阅读说明：本技术 伸缩部件和具有该伸缩部件的一次性穿着物品 (Stretchable member and disposable wearing article having the same ) 是由 酒井俊辅 于 2018-09-25 设计创作，主要内容包括：本发明提供伸缩部件和具有该伸缩部件的一次性穿着物品,其中,收缩皱褶不单调而显示出复杂的外观,在将其应用于吸收性物品的情况下,针对消费者的吸引力优异。在相邻的第1接合部列(A1)与第2接合部列(A2)之间形成有第3接合部列(A3),所述第3接合部列(A3)的所述排列方向上的至少一部分的间隔(S3)比所述第1接合部列(A1)的间隔(S1)和第2接合部列(A2)的在所述排列方向上的所述间隔(S2)长。(The invention provides a stretchable member and a disposable wearing article having the stretchable member, wherein the stretchable member shows a complicated appearance without monotonous contraction wrinkles, and is excellent in consumer appeal when applied to an absorbent article. A3 rd joint row (A3) is formed between adjacent 1 st joint row (a1) and 2 nd joint row (a2), and an interval (S3) of at least a part of the 3 rd joint row (A3) in the arrangement direction is longer than an interval (S1) of the 1 st joint row (a1) and the interval (S2) of the 2 nd joint row (a2) in the arrangement direction.)

1. A telescopic member, characterized in that,

the telescopic member has a telescopic structure of the elastic piece as follows: the elastic sheet is interposed between a1 st sheet having air permeability and a2 nd sheet having air permeability, the 1 st sheet and the 2 nd sheet being joined together through a joining hole penetrating the elastic sheet or being joined together across the elastic sheet at a plurality of sheet joining parts arranged at intervals,

it is shown that the stretching region of the elastic sheet stretching structure can be stretched in the stretching direction by the stretching force of the elastic sheet,

the telescopic member is formed with a joint line in which the joints are spaced apart from each other in an arrangement direction intersecting with a telescopic direction,

a plurality of the joint rows are formed at intervals in the expansion and contraction direction,

a3 rd joint line is formed between the adjacent 1 st joint line and the 2 nd joint line,

the interval of at least a part of the 3 rd joint line in the arrangement direction is longer than the interval of the 1 st joint line and the 2 nd joint line on both sides of the 3 rd joint line in the arrangement direction.

2. The telescopic member of claim 1,

the crossing angle between the arrangement direction and the stretching direction is 45-135 degrees.

3. The telescopic member of claim 1 or 2,

the joint portion of the 3 rd joint portion row forms a cross row aligned in a direction crossing the joint portion row group together with the joint portion of the 1 st joint portion row and the joint portion of the 2 nd joint portion row adjacent to each other.

4. The telescopic member of claim 3,

the cross rows are formed in a plurality of rows at intervals in the arrangement direction.

5. A pants-type disposable wearing article having an extensible member according to any one of claims 1 to 3, comprising: an integral outer covering body extending from the front body part to the rear body part or outer covering bodies respectively provided on the front body part and the rear body part; an inner body attached to a widthwise middle portion of the outer body and extending over front and rear sides of the crotch portion; side seal parts formed by respectively joining two side parts of the outer packaging body in the front body part and two side parts of the outer packaging body in the back body part; and a waist opening and a pair of left and right leg openings, wherein,

the elastic member is provided in the outer covering of at least one of the front body portion and the rear body portion over a width direction range corresponding to the side seal portion in at least a part of a range in the front-rear direction, and an expansion/contraction direction of the elastic member is a width direction.

Technical Field

The present invention relates to a stretchable member having a stretchable structure in which an elastic sheet such as an elastic sheet is sandwiched between a1 st sheet layer and a2 nd sheet layer, and a disposable wearing article having the stretchable member.

Background

In disposable wearing articles such as disposable diapers, in order to improve the fit to the body surface, stretchability is generally imparted to appropriate portions such as leg circumferences and waist circumferences. As a method for imparting stretchability, conventionally, a method has been widely used in which an elongated elastic member such as a rubber thread is attached in an elongated state in the longitudinal direction thereof, but when it is desired to impart stretchability with a certain width, such a method is adopted: the rubber wires are fixed in a state of being arranged side by side with a space in the width. As another invention of the present applicant, the following method has been proposed as a means for further improving the fit of the surface: the elastic sheet is attached in a state of being stretched in a direction in which stretchability is imparted. (see, for example, patent document 1 and patent document 2).

In this elastic film-based stretchable structure (hereinafter, also referred to as an elastic sheet stretchable structure), the stretchable region is formed by laminating an elastic film between a1 st sheet layer made of nonwoven fabric and a2 nd sheet layer made of nonwoven fabric, and the 1 st sheet layer and the 2 nd sheet layer are joined together through joining holes penetrating the elastic film at a plurality of dot-like sheet joining portions arranged at intervals in a stretchable direction and a direction perpendicular to the stretchable direction, respectively, in a state where the elastic film is stretched in the stretchable direction along the surface thereof.

In such an elastic sheet stretchable structure, since the elastic film is contracted between the sheet joining portions in a natural length state, the interval of the sheet joining portions is narrowed, and contracted wrinkles extending in a direction intersecting the stretching direction are formed between the sheet joining portions on the 1 st sheet layer and the 2 nd sheet layer.

When oppositely stretched, the spacing of the panel joints and the contracted gathers on the 1 st and 2 nd sheet layers expand as the elastic film stretches between the panel joints, being elastically stretchable to the fully unfolded state of the 1 st and 2 nd sheet layers. The elastic piece telescopic structure has the following advantages: the elastic film is excellent in the fit of the surface, and since the 1 st sheet layer and the 2 nd sheet layer are not joined to the passing surface of the elastic film and the number of the joints between the 1 st sheet layer and the 2 nd sheet layer is extremely small, the elastic film is very flexible, and the joint holes of the elastic film contribute to the improvement of the air permeability in the thickness direction.

However, if the shrinkage creases are continued for a long time, the appearance is observed to be the same appearance in which the shrinkage creases are repeated in a wavy manner in one direction, so that the appearance is monotonous, and the product lacks appeal to consumers.

Disclosure of Invention

Problems to be solved by the invention

Accordingly, a main object of the present invention is to provide a telescopic member: the shrinkage wrinkles are not monotonous and show a complicated appearance, and when the shrinkage wrinkles are applied to an absorbent article, the attractiveness to consumers is excellent.

Means for solving the problems

In the extensible member according to the present invention to solve the above problems, the extensible member includes an elastic piece extensible structure including: the elastic sheet is interposed between a1 st sheet layer having air permeability and a2 nd sheet layer having air permeability, the 1 st sheet layer and the 2 nd sheet layer are joined together through a joining hole penetrating the elastic sheet at a plurality of sheet joining portions formed at intervals or joined together with the elastic sheet therebetween, a stretching region exhibiting a stretching structure of the elastic sheet is stretchable in a stretching direction by a stretching force of the elastic sheet, the stretching member is formed with joining portion rows in which the joining portions are formed at intervals in an arrangement direction intersecting the stretching direction, the plurality of joining portion rows are formed at intervals in the stretching direction, a3 rd joining portion row is formed between adjacent 1 st joining portion rows and 2 nd joining portion rows, and the interval of at least a part of the 3 rd joining portion row in the arrangement direction is longer than the interval of the 1 st joining portion row and the 2 nd joining portion row on both sides of the 3 rd joining portion row in the arrangement direction.

If the interval of at least a part of the 3 rd joint line in the arrangement direction is longer than the interval of the 1 st joint line and the 2 nd joint line on both sides of the 3 rd joint line in the arrangement direction, a contraction wrinkle having a limited length can be formed between the 1 st joint line and the 2 nd joint line throughout the joints and joints of the 3 rd joint line.

If the 3 rd joint is not present, the contracted wrinkles formed between the 1 st joint line and the 2 nd joint line as a whole become long wrinkle-like contracted wrinkles (hereinafter, also referred to as "inter-line continuous wrinkles"), and the inter-line continuous wrinkles become wavy in the expansion and contraction direction, resulting in a monotonous appearance.

In contrast, the contracted wrinkles generated according to the present invention are contracted wrinkles having a limited length over the joints and joints in the 3 rd joint row, and are not contracted wrinkles continuous in the entire arrangement direction, and therefore, the contracted wrinkles appear scattered in the stretching direction and the arrangement direction, and thus the appearance is excellent.

In other words, the shrinkage wrinkles do not become monotonous and show a complicated appearance, and when the absorbent article is applied, the consumer-oriented appeal is excellent.

The angle at which the arrangement direction intersects with the expansion direction may be 45 to 135 degrees.

By maintaining the angle of intersection, when applied to an absorbent article, the contracted wrinkles can be caused to appear in an oblique direction, rather than being aligned in the front-rear direction, and a special appearance different from a configuration in which the contracted wrinkles appear in the front-rear direction by arranging the rubber string group in the width direction of the absorbent article can be caused to appear, for example, so that the attractiveness to the consumer is excellent.

Embodiments can be provided in which: the joint portion of the 3 rd joint portion row forms a cross row aligned in a direction crossing the joint portion row group together with the joint portion of the 1 st joint portion row and the joint portion of the 2 nd joint portion row adjacent to each other.

Shrinkage creases in the arrangement direction are formed on both sides of the joint row. In contrast, the contracted wrinkles in the arrangement direction and the contracted wrinkles in the arrangement direction are a joint line. If the rows of joints between the contracted pleats are continuous throughout the arrangement direction, the air-permeable path is entirely linear.

However, when the absorbent article is worn by a wearer, the contact manner (for example, strong contact or weak contact) in which the skin of the wearer contacts the stretchable region may be different, and in such a case, the local ventilation path may be insufficient.

On the other hand, when the 3 rd joint line is formed, a ventilation path along the 3 rd joint line is formed, and a ventilation path in the arrangement direction communicates with a ventilation path in a direction crossing the joint line group to form a mesh-like ventilation path.

The form may be such that: the cross rows are formed in a plurality of rows at intervals in the arrangement direction.

The shrinkage wrinkles in the alignment direction and the interruptions of the shrinkage wrinkles are clear as an appearance, so that the design pattern becomes clear.

In addition, there is an advantage that the ventilation path can be sufficiently ensured.

A pants-type disposable wearing article having an extensible member, characterized by comprising the extensible member according to any one of claims 1 to 3, and comprising: an integral outer covering body extending from the front body part to the rear body part or outer covering bodies respectively provided on the front body part and the rear body part; an inner body attached to a widthwise middle portion of the outer body and extending over front and rear sides of the crotch portion; side seal parts formed by respectively joining two side parts of the outer packaging body in the front body part and two side parts of the outer packaging body in the back body part; and a waist opening and a pair of left and right leg openings, wherein the elastic member is provided in the outer covering of at least one of the front body portion and the rear body portion over a width direction range corresponding to a space between the side seals in at least a part of a range in the front-rear direction, and the elastic member extends and contracts in the width direction.

If the stretchable member is applied to an outer body of a pants-type disposable wearing article, the advantage in appearance obtained by the present invention can be fully exerted.

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, according to the present invention, the contraction wrinkles do not become monotonous and show a complicated appearance, and when the contraction wrinkles are applied to an absorbent article, the attractiveness to consumers is excellent.

Drawings

Fig. 1 is a plan view (inner surface side) of a pants-type disposable diaper in an unfolded state.

Fig. 2 is a plan view (outer surface side) of the pants-type disposable diaper in an unfolded state.

Fig. 3 is a plan view showing only important parts of the pants-type disposable diaper in an unfolded state.

Fig. 4 (a) is a sectional view taken along line C-C of fig. 1, and fig. 4 (b) is a sectional view taken along line E-E of fig. 1.

Fig. 5 is a sectional view taken along line a-a in fig. 1.

Fig. 6 is a sectional view taken along line B-B in fig. 1.

Fig. 7 is a plan view of an important part (inner surface side) of the stretchable region in the pants-type disposable diaper in the unfolded state.

Fig. 8 (a) is a sectional view corresponding to the line C-C in fig. 1, and fig. 8 (b) is a sectional view corresponding to the line E-E in fig. 1.

Fig. 9 is a plan view and a sectional view showing an arrangement of the joint portions disclosed in patent document 1.

Fig. 10 is a plan view showing the arrangement of the joint portions disclosed in patent document 2.

Fig. 11 is a plan view showing an arrangement of the joint portions as a reference example for explanation.

Fig. 12 is a view showing the 1 st embodiment of the joint arrangement of the present invention.

Fig. 13 is a plan view showing the 2 nd embodiment of the joint arrangement of the present invention.

Fig. 14 is a plan view showing the 3 rd embodiment of the joint arrangement of the present invention.

Fig. 15 is a plan view showing the 4 th embodiment of the joint arrangement of the present invention.

Fig. 16 is a plan view showing a 5 th embodiment of the joint arrangement of the present invention.

Fig. 17 is a plan view showing embodiment 6 of the joint arrangement of the present invention.

Fig. 18 is a plan view showing embodiment 7 of the joint arrangement of the present invention.

Fig. 19 is a plan view showing an 8 th embodiment of the joint arrangement of the present invention.

Fig. 20 is a plan view showing a 9 th embodiment of the joint arrangement of the present invention.

Fig. 21 is a plan view showing a 10 th embodiment of the joint arrangement of the present invention.

Fig. 22 is a plan view showing an 11 th embodiment of the joint arrangement of the present invention.

Fig. 23 is a plan view showing a 12 th embodiment of the joint arrangement of the present invention.

Fig. 24 is a plan view showing a 13 th embodiment of the joint arrangement of the present invention.

Fig. 25 is a plan view showing a 14 th embodiment of the joint arrangement of the present invention.

Fig. 26 is a plan view showing an example of a joining mode at the joint portion.

Fig. 27 is a sectional view for explanation showing an example of the joining mode.

Fig. 28 is a sectional view for explanation showing an example of the joined state.

Fig. 29 is a plan view showing an example of the joined state.

Fig. 30 is a schematic view of an ultrasonic sealing device for manufacturing the telescopic member.

Detailed Description

An embodiment of the present invention will be described in detail below with reference to the drawings. The dotted portions in the cross-sectional view represent joining means such as a hot-melt adhesive.

Fig. 1 to 6 show a pants-type disposable diaper as an example of a disposable wearing article of the present invention. Reference numeral LD (longitudinal direction) denotes a front-rear direction, and WD denotes a width direction.

The pants-type disposable diaper (hereinafter, simply referred to as a diaper) includes: an outer body 20 that constitutes a front body portion F and a rear body portion B; and an inner body 10 integrally fixed to the inner surface of the outer body 20, wherein the inner body 10 is formed by interposing an absorber 13 between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. In the production, after the back surface of the interior body 10 is joined to the inner surface (upper surface) of the exterior body 20 by joining means such as a hot melt adhesive, the interior body 10 and the exterior body 20 are folded at the boundary between the front body portion F and the rear body portion B, i.e., at the center in the front-rear direction LD (longitudinal direction), and both side portions thereof are joined to each other by hot melt bonding or a hot melt adhesive to form the side seals 21, thereby forming a pants-type disposable diaper having a waist opening and a pair of left and right leg openings.

(structural example of inner body)

As shown in fig. 4 to 6, the interior body 10 has a structure in which an absorbent body 13 is interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12 made of polyethylene or the like, and absorbs and holds excreta liquid that has passed through the top sheet 11. The planar shape of the interior body 10 is not particularly limited, but is generally set to be substantially rectangular as shown in fig. 1.

As the liquid-permeable top sheet 11 covering the front side (skin side) of the absorbent body 13, a nonwoven fabric with or without holes, a porous plastic sheet, or the like is preferably used. As the face fabric fibers constituting the nonwoven fabric, there can be used not only synthetic fibers such as olefin-based fibers such as polyethylene and polypropylene, polyester-based fibers and polyamide-based fibers, but also regenerated fibers such as rayon and cuprammonium fibers and natural fibers such as cotton, and nonwoven fabrics obtained by an appropriate processing method such as spunlace, spunbond, hot-roll, melt-blown, and needle-punching can be used. Among these processing methods, the water-jet method is excellent in rich flexibility and drapability, and the hot rolling method is excellent in bulkiness and softness. When a plurality of through holes are formed in the liquid-permeable top sheet 11, urine and the like are quickly absorbed, and the dryness is excellent. The liquid-permeable top sheet 11 wraps around the side edge of the absorbent body 13 and extends to the back side of the absorbent body 13.

As the liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene can be used, but in recent years, a sheet having moisture permeability is preferably used from the viewpoint of prevention of stuffiness and wetness. The water-blocking/moisture-permeable sheet is a microporous sheet obtained by the following method: the inorganic filler is melt-kneaded in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretched in a uniaxial or biaxial direction.

As the absorbent body 13, a known material can be used, and for example, a material mainly composed of a stacked body of pulp fibers, an aggregate of filaments such as cellulose acetate, or a nonwoven fabric, and a super absorbent polymer or the like is mixed and fixed as necessary. The absorbent body 13 may be wrapped with a wrapping sheet 14 having liquid permeability and liquid retentivity, such as crepe paper, as necessary in consideration of the shape, the retention of the polymer, and the like.

The absorber 13 is formed in a substantially hourglass shape having a narrowed portion 13N in the crotch portion, the narrowed portion having a width narrower than the front and rear sides. The dimension of the narrowed portion 13N may be determined as appropriate, and the longitudinal length of the narrowed portion 13N may be set to about 20 to 50% of the entire length of the diaper, and the width of the narrowest portion thereof may be set to about 40 to 60% of the entire width of the absorber 13. In the case of having such a narrowed portion 13N, if the planar shape of the interior body 10 is formed in a substantially rectangular shape, an absorbent-free side portion 17 having no absorbent body 13 is formed in a portion of the interior body 10 corresponding to the narrowed portion 13N of the absorbent body 13.

The liquid-impermeable sheet 12 is folded back toward the back surface side on both sides in the width direction of the absorbent body 13 together with the liquid-permeable top sheet 11. As the liquid-impermeable sheet 12, an opaque sheet is preferably used so as not to show the brown color of feces, urine, or the like. As the sheet to be opacified, a sheet obtained by adding a pigment or filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc, barium sulfate to a plastic and making a film is preferably used.

Three-dimensional gather portions 90 suitable for leg gathers are formed on both side portions of the interior body 10. As shown in fig. 5 and 6, the three-dimensional gather portion 90 includes: a fixing portion 91 fixed to a side portion of the back surface of the interior body 10; a body portion 92 extending from the fixing portion 91 to the upper side of the front side of the interior body 10 through the side of the interior body 10; a folded portion 93 formed by fixing the front and rear end portions of the main body 92 to the side portions of the front surface (the top sheet 11 in the illustrated embodiment) of the interior body 10 in a folded state; and a free portion 94 formed without fixing the falling portions 93 to each other. Each of the above portions is formed by a gather sheet 95 formed by folding back a sheet of nonwoven fabric or the like into a double-layer sheet. The gather sheet 95 is attached to the entire front-rear direction of the inner body 10, the lying portions 93 are provided at the front and rear sides of the non-absorbent body side portion 17, and the free portions 94 extend to the front and rear sides of the non-absorbent body side portion 17. Further, between the double-layered gather sheets 95, an elongated gather portion elastic member 96 is disposed at a terminal portion of a free portion or the like. The gather elastic member 96 is used to raise the free portion 94 by an elastic stretching force in the product state as shown in fig. 5.

In the form shown in fig. 5 and 6, the gather portion elastic member 96 is adhesively fixed to the gather sheet 95 with the hot melt adhesive at the position of the gather portion elastic member 96 and the facing surfaces of the gather sheet 95 are joined together, except for the laid-down non-stretchable portion 97, but in the laid-down non-stretchable portion 97, there is no hot melt adhesive at the position of the gather portion elastic member 96, and therefore, the gather portion elastic member 96 and the gather sheet 95 are not bonded together and the facing surfaces of the gather sheet 95 are not joined together at the position having the gather portion elastic member 96.

The three-dimensional gather portion 90 shown in fig. 5 and 6 is in a form in which the main body portion 92 is not folded back.

As the gather portion elastic member 96, a material such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene polymer, silicone, polyester, or the like, which is generally used, can be used. In addition, in order to be not easily seen from the outside, it is preferable to arrange: the thickness is less than 925dtex, the tension is 150-350%, and the interval is less than 7.0 mm. The gather portion elastic member 96 may be a belt-like member having a certain width, in addition to a linear member in the illustrated form.

The face fabric constituting the gather sheet 95 is also similar to the liquid-permeable top sheet 11, and may be made of synthetic fibers such as olefin-based fibers, polyester-based fibers, and polyamide-based fibers, such as polyethylene and polypropylene, regenerated fibers such as rayon and cuprammonium fibers, and natural fibers such as cotton, and may be made of a nonwoven fabric obtained by an appropriate processing method such as a spunbond method, a hot-roll method, a melt-blown method, and a needle-punching method. In addition, for the gather sheet 95, in order to prevent permeation of urine and the like, and to prevent rash and improve the touch (dry feeling) of the skin, it is desirable to use a water repellent treated nonwoven fabric coated with a silicone-based, paraffin metal-based, alkyl chromium chloride-based water repellent agent or the like.

As shown in fig. 3 to 6, the back surface of the interior body 10 is joined to the inner surface of the exterior body 20 in the inner and outer fixing regions 10B (hatched regions) by a hot melt adhesive or the like. The inner and outer fixing regions 10B may be appropriately determined and may be provided almost entirely in the width direction WD of the inner body 10, but are preferably: both ends in the width direction are not fixed to the exterior body 20.

(construction example of outer body)

The outer package 20 extends outward beyond the side edge of the absorbent body 13. As shown in the figure, the side edge of the exterior body 20 may be positioned on the center side in the width direction of the side edge of the interior body 10 in the crotch portion, or the side edge of the exterior body 20 may be positioned on the outer side in the width direction of the side edge of the interior body 10 in the crotch portion. Further, the exterior body 20 includes: a waist portion T which is a front-rear direction range corresponding to the side seal portions 21; and an intermediate portion L that is a longitudinal range between the waist portion T of the front body portion F and the waist portion T of the rear body portion B.

In the exterior body 20 of the illustrated embodiment, an elastic sheet, for example, an elastic film 30 is interposed between the 1 st sheet layer 20A and the 2 nd sheet layer 20B as shown in fig. 2 and fig. 4 to 6 except for the middle portion L in the front-rear direction, and the elastic sheet stretch structure 20X is formed as shown in fig. 9 as follows: the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined together through the joining holes 31 penetrating the elastic film 30 at a plurality of sheet joining parts 40 arranged at intervals.

In the form applied to the diaper, the elastic sheet (elastic film 30 in the example of fig. 9) is stretched in the direction ED corresponding to the width direction WD of the diaper.

The 1 st sheet layer 20A and the 2 nd sheet layer 20B may be indirectly joined together via the elastic film 30 without passing through the joining hole 31 of the elastic film 30. The planar shape of the exterior body 20 is formed by concave leg girth lines 29 so that both side edges in the width direction of the middle portion L are formed with leg openings, and is formed into a shape resembling an hourglass as a whole. The exterior body 20 may be configured to: the outer cover 20 is formed in each of the front body portion F and the back body portion B, and is separated in the front-back direction LD of the diaper between the crotch portions.

The form shown in fig. 1 and 2 is a form in which the elastic sheet stretchable structure 20X extends to the waist end portion 23, but if the elastic sheet stretchable structure 20X is used for the waist end portion 23, the fastening of the waist end portion 23 becomes insufficient, and therefore, as shown in fig. 7 and 8, the conventional stretchable structure based on the elongated waist elastic member 24 may be provided instead of the elastic sheet stretchable structure 20X in the waist end portion 23 as needed. The waist elastic member 24 is a plurality of elongated elastic members such as rubber threads disposed at intervals in the front-rear direction LD, and provides a stretching force to fasten the waist of the body. The waist elastic members 24 are not substantially arranged in a bundle at a close interval, but are arranged at intervals of 3 or more, preferably 5 or more, at intervals of about 3 to 8mm in the front-rear direction so as to form a predetermined stretchable region. The elongation at the time of fixing the waist elastic member 24 may be appropriately determined, but in the case of a normal adult, it may be set to about 230 to 320%. The waist elastic member 24 is formed of rubber threads in the illustrated example, but other elongated elastic members such as flat rubber may be used. Although not shown, it may be: an elastic film 30 is provided at the waist end portion 23, and an elongated waist elastic member 24 is provided at a position overlapping the elastic film 30, thereby forming an extensible structure based on both elastic members. In the illustrated embodiment, the elongated elastic member extending along the leg opening is not provided at the edge portion of the leg opening in the outer casing 20, but the elongated elastic member may be provided at a position overlapping the elastic film 30 at the edge portion, or the elongated elastic member may be provided instead of the elastic film 30 at the edge portion.

As another embodiment, although not shown, the following modifications may be made as appropriate: the elastic sheet stretchable structure 20X is not provided in the intermediate portion L between the waist portion T of the front body portion F and the waist portion T of the back body portion B, or the elastic sheet stretchable structure 20X is provided continuously in the front-rear direction LD from the inside of the waist portion T of the front body portion F to the inside of the waist portion T of the back body portion B through the intermediate portion L, or the elastic sheet stretchable structure 20X is provided only in one of the front body portion F and the back body portion B.

(form of joint part)

In the present invention, the arrangement of the joint portion is characterized. In order to make this feature clear, the arrangement of the joint portions of the conventional example will be specifically described in advance.

Fig. 9 shows a typical example of the method disclosed in patent document 1.

That is, the group of joints 40 is arranged in a staggered manner, the joints 40 are elongated in the direction perpendicular to the expansion and contraction direction, and are formed in a symmetrical shape (symmetrical in the left-right direction in fig. 9 (a)) about a center line passing through the center in the expansion and contraction direction, the width 40x of the joints 40 in the expansion and contraction direction is preferably 0.2 to 0.4mm, the interval d1 of the joints 40 arranged in the expansion and contraction direction is preferably 3 to 12.9mm, more preferably 5 to 6.4mm, and the interval d2 of the joints 40 arranged in the direction perpendicular to the expansion and contraction direction is preferably 2 to 10.5mm, more preferably 2.3 to 4.6 mm.

As described above, the joint portions 40 having the significantly narrow width 40x in the stretching direction are arranged in a staggered manner at the large separation intervals d1 to some extent in the stretching direction, and the contraction force of the elastic film 30 directly acts on the joint portions 40, so that the arrangement and the intervals of the joint portions 40 are reliably maintained at the positions of the joint holes 31 of the elastic film 30, and as a result, the flexibility is not easily lowered. In addition, the fold 25f extends almost straight in the direction perpendicular to the retracting direction, and the engaging portion 40 is hidden and inconspicuous between the fold 25f and the fold 25 f. Therefore, the elastic sheet stretch structure 20X is formed so that the appearance is closer to the cloth while the decrease in flexibility is suppressed.

On the other hand, when the engaging portion 40 is arranged in a staggered manner but the shape of the engaging portion 40 is circular, the engaging portion 40 is clearly seen between the folds 25f and 25f of the wrinkles, and the folds 25f extend in a direction perpendicular to the stretching direction so as to greatly bypass the engaging portion 40, so that the wavy folds 25f are formed as a whole, and the cloth-like appearance tends to be unable to be obtained.

From such a viewpoint, it is desirable that the shape of the joint portion 40 is elongated in a direction perpendicular to the expansion and contraction direction. However, if the maximum length of the joint portion 40 in the direction perpendicular to the expansion and contraction direction is too short or too long, there is a concern that: the linearity of the fold 25f is reduced or the flexibility is reduced. Therefore, although these dimensions can be determined appropriately, the length 40y of the joint 40 in the direction perpendicular to the expansion/contraction direction is preferably 0.4 to 3.2mm, and particularly preferably 0.7 to 1.4 mm.

On the other hand, in patent document 2, in 2 examples shown in fig. 10 (a) and (b), the openings (shown in a slightly vertically long rectangle) of the stretchable film are arranged in a staggered manner, and in the example (b), the small circular auxiliary bonding portions are arranged between the rectangular main openings. In the example (b), the idea of the staggered arrangement is also used.

The arrangement and size of the openings are within the size range (unit is mm.) shown in fig. 10, which is preferable mainly in terms of appearance, texture, air permeability, and the like.

Both inventions of patent documents 1 and 2 disclose elongated openings and show a staggered arrangement.

However, in the conventional example, since the separation interval between the openings of the elastic film in the direction perpendicular to the stretching direction is set to be large, the stretching stress in the stretching direction is high, and there are many wearers who feel excessively (in the width direction) strongly fastened, for example, when applied to a pants-type disposable diaper.

Here, the opening length B is set to 0.3 to 0.7mm, and the separation distance H is set to 0.6 to 1.4 mm.

In contrast, the present inventors found that: when the separation interval between the openings of the elastic film is set small in the direction perpendicular to the stretching direction (in the figure, the vertical direction: the direction of reference numeral LD) as shown in fig. 11, the stretching stress in the stretching direction can be reduced, and therefore, when applied to a pants-type disposable diaper, the disposable diaper can fit comfortably to the wearer with a weak fastening force.

The reason is considered to be that: only by applying a small extension force in the width direction (the direction of expansion and contraction of the elastic film) from the outside, the opening portion opens in the width direction as shown in fig. 9 to become the engagement hole 31, whereas in the separation interval region between the opening portions perpendicular to the direction of expansion and contraction, even if the opening portion is extended in the width direction, the extension stress of the elastic film directly becomes a contraction force to fasten the wearer because the opening portion is not present.

The form shown in fig. 11 has an advantage that it can fit comfortably to the wearer and has excellent air permeability because the area ratio of the joint portion and the area ratio of the joint hole in the use state of being extended in the width direction are high.

In the use form of the product of the embodiment shown in fig. 11 (a), however, wrinkles along the arrangement direction (vertical direction) LD are formed in the separation region between the row of the joint portions 40 and 40 … along the vertical direction LD and the adjacent row of the joint portions 40 and 40 … separated from the row along the expansion direction ED (width direction). As shown in fig. 11 (b), the wrinkles 25F have a similar mountain shape. That is, patent document 1 shows that the cross section is different from the cross section shown in fig. 9 (c).

In the case of using the form shown in fig. 11 as the entire stretch region of the product and from the viewpoint of design, the design is often simple, and the product is not attractive, except that the wrinkles 25F (inter-row continuous wrinkles) long in the arrangement direction LD are formed repeatedly in the stretch direction ED (width direction) in the same manner.

The present invention includes the 1 st joint part and the 2 nd joint part, specifically, the structures described in the claims, and includes various forms, and also includes combinations of the various forms.

For reasons of space, the following description will proceed with reference to representative examples.

Fig. 12 to 25 show the arrangement of the joint 40 between the 1 st sheet 20A and the 2 nd sheet 20B, and the contraction wrinkles generated by the contraction of the elastic sheet, for example, the elastic film 30 are indicated by reference numeral 26. The shape of the joint 40 can be appropriately selected, and a rectangular shape is exemplified.

In addition, the ventilation path is shown by reference PW (broken line path).

< embodiment 1 >

The stretchable member of embodiment 1 shown in fig. 12 includes the following stretchable structure of the elastic sheet: the elastic sheet (not shown) is interposed between a1 st sheet (not shown) having air permeability and a2 nd sheet (not shown) having air permeability, and the 1 st sheet and the 2 nd sheet are joined together at a plurality of sheet joining portions 40 arranged at intervals through a joining hole (not shown) penetrating the elastic sheet or joined together through the elastic sheet.

In addition, the expansion region showing the expansion structure of the elastic piece is capable of expanding and contracting in the expansion direction by the expansion force of the elastic piece.

In the present invention, a joint line (aligned vertically in the example of fig. 12) is formed in which the joints 40 are spaced apart from each other in an arrangement direction intersecting with the expansion and contraction direction (perpendicularly intersecting with each other in the example of fig. 12).

In fig. 12, A3 rd joint row A3 is formed between the adjacent 1 st joint row a1 and 2 nd joint row a2, and the interval S3 of at least a part of the 3 rd joint row A3 in the arrangement direction is longer than the intervals S1, S2 in the arrangement direction of the 1 st joint row a1 and the 2 nd joint row a2 on both sides of the 3 rd joint row A3.

In this embodiment, the contracted wrinkles 26 having a limited length can be formed between the 1 st joint row a1 and the 2 nd joint row a2 over the joints 40 and joints 40 of the 3 rd joint row A3.

If the 3 rd joint 40 is not present, as shown in fig. 11, the contracted wrinkles generated in the whole between the 1 st joint line a1 and the 2 nd joint line a2 become long wrinkle-like contracted wrinkles, that is, inter-row continuous wrinkles, and the inter-row continuous wrinkles become wavy in the expansion and contraction direction, and the appearance is monotonous.

In contrast, the contracted wrinkles 26 generated according to the present invention are contracted wrinkles 26 having a limited length between the 1 st joint line a1 and the 2 nd joint line a2 over the joints 40 and joints 40 of the 3 rd joint line A3, and are not contracted wrinkles 26 that are continuous in the entire arrangement direction, and therefore, the contracted wrinkles 26 are scattered in the stretching direction and the arrangement direction, and thus the appearance is excellent.

In other words, the contraction wrinkles 26 do not monotonously exhibit a complicated appearance, and when applied to an absorbent article, the attractiveness to the consumer is excellent.

As in the example of fig. 25 described later: the arrangement direction and the expansion/contraction direction ed (wd) are not perpendicular, but intersect each other at an intersection angle θ of, for example, 45 degrees to 135 degrees.

By maintaining the angle of intersection, when applied to an absorbent article, the contracted wrinkles 26 can be caused to appear in an oblique direction, rather than being arranged in the front-rear direction, and a special appearance different from a conventional form in which contracted wrinkles appear in the front-rear direction by arranging a rubber string group in the width direction of the absorbent article can be caused to appear, for example, and the attractiveness to consumers can be improved.

On the other hand, as shown in fig. 12, an embodiment can be provided in which: the joint 40 of the 3 rd joint row forms a crossing row X aligned in a direction crossing the joint row group together with the joint 40 of the 1 st joint a1 row and the joint 40 of the 2 nd joint row adjacent to each other.

Contraction wrinkles 26 in the arrangement direction are formed on both sides of the joint row. In contrast, there is a joint line between the contracted wrinkles 26 in the arrangement direction and the contracted wrinkles 26 in the arrangement direction. If the row of joints between the contracted wrinkles 26, 26 is continuous in the entire arrangement direction, the air-permeable path is straight as a whole.

However, when the absorbent article is worn by a wearer, the contact manner (for example, strong contact or weak contact) in which the skin of the wearer contacts the stretchable region may be different, and in such a case, the local ventilation path may be insufficient.

On the other hand, when the 3 rd joint row A3 is formed, the air passage PW is formed along the joint 40 of the 3 rd joint row A3, and the air passage PW in the arrangement direction communicates with the air passage PW in the direction crossing the joint row group to form the mesh air passage PW, and as a result, the stuffy wet discharged from the wearer can be exhausted through the mesh air passage PW.

< embodiment 2 >

In the embodiment shown in fig. 13, this is an example: the shape and size of the joint 40 of the 1 st joint a1 row and the joint 40 of the 2 nd joint row are different, and the intervals S1 and S2 are different.

< embodiment 3 >

In the embodiment shown in fig. 14, this is done: the joint 40 of the 3 rd joint row forms a crossing row X aligned in a direction crossing the joint row group together with the joint 40 of the 1 st joint a1 row and the joint 40 of the 2 nd joint row adjacent to each other. In particular, 2 intersecting rows X are formed. The width (vertical width in the illustrated example) of the ventilation path PW is larger than that in example 1, and the ventilation performance is improved.

< example 4 >

In the embodiment shown in fig. 15, this is an example: the formation of the contracted wrinkles 26 is formed to be different in position in the front-rear direction. This is complicated and not monotonous in design, and can give a sense of high quality. In addition, the ventilation path PW is formed in a step shape.

< embodiment 5 >

In the embodiment shown in fig. 16, this is an example: as for the generation of the shrinkage wrinkles 26, it is formed in a corrugated shape as a whole. This can give a sense of jump in design rather than monotony. In addition, the ventilation path PW is formed in a corrugated shape.

< embodiment 6 >

In the embodiment shown in fig. 17, this is an example: as for the generation of the shrinkage wrinkles 26, it is formed roughly in a hexagonal shape with corners slightly removed. This can become interesting in design rather than monotonous. In addition, the air-permeable path PW is formed in a honeycomb shape.

< embodiment 7 >

In the embodiment shown in fig. 18, this is an example: the contracted wrinkles 26 are formed in a more complicated vertically elongated shape. This can become interesting in design rather than monotonous. In addition, the ventilation path PW is formed in an angular corrugated shape.

< embodiment 8 >

In the embodiment shown in fig. 19, the example is an example in which the intersecting columns are inclined. The contraction fold 26 is formed in such a manner as to create an inclined rectangle. This can become interesting in design rather than monotonous.

< embodiment 9 >

In the embodiment shown in fig. 20, the presence of the joints 40, 40 of the 1 st joint row a1, as opposed to the example of fig. 18, creates an annular contracted crease 26. This can become interesting in design rather than monotonous. In addition, the ventilation path PW is formed in an angular corrugated shape.

< 10 th embodiment >

In the embodiment shown in fig. 21, the cross-column direction is inclined in the opposite direction to the example of fig. 20. The contraction fold 26 is formed in such a manner as to create an inclined rectangle. This can become interesting in design rather than monotonous.

< 11 th embodiment >

In the embodiment shown in fig. 22, this is an example: the intersecting columns are slanted in multiple columns (3 columns in the example of the figure). The contraction fold 26 is formed in such a manner as to create an inclined rectangle. This can become interesting in design rather than monotonous.

< embodiment 12 >

In the embodiment shown in fig. 23, shrinkage creases 26 of different sizes are generated. This can become interesting in design rather than monotonous.

< embodiment 13 >

In the embodiment shown in fig. 24, 3 shrinkage creases 26 of different sizes are generated. This can become interesting in design rather than monotonous.

< embodiment 14 >

In the above example, the arrangement direction is perpendicular to the expansion/contraction direction ed (wd), but as in the example of fig. 25: the alignment direction and the contraction direction ed (wd) are not perpendicular, but intersect each other at an intersection angle θ of, for example, 45 degrees to 135 degrees. This can become interesting in design rather than monotonous. The angle θ of intersection is preferably 50 degrees to 130 degrees, and particularly preferably 60 degrees to 120 degrees.

In the relation described in embodiment 14 shown in fig. 25, the joint line is not perpendicular to the contraction direction ed (wd) (i.e., θ is not 90 degrees), but is inclined, and the advantage of such an arrangement is not considered from the viewpoint of designing a pattern, but has another advantage. Next, the advantages thereof will be described.

That is, as is apparent from fig. 25, the separation distance between the joining portions 40, 40 can be increased on the vertical direction line. In the example of fig. 12, the separation interval between the engaging portions 40, 40 is very narrow in the 1 st engaging portion row a1 and the 2 nd engaging portion row a 2. As described above, it is desirable that the joining of the 1 st sheet layer 20A and the 2 nd sheet layer 20B at the sheet joining portion 40 is achieved by a joining means based on material fusion such as heat sealing or ultrasonic sealing.

In the case of continuous production, sealing fusion by ultrasonic waves is performed between the abutment roller and the ultrasonic horn, but it is important that the ultrasonic horn is brought into close contact with the sheet over the entire axial direction of the abutment roller in order to prevent energy loss, and therefore, in the case where a pattern having a large proportion of abutment roller convex portions is formed along a line of generating lines of line contact, such as the row of the joint portions 40 and 40 …, it is necessary to provide a large ultrasonic output, and therefore an excessively large close contact force acts along the generating lines of line contact, and in this case, the load on the equipment side is large.

In contrast, in the case of embodiment 14 shown in fig. 25 (in general, in the case of the inclined arrangement), the ratio of the joint portion on the line in the vertical direction is small, and a stable line pressure can be achieved, so that the equipment load is small, and a stable operation can be achieved.

The joint 40 is formed as follows: the length of the reference in the vertical direction is 0.3 to 7.0mm, preferably 0.5 to 5.0mm, and particularly preferably 0.7 to 2.5 mm. The width of the joint 40 is preferably 0.2 to 1.0 mm.

In addition, the engaging portions 40, 40 … are formed as follows: the formation pitch of ED standard in the expansion direction is 2.0-20.0 mm, preferably 2.0-15.0 mm, and particularly preferably 2.0-10.0 mm.

The percentage of the distance on the vertical direction basis determined by the mutual relationship between the adjacent joint portions 40, 40 in the row of joint portions 40, 40 …, (separation distance d between the adjacent joint portions 40, 40)/(distance from one point of the joint portion to the corresponding one point of the adjacent joint portion: pitch) is 5 to 60%, preferably 10 to 45%, and particularly preferably 20 to 35%.

If the percentage is too high, the stretching stress in the width direction (stretching direction) is high when the article is applied, and it is difficult to obtain a proper fit when the article is worn.

In addition, if the percentage is too low, the possibility that the joining portions 40, 40 adjacent in the vertical direction LD are mutually continuous in the manufacturing process cannot be excluded, and more fundamentally, the load on the equipment is excessively applied to the anvil and the heating horn that form the joining portions, thereby causing an obstacle to the stabilizing work.

Can be used.

As for the shape of each of the sheet engagement portions 40 and the engagement hole 31 in the natural length state, other than the above-described rectangular shape long in the vertical direction, it can be determined as appropriate. For example, as shown in fig. 26, the lens may be formed in any shape such as a perfect circle, a triangle, a polygon, a star, or a cloud, in addition to a convex lens shape (see fig. 26 (a)), a diamond shape (see fig. 26 (b)), a concave lens shape (see fig. 26 (c)), or an oval shape (see fig. 26 (d)).

The engagement hole 31 is mainly related to the shape and manufacturing stage of the engagement portion 40(41, 42, 43) or the degree of expansion and contraction.

In the case where the 1 st sheet layer 20A and the 2 nd sheet layer 20B in the sheet joint portion 40 are joined through the joining hole 31 formed in the elastic film 30, it is desirable that the 1 st sheet layer 20A and the 2 nd sheet layer 20B are not joined to the elastic film 30 at least except between the 1 st sheet layer 20A and the 2 nd sheet layer 20B in the sheet joint portion 40.

The joining means of the 1 st sheet layer 20A and the 2 nd sheet layer 20B in the sheet joining portion 40 is not particularly limited. For example, the 1 st sheet layer 20A and the 2 nd sheet layer 20B in the sheet joining portion 40 may be joined by a hot melt adhesive, or may be joined by a joining means based on material fusion such as heat sealing or ultrasonic sealing.

In the case where the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined through the joining holes 31 of the elastic film 30 in the sheet joint 40, the form in which the sheet joint 40 is formed by material fusion may be any one of the following forms, but the 2 nd and 3 rd fusion forms are preferable: a1 st fusion-bonded mode (see fig. 27 (a)) in which the 1 st sheet layer 20A and the 2 nd sheet layer 20B are bonded together only by the molten and cured product 20m of most or part of at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B in the sheet-bonded portion 40; a2 nd welding mode (see fig. 27 (B)) in which the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined together only by the melt-cured product 30m of all or most or part of the elastic film 30 in the sheet joint 40; and a3 rd welding mode (see fig. 27 (c)) in which the 1 st welding mode and the 2 nd welding mode are combined.

Particularly, the 1 st sheet layer 20A and the 2 nd sheet layer 20B are preferably joined together by the melt-cured product 20m of a part of the 1 st sheet layer 20A and the 2 nd sheet layer 20B and the melt-cured product 30m of the whole or most of the elastic film 30 in the sheet joined portion 40. In the 3 rd welding mode shown in fig. 29 (B), the molten cured product 30m of the elastic film 30 showing white is visible between the molten cured fiber products 20m of the 1 st sheet layer 20A or the 2 nd sheet layer 20B showing black, whereas in the 1 st welding mode shown in fig. 29 (a), the molten cured fiber products 20m of the 1 st sheet layer 20A or the 2 nd sheet layer 20B are not visible therebetween.

In the case where the 1 st sheet layer 20A and the 2 nd sheet layer 20B are bonded to each other with the most part or part of the melt-cured product 20m of at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B as the adhesive as in the 1 st bonding mode or the 3 rd bonding mode, the sheet bonded portion 40 is preferably not hardened because the 1 st sheet layer 20A and the 2 nd sheet layer 20B are not partially melted.

When the 1 st sheet layer 20A and the 2 nd sheet layer 20B are nonwoven fabrics, the following forms are included in the 1 st sheet layer 20A and the 2 nd sheet layer 20B without melting: the core (including not only the core in the composite fiber but also the central portion of the single component fiber) remains in the entire fiber of the sheet joint 40, but the peripheral portion (including not only the sheath in the composite fiber but also the surface layer side portion of the single component fiber) melts; alternatively, a part of the fibers is not melted at all but the remaining fibers are completely melted, or the core remains but its surrounding portion is melted.

When the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined together using the molten and cured product 30m of the elastic film 30 as an adhesive as in the 2 nd welding mode and the 3 rd welding mode, the peel strength is high. In the 2 nd welding mode, the welding can be produced by: under the condition that the melting point of at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B is higher than the melting point of the elastic film 30 and the heating temperature at the time of forming the sheet bonded portion 40, the elastic film 30 is sandwiched between the 1 st sheet layer 20A and the 2 nd sheet layer 20B, and the portion to be the sheet bonded portion 40 is pressurized and heated, so that only the elastic film 30 is melted.

On the other hand, in the 3 rd welding mode, the welding can be produced by: under the condition that the melting point of at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B is higher than the melting point of the elastic film 30, the elastic film 30 is sandwiched between the 1 st sheet layer 20A and the 2 nd sheet layer 20B, and the elastic film 30 and at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B are melted by applying pressure and heat to the portion to be the sheet joining portion 40.

From such a viewpoint, the melting point of the elastic film 30 is preferably about 80 to 145 ℃, the melting points of the 1 st and 2 nd sheet layers 20A and 20B are preferably about 85 to 190 ℃, particularly preferably about 150 to 190 ℃, and the difference between the melting points of the 1 st and 2 nd sheet layers 20A and 20B and the melting point of the elastic film 30 is preferably about 60 to 90 ℃. In addition, the heating temperature is preferably about 100 to 150 ℃.

In the 2 nd welding mode and the 3 rd welding mode, when the 1 st sheet 20A and the 2 nd sheet 20B are nonwoven fabrics, the melt-cured product 30m of the elastic film 30 may penetrate between the fibers over the entire thickness direction of the 1 st sheet 20A and the 2 nd sheet 20B at the sheet joint 40 as shown in fig. 28 (c), but the flexibility of the sheet joint 40 is high in a mode in which the fibers penetrate to the middle in the thickness direction as shown in fig. 28 (a) or in a mode in which the fibers hardly penetrate between the 1 st sheet 20A and the 2 nd sheet 20B as shown in fig. 28 (B).

Fig. 30 shows an example of an ultrasonic sealing device suitable for forming the 2 nd welding mode and the 3 rd welding mode. In this ultrasonic sealing device, when the sheet joint 40 is formed, the 1 st sheet layer 20A, the elastic film 30, and the 2 nd sheet layer 20B are fed between the anvil roll 60 and the ultrasonic horn 61, and the anvil roll 60 has, on the outer surface, the protrusions 60A formed in accordance with the pattern of the sheet joint 40. At this time, for example, by making the feeding and conveying speed of the upstream elastic film 30 by the feeding driving roller 63 and the nip roller 62 slower than the conveying speed after the support roller 60 and the ultrasonic horn 61, the elastic film 30 is elongated in the MD direction (machine direction, conveying direction) to a predetermined elongation on the path from the nip position by the feeding driving roller 63 and the nip roller 62 to the sealing position by the support roller 60 and the ultrasonic horn 61. The elongation of the elastic film 30 can be set by selecting the speed difference between the support roller 60 and the feeding drive roller 63, and can be set to about 300% to 500%, for example. And 62 is a nip roll.

The 1 st sheet layer 20A, the elastic film 30, and the 2 nd sheet layer 20B fed between the anvil roll 60 and the ultrasonic horn 61 are heated by ultrasonic vibration energy of the ultrasonic horn 61 while being pressed between the protrusion 60A and the ultrasonic horn 61 in a state of being laminated in this order, and only the elastic film 30 is melted or at least one of the 1 st sheet layer 20A and the 2 nd sheet layer 20B and the elastic film 30 are melted, whereby the joining holes 31 are formed in the elastic film 30 and the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined together through the joining holes 31. Therefore, in this case, the area ratio of the sheet joining portion 40 can be selected by selecting the size, shape, separation interval, arrangement pattern in the roller longitudinal direction and roller circumferential direction, and the like of the protruding portion 60a of the backup roller 60.

The reason for the formation of the engagement hole 31, although not necessarily clear, may be considered as: the portions of the elastic film 30 corresponding to the protrusions 60a of the backup roller 60 are melted and released from the surroundings, thereby forming holes. At this time, as shown in fig. 9 (a) and 11 (a), in the elastic film 30, the portions between the adjacent coupling holes 31 arranged in the expansion and contraction direction ED are cut off by the coupling holes 31 from the portions on both sides in the expansion and contraction direction, and the support on both sides in the contraction direction is lost, so that the coupling holes 31 expand in the expansion and contraction direction ED as the center side in the direction LD perpendicular to the expansion and contraction direction is contracted to the balance as the center side in the expansion and contraction direction is closer to the center side in the direction LD perpendicular to the expansion and contraction direction within a range in which the continuity in the direction perpendicular to the contraction direction can be maintained.

The constituent members of the 1 st sheet 20A and the 2 nd sheet 20B are not particularly limited as long as they are sheet-shaped, but from the viewpoint of breathability and flexibility, nonwoven fabrics are preferably used. The kind of the raw material fiber of the nonwoven fabric is not particularly limited. Examples thereof include olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cuprammonium fibers, natural fibers such as cotton, and the like, and mixed fibers and composite fibers using two or more of these fibers. Further, the nonwoven fabric may be produced by any process.

Examples of the processing method include known methods such as a spunlace method, a spunbond method, a hot-rolling method, a melt-blowing method, a needle-punching method, a hot-air method, and a point-bonding method. When a nonwoven fabric is used, the weight per unit area is preferably about 10 to 25g/m². In addition, a part or all of the 1 st sheet layer 20A and the 2 nd sheet layer 20B may be a pair of layers formed by folding one sheet of material and facing each other. For example, as shown in the figure, in the waist end portion 23, the component located on the outer side may be the 2 nd sheet 20B, the folded portion 20C folded back toward the inner surface side at the waist opening edge may be the 1 st sheet 20A, and the elastic film 30 may be interposed therebetween, and in the portion other than the waist end portion 23, the component located on the inner side may be the 1 st sheet 20A, the component located on the outer side may be the 2 nd sheet 20B, and the elastic film 30 may be interposed therebetween. Of course, the component of the 1 st sheet 20A and the component of the 2 nd sheet 20B may be provided separately throughout the front-rear direction LD, and the elastic film 30 may be interposed between the component of the 1 st sheet 20A and the component of the 2 nd sheet 20B without folding back the components.

The elastic film 30 is not particularly limited, and a film having a plurality of holes or slits formed therein may be used for ventilation, in addition to a non-porous film, as long as it is a thermoplastic resin film having elasticity itself. Particularly preferred are elastic films 30 as follows: the tensile strength in the width direction WD (the stretching direction ED, the MD direction) is 8-25N/35 mm, the tensile strength in the front-back direction LD (the direction LD perpendicular to the stretching direction, the CD direction) is 5-20N/35 mm, the tensile elongation in the width direction WD is 450-1050%, and the tensile elongation in the front-back direction LD is 450-1400%. The thickness of the elastic film 30 is not particularly limited, but is preferably about 20 to 40 μm.

(expansion region)

The region of the exterior body 20 having the elastic sheet stretchable structure 20X has a stretchable region capable of stretching in the width direction WD. In the stretchable region 80, there is a portion (e.g., a region indicated by reference numeral 32 in fig. 12) where the elastic film 30 is linearly continuous in the width direction WD, and it is stretchable in the width direction WD while being contracted in the width direction WD by the contraction force of the elastic film 30. More specifically, in a state where the elastic film 30 is stretched in the width direction WD, the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined to each other at intervals in the width direction WD and in the front-back direction LD perpendicular to the width direction (direction LD perpendicular to the stretching direction) via the joining holes 31 of the elastic film 30 to form a plurality of sheet joining portions 40, thereby forming the elastic sheet stretching structure 20X, and the joining holes 31 are arranged in the stretching region 80 so as to have portions 32 where the elastic film 30 is linearly continuous in the width direction WD, thereby imparting such stretchability.

In the stretch region, the 1 st sheet layer 20A and the 2 nd sheet layer 20B between the sheet-joined portions 40 swell in a direction away from each other in the natural length state to form contracted wrinkles 26 extending in the front-rear direction LD, and even in a worn state where the sheets are extended to some extent in the width direction WD, the contracted wrinkles 26 are spread out but remain.

The elastic limit elongation of the stretchable region 80 in the width direction WD is desirably set to 200% or more (preferably 265 to 295%). The ultimate elastic extension percentage of the stretchable region 80 is almost determined by the elongation percentage of the elastic film 30 at the time of production, but is reduced due to the resistance to the contraction in the width direction WD. The reason for this is mainly the proportion of the length L of the sheet joint portion 40 per unit length in the width direction WD, and the larger this proportion is, the more the elastic limit elongation rate decreases. In a normal case, the length L of the sheet joint 40 is related to the area ratio of the sheet joint 40, and therefore, the elastic limit elongation of the stretchable zone 80 can be adjusted by the area ratio of the sheet joint 40.

The area ratio of the sheet joint portions 40 in the stretchable zone 80 and the area of each sheet joint portion 40 may be determined as appropriate, but in a normal case, it is preferably set within the following range.

Area of sheet joining portion 40: 0.14 to 3.5mm²(particularly preferably 0.14 to 1.0 mm)²)

Area ratio of the sheet joining portion 40: 1.8 to 19.1% (particularly preferably 1.8 to 10.6%)

Since the proof stress and the proof stress of the stretchable region 80 can be adjusted by the area of the sheet joint portion 40 in this way, as shown in fig. 7, a plurality of regions having different area ratios of the sheet joint portion 40 can be provided in the stretchable region 80, and the fit can be changed depending on the region. In the form shown in fig. 7, in the region 81 extending diagonally along the root of the leg and the edge region 82 of the leg opening in the front body portion F, the sheet joint portion 40 has a higher area ratio than the other regions, and therefore, the elongation stress is weak, and the region is flexibly stretchable. In the opposed-to-enteron region 83 and the leg-opening edge region 82 in the posterior body section B, the sheet joint 40 also has a higher area ratio than other regions, and therefore, the extension stress is weak, and the region is flexibly stretchable.

(non-expansion region)

In the region of the outer package 20 having the elastic sheet stretchable structure 20X, as shown in fig. 7, a non-stretchable region 70 may be provided at least on one side in the width direction of the stretchable region 80. The configuration of the telescopic regions 80 and the non-telescopic regions 70 may be determined as appropriate. In the case of the outer package 20 of a pants-type disposable diaper as in the present embodiment, since the portion overlapping the absorbent body 13 is a region where expansion and contraction are not necessary, it is preferable to use a part or the whole of the portion overlapping the absorbent body 13 (desirably, the whole including the inner and outer fastening regions 10B) as the non-expansion region 70 as shown in the drawing. Of course, the non-stretchable region 70 may be provided from the region overlapping with the absorbent body 13 to the region not overlapping with the absorbent body 13 in the width direction WD or the front-back direction LD, or the non-stretchable region 70 may be provided only in the region not overlapping with the absorbent body 13.

The non-stretching region 70 is set to be a region: although the elastic film 30 is continuous in the width direction WD, it does not have a portion that is linearly continuous in the width direction WD due to the presence of the engagement holes 31. Therefore, even if the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined via the joining holes 31 of the elastic film 30 at intervals in the width direction WD and in the front-rear direction LD perpendicular to the width direction WD to form the plurality of sheet joining portions 40 in a state where the elastic film 30 is stretched in the width direction WD, thereby forming the entire elastic sheet stretchable structure 20X including both the stretchable region 80 and the non-stretchable region 70, in the non-stretchable region 70, since the elastic film 30 is not linearly continuous in the width direction WD, the contractive force of the elastic film 30 hardly acts on the 1 st sheet layer 20A and the 2 nd sheet layer 20B, the stretchability is almost lost, and the ultimate elongation approaches 100%.

In such a non-stretch region 70, the 1 st sheet layer 20A and the 2 nd sheet layer 20B are joined together at a plurality of sheet joining portions 40 arranged at intervals, and the sheet joining portions 40 are discontinuous, so that a decrease in flexibility is prevented.

The arrangement pattern of the engaging holes 31 in the elastic film 30 in the non-stretch region 70 may be determined as appropriate.

The area ratio of the sheet joint portions 40 in the non-stretchable region and the area ratio of each sheet joint portion 40 may be appropriately determined, but in a normal case, if the area ratio is set within the range described below, the area ratio of each sheet joint portion 40 is small and the area ratio of the sheet joint portion 40 is low, and thus the non-stretchable region 70 is not hardened, which is preferable.

Area of sheet joining portion 40: 0.10 to 0.75mm²(particularly preferably 0.10 to 0.35 mm)²)

Area ratio of the sheet joining portion 40: 4 to 13% (particularly preferably 5 to 10%)

In the above examples, an elastic film is used as the elastic sheet. However, elastic nonwoven fabrics may also be used. Alternatively, an elastic nonwoven fabric may be provided on one side or both sides of the elastic film so as to be interposed between the 1 st sheet layer 20A and the 2 nd sheet layer 20B.

< description of words in the specification >)

Unless otherwise specified in the specification, the following terms in the specification have the following meanings.

"front body portion" and "back body portion" refer to portions located on the front side and the back side, respectively, with the center in the front-back direction of the pants-type disposable diaper as a boundary. The crotch portion refers to a front-rear direction range including a front-rear direction center of the pants-type disposable diaper, and when the absorber has a constricted portion, refers to a front-rear direction range of a portion having the constricted portion.

"ultimate elastic elongation" means the elongation at the elastic limit in the stretching direction ED (in other words, in a state where the 1 st sheet and the 2 nd sheet are completely unfolded), and is an amount representing the length at the elastic limit in percentage assuming that the natural length is 100%.

The "area ratio" is a ratio of the target portion per unit area, and is expressed as a percentage by calculating the total area of the target portion (for example, the sheet joint portion 40, the opening of the joint hole 31, and the ventilation hole) in the target region (for example, the stretchable region 80 and the non-stretchable region 70) by dividing the area of the target region, and particularly, the "area ratio" in the region having the stretchable structure is an area ratio in a state of being stretched to the elastic limit in the stretching direction ED. In the aspect in which a plurality of target portions are provided at intervals, it is desirable that: the target area is set to a size including 10 or more target portions, and the area ratio is obtained.

"elongation" means a value when the natural length is 100%.

"weight per unit area" is measured as follows. The sample or test piece is dried and placed in a laboratory or apparatus in a standard state (the temperature in the test site is 23. + -. 1 ℃ C., and the relative humidity is 50. + -. 2%) so as to be in a constant state. The preliminary baking means that the sample or the test piece is made constant in an environment at a temperature of 100 ℃. In addition, the fibers having a official moisture regain of 0.0% may not be subjected to preliminary drying. Using a template (100 mm. times.100 mm) for sample selection, a sample having a size of 100 mm. times.100 mm was cut out from the test piece in a constant state. The weight of the sample was measured, and the weight per square meter was calculated as a weight per unit area by 100 times.

The "thickness" of the absorber was measured by leveling the sample and a thickness gauge (PEACOCK, Diagram thickness gauge, large type, model J-B (measurement range 0 to 35mm) or model K-4 (measurement range 0 to 50mm)) manufactured by Kawasaki corporation.

"thickness" other than the above is measured under a load of 0.098N/cm using an automatic thickness measuring instrument (KES-G5 Portable compression measurement program)²The pressure area is 2cm²Is automatically measured under the conditions of (1).

"tensile strength" and "tensile elongation (elongation at break)" mean that, in addition to the test piece being set in a rectangular shape having a width of 35mm × a length of 80mm, the tensile strength and the elongation at break are measured in accordance with JIS K7127: 1999 "test method of Plastic-tensile Properties-", a value measured with an initial inspection interval (distance between graduations) of 50mm and a tensile speed of 300 mm/min. As the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU corporation may be used.

"elongation stress" means the stress according to JIS K7127: 1999 "test method for Plastic-tensile Properties-", the degree of elongation can be determined appropriately according to the test subjects by the tensile test with the initial inspection interval (distance between graduations) set to 50mm and the tensile speed set to 300mm/min, the tensile stress (N/35mm) measured when the elongation is performed in the elastic region. The test piece is preferably set in a rectangular shape having a width of 35mm and a length of 80mm or more, but when a test piece having a width of 35mm cannot be cut, a test piece is prepared with a width that can be cut, and the measurement value is converted into a value in the case of a width of 35 mm. Even when the target region is small and a sufficient test piece cannot be obtained, if the magnitude of the elongation stress is compared, at least the comparison can be performed by appropriately using test pieces having the same size even if the test pieces are small. As the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU corporation may be used.

"expanded state" refers to a state of flat expansion without contraction and relaxation.

The dimensions of the respective portions are not particularly described, and are dimensions in the expanded state, not the natural length state.

The test or measurement is carried out in a laboratory or apparatus in a standard state (in a test site, the temperature is 23 ± 1 ℃, and the relative humidity is 50 ± 2%) without describing the environmental conditions in the test or measurement.

Industrial applicability

As long as the present invention is an article having a stretchable region to which the elastic sheet stretchable structure can be applied, the present invention can be used for all disposable wearing articles such as various disposable diapers of a tape type, a pad type, and the like, sanitary napkins, disposable wearing articles for swimming or paddling, and the like, in addition to the pants type disposable diapers as in the above examples.

Description of the reference symbols

10: an interior body; 10B: an inner and outer fixed area; 11: a topsheet; 12: a liquid-impermeable sheet; 13: an absorbent body; 13N: a narrowed portion; 14: packaging the sheet; 17: an absorbent-free side portion; 20: an exterior body; 20A: a1 st slice layer; 20B: a2 nd slice layer; 20C: a fold-back section; 20X: the elastic piece is of a telescopic structure; 21: a side seal part; 23: a waist end portion; 24: a waist elastic member; 25F, 25F: shrinking the wrinkles; 26: shrinking the wrinkles; 29: leg girth lines; 30: an elastic film; 31: an engagement hole; 33: air holes are formed; 40: a sheet joining portion (1 st joining portion); 41: a2 nd engaging part; 42: a3 rd engaging part; 43: the 4 th joint part; 70: a non-stretch region; 80: a telescoping region; 90: a three-dimensional gather portion; 93: a lodging part; 94: a free portion; 95: a gusset; 96: a gather portion elastic member; b: a posterior portion; ED: the expansion direction (width direction); f: a precursor portion; l: an intermediate portion; LD: a vertical direction (front-rear direction); t: a waist portion.