Tape-type disposable diapers

Abstract

To provide a tape type disposable diaper having high peel strength of a connection tape, and excellent in fitting property.SOLUTION: In a tape type disposable diaper, a connection tape 13 has a base end part 13C fixed to a wing part WF, and an extension part 13B extending from the base end part 13C to a width direction outer side. A shape of the extension part 13B of the connection tape 13 forms a shape in which a length in a longitudinal direction is narrowed in a step form from a base end side toward a tip side. A length in the longitudinal direction in a width direction intermediate part of the extension part 13B is 15 mm-45 mm, a length in the longitudinal direction in the width direction intermediate part of the extension part 13B is the same length in any point in the width direction, or is different in any point in the width direction, a difference between a longest part and a shortest part lies in a range of 2.0 mm, and at least the width direction intermediate part of the connection tape 13 is provided with a connection part 13A for fixing the connection tape 13 to the outside surface of a belly side part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a tape-type disposable diaper having a connecting tape with improved fit. [Background technology]

[0002] There are three main types of disposable diapers: tape type, pants type, and pad type. Of these, tape type disposable diapers are worn by first placing them on the body in an unfolded state and then connecting the connecting parts on both the left and right sides of the dorsal part to the outer surface of the abdominal part.

[0003] A typical tape-type disposable diaper has a crotch portion including the center in the front-rear direction, a ventral portion extending forward from the center in the front-rear direction, and a dorsal portion extending backward from the center in the front-rear direction, at least the dorsal portion has wing portions extending outward on both the left and right sides in the width direction beyond the crotch portion, the ventral portion and the dorsal portion have intermediate portions located between the left and right wing portions, and the wing portions have connecting tapes detachably connected to the outer surface of the ventral portion. When in use, the wing portions are turned from both sides of the waist to the outer surface of the ventral portion, and the connecting tapes provided on the outer sides of the wing portions in the width direction are connected to the outer surface of the ventral portion. Such tape-type disposable diapers are used not only for infants but also for nursing care (for adults).

[0004] Conventionally, shapes of connecting tapes (also called "fastening tapes"; the same applies below) for tape-type disposable diapers are disclosed in the following Patent Documents 1 and 2. The fastening tape of Patent Document 1 comprises a fixing part that is fixed to the diaper and a fastening part that is connected to the fixing part, the fastening part has a stopper part, and the periphery of the fastening part is composed of a base edge that is located closest to the fixing part and crosses the fastening tape in its width direction, a tip edge that is located farthest from the fixing part and crosses the fastening tape in its width direction, and left and right side edges that are formed to approximately coincide with the left and right side edges of the fastening part, the width X of the tip edge is 15 to 40 mm, and the width Y of the base edge is 25 to 55 mm. m, the ratio X / Y of the width X to the width Y is 0.40 to 0.80, the fastening tape comprises a tape base material made of a nonwoven fabric and a convex member of a mechanical fastener fixed onto the tape base material, the fastening portion being formed by the convex member, the fastening tapes being mirror images of each other, and when a plurality of fastening tapes of one fastening tape are arranged so that the left and right side edges of the fixing portion are connected, a part of the outline formed by these tapes matches the outline of the fastening portion of the other fastening tape. The fastening tape described in Patent Document 1 is shown in Figure 7(b).

[0005] On the other hand, the fastening tape described in Patent Document 2 comprises a base sheet connected to side flaps, and a hook sheet fixed to the base sheet, the hook sheet having a plurality of engaging members that engage with a front waist region, the base sheet having a joint joined to the side flaps and a tip extending outward in the product width direction beyond the hook sheet, the length of the tip in the product width direction is 5 to 12 mm, the distance in the product longitudinal direction between the outer end of the joint and the outer end of the hook sheet in the product longitudinal direction is 2 to 12 mm, the length in the product longitudinal direction at the boundary between the hook sheet and the tip is at least twice the distance in the product longitudinal direction between the inner end of the base sheet in the product longitudinal direction and the inner end of the hook sheet in the product longitudinal direction, and the hook sheet extends outward in the product longitudinal direction beyond the midpoint between the outer end of the hook sheet in the product longitudinal direction at the inner end of the hook sheet in the product width direction and the outer end of the tip in the product longitudinal direction at the inner end of the tip in the product width direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4014267 [Patent Document 2] Patent No. 5291234 Summary of the Invention [Problem to be solved by the invention]

[0007] In the fastening tape described in Patent Document 1, the length of the hook material in the front-rear direction varies greatly in the widthwise intermediate region of the fastening tape. That is, in the widthwise intermediate region, the fastening tape has a curved shape from the base end side to the tip side, and tapers toward the tip. This reduces the peel strength between the fastening tape and the ventral outer surface of the disposable diaper. This reduction in peel strength is particularly noticeable in the widthwise intermediate region. If the peel strength in the widthwise intermediate region is low, the fastening tape will peel off easily even if the peel strength in other regions is high, so there is a problem that consumers feel anxious that the fastening tape will peel off easily when attaching or removing it.

[0008] The fastening tape described in Patent Document 2 has a large area in the widthwise middle region, and therefore does not have the problems of Patent Document 1. However, since it does not have a bilaterally symmetrical (mirror image) shape as in Patent Document 1, there is a problem that cut pieces of the fastening tape end up as waste when manufacturing diapers.

[0009] Other fastening tapes have a long, narrow rectangular shape, but if the length of the fastening tape in the front-to-rear direction is short in the portion from the widthwise inner edge of the hook sheet fixed to the fastening tape to the fixed edge of the fastening tape, then when the wearer of the disposable diaper moves his or her legs, this portion of the fastening tape is likely to become twisted in the front-to-rear direction.

[0010] Therefore, the primary object of the present invention is to provide a tape-type disposable diaper having a connecting tape with high peel strength and excellent fit. The secondary object of the present invention is to provide a tape-type disposable diaper in which the fastening tape is less likely to twist in the front-to-rear direction when worn, and the back side of the diaper is less likely to shift in the front-to-rear direction. [Means for solving the problem]

[0011] Various aspects of tape-type disposable diapers that solve the above problems are as follows. <First aspect> A crotch portion having both side edges extending from a middle of the ventral portion in the front-to-rear direction to a middle of the dorsal portion in the front-to-rear direction, and a ventral portion extending forward from a middle of the ventral portion in the front-to-rear direction, and a crotch portion having both side edges extending from a middle of the ventral portion in the front-to-rear direction to a middle of the dorsal portion in the front-to-rear direction, An absorbent body incorporated in an area including the crotch area; Wing portions extending outward in a width direction beyond the crotch portion on the ventral portion and the dorsal portion; The back portion has connecting tapes on both sides thereof for detachably connecting to the ventral portion. In tape-type disposable diapers, The connecting tape has a base end portion fixed to the wing portion and an extension portion extending outward in a width direction from the base end portion, The shape of the extension portion of the connecting tape is such that the length in the front-rear direction narrows in a stepped manner from the base end side to the tip end side, The length of the extension portion in the front-rear direction at the widthwise intermediate portion is 15 mm to 45 mm, The length in the front-rear direction of the widthwise intermediate portion of the extension portion is the same at any point in the widthwise direction, or the length varies depending on any point in the widthwise direction, and the difference between the longest part and the shortest part is within a range of 2.0 mm; A tape-type disposable diaper, characterized in that a connecting portion for fixing the connecting tape to an outer surface of the abdominal portion is provided at least in a widthwise intermediate portion of the connecting tape.

[0012] (Action and effect) By setting the front-rear length of the widthwise intermediate portion of the extension portion within a range of 15 mm to 45 mm, the front-rear length of the widthwise intermediate portion of the extension portion being the same length at any point in the width direction or varying in length at any point in the width direction, and setting the difference between the longest and shortest portions within a range of 2.0 mm, it is possible to increase the peel strength compared to the widthwise intermediate portion being greatly curved as in Patent Document 1. That is, by setting the difference between the longest and shortest portions within a range of 2.0 mm, the peel strength becomes approximately 160 gf to 180 gf, so that consumers are less likely to feel uneasy about the peel strength (uneasy about whether the connecting tape is securely fixed to the ventral outer surface).

[0013] <Second aspect> The tape-type disposable diaper according to the first aspect, wherein the length in the front-rear direction of the base portion of the extension portion is within a range of about 63% to 70% of the length in the front-rear direction of the base end portion.

[0014] (Action and effect) By setting the length of the root part of the extension part in the front-to-rear direction as described above, the root part of the extension part becomes thicker (the length in the front-to-rear direction becomes longer), so that it is possible to prevent the root part of the extension part from twisting. Specifically, when the length of the base end part in the front-to-rear direction is set to 50 mm to 75 mm, it is preferable that the length of the root part in the front-to-rear direction is set to 30 mm to 48 mm.

[0015] <Third aspect> The edge of one side in the front-rear direction of the connecting tape has a shape in which concave curves and convex curves are alternately arranged from the base end side to the tip end side, The tape-type disposable diaper according to the first aspect, wherein the connecting portion is disposed between a concave curve and a convex curve provided at both ends of the widthwise middle portion of the connecting tape.

[0016] (Action and effect) Since the connecting portion is contained between the concave curve and the convex curve provided at both ends of the width direction middle part of the connecting tape, when the wearer's foot comes into contact with the base part of the extension part, the base part is easily rolled up. Also, since there is no connecting portion at the base part, discomfort is reduced when the base part comes into contact with the foot. Effect of the Invention

[0017] According to the present invention, it is possible to provide a tape-type disposable diaper having a high peel strength of a connecting tape and excellent fit. It is also possible to provide a tape-type disposable diaper in which the fastening tape is less likely to twist in the front-to-rear direction when worn, and the back side of the diaper is less likely to shift in the front-to-rear direction. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a plan view showing the inner surface of the tape-type disposable diaper in an unfolded state. [Diagram 2] FIG. 2 is a plan view showing the outer surface of the tape-type disposable diaper in an unfolded state. [Diagram 3] 6 is a cross-sectional view taken along line 6-6 in FIG. 1. [Figure 4] 7 is a cross-sectional view taken along line 7-7 in FIG. 1. [Diagram 5] 1(a) is a cross-sectional view taken along line 8-8 in FIG. 1, and FIG. [Figure 6] 5 is a cross-sectional view taken along line 5-5 of FIG. 1. [Figure 7] 1A and 1B are plan views of a connecting tape according to the present invention and a conventional example, respectively. [Figure 8] 1A to 1C are plan views showing a manufacturing process of the connecting tape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1 to 6 show an example of a tape-type disposable diaper, in which the symbol X indicates the overall width of the diaper excluding the connecting tape, and the symbol L indicates the overall length of the diaper. The hot melt adhesive can be applied by known methods such as slot application, continuous line or dotted line bead application, spiral or Z-shaped spray application, or pattern coating (transfer of hot melt adhesive using a letterpress method). Alternatively or in addition to this, in the fixing portion of the elastic member, the hot melt adhesive can be applied to the outer circumferential surface of the elastic member to fix the elastic member to the adjacent member. As the hot melt adhesive, for example, EVA-based, adhesive rubber-based (elastomer-based), olefin-based, polyester / polyamide-based, and other types are available, but they can be used without any particular limitation. As a joining means for joining each component, material welding means such as heat sealing and ultrasonic sealing can also be used.

[0020] This tape-type disposable diaper has a ventral portion F extending forward from the center in the front-to-rear direction LD, and a dorsal portion B extending rearward from the center in the front-to-rear direction LD. This tape-type disposable diaper also has an absorbent body 56 incorporated in an area including the crotch area, a liquid-permeable top sheet 30 covering the front side of the absorbent body 56, a liquid-impermeable sheet 11 covering the back side of the absorbent body 56, and an exterior nonwoven fabric 12 covering the back side of the liquid-impermeable sheet 11 and constituting the outer surface of the product.

[0021] The materials and features of each part will be explained below in order. (Absorbent) The absorbent body 56 is a part that absorbs and retains excreted liquid, and can be formed by a fiber assembly. As this fiber assembly, in addition to stacked staple fibers such as cotton-like pulp and synthetic fibers, a filament assembly obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate as required can also be used. When stacking cotton-like pulp or staple fibers, the fiber weight is, for example, 100 to 300 g / m 2 In the case of a filament aggregate, for example, the weight is 30 to 120 g / m 2The fineness of the synthetic fibers is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament assembly, the filaments may be non-crimped fibers, but are preferably crimped fibers. The degree of crimp of the crimped fibers can be, for example, about 5 to 75, preferably 10 to 50, and more preferably 15 to 50, per 2.54 cm. Uniformly crimped fibers can also be used.

[0022] (Superabsorbent polymer particles) The absorbent body 56 may contain superabsorbent polymer particles in part or in whole. The superabsorbent polymer particles include not only "particles" but also "powder". The superabsorbent polymer particles may be those used in this type of absorbent article as they are. The particle size of the superabsorbent polymer particles is not particularly limited, but it is preferable that when the particles are sieved (shaken for 5 minutes) using a 500 μm standard sieve (JIS Z8801-1:2006) and the particles that fall through the sieve are sieved (shaken for 5 minutes) using a 180 μm standard sieve (JIS Z8801-1:2006), the proportion of particles remaining on the 500 μm standard sieve is 30% by weight or less and the proportion of particles remaining on the 180 μm standard sieve is 60% by weight or more.

[0023] The material of the superabsorbent polymer particles is not particularly limited, but preferably has a water absorption of 40 g / g or more. The superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based materials, and may be starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose, and acrylic acid (salt) polymers. The shape of the superabsorbent polymer particles is preferably a powder-like shape that is commonly used, but other shapes may also be used.

[0024] The highly absorbent polymer particles preferably have a water absorption speed of 70 seconds or less, particularly 40 seconds or less. If the water absorption speed is too slow, the liquid supplied into the absorbent body 56 tends to flow back out of the absorbent body 56, which is called backflow.

[0025] Moreover, the highly absorbent polymer particles preferably have a gel strength of at least 1000 Pa. This makes it possible to effectively prevent the sticky feeling after absorbing liquid, even when the absorbent body 56 is bulky.

[0026] The basis weight of the highly absorbent polymer particles can be appropriately determined according to the absorption amount required for the application of the absorbent body 56. Therefore, although it cannot be generally stated, it is generally in the range of 50 to 350 g / m 2 The polymer weight is 50 g / m 2 If it is less than 350g / m, it will be difficult to ensure sufficient absorption. 2 If the amount exceeds this range, not only will the effect become saturated, but the excess of the highly absorbent polymer particles will give rise to an uncomfortable gritty feeling.

[0027] (packaging sheet) In order to prevent the superabsorbent polymer particles from escaping or to improve the shape retention of the absorbent body 56, the absorbent body 56 can be incorporated as an absorbent element 50 wrapped in a wrapping sheet 58. As the wrapping sheet 58, tissue paper, particularly crepe paper, nonwoven fabric, polylaminated nonwoven fabric, a sheet with small holes, etc. can be used. However, it is preferable that the sheet is one from which the superabsorbent polymer particles do not escape. When using nonwoven fabric instead of crepe paper, hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and the material that can be used is polypropylene, polyethylene / polypropylene, etc. The fiber basis weight is 5 to 40 g / m 2 , especially 10 to 30 g / m 2 It is preferable that the following be used.

[0028] As shown in FIG. 3, this packaging sheet 58 may be constructed so that a single sheet wraps the entire absorbent body 56, or it may be constructed so that multiple sheets, such as two sheets above and below, wrap the entire absorbent body 56. The packaging sheet 58 may also be omitted.

[0029] (Top sheet) The top sheet 30 is liquid permeable, and may be, for example, a nonwoven fabric with or without holes, a porous plastic sheet, or the like. The raw fiber of the nonwoven fabric is not particularly limited. Examples of the raw fiber include synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters, and polyamides, regenerated fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of these. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as the spunlace method, the spunbond method, the thermal bond method, the meltblown method, the needle punch method, the air-through method, and the point bond method. For example, if flexibility and drape are required, the spunlace method is a preferred processing method, and if bulkiness and softness are required, the thermal bond method is a preferred processing method.

[0030] The top sheet 30 extends from the front end to the rear end of the product in the front-to-rear direction, and extends laterally than the absorbent body 56 in the width direction WD; however, appropriate modifications can be made as necessary, such as making the width of the top sheet 30 shorter than the overall width of the absorbent body 56, for example, when the starting point of the rising gathers 60 described below is located closer to the widthwise center than the side edges of the absorbent body 56.

[0031] (middle seat) In order to quickly transfer liquid that has permeated the top sheet 30 to the absorbent body, an intermediate sheet (also called a "second sheet") 40 that has a faster liquid permeability rate than the top sheet 30 can be provided. This intermediate sheet 40 is intended to quickly transfer liquid to the absorbent body, improve the absorption performance of the absorbent body, and prevent the "backflow" phenomenon of absorbed liquid from the absorbent body. The intermediate sheet 40 can also be omitted.

[0032] Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, mixed sheet of pulp and rayon, point-bond nonwoven fabric, and crepe paper. Air-through nonwoven fabric is particularly preferred because of its bulkiness. For the air-through nonwoven fabric, it is preferable to use composite fibers with a core-sheath structure, and in this case, the resin used for the core may be polypropylene (PP), but is preferably polyester (PET) with high rigidity. The basis weight is 17 to 80 g / m 2 is preferable, and 25 to 60 g / m 2 The thickness of the raw fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use eccentric fibers, hollow fibers, or eccentric and hollow fibers as all or part of the raw fiber mixture in order to make the nonwoven fabric bulky.

[0033] In the illustrated example, the intermediate sheet 40 is shorter than the width of the absorbent body 56 and is disposed in the center, but it may be provided over the entire width. The intermediate sheet 40 may be provided over the entire length of the diaper, or may be provided only in the middle portion including the excretion position as in the illustrated example.

[0034] (Liquid-impermeable sheet) The liquid-impermeable sheet 11 is not particularly limited, but is preferably moisture-permeable. For example, a microporous sheet obtained by kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching the sheet in a uniaxial or biaxial direction can be suitably used as the liquid-impermeable sheet 11. In addition, a sheet having a nonwoven fabric as a base material and enhanced waterproofness can also be used as the liquid-impermeable sheet 11.

[0035] It is desirable that the liquid-impermeable sheet 11 extend over the same or a wider area than the absorbent 56 in the front-rear direction LD and the width direction WD, but if necessary, for example when other water-blocking means are present, it may be structured so as not to cover the ends of the absorbent 56 in the front-rear direction LD and the width direction WD.

[0036] (Exterior nonwoven fabric) The exterior nonwoven fabric 12 covers the entire back side of the liquid-impermeable sheet 11, and gives the outer surface of the product a cloth-like appearance. The exterior nonwoven fabric 12 is not particularly limited, and examples of the material fiber include synthetic fibers such as olefins, polyesters, and polyamides, such as polyethylene and polypropylene, as well as regenerated fibers such as rayon and cupra, and natural fibers such as cotton, and the processing method can be spunlace, spunbond, thermal bond, air-through, needle punch, etc. However, long fiber nonwoven fabrics such as spunbond nonwoven fabrics, SMS nonwoven fabrics, and SMMS nonwoven fabrics are preferred in terms of achieving both softness and strength. The nonwoven fabric can be used in a single layer or in a stack of multiple layers. In the latter case, it is preferable to bond the nonwoven fabrics together with a hot melt adhesive or the like. When using a nonwoven fabric, the fiber basis weight is 10 to 50 g / m 2 , especially 15 to 30 g / m 2 It is preferable that the following be used.

[0037] (Rising Gathers) In order to prevent excrement from moving laterally along the top sheet 30 and to prevent so-called lateral leakage, it is preferable that rising gathers 60 that rise towards the wearer's skin are provided on both sides in the width direction WD of the front surface. Of course, the rising gathers 60 can be omitted.

[0038] When the rising gathers 60 are used, the structure is not particularly limited, and any known structure can be used. The rising gathers 60 in the illustrated example are composed of a gather sheet 62 that is substantially continuous in the width direction WD, and an elongated gather elastic member 63 that is fixed to the gather sheet 62 in a stretched state along the front-rear direction LD. A water-repellent nonwoven fabric can be used as the gather sheet 62, and rubber thread or the like can be used as the gather elastic member 63. The elastic members can be provided in multiples as shown in Figs. 1 and 2, or one each.

[0039] The inner surface of the gathered sheet 62 has a joining start point in the width direction WD on the side of the top sheet 30, and the portion extending from this joining start point to the outer side in the width direction is joined by a hot melt adhesive or the like to the inner surface of each side flap portion SF, that is, in the illustrated example, to the side of the liquid-impermeable sheet 11 and the side of the exterior nonwoven fabric 12 located on the outer side in the width direction.

[0040] Around the legs, the widthwise inward portion of the joining start point of the rising gathers 60 is fixed onto the top sheet 30 at both ends in the front-to-back direction of the product, but the portion therebetween is an unfixed free portion, which stands up due to the contractile force of the elastic member 63 and comes into close contact with the surface of the body.

[0041] (End flap section, side flap section) The illustrated tape-type disposable diaper has a pair of end flap portions EF that do not have an absorbent body 56 and extend to the front and rear sides of the absorbent body 56, respectively, and a pair of side flap portions SF that do not have an absorbent body 56 and extend laterally beyond both side edges of the absorbent body 56. The side flap portions SF may be made of a material (such as the exterior nonwoven fabric 12) that is continuous with the portion that has the absorbent body 56, as in the illustrated example, or may be formed by attaching other materials.

[0042] (Flat gather) A side elastic member 64 made of an elongated elastic member such as rubber thread is fixed to each side flap portion SF in a stretched state along the front-to-rear direction LD, whereby the leg portions of each side flap portion SF are configured as flat gathers. As shown in the illustrated example, the leg elastic member 64 is provided between the gathered sheet 62 and the liquid-impermeable sheet 11 on the widthwise outer side near the joining start end of the joining portion of the gathered sheet 62, and can also be provided between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 12 in the side flap portion SF. A plurality of leg elastic members 64 can be provided on each side as shown in the illustrated example, or only one can be provided on each side.

[0043] The plane gathers are the portions on which the contractile force of the side elastic members 64 acts (portions on which the side elastic members 64 are illustrated in the drawings). Thus, in addition to a configuration in which the side elastic members 64 are present only in the areas of the plane gathers, the configuration also includes a configuration in which the side elastic members 64 are present on the front side, rear side, or both sides of the plane gathers, but the side elastic members are cut into small pieces at one or multiple locations outside the areas of the plane gathers, or are not fixed to the sheets sandwiching the side elastic members 64, or both, so that the contractile force of the side elastic members 64 acts only on the areas of the plane gathers without acting on areas other than the plane gathers (effectively equivalent to no elastic members being provided).

[0044] (Connecting tape) The side flap portions SF of the dorsal portion B are each provided with a connecting tape 13 that is detachably connected to the outer surface of the abdominal portion F. When putting on the disposable diaper 10, the connecting tape 13 is wrapped around the outer surface of the abdominal portion F from both sides of the waist, and the connecting portions 13A of the connecting tape 13 are connected to appropriate positions on the outer surface of the abdominal portion F.

[0045] The structure of the connecting tape 13 is not particularly limited, but in the illustrated example, it has a base end 13C fixed to the side flap portion SF and an extension portion 13B extending outward in the width direction WD from the base end 13C. The extension portion 13B has a sheet base material and a connecting portion 13A provided in the width direction intermediate portion of the sheet base material, which connects to the ventral outer surface, and the tip side of the connecting portion 13A is a gripping portion 13D.

[0046] The widthwise intermediate portion N of the connecting tape 13 refers to the range between a point SS 5 mm away from the tip end and a point UU 5 mm away from the base end, based on the widthwise intermediate point TT of the connecting portion 13A. In other words, the widthwise intermediate portion N of the connecting portion 13A is the portion between SS and UU, and the length in the width direction WD is 1 cm.

[0047] In the embodiment of FIG. 7(a), the length of the connecting tape 13 in the front-rear direction LD is gradually narrowed in a stepped manner from the base end portion 13C to the tip end side. The stepped shape means that the front-rear direction edge of the connecting tape 13 is narrowed while drawing a plurality of steps like a staircase, not narrowed in a gentle curve as in Prior Art Document 2. In the embodiment of FIG. 7(a), the number of steps of the extension portion 13C is three, but it may be two or four or more. The difference in the length of adjacent steps in the front-rear direction is preferably about 5 mm to 10 mm.

[0048] The length Q of the connecting tape 13 in the front-rear direction LD is the same in the widthwise intermediate portion N of the connecting tape 13. The length Q of the connecting tape 13 in the front-rear direction LD of the widthwise intermediate portion N of the connecting tape 13 is preferably 15 mm to 45 mm, more preferably 20 mm to 40 mm, and even more preferably 25 mm to 37.5 mm. The length Q of the connecting tape 13 in the front-rear direction LD of the connecting tape 13 in the widthwise intermediate portion N is preferably 55% to 95% of the length P of the base portion 13E in the front-rear direction LD of the extending portion 13B (the length of the front-rear direction LD of the portion where the outer edge of the side flap portion SF in the widthwise direction WD and the connecting tape 13 overlap. The same applies below.) of the connecting tape 13. The length Q of the connecting tape 13 in the front-rear direction LD of the widthwise intermediate portion N of the connecting tape 13 is preferably half the length O of the base end portion in the front-rear direction. The present invention is not limited to this embodiment, and may be, for example, an embodiment in which the length of the tip portion SS of the widthwise intermediate portion N is shorter than the length of the base end portion UU. However, if the length of the tip portion SS is too short compared to the length of the base end portion UU, the peel strength will be weakened as in Patent Document 1. Therefore, when the length of the base end portion UU is 100%, it is preferable to set the length of the tip portion SS to about 90% to 100%. Specifically, when the length of the base end portion UU is 25 mm to 26 mm, it is preferable to set the length of the tip portion SS to 24 to 25 mm, and when the length of the base end portion UU is 37.5 mm to 39 mm, it is preferable to set the length of the tip portion SS to 36 to 37.5 mm. In order to prevent the peel strength from decreasing to the extent that consumers become uneasy, it is preferable to set the difference in length between the base end portion UU and the tip portion SS (length difference) to within 2 mm.

[0049] The length P in the front-rear direction LD of the root portion 13E of the extension portion 13B is preferably about 63% to 70% of the length O in the front-rear direction of the base end portion. By making the length P in the front-rear direction LD of the root portion 13E of the extension portion 13B 63% or more, the length of the root portion 13E becomes sufficiently long, and it is possible to prevent the occurrence of twisting of the nonwoven fabric that is likely to occur in the side flap portion SF when worn. In addition, by making the length P in the front-rear direction LD of the root portion 13E of the extension portion 13B 70% or less, as shown in FIG. 8, when the left and right connecting tapes 13, 13 are manufactured to have the same shape (mirror image), it is possible to ensure that the front-rear length of the gripping portion 13D is at least about 30% of the front-rear direction length O of the base end portion 13C, and therefore it is possible to prevent the ease of gripping the connecting tape 13 from being deteriorated. Specifically, the length P in the front-rear direction LD of the root portion 13E of the extending portion 13B is preferably 30 mm to 48 mm, and the length O in the front-rear direction of the base end portion 13C is preferably 50 mm to 75 mm. The difference (difference in length) between the length P in the front-rear direction LD of the root portion 13E of the extending portion 13B and the length O in the front-rear direction of the base end portion 13C is preferably within 20 mm. In general, the length in the front-rear direction of the gripping portion 13D is preferably about 50% to 70% of the length Q in the front-rear direction LD of the widthwise intermediate portion N of the connecting tape 13. Specifically, the length in the front-rear direction of the gripping portion 13D is preferably about 10 mm to 27 mm.

[0050] By setting the length P in the front-rear direction LD of the base portion 13E of the extending portion 13B and the length Q in the front-rear direction LD of the widthwise intermediate portion N of the connecting tape 13 to the above lengths, it is possible to increase the thickness of the extending portion 13B from the base portion 13E of the extending portion 13B to the widthwise intermediate portion N of the connecting tape 13. This makes it possible to prevent twisting from occurring between the base portion 13E of the extending portion 13B and the widthwise intermediate portion N of the connecting tape 13.

[0051] In the embodiment of FIG. 7(a), the length of the base end 13C in the width direction WD is preferably 15 mm to 25 mm. BaseThe length of the portion 13E in the width direction WD is preferably 10 mm to 15 mm. Furthermore, the length of the connecting portion 13A in the width direction WD is preferably 18 mm to 24 mm, and the length of the knob portion 13D in the width direction WD is preferably 10 mm to 15 mm.

[0052] In the embodiment of FIG. 7(a), six curved portions R1 to R6 are formed on one side of the connecting tape 13 in the front-rear direction from the base end side to the tip end side. R1, R3, and R5 are concave curved lines toward the center side of the connecting tape 13 in the front-rear direction, and R2, R4, and R6 are convex curved lines toward the outside of the connecting tape 13 in the front-rear direction. The extending portion 13B extends in three stages, from R1 to R2, from R3 to R4, and from R5 to R6, and is characterized in that the second stage R3 to R4 is an almost flat section. By using many curved sections as the shape of the connecting tape 13, the connecting tape 13 becomes softer, more comfortable to the touch, and less likely to peel off, compared to when the corresponding parts are made acute-angled. In addition, by making the second stage an almost flat section, the connecting force (also called adhesive force) of the connecting portion 13A to the ventral outer surface can be increased compared to the prior example shown in FIG. 7(b).

[0053] 7(a) is modified to be more suitable, the length of the connecting part 13A in the width direction WD is made shorter than the length of R3-R4, and the connecting part 13A is preferably placed between R3-R4. In such a configuration, when the wearer's foot comes into contact with the base part 13E of the connecting tape, i.e., the peripheral part M of R2, the convex part of R2 is easily folded back because the connecting part 13A is not present in the peripheral part M. This has the advantage that the connecting part 13A is less likely to come into contact with the foot.

[0054] As described above, if the length in the front-rear direction from the tip end SS to the base end UU in the widthwise intermediate portion N of the connecting tape 13 is constant and the same, the two straight lines connecting the tip ends S, S and the base ends U, U will be straight and parallel. If such a connecting tape 13 is attached in parallel to the front target tape provided on the outer surface of the ventral side, there is an advantage that the tape is less likely to slip even if the wearer (especially the baby) moves.

[0055] The connecting portion 13A may be provided with a hook material (male material) of a mechanical fastener (hook-and-loop fastener) or with an adhesive layer. The hook material has many engaging protrusions on its connecting surface, and the shapes of the engaging protrusions include (A) L-shape, (B) J-shape, (C) mushroom-shape, (D) T-shape, and (E) double J-shape (a shape in which two J-shapes are joined back to back), and any shape may be used.

[0056] The sheet base material forming the portion from the base end 13C to the extension 13B may be a nonwoven fabric, a plastic film, a polylaminated nonwoven fabric, paper, or a composite material thereof. 2 A spunbond nonwoven fabric, an air-through nonwoven fabric, or a spunlace nonwoven fabric having a thickness of 1 mm or less is preferred.

[0057] Moreover, the shape of the connecting tapes 13 provided on the left and right sides of the side flap portion SF is preferably such that when the connecting tapes 13 are rotated 180 degrees and arranged alternately, the side edges of the connecting tapes 13 match each other, i.e., they form a mirror image, as shown in Fig. 8. With such a shape, no cutting pieces are produced when the connecting tapes 13 are manufactured, making it easier to keep the manufacturing site clean and improving manufacturing efficiency.

[0058] (Target sheet) It is preferable to provide a target portion at the connection portion of the connecting tape 13 in the abdominal part F. The target portion can be provided by attaching a target sheet 20 for facilitating connection to the outer surface of the abdominal part F, as in the illustrated example. When the connecting portion 13A is made of a hook material, the target sheet 20 can be provided on the surface of a sheet base material made of a plastic film or nonwoven fabric, on which a large number of loop threads are provided so that the engaging protrusions of the hook material can be entangled. In the case of an adhesive layer, the target sheet 20 can be provided on the surface of a sheet base material made of a smooth plastic film with high adhesiveness, on which a release treatment has been applied. In addition, when the connecting portion of the connecting tape 13 in the abdominal part F is made of a nonwoven fabric, for example, when the outer nonwoven fabric 12 is provided as in the illustrated example, the target sheet 20 can be omitted, and the hook material can be entangled with the fibers of the outer nonwoven fabric 12 for connection. In this case, the target sheet 20 as a marker can be provided between the outer nonwoven fabric 12 and the liquid-impermeable sheet 11, and a marker can be printed on the outer surface of the outer nonwoven fabric 12 or the liquid-impermeable sheet 11.

[0059] (Wing part) As shown in Figs. 1 and 2, this tape-type disposable diaper has a crotch portion M extending from the middle of the ventral portion F in the front-to-rear direction LD to the middle of the back portion B in the front-to-rear direction LD. The ventral portion F and the back portion B have wing portions WP extending outward in the width direction WD beyond the crotch portion M. The lower edge 70 of the wing portion of the ventral portion F extends from the front end of the side edge of the crotch portion M toward the front so as to be positioned obliquely outward, and the lower edge 75 of the wing portion of the back portion B extends from the rear end of the side edge of the crotch portion M toward the rear so as to be positioned obliquely outward. In the illustrated example, the side edges of the wing portions WP are straight, but are not limited to this and other known shapes may be adopted. The dimension of the crotch portion M in the front-to-rear direction LD can be determined as appropriate, but the minimum width M of the crotch portion M is preferably 10 mm or more. X In the case of use for infants, the dimension M in the front-rear direction LD of the crotch area M can be set to about 1.2 to 1.4 times. Y is about 10 to 30 cm.

[0060] (Experimental Example) 7, (a) is the tape according to the present invention, and (b) is the tape described in Patent Document 1. Using these two types of tapes, a peel strength test was carried out as described below.

[0061] First, the tape-type disposable diapers equipped with the connecting tapes (a) and (b) were prepared, and only the front target portion was cut and removed from each diaper. Then, each diaper was attached to the mounting table of a tensile tester (manufactured by Shimadzu Corporation, model number AG-X500N). Next, the connecting tape was attached to the outer surface of the front body in the same manner as when the diaper was worn, and a load was applied to the connecting tape. This load was applied by moving a 2 kg roller back and forth once over the connecting tape. After that, the connecting tape was peeled off in a 90-degree direction by the tensile tester at a speed of 300 mm / min.

[0062] The experimental results are shown in Table 1.

[0063] [Table 1]

[0064] It can be seen that the peel strength of the widthwise intermediate portion of the connecting tape is higher in the shape of FIG. 7(a) than in the shape of FIG. 7(b). In particular, in FIG. 7(a), the peel strength of the widthwise intermediate portion of the connecting tape is 179 gf, and the maximum convex point is 301 gf, so the difference is 122 gf. In contrast, in FIG. 7(b), the peel strength of the widthwise intermediate portion of the connecting tape is 124 gf, and the maximum convex point is 283 gf, so the difference is 159 gf. In other words, the difference is smaller in FIG. 7(a), so the wearer can feel that the connecting tape is firmly fixed when peeling it off. In addition, in the shape of FIG. 7(b), the peel strength of the widthwise intermediate portion of the connecting tape is a low value of 124 gf, so there is a disadvantage that it peels off easily.

[0065] <Explanation of terms used in the specification> As used herein, the following terms have the following meanings unless otherwise specified in the specification. The "front-rear direction" refers to the direction indicated by the symbol LD in the drawing (longitudinal direction), and the "width direction" refers to the direction indicated by the symbol WD in the drawing (left-right direction), with the front-rear direction and the width direction being perpendicular to each other.

[0066] "Curved" does not include straight lines.

[0067] "Unfolded state" means a flat, unfolded state without contraction or sagging.

[0068] "Elongation rate" refers to the value when the natural length is 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2 times.

[0069] - "Basis weight" is measured as follows. After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%) until it reaches a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight in an environment at a temperature of 100°C. Note that pre-drying is not necessary for fibers with an official moisture regain of 0.0%. From the test piece that has reached a constant weight, a sample template (100mm x 100mm) is used to cut out a sample measuring 100mm x 100mm. The weight of the sample is measured and multiplied by 100 to calculate the weight per square meter, which is the basis weight.

[0070] "Thickness" is measured using an automatic thickness measuring device (KES-G5 handy compression tester) with a load of 0.098N / cm 2 , and pressure area: 2cm 2 The measurement is performed automatically under the following conditions.

[0071] "Water absorption" is measured in accordance with JIS K7223-1996 "Test method for water absorption of superabsorbent polymers."

[0072] "Water absorption rate" is the "time to the end point" when 2g of superabsorbent polymer and 50g of physiological saline are used and the JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers" is performed.

[0073] If no specification is given regarding the environmental conditions for a test or measurement, the test or measurement shall be carried out in a test room or equipment under standard conditions (the test location shall be a temperature of 23±1°C and a relative humidity of 50±2%).

[0074] *Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not in the natural length state. [Industrial Applicability]

[0075] The present invention is applicable to tape-type disposable diapers such as those in the above examples. [Explanation of symbols]

[0076] 11...liquid-impermeable sheet, 12...exterior nonwoven fabric, 13...connecting tape, 13A...connecting portion, 13B...extending portion, 13C...base end portion, 13D...grip portion, 13E...root portion, 20...target sheet, 30...top sheet, 40...middle sheet, 50...absorbent element, 56...absorbent body, 58...packaging sheet, 60...rise gathers, 62...gathered sheet, 64...side elastic member, B...back portion, F...ventral portion, LD...front-rear direction, M...crotch portion, SF...side flap portion, WD...width direction, WP...wing portion

Claims

1. A crotch portion having both side edges extending from a middle of the ventral portion in the front-to-rear direction to a middle of the dorsal portion in the front-to-rear direction, and a ventral portion extending forward from a middle of the ventral portion in the front-to-rear direction, and a crotch portion having both side edges extending from a middle of the ventral portion in the front-to-rear direction to a middle of the dorsal portion in the front-to-rear direction, An absorbent body incorporated in an area including the crotch area; Wing portions extending outward in a width direction beyond the crotch portion on the ventral portion and the dorsal portion; The back portion has connecting tapes on both sides thereof for detachably connecting to the ventral portion. In tape-type disposable diapers, The connecting tape has a base end portion fixed to the wing portion and an extension portion extending outward in a width direction from the base end portion, The shape of the extension portion of the connecting tape is such that the length in the front-rear direction narrows in a stepped manner from the base end side to the tip end side, The length of the extension portion in the front-rear direction at the widthwise intermediate portion is 15 mm to 45 mm, The length in the front-rear direction of the widthwise intermediate portion of the extension portion is the same at any point in the widthwise direction, or the length varies depending on any point in the widthwise direction, and the difference between the longest part and the shortest part is within a range of 2.0 mm; A connecting portion for fixing the connecting tape to an outer surface of the abdominal portion is provided at least in a width direction intermediate portion of the extending portion of the connecting tape, The connecting portion is not provided at a base portion of the extending portion of the connecting tape that is closer to the base end of the extending portion in the width direction than a middle portion of the extending portion in the width direction, The width direction intermediate portion of the extending portion of the connecting tape is a range between a point 5 mm away from the tip end side and a point 5 mm away from the base end side based on the width direction intermediate point of the connecting portion, The connecting tape has a protruding portion at the base portion that faces outward in the front-rear direction, The connecting portion is not provided on the protruding portion, The connecting portion is a hook member of a mechanical fastener, The connecting portion is not provided on the base end side from the convex portion. A tape-type disposable diaper characterized by:

2. 2. The tape-type disposable diaper according to claim 1, wherein a gripping portion for gripping the connecting tape is provided on the widthwise tip side of the extension portion of the connecting tape rather than on the widthwise middle portion of the extension portion, the gripping portion being a part of the extension portion, and the connecting portion is not provided on the gripping portion.

3. Both end edges of the connecting tape in the front-rear direction have a shape in which concave curves and convex curves are alternately arranged from the base end side to the tip end side, 3. The tape-type disposable diaper according to claim 1, wherein the connecting portion is disposed between a concave curve and a convex curve provided at both ends of the widthwise middle portion of the extending portion of the connecting tape, and is not disposed at any location other than the widthwise middle portion of the extending portion of the connecting tape.

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