BR122021000255B1 - DISPOSABLE DIAPER - Google Patents

Abstract

The present invention aims to provide an improved disposable diaper to ensure a desired adaptation of the diaper to the user's body, particularly in the region defined between the buttocks and legs. The disposable diaper comprises an abdominal sheet member (2) and a dorsal sheet member (3) extending parallel to each other in a transverse x direction and a hook sheet member extending in the longitudinal y direction and joined to the back sheet member. abdominal leaf (2) and the dorsal leaf member (3) wherein the crotch leaf member (4) has a transverse dimension smaller than those of the abdominal (2) and dorsal leaf members, characterized by the abdominal leaf member (2) (2) and the backsheet member (3) are provided with waist-surrounding elastic members 6 connected thereto under tension in the transverse direction, opposite side edges extending in the longitudinal direction on both sides of the crotchsheet member ( 4) become parallel to each other when the disposable diaper is laid flat and an apparent width of the crotch sheet member (4) measured in the transverse direction after the elastic surrounding the waist members have been left contracted and therefore the member of the crotch sheet (4) was allowed to shrink is greater on the edge line b2 with the dorsal sheet member (3) than on the edge line b1 with the abdominal sheet member (2), referring to figure 3.

Description

[0001] The present invention relates to a disposable diaper.

[0002] As one of several types of disposable diaper, a diaper comprising three rectangular sheets joined together in an I-shape (hereinafter referred to as a three-piece diaper) is well known. The three-piece diaper advantageously reduces the cost of production particularly in view of no fur waste being generated during the manufacturing process of such a diaper. However, it is difficult for diapers of this type to cover the wearer's crotch region and buttocks in an appropriate manner since the rectangular sheet is partitioned to cover the wearer's crotch region. More specifically, the sheet having a waist sized to cover the wearer's crotch region in an appropriate manner would have to be too small to cover the wearer's buttocks completely taking up a large uncomfortable bulk in the wearer's crotch region.

[0003] In view of said problem, PATENT DOCUMENT 1 discloses a pant-like diaper comprising a front waist panel and a crotch panel provided therebetween front and rear waist panels where these front and rear waist panels are joined together. the other along opposite side edges of the front waist panel and opposite side edges of the rear waist panel being joined to form a waist opening and a pair of leg openings characterized in that the width of the back waist panel strap is sized to be wider than the front waist panel strap width. As can be seen from Figure 1 of PATENT DOCUMENT 1, the waist opening is defined by the respective higher edges (distal edges) of the front waist panel and the rear waist panel and the even leg openings being defined by the respective higher edges. lower (proximal edges) of the front waist panel and rear waist panel cooperating with opposite side edges of the crotch panel, respectively.

PURPOSE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] < Problem to be solved by the Second Aspect > Certainly the diaper disclosed in PATENT DOCUMENT 1 is able to cover the wearer's buttocks over a sufficient extent since the width of the same strap is dimensioned to be greater. However, said differential dimension will inevitably result in an inconvenience as the rear waist panel is not partially joined to the front waist panel. With the diaper worn on the wearer's body, the back waist panel section will remain unjoined to the front waist panel and may often be out of contact with the wearer's buttocks and may not ensure the desired convenience of this section to a defined region between the buttocks and legs. Furthermore, the three rectangular sheet U-shaped diaper necessarily forms a pair of leg openings on either side of the wearer's body so as to be parallel to each other. It should be noted here that a mobile variation of the human legs will mainly extend towards the trunk of the body and therefore the leg openings should preferably open slightly forward.

[0005] In view of the problem reported above, it is a main objective of the present invention to provide an improved three-piece diaper to ensure a desired comfort of the diaper on the wearer's body particularly in the defined region between the buttocks and the legs.

[0006] The objective set out above will be achieved, according to the present invention, by an improvement in the disposable diaper (hereinafter referred to only as diaper) symmetrical above an imaginary center line thereof and comprising a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, a member of the abdominal sheet and a member of the back sheet extending parallel to each other in the transverse direction, and a member of the crotch region extending in the longitudinal direction and joined to the abdominal sheet member and the back sheet member to connecting these members of the abdominal and dorsal sheets to each other where the member of the crotch region has a lower transverse dimension than that of the members of the abdominal and dorsal sheets.

[0007] The improvement according to the present invention is characterized in that the abdominal sheet member and the back sheet member are provided with elastic members surrounding the waist attached thereto under tension in the transverse direction, in a region of the abdominal sheet member. wherein the elastic members surrounding the waist are present and the crotch sheet member are overlapping one another, opposite side edges extending in the longitudinal direction on both sides of the crotch sheet member being parallel to each other when the disposable diaper is flatly developed, and an apparent width of the crotch sheet member as measured in the transverse direction after the elastic members encircling the waist have been left contracted and thus the crotch sheet member has been allowed to retract together with the abdominal sheet member and the waist member dorsal leaf being larger in a row from the edge with the dorsal leaf member than in a row from the edge with the member of the abdominal leaf.

[0008] The expression “the disposable diaper is flatly developed” used here means that the abdominal sheet member, the back sheet member and the crotch member are developed and seated against the elastic force of the elastic members encircling the waist or other elastic members. . The expression "letting the various limbs contract" used herein means that the elastic members encircling the waist attached in tension to the diaper are freely contracted in the absence of any external force exerted on the diaper until equilibrium with a drag on the materials constituting the members of the abdominal sheets. and dorsal are achieved.

[0009] According to a preferred embodiment, the crotch sheet member is provided along opposite side edges of the crotch sheet member with the elastic members attached thereto under tension and, in addition, provided with the body fluid absorbent structure spaced within the opposite side edges of the crotch sheet member to be symmetrical above the longitudinal centerline, the body fluid absorbent structure having a pair of longitudinal sides extending parallel to the opposite side edges of the crotch sheet member, the longitudinal sides opposite sides curving internally to the body fluid absorbent structure to form symmetrically curved segments above the longitudinal centerline, and the curved segments resting on the side of the abdominal sheet member as viewed in the longitudinal direction.

[00010] According to another preferred embodiment, the elastic members encircling the waist exhibit, along segments thereof extending through the body fluid absorbent structure on the side of the abdominal sheet member, a greater elastic effort on the side of the abdominal sheet member. than on the side of the backsheet member in the flat developed disposable diaper. In accordance with yet another preferred embodiment, the abdominal sheet member and the back sheet member are provided with the elasticized waist-circling members tensioned thereto so that the elasticized waist-circling members extend through the fluid-absorbing structure. body on the side of the abdominal sheet member being matched at intervals close to those intervals of the elastic members encircling the waist which extend through the body fluid absorbent structure on the side of the back sheet member. In yet another preferred embodiment, the elastic members encircling the waist extend across the backsheet member exhibiting in the vicinity of the edge line between the backsheet member and the crotch sheet member an elasticity lower than that exhibited by such members. elastic bands around the waist in the remaining region.

[00011] According to another preferred embodiment, the disposable diaper has been formed into pants by joining opposite side edges extending in the longitudinal direction on both sides of the abdominal sheet member to opposite side edges extending in the longitudinal direction in both sides of the backsheet member so that the abdominal and backsheet members are annular shaped unit to each other to define a waist opening while the backsheet and backsheet members are also annularly joined cooperating with the backsheet member. crotch leaf joined to these members of the abdominal and dorsal leaves to define a pair of leg openings.

[00012] In the diaper according to the present invention, the apparent transverse dimension of the crotch sheet member as measured after the elastic members encircling the waist have been contracted and thereby the crotch sheet member retracted together with the abdomen sheet member and the dorsal leaf member being larger along the edge line with the dorsal leaf member than along the edge line with the abdomen leaf member being sufficiently larger on the dorsal side than the abdomen side to ensure that the user's buttocks can be safely covered with this dorsal section.

[00013] The apparent transverse dimension of the crotch sheet member is relatively small and therefore it will not be understood that the crotch sheet member may become bulky in the wearer's crotch region and the wearer experiencing a feeling of discomfort when donning the diaper. In addition, the apparent transverse dimension of the crotch leaf member gradually decreases from the dorsal side towards the abdominal side. This feature leads to an advantageous effect. Specifically, a pair of leg openings is defined by the cooperation of the crotch sheet member with the annular junction of the dorsal and abdominal members being angled to open properly in front of the diaper. These features allow the present invention to provide the three-piece disposable diaper with improved convenience of the diaper to the wearer's body primarily in the region extending from the wearer's buttocks towards the wearer's legs.

[00014] BRIEF DESCRIPTION OF THE DRAWINGS - Figure 1 is a plan view showing the diaper according to the first embodiment of the invention as developed planarly; - Figure 2 is a sectional view taken along the line IX-IX of Figure 1; - Figure 3 is a plan view showing the diaper with the elastic members surrounding the waist left contracted; - Figure 4 is a perspective view showing the diaper as formed into pants; - Figure 5 schematically shows the diaper having been formed into pants as seen from the abdominal side; - Figure 6 schematically shows the diaper having been formed into pants as seen from the dorsal side; - Figure 7 is a plan view showing the diaper according to the second configuration of the invention as developed planarly; - Figure 8 is a plan view showing the diaper with the elastic members surrounding the waist left contracted; - Figure 9 schematically shows the diaper having been formed in pants on the abdominal side; - Figure 10 schematically shows the diaper having been formed in pants on the dorsal side;

[00015] <Numeric references> 1 disposable diaper 2 abdominal sheet member 3 back sheet member 4 crotch region member 5 body fluid absorbent structure 6 elastic members encircling the waist 7 waist opening 8 leg openings 21 opposite side edges of the abdominal region 22 opposite side edges of the dorsal region 41 opposite side edges of the crotch region 42 elastic limbs for the crotch region 51 straight side edge segments 52 curved side edge segments

[00016] Details of the diaper 1 according to the present invention will be described with reference to Figures 1 to 3. Figure 1 is a plan view showing the diaper in accordance with the first embodiment of the invention as developed planarly, Figure 2 is a sectional view taken along a line ll-ll of Figure 1 and Figure 3 is a plan view showing the diaper with elastic members encircling the waist released from a stretched state as shown in Figure 1.

[00017] Figure 1 illustrates the diaper 1 as a side view of it, facing the user's skin. The diaper 1 comprises a rectangular abdominal sheet member 2 extending in a transverse direction indicated by an arrow X, a rectangular back sheet member 3 spaced from the abdominal sheet 2 and extending parallel to the abdominal sheet member 2 in the transverse direction and a rectangular crotch sheet member 4 extending in a longitudinal direction indicated by an arrow Y and having longitudinally opposite end parts joined to the abdominal sheet member 2 and the back sheet member 3, respectively, at the medial parts of these abdominal and back sheet members respectively 2, 3. The crotch sheet member 4 has a smaller transverse dimension than that of the abdominal sheet member 2, as well as that of the back sheet member 3 including a body fluid absorbent structure 5. The diaper 1 has an I-shape that is symmetrical about a longitudinal centerline M and the body fluid absorbent structure 5 is also symmetrical about the long centerline itudinal M.

[00018] Each member of the abdominal sheet 2 to the member of the back sheet 3 comprises an air permeable top sheet 11 and a back sheet 12 sandwiched between a plurality of abdominal rubber threads 61 or back rubber threads 61 where these rubber threads 61 and 62 extend under tension in the transverse direction and intermittently affixed to the members of the sheets 2 or 3. The abdominal rubber threads 61 are affixed to the members of the sheets 2 under a higher percentage elongation than an elongation percentage under which the threads rubber bands 62 are attached to the backsheet member 3. Consequently, the abdominal rubber threads 61 exhibit a greater stress than a stress exhibited by the rubber threads 62 associated with the backsheet member when the diaper 1 is flattened. In other words, the rubber threads 61 extending through the body fluid absorbing structure 5 exhibiting a greater effort than the effort exhibited by the rubber threads 62 extending through the body fluid absorbing structure 5. It should be noted that a distance between each pair of abdominal rubber threads 61, as well as a distance between each pair of adjacent rubber threads 62 associated with the backsheet member 3 is constant. The crotch sheet member 4 is placed on the abdominal sheet member 2 and the back sheet member 3 so as to overlap the regions of these two members 2, 3 in which the elastic members encircling the waist 6 are present. With the diaper 1 placed on the wearer's body, the top sheet on the side facing the wearer's skin and the back sheet on the side facing away from the wearer's skin.

[00019] The rectangular crotch sheet member 4 has an area greater than an area of the body fluid absorbent structure 5 included together with the elastic members 42, 42 for the crotch region between a rectangular liquid permeable sheet 43 and a permeable sheet 44. With the diaper 1 placed on the wearer's body, the liquid-permeable sheet 43 on the side facing the wearer's skin and the liquid-impermeable sheet 44 on the side facing away from the wearer's skin. With the diaper 1 flatly developed, the opposing side edges 41, 41 of the crotch sheet 4 extending parallel to each other in the longitudinal direction. All along these opposing side edges 41, 41 of the crotch region, the elastic members 42, 42 are intermittently joined in tension to the crotch sheet member 4. In this first configuration, the rubber threads are used as the elastic members 42, 42 for the crotch. crotch region.

[00020] The body fluid absorbent structure 5 is joined to the crotch sheet member 4 in symmetry about the longitudinal centerline M so that the body fluid absorbent structure 5 is spaced a certain distance from each of the opposing side edges 41 of the crotch region. The body fluid absorbent structure 5 overlaps the abdominal sheet member 2 and the back sheet member 3 so that a longitudinal dimension L1 through which the body fluid absorbent structure 5 overlaps the abdominal sheet member 2 which may be greater than one longitudinal dimension L2 whereby the body fluid absorbent structure 5 overlaps the back sheet member 3. In this way, on the side of the abdominal sheet member 2, a front section of the wearer's crotch region can be covered with the body fluid absorbent structure 5 over a large enough area to absorb urine with high efficiency.

[00021] The body fluid absorbent structure 5 having opposing side edges 51 extending parallel to opposite side edges 41 of the crotch sheet 4. The opposing side edges 51 comprise a pair of opposing segments 53 extending parallel to each other on the side. of the abdominal sheet member 2, a pair of opposing segments 54 extending parallel to each other on the side of the back sheet member 3 and a pair of curved segments 52 extending parallel to each other between the parallel segments 53 on the side of the abdominal sheet member 2 and parallel segments 54 on the side of the back sheet member 3. The segments 52 are curved internally of the body fluid absorbent structure 5 so as to be symmetrical about the longitudinal centerline M of the diaper and the fluid absorbent structure body 5 as a whole presenting a dumbbell-like shape. A transverse distance between the parallel segments 53 on the side of the abdominal sheet member 2, as well as the distance between the parallel segments 54 on the back sheet member 3. A section of the body fluid absorbent structure 5 defined by the parallel segments 54 partially overlapping the dorsal sheet member 3 while a section of body fluid absorbent structure 5 defined by parallel segments 53 completely overlapping abdominal sheet member 2.

[00022] Sections of the liquid-permeable sheet 43 and the liquid-impervious sheet 44 extend outwardly in the transverse direction of the respective curved segments 52 to opposite side edges 41 of the crotch region to form a pair of opposing side flaps 45. These side flaps 45 are provided with elastic members 42 for the crotch region extending along opposite side edges 41. These side flaps 45 do not have the body fluid absorbent structure 5 attached to them and have relatively low rigidity compared to the remaining section of the crotch region. crotch having the body fluid absorbent structure 5 attached thereto. Consequently, these side flaps 45 will be easily deformed in response to stress and contraction from other movements of the elastic members 42 to the crotch region.

[00023] The materials for the respective sheets constituting the diaper may suitably be selected from a group of various types of fibrous non-woven material and/or film made of thermoplastic synthetic resin conventionally used for disposable diapers in consideration of the required properties. As the body fluid absorbent structures 5, body fluid absorbent material well known in the prior art containing tissue paper-wrapped terry pulp (not shown) may be used. The body fluid absorbent structure 5 containing fluffy pulp and thus exhibiting relatively high inflexibility, i.e., relative high resistance to deformation compared to the liquid impermeable sheet 44 and the liquid permeable sheet 43. Like the elastic members 42 for the crotch region and elastic members encircling the waist 6, rubber threads, thermoplastic elastomer, tape-shaped or conical-shaped rubber, or elasticized non-woven material or resin film may be used.

[00024] The bond between the respective sheets, the respective elastic members, and the body fluid absorbent members may be produced using the method well known in the state of the art in the field of disposable diapers, for example, adhesion with heat-melt adhesive or heat seal. The elastic effort of the elastic members surrounding the waist 6, generated when the flattened diaper is developed, may be adjusted by establishing an appropriate percentage of stretch, in which the members surrounding the waist 6 are secured to the diaper. Alternatively, the effort may be adjusted by appropriately varying the material and/or the sectional area of the elastic members encircling the waist 6 on the basis of one and the same percentage of stretch.

[00025] As shown in Figure 2 in a sectional view, the abdominal and dorsal rubber threads 61, 62 overlap the body fluid absorbent structure 5 via the upper sheets 11 of the abdominal and dorsal sheet members 2, 3 and the liquid impermeable sheet 44 of the crotch sheet member 4. These diaper-forming members are bonded to each other by heat-melt adhesive (not shown) so that the body fluid absorbent structure 5 can also contract together with the member. of the abdominal sheet 2, the back sheet member 3 and the crotch sheet member 4 in the transverse direction as the abdominal and back rubber threads 62, 62 contract in the transverse direction (in a direction perpendicular to the surface of Figure 2).

[00026] As will be understood from Figure 3, the front and back sheet members 2, 3 and the crotch sheet member 4 contract in the transverse direction from the flattened state indicated by imaginary lines to the state indicated by solid lines such as yarn abdominal and dorsal rubber 61, 62 left contracted in the transverse direction. At this time, the abdominal sheet member 2 contracts more significantly than the back sheet member 3 and correspondingly the section of the body fluid absorbent structure 5 defined by the parallel segments on the side of the abdominal sheet member 2 contracting more significantly than in the section defined by the parallel segments on the side of the backsheet member 3. This is why the abdominal sheet member 2 involved greater effort than that involved by the abdominal sheet member 3 when the diaper is flatly developed.

[00027] The contraction of the abdominal and dorsal rubber threads 61, 62 motivate the crotch sheet member 4 to also contract in the transverse direction from the rectangular shape indicated by the imaginary line to the trapezoidal shape indicated by a solid line. As a result of contraction in this way, an apparent transverse dimension of the crotch sheet member 4 will be like its width W2 on an edge line with the back sheet member 3 being greater than its width W1 on an edge line like the abdominal sheet member 2. The term "apparent transverse dimension of the crotch sheet member" used herein refers to a distance between the opposite side edges 41 of the crotch sheet member 4 after the transverse dimension W1 and W2 of the crotch sheet member 4 have been reduced under contraction of the rubber threads 61, 62.

[00028] The differential width of the crotch sheet member 4 as the width W2 at the edge line with the back sheet member 3 having been relatively enlarged under contraction of this sheet member 4 allowing the crotch sheet member 4 to cover the buttocks of the wearer over its corresponding greater extent and thereby improve the comfort of the crotch sheet member 4 particularly in the region from the buttocks to the legs. In addition, the differential width of the crotch sheet member 4 so that its width W1 at the edge line with the abdominal sheet member 2 is relatively less under contraction of this crotch sheet member, making it possible to avoid the possibility of the crotch sheet member become bulky and, as a result, as large bulk can deteriorate the feel when wearing the diaper.

[00029] With reference to Figures 4 and 6, the diaper 1 according to this configuration will be described after being formed into pants by joining opposite side edges 21, 21 of the abdominal sheet member 2 extending in the longitudinal direction with the opposite side edges 22, 22 of the backsheet member 3 so that the abdominal sheet member 2 and the backsheet member 3 can be annularly joined together to form the diaper 1 of Figure 4 in pants. Figure 4 is a perspective view showing the diaper 1 formed into pants. Figure 5 schematically shows the pant-formed diaper 1 as seen from the front side particularly with respect to the peripheral edges 81 of the leg openings and Figure 13 schematically shows the pant-formed diaper 1 as seen from the back side.

[00030] As will be apparent from Figure 4, the pant-formed diaper 1 has a waist opening 7 defined by the abdominal sheet member 2 and the back sheet member 3 annularly joined together and a pair of leg openings 8 defined by the member. of the front sheet 2, the back sheet member 3 and the crotch sheet member 4 joined to these two sheet members 2, 3. More specifically, with reference to Figure 1 these leg openings 8 are defined by the proximal edges 13, 14 of the front and back or back sheet members 2, 3 extending in the transverse direction and opposite each other behind the crotch sheet member 4 and the peripheral edges 81 comprising the opposite side edges 41 of the crotch sheet member 4. Specifically to describe , the waist opening 7 is defined by a peripheral edge 71 which is in turn defined by the distal edges 15, 16 extending in the transverse direction parallel to the proximal edges 13, 14 of the m shoulders of the front and back sheets 2, 3 and spaced from each other by a distance greater than a distance by which the proximal edges 13, 14 of the members of the front and back sheets 2, 3.

[00031] As previously described, a pair of easily deformable side flaps 45 extend outwardly from the body fluid absorbent structure 5 and the elastic members 42 for the crotch region are attached under tension to these side flaps 45. These elastic members 42 for the crotch region are tensioned. The crotch region contracts when the crotch sheet member 4 is curved with the body fluid absorbent structure 5 internally to form the pant diaper 1. After that, the side edges elevate themselves to the body fluid absorbent structure 5 between the abdominal sheet member 2 and the back sheet member 3, as will be seen in Figure 4. The side flaps rising in themselves from this way, they define a circled space 17 between them. With the diaper 1 worn on the wearer's body, this space 17 rests between the wearer's crotch region and the body fluid absorbent structure 5 serving to isolate the residue absorbed by the body fluid absorbent structure 5 from the wearer's skin.

[00032] While the elastic members 42 for the crotch region will instead remain linearly extended between the abdominal sheet member 2 and the back sheet member 3 after their contraction, these elastic members 42 are pressed towards the side flaps 45 towards of the body fluid absorbent structure 5. Accordingly, the elastic members 42 for the crotch region being curved to describe semicircular arcs between the abdominal sheet member 2 and the back sheet member 3 so that the opposite side edges 41 of the sheet member crotch 4 are also curved to describe similar semicircular arches and thus define the peripheral edges of the respective leg openings.

[00033] As previously described, the section defined by the parallel segments 53 of the body fluid absorbent structure 5 in the abdominal sheet member 2 contracts more significantly than the section defined by the parallel segments 54 in the back sheet member 3, and consequently , the crotch sheet member 4 having an apparent width W2 on the side of the back sheet member 3 greater than the apparent width W1 on the side of the abdominal sheet member 2. Said apparent differential width of the crotch sheet member 4 results in an advantageous feature of the invention as will be readily understood from Figure 5 showing the diaper 1 from the front side. As shown, the peripheral edges 81 of the respective leg openings describe semicircular arcs extending outwardly in the transverse direction from the abdominal leaf member 2 towards the back leaf member 3. In other words, the leg openings 8 open favorably towards the diaper 1.

[00034] The curved segments 52 of the body fluid absorbent structure 5 are positioned apart towards the abdominal sheet members 2 and thus a section of the body fluid absorbent structure 5 extending on the front side of the crotch region (4) of the wearer having a relatively small dimension as measured in the transverse direction. With the aforementioned dimensional relationship, there is no anxiety that the body fluid absorbent structure 5 may be compressed in the user's crotch region and consequently the user may have the experience of feeling uncomfortable, even when the user (a) closes their legs. Furthermore, the side flaps 45 may be deformed keeping the wearer's legs moving even if the movement is vigorous and thus it is not understood that no release slot is formed between the wearer's legs and the peripheral edges 81 of the respective openings. legs through which bodily fluids can leak.

[00035] As will be apparent from Figure 6 schematically illustrating the pant-shaped diaper 1 from its rear side, the percentage of contraction of the body fluid absorbent structure 5 will be lower in the section thereof defined by the parallel segments 54 on the side of the dorsal sheet member than in the section thereof defined by the parallel segments 53 on the side of the abdominal sheet member. In this way, the section defined by the parallel segments 53 on the side of the member of the abdominal section will ensure its sufficient cross-sectional dimension to cover the buttocks of the wearer.

[00036] Now a diaper 1 according to a second embodiment of the invention will be described with reference to Figures 7 to 10. Figure 7 is a view showing the diaper 1 as developed flat, Figure 8 is a plan view showing the diaper with elastic members encircling the waist contracted, Figure 9 and Figure 10 are schematic diagrams showing the pant-shaped diaper 1A as viewed from the abdominal side and dorsal side, respectively. As will be understood from Figure 7, an important difference of this configuration from the first configuration lies in the fact that the curved segments 52 of the body fluid absorbent structure partially overlap the abdominal sheet member 2.

[00037] The crotch sheet member 4 in the second configuration is similar to that of the first configuration shown by Figure 1, except that positions in which the crotch sheet member 4 is attached to the abdominal sheet member 2 and the back sheet member 3, respectively, being placed apart towards the side of the abdominal sheet member 2. In this way, the longitudinal dimension L1 by which the body fluid absorbent structure 5 overlaps the abdominal sheet member 2 is greater than the longitudinal dimension L2 by which the body fluid absorbent structure 5 overlaps the backsheet member 3. Alternatively, it will be possible to change the positions in which the curved segments 52 are formed on the body fluid absorbent structure 5 so that the curved segments 52 can overlap an edge line B1 between the abdominal sheet member 2 and the crotch sheet member 4. On the other hand, the parallel segments 54 in the body fluid absorbent structure 5 overlaps an edge line B2 between the backsheet member 3 and the crotch sheet member 4. With this harmonization, the transverse dimension of the body fluid absorbent structure 5 will be smaller at edge line B1 than at edge line B2 .

[00038] The abdominal sheet member 2 and the back sheet member 3 respectively have constructions similar to those of the first configuration shown in Figure 1. Specifically, the elastic stress of the abdominal and dorsal rubber threads 61, 62 involved when the diaper 1 is flatly developed is higher in the abdominal sheet member than in the back sheet member 3. The materials as well as the joining modes of the respective sheet members are similar to those of the first configuration and a detailed description thereof will not be repeated here.

[00039] When the abdominal and dorsal rubber cords 61, 62 respectively are left contracted in the transverse direction as illustrated by Figure 8, the members of the front and back sheets 2, 3 and the crotch sheet member 4 retract in the transverse direction to from the flattened state indicated by the imaginary lines to the state indicated by the solid lines. The regions of the members of the front and back sheets 2, 3 extending outside the body fluid absorbing structure 5 are relatively easy to deform since these regions are not affected by the relatively high firmness of the body fluid absorbing structure 5.

[00040] This relationship can be verified by comparing a transverse length of the edge line B1 between the abdominal leaf member 2 and the leaf member of the crotch region 4 with a transverse length of the edge line B2 between the dorsal leaf member 3 and the crotch sheet member after the abdominal and dorsal rubber threads 61, 62 have contracted. In addition to the greater strain of the rubber threads 61 on the abdominal side, the relatively short length over which the dorsal sheet member overlaps the body fluid absorbent structure 5 leads to a dimensional relationship where the length of the B1 edge line is shorter. than the length of the edge line B2. Thus, the apparent dimension of the crotch sheet member 4 in the transverse direction will be greater at the edge line B2 with the back sheet member 3 than it will be at the edge line B1 with the abdominal sheet member 2, i.e. the width W2 on edge line B2 will be greater than width W1 on edge line B1 with abdominal leaf member 2.

[00041] More specifically, the leg openings 8 preferably open in front of the diaper 1 as will be seen in Figure 9 schematically illustrating the diaper from the abdominal side. In the event that the body fluid absorbent structure 5 of the same configuration is used for the first configuration as well as for the second configuration, the leg openings will still open in front of the diaper 1 and the inflexibility of the diaper around the wearer's legs will be still improved compared to the case of the first configuration. This is due to the fact that, as described above, the transverse dimension of the body fluid absorbent structure 5 at the edge line B1 will be greater in the second configuration than in the first configuration.

[00042] As will become apparent from Figure 10, schematically illustrating the pant-shaped diaper 1 from the dorsal side of the body fluid absorbent structure section 5 defined by the parallel segments 54 on the side of the backsheet member exhibiting a percentage of concentration lower than the percentage concentration exhibited by the body fluid absorbent structure section 5 defined by the parallel segments 53 on the side of the abdominal leaf member as the former with the figure being the case. Consequently, the cross-sectional dimension of the body fluid absorbent structure 5 is sufficiently greater in the section defined by the parallel segments on the side of the back sheet member than in the section defined by the parallel segments on the side of the abdominal sheet member to cover the wearer's buttocks. a desired way.

[00043] According to the second configuration, the curved segments 52 of the body fluid absorbent structure 5 partially overlap the edge line B1 between the abdominal sheet member 2 and the crotch sheet member 4 while the dorsal side of the parallel segments 54 of the body fluid absorbent structure 5 overlaps the edge line B2 between the backsheet member 3 and the crotch sheet member 4 so that the transverse dimension of the body fluid absorbent structure 5 at the edge line B1 is less than that of the edge line B2. In the flattened state, therefore, it will be possible to deform the body fluid absorbent structure so that the abdominal rubber threads 61 and the back rubber threads 62 can exhibit the same stress. It will also be possible to adjust the stress of the abdominal rubber threads 61 to be less than the stress of the dorsal rubber threads 62.

[00044] According to this second embodiment, the apparent width W1 of the crotch sheet member 4 along the edge line B1 in which the curved segments partially overlapping the abdominal sheet member 2 will necessarily be less than the width W2 along of the edge line B3 while the abdominal sheet member retracts under contraction of the abdominal rubber threads 61, It will not be essential, therefore, to set a percentage concentration of the abdominal sheet member 2 at a level higher than a percentage concentration of the dorsal leaf member 3.

[00045] While the three-piece disposable diaper 1 is characterized by its improved suitability to the wearer's body particularly in the region extending from the buttocks to the wearer's legs as described above on the basis of the first and second configurations, it should be understood that the The present invention will not be limited to these configurations but various modifications or variations may be devised by a person skilled in the art knowledgeable in the art without departing from the scope of the invention.

[00046] In one example of conceivable variants, the abdominal sheet member 2 and the back sheet member 3 may respectively be provided with a plurality of elastic members encircling the waist 6 so that the elastic members encircling the waist 6 extend across of the body fluid absorbent structure 5 being harmonized at closer intervals on the abdominal sheet member 2 than on the back sheet member 3. For example, the first configuration or the second configuration may be modified so that the abdominal rubber threads 61 are extended through the body fluid absorbent sheet 5 are matched at closer intervals than the dorsal rubber threads 62 on the back sheet member 3. Said modification will allow the abdominal rubber threads 61 and the dorsal rubber threads 62 to have the same elastic stress. In Figure 8, the number of dorsal rubber threads 62 extended on the body fluid absorbent structure 5 can be appropriately decreased to achieve the aforementioned modification.

[00047] It will further be possible to provide the backsheet member 3 with none of the elastic members encircling the waist 6 extending through the body fluid absorbent structure 5 or to increase the number of abdominal rubber threads 61 extended through the fluid absorbent structure body 5 with respect to the number of dorsal rubber threads 62 extended through the body fluid absorbent structure 5. Preferably for said modification, the abdominal and dorsal rubber threads 61, 62 have the same elastic stress and the abdominal rubber threads 61 extended through the body fluid absorbent structure 5 being matched at next intervals in which the abdominal and dorsal rubber threads 61 extended through the body fluid absorbent structure 5 are matched. Indeed, it will be essential that the elastic members encircling the waist 6 extended through the body fluid absorbent structure 5 should exhibit a higher percent concentration on the side of the abdominal sheet member 2 than on the side of the back sheet member 3.

[00048] An alternative construction will further be designed so that, elastic members encircling the waist 6 (i.e., the backsheet rubber threads 62) extend through the backsheet member 3, the elastic members encircling the waist 6 extend in the vicinity of the edge line B2 between the backsheet member 3 and the crotch sheet member 4 exhibiting a lower elasticity than the elasticity exhibited by the elastic members encircling the waist 6 extended through the remaining region of the backsheet member 3. In other words, it will be possible to construct the backsheet member 3 so that the percentage of contraction of the backsheet member 3 depends on at least the elastic members encircling the waist 6 extending in the vicinity of the line edge B2 between the backsheet member 3 and the crotch sheet member 4 exhibit a lower elasticity than the elasticity exhibited by the elastic members encircling the waist 6 extended across the remaining region of the backsheet member 3. The diaper 1 according to this variant is apparently similar to the diaper 1 illustrated by Figures 8 through 6 and thus not illustrated.

[00049] In order to differentiate the elasticity exhibited by the elastic members circling the waist or the percentage of contraction of the backsheet member 3 depending on the region as described above, some of the elastic members circling the waist 6 could be made using various means of treating the limbs Waist-circling elastics 6 present at the edge line B2 with the backsheet member 3. If any of the waist-circling elastic members are extended through the body fluid absorbent structure 5, these elastic members 6 are preferably made of non-elastic. It will thus be ensured that the width W2 on the side of the backsheet member 3 can be kept as wide as possible and leakage of body fluids due to folds which may otherwise be formed in the body fluid absorbent structure 5 can be prevented as there is no plus the possibility that the body fluid absorbent structure 5 may retract in the transverse direction on the side of the backsheet member 3.

[00050] Alternatively, it will be possible to make the elastic members surrounding the waist 6 partially non-elastic still on the side of the abdominal sheet member 2 and to ensure that the width W2 of the crotch sheet member 4 on the side of the back sheet member 3 is greater than the width W1 on the side of the abdominal sheet member 2. Assuming that the abdominal rubber threads 61 and the dorsal rubber threads 62 are made of the same material and have characteristics such as those of the material, the number and the percentage of common contraction for both, the relationship as described above will be achieved by sizing the span over which the dorsal rubber strands 62 are made of non-elastic to be greater than the span over the abdominal rubber strands 61 which are made of non-elastic.

[00051] When the elastic members encircling the waist 6 on the side of the abdominal sheet member 2 are partially made of non-elastic, the region to be flattened for the purpose of preventing urine leakage will preferably be made of non-elastic in view from the fact that the body fluid absorbent structure 5 supported on the side of the abdominal sheet member 2 serves for the absorption of urine. As a specific example, the elastic members encircling the waist can be made non-elastic along a peripheral edge of the body fluid absorbent structure 5 overlapping the abdominal sheet member 2 to ensure that leakage of urine possibly occurs in the transverse direction of the structure. body fluid absorbent 5 towards the leg openings can be safely prevented.

[00052] To cut the elastic members encircling the waist 6, a suitable trimmer can be used to cut the elastic members encircling the waist 6 together with the back sheet member 3. When said cutting treatment is adopted, those elastic members encircling the waist waist 6 extended through the body fluid absorbent structure 5 may be cut. When heat treatment is adopted to make the elastic members circling the waist 6 on the side of the backsheet member 3 non-elastic, the elastic members circling the waist 6 will preferably be made of thermoplastic elastomer as well known in the prior art as well as elastomer based on urethane or elastomer based on styrene.

[00053] Alternatively, the percentage of the elastic members encircling the waist 6 may be periodically varied when these elastic members encircling the waist 6 are joined to the backsheet member 3 such that the elastic members encircling the waist 6 are supported in the vicinity of the line of edge B2 with the dorsal leaf member 3 may have an elongation percentage lower than the elongation percentage of the elastic members encircling the waist 6 supported in the remaining region. In this way, the elasticity exhibited by the elastic members encircling the waist 6 may be varied depending on the region occupied by these elastic members 6. It will also be possible to adjust the elasticity exhibited by the elastic members encircling the waist 6 supported in the middle region along the central line. longitudinal M of the dorsal leaf member 3 to be lower than in the regions extending on both sides of the central line M.

[00054] With this harmonization, compared to the elasticity exhibited by the elastic members encircling the waist 6 supported in the vicinity of the edge line B2 between the back sheet member 3 and the crotch sheet member 4, the elasticity exhibited by the elastic members encircling the waist 6 supported in the remaining region will be relatively high. As a result, the elasticity of the elastic members encircling the waist 6 functions to enlarge the apparent transverse dimension W2 of the crotch sheet member 4 in the vicinity of the edge line with the abdominal sheet member 2 as the diaper 1 is formed into pants (see Figures 6 to 10).

[00055] In this case too, the contraction percentage of the elastic members surrounding the waist 6 on the side of the abdominal sheet member 2 can be adjusted to be greater than on the side of the back sheet member 3. The elasticity of the elastic members surrounding the waist girdle 6 in the vicinity of the edge line B2 with the backsheet member 3 may preferably be minimized. As a result, it will be possible to obtain the diaper 1 including the crotch sheet member 4 of which the width W2 on the side of the back sheet member 3 is greater than the side W1 on the side of the abdominal sheet member 2.

[00056] As yet another example of conceivable variants, the fluid body absorbent structure 5 could be constructed so that a section of the structure 5 overlaps the abdominal sheet member 2 more easily retracted than the section thereof overlapping the sheet member dorsal 3. Said effect could be achieved, for example, by adjusting a density of the fluff pulp constituting the body fluid absorbent structure 5 to be lower on the side of the abdominal leaf member 2 than on the side of the leaf member dorsal 3 so that the side of the abdominal sheet member 2 can be more suitable for compressive deformation.

[00057] Conceivable variants will not be limited to those described above. For example, it will be possible to use the backsheet member 3 having a longitudinal dimension greater than the longitudinal dimension of the abdominal sheet member 2 instead of using the backsheet and backsheet members 2, 3 which are the same in shape and size. . Alternatively, a rectangular or square sheet may be cut in two along a curve describing a sine wave or a flexible elastic line describing a sawtooth wave both extended in the transverse direction so that one of them is to be used as a member of the sheet. abdomen 2 and the other being used as a member of the backsheet 3. It will still be possible to obtain the abdominal sheet member 2 or the backsheet member 3 by folding a single sheet into two between which a plurality of rubber threads or other may be pressed.

[00058] While the shape of the crotch sheet member 4 is concerned, it will be essential that the opposing side edges 41 thereof extend in the longitudinal direction becoming parallel to each other when the diaper 1 is flatly developed and the shape of the ends longitudinally opposite them connecting these opposite side edges 41 to each other and may be linear, curved or flexible. Each of the liquid permeable sheets 43 and the liquid impermeable 44 may comprise either a single sheet or two or more sheets.

Claims (7)

1 .- “DISPOSABLE DIAPER”, symmetrical above a longitudinal centerline thereof, comprising a longitudinal direction and a transverse direction orthogonal to the longitudinal direction; a rectangular member of the abdominal sheet (2) and a rectangular member of the back sheet (3) extending parallel to each other in the transverse direction; and a rectangular crotch sheet member (4) including a body fluid absorbent structure (5) and extending in the longitudinal direction and joined to said abdominal sheet member (2) and said back sheet member (3) so as to connecting said abdominal (2) and dorsal (3) sheet members to each other wherein said crotch sheet member (4) has a transverse dimension smaller than that of said abdominal (2) and dorsal (3) sheet members disposable diaper, characterized in that said abdominal sheet member (2) and said back sheet member (3) are provided with elastic members (6) surrounding the waist attached thereto under tension in the transverse direction; a region of the abdominal sheet member (2) in which said elastic members (6) surrounding the waist are present and said crotch sheet member (4) overlaps one another; a region of the abdominal sheet member (2) in which said elastic members encircling the waist are present and said crotch sheet member (4) overlaps one another; opposite side edges (41) extending in the longitudinal direction on both sides of the crotch sheet member (4) being parallel to each other at least when the diaper is flatly open, said body fluid absorbent structure (5) having side edges (51) extending parallel to opposite side edges (41) of the crotch sheet (4) the opposite longitudinal side edges (51) comprise a pair of curved segments (52) which are curved into said body fluid absorbent structure (51) 5) so as to be symmetrical about the longitudinal centerline (M), the curved segments 52 are positioned apart towards the members of the abdominal sheet (2) said transverse dimension of the body fluid absorbent structure (5) is lower on the line edge (B1) with said abdominal sheet member (2) than in an edge line (B2) with said back sheet member (3) and an apparent width of said crotch region member s (4) as measured in the transverse direction after said elastic members encircling the waist are contracted and thereby said crotch sheet member (4) retracts together with said abdominal sheet member (2) and said back sheet member (3) be higher in an edge line with the dorsal leaf member (3) than in an edge line with the abdominal leaf member (2). 2.- "DISPOSABLE DIAPER" according to claim 1, characterized in that said opposite longitudinal side edges of the body fluid absorbent structure comprise a pair of opposing segments (53) extending parallel to each other on the side of the abdominal sheet, a pair of opposing segments (53) extending parallel to each other on said side of the back sheet member (3) and a pair of curved segments (52) extending parallel to each other between the parallel segments on the side of abdominal sheet member (2) and the parallel segments (54) on the side of said back sheet member (3) and being curved into the body fluid absorbent structure (5) so as to be symmetrical with respect to said centerline length of the diaper and said parallel segments (54) on the side of said backsheet member (3) overlap said backsheet member and said curved segments (52) overlap said sheet member a abdominal (2). 3 .- "DISPOSABLE DIAPER", according to claim 1, characterized in that said crotch sheet member (4) is provided along said opposite side edges of said crotch sheet member (4) with elastic members bonded thereto under tension. 4 .- "DISPOSABLE DIAPER", according to any one of the preceding claims, characterized by the fact that said elastic members surrounding the waist exhibit along their segments that extend through said body fluid absorbent structure on the side of said member of abdominal sheet (2) a greater stretch tension on the side of said abdominal sheet member (2) than on the side of said back sheet member (3) in the flat open disposable diaper. 5 .- “DISPOSABLE DIAPER”, according to any one of the preceding claims, characterized by the fact that said abdominal leaf member (2) and said dorsal leaf member (3) are provided with said elastic members surrounding the waist tensioned thereto so that said elastic surrounding waist members extend across said body The fluid absorbent structure on the side of said abdominal sheet member (2) is arranged at intervals closer than the intervals of said members waist-circling elastics extending through said body fluid absorbent structure on the side of said backsheet member. 6 .- "DISPOSABLE DIAPER", according to any one of the preceding claims, characterized by the fact that said elastic members surrounding the waist that extend through said dorsal sheet member (3) exhibit in the vicinity of the boundary line between the Said backsheet member (3) and said crotch sheet member (4) exhibit a lower elasticity than an elasticity exhibited by such elastic waist-surrounding members in the remaining region. 7 .- "DISPOSABLE DIAPER", according to any one of the preceding claims, characterized by the fact that said disposable diaper has been molded into underwear by joining opposite side edges that extend in the longitudinal direction on both sides of said sheet element abdominal (2) to opposite side edges extending in the longitudinal direction on either side of said dorsal (3) sheet member so that these abdominal (2) and dorsal (3) sheet members are annularly joined to each other to define an opening in the waist, while said abdominal (2) and dorsal (3) sheet members annularly joined in this manner cooperate with said hook sheet member joined to these abdominal (2) and dorsal (3) sheet members. to define a pair of leg openings (8).

Images