Abstract:
An absorbent disposable undergarment includes an outer garment, such as pants, in combination with a detachable absorbent pad attached inside thereof. First suspending flaps hang down from an inner side of a stretchable waist-opening peripheral edge of the pants toward a crotch section of the pants. The first suspending flaps are provided with first fastener elements that are disposed remote from the waist opening of the pants. Second suspending flaps extend upwardly from longitudinally opposite ends of the absorbent pad. The second suspending flaps are provided with second fastener elements, that are adapted to mate with the first fastener elements, and are disposed remote from the core of the pad. These second fasteners are releasably engaged with the first fasteners.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to disposable absorbent undergarments and, more particularly, to undergarments of a pants type, such as disposable diapers, training pants for babies, incontinence pants, and the like. 
     U.S. Pat. No. 4,597,760 discloses a body fluid absorbent garment comprising an overgarment and a body fluid absorbent insert adapted to be detachably attached to the overgarment. The body fluid absorbent insert is used as a disposable diaper or reusable diaper. The insert comprises a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core. The insert is formed with adhesive regions at four corners of its lower surface and is adapted to be releasably fastened to predetermined regions provided on the upper surface of the overgarment. 
     In the body fluid absorbent undergarment described above circumferential stretchability is provided along a peripheral edge of a waist opening thereof for ease of wearability. However, if the peripheral edge is provided with such circumferential stretchability in the pants type garment having a waist-opening and a pair of leg-openings, it is necessary that a plurality of gathers be formed along the peripheral edge. When the above-mentioned known technique is applied to such an undergarment such that an absorbent pad corresponding to the insert may be detachably attached to the pants corresponding to the overgarment adjacent the waist-opening, the gathers formed along the peripheral edge extending along the waist line obstruct operation of the attachment and the pad can not be attached to the pants over an area required to achieve a reliable attachment. This deficient attachment area will result in an inadequate fastening force and an apprehension that the pad might unintentionally detach from the pants. In addition, the presence of the gathers in the fastening regions will make it difficult to find the fastening regions. 
     In view of the problem described above, it is a principal object of the invention to provide an undergarment having a circumferentially stretchable waist line peripheral edge which allows the absorbent pad to be easily fastened to the pants without apprehension that the pad might unintentionally detach from the pants. 
     SUMMARY OF THE INVENTION 
     The object set forth above is achieved, according to the invention, by an undergarment having a front section, rear section, and crotch section interposed therebetween. The undergarment comprises a pair of leg-openings and a circumferentially stretchable waist-opening. A body fluid absorbent pad, including a topsheet, a backsheet and an absorbent panel disposed therebetween extends longitudinally in and from the crotch section into proximity to the front and rear sections. In accordance with the invention, a pair of first suspending flaps are carried on inner sides of the front and rear sections in circumferentially middle regions thereof. The first suspending flaps hang down from and beyond a peripheral edge region of the waist-opening toward the crotch section and have provided at free ends thereof, first fastening means which are more rigid than the first suspending flaps. The pad has second suspending flaps, formed of at least one of the topsheet and the backsheet or both, extending outward beyond longitudinally opposite ends of the panel. The second suspending flaps are provided with second fastening means which are more rigid than the second suspending flaps and are adapted to be releasably fastened to the first fastening means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of incontinence pants partially broken away, of a specific embodiment of the inventive undergarment; 
     FIG. 2 is a sectional view taken along line II—II in FIG. 1; and 
     FIG. 3 shows the incontinence pants longitudinally opened out in a plan view with parts broken away. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Incontinence pants  1 , as depicted in FIG. 1, comprise a main body  2  and an absorbent pad  3  detachably attached to the main body. The main body  2  has a front section  6 , a rear section  7 , and a crotch section  8  interposed therebetween. Transversely opposite side edges of the front and rear sections  6 ,  7  are bonded together, for example, along respective heat-seal regions  11  each intermittently extending in their vertical direction so as to form a waist-opening  9 . The front and rear sections  6 ,  7  are provided along respective peripheral edge regions  16  of the waist-opening  9  with first elastic members  12 ,  13  each comprising a plurality of elastic elements attached thereto in their circumferentially tensioned or stretched condition. Second elastic members  14  are provided along lower waist regions  17  disposed downward of the peripheral edge regions  16 . Second elastic members  14 , each also comprising a plurality of elastic elements attached thereto in their circumferentially tensioned or stretched condition, are also provided. The crotch section  8  has a sheet member  15 , which is stretchable in its longitudinal direction, that is joined at its longitudinally opposite ends  8 A,  8 B to lower ends  6 A,  7 A (FIG. 2) of the front and rear sections  6 ,  7 , respectively, immediately above upper ends  10 A of the respective leg-openings  10 , to form a pair of leg-openings  10 . The main body  2  is provided on its inner side with the absorbent pad  3  extending longitudinally in and from the crotch section  8  into a position adjacent to the front and rear sections  6 ,  7 . 
     FIG. 2 is a sectional view taken along line II—II in FIG.  1 . In the main body  2 , each of the front and rear sections  6 ,  7  comprises a topsheet  25  and a backsheet  26 , both made of a nonwoven fabric that are intermittently bonded to an air/moisture permeable plastic film  27  disposed therebetween. The first and second elastic members  13 ,  14  are disposed between the topsheet  25  and the film  27  and are secured to the inner surface of at least one of the topsheet  25  and film  27 . The sheet member  15 , as a component of the crotch section  8 , comprises a topsheet  30  and a backsheet  31 , both made of a nonwoven fabric, and an air/moisture-permeable plastic film  32  which is disposed therebetween and stretchable at least in its longitudinal direction. The topsheet  30  and the backsheet  31  are intermittently bonded to the film  32 . In the main body  2 , the film  27  assures that the front and rear sections  6 ,  7  have a desired tensile strength and the film  32  assures that the crotch section  8  has a desired tensile strength and stretchability. 
     The front and rear sections  6 ,  7  respectively carry on their circumferential middle regions first suspending flaps  20 A,  20 B. These flaps  20 A,  20 B are made of a flexible sheet  35  such as a nonwoven fabric, which is soft and agreeable to touch, or cushiony and spongy material such as a plastic film or polyurethane foamed sheet, or a laminate of the nonwoven fabric and spongy material. The first suspending flaps  20 A,  20 B have their base ends  35 A joined by means of hot melt adhesive  37  to the inner surface of the peripheral edge region  16  of the waist-opening  9  and their free ends  35 B hanging down toward the crotch section  8  to extend into the lower waist region  17 . The free ends  35 B are provided on their surface opposed to the inner surface of the main body  2  with first fastening means  39  comprising one component  36 A of a pair of mechanical tape fasteners  36  such as loop and hook systems, which is available under the trade name of VELCRO, secured thereto by a suitable means (not shown). 
     The pad  3  comprises an absorbent panel  42  which comprises, in turn, a compression-molded mixture  40  of fluff pulp fibers and discrete particles of a water insoluble hydrogel with tissue papers  41  covering it. A topsheet  43  and a backsheet  44  cover upper and lower surfaces of the panel  42 , respectively. Portions of the topsheet  43  and the backsheet  44  extending outward beyond a peripheral edge of the panel  42  are bonded together. With regard to such extensions, portions extending outward beyond longitudinally opposite ends of the panel  42  form a pair of second suspending flaps  18 ,  19  interposed between the front and rear sections  6 ,  7  and the first suspending flaps  20 A,  20 B, respectively. Surfaces of the second suspending flaps  18 ,  19  opposed to the first suspending flaps  20 A,  20 B are provided with second fastening means  51  comprising the other component  36 B of the tape fastener  36  are secured thereto by a suitable means (not shown) and operatively associated with the respective components  36 A of the tape fastener  36  such that components  36 A,  36 B may be releasably engaged together. The pad topsheet  43  is made of a liquid-permeable nonwoven fabric or a plastic film. The pad backsheet  44  is preferably made of a liquid-impermeable plastic film. An extremely thin plastic film covered with a nonwoven fabric to improve its strength as well as the touch of the film may also serve as the backsheet  44 . A liquid-permeable nonwoven fabric may also be used to form the backsheet  44  so long as the panel  42  has a sufficient moisture holding capability. 
     FIG. 3 is an illustration of pants  1  separated along the heat-seal regions  11  into the front and rear sections  6 ,  7  and opened out from the position shown by FIG. 1 in the longitudinal direction as indicated by arrows P, Q in a plan view partially broken away. As shown, the pants  1  are opened also in the transverse direction and the gathers formed in the front and rear sections  6 ,  7  as well as in the crotch section  8  in FIG. 1 disappear as the pants  1  are opened in these two directions. The first suspending flaps  20 A,  20 B are provided adjacent their transversely opposite ends with component  36 A of the tape fastener  36  and the second suspending flaps  18 ,  19  are provided adjacent their transversely opposite ends with the other component  36 B of the tape fastener  36  operatively associated with the component  36 A. The pad  3  is provided along its transversely opposite side edges with longitudinally extending elastic members  50 , respectively, which are disposed between the topsheet  43  and the backsheet  44  and secured in a tensioned or stretched condition to the inner surface of at least one of these two sheets  43 ,  44 . 
     In the pants  1  constructed as described above, the flexible sheet  35  for the first suspending flaps  20 A,  20 B as well as the topsheet  43  and the backsheet  44  of the pad  3  are preferably made of a soft material which is agreeable to touch and does not adversely affect the circumferential stretchability of the front and rear sections  6 ,  7 . For bonding the first suspending flaps  20 A,  20 B to the main body  2  and for bonding the topsheet  43  and the backsheet  44  together, it is preferred to use soft type adhesive or to arrange intermittent bonding spots in consideration that these components should keep their softness. It is also possible to define the second suspending flaps  18 ,  19  by one of the topsheet  43  and the backsheet  44  if it is desired to improve the softness in these flaps  18 ,  19 . As a criterion of softness, the first suspending flaps  20 A,  20 B and the second suspending flaps  18 ,  19  preferably have a stiffness of less than 150 mm as measured according to JIS P 8143. The presence of the tape fasteners components  36 A,  36 B increases the rigidities in the first and second fastening means  39 ,  51  relative to the first and second suspending flaps  20 A,  20 B,  18 ,  19  so that the presence of these first and second fastening means  39 ,  51  can be easily detected by the user&#39;s hand as it touches the first and second suspending flaps  20 A,  20 B,  18 ,  19  owing to the higher rigidities. If the rigidities of the first and second fastening means  39 ,  51  themselves are insufficient, such insufficiency can be compensated for by means of the rigidity of the adhesive used to bond the fastener components  36 A,  36 B to the respective first and second suspending flaps  20 A,  20 B,  18 ,  19 . 
     In order to form the first and second fastening means  39 ,  51 , the tape fastener components  36 A,  36 B may be replaced with pressure-sensitive adhesive. For example, the tape fastener components  36 A or  36 B may be replaced by pressure-sensitive adhesive tape fastener applied to their underlying member at the corresponding regions to form adhesive fastening regions and the other tape fastener components  36 B or  36 A may be replaced with relatively thick plastic film sheets bonded to their underlying members at the corresponding regions so that the adhesive fastening regions may be releasably fastened thereto. Instead of these pressure-sensitive adhesive and plastic film sheets, autohesion-type adhesive may be applied to both the first and second fastening means  39 ,  51  so that the respectively facing pairs of fastening regions coated with this autohesion-type adhesive may be separably bonded together. If the first and second fastening means  39 ,  51  can not obtain the desired rigidity merely by application of the pressure-sensitive adhesive and bonding of the plastic film sheets, nonwoven fabric or plastic film sheets may be additionally laminated on these fastening means. 
     In the inventive disposable absorbent undergarment, the first and second suspending flaps  20 A,  20 B,  18 ,  19  can be reliably fastened together over adequately large areas without being affected by the gathers formed in the elastic peripheral edge regions  16 , since the first and second fastening means  39 ,  51  respectively provided on the first and second suspending flaps  20 A,  20 B,  18 ,  19  are more rigid than the first and second suspending flaps  20 A,  20 B,  18 ,  19  themselves, and extend downward beyond the elastic peripheral edge regions  16 . Furthermore, such rigidity facilitates detection of the presence of these first and second fastening means  39 ,  51  and enables the pad to be smoothly mounted or interchanged. 
     The first fastening regions  39  are provided with their surfaces facing the inner surface of the main body  2  and, in addition, the first suspending flaps  20 A,  20 B are cushiony, so the first fastening means  39  give the wearer neither a feeling of incompatibility nor uncomfortable irritation, in spite of their relatively high rigidity. 
     The longitudinally stretchable crotch section  8  contracts in the longitudinal direction and therefore closely contacts the pad  3  against the wearer&#39;s crotch to prevent body fluid from leaking therefrom.