Stretchable member and disposable wearing article provided with stretchable member

Abstract

The invention provides a stretchable member and a disposable wearable article having the stretchable member. The stretchable member has an elastic sheet stretchable structure (20X) in which an elastic sheet (30) is interposed between a first sheet layer (20A) comprising a non-woven fabric and a second sheet layer (20B) comprising a non-woven fabric, and the first sheet layer (20A) and the second sheet layer (20B) are welded together through joining holes (31) penetrating the elastic sheet (30) at a plurality of sheet joining parts (40) arranged at intervals. The region having the elastic sheet stretchable structure (20X) has sheet bonding sections (40) having different shapes, and for all of the sheet bonding sections (40) in the region having the elastic sheet stretchable structure (20X), the bonding reference diameter () is 0.2 mm or more, the maximum value of the bonding reference diameter (40) is 1-3 times the minimum value, and the circumferential length is 1-15 times the circumferential length of a circle having the bonding reference diameter as the diameter.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201880045667.X (PCT / JP2018 / 035311), filed on September 25, 2018, entitled "Telescopic component, disposable wearable article having the telescopic component and method of manufacturing the telescopic component". Technical Field

[0002] The present invention relates to a telescopic component and a disposable wearable article having the telescopic component, wherein the telescopic component has a telescopic structure formed by elastic sheets such as an elastic membrane sandwiched between a first layer and a second layer. Background Technology

[0003] In disposable clothing items such as disposable diapers, to improve the fit to the body, elasticity is typically provided in appropriate areas such as the leg openings or waistband. Conventionally, a common method for providing elasticity is to install elongated elastic components such as rubber threads in a lengthwise extended state. However, when a certain degree of elasticity across a certain width is desired, rubber threads are fixed in a side-by-side arrangement spaced apart across the width. Furthermore, as a further improvement in fit, a method has been proposed where elastic sheets are installed in a lengthwise extended state along the direction of elasticity (see, for example, Patent Documents 1 and 2).

[0004] The telescopic member comprising elastic sheets is formed as follows: with an elastic membrane stacked between a first layer and a second layer and the elastic membrane elongated in the telescopic direction, the first layer and the second layer are fused together through joint holes formed in the elastic membrane at a plurality of point-like sheet joints spaced apart in both the telescopic direction and a direction perpendicular to the telescopic direction. Furthermore, regarding this telescopic member, in its natural length state, as the elastic sheets contract between the sheet joints, the interval between the sheet joints narrows, and folds extending in a direction intersecting the telescopic direction are formed between the sheet joints on the first layer and the second layer. Conversely, upon elongation, as the elastic sheets elongate between the sheet joints, the interval between the sheet joints and the folds on the first and second layers expand, allowing it to elastically elongate to the fully expanded state of the first and second layers. The elastic sheet's stretchable area has the following advantages: it is excellent in terms of fit, and because there is no bonding between the first and second layers and the elastic sheet, and the bonding between the first and second layers is minimal, it is very soft. In addition, the bonding holes of the elastic sheet also help to improve breathability.

[0005] On the other hand, regarding the telescopic component containing the elastic sheet, since the telescopicity and appearance vary depending on the shape of the sheet joint, it is desirable to provide multiple sheet joints with different shapes depending on the part of the disposable garment.

[0006] However, when setting multiple sheet joints with different shapes, the following situation exists: at some sheet joints, the first sheet layer and the second sheet layer are not fused together, or they are in a state where they are fused together but will peel off under the action of a weak force (poor fusion).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2016-189932

[0010] Patent Document 2: Japanese Patent Application Publication No. 2015-204982 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] Therefore, the main objective of this invention is to make it difficult to cause poor welding in cases where there are sheet joints with different shapes.

[0013] Methods for solving problems

[0014] The following describes a telescopic component that solves the above-mentioned problems, a disposable wearable item having the telescopic component, and a method for manufacturing the telescopic component.

[0015] <Method 1>

[0016] A telescopic component, characterized in that the telescopic component has an elastic sheet telescopic structure as follows: an elastic sheet is located between a first layer made of nonwoven fabric and a second layer made of nonwoven fabric, the first layer and the second layer are fused together through joint holes in the elastic sheet at a plurality of spaced-apart joints, the region having the elastic sheet telescopic structure has a telescopic region, the telescopic region shrinks in the telescopic direction by means of the contraction of the elastic sheet, and is able to stretch in the telescopic direction, the region having the elastic sheet telescopic structure has joints of different shapes, for all the joints in the region having the elastic sheet telescopic structure, the joint reference diameter is 0.2 mm or more, the maximum value of the joint reference diameter is 1 to 3 times the minimum value, and the circumference is 1 to 15 times the circumference of a circle with the joint reference diameter as its diameter.

[0017] (Effects)

[0018] The inventors investigated the aforementioned welding defects and found that welding defects in the presence of sheet joints with different shapes can be improved by increasing the linear pressure during the formation of the sheet joint (in the case of ultrasonic sealing, increasing the loading pressure). However, this improvement has its limits and can lead to premature wear or damage to equipment such as support rollers, making it undesirable. Therefore, the causes of welding defects were further investigated, and it was found that even in the presence of sheet joints with different shapes, welding defects can be less likely to occur by setting the joining reference diameter and circumference within a specific range as described above. Here, the joining reference diameter refers to the diameter of the largest inscribed circle that is inscribed within the outer shape of the sheet joint.

[0019] The reason why setting the joining reference diameter and circumference within a specific range, as described above, can reduce the likelihood of poor welding is as follows: In welding, heat needs to be distributed relatively evenly and sufficiently from the center of the heated portion in a radial direction to melt the nonwoven fabric. For this purpose, it is preferable that the sheet joint has a shape that can contain a sufficiently large circle, i.e., a joining reference diameter of a certain degree or higher. According to the inventors' research, the lower limit of this joining reference diameter is 0.2 mm. Furthermore, sheet joints with excessively long or overly complex shapes are prone to partial welding defects. From this viewpoint, it is preferable that the circumference of the sheet joint is within the aforementioned range. Additionally, if the difference in joining reference diameters between the sheet joints is too large, poor welding is likely to occur when the linear pressure during the formation of the sheet joint matches the sheet joint with a larger joining reference diameter. Furthermore, increasing the linear pressure during the formation of the sheet joint based on the smaller joining reference diameter may lead to premature wear or damage to equipment such as support rollers. In this regard, when the joint reference diameter is set to a specific range as described above, it is possible to achieve a weld that is less likely to cause poor weld under appropriate pressure.

[0020] <Method 2>

[0021] According to the telescopic component of the first method, the first layer and the second layer have a linear density of 0.7 dtex to 6 dtex and a unit area weight of 10 g / m². 2 ~25g / m 2 The nonwoven fabric having a joint reference diameter of 0.2 mm to 0.8 mm in all the joint portions of the sheet in the region having the elastic sheet stretching structure.

[0022] (Effects)

[0023] To suppress poor welding while preventing premature wear and breakage of the equipment, the above-mentioned range of nonwoven fabric and bonding reference diameter is particularly preferred.

[0024] <Third Method>

[0025] According to the first or second embodiment of the telescopic component, the region having the elastic sheet telescopic structure has a telescopic region and a non-telescopic region, the non-telescopic region being disposed on at least one side of the telescopic region in the telescopic direction, the area ratio of the sheet joint in the telescopic region being 0.5 to 1 times the area ratio of the sheet joint in the non-telescopic region, and the boundary between the telescopic region and the non-telescopic region having a shape that continuously shifts only to one side of the telescopic direction as it moves from one end toward the other.

[0026] (Effects)

[0027] The stretching characteristics can be changed by varying the area ratio of the joint. However, if the area ratio of the joint changes drastically—that is, if the boundary between the stretching and non-stretching regions changes along a direction perpendicular to the stretching direction from one end to the other—then during welding, the linear pressure changes drastically at the boundary between the stretching and non-stretching regions. Such a drastic change in linear pressure may lead to premature wear or damage to equipment such as support rollers. In contrast, in this method, there is no drastic change in linear pressure during welding; therefore, there is less concern about premature wear or damage to equipment such as support rollers.

[0028] <The Fourth Method>

[0029] A disposable garment, characterized in that it is a shorts-type disposable garment, comprising: an integral outer body extending from the front to the back, or outer bodies respectively disposed in the front and back portions; an inner body installed in the middle of the width direction of the outer body and extending to the front and back sides of the crotch portion; side closures formed by joining the side portions of the outer body in the front portion and the side portions of the outer body in the back portion together; and a waist opening and a pair of left and right leg openings, wherein the outer body in the front portion and the outer body in the back portion have a waist portion extending in the front-to-back direction corresponding to the side closures, and at least one of the outer bodies in the front and back portions has an outer body positioned closer to the center in the front-to-back direction than the waist portion. The middle part of the side has an edge region along the leg opening. The outer body having the middle part is a telescopic member having a first-type elastic sheet telescopic structure that extends from the middle part to the waist part in the front-back direction and extends between the side seals in the width direction. The telescopic direction of the telescopic region of the elastic sheet telescopic structure is the width direction. The shape of the sheet joint in the edge region along the leg opening is different from the shape of the sheet joint in other regions. For all the sheet joints in the edge region along the leg opening and other regions, the joint reference diameter is 0.2 mm or more, the maximum value of the joint reference diameter is 1 to 3 times the minimum value, and the circumference is 1 to 15 times the circumference length of a circle with the joint reference diameter as its diameter.

[0030] (Effects)

[0031] The aforementioned elastic component, as described in this embodiment, is suitable for the outer body of disposable shorts-type garments. Particularly preferred is the provision of an elastic sheet elastic structure extending from the center section to the waist section in the front-to-back direction and throughout the side panels in the width direction, such that the elasticity along the edge of the leg opening differs from that in other areas, thereby improving the fit of the leg opening and other areas. In this case, the shape of the sheet joint in the area along the edge of the leg opening differs from that in other areas, potentially leading to poor welding. However, by setting the joint reference diameter and circumference within a specific range as described above, a weld that is less prone to poor welding can be achieved under appropriate pressure, as explained in the first embodiment.

[0032] <The Fifth Method>

[0033] According to the fourth method of disposable clothing, the outer body having the elastic sheet stretch structure has a non-stretchable region in the middle of the width direction, and the width direction range corresponding to the non-stretchable region and the side seal is the stretchable region, the area ratio of the sheet joint in the stretchable region is 0.5 to 1 times that of the area ratio of the sheet joint in the non-stretchable region, and the boundary between the stretchable region and the non-stretchable region has a shape that continuously shifts towards the side seal only as it moves from the end on the waist opening side toward the center of the disposable clothing in the front-rear direction.

[0034] (Effects)

[0035] In shorts-type disposable garments, the non-stretchable area is typically located at the position described in this method. Therefore, in this case, it is desirable to offset the boundary between the stretchable and non-stretchable areas in the vertical direction, similar to the third method. However, in this case, the boundary between the stretchable and non-stretchable areas extends in the front-back direction of the shorts-type disposable garment; therefore, from the viewpoint of ensuring a good fit, a shorter stretchable area on the waist opening side is not preferred. Therefore, it is preferable, as in this method, that the boundary between the stretchable and non-stretchable areas continuously shifts towards the side closure side only, moving from the end on the waist opening side towards the center of the disposable garment in the front-back direction.

[0036] <Method 6>

[0037] A method for manufacturing a telescopic component, characterized in that the method comprises: a feeding step, wherein an elastic sheet is positioned between a first layer and a second layer in an elongated state along the MD direction; and a joining step, wherein the first layer, the second layer, and the elongated elastic sheet positioned between the first layer and the second layer pass between a support roller and an ultrasonic welding head facing the outer peripheral surface of the support roller, wherein the support roller has a plurality of protrusions arranged at intervals according to a predetermined pattern on its outer peripheral surface, and only the portions of the first layer and the second layer sandwiched between the plurality of protrusions and the ultrasonic welding head are fused together to form a sheet joint, and sheet joints with different joining reference diameters are formed by means of an ultrasonic welding head, and for all the sheet joints formed by means of an ultrasonic welding head, the joining reference diameter is 0.2 mm or more, the maximum value of the joining reference diameter is 1 to 3 times the minimum value, and the circumference is 1 to 15 times the circumference of a circle with the joining reference diameter as its diameter.

[0038] (Effects)

[0039] When the joint of the sheet is formed by ultrasonic sealing, it can achieve the same effect as the first method.

[0040] <The 7th Method>

[0041] A method for manufacturing a telescopic component, characterized in that the method comprises: a feeding step, wherein an elastic sheet is positioned between a first layer and a second layer in an elongated state along the MD direction; and a joining step, wherein the first layer, the second layer, and the elongated elastic sheet positioned between the first layer and the second layer pass between a support roller and a counter roller facing the outer peripheral surface of the support roller, wherein the support roller has a plurality of protrusions arranged at intervals according to a predetermined pattern on its outer peripheral surface, and the method utilizes a heated... The support roller and the opposing roller weld together only the portions of the first and second layers sandwiched between the plurality of protrusions and the opposing roller to form a sheet joint. The support roller and the opposing roller, as a pair, form sheet joints with different joining reference diameters. For all the sheet joints formed by the support roller and the opposing roller, the joining reference diameter is 0.2 mm or more, the maximum value of the joining reference diameter is 1 to 3 times the minimum value, and the circumference is 1 to 15 times the circumference of a circle with the joining reference diameter as its diameter.

[0042] (Effects)

[0043] When the sheet joint is formed by heat sealing, it can achieve the same effect as the first method.

[0044] The effects of the invention

[0045] According to the present invention, it has the following advantages: it is difficult to cause poor welding in the case of sheet joints with different shapes. Attached Figure Description

[0046] Figure 1 This is a top view (inner surface side) of a shorts-type disposable diaper in its unfolded state.

[0047] Figure 2 This is a top view (outer surface side) of a shorts-type disposable diaper in its unfolded state.

[0048] Figure 3 This is a top view showing only the key parts of a shorts-type disposable diaper in its unfolded state.

[0049] Figure 4 (a) is along Figure 1 A cross-sectional view of the CC line in the middle. Figure 4 (b) is along Figure 1 A cross-sectional view of the EE line.

[0050] Figure 5 It is along Figure 1 A cross-sectional view along line AA in the diagram.

[0051] Figure 6 It is along Figure 1 A cross-sectional view of the BB line.

[0052] Figure 7 (a) is a top view of an important part of the stretchable area. Figure 7 (b) is along Figure 7 (a) is a cross-sectional view of the DD line. Figure 7 (c) is a cross-sectional view of the garment in its worn state. Figure 7 (d) is a cross-sectional view at its natural length.

[0053] Figure 8 It is a cross-sectional view that schematically shows the cross-section of an important part of the outer casing that has been stretched to a certain extent.

[0054] Figure 9 (a) is a top view of an important part of the stretchable area. Figure 9 (b) is along Figure 9 A sectional view of line DD in (a). Figure 9 (c) is a cross-sectional view of the garment in its worn state. Figure 9 (d) is a cross-sectional view at its natural length.

[0055] Figure 10 It is a top view showing various arrangements of the joints.

[0056] Figure 11 This is a top view of the expanded area.

[0057] Figure 12 This is a top view showing an enlarged portion of the expandable area in its unfolded state.

[0058] Figure 13 It is a top view showing an enlarged portion of the stretchable area in its natural length state.

[0059] Figure 14 (a) is along Figure 12 A cross-sectional view of the DD line in the middle. Figure 14 (b) is a cross-sectional view at its natural length.

[0060] Figure 15 This is a top view of the expanded area.

[0061] Figure 16 This is a top view showing an enlarged portion of the expandable area in its unfolded state.

[0062] Figure 17 It is a top view showing an enlarged portion of the stretchable area in its natural length state.

[0063] Figure 18 This is a front view showing only the key parts of a shorts-type disposable diaper.

[0064] Figure 19 This is a front view showing only the key parts of a shorts-type disposable diaper.

[0065] Figure 20 This is a front view showing only the key parts of a shorts-type disposable diaper.

[0066] Figure 21 This is a schematic diagram of an ultrasonic sealing device.

[0067] Figure 22 It is Figure 2 The top view shown is an enlarged view of the Q section.

[0068] Figure 23 It is Figure 2 The top view shown is an enlarged view of the Q section.

[0069] Figure 24 It is a top view showing various shapes of the joint. Detailed Implementation

[0070] The following describes in detail the elastic component, the disposable garment, and the manufacturing method of the elastic component, based on the example of the shorts-type disposable diaper shown in the attached drawings. Furthermore, the dotted areas in the cross-sectional view represent joining methods such as hot-melt adhesives.

[0071] Figures 1-6 A shorts-type disposable diaper is shown. The designation LD (longitudinal) indicates the front-to-back direction, and WD indicates the width direction. This shorts-type disposable diaper (hereinafter simply referred to as a diaper) has: an outer body 20, which constitutes a front portion F and a back portion B; and an inner body 10, which is fixed to the inner surface of the outer body 20 to form a single unit. The inner body 10 is formed by sandwiching an absorbent body 13 between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. During manufacturing, after the back side of the inner body 10 is bonded to the inner surface (upper surface) of the outer body 20 by means of a hot-melt adhesive, the inner body 10 and the outer body 20 are folded at the boundary between the front portion F and the back portion B, i.e., at the center of the front-to-back direction LD (longitudinal), so that their two sides are joined together by a hot-melt weld or a hot-melt adhesive to form a side seal 21, thereby becoming a shorts-type disposable diaper with a waist opening and a pair of leg openings on the left and right sides.

[0072] (Example of internal structure)

[0073] like Figures 4-6As shown, the inner body 10 has an absorbent 13 positioned between the top sheet 11 and a liquid-impermeable sheet 12 made of polyethylene or the like, for absorbing and retaining excreted liquid that has permeated through the top sheet 11. The planar shape of the inner body 10 is not particularly limited, but is generally as follows... Figure 1 It is set to be roughly rectangular as shown.

[0074] The top sheet 11, which covers the front side (skin side) of the absorbent 13, is preferably made of a nonwoven fabric with or without holes, or a porous plastic sheet. In addition to synthetic fibers such as polyethylene or polypropylene, polyester, and polyamide, the fabric fibers constituting the nonwoven fabric can also be recycled fibers such as rayon or cuprammonium rayon, and natural fibers such as cotton. This allows for the use of nonwoven fabrics obtained through appropriate processing methods such as hydroentangling, spunbonding, thermal bonding, meltblowing, and needle punching.

[0075] As the liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene can be used. In particular, from the viewpoint of preventing stuffiness, a moisture-permeable sheet can be used appropriately. For example, a microporous sheet obtained by means of melting and mixing an inorganic filler material in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching it in a uniaxial or biaxial direction.

[0076] As the absorbent 13, known materials can be used, such as aggregates of pulp fibers, cellulose acetate filaments, or nonwoven fabrics, with highly absorbent polymers mixed or fixed as needed. Considering shape and polymer retention, the absorbent 13 can be packaged using packaging sheets 14 with liquid permeability and liquid retention properties, such as crepe paper, as needed.

[0077] The absorbent body 13 is shaped like an hourglass, with a narrower portion 13N in the crotch area that is narrower than the front and rear sides. The size of the narrower portion 13N can be appropriately determined; the front-to-back length of the narrower portion 13N can be set to approximately 20-50% of the total length of the diaper, and the width of its narrowest part can be set to approximately 40-60% of the total width of the absorbent body 13. When the narrower portion 13N is provided, if the planar shape of the inner body 10 is formed to be approximately rectangular, a non-absorbent side 17 without the absorbent body 13 is formed on the inner body 10 corresponding to the narrower portion 13N of the absorbent body 13.

[0078] The impermeable sheet 12, together with the top sheet 11, is folded back towards the back side on both sides of the absorbent body 13 in the width direction. It is desirable to use an opaque sheet 12 to prevent the brown color of feces or urine from showing through. As an opaque sheet, it is preferable to use a sheet made by adding pigments or fillers such as calcium carbonate, titanium dioxide, zinc oxide, silica, clay, talc, and barium sulfate to a plastic and then thinning it.

[0079] Three-dimensional pleats 90, suitable for leg circumference, are formed on both sides of the inner body 10. For example... Figure 5 and Figure 6 As shown, the three-dimensional pleated portion 90 includes: a fixing portion 91, which is fixed to the side of the back of the inner body 10; a main body portion 92, which extends from the fixing portion 91, passing through the side of the inner body 10, and above the side of the front of the inner body 10; a folded portion 93, which is formed by fixing the front and rear ends of the main body portion 92 to the side of the front of the inner body 10 (top piece 11 in the example) in a folded state using a hot melt adhesive 95b or the like; and a free portion 94, which is formed by not fixing the folded portions 93 together. Each of the above portions is formed by a pleated piece 95, which is formed by folding back a sheet of non-woven fabric or the like to form a double-layer sheet. The pleated piece 95 is installed throughout the entire front-rear direction of the inner body 10, the folded portion 93 is positioned in front of and behind the non-absorbent side 17, and the free portion 94 extends to the front and rear sides of the non-absorbent side 17. Furthermore, between the double-layered pleated pieces 95, a pleated elastic member 96 is provided at the end of the free portion. The pleated elastic member 96 is used to ensure that, in the product state... Figure 5 As shown, the free part 94 is raised by means of elastic contraction.

[0080] The fixing structure of the elastic component 96 of the pleat section and the pleat piece 95 is not particularly limited; for example, it can be as follows: Figure 5 and Figure 6 The example shown employs the following structure: outside the collapsed portion 93, the pleated elastic member 96 is bonded and fixed to the pleated piece 95 by means of a hot melt adhesive at the location of the pleated elastic member 96, and the opposing surfaces of the pleated pieces 95 are joined together. However, in the collapsed portion 93, there is no hot melt adhesive at the location of the pleated elastic member 96. Therefore, the pleated elastic member 96 and the pleated piece 95 are not bonded together, and the opposing surfaces of the pleated pieces 95 are not joined together at the location where the pleated elastic member 96 is located.

[0081] The elastic component 96 for the pleats can be made of commonly used materials such as styrene-based rubber, olefin-based rubber, polyurethane-based rubber, ester-based rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene polymer, silicone, and polyester. Furthermore, to minimize visibility from the outside, it is suitable to have a thickness of 925 dtex or less, a tension of 150–350%, and a spacing of 7.0 mm or less. In addition to the elongated shape shown in the illustrated example, the elastic component 96 for the pleats can also be a strip with a certain width.

[0082] The fabric fibers constituting the aforementioned pleated piece 95 are the same as those of the top piece 11. In addition to synthetic fibers such as polyethylene or polypropylene, polyester, and polyamide, regenerated fibers such as rayon or cuprammonium filament, and natural fibers such as cotton can also be used. This allows for the use of nonwoven fabrics obtained through appropriate processing methods such as spunbonding, thermal bonding, meltblowing, and needle punching. In particular, to prevent stuffiness, nonwoven fabrics with reduced basis weight and excellent breathability are suitable. Furthermore, regarding the pleated piece 95, to prevent urine from seeping through, and to prevent rashes and improve skin feel (dryness), it is desirable to use nonwoven fabrics coated with hydrophobic agents such as silicone-based, paraffin-based, or alkyl chromic chloride-based hydrophobic agents.

[0083] like Figures 3-6 As shown, the back surface of the inner body 10 is bonded to the inner surface of the outer body 20 in the inner and outer fixing regions 10B (diagonal lines) by hot melt adhesive or the like. Regarding the inner and outer fixing regions 10B, it can be appropriately determined that they are set to be almost the entire width direction WD of the inner body 10, but it is preferable that the two ends in the width direction are not fixed to the outer body 20.

[0084] (Example of the structure of the outer casing)

[0085] The outer garment 20 has at least a waist portion T of the front body portion F and a waist portion T of the rear body portion B. In the illustrated example, it also has a middle portion L that forms the front-to-back direction range between the waist portion T of the front body portion F and the waist portion T of the rear body portion B. Regarding the outer garment 20, as in the illustrated example, the side edge of the outer garment 20 may be positioned at the crotch area closer to the center of the width direction than the side edge of the inner garment 10, or the side edge of the outer garment 20 may be positioned at the crotch area further outward in the width direction than the side edge of the inner garment 10.

[0086] Furthermore, in the illustrated example of the outer casing 20, except for the middle part L in the front-to-back direction, as shown... Figure 2 and Figures 4-6 As shown, an elastic sheet 30 is sandwiched between the first layer 20A and the second layer 20B, and, as Figure 7 and Figure 9 As shown, the elastic sheet stretch structure 20X is formed as follows: a first sheet layer 20A and a second sheet layer 20B are joined together at a plurality of sheet joints 40 arranged at intervals, passing through a joint hole 31 in the elastic sheet 30. Furthermore, the area having this elastic sheet stretch structure has a stretchable region that can contract in the width direction by means of the contraction of the elastic sheet and can extend in the width direction (i.e., the stretch direction ED is the width direction WD of the diaper).

[0087] The planar shape of the outer garment 20 is formed by concave leg openings on both sides of the width direction of the middle part L, and is formed in an hourglass shape as a whole. The outer garment 20 can be configured such that the outer garment 20 is formed on the front part F and the back part B respectively, and the two are separated at the crotch part along the front-back direction LD of the diaper.

[0088] Figure 1 and Figure 2 The illustrated configuration is such that, instead of an elastic sheet telescopic structure 20X at the waist end 23, a conventional telescopic structure based on a slender waist elastic member 24 is used. However, it could also be a configuration where the elastic sheet telescopic structure 20X extends to the waist end 23. The waist elastic member 24 is a plurality of slender elastic members, such as rubber threads, spaced apart in the front-to-back direction LD, providing elasticity by fastening the waistline of the body. Regarding the waist elastic members 24, they are not arranged in a tightly packed bundle, but rather three or more are arranged at intervals of approximately 3 to 8 mm in the front-to-back direction to form a defined telescopic area; preferably, five or more are arranged. The elongation rate of the waist elastic member 24 when fixed can be appropriately determined, but in the case of typical adult use, it can be set to approximately 230% to 320%. Rubber threads are used for the waist elastic member 24 in the illustrated example, but other slender telescopic members, such as flat rubber, can also be used. Although not shown in the figure, it is also possible to provide an elastic sheet 30 at the waist end 23 and an elongated waist elastic member 24 at a position coinciding with the elastic sheet 30, thereby forming a telescopic structure based on the elastic members on both sides. Furthermore, in the illustrated configuration, the telescopic region of the elastic sheet telescopic structure 20X extends to the edge region 82 of the leg opening in the outer casing 20. Therefore, an elongated elastic member extending along the leg opening is not provided in the edge region 82 of the leg opening in the outer casing 20, but an elongated elastic member may be provided at a position coinciding with the elastic sheet 30 in the edge region 82, or an elongated elastic member may be provided instead of the elastic sheet 30 in the edge region 82.

[0089] Other forms, though not illustrated, may be modified as follows: the form in which the elastic sheet stretching structure 20X is not provided in the middle part L between the waist part T of the front body part F and the waist part T of the rear body part B; or, the elastic sheet stretching structure 20X is provided continuously in the front-to-back direction LD from the waist part T of the front body part F through the middle part L to the waist part T of the rear body part B; or the elastic sheet stretching structure 20X is provided only in either the front body part F or the rear body part B.

[0090] (Expandable area)

[0091] The area of ​​the outer casing 20 with the elastic sheet telescopic structure 20X has a telescopic region capable of telescopic movement in the width direction WD. In the telescopic region 80, it contracts in the width direction WD by means of the contraction force of the elastic sheet 30, and can also extend in the width direction WD. More specifically, with the elastic sheet 30 extended in the width direction WD, the first sheet layer 20A and the second sheet layer 20B are joined at intervals in the width direction WD and the front-rear direction LD (the direction perpendicular to the telescopic direction), respectively, through the joining holes 31 of the elastic sheet 30, forming a plurality of sheet joint portions 40, thereby forming the elastic sheet telescopic structure 20X. Furthermore, in the telescopic region 80, the sheet joint portions 40 are arranged such that the elastic sheet 30 remains uninterrupted in the width direction WD, and the first sheet layer 20A and the second sheet layer 20B contract by means of the contraction force of the elastic sheet 30 to form a contraction fold 25, thereby giving such telescopicity.

[0092] Within the expansion / contraction area 80, it is possible to... Figure 7 and Figure 9 As shown in the example, the elastic sheet 30 has a continuous portion 32 along the width direction WD, or it can be like... Figure 11 The examples shown and Figure 15 The example shown does not have such a part.

[0093] In the stretchable region, at its natural length, such as Figure 7 of (d), Figure 9 (d) and Figure 14 As shown in (b), the first layer 20A and the second layer 20B between the sheet joints 40 bulge in a direction separating from each other, forming a contraction fold 25 extending in the front-rear direction LD. Even in the worn state where it has been stretched to a certain extent in the width direction WD, the contraction fold 25 remains although it has been unfolded. Furthermore, if, as shown in the diagram, the first layer 20A and the second layer 20B are not joined to the elastic sheet 30 at least between the first layer 20A and the second layer 20B in the sheet joints 40, then according to the envisioned worn state... Figure 7 (c) and Figure 9(c) and the unfolded state of the first layer 20A and the second layer 20B. Figure 7 (a), (b) and Figure 9 As can be seen from (a) and (b), in these states, a gap is formed between the engagement hole 31 on the elastic sheet 30 and the sheet joint portion 40, and even if the material of the elastic sheet 30 is a non-porous membrane or sheet, air permeability can be provided through this gap. In particular, when there is a portion 32 in which the elastic sheet 30 is linearly continuous along the width direction WD, the engagement hole 31 is narrowed due to the further contraction of the elastic sheet 30 in its natural length state, thus forming a shape in which almost no gap is formed between the engagement hole 31 and the sheet joint portion 40. When there is no portion in which the elastic sheet 30 is linearly continuous along the width direction WD, a gap remains between the engagement hole 31 and the sheet joint portion 40.

[0094] Ideally, the maximum elongation of the telescopic region 80 in the width direction WD should be 190% or more (preferably 200-220%). The maximum elongation of the telescopic region 80 is almost entirely determined by the elongation of the elastic sheet 30 during manufacturing; however, it is reduced due to factors that hinder contraction in the width direction WD. This resistance is primarily due to the proportion of the length L of the sheet joint 40 per unit length in the width direction WD; the larger this proportion, the greater the reduction in the maximum elongation. Typically, the length L of the sheet joint 40 is related to the area ratio of the sheet joint 40; therefore, the maximum elongation of the telescopic region 80 can be adjusted by the area ratio of the sheet joint 40.

[0095] For the elongation stress in the expansion region 80, in such a case... Figure 7 and Figure 9 In the example shown, where the elastic sheet 30 has a continuous portion 32 along the width direction WD, it is possible to mainly pass through the continuous portion 32 along the width direction WD of the elastic sheet 30 (see reference). Figure 7 (a) and Figure 9 The adjustment is made by summing the vertical dimension 32w of (a) (which is equal to the spacing 31d of the mating hole). On the other hand, in such Figure 11 The examples shown and Figure 15 In the example shown, where there is no part where the elastic sheet 30 is continuous in a straight line along the width direction WD, the angle between the continuous direction of the unjointed strips 51 and 52 and the stretching direction ED can be adjusted. In general, it is preferable that, in the unfolded state, the acute-angled side intersection angles θ1 and θ2 between the continuous direction of the unjointed strips 51 and 52 and the stretching direction ED are greater than 0 degrees and less than 45 degrees, and are particularly preferably in the range of 10 to 30 degrees.

[0096] The area ratio of the sheet joint 40 in the telescopic region 80 and the area of ​​each sheet joint 40 can be appropriately determined, but under normal circumstances, it is preferred to set it within the following range.

[0097] Area of ​​the joint 40: 0.14–3.5 mm 2 (A preferred size is 0.14–1.0 mm) 2 )

[0098] The area ratio of the sheet joint 40 is 1.8% to 19.1% (particularly preferred is 1.8% to 10.6%).

[0099] Thus, since the maximum elongation and elongation stress of the expansion joint 80 can be adjusted by the area of ​​the joint 40, therefore, as Figure 1 and Figure 2 As shown, multiple areas with different area ratios of the joint portion 40 can be provided within the stretchable area 80 to vary the fit according to the location. Figure 1 and Figure 2 In the configuration shown, the area ratio of the plate joint 40 in the edge region 82 of the leg opening is higher than that in other regions, so the elongation stress is weaker, making it a region that can stretch and contract softly.

[0100] The shapes of the joint portions 40 and the joint holes 31 in their natural length state can be appropriately determined. They can be set to polygons such as circles, ellipses, triangles, rectangles, rhombuses, or arbitrary shapes such as convex lenses, concave lenses, stars, and clouds. The dimensions of the joint portions are not particularly limited. Regarding the maximum length 40y (which is approximately equal to the dimension 31y of the joint hole 31 in the vertical direction), it is preferably set to 0.5 to 3.0 mm, and particularly preferably set to 0.7 to 1.1 mm. Regarding the maximum width 40x, it is preferably set to 0.1 to 3.0 mm, especially in the case where the shape is longer in the direction XD perpendicular to the extension direction, it is preferably set to 0.1 to 1.1 mm.

[0101] The size of each joint 40 can be appropriately determined. However, if it is too large, the hardness of the joint 40 will have a greater impact on the tactile feel; if it is too small, the joint area will be reduced, and the materials will not be able to bond sufficiently. Therefore, it is generally preferable to set the area of ​​each joint 40 to approximately 0.14 to 3.5 mm. 2Regarding the area of ​​the openings of each joining hole 31, since the sheet joint portion is formed via the joining hole 31, it is sufficient to be above the sheet joint portion, but it is preferably set to approximately 1 to 1.5 times the area of ​​the sheet joint portion. Furthermore, the area of ​​the openings of the joining holes 31 does not refer to the value in the state of the elastic film 30 alone, but rather to the value in the state of being integrated with the first sheet layer 20A and the second sheet layer 20B, and in the state of natural length. When the area of ​​the openings of the joining holes 31 is different on the front and back sides of the elastic film 30, or is uneven in the thickness direction, the area of ​​the openings of the joining holes 31 refers to the minimum value.

[0102] The planar arrangement of the plate joint 40 and the joint hole 31 can be appropriately determined; however, a regularly repeating planar arrangement is preferred, except as shown below. Figure 10 The rhombic lattice or shown in (a) Figure 10 The hexagonal lattice pattern shown in (b) (these are also called interlaced patterns) Figure 10 The square grid pattern shown in (c) Figure 10 The rectangular grid pattern shown in (d) Figure 10 In addition to repeating the parallel grid pattern shown in (e) (as illustrated, groups of multiple parallel diagonal columns are arranged in a way that intersects each other to form two types of groups) (including shapes in which the groups of these diagonal columns are tilted at an angle of less than 90 degrees relative to the stretching direction), the groups of the sheet joint 40 (the arrangement of the group units can be regular or irregular, or they can be patterns or text, etc.) can also be repeated regularly.

[0103] The arrangement pattern of the sheet joint 40 in the telescopic region 80 is preferably... Figure 9 The example shown Figure 11 The examples shown and Figure 15 The arrangement pattern is as shown in the example. That is, in these examples, in the telescopic region 80, in the unfolded state, the first unjointed strips 51 and 52, which are continuous as parts without the piece joint 40, are repeatedly spaced apart in a direction perpendicular to the first direction 51d, which intersects the telescopic direction ED at an acute angle (acute angle side intersection angle θ1). In addition, a plurality of piece joints 40 and joint holes 31 are provided at intervals between adjacent first unjointed strips 51 in the telescopic region 80. Furthermore, the unit structure containing a plurality of first unjointed strips 51 with different first widths 51w is repeatedly present in the telescopic region 80 in a direction perpendicular to the first direction 51d, wherein the first width 51w is determined as the width in the direction perpendicular to the first direction 51d.

[0104] Thus, if multiple unit structures containing different first unjointed bands 51 of the first width 51w repeatedly exist in the telescopic region 80 in a direction perpendicular to the first direction 51d, the same width variation in size relationship will also be formed on the continuous portion of the elastic sheet 30 inside the first unjointed band 51. That is, if the width 51w of the first unjointed band 51 narrows, the width of the continuous portion of the inner elastic sheet 30 also narrows; if the width 51w of the first unjointed band 51 widens, the width of the continuous portion of the inner elastic sheet 30 also widens. Furthermore, if there is a variation in the first width 51w for the continuous portion of the elastic sheet 30 within the first unjointed band 51, both the continuous portion of the elastic sheet 30 within the wider first unjointed band 51 and the continuous portion of the elastic sheet 30 within the narrower first unjointed band 51 will be visually emphasized. As a result, regardless of the natural length state of the telescopic region 80 (refer to...),... Figure 13 and Figure 17 Whether the garment is stretched to a certain extent or not, it will still present a beautiful diagonal stripe pattern. In addition, when it is stretched to a certain extent, the size of the contraction pleat 25 at the first unjointed band 51 changes in correspondence with the first width 51w of the first unjointed band 51. Therefore, the diagonal stripe pattern appears more clearly due to the influence of the contraction pleat 25.

[0105] The aforementioned unit structure is not limited by the size of the first unjointed bands 51 as long as it includes multiple first unjointed bands 51 with different first widths 51w. However, when the first width 51w of the first unjointed band 51 is larger than the first unjointed band 51 with the closest width 51w, it is preferable that the former is 1.2 to 60 times the latter. When it is smaller, it is preferable that the former is 0.01 to 0.8 times the latter.

[0106] In addition, as long as the above-mentioned unit structure contains a plurality of first unjointed bands 51 with different first widths 51w, the first widths 51w of all the first unjointed bands 51 can be different, or as shown in the figure, the first widths 51w of a portion of the plurality of first unjointed bands 51 can be different from the first widths 51w of the other single or plurality of first unjointed bands 51.

[0107] Even if a diagonal stripe pattern along the first direction 51d appears in the expansion region 80, formed by the constriction fold 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside it, the diagonal stripe pattern formed by the constriction fold 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside it may become less noticeable if diagonal stripe patterns along other inclined directions are more strongly seen in the same expansion region 80. Therefore, it is preferable if the maximum value of the first width 51w of the first unjointed band 51 becomes the maximum value of the width of all unjointed bands 51, 52 with different and the same inclined directions in the direction perpendicular to the continuous direction, then the diagonal stripe pattern formed by the constriction fold 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside it will be more strongly seen in the expansion region 80. The maximum value of the first width 51w of the first unjointed strip 51 in this case can be appropriately determined, but it is preferably 0.01 to 9 times the width 51w of the first unjointed strip 51 closest to it. Furthermore, the width in the direction perpendicular to the continuous direction is not limited for all unjointed strips 51 and 52, including the first unjointed strip 51, but is generally preferably in the range of 0.3 to 50 mm. Of course, regarding the width of the unjointed strips 51 and 52 in the direction perpendicular to the continuous direction, for the first unjointed strip 51, it is the first width 51w, and since it is a straight, continuous portion, it is of equal width.

[0108] The first interval 51s, determined by the spacing of adjacent first unjointed bands 51 in a direction perpendicular to the first direction 51d, can be appropriately determined. Therefore, this first interval 51s can be the same as, larger than, or smaller than the first width 51w of the adjacent first unjointed bands 51. As a preferred example, a configuration where the maximum value of the first width 51w of the first unjointed bands 51 in the unit structure is smaller than the maximum value of the first interval 51s can be described. In this way, by forming a large interval portion in the unit structure, the diagonal stripe pattern formed based on the contraction fold 25 of the first unjointed bands 51 and the continuity of the elastic sheet 30 within it is more strongly observed. The maximum value of the first width 51w of the first unjointed bands 51 in this case can be appropriately determined, but is preferably 0.01 to 9 times the maximum value of the first interval 51s. Furthermore, the spacing between all the unjoined strips 51 and 52, including the first unjoined strip 51, in the direction perpendicular to the continuous direction is not particularly limited, but in general, it is preferably in the range of 0.3 to 50 mm. Of course, the spacing between the unjoined strips 51 and 52 in the direction perpendicular to the continuous direction is the first interval 51s for the first unjoined strip 51, and is equal in the continuous direction.

[0109] In the expansion region 80, a second unjointed band 52, which is a continuous straight line along a second direction 52d that intersects the expansion direction ED at an acute angle (acute angle θ2) outside the first direction 51d, may exist repeatedly at intervals in a direction perpendicular to the second direction 52d, or it may not exist. A preferred embodiment of the second unjointed band 52 is that in the expansion region 80, the unjointed bands 51 and 52 are formed in a diagonal lattice pattern, where the first unjointed band 51 is a continuous portion of the diagonal lattice unjointed bands 51 and 52 in one direction, and the second unjointed band 52 is a continuous portion of the diagonal lattice unjointed bands 51 and 52 in another direction. In this case, the inclinations of the first direction 51d and the second direction 52d relative to the expansion direction ED are opposite in sign. Furthermore, as... Figure 11 The examples shown and Figure 15 As shown in the example, even if it does not have a continuous unjointed strip 51, 52 in the width direction WD (telescopic direction ED), by making the acute-angle side intersection angles θ1 and θ2 of the first direction 51d and the second direction 52d relative to the telescopic direction ED 5 to 45 degrees, particularly preferably 10 to 30 degrees, in the unfolded state of the telescopic region 80, the stretchability in the telescopic region 80 can be sufficiently ensured.

[0110] However, if the diagonal stripe pattern along the inclined direction of the second unjointed band 52 is seen more strongly in the same stretching area 80, the diagonal stripe pattern based on the contraction fold 25 of the first unjointed band 51 and the continuity of the elastic sheet 30 inside it may become less noticeable. Therefore, it is desirable that, in such a stretching area 80... Figure 15 In the example shown, where a second unjointed strip 52 is present, the second width 52w of the second unjointed strip 52, determined by its width in the direction perpendicular to the second direction, is always the same; alternatively, the sheet joint 40 may be configured without a second unjointed strip 52. Thus, within the expansion region 80, the diagonal stripe pattern formed by the contraction fold 25 of the first unjointed strip 51 and the continuity of the elastic sheet 30 within it is more strongly visible.

[0111] On the other hand, between adjacent first unjoined strips 51, the sheet joints 40 are arranged along the first direction 51d. In this case, for example, Figure 16 As shown, if all the joint portions 40 are formed into an elongated shape such that the acute angle θ3 of the long side direction relative to the direction perpendicular to the stretching direction ED is within 10 degrees, and the maximum dimension 40e in the stretching direction ED is 0.1 to 0.4 mm, then the dimension of the first unjointed strip 51 in the stretching direction ED can be better ensured, thereby suppressing the reduction of stretchability, which is therefore preferred.

[0112] In addition, such as Figure 11 As shown in the example, in the unit structure, there are a plurality of wide first unjointed strips 51 with the largest first width 51w and a plurality of narrow first unjointed strips 51 with a first width 51w that are narrower than the first width 51w, which are arranged adjacent to each other in a direction perpendicular to the first direction 51d. In this case, it is preferable that between adjacent wide first unjointed strips 51, there are elongated sheet joints 40 arranged at intervals in the first direction 51d, which are such that the acute angle of the long side direction relative to the second direction 52d is within 5 degrees, and the maximum size 40f in the direction perpendicular to the long side direction is 0.1 to 0.4 mm. Furthermore, it is preferable that, between adjacent narrow first unjointed strips 51, elongated sheet joints 40 are arranged at intervals along the first direction 51d, such that the acute-angle intersection angle θ3 of the long side direction relative to the first direction 51d is 45 degrees or more, and the maximum dimension 40g in the direction perpendicular to the long side direction is 0.1 to 0.4 mm. Through this shape and arrangement of the sheet joints 40, the constriction folds 25 of the first unjointed strips 51 and the continuity of the elastic sheets 30 within them are visually emphasized with a smaller area of ​​the sheet joints 40.

[0113] The columns of the sheet joints 40 located between adjacent unjointed strips 51 and 52 (columns in the continuous direction of the unjointed strips 51 and 52) can be one column or multiple columns. In addition, the spacing of the sheet joints 40 in the column direction is preferably regular, but it is not necessary to make all the spacings fixed, and some of the spacings can be different.

[0114] (Non-expandable area)

[0115] In the region of the outer body 20 with the elastic sheet telescopic structure 20X, such as Figure 2 As shown, a non-stretchable region 70 can be provided on at least one side of the stretchable region 80 in the width direction. The non-stretchable region 70 refers to a region with a maximum stretch rate of 120% or less in the stretching direction. The maximum stretch rate of the non-stretchable region 70 is preferably 110% or less, more preferably 100%. The configuration of the stretchable region 80 and the non-stretchable region 70 can be appropriately determined. In the case of the outer casing 20 of this shorts-type disposable diaper, the portion overlapping with the absorbent body 13 is a region that does not require stretching. Therefore, it is preferable to use part or all of the portion overlapping with the absorbent body 13 (ideally including almost the entirety of the inner and outer fixing regions 10B) as the non-stretchable region 70, as illustrated. Of course, the non-stretchable region 70 can also be provided from the region overlapping with the absorbent body 13 all the way to the region that does not overlap with the absorbent body 13 in the width direction WD or the front-back direction LD, or only in the region that does not overlap with the absorbent body 13.

[0116] The shape of each piece joint 40 in the non-telescopic region 70 is not particularly limited, and can be appropriately selected from the same shape as that described in the section on the telescopic region 80.

[0117] Furthermore, the area ratio of the sheet joint 40 in the non-stretchable region 70 and the area of ​​each sheet joint 40 can be appropriately determined. However, under normal circumstances, if it is set within the following range, the area of ​​each sheet joint 40 is smaller and the area ratio of the sheet joint 40 is lower. As a result, the non-stretchable region 70 will not become hard, which is preferred.

[0118] Area of ​​the joint 40: 0.10~0.75mm 2 (A preferred size is 0.10–0.35 mm) 2 )

[0119] The area ratio of the joint 40 is 4-13% (particularly preferred to be 5-10%).

[0120] The non-stretchable region 70 can be formed by densely arranging the sheet joints 40 to prevent the first and second sheets from shrinking due to the contractile force of the elastic sheet 30, thus preventing the formation of folds. Specific examples of methods for forming the non-stretchable region 70 include those shown in Japanese Patent Nos. 5980355, 5918877, 5980367, and 6049228.

[0121] The stretching characteristics can be changed by varying the area ratio of the sheet joint 40. However, if the area ratio of the sheet joint 40 changes drastically at the point where the stretching region 80 and the non-stretching region 70 change along a vertical direction XD perpendicular to the stretching direction ED from one end to the other, then during welding, the linear pressure changes drastically at the boundary between the stretching region 80 and the non-stretching region 70. Such a drastic change in linear pressure may lead to premature wear or damage to equipment such as support rollers. Therefore, it is preferable that the area ratio of the sheet joint 40 in the stretching region 80 is 0.5 to 1 times that in the non-stretching region 70. Figure 2 , Figures 18-20 As shown, the boundary 71 between the telescopic region 80 and the non-telescopic region 70 has a shape that continuously shifts only to one side of the telescopic direction ED as it moves from one end to the other. Therefore, there is no abrupt change in line pressure during welding, thus reducing concerns about premature wear or damage to equipment such as support rollers.

[0122] However, in shorts-type disposable garments, if the boundary 71 between the stretchable area 80 and the non-stretchable area 70 is shaped such that it continuously shifts only towards the center of the width direction WD from the end on the waist opening side towards the center of the disposable garment in the front-rear direction LD, then the stretchable area 80 on the waist opening side becomes shorter, which is not preferable from the viewpoint of ensuring a good fit. Therefore, it is preferable that, as shown in the example, the position of the boundary 71 between the stretchable area 80 and the non-stretchable area 70 continuously shifts only towards the side closure 21 from the end on the waist opening side towards the center of the disposable garment in the front-rear direction LD.

[0123] The boundary 71 between the stretchable region 80 and the non-stretchable region 70 can be as follows: Figure 2 , Figure 18 as well as Figure 20 The example shown is a straight line, but it can also be like... Figure 19 The example shown is curved. Figure 20 As shown in the example, a recess 72 is formed on the waist opening side of the non-stretchable region 70, recessed towards the crotch side. When this recess 72 is designated as the stretchable region 80, boundaries 71 between the stretchable region 80 and the non-stretchable region 70 are formed on both sides of the stretching direction ED of the recess 72. Therefore, for this part, it is desirable to also designate the boundary 71 between the stretchable region 80 and the non-stretchable region 70 as oblique.

[0124] (Joint structure of the plate joint)

[0125] In the case where the engagement of the first sheet layer 20A and the second sheet layer 20B in the sheet joint 40 is performed through the engagement hole 31 formed in the elastic sheet 30, it is desirable that the first sheet layer 20A and the second sheet layer 20B are not engaged with the elastic sheet 30, at least not between the first sheet layer 20A and the second sheet layer 20B in the sheet joint 40.

[0126] When the first sheet layer 20A and the second sheet layer 20B are fused together through the joining hole 31 of the elastic sheet 30 at the sheet joint 40, both the first sheet layer 20A and the second sheet layer 20B can be melted and solidified at the sheet joint 40, or only one of the first sheet layer 20A and the second sheet layer 20B can be melted and solidified at the sheet joint 40. Moreover, the molten and solidified material of the elastic sheet 30 can be sandwiched within the sheet joint 40.

[0127] Layer 1 20A and Layer 20B can be as follows: Figure 8 As shown in example (a), the entire thickness and planar direction of the sheet joint 40 can be uniformly melted and solidified, as in... Figure 8 As shown in (b) and (c), the melting and solidification are uneven, as indicated by the dotted tones. For example, as... Figure 8As shown in example (b), the first layer 20A and the second layer 20B can be such that the degree of melting is lower the closer they are to the outer side of the thickness direction of the sheet joint 40. This state includes the following conditions: almost all the fibers of the first layer 20A and the second layer 20B are not melted on the surface of the sheet joint 40; the molten solidified material of the first layer 20A and the second layer 20B is mixed with the unmelted fibers on the surface of the sheet joint 40; and the fibers of the first layer 20A and the second layer 20B are melted throughout the entire thickness direction of the sheet joint 40, but the degree of melting varies.

[0128] This could be due to changes in the degree of melting in the thickness direction at the aforementioned sheet joint 40, or unrelated to this, such as... Figure 8 As shown in example (c), the degree of melting of the first sheet layer 20A and the second sheet layer 20B is lower closer to the periphery of the sheet joint 40. This state includes the following conditions: at the periphery of the sheet joint 40, almost all the fibers of the first sheet layer 20A and the second sheet layer 20B are not melted (wherein, limited to the case where the molten solidified material of the elastic sheet 30 described later is sandwiched therein as an adhesive); at the periphery of the sheet joint 40, the molten solidified material of the first sheet layer 20A and the second sheet layer 20B is mixed with unmelted fibers; and, throughout the entire planar direction of the sheet joint 40, although the fibers of the first sheet layer 20A and the second sheet layer 20B are melted, the degree of melting varies.

[0129] Furthermore, in these states, the situation regarding the melting of fibers in the first layer 20A and the second layer 20B includes not only the overall melting of the fibers, but also the situation where the core of the fiber (including not only the core in the composite fiber, but also the central part of the single-component fiber) remains, but the surrounding part (including not only the sheath in the composite fiber, but also the surface side of the single-component fiber) melts.

[0130] Furthermore, the state in which the molten solidified material of the elastic sheet 30 remains within the sheet joint 40 includes the following states: between the first sheet layer 20A or its molten solidified layer and the second sheet layer 20B or its molten solidified layer, the molten solidified material of the elastic sheet 30 remains in a layered manner with almost no mixing with them; the molten solidified material of the elastic sheet 30 is mixed with the molten solidified sheets in the first sheet layer 20A and the second sheet layer 20B; and the molten solidified material of the elastic sheet 30 permeates to a certain extent between the fibers of the unmelted solidified sheets in the first sheet layer 20A and the second sheet layer 20B, or permeates between the remaining fibers (including the core) of the molten solidified sheets in the first sheet layer 20A and the second sheet layer 20B.

[0131] The state in which the molten solidified material of the elastic sheet 30 remains in the sheet joint 40 can be manufactured by: under the condition that the melting point of at least one of the first sheet layer 20A and the second sheet layer 20B is higher than the melting point of the elastic sheet 30, the elastic sheet 30 is sandwiched between the first sheet layer 20A and the second sheet layer 20B, and pressure / heat is applied to the portion that forms the sheet joint 40, so that at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic sheet 30 melt.

[0132] In this case, the melting point of the elastic sheet 30 is preferably about 80 to 145°C, and the melting points of the first layer 20A and the second layer 20B are preferably about 85 to 190°C, particularly preferably about 150 to 190°C. The difference between the melting points of the first layer 20A and the second layer 20B and the melting point of the elastic sheet 30 is preferably about 60 to 90°C. Furthermore, the heating temperature is preferably about 100 to 150°C.

[0133] Figure 21 An example of a preferred ultrasonic sealing device is shown. In this ultrasonic sealing device, when forming the sheet joint 40, a first sheet layer 20A, an elastic sheet 30, and a second sheet layer 20B are fed between a support roller 60 and an ultrasonic welding head 61. The support roller 60 has protrusions 60a formed on its outer surface according to the pattern of the sheet joint 40. At this time, for example, by making the feeding speed of the upstream elastic sheet 30 based on the feeding drive roller 63 and the clamping roller 62 slower than the feeding speed after the support roller 60 and the ultrasonic welding head 61, the elastic sheet 30 is elongated to a predetermined elongation rate in the MD direction (machine direction, conveying direction) along the path from the clamping position based on the feeding drive roller 63 and the clamping roller 62 to the sealing position based on the support roller 60 and the ultrasonic welding head 61. The elongation rate of the elastic sheet 30 can be set by selecting the speed difference between the support roller 60 and the feeding drive roller 63, for example, it can be set to approximately 300% to 500%. 62 is a pinch roller.

[0134] The first layer 20A, the elastic sheet 30, and the second layer 20B, fed between the support roller 60 and the ultrasonic welding head 61, are stacked in this order. While being pressed between the protrusion 60a and the ultrasonic welding head 61, they are heated by the ultrasonic vibration energy of the ultrasonic welding head 61, causing either the elastic sheet 30 to melt, or at least one of the first layer 20A and the second layer 20B along with the elastic sheet 30 to melt. This forms a joining hole 31 on the elastic sheet 30. Simultaneously, the first layer 20A and the second layer 20B are joined together by passing through this joining hole 31. Therefore, in this case, by selecting the size, shape, separation interval, roller length direction, and circumferential arrangement pattern of the protrusion 60a of the support roller 60, the area ratio of the sheet joint 40 can be selected.

[0135] The reason for forming the joining hole 31, while not necessarily clear, can be considered as follows: the portion of the elastic sheet 30 corresponding to the protrusion 60a of the support roller 60 melts and detaches from its surroundings, thereby creating the hole. At this time, as... Figure 7 (a), (b) Figure 9 (a), (b) Figure 12 as well as Figure 13 As shown, the portion of the elastic sheet 30 between adjacent engagement holes 31 arranged side by side in the telescopic direction ED is cut off from the portions on both sides of the telescopic direction by the engagement holes 31, thus losing the support on both sides of the contraction direction. Therefore, within the range that can maintain continuity in the direction perpendicular to the contraction direction, the closer to the center side of the direction LD perpendicular to the telescopic direction ED, the more it contracts towards the center side of the telescopic direction until it reaches equilibrium, thereby enlarging the engagement hole 31 in the telescopic direction ED.

[0136] Regarding the constituent materials of the first layer 20A and the second layer 20B, any nonwoven fabric in which at least a portion of the fibers can be welded (i.e., containing a thermoplastic resin component) can be used without particular limitation. Examples include olefin-based, polyester-based, polyamide-based, and other synthetic fibers such as polyethylene or polypropylene, blended fibers using two or more of these, or composite fibers containing two or more of these components (e.g., core-sheath type composite fibers where the sheath component is easily melted). Furthermore, the nonwoven fabric can be manufactured through any processing.

[0137] Regarding the methods of fiber bonding in nonwoven fabrics, chemical methods such as adhesives or solvents, physical methods such as heating, and any method of interlacing can be used, such as hydroentangling, spunbonding, thermal rolling, meltblowing, needle punching, hot air bonding, and spot bonding. When using nonwoven fabrics, the preferred weight per unit area is approximately 10–25 g / m². 2 Furthermore, part or all of the first layer 20A and the second layer 20B can be a pair of layers formed by folding back and opposing a single sheet of material. For example, as shown in the diagram, at the waist end 23, the outer component is the second layer 20B, and the folded portion 20C, formed by folding back towards the inner surface at the waist opening edge, is the first layer 20A, with the elastic sheet 30 positioned between them. In the portion outside the waist end 23, the inner component is the first layer 20A, and the outer component is the second layer 20B, with the elastic sheet 30 positioned between them. Alternatively, the components of the first layer 20A and the second layer 20B can be arranged separately throughout the entire front-rear direction LD, without folding back the components, with the elastic sheet 30 positioned between the components of the first layer 20A and the second layer 20B.

[0138] The elastic sheet 30 is not particularly limited; it can be any sheet made of thermoplastic resin that is inherently elastic, and can be either an elastic (stretch) film or a stretch nonwoven fabric. Furthermore, in addition to non-porous sheets, sheets with multiple holes or slits can be used as the elastic sheet 30 for breathability. Particularly preferred is an elastic sheet 30 with the following tensile strength: 8–25 N / 35 mm in the width direction WD (stretch directions ED, MD), 5–20 N / 35 mm in the front-to-back direction LD (directions perpendicular to the stretch directions XD, CD), 450–1050% elongation in the width direction WD, and 450–1400% elongation in the front-to-back direction LD. The thickness of the elastic sheet 30 is not particularly limited, but is preferably approximately 20–40 μm.

[0139] (A combination of plates of different shapes)

[0140] In areas with elastic sheet telescopic structures 20X, sheet joints 40 of different shapes can be provided to change telescopic characteristics or appearance. For example, Figure 11 The example shown illustrates that the sheet joint 40 of the telescopic region 80 includes rectangular sheet joints 40 with different orientations; however, such sheet joints 40 with different orientations are also included in sheet joints 40 with different shapes. Furthermore, Figure 15 The example shown shows that the sheet joint 40 of the telescopic region 80 includes rectangular sheet joints 40 of different lengths; however, such sheet joints 40 of different lengths are also included in sheet joints 40 of different shapes. In addition, the case where the shape of the sheet joint 40 of the telescopic region 80 is different from the shape of the sheet joint 40 of the non-telescopic region 70 also falls under the category of "the region having the elastic sheet telescopic structure 20X has sheet joints 40 of different shapes".

[0141] In the case of a disposable shorts-type garment as shown in the example, it is preferable to provide an elastic stretch structure 20X extending from the center L to the waist T in the front-to-back direction LD and across the side closures 21 in the width direction WD. This creates a difference in the stretchability and appearance of the leg opening edge region 82 compared to other areas, thereby improving the fit of the leg opening and other areas. Thus, for example, as in... Figure 22 As shown in the enlarged view, the shape of the plate joint 40 in the edge region 82 along the leg opening can be different from the shape of the plate joint 40 in other regions.

[0142] In cases where sheet joints 40 of different shapes are provided in areas with elastic sheet telescopic structures 20X, as previously mentioned, poor welding may occur, or premature wear or breakage of equipment such as support rollers may result. Therefore, it is desirable that for all sheet joints 40 in the area with elastic sheet telescopic structures 20X, the joint reference diameter is [missing information]. For diameters greater than 0.2mm, the joint reference diameter The maximum value is 1 to 3 times the minimum value, and the perimeter is based on the joint reference diameter. The circumference of the joint portion 40 is 1 to 15 times the diameter of the circle. The meaning of each value is as described above. That is, when the diameter of the joint reference is less than 0.2 mm, poor welding is generally likely to occur. Furthermore, excessively long or overly complex shapes of the joint portion 40 are prone to partial welding defects. From this viewpoint, it is preferable that the circumference of the joint portion 40 is within the aforementioned range. Additionally, the diameter of the joint reference of the joint portion 40... If the difference is too large, the wire compression when forming the joint portion 40 should conform to the joint reference diameter. Large joints (40mm) are prone to poor welding. Additionally, based on the joint reference diameter... When a small piece joint 40 is used to increase the linear pressure when forming the piece joint 40, it may cause premature wear or damage to equipment such as support rollers.

[0143] Here, the joint reference diameter This refers to the diameter of the largest inscribed circle 40c that is tangent to the outer shape of the joint portion 40. Therefore, as... Figure 24 As shown in (a) and (b), the joint reference diameter of the elongated plate joint 40 Smaller than the major axis, such as Figure 24 As shown in (c) and (d), the joint reference diameter of the plate joint 40, which is nearly circular in shape such as a circle or a regular pentagon, is... It is almost equal to the major axis. For example... Figure 24 As shown in (e), in the case of the L-shaped piece joint 40, the joint reference diameter It is also smaller than the major diameter. Based on these examples, although not illustrated, the joint reference diameter of the complex-shaped plate joint 40, such as the star shape, is... It's also a bit small.

[0144] As long as the reference diameter is joined The dimensions can be within the above range; however, as a preferred example, it is preferable that the first and second layers have a linear density of 0.7–6 dtex and a weight per unit area of ​​10–25 g / m². 2 In the case of nonwoven fabric, the joint reference diameter of all sheet joints 40 in the area with elastic sheet stretch structure 20X The diameter is 0.2–0.8 mm. This allows for the suppression of poor welding while preventing premature wear and breakage of the equipment. A more preferred joint reference diameter is... The range is 0.25 to 0.5 mm.

[0145] In the plate joints 40 with different shapes, the joint reference diameter It is possible Figure 22 Unlike the example shown, it can also be like... Figure 23 It is the same as shown.

[0146] Regarding the line pressure that affects poor weld bonding in ultrasonic sealing, it can be adjusted by applying pressure. Therefore, in order to reliably prevent poor weld bonding, it is desirable that all sheet joints 40 formed by a single ultrasonic welding head meet the above conditions. Similarly, in the case of heat sealing, it is desirable that all sheet joints 40 formed by a pair of support rollers and opposing rollers meet the above conditions.

[0147] <Explanation of terms used in the instruction manual>

[0148] Unless otherwise specified in the instruction manual, the following terms in the instruction manual shall have the following meanings.

[0149] "Front part" and "back part" refer to the portions located on the front and back sides, respectively, with the center of the shorts-type disposable diaper as the boundary. Additionally, the crotch area refers to the area in the front-back direction including the center of the shorts-type disposable diaper; if the absorbent body has a narrowing portion, it refers to the area in the front-back direction of the portion with that narrowing portion.

[0150] "Maximum stretch rate" refers to the maximum stretch rate in the stretch direction ED (in other words, the stretch rate in the unfolded state where the first and second layers are unfolded without contraction or loosening), and is expressed as a percentage of the unfolded length when the natural length is 100%.

[0151] "Area ratio" refers to the proportion of an object portion in a unit area. It is a percentage calculated by dividing the total area of ​​object portions (e.g., the joint portion 40, the opening of the joint hole 31, and the vent hole) in the object region (e.g., the telescopic region 80 and the non-telescopic region 70) by the area of ​​the object region. In particular, the "area ratio" in a region with a telescopic structure refers to the area ratio in the unfolded state. In a configuration where multiple object portions are spaced apart, it is desirable to set the object region to contain more than 10 object portions and then calculate the area ratio.

[0152] "Elongation" refers to the value when the natural length is set to 100%.

[0153] The "weight per unit area" is measured as follows: After pre-drying, the sample or test piece is placed in a test chamber or apparatus under standard conditions (temperature 23±1℃, relative humidity 50±2%) to achieve a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight state at an environment of 100℃. Alternatively, for fibers with a standard moisture regain of 0.0%, pre-drying may not be necessary. Using a template (100mm×100mm) for sample selection, cut 100mm×100mm samples from the constant-weight test piece. Measure the weight of the sample, and calculate the weight per square meter as the weight per unit area, multiplied by 100.

[0154] The "thickness" of the absorber is measured using a thickness gauge (PEACOCK, dial thickness gauge, large type, model JB (measuring range 0-35mm) or model K-4 (measuring range 0-50mm)) from Ozaki Manufacturing Co., Ltd., with the sample and the thickness gauge level.

[0155] The "thickness" other than those mentioned above is measured using an automatic thickness gauge (KES-G5 portable compression measurement program) under a load of 0.098 N / cm. 2 The pressure area is 2cm² 2 It is automatically measured under certain conditions.

[0156] "Tensive strength" and "tensile elongation (elongation at break)" refer to the values ​​measured according to JIS K7127:1999 "Plastics - Test methods for tensile properties," with an initial inspection interval (scale distance) of 50 mm and a tensile speed of 300 mm / min, in addition to setting the test piece to a rectangular shape with a width of 35 mm and a length of 80 mm. For example, the AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used as a tensile testing machine.

[0157] "Elongation stress" refers to the tensile stress (N / 35mm) measured during elongation within the elastic region in a tensile test conducted according to JIS K7127:1999 "Plastics - Test methods for tensile properties -", ​​with an initial inspection interval (scale distance) of 50mm and a tensile speed of 300mm / min. The degree of elongation can be appropriately determined based on the test object. Regarding the test piece, it is preferable to set it to a rectangular shape with a width of 35mm and a length of 80mm or more. However, if a test piece with a width of 35mm cannot be cut, a test piece of the width that can be cut should be made, and the measured value should be converted to the value under the condition of a 35mm width. Furthermore, even if the target area is small and sufficient test pieces cannot be obtained, if the magnitude of the elongation stress is to be compared, it is still possible to make a comparison by appropriately using test pieces that are small but of the same size. For example, the AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used as a tensile testing machine.

[0158] "Unfolded state" refers to a state in which the body is flat and unfolded without shrinking or relaxing.

[0159] Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not in the natural length state.

[0160] Unless otherwise specified, the test or measurement was conducted in a laboratory or apparatus under standard conditions (temperature 23±1℃ and relative humidity 50±2%).

[0161] Industrial availability

[0162] Regarding this invention, as long as it is an article with a stretchable area that can utilize an elastic sheet stretchable structure, in addition to the shorts-type disposable diapers as described above, this invention can also be used in the stretchable components of all disposable clothing items, such as belt-type, pad-type, and other disposable diapers, sanitary napkins, and disposable clothing items for swimming or water play.

[0163] Label Explanation

[0164] 10: Inner body; 10B: Inner and outer fixing areas; 11: Top sheet; 12: Liquid-impermeable sheet; 13: Absorbent body; 13N: Narrowing section; 14: Packaging sheet; 17: Side without absorbent body; 20: Outer body; 20A: First sheet layer; 20B: Second sheet layer; 20C: Fold-back section; 20X: Elastic sheet telescopic structure; 21: Side seal; 23: Waist end area; 24: Waist elastic component; 25: Shrink fold; 29: Leg circumference line; 30: Elastic sheet; 31: Joint hole; 40: Sheet joint; 51, 52 51: No joint strip; 51d: First no joint strip; 51s: First interval; 51w: First width; 52: Second no joint strip; 52d: Second direction; 70: Non-stretchable area; 80: Stretchable area; 90: Three-dimensional pleat section; 93: Folded-down section; 94: Free section; 95: Pleated piece; 96: Elastic stretchable component of pleat section; B: Back section; ED: Stretch direction; F: Front section; L: Middle section; LD: Front and back direction; T: Waist section; WD: Width direction; 71: Boundary; : Joint reference diameter.

Claims

1. A telescopic component, characterized in that, The telescopic component has an elastic sheet telescopic structure as follows: the elastic sheet is located between a first layer made of nonwoven fabric and a second layer made of nonwoven fabric, and the first layer and the second layer are fused together through a through-hole in the elastic sheet at a plurality of spaced-apart joints. The region having the elastic sheet telescopic structure has a telescopic region, which contracts in the telescopic direction by means of the contraction of the elastic sheet, and is also capable of elongating in the telescopic direction. In the telescopic region, a first unjointed band that does not have the piece joint is continuously linear along a first direction that intersects the telescopic direction at an acute angle, and is repeatedly spaced apart in a direction perpendicular to the first direction. Between adjacent first unjointed strips, the sheet joints are arranged at intervals in the first direction, and the sheet joints between adjacent first unjointed strips are all formed as elongated as follows: the acute angle of the long side direction relative to the direction perpendicular to the telescopic direction is within 10 degrees, and the maximum dimension in the telescopic direction is 0.1mm to 0.4mm.

2. The telescopic component according to claim 1, wherein, The telescopic region is a region formed in the unfolded state by a continuous, unjointed strip in a diagonal grid pattern, where the portion without the plate joint does not exist. The oblique lattice-shaped unjointed band is composed of the first unjointed band and the second unjointed band. The second unjointed band is continuous in a straight line in a second direction other than the first direction, intersecting the stretching direction at an acute angle, and is repeatedly spaced apart in a direction perpendicular to the second direction. Between adjacent second unjointed strips, the plate joints are arranged at intervals in the second direction. The inclinations of the first direction and the second direction relative to the telescopic direction are opposite in sign to each other. In the extended state of the telescopic region, the acute-angle intersection angles of the first direction and the second direction relative to the telescopic direction are greater than 0 degrees and less than 45 degrees.

3. The telescopic component according to claim 2, wherein, Within the telescopic region, multiple unit structures comprising the first unjointed bands of varying first widths repeatedly exist in a direction perpendicular to the first direction, wherein the first width is determined as the width in the direction perpendicular to the first direction. In the unit structure, there are multiple wide first unjointed strips with the largest first width and multiple narrow first unjointed strips with a width narrower than the wide first unjointed strips, arranged adjacently in a direction perpendicular to the first direction. Between adjacent wide first unjointed strips, elongated sheet joints are arranged at intervals in the first direction, with the following characteristics: the acute angle of the long side direction relative to the second direction is within 5 degrees, and the maximum dimension in the direction perpendicular to the long side direction is 0.1 mm to 0.4 mm. Between adjacent narrow first unjointed strips, elongated sheet joints are arranged at intervals in the first direction, such that the acute angle of the long side direction relative to the first direction is 45 degrees or more, and the maximum dimension in the direction perpendicular to the long side direction is 0.1 mm to 0.4 mm.

4. A disposable garment, characterized in that, The disposable garment is a shorts-type disposable garment, comprising: an integral outer body extending from the front to the back, or outer bodies separately disposed in the front and back portions; an inner body installed in the middle of the width of the outer body and extending to the front and back sides of the crotch portion; side closures formed by joining the sides of the outer body in the front portion and the sides of the outer body in the back portion together; and a waist opening and a pair of leg openings, wherein... The outer body of the front part and the outer body of the rear part are telescopic components that have the elastic sheet telescopic structure of claim 1, which extends across the side seals in the width direction, and the telescopic direction of the telescopic area of ​​the elastic sheet telescopic structure is the width direction.

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