JP4471769B2 - Pants-type disposable diapers - Google Patents

Description

  The present invention relates to a pants-type disposable diaper, and more particularly to a so-called belly-wrap type pants-type disposable diaper.

  Various proposals for bringing a pants-type disposable diaper into close contact with a wearer's body have been made. For example, at least the ventral side of the diaper is defined between a first waist area defined by a maximum of 20 mm in each of the upper and lower sides with the front end edge of the core as a boundary, and defined between the first waist area and the leg opening. A pants-type disposable diaper having a second waistline area, wherein the arrangement interval dimension of the elastic members in the first waistline area is smaller than the arrangement interval dimension of the elastic members in the second waistline area Has been proposed (see Patent Document 1). In this diaper, the first torso area is more than the second torso area in terms of adhesion to the skin while substantially equalizing the surface pressure per fixed area in the first torso area and the second torso area. By making it good, it is intended to prevent leakage without impairing the feeling of wearing the diaper.

  Also known is a pants-type disposable diaper that has a strong contraction force acting on the upper part of the wearer's torso and lumbar bone by gradually reducing the spacing between the elastic members toward the leg opening. (See Patent Document 2).

  Apart from these diapers, by placing elastic bodies arranged in the direction around the waist of the wearer on the upper and lower parts of the bulge of the abdomen, A pants-type disposable diaper has also been proposed (see Patent Document 3).

  Since the pants-type diapers described in Patent Documents 1 and 2 have a certain level of rise, the diaper is lifted up to cover the vicinity of the wearer's navel. Moreover, in the underpants type diaper described in Patent Literature 3, the vicinity of the wearer's navel is covered with the diaper in a normal wearing state. Although these diapers show a relatively good fit immediately after being worn, the diapers gradually fall off as the wearer moves, and the abdomen is exposed to deteriorate the appearance of the worn state. As a result, the absorption performance is adversely affected, and it cannot be said that “safety” for leakage prevention, which is an important required performance in disposable diapers, is achieved.

Japanese Patent Laid-Open No. 9-84826 Japanese Utility Model Publication No. 6-421 Japanese Patent No. 3084203

  Accordingly, it is an object of the present invention to provide a pants-type disposable diaper that can eliminate the various drawbacks of the above-described prior art.

The present invention is a pants-type disposable diaper in which a trunk opening and a pair of leg openings are formed,
The diaper has an abdominal flap portion and a back flap portion that respectively extend in the front-rear direction from the front and rear end portions of the absorbent core, and the abdominal flap portion and the back flap portion have their edges in the diaper wearing state. Has a length that extends beyond the umbilical point of the wearer and sufficiently covers the abdomen and back of the wearer,
By providing a pants-type disposable diaper provided with means capable of fixing the diaper to a site from the wearer's iliac crest to the upper anterior iliac spine when the diaper is worn. Is achieved.

  The wearing state (appearance) immediately after wearing of the diaper of the present invention is good, and it is difficult for the diaper to fall off due to the movement of the wearer while wearing the diaper. Further, since the abdomen flap and the back flap cover a wide range from the wearer's abdomen to the back, it is very effective in preventing the body from getting cold. This is especially effective for infants who do not have sufficient temperature regulation. Since the abdominal flap and the back flap only tighten the wearer's body loosely, the wearer does not feel uncomfortable. In addition, it is easy to perform the wearing operation.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The perspective view of one Embodiment of the underpants type disposable diaper of this invention is shown by FIG. FIG. 2 is an exploded perspective view showing a state before the diaper shown in FIG. 1 is assembled. FIG. 3 shows a plan view of the developed state of the diaper in FIG. In the following description, the developed state of the diaper refers to a state before the side seal portion of the diaper is joined.

  The diaper 1 of the present embodiment is substantially vertically long having a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid-retaining absorbent core 4 interposed between the two sheets 2 and 3. The absorbent body 10 and the outer packaging material 11 arranged on the back sheet 3 side of the absorbent body 10 are provided.

  The outer packaging material 11 has an hourglass shape in which both side edges are bound inward in the central portion in the longitudinal direction, and defines the outline of the diaper. The outer packaging material 11 is divided in the longitudinal direction into an abdominal side A disposed on the wearer's abdominal side, a back side B disposed on the back side, and a crotch C positioned therebetween. The abdomen A and the back B correspond to the longitudinal front and rear ends of the outer packaging material 11, and the crotch C corresponds to the longitudinal center of the outer packaging material 11. The outer packaging material 11 has both side edges A1 and A2 of the ventral side A and both side edges B1 and B2 of the back side B joined together, and the diaper 1 has a trunk opening 5 and a pair of leg openings 6. It is formed. By this joining, a pair of side seal portions S are formed on the left and right side edges of the diaper 1. For this joining, for example, heat sealing, high frequency sealing, ultrasonic sealing or the like is used.

  The top sheet 2, the back sheet 3, and the absorbent core 4 each have a rectangular shape, and are integrated to form a vertically long absorbent body 10. As the surface sheet 2 and the back surface sheet 3, the same material as that conventionally used for this type of diaper can be used. The absorbent core 4 is made of superabsorbent polymer particles and a fiber material, and is covered with tissue paper (not shown).

  As shown in FIG. 2, side cuffs 8, 8 made of a liquid resistant or liquid impermeable and breathable material are formed on the left and right sides of the absorbent body 10 in the longitudinal direction. Each side cuff 8 has a fixed end and a free end along the longitudinal direction of the absorbent body 10. The fixed end is fixed to the top sheet 2. On the other hand, a side cuff elastic member 81 is arranged in an expanded state in the vicinity of the free end. Thereby, the side cuff 8 stands up and the outflow of the liquid to the width direction of the absorber main body 10 is prevented.

  The outer packaging material 11 has at least two nonwoven fabrics, that is, an outer layer nonwoven fabric 12 and an inner layer nonwoven fabric 13 disposed on the inner surface side of the outer layer nonwoven fabric 12. The outer layer nonwoven fabric 12 forms the outer surface of the diaper 1, and the inner layer nonwoven fabric 13 is joined to the inner surface side of the outer layer nonwoven fabric 12 with an adhesive such as a hot melt pressure-sensitive adhesive.

  The outer packaging material 11 extends from the front and rear end edges of the absorbent body 10 in the front-rear direction, and the extended portions form the abdomen flap portion Fa and the back flap portion Fb. The abdomen flap Fa and the back flap Fb have such a length that their edges extend beyond the umbilical point of the wearer and sufficiently cover the wearer's abdomen and back in the wearing state of the diaper 1. Yes. Thereby, in the wearing state of the diaper 1, the abdominal flap and the back flap cover a wide area from the wearer's belly to the back. As a result, the wearer's body is effectively prevented from cooling. In particular, since an infant may have an underdeveloped body temperature regulation function, it is extremely effective to have the infant wear the diaper 1 of this embodiment. From this viewpoint, the width of the abdomen flap Fa and the back flap Fb (the length of the abdomen flap Fa and the back flap Fb in the longitudinal direction of the diaper 1) is preferably 40 to 100 mm, particularly preferably 50 to 90 mm.

  In the abdomen flap part Fa and the back flap part Fb in the outer packaging material 11, a plurality of flap part elastic members 51, 51 are arranged in the width direction of the outer packaging material 11. The flap elastic members 51 and 51 are sandwiched and fixed in an expanded state by the outer layer nonwoven fabric 12 and the inner layer nonwoven fabric 13. The flap elastic members 51, 51 are connected to the side edges A 1, A 2 of the ventral side A of the diaper 1 and the side edges B 1, B 2 of the back side B to each other. It arrange | positions so that edge parts may overlap. Thereby, as shown in FIG. 1, a substantially continuous ring-shaped gather is formed in the vicinity of the trunk opening 5 of the diaper 1.

  Leg part elastic members 61 a and 61 b are arranged on the left and right curved parts of the outer packaging material 11. Each leg part elastic member 61a, 61b is distribute | arranged along the said curved part. Each leg part elastic member 61a, 61b is arranged between the outer layer nonwoven fabric 12 and the inner layer nonwoven fabric 13, and is fixed to the nonwoven fabrics 12, 13 in a stretched state by a predetermined joining means. One end of each leg portion elastic member 61a, 61b overlaps in the crotch portion C. On the other hand, the other end is terminated at the position of each side edge of the ventral side A and the back side B. When each leg part elastic member 61a, 61b joins both the side edges A1, A2 of the belly side part A of the diaper 1 and both side edges B1, B2 of the back side part B, the both elastic members 61a, 61b It arrange | positions so that edge parts may overlap. Thereby, as shown in FIG. 1, a substantially continuous ring-shaped leg gather is formed in the vicinity of the leg openings 6, 6 of the diaper 1.

  In the diaper 1, a large number of elastic members 71 a extending in the width direction of the diaper 1 are arranged between the abdomen flap portion Fa and the back flap portion Fb and the leg opening 6. By arranging the elastic member 71 a, a region 71 extending in the width direction of the diaper 1 is formed between the trunk opening 5 and the leg opening 6. In the region 71, an elastic member 71a is disposed. The region 71 is located adjacent to the flap portions Fa and Fb between the abdomen flap portion Fa and the back flap portion Fb and the leg opening 6.

  The elastic member 71a is sandwiched and fixed in an expanded state by the outer layer nonwoven fabric 12 and the inner layer nonwoven fabric 13. The elastic member 71a is configured such that when the side edges A1, A2 of the ventral side A of the diaper 1 and the side edges B1, B2 of the back side B are joined to each other, the elastic member 71a of the ventral side A and the back side It arrange | positions so that the edge parts with B elastic member 71a may overlap. As a result, gathers are formed in the region 71 on the ventral side and the back side of the diaper 1. From the viewpoint of preventing penetration of liquid from the outside of the diaper and exudation of liquid from the inside, it is preferable that both of the inner layer nonwoven fabric 13 and the outer layer nonwoven fabric 12 are water-repellent nonwoven fabrics.

  The elastic member 71 a extends between the left and right side edges of the diaper 1 (that is, the left and right side edges of the outer packaging material 11) and the left and right side edges of the absorbent core 4. And the elastic member 71a does not exist substantially in the site | part in which the absorptive core 4 exists. As a result, the gathers formed in the region 71 are located between the left and right side edges of the diaper 1 and the left and right side edges of the absorbent core 4, and the gathers are substantially present at the position where the absorbent core 4 is present. Not formed. As a result, the outer wrapping material 11 does not shrink due to the contraction of the elastic member 71a in the portion where the absorbent core 4 is present even in the mounted state, and the diaper 1 has good appearance and absorption performance. It will be a thing.

  As each elastic member in the diaper 1 of the present embodiment, a stretchable material such as natural rubber, polyurethane resin, urethane foam resin, stretchable nonwoven fabric or hot melt stretchable member is used as a thread (thread rubber) or a strip (flat). (Rubber), net (net) or film is preferably used.

  The diaper 1 of the present embodiment is provided with means capable of fixing the diaper at a site from the wearer's iliac crest to the upper anterior iliac spine when the diaper 1 is worn. The means employed in the present embodiment as the means is the elastic member 71a arranged in the region 71 described above. The region 71 is preferably formed at a portion that abuts a portion (hereinafter also referred to as an iliac region) from the wearer's iliac crest to the upper anterior iliac spine when the diaper 1 is worn. The iliac crest and superior anterior iliac spine are anatomical terms. The iliac crest is a part indicated by 9a in FIG. 4, and the superior anterior iliac spine is a part indicated by 9b in FIG. Conventionally, in order to prevent slippage during wearing of a pants-type diaper, particularly in order to prevent slippage during wearing of a pants-type disposable diaper for infants, tightening of an elastic member disposed in the trunk opening It has been considered effective to increase the pressure so that the pants-type diaper is brought into close contact with the wearer's body through the trunk opening (for example, see Patent Document 2 described above). However, as a result of the study by the present inventors, in order to effectively prevent slippage during wearing of the pants-type diaper, the tightening pressure of the trunk opening, that is, the abdominal flap Fa and the back flap Fb in the present embodiment. It has been found that it is more effective to increase the tightening pressure of the region 71, which is the diaper region corresponding to the wearer's iliac region, than to increase the tightening pressure of the site to be formed. The reason for this is that wearers, particularly infants, have their belly bulging as a physical feature, so if the tightening pressure at the trunk opening that abuts against the bulging belly is high, the tightening pressure is high. This is because the trunk opening is gradually narrowed down, and the trunk opening is shifted down to a site where the belly circumference becomes narrow.

FIG. 5 shows a state in which the baby's body is regarded as a cone. In the figure, θ represents an angle formed by a perpendicular to the tangent line at the waist (point A) and a horizontal line toward the center of the body, F represents a tightening force of the elastic body, P represents a frictional force caused by F, f1 indicates a slip-off force caused by F, and f2 indicates a vertical drag. Here, since f1 = Fsinθ and P = νN = νf2 = νFcosθ (ν represents a friction coefficient), the downward slipping force Z at the point A is represented by the following equation.
Z = f1−P = Fsinθ−νFcosθ = F (sinθ−νcosθ)
From this equation, it can be understood that when the waist portion is in a state where slipping occurs, the slipping force increases as the tightening force (F) increases.

  The pressure when the diaper 1 is worn in the region 71 is preferably 1.1 to 2.5 kPa. Accordingly, the region 71 can be successfully fixed to the wearer's iliac region without excessively tightening the wearer's body, and the diaper 1 can be effectively prevented from falling off. From the viewpoint of more effectively preventing the diaper 1 from falling off and further improving the appearance of the diaper 1 and the wearing operation of the diaper 1 in the wearing state, the pressure when the diaper 1 is worn in the region 71 is 1.1 to 1. The pressure is more preferably 2.0 kPa, and still more preferably 1.2 to 1.8 kPa. This pressure is a value measured in the region 71 where the elastic member 71a is disposed.

  The pressure at the time of wearing of the diaper 1 in the region 71 can be controlled, for example, by adjusting the thickness or elongation rate of the elastic member 71a or the arrangement interval.

  The pressure when the diaper 1 is worn in the region 71 is measured by a wearing pressure measuring device (a contact pressure measuring device (AMI3037-2) manufactured by AIM Techno Co., Ltd.) mounted on a cylinder having a circumference of 500 mm. Is done. The specific measurement method is as follows.

[Method of measuring pressure in region 71]
Using an air pack of φ = 15 mm, the air pack is set so that the center of the air pack is positioned at the front end position of the trunk opening on the abdominal side, and the mounting pressure (P1) is measured. The position of the diaper width direction in which the air pack is set is approximately the center between the left and right side edges of the diaper and the left and right side edges of the absorbent core 4 (see FIG. 3). Subsequently, the center of the 5 mm air pack is moved in the length direction of the diaper 1 to measure the mounting pressure (P2). Similarly, measurement is performed at intervals of 5 mm to obtain P3, P4, P5,. The measurement of P1 to Pn is performed over a range in which the left and right side portions from the trunk opening to the leg opening in the outer packaging material 11 are joined to each other. For P1 to Pn, a total of four points are measured on the ventral side, two on each side. These average values are taken as the pressure on the ventral region. Similarly, a total of four points are measured on the back side, and the average value is set as the mounting pressure on the back side. The distance between the portions corresponding to 1.1 to 2.5 kPa continuously in the values of P1 to Pn is defined as the width of the region 71. For example, when P3 to P6 are applicable, the width of the region = (6-3) × 5 = 15 mm. The center of the region 71 at that time is the midpoint between the measurement point 3 and the measurement point 6.

  The part from the wearer's iliac crest to the upper anterior iliac spine has a certain width, and the region 71 is fixed to the part within the range of the width, thereby effectively preventing the diaper 1 from falling off. can do. From this viewpoint, in the diaper 1 of the present embodiment, the width W of the region 71 (that is, the length of the region 71 along the longitudinal direction of the diaper 1) is preferably 15 to 35 mm. When this width is 20 to 35 mm, particularly 25 to 30 mm, the diaper 1 can be prevented from slipping off more effectively, and the appearance of the diaper 1 in the wearing state and the wearing operation of the diaper 1 (easy to cut) Etc.) can be further improved.

  In a state where the diaper 1 is worn, the relationship between the size of the diaper 1 and the physique of the wearer is important in order for the region 71 to come into contact with the site from the wearer's iliac crest to the upper anterior iliac spine. It is. For example, when an infant who is a main wear target person of a pants-type diaper is considered, in the unfolded state of the diaper 1, the center position of the region 71 of the ventral side A (center position along the longitudinal direction of the diaper 1) and the length of the diaper 1. The distance K1 between the direction center line CL is 180 to 220 mm, and the center position (center position along the longitudinal direction of the diaper 1) of the region 71 of the back side B and the longitudinal direction of the diaper 1 when the diaper 1 is unfolded By setting the distance K2 to the center line CL to be 180 to 220 mm, the region 71 can be successfully brought into contact with the wearer's iliac region. This value is determined by carrying out body measurements of about 350 infants who are the main wearees of pants diapers. Specifically, as shown in FIG. 6, the abdominal side left-right center point at the horizontal position height of the upper anterior iliac spine is the upper anterior iliac spine anterior center, and the dorsal side is the upper anterior iliac spine posterior center. Then, the length from the center of the superior anterior iliac spine to the center of the posterior segment of the superior anterior iliac spine via the crotch is defined as the height of the superior anterior iliac spine. The numerical value obtained by adding the required length in consideration of the thickness and the like is divided into two. By setting the distances K1 and K2 to 185 to 215 mm, particularly 185 to 210 mm, the region 71 can be brought into more successful contact with the wearer's iliac region.

  Although the region 71 exists in the ventral part A and the dorsal part B, the pressure at the time of wearing in the ventral part A and the dorsal part B does not have to be exactly the same. That is, if the pressure at the time of mounting of the region 71 in the ventral side A and the back side B is 1.1 to 2.5 kPa, the elastic material, thickness, elongation rate, and disposition interval are The side A and the back B may be different. However, if the configurations of the regions 71 of the ventral portion A and the dorsal portion B are excessively different, the portions where the left and right side portions of the longitudinal front and rear end portions of the outer packaging material 11 are joined to each other may be The diaper 1 may be out of order, and the appearance of the diaper 1 may be defective. Therefore, the ratio of (A−B) / A is within 30% when the larger pressure at the time of wearing the region 71 in the ventral portion A and the dorsal portion B is A and the smaller pressure is B. preferable.

  In the present invention, the longitudinal center line CL of the diaper 1 is joined to the side edges A1, A2 of the ventral side A of the diaper 1 and the side edges B1, B2 of the back side B without substantially shifting. In this case, it means a straight line along the diaper width direction passing through the midpoints of A1 and B1 in the unfolded state of the diaper 1 (see FIG. 3). Unlike this, for example, as shown in FIGS. 7A and 7B, both side edges A1, A2 of the ventral side A are not joined to both side edges B1 ′, B2 ′ of the back side B, In the case of joining at B1 and B2 which are positions inward in the longitudinal direction from both side edges B1 ′ and B2 ′, assuming that there is no region from B1 and B2 to B1 ′ and B2 ′, As before, a longitudinal centerline of the diaper is defined.

  In addition, the total length L of the outer packaging material 11 in the unfolded state of the diaper 1 can be arbitrarily set, but is set to 490 to 610 mm in consideration of “safety” and “prevention of slipping” when the diaper is mounted and after use. It is preferable to do.

  As described above, in the diaper 1 according to the present embodiment, the diaper 1 is fixed to the wearer's body mainly by the tightening force of the elastic member 71a disposed in the region 71. In other words, the tightening force by the elastic member 51 disposed on the abdomen flap portion Fa and the back flap portion Fb is not the main means for fixing the diaper 1 to the wearer's body in the diaper 1 of the present embodiment. . On the other hand, it has been confirmed by the present inventors that if the tightening force of the elastic member 51 is increased, the diaper 1 will be displaced. From this viewpoint, in the diaper 1 of this embodiment, it is preferable that the pressure of the abdominal flap part Fa and the back flap part Fb when wearing the diaper is 0.2 to 1.5 kPa. This pressure is preferably lower than the pressure in the region 71 when the diaper is worn. In addition, by setting the pressure of the abdomen flap portion Fa and the back flap portion Fb when wearing the diaper within the above range, the trunk opening 5 can be easily expanded when the diaper 1 is worn, and the wearing operation can be easily performed. There is also. In particular, in the diaper 1 of the present embodiment, since the depth of the trunk opening 5 is deeper than that of a conventional pant-type diaper, if the tightening pressure at that portion is high, the mounting operation becomes very difficult, Such inconvenience can be avoided by setting the pressures of the abdomen flap part Fa and the back flap part Fb within the above-mentioned range. When the pressure of the abdomen flap part Fa and the back flap part Fb when wearing a diaper is 0.2 kPa or less, the natural length of the diaper 1 before wearing becomes large, and it looks bad when viewed as clothes. May occur.

  When the pressure of the abdomen flap part Fa and the back flap part Fb when wearing a diaper is more preferably 0.3 to 1.2 kPa, and more preferably 0.3 to 1.0 kPa, the diaper 1 may be displaced. This can be prevented more effectively. The pressure in the abdomen flap part Fa and the back flap part Fb can be measured by the same method as the pressure in the region 71 described above. That is, a cylinder having a circumferential length of 500 mm is inserted (mounted) into the trunk opening 5 of the diaper 1 and the mounting pressure (P1) is measured. The position of the diaper width direction in which the air pack is set is approximately the center between the left and right side edges of the diaper and the left and right side edges of the absorbent core 4. Subsequently, the center of the 5 mm air pack is moved in the diaper length direction, and the mounting pressure (P2) is measured. Similarly, measurement is performed at intervals of 5 mm to obtain P3, P4, P5,. P1 to Pm are measured up to the upper end of the region 71 in the diaper longitudinal direction. For P1 to Pm, a total of four points are measured on the ventral side, two on the left and right sides, and the average value is used as the pressure on the ventral side. Similarly, a total of four points are measured at the back side, and the average value is set as the wearing pressure at the back side. The pressures of the abdomen flap portion Fa and the back flap portion Fb can be controlled by adjusting the thickness, elongation rate, or arrangement interval of the elastic member 51, for example.

  When the tightening pressure of the abdomen flap part Fa and the back flap part Fb is lowered, the rigidity of these flap parts is reduced due to this, and the flap part is wrinkled, slackened, bent, and the appearance of the diaper 1 in the worn state May be damaged. Further, when the rigidity of the abdomen flap part Fa and the back flap part Fb is reduced, the diaper is displaced, particularly, the abdomen center part is displaced. Therefore, in the diaper 1 of the present embodiment, the rigidity in the vertical direction of these flap portions (that is, the vertical direction of the diaper 1) is 10 to 40 N / m, preferably 12 to 35 N / m, and more preferably 15 to 35 N / m. Nonetheless, such inconvenience is avoided. In this case, the abdomen flap part Fa and the back flap part Fb may have the same or different rigidity.

  The longitudinal rigidity of the abdomen flap part Fa and the back flap part Fb is measured by the following method. A sample (longitudinal direction 30 mm × horizontal direction 50 mm) is cut out from the diaper 1 from substantially the center in the width direction of the abdomen flap portion Fa and the back flap portion Fb. A sample is put in a Tensilon universal testing machine with a chuck distance of 20 mm, and the maximum load when compressed in the vertical direction at a speed of 10 mm / min is measured. The load value is divided by the lateral width (50 mm). The measurement is performed on at least 6 samples, and the average value is used as the stiffness value.

  Furthermore, in the diaper 1 of this embodiment, it is preferable that the pressure of the leg opening 6 at the time of wearing the diaper is 1.0 to 2.4 kPa, particularly 1.2 to 2.2 kPa. When the pressure of the leg opening 6 at the time of wearing the diaper is within the above range, the opening end of the leg opening 6 fits the wearer's buttocks appropriately, and the liquid leakage from around the leg of the wearer is effective. Can be prevented. Further, even when the weight of the diaper's crotch increases due to urination / defecation during use, the absorber is prevented from separating from the wearer's body in the crotch, and the appearance of the diaper 1 being worn is reduced and urine and Stool leakage is prevented. As a result, effects such as being able to keep the diaper 1 in a worn state in a good state can be obtained.

  The mounting pressure at the leg opening is measured by the following method. The device / air pack is the same as the waist opening measurement. A cylinder having a circumferential length of 300 mm is inserted into (attached to) the leg opening 6 of the diaper 1, and six points are measured at intervals of 50 mm in the circumferential direction at the portion where the elastic members 61 a and 61 b are arranged. When there are a plurality of elastic members 61a and 61b, measurement is performed at the center point of the width of the region where the elastic members are arranged. The average value of 12 points on the right foot and left foot is taken as the mounting pressure of the leg opening 6. For those where the leg elastic members 61a and 61b are not completely or partially, the mounting pressure in the region where the side cuff elastic members 81 are disposed in the corresponding portion is used as the mounting pressure of the leg opening. The reason why the circumference of the cylinder is 300 mm is that the average length of the buttocks (foot circumference) of the infant who is the main subject wearing the diaper 1 of the present embodiment is approximately 300 mm.

  The present invention is not limited to the embodiment. For example, in the above-described embodiment, the elastic member 71a disposed in the region 71 is used as a means for fixing the diaper 1 to the wearer's iliac region when the diaper 1 is worn. In the wearing state of the diaper 1, the abdomen side part and the back side part of the material 11 are in contact with the wearer's skin in the wearing state of the diaper 1, and a means for increasing the frictional force is applied. May be. Examples of the means for increasing the frictional force include a sheet, a film, a nonwoven fabric, and the like using a polyolefin-based, styrene-based, or polyurethane-based elastomer bonded to the inner surface of the diaper (diaper skin facing surface). Further, an adhesive such as hot melt may be applied to the inner surface of the diaper. In consideration of preventing the diaper from falling off, the coefficient of friction with the skin is preferably 0.8 or more in the means for increasing the frictional force. When the coefficient of friction with the skin is large, a large frictional force can be obtained even with a small tightening force. As a result, it is possible to reduce an effect that the trace of the elastic member is left on the skin by wearing, or to obtain an additional effect such as improvement in ease.

  Instead of the means for increasing the frictional force, the diaper 1 corresponding to the iliac region so that the mounting pressure of the wearer's iliac region is within the above range (1.1 to 2.5 kPa) after the diaper is mounted. These parts may be tightened with a belt or the like. Or even if it is a site | part which does not contact | abut to a wearer's iliac area | region at the time of mounting | wearing of the diaper 1, mounting | wearing pressure is applied to the site | part which contact | abuts to a wearer's iliac area | region as a result of position shift of the diaper 1 during wear. An elastic member may be arranged so as to be within the above range.

  Moreover, in the diaper 1 of the said embodiment, although the elastic member 71a is distribute | arranged only between the right-and-left both-sides edge of the diaper 1, and the left-right both-sides edge of the absorptive core 4, it is not limited to this structure, A part of the elastic member 71a can be overlapped only on the left and right side edges of the absorbent core 4, or can be arranged over the entire length of the diaper in the width direction. In this case, a force for contraction by the elastic member 71 a acts on the outer packaging material 11 in a portion overlapping the absorbent core 4. However, even in such a case, the outer packaging material 11 located in the region where the absorbent core 4 is disposed is attached to the absorbent core 4 with an adhesive, so that the elasticity of the elastic member can be obtained using the rigidity of the core 4. Shrinkage can be suppressed and wrinkles can be prevented from occurring in the outer packaging material 11 in the portion where the core 4 is disposed. Further, the core 4 is also arranged by not allowing the elastic member 71a sandwiched and fixed between the outer layer and the inner layer nonwoven fabrics 12 and 13 to be almost fixed to the nonwoven fabrics 12 and 13 only in the portion where the absorbent core 4 is arranged. It is also possible to prevent wrinkles from occurring in the outer packaging material 11 in the portion.

  As shown in FIG. 8, the abdomen flap part Fa and the back flap part Fb use two or more kinds of elastic members 51a and 51b having different elongation rates, materials, thicknesses, arrangement intervals, and the like at the time of joining and fixing. May be.

9, in the region 71 of the ventral side A, the elastic member 71a is arranged over the entire width direction of the diaper, and the central portion of the elastic member 71a is projected toward the crotch C of the diaper. It may be curved into a shape.
With such a curved shape of the elastic member 71a, when the diaper 1 is worn, the pressing force of the elastic member 71a stably acts on the wearer's belly. In particular, the diaper can be more easily fitted to the infant's body shape with the abdomen around. As a result, the vertical displacement of the diaper is less likely to occur.

  Further, as shown in FIG. 10, a plurality of elastic members 71a are arranged in the region 71 of the ventral side A over the entire width direction of the diaper, and several elastic members 71a are located near the crotch C of the diaper. May be curved convexly toward the crotch C. In this case, it is preferable to increase the degree of curvature of the elastic member 71a closer to the crotch C. With such an arrangement of the elastic member 71a, a wide range around the abdomen can be covered with the elastic member 71a. As a result, in addition to the contraction in the left-right direction, a force of contraction in the up-down direction is generated, so that it is possible to prevent the diaper from being displaced in the up-down direction and raise the center part of the diaper in the width direction upward. .

  In the outer packaging material 11, only one of the inner layer nonwoven fabric 13 and the outer layer nonwoven fabric 12 can be a water repellent nonwoven fabric. In addition, when the side cuff 8 can ensure sufficient leak-proof property, a water-permeable nonwoven fabric can be used for both the inner layer nonwoven fabric 13 and the outer layer nonwoven fabric 12.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1 and Comparative Examples 1 and 2]
The underpants type diaper shown in FIGS. 1 to 3 was produced. The surface sheet 2 in the absorbent body 10 is composed of a hydrophilic air-through nonwoven fabric having a basis weight of 25 g / m ² . The back sheet 3 is made of a polyethylene sheet having a basis weight of 20 g / m ² . The outer layer nonwoven fabric 11 in the outer packaging material 11 is composed of a water repellent air-through nonwoven fabric having a basis weight of 25 g / m ² , and the inner layer nonwoven fabric is composed of a water repellent spunbond nonwoven fabric having a basis weight of 18 g / m ² . The pressure generated by each elastic member was adjusted by changing the type of elastic material and the elongation rate. Table 1 shows each value in the obtained diaper.

The obtained diapers were attached to three 1 to 2 year old infants and evaluated as follows. The results are shown in Table 1.
(1) Appearance when worn (Reassurance)
○: There is a sense of security △: Slightly safe ×: There is anxiety (2) Misalignment of the diaper after 60 minutes ○: No misalignment △: There is a slight misalignment ×: There is a misalignment (3) Occurrence of sagging and sagging in diapers ○: None △: Slightly present ×: Present

  As is apparent from the results shown in Table 1, it can be seen that the diaper of Example 1 has a good appearance when worn and gives the user a sense of security. The diaper of Example 2 has low rigidity in the flaps of the abdomen and the back, and the diaper position shift and diaper folds / sagging are slightly caused, but at a level with no problem. The diaper of Comparative Example 1 is inferior in safety because the tip positions of the abdominal flap part and the back flap part are below the umbilic point. In addition, there is no effect of preventing chilling. Since the diaper of Comparative Example 2 did not include a means for fixing the diaper in the wearer's iliac region, a displacement occurred.

It is a perspective view which shows one Embodiment of the underpants type disposable diaper of this invention. It is a disassembled perspective view which shows the state before assembling the diaper shown in FIG. It is a top view which shows the expansion | deployment state of the outer packaging material in FIG. It is explanatory drawing which shows an iliac bone. It is explanatory drawing which shows the calculation method of the slipping-off force in a wearer's waist part. It is explanatory drawing which shows the measuring method of upper anterior iliac spine height front and back length. Fig.7 (a) is a perspective view which shows another embodiment of the diaper of this invention, FIG.7 (b) is a top view which shows the unfolded state of the diaper shown in Fig.7 (a). It is a top view in the unfolded state which shows another embodiment of the diaper of this invention. It is a top view in the unfolded state which shows another embodiment of the diaper of this invention. It is a top view in the unfolded state which shows another embodiment of the diaper of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent core 5 Trunk opening 6 Leg opening Fa Abdominal flap Fb Back flap

Claims (8)

A pants-type disposable diaper in which a trunk opening and a pair of leg openings are formed,
The diaper has an abdominal flap portion and a back flap portion that respectively extend in the front-rear direction from the front and rear end portions of the absorbent core, and the abdominal flap portion and the back flap portion have their edges in the diaper wearing state. Has a length that extends beyond the umbilical point of the wearer and sufficiently covers the abdomen and back of the wearer,
An elastic member extending in the width direction of the diaper is disposed on each of the ventral side portion and the dorsal side portion of the diaper at a portion that comes into contact with a portion from the wearer's iliac crest to the upper anterior iliac spine in the wearing state of the diaper. Has been
In the part where the elastic member is arranged, the pressure when wearing the diaper is 1.1 to 2.5 kPa,
In the abdomen flap part and the back flap part, the pressure when the diaper is worn in a part other than the part where the elastic member is arranged is lower than the pressure of the part where the elastic member is arranged, and the pressure A pants-type disposable diaper that is 0.2 to 1.5 kPa .   The pants-type disposable diaper according to claim 1, wherein each of the abdomen flap part and the back flap part has a longitudinal rigidity of 10 to 40 N / m. In the wearing state of the diaper, the elastic member is arranged over the entire region in the width direction of the diaper at the portion that contacts the portion from the wearer's iliac crest to the upper anterior iliac spine, and the central portion of the elastic member is The pants-type disposable diaper according to claim 1, wherein the pant-type disposable diaper is curved in a convex shape toward the crotch part C of the diaper . In the diaper wearing state, a plurality of the elastic members are arranged over the entire width direction of the diaper at a part that abuts on the part from the wearer's iliac crest to the upper anterior iliac spine, and closer to the crotch part of the diaper The pants-type disposable diaper according to claim 1, wherein several elastic members positioned in a convex shape are curved in a convex shape toward the crotch part, and the degree of the curvature is increased as the elastic member is closer to the crotch part . Wherein a portion where the elastic member is disposed pants-type disposable diaper according to claim 1, wherein the width of and the site extends in the width direction of the diaper is 15 to 35 mm. In the deployed state of the diaper, the distance between the longitudinal center line and the center position of the part on the ventral side is 180 to 220 mm, and the center position of the part on the dorsal side from the longitudinal center line The underpants-type disposable diaper according to any one of claims 1 to 5, wherein a distance between them is 180 to 220 mm. It said elastic member sites are arranged, pants type disposable diaper according to claim 1, wherein are present primarily between the left and right side edges of the diaper and left and right side edges of the absorbent core.   Each of the abdomen and dorsal side of the diaper is in contact with the wearer's skin at a site that contacts the site from the wearer's iliac crest to the upper anterior iliac spine in the wearing state of the diaper, The pants-type disposable diaper according to claim 1 or 2, wherein means for increasing the frictional force is applied.

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