JP6410075B2 - Elastic structure of absorbent articles - Google Patents

Description

  The present invention relates to a stretchable structure of an absorbent article formed by fixing an elongated elastic stretchable member between stretched sheet materials in a stretched state, and in particular, a wrinkle extends straight, looks good, and has excellent breathability However, the present invention relates to a stretchable structure that is also excellent in a feeling of excitement (property of being compressed and restored flexibly in the thickness direction).

  For example, a pants-type disposable diaper includes an exterior body having a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior body, and the front body and the back body of the exterior body are on both sides. Are joined together to form a waist opening and a pair of left and right leg openings.

  In the pants-type disposable diaper, in order to improve the fit to the body, elongated elastic elastic members such as rubber thread are fixed in a stretched state along the circumferential direction at various locations on the exterior body, Forming a stretchable structure, among them, a waist edge elastic elastic member along the width direction at the edge of the waist opening, and a waist lower part along the width direction at the crotch side than the waist edge elastic elastic member A thing provided with an elastic expansion-contraction member has a comparatively high fit with respect to a body, and is used widely.

  On the other hand, the tape-type disposable diaper is a crotch part, an abdominal part extending to the front side of the crotch part, a back side part extending to the rear side of the crotch part, and an absorber provided in a region including the crotch part And a fastening tape that protrudes from both sides of the back portion and a target tape that is located on the outer surface of the abdominal portion and to which the fastening tape is connected. It has a structure which is connected to the target tape by turning from both sides to the outer surface of the abdominal side. Such a tape-type disposable diaper is used not only for infants but also widely used for nursing care (adult use). In general, tape-type disposable diapers are inferior in fit in the waistline direction compared to pants-type disposable diapers, so in order to improve this, slender shapes such as rubber thread along the width direction on the back side and fastening tape These elastic elastic members are fixed in an extended state to form an elastic structure in the trunk direction.

  And as what improves these expansion-contraction structures, as shown in FIG. 12, two sheet | seat materials 12H and 12S are joined in many expansion | extension directions and the longitudinal direction orthogonal to this by joining many sheet | seat junction parts. 70, and a large number of elongated elastic elastic members 19 are arranged between the sheet materials 12H and 12S so as not to pass through the sheet bonding portion 70 (so as to pass through the non-bonding portions). An expansion / contraction structure (see Patent Documents 1 to 3 below, also referred to as a longitudinal intermittent joining form) in which only the portion is fixed to both sheet materials 12H and 12S has been proposed. According to this prior art, the portion where the sheet joint portion 70 is aligned in the vertical direction becomes a groove that is continuous in the vertical direction, and the portion between the grooves becomes a large ridge 80 that bulges on both sides of the front and back sides. In addition to improving the properties, the heel 80 is excellent in a feeling of warmth. Although the code | symbol 75 in FIG. 12 has shown the welding part of the sheet | seat materials 12H and 12S, even if it forms the sheet | seat junction part 70 using an adhesive agent, the shape of the collar 80 will become the same.

  However, this prior art has a problem in that the shape of the ridge is a cloud shape or a wave shape, which looks ugly and looks and is inferior in air permeability.

  On the other hand, it is also known that a large number of sheet joining portions are formed by bonding two sheet materials intermittently in the expansion / contraction direction and in a direction crossing the expansion / contraction direction (see, for example, Patent Document 4 below). It is also referred to as a longitudinal continuous joining form.)

  However, this prior art has a problem that the wrinkles extend straight, looks good, and has excellent air permeability, but is inferior in a feeling of fluffiness (a property of being compressed and restored flexibly in the thickness direction).

JP 2008-295930 A JP 2009-297096 A JP 2009-148447 A JP 2010-22588 A

  Then, the main subject of this invention is providing the expansion-contraction structure which is excellent also in a feeling of hunwari, while a wrinkle extends straightly, looks good, and is excellent in air permeability.

  As a result of earnest research to solve the above-mentioned problems, the following findings (knowledges about the principle and differences described here have not been explored in any of Patent Documents 1 to 4, and in particular, Patent Document 4) Although there is a description about the line spacing of the sheet joint, it is completely unclear what effect the change will have.)

  That is, in the longitudinal intermittent joining mode, as shown in FIG. 12, the elastic stretchable member 19 is not secured to the sheet at the stretchable position corresponding to the sheet joined portion 70 but is secured to the sheet at both ends (not shown). Therefore, even if the heel 80 is brought close by the contraction force of the elastic expansion / contraction member 19, the contraction of the elastic expansion / contraction member 19 directly acts on the sheet joining portion 70 adjacent in the expansion / contraction direction, and the ridge 80 is between them. Is not formed, but acts on the fixing portions at both ends of the elastic elastic member 19, and as a result that the entire sheet material between them is moved in the width direction, the portions other than the sheet joint portion 70 are indirectly free. Swell to form a ridge 80. As a result, even at a position corresponding to the sheet bonding portion 70 in the vertical direction, as shown in FIG. 12B, the interval in the expansion / contraction direction of the sheet bonding portion 70 is widened, and the shape of the flange 80 is rounded. It will be plump. Moreover, as shown in FIG.12 (c), the position where the elastic expansion-contraction member 19 passes is still more rounded, and the shape of the collar 80 becomes round and plump.

  However, in this longitudinal intermittent joining mode, the gap between the flanges 80 becomes small, and the effect of improving the air permeability becomes poor. Moreover, when the shrinkage force of the elastic elastic member 19 acts indirectly as described above to form the collar 80 and the sheet joint portion 70 is intermittently arranged in the vertical direction, As can be seen from the comparison between FIGS. 12B and 12C, the interval between the sheet joining portions 70 periodically changes in the vertical direction, and the bulge shape of the flange 80 in the portion corresponding to the sheet joining portion 70 in the vertical direction In the longitudinal direction, a difference is made in the bulging shape of the ridge 80 in the portion located between the joint portions, and the shape of the ridge 80 becomes a cloud shape or a wave shape that is staggered, and it looks and is inferior in air permeability.

  On the other hand, in the longitudinal continuous joining form, the sheet joining portion is continuous in the longitudinal direction, and the elastic stretch member is fixed to the sheet at the stretch direction position corresponding to the sheet joining portion, and therefore corresponds to the sheet joining portion in the longitudinal direction. Even if it is a position where the elastic expansion / contraction member passes, the distance between the sheet joining portions in the expansion / contraction direction is uniform, and the wrinkles extend straight, look good, and have excellent air permeability.

  However, since the elastic elastic member is fixed to the sheet at the position in the expansion / contraction direction corresponding to the sheet bonding portion, the contraction of the elastic expansion / contraction member directly acts on the sheet bonding portions adjacent to each other in the expansion / contraction direction. As a result, the distance between the joint portions of the sheet becomes very narrow, the shape of the ridge is thin, and the tip is relatively sharp. Therefore, since the wrinkles are easy to fall and have a thin shape, the feeling of fun is scarce.

  That is, since the longitudinal continuous joining form is completely different from the intermittent joining form in terms of the shape of the ridges, the formation principle is completely different. Then, the present inventor has further studied based on these findings and made the present invention. That is, the present invention that has solved the above problems is as follows.

<Invention of Claim 1>
Between the 1st sheet material, the 2nd sheet material which counters one side of this 1st sheet material, and these 1st sheet materials and the 2nd sheet material, an interval of 10 mm or less is mutually established along an expansion-contraction direction. A plurality of elongated elastic elastic members provided in a space;
Each of the first sheet material and the second sheet material has a thickness of 0.1 to 1 mm, a basis weight of 10 to 20 g / m ² , a bending resistance of 40 to 55 mm in the expansion / contraction direction, and a bending / softening direction orthogonal to the expansion / contraction direction. The degree of bending is 25 to 35 mm, and the bending resistance in the expansion / contraction direction is higher than the bending resistance in the direction orthogonal to the expansion / contraction direction,
The first sheet material and the second sheet material are arranged intermittently in the expansion / contraction direction, continuously in a direction intersecting with the expansion / contraction direction without having a portion that is not joined in either the expansion / contraction direction or the intersecting direction. And joined by an adhesive that intersects the plurality of elongated elastic stretch members, a continuous sheet joint is formed,
The elastic elastic member is fixed to at least one of the first sheet material and the second sheet material by an adhesive at a position intersecting the continuous sheet joining portion ;
The first sheet material and the second sheet material contract as the elastic expansion and contraction member contracts, so that the portions located between the continuous sheet joints in the first sheet material and the second sheet material swell in opposite directions. Each has a ridge,
The stretch rate of the elastic stretch member in a state where the stretch structure is fully deployed is 200 to 350%,
Expansion and contraction direction of the width of each successive sheet joined portion is 1 to 4 mm, the interval of the continuous sheet joints adjacent is 4 to 8 mm,
The first sheet material and the second sheet material are a nonwoven fabric of polypropylene or a copolymer thereof, or a nonwoven fabric of core-sheath fibers having polyethylene as a sheath and polypropylene as a core component,
An elastic structure of an absorbent article characterized by the above.

(Function and effect)
The present invention is based on the longitudinal continuous joining form, and combines the distance between adjacent continuous sheet joining portions and the width in the expansion / contraction direction of each continuous sheet joining portion within a specific range, and has a sufficient height while it should extend straight. It has a feature that makes it difficult to fall down. In the present invention, the width in the expansion / contraction direction of each continuous sheet bonding portion affects the interval between adjacent wrinkles, and this width is 4 mm when the wrinkles to be formed are thin as in the case of longitudinal continuous bonding. If it exceeds, the space between adjacent ridges will become too wide, and not only will individual ridges look independent, but also when the folds will collapse or collapse due to the compressive force in the thickness direction, the adjacent ridges will support As a result of the weakening of the matching action, the resistance to deformation or the restoration after the change is also weakened, and as a result, the sense of fun is insufficient.

Moreover, when the width of the continuous sheet joining portion in the expansion / contraction direction is simply set to 1 to 4 mm and the interval between adjacent continuous sheet joining portions is less than 4 mm or more than 8 mm, the following occurs. That is, the interval between adjacent continuous sheet joints affects the height and width of the ridges, and if the interval between adjacent continuous sheet joints is about 2 mm, the longitudinal direction is the same as in the case of continuous joining in the stretching direction. The ridges are poor in continuity (there is no need to intermittently provide continuous sheet joints in the expansion and contraction direction). At 3 mm, the ridges extend straight in the direction orthogonal to the expansion and contraction direction, but the adjacent ridges support each other. Cannot be expected, and the feeling of fun is not enough. Moreover, when the space | interval of a continuous sheet junction part exceeds 8 mm, a wrinkle will be crushed irregularly by the compression at the time of packaging, and the appearance of a product will worsen. On the other hand, when the width of the continuous sheet joined portion in the expansion / contraction direction is set to 1 to 4 mm and the interval between the continuous sheet joined portions is set to 4 to 8 mm, a sufficient feeling of warmth is obtained. The wrinkles are not easily crushed by the compression.

In addition, when the continuous sheet joint is formed by welding in the longitudinal direction continuous joint form, hard streaks are formed and a reduction in flexibility cannot be avoided, but in the present invention, the continuous sheet joint is formed by an adhesive. The flexibility is not lowered by the material welding, and the flexibility is further improved.

In the present invention, the adhesive for forming the continuous sheet bonding portion is continuous. In the portion where the continuous sheet bonding portion and the elastic elastic member intersect, the first sheet material side and the second sheet material of the elastic elastic member are used. In addition to the form in which the adhesive is continuous in the direction intersecting with the expansion / contraction direction on both sides, the adhesive is continuous on either side because the elastic expansion / contraction member is interposed, but the other side is bonded in the direction intersecting with the expansion / contraction direction The form in which the agent is discontinuous is also included.

Further, as being secured by adhesive to the sheet material at a position where the resilient and elastic members intersect the continuous sheet joint is a resilient and elastic member and the continuous sheet joints at positions intersecting to form a continuous sheet joint In addition to the form in which the elastic elastic member and the sheet material are bonded by an adhesive for the purpose, a form in which an adhesive for fixing the elastic elastic member is separately applied is also included.

  In the case of the present invention, when the interval between the elastic elastic members adjacent to each other (not the central interval) exceeds 10 mm, the thickness of the heel changes in a direction intersecting with the expansion / contraction direction, although it is not as long as the intermittent intermittent joining form. It becomes a cloud shape or waveform. Therefore, in this invention, it is preferable that the space | interval of adjacent elastic elastic members shall be 10 mm or less.

In addition, the first sheet material and the second sheet material are preferably non-woven fabrics. In this case, if the bending resistance in the expansion / contraction direction is low, the wrinkles are thin and sharp and easy to fall down, and the thickness direction The compressibility of the compression becomes poor. In order to improve this, it is conceivable to increase the basis weight of the nonwoven fabric, but there is a possibility that the softness when touched will be poor even if it looks stiff (because the rigidity is improved too much). On the other hand, when a nonwoven fabric having a higher bending resistance in the stretching direction than the bending resistance in the direction orthogonal to the stretching direction is used for the first sheet material and the second sheet material, the wrinkles become round and easy to swell, and the compression recovery property in the thickness direction. As well as becoming richer, the heels are less likely to fall down, and become softer when touched.

  Further, by adopting the elongation rate as described above, the above-described operational effects of the present invention become more remarkable. The elongation rate means a value when the natural length is 100%.

<Invention of Claim 2>
The absorbent article includes an exterior body constituting a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior body, in both sides of the exterior body in the front body and in the back body A pants-type disposable in which both sides of the exterior body are joined to each other to form a side seal portion, so that the waistline portion is formed in an annular shape, and a waist opening and a pair of left and right leg openings are formed. A diaper,
The stretchable structure is provided in a region including at least both sides in the width direction of the interior body in the exterior body so that the elastic stretchable member is in the width direction.
The elastic structure of the absorbent article according to claim 1.

(Function and effect)
The stretchable structure of the present invention is thus suitable for the region located at least on both sides in the width direction of the interior body in the exterior body of the pants-type disposable diaper.

<Invention of Claim 3>
When the region on both sides in the width direction of the interior body in the exterior body is divided into an end region on the interior body side, an end region on the side seal portion side, and an intermediate region located therebetween, the interior body side The absorbent article according to claim 2, wherein an interval between continuous sheet joint portions in at least one of an end region and an end region on the side seal portion side is narrower than an interval between continuous sheet joint portions in the intermediate region. Telescopic structure.

(Function and effect)
Since the continuous sheet joining portion is intermittent in the expansion / contraction direction, a decrease in the fixing force of the elastic expansion / contraction member is unavoidable, and the elastic expansion / contraction member may come off. In particular, it is desirable that the width of each continuous sheet joint portion in the expansion / contraction direction is narrow, but in that case, the position where the elastic expansion / contraction member and the continuous sheet bonding portion intersect becomes small, and the elastic expansion / contraction member is fixed at this small position. It is necessary to secure the fixing force of the elastic elastic member. Therefore, as described above, it is desirable that the interval between the continuous sheet joint portions in the end region is narrower than the interval between the continuous sheet joint portions in the intermediate region, thereby strengthening the fixation.

<Invention of Claim 4>
The stretchable structure of an absorbent article according to any one of claims 1 to 3, wherein an interval between the adjacent elastic stretchable members is 3 to 7 mm.

<Invention of Claim 5>
The adhesive is a hot-melt adhesive having a melt viscosity at a temperature of 140 ° C of 10,000 mPa · s or less, a melt viscosity at a temperature of 160 ° C of 5000 mPa · s or less, and a loop tack adhesive strength of 2000 g / 25 mm or more. The elastic structure of the absorbent article of any one of -4.

(Function and effect)
A hot melt adhesive is preferably used as the adhesive for forming the continuous sheet joint , but when the width of the continuous sheet joint in the expansion and contraction direction is narrow, for example, 1 mm or less, the application width of the hot melt adhesive In addition to being extremely difficult to apply with a coating method that sprays from a nozzle, hot melt bonding is possible even with a pattern coat (transfer of hot melt adhesive with a relief printing method) suitable for narrow width coating Depending on the type of the agent, the hot melt adhesive may be stringed, and there is a risk that the accuracy of the coating width (that is, the width of the continuous sheet joint portion ) will be lowered and the operational stability will be lowered. On the other hand, when a hot melt adhesive having a melt viscosity and a loop tack adhesive force as described above is used, the risk of stringing is reduced, and the coating width accuracy and operational stability can be improved.

  As described above, according to the present invention, there are advantages such as that the wrinkles extend straight, look good, and have excellent breathability, but also have an excellent feeling of fun.

It is a top view in the state where the diaper was developed showing the inside of a pants type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a pants type disposable diaper. FIG. 3 is a 3-3 cross-sectional view of FIG. 1. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. (A) a plan view in an unfolded state, and (b) a 6-6 cross-sectional view in a natural length state, (c) a 6-6 cross-sectional view in an extended state, and (d) a 7-7 cross-sectional view showing a stretchable structure. It is. It is sectional drawing which shows only the principal part of a pants type disposable diaper. It is a perspective view of a pants type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a pants type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a pants type disposable diaper. (A) a plan view in an unfolded state, and (b) a 6-6 cross-sectional view in a natural length state, (c) a 6-6 cross-sectional view in an extended state, and (d) a 7-7 cross-sectional view showing a stretchable structure. It is. (A) a plan view in an unfolded state, (b) a 6-6 cross-sectional view in a natural length state, (c) an 8-8 cross-sectional view in a natural length state, and (d) a 7-7 cross section, showing a conventional stretchable structure FIG. It is a schematic diagram of adhesion equipment. It is a micrograph.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 8 show an example 100 of a pants-type disposable diaper. The pants-type disposable diaper 100 includes an exterior body 12 that forms the outer surface (back surface) of the product, and an interior body 200 that is attached to the inner surface of the exterior body 12. Symbol Y indicates the total length of the diaper, and symbol X indicates the total width of the diaper.

  The interior body 200 is a part that absorbs and holds excrement such as urine, and the exterior body 12 is a part that is worn by the wearer. In addition, the dot pattern part in sectional drawing has shown the junction part which joins each structural member, and is formed by solid, beads, curtains, summits, spiral application, etc., such as a hot-melt-adhesive. The “front-rear direction” means the direction connecting the ventral side (front side) and the back side (rear side), “width direction” means the direction (left-right direction) orthogonal to the front-rear direction, and “up-down direction "In the state of wearing the diaper 100, that is, the direction perpendicular to the waistline direction when the diaper 100 is folded in two at the crotch so that both sides of the front body and the back body of the diaper 100 overlap each other, in other words, For example, it means a direction connecting the waist opening WO side and the crotch side.

(Interior body)
The interior body 200 can take any shape, but is rectangular in the illustrated form. As shown in FIGS. 3 to 5, the interior body 200 includes a surface sheet 30 on the body side, a liquid-impermeable sheet 11, and an absorption element 50 interposed therebetween. Yes, it is the main body that takes up the absorption function. Reference numeral 40 denotes an intermediate sheet (second sheet) provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent element 50. Shows a three-dimensional gather 60 that stands on the body side and is provided on both sides of the interior body 200 in order to prevent excrement from leaking to both sides of the interior body 200.

(Surface sheet)
The top sheet 30 has a property of transmitting liquid, and examples thereof include a porous or non-porous nonwoven fabric, a porous plastic sheet, and the like. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, if flexibility and drapeability are required, the spunbond method and spunlace method are preferable. If bulkiness and softness are required, the air-through method, point bond method, and thermal bond method are preferable processing methods. .

  Further, the top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

  When the three-dimensional gather 60 is provided, both sides of the top sheet 30 pass between the liquid-impermeable sheet 11 and the three-dimensional gather 60 to the back side of the absorbent element 50 to prevent the liquid from penetrating. It is preferable to adhere to the impermeable sheet 11 and the three-dimensional gather 60 with a hot melt adhesive or the like.

(Intermediate sheet)
An intermediate sheet (also referred to as “second sheet”) 40 having a higher liquid permeation rate than the top sheet 30 can be provided to quickly transfer the liquid that has passed through the top sheet 30 to the absorber. This intermediate sheet 40 not only improves the absorption performance of the absorbent by quickly transferring the liquid to the absorbent body, but also prevents the “reversed” phenomenon of the absorbed liquid from the absorbent body, so that the top sheet 30 is always dried. It can be in a state of being. The intermediate sheet 40 can be omitted.

Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace, spunbond, SMS, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric is preferable because it is bulky. It is preferable to use a core-sheath composite fiber for the air-through nonwoven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. Basis weight is preferably ^{20~80g / m 2, 25~60g / m} 2 is more preferable. The thickness of the raw fiber of the nonwoven fabric is preferably 2.2 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use an eccentric fiber, a hollow fiber, or an eccentric and hollow fiber that does not have a core at the center as the mixed fiber of all or part of the raw fiber.

  The intermediate sheet 40 in the illustrated form is disposed in the center shorter than the width of the absorber 56, but may be provided over the entire width. The length of the intermediate sheet 40 in the longitudinal direction may be the same as the length of the absorbent body 56 or may be within a short length range centered on the region that receives the liquid.

(Liquid impervious sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited. For example, a plastic film made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric provided with a plastic film on the surface of the nonwoven fabric, or a plastic film For example, a laminated sheet in which a nonwoven fabric or the like is laminated and bonded to each other can be exemplified. For the liquid-impermeable sheet 11, it is preferable to use a liquid-impervious and moisture-permeable material that has been preferred in recent years from the viewpoint of preventing stuffiness. As a plastic film having moisture permeability, a microporous plastic film obtained by kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching in a uniaxial or biaxial direction. Is widely used. In addition, non-woven fabric using microdenier fiber, enhancement of leakproofness by reducing the voids of the fiber by applying heat or pressure, application of superabsorbent resin or hydrophobic resin or water repellent Thus, a sheet that is liquid-impermeable without using a plastic film can also be used as the liquid-impermeable sheet 11.

  The liquid-impermeable sheet 11 is preferably extended around both sides of the absorbent element 50 to both sides of the side surface 30 of the absorbent element 50 in order to improve leakage prevention. The width of this extended portion is suitably about 5 to 20 mm on each of the left and right sides.

  Moreover, the excretion indicator from which a color changes by absorption of a liquid part can be provided in the inner side of the liquid-impermeable sheet 11, especially the absorber 56 side surface.

(Three-dimensional gather)
The three-dimensional gather 60 is a belt-like member that extends over the entire front-rear direction along both side portions of the interior body 200, blocks urine and soft stool that move in the lateral direction along the top sheet 30, and prevents side leakage. It is provided for this purpose. The three-dimensional gather 60 of the present embodiment is provided so as to stand up from the side portion of the interior body 200, the base side portion rises obliquely toward the center in the width direction, and the tip side portion from the intermediate portion has a width. It stands up diagonally outward in the direction.

  More specifically, the three-dimensional gather 60 folds the belt-shaped gather sheet 62 having a length equal to the length in the front-rear direction of the interior body 200 in the width direction and folds it into two. In addition, a plurality of elongated elastic elastic members 63 are fixed along the longitudinal direction at intervals in the width direction. An end portion of the three-dimensional gather 60 opposite to the folded portion in the width direction is an attachment portion 65 fixed to the back surface of the side edge portion of the interior body 200, and portions other than the attachment portion 65 protrude from the attachment portion 65. It is set as the protrusion part 66 (part by the side of a folding | turning part). Further, both end portions in the front-rear direction of the protruding portion 66 extend from the mounting portion 65 to the side surface of the topsheet 30 through the side portion of the interior body 200 and are hot-melted to the side surface of the topsheet 30. The base side portion is fixed to the front and rear fixing portion 67 by an adhesive or heat seal, and the tip side portion is folded back outward in the width direction from the tip of the base side portion and fixed to the base side portion. An intermediate part in the front-rear direction of the protruding part is an unfixed free part (inner free part), and an elongated elastic member 63 extending in the front-rear direction is fixed to the free part in an extended state.

The gather sheet 62 is made of a spunbond nonwoven fabric (SS, SSS, etc.), an SMS nonwoven fabric (SMS, SSMMS, etc.), a melt-blown nonwoven fabric with excellent uniformity and concealment, and water repellent with silicone if necessary. A treated product can be suitably used, and the fiber basis weight is preferably about 10 to 30 g / m ² . As the elongated elastic elastic member 63, rubber thread or the like can be used. When spandex thread rubber is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation rate at the time of fixation is preferably 150 to 350%, more preferably 200 to 300%. The term “elongation rate” means a value when the natural length is 100%. Further, as shown in the drawing, a waterproof film 64 can be interposed between the gather sheets folded in two.

  2-6 are preferable and, as for the number of the elongate elastic expansion-contraction members 63 provided in the free part of the three-dimensional gather 60, 3-5 are more preferable. The arrangement interval 60d is suitably 3 to 10 mm. If comprised in this way, in the range which has arrange | positioned the elongate elastic expansion-contraction member 63, it will become easy to contact | abut with respect to skin. The elongated elastic elastic member 63 may be disposed not only at the distal end side but also at the base side.

  The fixing target of the attachment portion 65 of the three-dimensional gather 60 can be an appropriate member such as the top sheet 30, the liquid-impermeable sheet 11, and the absorbent element 50 in the interior body 200.

  In the three-dimensional gather 60 thus configured, the contraction force of the elongated elastic elastic member 63 acts so that both ends in the front-rear direction are brought close to each other, but the both ends in the front-rear direction of the protruding portion 66 are fixed so as not to stand up. On the other hand, since they are non-fixed free portions, only the free portions stand up against the body side as shown in FIG. In particular, when the attachment portion 65 is positioned on the back surface side of the interior body 200, the three-dimensional gather 60 stands up so as to open outward in the width direction at the crotch portion and in the vicinity thereof. It comes in contact, and the fit is improved.

  The dimensions of the three-dimensional gather 60 can be determined as appropriate. In the case of an infant paper diaper, for example, as shown in FIG. 7, the standing height of the three-dimensional gather 60 (the length in the width direction of the protruding portion 66 in the unfolded state) 66w is It is preferably 15 to 60 mm, particularly 20 to 40 mm. In addition, the distance 60d between the folds located on the innermost side in a state where the three-dimensional gather 60 is flatly folded so as to be parallel to the surface of the topsheet 30, is preferably 60 to 190 mm, particularly preferably 70 to 140 mm.

  Note that, unlike the illustrated embodiment, the three-dimensional gathers can be provided in double (two rows) on the left and right sides of the interior body 200.

(Absorption element)
The absorbent element 50 includes an absorbent body 56 and a packaging sheet 58 that wraps the entire absorbent body 56. The packaging sheet 58 can be omitted.

(Absorber)
The absorber 56 can be formed of an aggregate of fibers. As this fiber assembly, a filament assembly obtained by opening, as necessary, synthetic fiber tows (fiber bundles) such as cellulose acetate as well as short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber basis weight can be set to, for example, about 100 to 300 g / m ² when cotton-like pulp or short fibers are stacked, and in the case of a filament aggregate, for example, about 30 to 120 g / m ^2. Can do. The fineness in the case of a synthetic fiber is 1-16 dtex, for example, Preferably it is 1-10 dtex, More preferably, it is 1-5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The degree of crimp of the crimped fibers can be, for example, about 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per 2.54 cm. Further, a crimped fiber that is uniformly crimped is often used. It is preferable to disperse and hold superabsorbent polymer particles in the absorber 56.

  Although the absorbent body 56 may be rectangular, as shown in FIG. 6, as shown in FIG. 6, the hourglass has a front end portion, a rear end portion, and a narrow portion narrower than the front end portion and the rear end portion. The shape is preferable because the fit of the absorber 56 itself and the three-dimensional gather 60 around the legs is improved.

  Moreover, although the dimension of an absorber can be determined suitably, it is preferable to extend to the peripheral part of the interior body, or its vicinity in the front-back direction and the width direction. Reference numeral 56X indicates the width of the absorber 56.

(Superabsorbent polymer particles)
The absorber 56 can contain superabsorbent polymer particles in a part or all thereof. Superabsorbent polymer particles include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used in this type of absorbent article can be used as they are, and those having a particle size of 1000 μm or less, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the liquid supplied into the absorber 56 returns to the outside of the absorber 56 is likely to occur.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is difficult to secure the absorption amount. When it exceeds 350 g / m ² , the effect is saturated.

  If necessary, the superabsorbent polymer particles can adjust the spraying density or spraying amount in the plane direction of the absorber 56. For example, it is possible to increase the application amount of the liquid excretion site as compared to other sites. When gender differences are taken into account, men can increase the front spray density (amount), while women can increase the center spray density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorber 56 can also be provided.

(Packaging sheet)
When the packaging sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and the material can be polypropylene, polyethylene / polypropylene composite material, or the like. The basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

  The packaging form of the packaging sheet 58 can be determined as appropriate, but from the viewpoint of ease of manufacture and prevention of leakage of the superabsorbent polymer particles from the front and rear end edges, the cylinder is formed so as to surround the front and back surfaces and both side surfaces of the absorbent body 56. It is preferable that the front and rear edges of the absorbent body 56 are protruded from the front and back of the absorbent body 56, and the protruding portions are crushed in the front and back directions and joined by a joining means such as a hot melt adhesive.

(Exterior body)
The exterior body 12 has a part constituting a front body F extending from the crotch part to the abdomen and a part constituting a rear body B extending from the crotch part to the back side, and both sides of the front body F As shown in FIG. 8, a waist opening WO for passing the wearer's torso and a pair of left and right leg openings LO for passing the legs are formed. It is what. Reference numeral 12A denotes a joining portion (hereinafter, this portion is also referred to as a side seal portion). The crotch portion means the center in the front-rear direction from the waist edge of the front body F to the waist edge of the back body B in the unfolded state, and the front side part and the back side part thereof are the front body F and the back body part. B means each.

  The exterior body 12 includes a waist portion T defined as a front-rear direction range extending from the waist opening WO to the upper end of the leg opening LO, and a front-rear direction range of a portion forming the leg opening LO (a side seal portion 12A of the front body F). And an intermediate portion L defined as a front / rear direction region having the side seal portion 12A of the back body B. The waistline T can be divided into a “waist edge” W that conceptually forms the edge of the waist opening, and a “waist lower part” U that is a lower part than this. These lengths in the vertical direction vary depending on the size of the product and can be determined as appropriate. For example, the waist edge W may be 15 to 40 mm, and the waist lower portion U may be 65 to 120 mm. On the other hand, both side edges of the intermediate portion L are bundled along the circumference of the wearer's leg, and this is a portion into which the wearer's leg is put. As a result, the exterior body 12 has a substantially hourglass shape as a whole. The degree of tightness of the exterior body 12 can be determined as appropriate. In order to obtain a clean appearance as shown in FIGS. Although it is preferable, the narrowest part may be determined so as to be equal to or larger than the width of the interior body 200.

  As shown in FIGS. 3 to 6, the exterior body 12 is formed by joining two sheet materials 12 </ b> S and 12 </ b> H, and the second sheet material 12 </ b> H located on the inner side is formed of the waist opening WO. Although extending only to the edge, the first sheet material 12S located on the outer side wraps around the edge on the waist side of the second sheet material 12H and is folded back to the inner side. It extends so that it may cover even to the waist side edge part.

  The sheet materials 12S and 12H can be used without particular limitation as long as they are in sheet form, but are preferably non-woven fabrics. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method.

  And in the exterior body 12, in order to improve the fitting property with respect to the trunk periphery, elongated elastic elastic members 15 to 17 such as thread rubber are provided between the sheet materials 12S and 12H at a predetermined elongation rate. As the elongated elastic elastic members 15 to 17, synthetic rubber or natural rubber may be used.

More specifically, the entire width direction is continuous between the inner surface of the second sheet material 12H and the outer surface of the folded portion 12r of the first sheet material 12S at the waist edge W of the back body B and the front body F. As described above, the plurality of waist edge elastic elastic members 17 are fixed in a state of being spaced apart in the vertical direction and extended along the width direction at a predetermined extension rate. In addition, one or more of the waist edge elastic elastic members 17 disposed in a region adjacent to the waist lower portion U may overlap with the interior body 200 or may be overlapped with the interior body 200 in the width direction. You may each provide in the width direction both sides except a center part. The waist edge elastic elastic member 17 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to the rubber thread of 1.0mm about ^2), 3 to 22 present approximately at intervals of 4 to 12 mm, respectively elongation from 150% to 400%, preferably fixed in particular about 220-320%. Further, the waist edge elastic elastic members 17 need not all have the same thickness and elongation rate. For example, the elastic elastic members may have different thicknesses and elongation rates at the upper and lower portions of the waist edge W. .

  Further, between the outer side surface of the second sheet material 12H and the inner side surface of the first sheet material 12S in the lower waist portion U of the front body F and the back body B, except for the central portion in the width direction overlapping the interior body 200, A plurality of lower waist elastic elastic members 15 made of an elongated elastic elastic member are continuously provided over the entire width direction on each of the upper side and both sides in the width direction, with a predetermined elongation rate at intervals in the vertical direction. It is fixed in the state extended | stretched along the width direction.

The waist lower elastic elastic member 15 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to 1. It is preferable to fix the thread rubber of about 0 mm ^{2 at} a spacing of 1 to 15 mm, particularly 3 to 8 mm, and an elongation rate of 200 to 350%, particularly about 240 to 300%.

  In addition, between the outer side surface of the second sheet material 12H and the inner side surface of the first sheet material 12S in the intermediate portion L of the front body F and the back body B, except for the center portion in the width direction overlapping the interior body 200, A plurality of intermediate elastic expansion / contraction members 16 made of an elongated elastic expansion / contraction member are provided in each part on both sides in the width direction so as to be continuous over the entire width direction. It is fixed in a stretched state along the direction.

The intermediate elastic elastic member 16 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to 1. It is preferable to fix the thread rubber of about 0 mm ² ) at intervals of 5 to 40 mm, particularly 5 to 20 mm, and stretch ratios of 150 to 300%, particularly 180 to 260%, respectively.

  As shown in the figure, when the waist lower elastic elastic members and the intermediate elastic elastic members 15 and 16 are provided on both sides in the width direction except for the central portion in the width direction overlapping the inner body 200, the inner body 200 is provided. Will not shrink more than necessary in the width direction, and it will not look bad or absorb. In this form, in addition to the form in which the elastic stretchable member exists only on both sides in the width direction, the elastic stretchable member exists from one side of the width direction to the other side across the interior body 200, but overlaps the interior body 200. At the center in the width direction, the elastic expansion / contraction member is finely cut, and the contraction force does not act (substantially equivalent to not providing the elastic expansion / contraction member), and only the both sides in the width direction are configured as the contraction force acting portions. Are also included. Of course, the arrangement of the waist lower elastic members 15 and 16 is not limited to the above example, and the waist lower elastic members and the waist lower elastic members so that the elastic force acts over the entire width of the waist lower U. Part or all of the intermediate elastic elastic members 15 and 16 can be provided from one side in the width direction to the other side across the interior body 200.

(External body split structure)
In the above-described example, the front body F to the back body B are continuously covered by the integrated exterior body 12, but the abdominal part exterior body and the back part exterior body are continuously located on the crotch side. In this case, the outer surface of the interior body covers a portion exposed between the exterior body of the abdominal side portion and the exterior body of the back side portion. A crotch outer body can also be attached. As the crotch outer casing, the same materials as those used for the outer casing described above can be used.

(About stretchable structure)
In the present pants-type disposable diaper, the stretchable structure of the present invention is adopted in the region from the lower waist portion U to the middle portion L. That is, as shown in FIG. 6, the portion is predetermined in a direction intersecting with the expansion / contraction direction (orthogonal in the illustrated embodiment) in which the first sheet material 12 </ b> S and the second sheet material 12 </ b> H are intermittently arranged in the expansion / contraction direction. The continuous sheet joining portion 70 is formed by joining with an adhesive 71 (hot melt adhesive 71 or the like) that is continuous with a width of 1 mm. Width 70w of expansion and contraction direction of the continuous sheet junction 70 is a 1 to 4 mm, interval 70d successive adjacent sheet joined portion 70 is set to 4 to 8 mm (preferably 5 to 7 mm). The lower limit of the width 70w in the expansion / contraction direction of the continuous sheet joining portion 70 is preferably 1 mm from the viewpoint of ease of manufacture. On the other hand, the upper limit of the width 70w in the expansion / contraction direction of the continuous sheet joining portion 70 is preferably 2 mm, and more preferably 1.5 mm.

Although the raw material of the 1st sheet material 12S and the 2nd sheet material 12H is not specifically limited, It is desirable that it is especially a nonwoven fabric with a thickness of 0.1-1 mm and a fabric weight of 10-20 g / m < ² >, respectively. In addition, the 1st sheet material 12S and the 2nd sheet material 12H are each comprised from the nonwoven fabric of one sheet, and either or both may be a laminated body of the nonwoven fabric of several sheets.

  In particular, the air permeability, appearance, and feeling of warmth of the heel 80, which are problems of the present invention, are more difficult to ensure as the nonwoven fabric is more flexible. That is, the ridge 80 is thin and easily falls down, and the compression / restoration property tends to be poor. Therefore, the structure of the present invention is suitable for such a case. That is, at least one of the first sheet material 12S and the second sheet material 12H is a non-woven fabric of polypropylene (PP) or a copolymer thereof (for example, a copolymer in which polyethylene or ethylene is blended as a copolymerization component) (hereinafter also referred to as a PP-based non-woven fabric). ) And a non-woven fabric of core-sheath fiber (PE / PP) using polyethylene (PE) as a sheath and polypropylene (PP) as a core component. In addition, the type of the nonwoven fabric is not particularly limited, but a spunbond nonwoven fabric is preferable from the point of excellent strength and flexibility, and in particular, a spunbond nonwoven fabric formed by laminating a plurality of spunbond layers, for example, SS nonwoven fabric (two layers), An SSS nonwoven fabric (three layers) can be suitably used, and four or more layers can also be used.

The elastic elastic members 15 and 16 are fixed to at least one of the first sheet material 12 </ b> S and the second sheet material 12 </ b> H by an adhesive 71 at a position intersecting with the continuous sheet bonding portion 70. It can also be applied a different adhesive from the continuous sheet junction for forming for fixing the resilient and elastic members 15 and 16 elastically stretchable member or sheet member 12S, the 12H, in the illustrated embodiment, a continuous sheet junction 70 Since the adhesive 71 for forming the belt is continuous in the direction intersecting the expansion / contraction direction, the elastic expansion / contraction members 15 and 16 are made to be at least one of the first sheet material 12S and the second sheet material 12H using the adhesive 71. It is fixed on one side. At the time of manufacture, the adhesive 71 is applied to one or both of the first sheet material 12S and the second sheet material 12H, and when the both sheet materials 12S and 12H are joined, the elastic elastic members 15 and 16 are attached to the both sheet materials 12S. , 12H.

In the form shown in FIG. 6, the adhesive 71 is continuously applied to the surface of the first sheet material 12S on the second sheet material 12H side intermittently in the expansion / contraction direction and with a predetermined width in the direction intersecting the expansion / contraction direction. The elastic elastic members 15 and 16 are extended between the first sheet material 12S and the second sheet material 12H without applying the adhesive 71 on the surface of the second sheet material 12H on the first sheet material 12S side. The first sheet material 12S and the second sheet material 12H, and the first sheet material 12S and the elastic elastic members 15 and 16 are joined by an adhesive 71, respectively. In this case, the adhesive 71 continues in the direction intersecting the expansion and contraction direction on the first sheet material 12S side of the elastic expansion and contraction members 15 and 16 among the portions where the continuous sheet joining portion 70 and the elastic expansion and contraction members 15 and 16 intersect. Accordingly, the elastic stretch members 15 and 16 are fixed to the first sheet material 12S, and the adhesive 71 is discontinuous in the direction intersecting the stretch direction on the second sheet material 12H side of the elastic stretch members 15 and 16. In the figure, this discontinuous portion is indicated by reference numeral 72. Since the adhesive 71 is intermittently present in the second sheet material 12H, the decrease in flexibility of the second sheet material 12H, and thus the decrease in flexibility of the first sheet material 12S and the second sheet material 12H as a whole is suppressed. it can. In addition, the elastic elastic members 15 and 16 are continuous with the first sheet material 12S only at the portion intersecting with the continuous sheet bonding portion 70, but the elastic elastic members 15 and 16 are provided on both sides of the continuous sheet bonding portion 70 with the continuous sheet bonding portion 70. Since the first sheet material 12S and the second sheet material 12H are integrated, the contraction force of the elastic elastic members 15 and 16 acts substantially the same as the first sheet material 12S and the second sheet material 12H, and the first Equal wrinkles can be formed on both the sheet material 12S and the second sheet material 12H.

In addition, it is also possible to apply the adhesive 71 in the same pattern to the first sheet material 12S and the second sheet material 12H. In this case, as shown in FIG. 11, the first sheet material 12S side and the second sheet material 12H side of the elastic stretch members 15 and 16 among the portions where the continuous sheet joining portion 70 and the elastic stretch members 15 and 16 intersect. In both cases, since the adhesive 71 is continuous with a predetermined width in a direction crossing the expansion / contraction direction, there is an advantage that the elastic expansion / contraction members 15 and 16 can be more firmly fixed. Although not shown, it is also possible to apply an adhesive to the second sheet material, and to fix the first sheet material by inserting an elastic elastic member without applying the adhesive. However, in these forms, since the adhesive 71 is continuous in the second sheet material 12H, not only the flexibility of the second sheet material 12H itself to be brought into contact with the skin is lowered, but also the reduced portion of the flexibility is an elastic elastic member. Since it presses against skin by 15 and 16, it is not so preferable. Therefore, it is desirable that the adhesive 71 is not continuous on the side having a surface that comes into contact with the wearer's skin like the second sheet material 12H as shown in FIG.

A hot melt adhesive 71 is preferably used as the adhesive 71 for forming the continuous sheet bonding portion 70. Examples of the hot melt adhesive 71 include EVA, adhesive rubber (elastomer), olefin, polyester / polyamide, and the like. It is desirable to use

The application method of the hot melt adhesive 71 is not particularly limited, but when the width 70w in the expansion / contraction direction of the continuous sheet joining portion 70 is narrow, for example, 1 mm or less, the application width of the hot melt adhesive becomes narrow, Since it is difficult to apply by intermittent application by an application method such as a curtain or a solid sprayed from a nozzle, it is desirable to adopt a pattern coat suitable for narrow width application (transfer of the hot melt adhesive 71 by a relief printing method). . FIG. 13 shows an example of a production facility for a stretchable structure when a pattern coat of a hot melt adhesive is used. That is, this example of the pattern coat type equipment includes elastic elastic members 15, 16 between the second sheet material 12H and the first sheet material 12S in which the hot melt adhesive 71 is applied to the surface on the second sheet material 12H side. 6 is fed between a pair of nip rolls 101 and pressed to form the stretchable structure shown in FIG. Before the first sheet material 12S is fed into the nip roll 101, the first sheet material 12S is brought into contact with the plate roll 102 having an intermittent convex pattern in the circumferential direction, and intermittently in the transport direction (MD direction, which is the direction of expansion and contraction). In addition, the hot melt adhesive 71 is transferred and applied continuously in a direction (CD direction) intersecting the transport direction. Reference numeral 103 denotes a hot melt adhesive supply roll (anilox roll in letterpress printing) for transferring and applying the hot melt adhesive 71 to the convex pattern of the plate roll 102 at a predetermined thickness, and reference numeral 104 denotes hot melt adhesion. The supply nozzle which supplies the hot-melt-adhesive 71 to the agent supply roll 103 is shown.

However, even when such a coating method using a pattern coat is adopted, depending on the type of the hot melt adhesive 71, the hot melt adhesive 71 may be stringed, and the coating width (that is, the continuous sheet joining portion 70) Width)) and the operational stability may be reduced. Therefore, as the hot melt adhesive 71, one having a melt viscosity at a temperature of 140 ° C. of 10,000 mPa · s or less, a melt viscosity at a temperature of 160 ° C. of 5000 mPa · s or less, and a loop tack adhesion of 2000 g / 25 mm or more is used. desirable. Thereby, the possibility of stringing is reduced, and the application width accuracy and operational stability can be improved.

The loop tack adhesive strength of the hot melt adhesive 71 means a value measured as follows. That is, the hot melt adhesive is applied to a thickness of 50 μm on a PET plate having a thickness of 50 μm. This is cut into a size of 25 mm in width and 125 mm in length to form a tape, and then the two ends of the tape are overlapped to form a loop. This loop is fixed to an LT-100 type loop tack tester (manufactured by Chem Instrument Co., Ltd.), and then bonded to a PE (polyethylene) plate with a bonding area of 25 mm × 25 mm and a bonding time of 2 seconds. Next, the loop-shaped tape is peeled off at 20 ° C. at a peeling speed of 300 mm / min, and the maximum force is measured to obtain the loop tack adhesive force.
The melt viscosity of the hot melt adhesive 71 is measured at a specified temperature using a Brookfield B-type viscometer (spindle No. 027) in accordance with JIS Z 8803.

  The distances 15d and 16d between the adjacent elastic elastic members 15 and 16 can be determined as appropriate. However, if the distance exceeds 10 mm, the thickness of the flange 80 changes in a direction crossing the expansion / contraction direction, although not as long as the longitudinal intermittent joining form. In the present invention, the distances 15d and 16d between the adjacent elastic elastic members 15 and 16 are preferably 10 mm or less, particularly 3 to 7 mm.

  The thickness and elongation rate of the elastic elastic members 15 and 16 (elongation rate when the elastic structure is fully deployed) may be appropriately selected according to the mounting position of the elastic elastic members 15 and 16, and the preferred range is as follows. As described above. In general, it is desirable that the elastic elastic members 15 and 16 have a thickness of about 300 to 1,000 dtex and an elongation rate of about 200 to 350%.

In the expansion / contraction structure described above, as the elastic expansion / contraction members 15 and 16 contract, as shown in FIG. 6B, the expansion / contraction members 15 and 16 are positioned between the continuous sheet joining portions 70 in the first sheet material 12 </ b> S and the second sheet material 12 </ b> H. Each part contracts and swells in opposite directions to form a ridge 80. FIG. 6 (b) shows a natural length state, but the elastic elastic members 15 and 16 are stretched to some extent from this state when worn, and as shown in FIG. The height 80h of the ridge 80 is lowered. Moreover, since this expansion-contraction structure is a longitudinal direction continuous joining form, the collar 80 extended straight along the continuous sheet joining part 70 is formed, and it is excellent in air permeability and appearance.

The width 70w in the expansion / contraction direction of each continuous sheet joining portion 70 affects the interval between adjacent ridges 80, and this width is 4 mm when the formed ridge 80 is thin as in the case of the longitudinal continuous joining form. If it exceeds, the space between the adjacent ridges 80 becomes too wide, and not only the individual ridges 80 look independent, but also when the ridges 80 are crushed by the compressive force in the thickness direction or deformed such as falling down, they are adjacent. As a result of weakening the function of supporting the heel 80, the resistance to deformation or the restoration after the change becomes weak, and as a result, the feeling of fun is insufficient.

In addition, when the width 70w in the expansion / contraction direction of the continuous sheet joining part 70 is simply set to 1 to 4 mm, and the interval 70d between the adjacent continuous sheet joining parts 70 is less than 4 mm or more than 8 mm, the following occurs. That is, the interval 70d between the adjacent continuous sheet joint portions 70 affects the height 80h and the width of the flange 80, and when the interval between the adjacent continuous sheet joint portions is about 2 mm, The ridge 80 is poor in continuity in the same vertical direction (there is no need to intermittently provide the continuous sheet joining portion 70 in the expansion / contraction direction), but at 3 mm, the ridge 80 extends straight in a direction perpendicular to the expansion / contraction direction. The effect that the adjacent ridges 80 support each other cannot be expected, and the sense of funiness is insufficient. Moreover, if the space | interval 70d of the continuous sheet junction part 70 exceeds 8 mm, the wrinkle 80 will be crushed irregularly by compression at the time of packaging, and the appearance of a product will worsen. On the other hand, when the width 70w of the continuous sheet joining portion 70 in the expansion / contraction direction is set to 1 to 4 mm and the interval 70d between the continuous sheet joining portions 70 is set to 4 to 8 mm, a sufficient feeling of warmth is obtained. The bag 80 is not easily crushed irregularly due to compression during packaging. Moreover, if the continuous sheet joining portion 70 is formed by welding in the longitudinal continuous joining form, a hard streak is formed and a reduction in flexibility is inevitable, but in the present invention, the continuous sheet joining portion 70 is formed by the adhesive 71. Therefore, a decrease in flexibility due to material welding does not occur, and the flexibility is further improved.

  As the first sheet material 12S and the second sheet material 12H, a non-woven fabric is suitable. In this case, if the bending resistance in the expansion / contraction direction is low, the wrinkle 80 becomes thin and sharp, and easily collapses. The compressibility of the direction is poor. In order to improve this, it is conceivable to increase the basis weight of the nonwoven fabric, but there is a possibility that the softness when touched will be poor even if it looks stiff (because the rigidity is improved too much). Therefore, a nonwoven fabric is used as the first sheet material 12S and the second sheet material 12H, and the bending resistance in the stretching direction is made higher than the bending resistance in the direction orthogonal to the stretching direction. As a result, the heel 80 becomes round and easy to bulge, and the compression recovery property in the thickness direction is enhanced, and the heel 80 is less likely to fall down and soft when touched. The first sheet material 12S and the second sheet material 12H each have a bending resistance of 40 to 55 mm in a stretching direction, and a bending resistance of 25 to 35 mm in a direction perpendicular to the stretching direction.

  Here, the bending resistance of the nonwoven fabric means a value measured according to the bending resistance A method (45-degree cantilever method) of JIS L1096: 2010 “Testing method for fabrics and knitted fabrics”.

  In order to make the bending resistance in the direction orthogonal to the stretching direction of the nonwoven fabric less than the bending resistance in the stretching direction, the fiber orientation of the nonwoven fabric may be configured along the stretching direction. Here, the fiber orientation is the direction along which the fibers of the nonwoven fabric are along, and “the fiber orientation is along the stretch direction” means that 100% of the total fiber weight constituting the nonwoven fabric is fiber oriented in the stretch direction. The thing from 50 to 50% or more is what is made to have fiber orientation in the range of -45 degrees-+45 degrees with respect to the expansion-contraction direction. The measurement method generally used can be used for the measuring method of the fiber orientation of a nonwoven fabric. Examples of measurement methods include a measurement method according to the TAPPI standard method T481 fiber orientation test method based on zero-range tensile strength, and a simple measurement that determines the fiber orientation direction from the stretching direction and the tensile strength ratio in the orthogonal direction. A method can be mentioned. In the latter simple measuring method, a test piece having a length of 200 mm and a width of 50 mm is subjected to a tensile test using a tensile tester under the conditions of a crosshead speed of 500 mm / min and a distance between chucks of 150 mm. If the tensile strength is obtained from the maximum load and the ratio of tensile strength (stretching direction / orthogonal direction) is greater than 1, the fiber orientation is assumed to be along the stretching direction.

In the stretchable structure of the present invention, since the continuous sheet joining portion 70 is intermittent in the stretchable direction, a decrease in the fixing force of the elastic stretchable members 15 and 16 is unavoidable, and the elastic stretchable members 15 and 16 may come off. . In particular, the width 70w of the expansion and contraction direction of the continuous sheet junction 70 is narrow, it is desirable, in which case, the position where the elastic stretchable members 15 and 16 and the continuous sheet junction 70 intersects decreases, the elastic in this small position It is necessary to fix the elastic members 15 and 16, and securing the fixing force of the elastic elastic members 15 and 16 is important.

To solve this, as shown in FIG. 9, regions on both sides in the width direction of the interior body 200 in the exterior body 12 are defined as an end region on the interior body 200 side, an end region on the side seal portion 12A side, when divided into an intermediate region located between the continuous separation Di between continuous sheet joint 70 in the end regions and the end regions of the side seal portion 12A side of the inner body 200, the Ds in the middle region the sheet bonding portion 70 It is desirable to make it smaller than the interval Dm.

Further, instead of the configuration shown in FIG. 9 (which may be combined with the configuration shown in FIG. 9), as shown in FIG. 10, the elasticity in the end region on the inner body 200 side and the end region on the side seal portion 12A side is shown. One preferable mode is to make the fixed widths Wi and Ws of the elastic members 15 and 16 (equal to the width 70w in the expansion and contraction direction of the continuous sheet joint 70 in the illustrated embodiment) wider than the fixed width Wm of the elastic expansion and contraction member in the intermediate region. It is.

  In addition, since the elastic expansion members 15 and 16 of the exterior body 12 of the pants-type disposable diaper are firmly fixed at the side seal portion 12A at the end portions in the width direction, the end regions on the side seal portion 12A side are It is also a preferable form that the fixing strengthening means is omitted.

(Other)
The above example is an example of application to the part from the waist lower part U to the middle part L of the pants-type disposable diaper, but it may be applied including the waist edge W, and the elastic elastic member 16 of the middle part L May be omitted. Moreover, the above-mentioned expansion-contraction structure is applicable also to other expansion-contraction parts, such as the trunk | drum circumference part of the back side part of a tape type disposable diaper described in the term of the prior art, and a three-dimensional gather.

<Experiment 1>
Fineness 1.6 denier, basis weight 17 g / m ² , thickness 0.2 mm (initial thickness T0: thickness under pressure of 0.5 g / cm ² ), MD softness (direction of nonwoven fabric production line) 55 mm, A polypropylene fiber SSS nonwoven fabric having a bending resistance of 28 mm in the CD direction (direction perpendicular to the MD direction) is cut to prepare a first sheet material and a second sheet material having a length of 180 mm in the MD direction and a length of 40 mm in the CD direction. did. Moreover, a 470 dtex rubber thread was prepared as an elastic elastic member.
Then, a hot melt adhesive having a width of 1 mm and continuous in the CD direction is applied to the surface of the first sheet material on the second sheet material side with an interval of 7 mm in the MD direction, and further, continuous in the MD direction. 7 pieces of rubber thread are arranged in the CD direction at intervals of 5 mm, 270% of each stretched state, and the second sheet material is placed over the first sheet material so that the MD direction and the CD direction match the first sheet material. The material, the elastic elastic member and the second sheet material are pressure-bonded, and the elastic sheet sample No. 1 was produced. In addition, this sample No. The natural length of 1 in the MD direction was 67 mm. Further, the application width of the hot melt adhesive was appropriately changed to 2 mm, 4 mm, 6 mm, and 10 mm, and the application interval of the hot melt adhesive was appropriately changed to 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm. 2 to 13 were also produced.
Observe the formation of wrinkles in these samples, ◎: The walls are very clean,
○: Evaluation was made in four stages: 襞 was formed beautifully, △: 襞 was formed but not beautiful, ×: 襞 was insufficiently formed. The evaluation results are as shown in Table 1. In addition, although the wrinkle was formed when the application | coating space | interval of a hot-melt-adhesive was 10 mm, it was too large and it was crushed at the time of compression, and the wrinkle was not formed in 2 mm. Further, when the application width of the hot melt adhesive was 6 mm and 10 mm, the sheet joint portion was also contracted to form wrinkles.

From this result, the application width of the hot melt adhesive (that is, the width in the expansion / contraction direction of the continuous sheet bonding portion ) is 1 to 4 mm, and the application interval of the hot melt adhesive (that is, the interval between adjacent continuous sheet bonding portions ). It can be seen that a desirable result is obtained when the thickness is 4 to 8 mm.

<Experiment 2>
In the same manner as in Experiment 1 (however, the application width of the hot melt adhesive was 2 mm, the application interval was 6 mm), the sample No. of the stretchable sheet was changed. 14 was produced.
Sample No. 1 except that the continuous direction of the hot melt adhesive was the MD direction of the first sheet material and the second sheet material, and the direction of the thread rubber was the CD direction of the first sheet material and the second sheet material. In the same manner as in sample 14, 15 was created.
These sample Nos. 14 and no. 15 is a natural length, and the center of the pressure plate described later is aligned with the top position of the heel for five ridges, and compression characteristics (compression rigidity LC, compression energy WC, compression resilience RC, initial thickness T0, maximum load Thickness TM) was measured and the average value was calculated. The compression stiffness LC is closer to 1, meaning that the compression stiffness is greater. The larger the compression energy WC is, the easier the compression is. The compression resilience RC is closer to 100, and the compression recovery is better. Means. The initial thickness T0, compression stiffness LC, compression energy WC, and compression resilience RC are measured using a KES-FB3-AUTO-A automated compression tester based on KES (Kawabata's Evaluation System for Fabrics). Measurements between steel pressure plate with a circular plane of compression area 2 cm ^2, the sample was compressed from 0N / cm ² to a maximum compressive load 0.49 N / cm ^2, carried out between undo. The initial thickness T0 is the thickness of the sample at a pressure of 0.0049 N / cm ² . The compression stiffness LC represents the linearity of the compression displacement, and the value increases as the load and the displacement (thickness reduction due to compression) are proportional. The compression energy WC represents the work of compression, and the larger the value, the better the feeling of swelling and the feeling of lower back. The compression resilience RC represents compression recovery, and the larger the numerical value, the smaller the hysteresis.

  In addition, these sample Nos. 14 and no. 15 is stretched about 1.65 times in the MD direction (assuming a diaper wearing state), and a microscopic image is taken from the side (magnification 30 times). The width 80X was measured for each ridge 80, and the average value was calculated. The photograph taken is shown in FIG. 14 and the height and width of the ridge are shown in Table 3. A KEYENCE digital microscope VHX-1000 was used for microscopic photography.

  From these results, when the stiffness in the stretch direction of the nonwoven fabric is made higher than the stiffness in the direction perpendicular to the stretch direction, the wrinkles become round and easy to swell, and the compressive recoverability in the thickness direction becomes rich, and the wrinkles collapse. It turns out that it becomes harder and softer when touched.

<Experiment 3>
Prepare the same first sheet material, elastic elastic member and second sheet material as in Experiment 1, and various hot melt adhesives with different melt viscosities and loop tack adhesive forces, and use the same equipment as shown in FIG. Adhesion test is performed at a speed of 187 m / min, and operational stability such as stringing of hot melt adhesive is achieved.
○: There was no stringing and stable adhesion was possible.
×: There is stringing, the accuracy of the coating width is low, and there is a problem in terms of operational stability.
It was evaluated in two stages.

  From this result, as a hot melt adhesive, a melt viscosity at a temperature of 140 ° C. of 10,000 mPa · s or less, a melt viscosity at a temperature of 160 ° C. of 5000 mPa · s or less, and a loop tack adhesive strength of 2000 g / 25 mm or more is used. It can be seen that the desired result is obtained.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.

(Weight)
The basis weight is measured as follows. After the sample or test piece has been pre-dried, it is left in a test room or apparatus in a standard state (test location is temperature 20 ± 5 ° C., relative humidity 65% or less) to obtain a constant weight. Pre-drying refers to making a sample or test piece constant in an environment where the relative humidity is 10 to 25% and the temperature does not exceed 50 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. A sample with a size of 200 mm × 250 mm (± 2 mm) is cut out from the test piece in a constant weight using a rice-basis plate (200 mm × 250 mm, ± 2 mm). Measure the weight of the sample, multiply it by 20, calculate the weight per square meter, and use it as the basis weight.

(Thickness)
The thickness is automatically measured using an automatic thickness measuring instrument (KES-G5 handy compression measurement program) under the conditions of load: 0.098 N / cm ² and pressure area: 2 cm ² .

  The present invention is suitable for a pants-type disposable diaper as in the above example, but can be applied not only to a tape-type or pad-type disposable diaper but also to all absorbent articles such as sanitary napkins.

DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior body, 12A ... Side seal part, 12H ... 2nd sheet material, 12S ... 1st sheet material, 12r ... Folded part, 200 ... Interior body, 30 ... Top sheet, 40 ... Intermediate sheet, 50 ... absorbent element, 56 ... absorbent, 58 ... packaging sheet, 60 ... solid gather, 62 ... gather sheet, 70 ... continuous sheet joint , 71 ... adhesive, 80 ... wrinkle.

Claims (5)

Between the 1st sheet material, the 2nd sheet material which counters one side of this 1st sheet material, and these 1st sheet materials and the 2nd sheet material, an interval of 10 mm or less is mutually established along an expansion-contraction direction. A plurality of elongated elastic elastic members provided in a space;
Each of the first sheet material and the second sheet material has a thickness of 0.1 to 1 mm, a basis weight of 10 to 20 g / m ² , a bending resistance of 40 to 55 mm in the expansion / contraction direction, and a bending / softening direction orthogonal to the expansion / contraction direction. The degree of bending is 25 to 35 mm, and the bending resistance in the expansion / contraction direction is higher than the bending resistance in the direction orthogonal to the expansion / contraction direction,
The first sheet material and the second sheet material are arranged intermittently in the expansion / contraction direction, continuously in a direction intersecting with the expansion / contraction direction without having a portion that is not joined in either the expansion / contraction direction or the intersecting direction. And joined by an adhesive that intersects the plurality of elongated elastic stretch members, a continuous sheet joint is formed,
The elastic elastic member is fixed to at least one of the first sheet material and the second sheet material by an adhesive at a position intersecting the continuous sheet joining portion ;
The first sheet material and the second sheet material contract as the elastic expansion and contraction member contracts, so that the portions located between the continuous sheet joints in the first sheet material and the second sheet material swell in opposite directions. Each has a ridge,
The stretch rate of the elastic stretch member in a state where the stretch structure is fully deployed is 200 to 350%,
Expansion and contraction direction of the width of each successive sheet joined portion is 1 to 4 mm, the interval of the continuous sheet joints adjacent is 4 to 8 mm,
The first sheet material and the second sheet material are a nonwoven fabric of polypropylene or a copolymer thereof, or a nonwoven fabric of core-sheath fibers having polyethylene as a sheath and polypropylene as a core component,
An elastic structure of an absorbent article characterized by the above. The absorbent article includes an exterior body constituting a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior body, in both sides of the exterior body in the front body and in the back body A pants-type disposable in which both sides of the exterior body are joined to each other to form a side seal portion, so that the waistline portion is formed in an annular shape, and a waist opening and a pair of left and right leg openings are formed. A diaper,
The stretchable structure is provided in a region including at least both sides in the width direction of the interior body in the exterior body so that the elastic stretchable member is in the width direction.
The elastic structure of the absorbent article according to claim 1. When the region on both sides in the width direction of the interior body in the exterior body is divided into an end region on the interior body side, an end region on the side seal portion side, and an intermediate region located therebetween, the interior body side The absorbent article according to claim 2, wherein an interval between continuous sheet joint portions in at least one of an end region and an end region on the side seal portion side is narrower than an interval between continuous sheet joint portions in the intermediate region. Telescopic structure.   The stretchable structure of an absorbent article according to any one of claims 1 to 3, wherein an interval between the adjacent elastic stretchable members is 3 to 7 mm.   The adhesive is a hot-melt adhesive having a melt viscosity at a temperature of 140 ° C of 10,000 mPa · s or less, a melt viscosity at a temperature of 160 ° C of 5000 mPa · s or less, and a loop tack adhesive strength of 2000 g / 25 mm or more. The elastic structure of the absorbent article of any one of -4.