between the side edge portion of the absorbent main body 3 and the side seal portion 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, the non-functionalized region 51, 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 stretchable part forming roll 62 includes a composite stretchable part forming part 62A that forms the composite stretchable part 4 on its peripheral surface, and a non-functionalized region forming part 62B that forms the nonfunctionalized region 51 and leg elastic member cutting. A leg elastic member cutting region forming part 62 </ b> C that forms the region 52 is provided.
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. 16) 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 is provided. 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. 16 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. 17 and 18, the elastic member 42 (the waistline elastic member 23 and the waist elastic member 24 are applicable in the present manufacturing method) is shrunk to provide a plurality of sheets on each of the two sheet continuous bodies 21S and 22S. By forming the collar 43, the composite stretchable part 4 that forms the waistline gather G1 and the waist gather G2 is obtained in a predetermined region of the outer packaging material continuous body 2S. In the region where the extension region 21B of the outer layer sheet 21 exists, the extension region 21B also has a hook shape as shown in FIG.
FIG. 17 is a cross-sectional view showing the composite stretchable part 4 in the region where the extension region 21B does not exist, and FIG. 18 is a cross-sectional view showing the composite stretchable part 4 in the region where the extension region 21B exists.

  The non-functionalized region forming part 62B of the composite stretchable part forming roll 62 is a part that prevents the contractive force of the elastic member from being expressed, and can form the non-functionalized region 51 in the outer packaging material continuous body 2S. The non-functionalized region forming part 62B is composed of a large number of convex portions and cutter blades that divide the elastic member, and a large number of emboss pins that harden the elastic member by heat sealing.

  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.

  Between the composite stretchable part forming roll 62 having the above configuration and the anvil roll 63, the outer envelope material continuous body 2S in which the composite stretchable part 4, the non-functionalized area 51, and the leg elastic member cutting area 52 are not formed is inserted. By doing so, the outer packaging material continuous body 2S in which the composite stretchable part 4, the non-functionalized region 51, and the leg elastic member cutting region 52 are formed in a predetermined region 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, the non-functionalized region 51, and the leg elastic member cutting region 52 are formed. It can manufacture by performing similarly to each process in the manufacturing method of what is called a cross-flow type underpants type disposable diaper.
For example, as shown in FIG. 14, after the absorbent main body 3 obtained by cutting the absorbent main body continuous body 3S on the outer packaging material continuous body 2S is rotated by 90 degrees with respect to the flow direction, the main body bonding is performed. 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. 14, 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.14 and FIG.15, 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.

  According to this manufacturing method, the outer layer sheet 21 and the inner layer sheet 22 are joined by the joining part 41 to form the composite stretchable part 4, and the contraction force of the elastic members 23 and 26 is not expressed and the non-functionalized region Since the process of forming 51 is performed using the same roll 62, the underpants type disposable diaper provided with the composite expansion-contraction part 4 and the non-functionalization area | region 51 can be produced efficiently.

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 16. 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 state where the composite stretchable portion 4 is extended (the state shown in FIG. 19), the stretch direction (X The pitch P1 (see FIG. 19) of the joint portions 41 in the direction) is preferably 1 to 30 mm, particularly 6 to 20 mm, and the length L1 (see FIG. 19) of each joint portion 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 a gather other than the waistline gather G1 and the waist gather G2.
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 outer layer sheet 21 is composed of a sheet that forms the ventral side A, a sheet that forms the crotch C, and a sheet that forms the back side B, which are separate sheets, and these sheets are arranged in the longitudinal direction of the outer layer sheet 21. It can also be formed by connecting. The same applies to the inner layer sheet 22.

  Although the said embodiment is a pants type disposable diaper, this invention is not restrict | limited to this and can be applied to a deployment type disposable diaper. Further, the present invention is not limited to disposable diapers, and can be applied to a pants-type (shorts-type) sanitary napkin or the like.

  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 pants-type disposable diaper which is an embodiment of the absorbent article of the present invention. FIG. 2 is a plan view showing a state in which the pants-type disposable diaper shown in FIG. 1 is developed and extended. FIG. 3 is an exploded perspective view of the pants-type disposable diaper shown in FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a view showing an absorbent core in the pants-type disposable diaper shown in FIG. 1, wherein (a) is a plan view, (b) is a cross-sectional view along BB shown in (a), and (c) is (a). It is CC sectional drawing shown in FIG. 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 perspective view showing the entire contents of one manufacturing method of the pants-type disposable diaper shown in FIG. 1. FIG. 15 is a conceptual diagram centering on the steps of forming the composite stretchable part, the non-functionalized region, and the leg elastic member cutting region in the manufacturing method of the pants-type disposable diaper shown in FIG. 14. FIG. 16 is a conceptual diagram centering on the step of forming the composite stretchable part of the method for manufacturing the pants-type disposable diaper shown in FIG. 14. FIGS. 17A and 17B are partially enlarged views of the longitudinal section of the composite stretchable portion, where FIG. 17A is a diagram illustrating an expanded state, and FIG. FIGS. 18A and 18B are partially enlarged views of another vertical section of the composite stretchable portion, where FIG. 18A is a diagram showing an extended state, and FIG. 18B is a diagram showing a state in which a fold is contracted. FIG. 19 is a plan view (corresponding to FIG. 12) showing another form of the composite stretchable part in an expanded state.

Explanation of symbols

1 Pants-type disposable diaper (absorbent article)
DESCRIPTION OF SYMBOLS 11 Side seal part 12 Waist opening part 13 Leg opening part 2 Outer packaging material 2A The width direction center part of the outer packaging material 2B The width direction outer side part of outer packaging material 21 Outer layer sheet 21A Non-extension area | region 21B Extension area | region 22 Inner layer sheet | seat 23 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 Joining Part 42 elastic member 43 ４４ 44 end part 51 non-functionalized area 52 leg elastic member cutting area 61 nip roll 62 composite stretchable part forming roll 62A composite stretchable part forming part 62B nonfunctionalized area forming part 62C leg elastic member cutting area forming part 63 Anvil roll 64 Adhesive coating device 65 Swing guide G1 Girth Gather G2 Waist Gather G3 Leg Gather G4 Forefoot Gather 1S Diaper Continuous 13S Trim 2S Outer Packaging Continuous 21S Outer Sheet Continuous 22S Inner Sheet Continuous 3S Absorbent Main Body A Abdominal Side B Back Side C Inseam D waistline D1 upper waistline D2 lower waistline E front crotch F waist

Claims (5)

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 a ventral side portion, a crotch portion, and a back side portion in the longitudinal direction. An absorbent article,
The outer packaging material includes an outer layer sheet, an inner layer sheet, and a plurality of elastic members disposed between both sheets,
A waistline gather and waist gathers formed from a composite stretchable part are respectively provided in the waistline part and the waist part in the abdomen and back sides of the outer packaging material,
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 waist part is an absorbent article in which the elongation rate at the widthwise central portion of the outer packaging material is lower than the elongation rate at the widthwise outer side portion of the outer packaging material.   The both sides of the abdomen and the dorsal side of the outer packaging material are joined together to form a pair of side seals, a waist opening, and a pair of leg openings, and the pants are formed. Absorbent articles.   The absorbent article according to claim 2, wherein the waist portion has a load of 20 gf or more when the circumference is extended to 300 mm, and a load when the circumference is extended to 500 mm is 200 gf or less.   The absorptive article according to claim 2 or 3 whose energy required for extension of said waist opening when it is extended in the width direction to a load of 2400gf between a pair of said side seal parts is 4N * m or less.   The absorbent article according to any one of claims 2 to 4, wherein the energy required to extend the circumference of the waist opening to 600 mm is 2 N · m or less.

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