FR2701207A1 - Disposable absorbent diaper (nappy) with improved leaktightness - Google Patents

Abstract

Diaper having improved leaktightness whatever the position of the user and in particular when the latter sleeps on his/her side. The diaper according to the invention comprises a fluid-impermeable outer support sheet 1, an absorbent pad 2, a liquid-permeable inner cover sheet 3, first longitudinal elastic elements 8, two side flaps 10 extending above the pad, second longitudinal elastic elements 15 fixed on the flaps in proximity to their distal edges 14, openings 16 for passage of the legs of the user, which openings are made in the region of the flaps corresponding to the crotch region 5 of the diaper and which are transversely offset in the direction of the distal edges 14 of the flaps with respect to the longitudinal mid-axis of the diaper, and third elastic elements 17 which are fixed, tensioned, on the flaps between a longitudinal edge of the openings and the proximal edges 13 of the flaps. Application to disposable absorbent diapers.

Description

 Disposable absorbent diaper with improved waterproofing.

 The present invention relates to a hygiene article consisting of a disposable absorbent diaper intended for young children or incontinence, of the type comprising an absorbent pad disposed between an outer sheet of waterproof support and an inner permeable sheet.

 Hygiene articles of this type are known, for example, from patent application GB-A-2.161.O59 (Kimberly-Clark). According to this document, two lateral sealing flaps extend, above the absorbent pad, directed towards each other so that their elasticized distal edges are located close to each other. The two lateral sealing flaps are produced by a double folding of the liquid-permeable inner sheet covering the liquid-impermeable support sheet as well as the absorbent pad fixed on this support sheet. At their two ends corresponding to the two transverse edges of the diaper, the flaps are fixed so as to always be turned inwards, one towards the other, without being able to fold outwards, for example during the positioning of the article d hygiene on the user. These side flaps improve the sealing of the hygiene articles in the lateral direction, in particular in the crotch area. On the other hand, risks of leakage remain in the two belt areas.

It is also known, for example from the patent application
GB-A-2,159,693 (Kimberly-Clark), to provide in each belt zone of such a hygiene article, a pocket constituted by a flap extending from a transverse edge of the hygiene article in direction of the opposite transverse edge, the distal edge of this flap possibly being elasticated. These pockets improve waterproofing only in the belt areas.

I1 has also already been proposed to improve, on the same hygiene article, both the lateral tightness, both in the crotch area, and the tightness in the two belt areas. Thus, according to US-A-4,662,877 (William), the inner sheet of such a hygiene article is covered with an additional sheet, comprising above the absorbent cushion a rectangular opening or cut, both of which longitudinal edges are elasticized. It should be noted that according to this document, the additional sheet is fixed to the permeable inner sheet along two opposite transverse edges corresponding to the transverse edges of the hygiene article and along two opposite longitudinal edges situated outside the elastic elements d 'crotch of the hygiene article, which elastic elements are themselves located outside of the opposite longitudinal edges of the absorbent pad. Such an additional sheet comprising a rectangular opening with elasticated longitudinal edges is not entirely satisfactory, in particular because of the width of this opening (of the order of 12 cm for a length of 30 cm). In addition, because of the width of the opening of the additional sheet, this sheet must itself be wider than the absorbent pad to provide two side flaps of sufficient width, which means that a large amount of material is consumed for this sheet. However, in the case of absorbent hygienic articles to be thrown away like diapers, it is essential to reduce as much as possible the quantities of materials used, and therefore the cost price of the articles. It has also already been proposed, for example by patent application EP-A-0376022 (The
Procter and Gamble), to provide an absorbent diaper with two side sealing flaps and two belt pockets.

However, the belt pockets are, in this document, produced by two added transverse bands, which complicates the manufacture of diapers, in particular when the latter are produced continuously in the longitudinal direction.

 It has also been proposed in French patent application FR-A-92 10601 (Peaudouce) to provide the diaper with two side flaps extending above the absorbent pad so that their proximal edges are connected to the sheet inner along longitudinal lines located substantially above the longitudinal edges of the absorbent pad or recessed inwardly relative to said edge and that their distal elasticized edges are located near one another. According to this document, the side flaps are interconnected at their distal edges from the transverse edges of the diaper at least to the corresponding transverse edges of the absorbent pad, thus forming a peripheral sealing barrier around the entire periphery of the absorbent cushion.

 However, it is still desirable to further improve the tightness of such diapers. More specifically, it would be desirable to obtain a diaper whose sealing is not modified by the position of the user and, in particular it would be desirable to produce a diaper having better sealing when the user sleeps on its side.

 The present invention therefore aims to achieve a disposable absorbent pantyhose which, while being of a simple structure and manufacture has an improved sealing barrier, effective whatever the position of the user and in particular when the user is sleeping on their side.

 The disposable absorbent diaper according to the invention comprises an outer sheet of support impermeable to liquids, which may for example have the general shape of an hourglass including a crotch zone preferably of reduced width between two end zones, an absorbent cushion generally of dimension smaller than said support sheet is fixed thereto and an interior cover sheet permeable to liquids covering the absorbent cushion and fixed to the support sheet. First longitudinal elastic elements are fixed, in the stretched state, to the support sheet, outside the longitudinal edges of the absorbent pad.

 Two lateral flaps are arranged symmetrically on either side of a median longitudinal axis of the diaper and extend at least above the absorbent pad while being connected by a first of their longitudinal edges, above the pad, to said cover sheet along longitudinal lines. Second longitudinal elastic elements are fixed, in the stretched state, to the flaps near the second longitudinal edges of said flaps. The flaps have an opening for the passage of the legs of the user formed in an area of said flaps corresponding to the crotch area of the diaper and which is offset transversely relative to the median longitudinal axis of the diaper in the direction of the second longitudinal edges of said flaps. Third longitudinal elastic elements are preferably fixed, in the stretched state, on the side flaps near the openings between a longitudinal edge of said openings and the first longitudinal edges of said flaps.

 The openings preferably have an elongated shape in the longitudinal direction, in particular the shape of flattened ovals in the longitudinal direction, but may have any other suitable shape, such as, for example, circular. Generally, these openings have a length less than the length of the crotch area.

however, obviously these openings must be dimensioned to allow the passage of the legs of the user.

 In general, the third elastic elements have a length between the length of the openings and the length of the crotch area and preferably a length greater than that of the openings. As a recommended method, these third elastic elements can be fixed to the flap so as to conform to the outline of their respective openings. These third elastic elements may also include one or more elastic elements fixed in the stretched state, near a longitudinal edge of each of the openings.

 In an embodiment of the disposable absorbent diaper according to the invention the two lateral flaps arranged symmetrically on either side of the median longitudinal axis of the diaper extend above the absorbent pad so that their proximal edges are connected to said cover sheet along longitudinal lines located substantially above the longitudinal edges of the absorbent pad or recessed inwardly relative to said edges and that their distal edges are located near one of the The second longitudinal elastic elements are fixed in the stretched state on the flaps near their distal edges, said lateral flaps being interconnected at their distal edges from the transverse edges of the diaper at least up to at the transverse edges of the absorbent pad, to form a peripheral sealing barrier around the entire periphery of the absorbent pad, and opens it rture for the passage of the legs of the user formed in an area of each of said flaps corresponding to the crotch area of the diaper is offset transversely towards the distal edges of said flaps relative to the median longitudinal axis of the The third elastic elements are fixed in the stretched state on the side flaps near the openings, between a longitudinal edge of said openings and the proximal edges of the flaps.

 In another embodiment of the invention, the two lateral sealing flaps may for example each consist of a section of sheath fixed in the flattened state # on the cover sheet of the diaper along a line longitudinal formed by the proximal edge of the flap and along the two transverse edges of the diaper, an opening having the shape of a flattened oval being formed in the zone of the flap corresponding to the crotch zone of the diaper being transversely offset in the direction of the distal edges of the flap, at least one elastic element being fixed in the stretched state in said sheath along a longitudinal line constituting the distal edge of the flap, and at least one elastic element being fixed in the stretched state in said sheath along a longitudinal line between the opening and the proximal edge of the flap. The two layers of the sheath are joined together at their proximal ends and on the e around the opening for example by gluing, or by heat sealing when the sheath is made of a heat sealable material.

 According to another embodiment, the lateral sealing flaps consist of the same section of tape covering the cover sheet over the entire length of the diaper and on the middle part of the width of the layer while being attached to the cover sheet along its two transverse edges corresponding to the transverse edges of the diaper and along its two longitudinal edges constituting the two proximal edges of the two flaps. This section of tape has, over a median part of its length, a longitudinal median slot whose two edges are elasticized by longitudinal elastic elements stretched to constitute the distal edges of the two lateral sealing flaps. An opening preferably having the shape of a flattened oval is formed in the area of this section corresponding to the crotch area of the diaper by being offset transversely towards the distal edge of the flap.

 According to a variant the two lateral sealing flaps each consist of a section of tape covering the cover sheet over the entire length of the diaper and on the middle part of the width of the diaper while being attached to the cover sheet along its two transverse edges corresponding to the transverse edges of the diaper and along its two longitudinal edges constituting the proximal edges of the two flaps. One or more longitudinal elastic elements are fixed, in the stretched state, near the distal edge of the strip section. The distal edge of the ribbon is folded so as to form a flap covering the second longitudinal elastic element (s). An opening preferably having the shape of an oval flattened in the longitudinal direction is formed in the region of the section of ribbon corresponding to the crotch area of the diaper, being transversely offset towards the distal edge. At least one longitudinal elastic element having a length between the length of cover and the length of the crotch area and preferably a length greater than that of the opening, is fixed, in the stretched state, between the opening and the proximal edge of the ribbon section.

 The opening may be provided by any suitable means, for example by cutting the opening in whole or in part by mechanical methods, laser cutting or any other process well known in the art.

 In this variant, the opening can be advantageously provided by retaining a portion of the yoke cut from the section of ribbon, integral with the rest of the ribbon on the side of the proximal edge of this ribbon, this integral portion can then be folded so as to form a flap covering at least the elastic element situated between the opening and the proximal edge of the ribbon, and fixed to the ribbon, for example by gluing or heat-sealing.

 Such an opening and such a flap can, for example, be formed by providing a longitudinal slot of the desired length in the section of ribbon, at the desired location for the opening, and by providing slots at each end of this slot. arc-shaped radials which meet in the direction of the distal edge of the flap and which do not meet in the direction of the proximal edge of the flap, thus leaving part of the cut yoke integral with the rest of the section of ribbon to form the flap .

 According to yet another embodiment, the two lateral sealing flaps may be constituted by the cover sheet itself having, over a median part of its length, a longitudinal slot whose two longitudinal edges are elasticized by elastic elements fixed to the tense state. In this case, a section of tape of width at least substantially equal to the width of the absorbent cushion is disposed between the cover sheet and the cushion over the entire length of the diaper in the middle part of the width thereof. .

 As a variant, the two lateral sealing flaps consist of a section of tape forming one half of the cover sheet.

 As before, in these two cases, an opening is formed in a similar manner in the cover sheet, on either side of the median longitudinal slot or of the distal longitudinal edges and elastic elements are arranged, in the stretched state, as described above, between the apertures and the proximal longitudinal edges of the absorbent pad.

 More particularly, in an embodiment using the cover sheet to form the lateral sealing flaps, the disposable absorbent panty layer comprises an outer support sheet impermeable to liquids, including a crotch zone between two end zones, an absorbent cushion attached to said support sheet, an intermediate liquid-permeable sheet disposed on the absorbent pad over the entire length of the diaper and of width at least equal to the width of the absorbent pad in the crotch area, and a sheet of inner cover impermeable to liquids covering said intermediate sheet. The cover sheet is fixed on the one hand to the outer support sheet and on the other hand to the intermediate sheet both on the two transverse edges of the diaper and following two longitudinal lines offset from the longitudinal edges of the absorbent pad in the area and crotch. First longitudinal elastic elements are fixed, in the stretched state, to the support sheet outside the longitudinal edges of the absorbent pad. The cover sheet has a median longitudinal slot on the middle part of the length of the diaper defining in the cover sheet two lateral sealing flaps. Second elastic elements are fixed, in the stretched state, on the external face. from the two edges of the slot extending to the transverse ends of the diaper thus constituting the distal longitudinal edges of said flaps, the longitudinal fixing lines of the cover sheet constituting the longitudinal longitudinal edges of said flaps. Openings for the passage of the legs of the user are provided in an area of said side flaps corresponding to the crotch area of the diaper being offset transversely relative to the median longitudinal axis of the panty towards the edges longitudinal distal of said flaps.

Third longitudinal elastic elements are fixed, in the stretched state, to the side flaps near the openings between a longitudinal edge of said openings and the proximal longitudinal edges of the side flaps.

 In the case where the longitudinal elastic elements ensuring the elasticity of the distal edges of the lateral sealing flaps and the longitudinal elastic elements ensuring the elasticization between the openings and the proximal edges of the lateral flaps are fixed inside sheaths or flaps, it may be advantageous to fix them only at their ends to said sheaths or flaps so that the elastic elements can, between these ends, slide in said sheaths or flaps.

The following description refers to the accompanying drawings which respectively represent
Figure 1, a plan view of the inner face of a diaper, partially cut away, according to a first embodiment of the invention;
FIG. 2, a sectional view on a larger scale made along the line II-II of FIG. 1,
Figure 3, a sectional view on a larger scale taken along the line m-III of Figure 1;
Figure 4, a plan view of the inner face of a panty diaper, partially cut away, according to another embodiment of the invention;
Figure 57 a sectional view on a larger scale taken along the line IV-IV of Figure 4;
Figure 6, a plan view of the inner face of a cover, partially cut away, according to another embodiment of the invention;
Figure 7, a sectional view, on a larger scale, taken along the line Vll-Vll of Figure 6;
Figure 8, a plan view of the inner face of a cover, partially cut away, according to another embodiment of the invention;
Figure 9, a sectional view on a larger scale taken along the line IX-IX of Figure 8;
FIG. 10, a plan view of the interior face of a panty cover, partially cut away, according to yet another embodiment of the invention; and
FIG. 11 is a sectional view, on a larger scale, taken along the line MM of FIG. 10.

 There is shown in Figures 1 to 3 a first embodiment of the diaper according to the invention which comprises in known manner, a support sheet 1 impermeable to liquids, an absorbent pad 2, for example in fluff cellulose pulp , possibly with incorporation of so-called super-absorbent polymer material, a cover sheet 3 permeable to liquids, for example a fleece of nonwoven. The two sheets I and 3 have the same dimensions and the same hourglass shape, that is to say a rectangular shape with two opposite lateral notches 4 delimiting, in the direction of the length of the diaper, a zone 5 of crotch of reduced width between two end zones 6 and 7 of increased width.

 The absorbent cushion 2 disposed between the two sheets 1 and 3 also has an hourglass shape but of smaller size than the sheets I and 3 which are interconnected for example by bonding around the entire periphery of the cushion 2.

 First longitudinal elastic elements 8, each consisting for example of one or more elastic strands or threads or of an elastic strip, are fixed in the stretched state to the support sheet 1, at least in the crotch region 5, between the bottom of the notches 4 of the sheet 1 and the bottom of the corresponding notches of the absorbent pad 2.

 Furthermore, adhesive fasteners 9 are fixed to the opposite lateral edges of the end zone 6 constituting the rear part of the diaper.

 Two lateral sealing flaps 10 are fixed on the cover sheet 3, above the absorbent pad 2, over the entire length of the diaper. The arrangement of the elements described above is of conventional structure and this is the reason why we have not shown, in order not to overload the drawings, the means of assembly, in particular by gluing, of these different elements constitutive.

Each flap 10 is constituted by a section of sheath 11 of an air permeable material, for example a nonwoven preferably hydrophobic or impermeable to liquids, formed of a section of tape
It folded and closed on itself by a longitudinal line 12 of bonding or welding. The sheath section 10 is fixed to the sheet 3 by a longitudinal line 13 of bonding or welding which extends over the entire length of the diaper, preferably in a position slightly recessed inwards relative to the edge of the absorbent pad 2 in the crotch area 5 (see Figure 2).

 Each sheath section II thus fixed to the cover sheet 3 is disposed in the flattened state on the cover sheet 3 so as to extend, from the proximal edge defined by the fixing line 13, inwards at less substantially to the middle of the width of the absorbent pad 2, so that the distal edges 14 of the two opposite flaps 10 touch or are very close to each other. At least one second longitudinal elastic element 15 is disposed in the stretched state inside the sheath section 11 of each flap 10 near the distal edge 14 of the latter. An opening having the shape of a flattened oval in the longitudinal direction, of length less than the length of the crotch area of the diaper, is provided in the sheath section 11 of each flap 10, being offset transversely in the direction of the distal edge 14 of the flap 10 relative to the median longitudinal axis of the diaper. The sheath section 11 is joined around the periphery of the opening 16 by gluing or welding, for example by heat-sealing in the case of a sheath made of heat-sealable material. At least one third longitudinal elastic element 17, of length greater than the length of the opening but at most equal to the length of the crotch area, is disposed in the stretched state in the sheath section, in the vicinity of the opening 16, between this opening and the proximal edge 13 of the flap 10. It should be noted that the second longitudinal elastic element 15 which extends over the entire length of the flap 10, and therefore over the entire length of the cover, is fixed to the sheath section 11 only at the two longitudinal ends, being free to slide between said two ends. Likewise, the third elastic element 17 can only be fixed to the sheath 11 at its ends and, consequently, can slide freely between said two ends.

 The sheath section 11 of each flap is also fixed to the cover sheet 3, in the flattened state, at the location of the opposite transverse edges of the diaper by bonding lines 18, visible in FIG. 3 .

 Finally, the two opposite flaps 10 are interconnected at their distal edges 14, from the two opposite transverse edges of the diaper to beyond the two opposite transverse edges corresponding to the absorbent pad 2 by fixing zones 18 ′, for example by gluing, visible in FIGS. 1 and 3.

 When the diaper thus formed is worn by the user who has passed his legs through the openings 16, and takes a curved shape in a trough, the elastic elements 15 and 17 tend to lift the flaps 10 relative to the absorbent cushion 2 and thus separate the distal edges 14 of the two flaps 10, to an extent which increases from the transverse edges of the diaper towards the middle of the crotch area 5 as indicated in dashes in FIG. 2. The two flaps 10 opposite constitute the two longitudinal sealing barriers and, due to their reciprocal connection in the two end zones 6 and 7, also form sealing pockets, in these zones, pockets whose depth depends on the length of the fixing zones 18 '. In addition, due to the openings 16 and elastic elements 17 which adapt to the user's thighs, a sealing barrier is created on the inner face of the thighs. e the user, making it possible to more effectively prevent leakage of urine or saddle, in particular, when the user sleeps on his side.

 In the embodiment according to Figures 4 and 5, the side flaps 10 are constituted by a single strip section 19 disposed on the cover sheet 3, over the entire length of the pantyhose, over a width substantially equal to the width of the absorbent pad 2 in the crotch area 5. The strip section 19 made of an air permeable material is preferably hydrophobic or impermeable to liquids and is fixed to the cover sheet 3 by two longitudinal gluing lines 13 and by two transverse bonding lines corresponding to lines 18 of the embodiment of FIGS. 1 to 3.

 The strip section 19 comprises in the middle part of its length, a longitudinal slot 20, the two edges of which are provided with longitudinal elastic elements 15 fixed, in the stretched state, on the respective edges of the strip section 19. thus the elasticized distal edges of two flaps 10, the proximal edges of which are defined by the bonding lines 13. As previously, openings 16 having the shape of flattened ovals of length less than the crotch area are formed symmetrically in the strip section 19 on each side of the median longitudinal slot being offset transversely in the direction of this median slot 20 of the strip section 19. Similarly, elastic elements 17 of length greater than the length of the openings 16 but less than the length of the crotch area 5 are fixed, in the stretched state, symmetrically with respect to the median longitudinal slot 20 between the openings s 16 and the proximal edges 13 of the strip section 19.

 In the two end zones 6 and 7 of the diaper, the section of ribbon 19 which is not split forms belt pockets, the depth of which depends on the unsplit length of the section of ribbon 19 in each end zone 6 , 7.

 In this embodiment, when the diaper is worn by the user who has passed his legs through the openings and takes a curved trough shape, the elastic elements 15 lift the flaps 10 so that the distal edges 14 of these flaps move apart in the crotch region 5 as indicated by dashes in FIG. 5. Also, the openings 16 and the elastic elements 17 adapting to the user's thighs cooperate to form a sealing barrier on the internal face thighs of the user which more effectively prevents leakage of urine or stool, especially when the user sleeps on his side.

 In Figures 6 and 7 there is shown an embodiment of the cover layer according to the invention which is similar to that of Figures I to 3 but in which the sheath sections 11 have been replaced by sections of tape. In addition, the distal edge of the ribbon section has been folded outwards to form a flap 22 which, as visible in FIG. 5, can be fixed for example by an adhesive line 23, in the folded state, thus constituting a narrow sheath in which the longitudinal elastic element 15 is fixed in the stretched state 15. On the other hand, a flap 24 is also provided fixed, for example by a gluing line 25, in the folded state, which constitutes thus a narrow sheath in which is fixed, in the stretched state, the longitudinal elastic element 17. Such a flap 24 can be easily produced during the cutting of the openings 16 while retaining a portion of the cut yoke to form these openings 16 secured to the rest of the ribbon section 19 over a small distance opposite the proximal edge of the ribbon section and by folding or folding outward this remaining portion of the yoke.

 In the embodiment according to FIGS. 8 and 9, there is a diaper having the same general structure as according to the preceding examples (support sheet 1, absorbent pad 2, cover sheet 3, hourglass shapes of the sheets 1 and 3 of cushion 2, longitudinal elastic elements 8 in the crotch area). This diaper also has lateral sealing flaps 10 which, however, here consist of the material of the cover sheet 3, which comprises, on the median part of the length of the diaper, a median longitudinal slot 26 Obviously, in this case the cover sheet is made of a material impermeable to liquids. Two elastic elements 15 are fixed, in the stretched state, on the external face of the two edges of the slot 26 extending as far as two transverse ends of the pantyhose. Openings 16 similar to the openings described above are formed on either side of the slot 26 in the flaps 10 of the cover sheet 3. Also, elastic elements 17 are fixed, in the stretched state, as previously on the flaps 10 between the openings 16 and the longitudinal edge of the cushion. In addition, a section of tape 27 made of a material permeable to liquids, for example a nonwoven, is arranged, over the entire length of the diaper, in the middle position between the absorbent pad 2 and the cover sheet 3, over a width at least equal to the width of the absorbent pad 2 in the crotch area. This section of tape 27 is fixed to the support sheet 1 on the two transverse edges of the diaper. The cover sheet 3 is also fixed to this section of tape 27 on the one hand on the two transverse edges of the diaper and on the other hand along two longitudinal lines 28, for example gluing lines, located in a position slightly offset from the longitudinal edges of the absorbent pad 2 in the crotch area 5. These attachment lines 28 define the proximal edges of the flaps 10, the distal edges 14 of which are provided with elastic elements 15, are defined by the slot 26 .

 The embodiment of FIGS. 10 and 11 differs from the embodiment of FIGS. 8 and 9 in that the cover sheet is made up of two sections, the distal edges of which form, over their entire length, two double folds 30 in Z, and the elastic elements 15 running along the distal edges 14 of the flaps 10 are fixed in the stretched state by gluing in the upper folds of these double folds 30, the two folds of each double fold 30 being secured one to the other by gluing or any other means so as to stiffen the cover sheet 3 at this location.

 It goes without saying that the embodiments shown and described have only been given by way of illustrative and nonlimiting example and that numerous modifications and variants are possible within the scope of the invention.

 Thus, in the embodiment of Figures 4 and 5, and 8 to 11, it would be possible to form a flap surrounding the elastic element 17 similar to the flap 24 of the embodiment of Figures 6 and 7. Similarly, the double folds 30 of the cover sheet 3 according to FIGS. 10 and 11 could also be used in the embodiment of FIGS. 6 and 7.

 It should be noted that in all the embodiments shown and described, the flaps 10 are advantageously constituted by a material which is breathable, but preferably hydrophobic or impermeable to liquids, such as a hydrophobic nonwoven or having a coating. waterproof.

 By providing openings such as openings 16 in the sealing flaps and by having elastic elements such as elastic elements 17 near these openings, a liquid impermeable barrier is thus obtained extending over the entire periphery of the cushion. absorbent, effectively suppressing leakage of urine and / or faeces both around the wearer's legs, i.e. in the crotch area 5, and at the waist, ie in the end zones 6 and 7, whatever the position of the user and in particular if he sleeps on his side.

 It will also be noted that in the present description, any element of the diaper directed towards the outside when the diaper is worn by the user has been qualified as "exterior". On the contrary, the term "interior" has been used to describe any element located towards the user when the diaper is used.

Claims (9)

 1. Disposable absorbent diaper, comprising an outer sheet (I) of impermeable support for liquids, including a crotch zone (5) between two end zones (6, 7), an absorbent pad (2) fixed on said sheet support, an inner cover sheet (3) permeable to liquids covering the absorbent pad and fixed to said support sheet, first longitudinal elastic elements (8) fixed, in a stretched state, to the support sheet, to the outside the longitudinal edges of the absorbent pad, and two lateral flaps (10) arranged symmetrically on either side of a median longitudinal axis of the diaper, extending at least above the absorbent pad and connected by a first of their longitudinal edges (13), above the cushion, to the cover sheet along longitudinal lines, second elastic longitudinal elements (15) fixed, in a stretched state, on the flaps near the secon ds longitudinal edges (14) of said flaps, characterized in that said flaps (10) each further comprise an opening (16) for the passage of the user's legs formed in an area of the side flaps (10> corresponding to the crotch area (5) of the diaper and which is offset transversely relative to the median longitudinal axis of the diaper in the direction of the second longitudinal edges (14) of said flaps (10), and of the third elastic elements longitudinal (17) fixed, in the stretched state, on the side flaps near the openings (16) between a longitudinal edge of said openings and the first longitudinal edges of the side flaps.  2. Diaper according to claim 1, characterized in that the two side flaps (10) extend above the absorbent pad so that their first longitudinal edges (13) are connected to the cover sheet along lines longitudinal located substantially above the longitudinal edges of the absorbent pad or recessed inwardly relative to said edges thus constituting the proximal edges of said flaps and that their second longitudinal edges (14) are located close to each other thus constituting the distal edges of said flaps, the second longitudinal elastic elements (15) are fixed to the flaps near their distal edges (14), said flaps being interconnected at their distal edges from the transverse edges of the panty layer at least to the corresponding transverse edges of the absorbent pad (2), thus forming a peripheral sealing barrier over the entire periphery of the absorbent pad, and the third longitudinal elastic elements (17) are fixed to the side flaps between said longitudinal edges of the openings (16) and the proximal edges (13) of the flaps.  3. Disposable absorbent diaper comprising an outer sheet (1) of impermeable support for liquids, including a crotch zone (5) between two end zones (6, 7), an absorbent pad (2) fixed to said backing sheet, a liquid permeable intermediate sheet (27) disposed on the absorbent pad over the entire length of the diaper and having a width at least equal to the width of the absorbent pad in the crotch area, a cover sheet inner (3) impermeable to liquids covering said intermediate sheet and fixed on the one hand to the outer support sheet (1) and on the other hand to the intermediate sheet both on the two transverse edges of the diaper and following two longitudinal lines (28) offset from the longitudinal edges of the absorbent pad in the crotch area, first longitudinal elastics (8) fixed, in a stretched state, to the support sheet outside laughing at the longitudinal edges of the absorbent pad, said cover sheet comprising on the median part of the length of the diaper a median longitudinal slot (26) to form in the cover sheet two lateral sealing flaps (10), second elastic elements (15) fixed, in the stretched state, on the external face of the two edges of the slot (26) extending to the transverse ends of the diaper thus constituting the distal longitudinal edges (14) of said flaps, the longitudinal fixing lines (28) of the cover sheet constituting the proximal longitudinal edges of said flaps, characterized in that said flaps (10) each further comprise an opening (16) for the passage of the legs of the user in an area of said side flaps corresponding to the crotch area of the diaper being offset transversely relative to the median longitudinal axis of the diaper in the direction of the distal longitudinal edges of said flaps, and of the third longitudinal elastic elements (17) fixed, in the stretched state, to the side flaps near the openings between a longitudinal edge of said openings and the longitudinal longitudinal edges side flaps.  4. Diaper according to any one of claims 1 to 3, characterized in that the openings (16) are of length less than the crotch area (5).  5. Diaper according to any one of claims 1 to 4, characterized in that the openings (16) have the shape of ovals flattened in the longitudinal direction.  6. Diaper according to any one of claims 1 to 5, characterized in that the third elastic elements (17) are of length between the length of the openings (16) and the length of the crotch area ( 5).  7. Diaper according to any one of claims 1 to 6, characterized in that the third elastic elements (17) follow the outline of the openings (16).  8. Diaper according to any one of claims 1 to 7, characterized in that flaps (22) fixed to the flaps (10) cover the second elastic elements (15).  9. Diaper according to any one of claims 1 to 8, characterized in that flaps (24) fixed to the flaps (10) cover the third elastic elements (17).