JP4519022B2 - Pants-type disposable diapers - Google Patents

Description

  The present invention relates to a pants-type disposable diaper, and more particularly to a pants-type disposable diaper for infants.

  Conventional pants-type disposable diapers have a large crotch in the worn state and often have a rough appearance. As a result, the foot is difficult to move, and the diaper is likely to be displaced due to the movement. A diaper misalignment can lead to leakage. In addition, if the crotch is loose, it becomes difficult to put on overpants or pants on the diaper, and the appearance of the overcoat is not good. If a diaper misalignment occurs due to bumps in the crotch, the bumps are further promoted.

  Therefore, various techniques for narrowing the width of the crotch part of the diaper have been proposed (see Patent Documents 1 to 3). However, when the width of the crotch portion is narrowed, the crotch portion becomes a long and slender shape when worn, and the bumpiness becomes more noticeable. In addition, the ease of movement and the wearability of outerwear such as overpants and trousers are not improved. The same applies to the appearance when worn. In particular, the diaper described in Patent Document 1 narrows the width of the crotch part, and at the same time shortens the length of the side seal part relative to the total length of the diaper, that is, lengthens the non-joint part (= crotch part). It is further promoted that the part hangs down long and narrow.

  In addition to the technique for narrowing the width of the crotch, a technique for preventing the diaper from being displaced has also been proposed. 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 4). 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 5).

  However, these diapers are not of a shape that sufficiently corresponds to the wearer's body shape and skeleton, so that the diaper may fall off during wearing and the appearance may deteriorate, and the wearer may be difficult to move due to the slipping off. There is. Moreover, since a strong tightening pressure is applied to the waist opening, there is a possibility that it is difficult to wear the diaper.

JP 2002-159529 A Japanese Utility Model Publication No. 2-84623 JP-A-11-188056 Japanese Patent Laid-Open No. 9-84826 Japanese Utility Model Publication No. 6-421

  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 waist opening and a pair of leg openings are formed,
In the unfolded state of the diaper, the distance between the lower end edge of the flap portion on the front side in the longitudinal direction and the lower end edge of the flap portion on the rear side portion is set to 210 to 280 mm and The said objective is achieved by providing the underpants type disposable diaper which made the width | variety of a small width part 50-160 mm.

  The pants-type disposable diaper of the present invention has a crotch lower part that is not worn, and the appearance of the diaper is clean. Therefore, the movement of the wearer, in particular, the movement of the foot is not hindered, and the diaper slippage due to the wearer's movement or the like is difficult to occur during wearing of the diaper. As a result, it is difficult for urine and feces to leak. In addition, it is easy to put overpants such as overpants and trousers on the diaper, and the outer appearance of the pants after they are put on is also clean.

  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.

First, a novel design technique that is the basis for completing the present invention will be briefly described with an example.
First step: A sheet (cloth having a sufficient size compared to the planar shape of the absorbent article) is directly applied to the body of a monitor (such as an infant) to perform draping. On the sheeting, write the waist circumference of the monitor, the circumference of the thigh along the thigh root (the thigh root circumference in FIG. 5), each side line and the folded dart. At this time, the right body is accurately collected. A pattern obtained by expanding the sheeting is taken into the CAD, and a pattern obtained by copying the pattern so as to be bilaterally symmetric is used as a base pattern for a planar shape design. 4 (a) to 4 (c) show the base pattern obtained in this way, and the vertical line segment La in the figure is the front and back length of the monitor (from the front center of the waist line through the inseam and the waist The distance to the center behind the line (see FIG. 5) indicates the crotch position (the position in the front-rear direction where the distance between the lines around the left and right thigh roots is the minimum, the monitor ) And the crotch length. A curve Lc indicates a line around the thigh root, a curve Ld indicates a line around the waist, and a curve Le indicates a line on the side of the monitor (ridge on the left and right sides of the monitor). In this way, a base pattern for a plurality of monitors is obtained.

  Second step: The base pattern is divided into a plurality of groups according to the age (month) of the monitor, gender, etc., and averaged for each division to obtain a master pattern. At this time, as for the dimensions of the waist circumference, the front and back length of the crotch, the sides, and the thigh root circumference, the average shape for each section of the dimensions obtained by carrying out body measurements of about 350 infants, the line shape around the thigh root The crotch position, crotch length, dart position, number, and size were obtained by averaging the base patterns for each section. FIG. 4D shows the master pattern thus obtained. All the base patterns can be averaged together and used as a master pattern.

  Third step: The monitor is allowed to act freely, and the behavior is recorded on a video and observed. The actions frequently performed by the monitor and how the wearer's skin expands and contracts during these actions is determined. As a result of observing and analyzing the behavior of infants, infants aged using pants-type absorbent articles (especially pants-type diapers) lean forward and lean from standing to sitting or vice-versa. It was found that the skin on the back side of the thigh root frequently expands and contracts in these operations.

  Fourth step: Modifications that reflect the knowledge of skin expansion and contraction obtained in the third step are added to each master pattern (or a single master pattern) obtained in the second step. This correction is performed in order to secure an area that can follow the expansion and contraction of the skin. FIG.4 (e) is obtained by adding the area | region which attached | subjected the lattice pattern to the master pattern in order to ensure the area | region for tracking the expansion-contraction of the skin of a wearer's thigh root back side in a disposable absorbent article. The corrected master pattern is shown.

  Fifth step: A correction is applied to the correction master pattern to impart ease of wearing (ease of wearing). FIG. 4F is a diagram illustrating a pattern obtained by enlarging the corrected master pattern at a predetermined magnification in the width direction. The pattern obtained by this correction is the final pattern that becomes the planar shape of the diaper. Since the pattern obtained in this way is collected directly from the infant's body shape, it can be said that the pattern has a very high fit to the body shape.

  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 abdominal side portion A and the back side portion B correspond to the longitudinal front side portion and the rear side portion of the outer packaging material 11, and the crotch portion C corresponds to the longitudinal central portion of the outer packaging material 11. A flap portion F extending in the left-right direction is formed on each of the front side portion and the rear side portion in the longitudinal direction of the outer packaging material 11. In the outer packaging material 11, both side edges A1, A2 of the flap part F on the abdominal side A and both side edges B1, B2 of the flap part F on the back side B are joined to each other, and a waist opening is formed in the diaper 1. 5 and a pair of leg openings 6 are 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.

  Each of the top sheet 2 and the back sheet 3 has a rectangular shape, and these and the absorbent core 4 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. Details of the absorbent core 4 will be described later.

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. 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 outer packaging material 11 extends outward from the front and rear end edges of the absorbent body 10, and the extended portion is folded back to the absorbent body 10 side. The wrapped outer packaging material 11 covers the front and rear end portions of the absorber body 10 (that is, the top sheet 2 at the front and rear end portions of the absorber body 10).

  A plurality of waist elastic members 51, 51 are arranged along the width direction of the front and rear end portions of the outer packaging material 11 along the front and rear end edges. The waist 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 waist elastic members 51, 51 are formed on the elastic members 51, 51 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. It arrange | positions so that edge parts may overlap. As a result, as shown in FIG. 1, a substantially continuous ring-shaped waist gather is formed in the vicinity of the waist 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 part elastic member 61a, 61b overlaps in the crotch part 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 extending in the width direction of the diaper 1 are arranged between the waist opening 5 and the leg opening 6 in the stomach side A and the back side B of the diaper 1. By arranging the elastic member, a first region 71 and a second region 72 extending in the width direction of the diaper 1 are formed between the waist opening 5 and the leg opening 6. A first elastic member 71 a is disposed in the first region 71, and a second elastic member 72 a is disposed in the second region 72. The first region 71 is located between the waist opening 5 and the leg opening 6, and the second region 72 is located between the first region 71 and the leg opening.

  Both the first elastic member 71a and the second elastic member 72a are sandwiched and fixed between the outer nonwoven fabric 12 and the inner nonwoven fabric 13 in an expanded state. The first elastic member 71a is a first elastic member 71a of the ventral side A 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 together. And the first elastic member 71a of the back side portion B are arranged so as to overlap each other. The same applies to the second elastic member 72a. As a result, as shown in FIG. 1, gathers are formed in the first region 71 and the second region 72 in the ventral side A and the back side (not shown) of the diaper 1, respectively.

  Both the first elastic member 71 a and the second elastic member 72 a extend 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. Yes. And in the site | part in which the absorptive core 4 exists, neither the 1st elastic member 71a and the 2nd elastic member 72a exist substantially. As a result, the gathers formed in the first region 71 and the second region 72 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 absorbent core 4 is present. The position is substantially free of gathers. Thereby, the part in which the absorbent core 4 is present even in the worn state does not shrink the outer packaging material 11 due to the contraction of the first elastic member 71a and the second elastic member 72a, and the diaper 1 is also visually improved. Also, the absorption performance is good. However, the present invention is not limited to this configuration, and the first elastic member 71a and the second elastic member 72a may be disposed over substantially the entire circumference in the width direction of the diaper 1.

  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.

  In the present embodiment, as shown in FIG. 3, in the unfolded state of the diaper 1, the distance M between the lower end edge of the flap portion F on the front side in the longitudinal direction and the lower end edge of the flap portion F on the rear side portion is set. 210 to 280 mm (hereinafter, this distance is referred to as a distance between the lower ends). The value of the distance between the lower ends M is a numerical value obtained by adding the necessary length in consideration of the thickness of the diaper and the like to the distance between the lower ends of the final pattern obtained from the design method described above. That is, the distance M between the lower ends is a value optimized with respect to the wearer's body shape, and is characterized by a value shorter than the distance between the lower ends in the conventional pants-type diaper. The distance M between the lower ends is a scale representing the length or area of the portion located in the crotch portion of the wearer in the pants-type diaper. Specifically, in a pant-type diaper having a long distance between the lower ends M, the length of the portion located in the crotch portion of the wearer is long or the area is widened, and in a diaper having a short distance between the lower ends M, the opposite is true. And in the diaper 1 of this embodiment, as a result of optimizing the distance M between the lower ends with respect to the wearer's body shape, the distance M is shortened as compared with the conventional pants-type diaper. The length of the part located in a person's crotch part is shorter than before, or the area is made narrower than before. As a result, the portion of the absorbent core 4 of the diaper 1 that is present in the crotch portion of the wearer is reduced, and the crotch portion C of the diaper 1 is less prone to squeeze, so that the appearance of the diaper 1 is clean. For this reason, the wearer's movement, particularly the movement of the foot, is hardly disturbed. Moreover, it is difficult for the diaper to fall off due to the movement of the wearer during wearing of the diaper. As a result, it is difficult for urine and feces to leak. In addition, it is easy to put overpants and trousers on top of the diaper, and the outer appearance of the pants after they are put on will be clean.

  From the viewpoint of making the appearance of the crotch part C of the diaper 1 clearer, the distance M between the lower ends of the diaper 1 is preferably 230 to 270 mm, particularly preferably 230 to 260 mm.

  In addition, although the full length L of the outer packaging material 11 in the unfolded state of the diaper 1 can be arbitrarily set, it is set to 460 to 520 mm in consideration of “clean feeling” and “prevention of slipping” when the diaper is mounted and after use. It is preferable to do. In addition, in consideration of “relief at the time of wearing”, it is desirable to completely cover the navel, and from this point of view, it is preferable to set it to 490 to 580 mm.

  In order to improve the appearance of the diaper crotch C by having an appropriate amount (length or area) of the absorbent core 4 in the crotch of the wearer, not only the distance M between the lower ends but also the diaper crotch C The dimension in the width direction is also important. If the size of the diaper crotch part C is too large, the crotch part C will not fit properly to the wearer's crotch part, resulting in looseness. From this point of view, in the present embodiment, the width of the minimum width portion of the diaper crotch lower portion C, that is, the width N (see FIG. 3) of the minimum width portion in the center portion in the longitudinal direction of the unwrapped outer packaging material 11 is set to 50 to 160 mm. It is set. When the minimum width portion is not fixed at one place and the minimum width portion has the same width and extends in the longitudinal direction, the position of the same width portion in the longitudinal direction is defined as the minimum width portion.

  The width N of the minimum width portion is characterized by being shorter than a conventional pants-type diaper. That is, in the diaper 1 of this embodiment, the dimension of the absorptive core 4 which exists in a wearer's crotch part becomes short compared with the conventional pants type diaper in any of the longitudinal direction and the width direction. Yes. From the viewpoint of further improving the appearance of the diaper crotch portion C, the width N of the minimum width portion is preferably 60 to 140 mm, particularly preferably 60 to 120 mm.

  As described above, in the diaper 1 of the present embodiment, the size of the absorbent core 4 existing in the crotch portion of the wearer is small in both the longitudinal direction and the width direction. That is, the amount of the absorbent core 4 present in the wearer's crotch is reduced. However, this may lead to a decrease in the absorption capacity of the diaper 1. In order to prevent this, the absorbent core 4 is made separable from the diaper main body (the outer packaging material 11 in this embodiment) in the vicinity of both side edges in the width direction, and between the parts made separable. It is fixed to the diaper body. Specifically, the shape of the absorbent core 4 is devised as described below.

  As shown in FIG. 6, the absorbent core 4 in the diaper 1 of the present embodiment is a three-part body 4 a, 4 b, 4 c in which an absorbent material made of a stack of fluff pulp and a superabsorbent polymer extends in the longitudinal direction. It is divided into. These three divided bodies are entirely wrapped with a tissue paper (not shown), and constitute an integral absorbent core 4. The divided bodies 4 a and 4 c on both the left and right sides are divided from the central divided body 4 b at the center in the longitudinal direction of the absorbent core 4. The longitudinal direction front side part and rear side part of the absorptive core 4 are comprised only from the center division body 4b. The lower surface of the absorbent core 4 is bonded and fixed to an outer packaging material (not shown). In this case, the left and right divided bodies 4a and 4c are not fixed to the outer packaging material and are separated from the outer packaging material. It has been made possible. On the other hand, a divided body excluding the divided bodies 4 a and 4 c on both the left and right sides, that is, the central divided body 4 b is fixed to the outer packaging material 11. Due to such a configuration, while the diaper 1 is worn, the left and right divided bodies 4a and 4c stand up from the outer packaging material due to body pressure applied in the width direction of the absorbent core 4. For the purpose of improving the rising property of the divided body, it is preferable that an elastic body is disposed in the vicinity of the side edges of the divided bodies 4a and 4c on both the left and right sides. As a result, the substantial width of the absorbent core 4 approaches the width of the central divided body 4b. In short, although the width of the absorbent core 4 before wearing of the diaper 1 is large, the width of the absorbent core 4 during wearing becomes small, and the absorbent core 4 comes to fit the wearer's crotch appropriately. . At the same time, the absorption capacity of the absorbent core 4 as a whole is sufficiently ensured by the presence of the divided bodies 4a and 4c on the left and right sides. For these reasons, in the diaper 1 of the present embodiment, even if the amount of the absorbent core 4 present in the wearer's crotch portion is reduced, a decrease in the absorption capacity is prevented.

  The substantial width (adhesion width between the absorbent core 4 and the outer packaging material 11) of the absorbent core 4 during wearing of the diaper is preferably set to 20 to 90 mm. From the viewpoint of fit at the crotch C during wearing of the diaper and prevention of looseness, it is more preferably set to 20 to 80 mm, and further preferably set to 30 to 70 mm. Further, the width of the absorbent core 4 before the diaper is mounted (the total width of the absorbent core before the left and right divided bodies 4a and 4c are separated) is preferably set to 50 to 150 mm. From the viewpoint of improving the absorption performance of the crotch C, the width is more preferably 60 to 150 mm, and even more preferably 70 to 140 mm.

  In the diaper 1 of the present embodiment, the average value of the pressure when the diaper 1 is worn in the first region 71 described above is preferably 1.1 to 2.5 kPa, more preferably 1.1 to 2.0 kPa, The appearance of the diaper 1 in a worn state can be further improved by setting the pressure to 1.2 to 1.8 kPa more preferably. The first 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. 7, and the superior anterior iliac spine is a part indicated by 9b in FIG. Conventionally, in order to prevent slipping while wearing a pants-type diaper, particularly to prevent slipping while wearing a pants-type disposable diaper for infants, tightening an elastic member disposed in the waist opening It has been considered effective to increase the pressure and bring the pant-type diaper into close contact with the wearer's body through the waist 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, it corresponds to the wearer's iliac region rather than increasing the tightening pressure of the waist opening. It has been found that it is effective to increase the tightening pressure of the diaper part as compared with the prior art. The reason for this is that wearers, particularly infants, have their waists protruding as a physical feature, so if the tightening pressure of the waist opening that abuts the protruding belly is increased, the tightening pressure is high. This is because the waist opening is gradually narrowed down and the waist opening is shifted down to a site where the abdomen becomes thinner.

  The pressure when the diaper 1 is worn in the first region 71 can be controlled by adjusting, for example, the material, thickness, elongation rate, or arrangement interval of the first elastic member 71a.

  The pressure at the time of wearing the diaper 1 in the first region 71 is that the diaper 1 is mounted on a cylinder having a circumference of 500 mm, and the mounting pressure measuring device (contact pressure measuring device (AMI3037-2 manufactured by AIM Techno Co., Ltd.)). Measured by. The specific measurement method is as follows.

[Method for Measuring Pressure in First Region 71]
Using an air pack of φ = 15 mm, set the air pack so that the center of the air pack is positioned at the tip of the waist opening, and measure the mounting pressure (P1). 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 where the left and right side portions of the outer packaging material 11 from the waist opening to the leg opening 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 first region 71. For example, when P3 to P6 are applicable, the width of the region = (6-3) × 5 = 15 mm. The center of the first region 71 at that time is the midpoint between the measurement point 3 and the measurement point 6.

  The reason why the circumference of the cylinder is set to 500 mm is that the average length around the belly of an infant who is a main subject wearing the diaper 1 of the present embodiment is approximately 500 mm. The length of the abdomen around here is an average value of the abdomen circumference measured in the standing position and the sitting position in consideration of the change in the circumference of the abdomen when the posture of the infant changes.

  The part from the wearer's iliac crest to the upper anterior iliac spine has a certain width, and the first region 71 of the diaper 1 is fixed to the part within the range of the width. Can be more effectively prevented. From this viewpoint, in the diaper 1 of the present embodiment, the width of the first region 71 (that is, the length of the first region 71 along the longitudinal direction of the diaper 1) W1 is preferably set to 15 to 35 mm. When the width W 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 worn state and the operation of wearing the diaper 1 Easiness) can be further improved.

  In a state where the diaper 1 is worn, the relationship between the dimensions of the diaper 1 and the physique of the wearer in order for the first region 71 to abut on the site from the wearer's iliac crest to the superior anterior iliac spine. It is also important. 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 first region 71 of the ventral side A (center position along the longitudinal direction of the diaper 1) and the diaper 1. The distance K1 between the longitudinal direction center line CL of the diaper 1 is preferably 180 to 220 mm, and the center position of the first region 71 of the back side B (the central position along the longitudinal direction of the diaper 1) ) And the longitudinal center line CL of the diaper 1 is preferably 180 to 220 mm, whereby the first 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. 8, the abdominal side left and right center point at the horizontal position height of the upper anterior iliac spine is the upper anterior iliac spine height front center, and the dorsal side is the upper anterior iliac spine height. As the posterior center, the length from the center of the superior anterior iliac spine to the center of the posterior center of the superior anterior iliac spine via the crotch is defined as the longitudinal length of the superior anterior iliac spine. The numerical value obtained by adding the necessary length in consideration of the thickness of the diaper material is divided into two. By setting the distances K1 and K2 to 185 to 215 mm, particularly 190 to 215 mm, the first region 71 can be brought into more successful contact with the wearer's iliac region.

  Although the 1st field 71 exists in ventral part A and dorsal part B, the pressure at the time of wearing in ventral part A and dorsal part B does not need to be exactly the same. That is, if the pressure at the time of wearing of the 1st field 71 in ventral part A and back part B is 1.1-2.5 kPa, the material of an elastic body, thickness, extension rate, arrangement interval May be different in ventral side A and dorsal side B. However, if the configuration of the first region 71 of the ventral portion A and the back portion B is excessively different, 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 at the time of wearing. It may shift to either the front or back, and a defect may occur in the appearance of the diaper 1. Therefore, the ratio of (A−B) / A is within 30% when A is the greater pressure when the first region 71 is attached to the ventral portion A and the dorsal portion B, and B is the smaller one. It is 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. 9A and 9B, both side edges A1 and A2 of the ventral side A are not joined to both side edges B1 ′ and 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.

  It is preferable to mainly use the first elastic member 71 a disposed in the first region 71 for the tightening force in the diaper 1 of the present embodiment. In other words, unlike the conventional pants-type diaper, it is not necessary to use the tightening force by the elastic member arranged in the waist opening 5 as a main means for fixing the diaper 1 to the wearer's body. On the contrary, it has been confirmed by the present inventors that if the tightening force of the waist opening 5 is increased, the diaper 1 is displaced. From this viewpoint, in the diaper 1 of the present embodiment, the average value of the pressure of the waist opening 5 when wearing the diaper is set to 0.3 to 1.5 kPa, which is a lower value than that of the conventional pants-type diaper. It is preferable. This pressure is preferably 0.5 to 1.0 kPa lower than the average value of the pressure in the first region 71 when the diaper is worn. Moreover, by setting the pressure of the waist opening 5 at the time of wearing the diaper within the above range, there is an advantage that the waist opening 5 can be easily expanded when the diaper 1 is worn, and the wearing operation can be easily performed. If it is 0.3 kPa or less, the natural length of the diaper 1 before wearing becomes large, and problems such as poor appearance when viewed as clothes may occur.

  When the average value of the pressure of the waist opening 5 when wearing a diaper is more preferably 0.4 to 1.2 kPa, and more preferably 0.4 to 1.0 kPa, the diaper 1 is further displaced. It can be effectively prevented. The pressure of the waist opening 5 can be measured by the same method as the pressure of the first region 71 described above. That is, a cylinder having a circumferential length of 500 mm is inserted (attached) into the waist opening 5 of the diaper 1, and the center of the air pack of the attachment pressure measuring device is located at a position 15 mm in the diaper longitudinal direction from the front end of the waist opening. Measure the pressure. The measurement is performed at 10 points at intervals of 50 mm in the circumferential direction, and the average value is taken as the pressure at the waist opening. As shown in FIGS. 9A and 9B, when the position of the edge of the waist opening on the abdomen and the position of the edge of the waist opening on the back are misaligned, Of the region where the side overlaps, the position closest to the end is defined as the waist opening. The pressure of the waist opening 5 can be controlled, for example, by adjusting the material, thickness, elongation rate, or arrangement interval of the waist elastic member 51. When the pressure of the waist opening 5 falls within the pressure range of the first region 71, the position is included in the first region 71.

  In the diaper 1, it is preferable that the elastic members 61a and 61b are arranged in an extended state substantially along the leg opening. And it is preferable that the average value of the pressure of the leg opening part 6 at the time of diaper wear is 1.0-2.4 kPa, especially 1.2-2.2 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. Moreover, even if the weight in the crotch of the diaper 1 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 deteriorated. And leakage of urine and feces 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.

  Furthermore, in the diaper 1 of the present embodiment, when the diaper is worn, a region other than the first region 71, the waist opening 5 and the leg opening 6, for example, the first region 71 located between the first region 71 and the leg opening 6. The average value of the pressure in the two regions 72 is preferably 0.2 to 0.8 kPa, more preferably 0.3 to 0.6 kPa. As a result, the diaper 1 can be brought into close contact with the wearer's body with an appropriate pressure, and liquid leakage can be effectively prevented. When the diaper 1 is worn, the second region 72 contacts the lower region (lower abdomen) of the wearer's iliac region. The width of the second region 72 (that is, the length of the second region 72 along the longitudinal direction of the diaper 1) W2 is preferably 40 to 70 mm, particularly 45 to 65 mm.

  In this regard, in the diaper 1, when the pressures of the waist opening 5, the first region 71, and the second region 72 when the diaper is worn are compared, the pressure in the first region 71 is the highest, and then the waist It is preferable that the pressure in the opening 5 is high and the pressure in the second region 72 is the lowest. Providing such an order in the pressure of each part not only effectively prevents the diaper 1 from slipping off during wearing, but also the diaper 1 adheres to the wearer's body without a sense of incongruity, and liquid leakage is effective. Is prevented.

  In the present invention, the absorbent core 6 may be other than the embodiment shown in FIG. For example, in the embodiment shown in FIG. 6, the absorbent core 4 is divided into three in the longitudinal direction. However, if the divided bodies on the left and right sides of the divided body are separable from the outer packaging material, the number of divisions is three. It is not limited to four, but may be four or more.

  Moreover, as long as the absorptive core 4 can be separated from the diaper main body in the width direction both side edge vicinity, the shape of the absorptive core 4 is not restrict | limited to embodiment mentioned above. For example, as shown to Fig.10 (a), the absorptive core 4 may be a two-layer structure of the lower absorber 42 and the upper absorber 41 arrange | positioned on it. The upper absorber 41 is substantially T-shaped. The lower absorbent body 42 has a size larger than that of the upper absorbent body 42 and has a vertically long rectangular shape as a whole. The lower absorbent body 42 has a pair of non-stacking portions 43 along its longitudinal direction. The non-stacking portion 43 extends in the longitudinal direction of the lower absorbent body 42. The non-fiber-splitting portion 43 does not extend to each edge in the longitudinal direction of the lower absorbent body 42, and is formed only at a substantially central portion in the longitudinal direction of the lower absorbent body 42. Therefore, between each end part of the non-stacking fiber part 43 and each edge 42a in the longitudinal direction of the lower absorbent body 42 is a fiber stacking part 44, 44 in which there is no non-stacking part.

  Each non-stacking portion 43 is formed at a position symmetrical with respect to the longitudinal center line of the lower absorbent body 42. The non-stacking portion 43 has a substantially arcuate and elongated shape defined by a straight portion 45 and a circular arc portion 46 connected to each end of the straight portion 45. In each non-stacked fiber portion 43, the straight portion 45 is located closer to the outer side in the width direction of the lower absorbent body 42, and the arc portion 46 is located closer to the inner side in the width direction of the lower absorbent body 42.

  On the other hand, the leg part 41a of the upper absorbent body 41 having a substantially T-shape is located at a position between the non-stacking parts 43 in the lower absorbent body 42. The length of the leg part 41a is substantially the same as the length of the non-stacking part 43. The head portion 41 b of the upper absorbent body 41 is located on one stacking portion 44 of the lower absorbent body 42. The width of the head portion 41 b is slightly narrower than the width of the lower absorbent body 42. And in the absorptive core 4, the side in which the head 41b of the upper absorber 41 is located is distribute | arranged to the back side of a diaper.

  In the absorbent core 4 of this embodiment, the part located in the width direction outer side rather than the unstacked fiber part 43 among the lower absorbent bodies 42 is the divided bodies 4a on both the left and right sides of the absorbent core shown in FIG. This corresponds to 4c. Moreover, the part located between the non-stacking parts 43 among the lower absorbers 42 and the leg part 41a of the upper absorbent body 41 correspond to the divided body 4b in the central part of the absorbent core shown in FIG. According to the absorbent core 4 of the present embodiment, the non-stacking portion 43 has the substantially arcuate shape described above. The rising property of the part located in the direction becomes better.

  As a modification of the absorbent core of the embodiment shown in FIGS. 10A to 10C, the absorbent core 4 of the embodiment shown in FIGS. 11A and 11B can be used. The absorbent core 4 of the embodiment shown in FIGS. 11 (a) and 11 (b) is composed of only the lower absorbent body among the absorbent cores of the embodiment shown in FIGS. 10 (a) to 10 (c). It is. Also in the absorbent core of the present embodiment, a pair of elongated non-stacked fiber portions 43 each having a substantially arcuate shape are formed along the longitudinal direction of the absorbent core 4. The rising property of the portion located at is improved.

  Moreover, the absorptive core 4 of embodiment shown to Fig.12 (a) and (b) is a modification of the absorptive core shown to Fig.11 (a) and (b), and the shape where the non-stacking fiber part 43 was closed Not doing. The left and right divided bodies 4a and 4c extending in the longitudinal direction are connected to the central divided body 4b at one end thereof. Further, in the absorbent core 4 of the embodiment shown in FIG. 12 (c), a plurality of notches 4d are formed in the left and right side edges of the rectangular absorbent core 4, and the absorbent core is located between the notches 4d. 4 is separated from the diaper body. Furthermore, in the absorbent core 4 of the embodiment shown in FIGS. 12D and 12E, the absorbent core 4 has a two-layer structure of an upper layer 4e and a lower layer 4f. The shape of each of the upper layer 4e and the lower layer 4f is a diaper body in which a plurality of notches 4d are formed on the left and right side edges of the absorbent core 4 and the absorbent core 4 positioned between the notches 4d in a state where they are overlapped. The shape is such that it is separated from.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, the range of this invention is not restrict | limited to this embodiment. For example, 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.

[Examples 1 and 2 and Comparative Examples 1 to 3]
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 composed 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 diaper was attached to three 1 to 2 year old infants, and the mother was evaluated according to the following criteria for the wearability and wearing state at that time. The results are shown in Table 1.
(1) Looseness of inseam when wearing diapers ○: Not concerned △: Slightly anxious ×: Concerned (2) Ease of movement when wearing diapers ○: Easily movable △: Slightly moving ×: It is difficult to move (3) Ease of pants from the top of the diaper ○: Easy to make △: Slightly easy to make ×: Not easy to make (4) The inseam of the pants from the top of the diaper ○: Not concerned △: Somewhat anxious ×: Concerned (5) Displacement of diaper 60 minutes after wearing ○: No deviation △: Some deviation ×: Some deviation

  As is clear from the results shown in Table 1, it can be seen that the diaper of each example is easy to move with no looseness in the crotch when worn. In addition, it is easy to put on the trousers from the top of the diaper. It can also be seen that there is no diaper slippage. On the other hand, the diaper of Comparative Example 1 in which the width of the minimum width portion of the diaper crotch portion is large is that the diaper and the crotch of the trousers hung from the diaper are bumpy, and it is difficult to move and easily fall off. I understand. Since the distance between the lower ends of the diaper of Comparative Example 2 is large, it can be seen that the diaper and the groin of the trousers laid over the diaper are more uneven than the diaper of Comparative Example 1. It can be seen that the diaper of Comparative Example 3 is inferior in all evaluation items because the width of the minimum width portion of the diaper crotch portion is large and the distance between the lower ends is also large.

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. 4A to 4F are diagrams for explaining a novel design method for diapers, and FIGS. 4A to 4C are diagrams showing base patterns obtained by transferring body shapes. FIG. 4D is a diagram showing a modified base pattern obtained by modifying the base pattern, and FIG. 4E is a diagram in which the master pattern is modified in consideration of the expansion and contraction of the wearer's skin. FIG. 4 (f) is a diagram showing a final pattern obtained by correcting the corrected master pattern in consideration of ease of wearing (ease of wearing) and the like. . It is a figure which shows the measurement site | part etc. in the novel design method of a disposable diaper. It is a top view which shows the structure of an absorptive core. It is explanatory drawing which shows an iliac bone. It is explanatory drawing which shows the measuring method of upper anterior iliac spine height front and back length. Fig.9 (a) is a perspective view which shows another embodiment of the diaper of this invention, FIG.9 (b) is a top view which shows the unfolded state of the diaper shown to Fig.9 (a). 10 (a) to 10 (c) are plan views showing other embodiments of the absorbent core. 10A and 10B are plan views showing still another embodiment of the absorbent core. 12 (a) to 12 (e) are plan views showing still another embodiment of the absorbent core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent core 4a, 4b, 4c Divided body 5 Waist opening 6 Leg opening 71 First area 72 Second area

Claims (7)

A pants-type disposable diaper in which a waist opening and a pair of leg openings are formed,
In the unfolded state of the diaper, the distance between the lower end edge of the flap portion on the front side in the longitudinal direction and the lower end edge of the flap portion on the rear side portion is set to 210 to 280 mm and The width of the narrow part is 50 to 160 mm ,
Between the waist opening and the leg opening in each of the ventral side and the back side of the diaper, there is a region where the pressure when wearing the diaper is 1.1 to 2.5 kPa,
The region is formed at a site that contacts the site from the wearer's iliac crest to the upper anterior iliac spine when wearing a diaper,
A pants-type disposable diaper in which the pressure of the waist opening when wearing a diaper is lower than the pressure in the region when wearing a diaper.   The pants-type disposable diaper according to claim 1, wherein the absorbent core is separable from the diaper body in the vicinity of both side edges in the width direction, and is fixed to the diaper body between the separable parts. The width | variety of the said area | region is 15-35 mm, The underpants type disposable diaper of Claim 1 or 2. In the unfolded state of the diaper, the distance between the longitudinal center line and the center position of the region on the ventral side is 180 to 220 mm, and the center position of the region on the back side from the longitudinal center line The underpants type disposable diaper according to any one of claims 1 to 3, wherein the distance between them is 180 to 220 mm. The pants-type disposable diaper according to any one of claims 1 to 4, wherein the region mainly exists between left and right side edges of the diaper and left and right side edges of the absorber. A first region extending in the width direction of the diaper, and a region between the first region and the leg opening between the waist opening and the leg opening in each of the ventral side and the back side of the diaper. A second region is formed;
When comparing the pressure of the waist opening, the first region, and the second region when wearing the diaper, the pressure of the first region 71 is the highest, then the pressure of the waist opening is high, and the pressure of the second region is Lowest,
The pants-type disposable diaper according to any one of claims 1 to 5, wherein the region where the pressure when wearing the diaper is 1.1 to 2.5 kPa is the first region .   The underpants type disposable diaper in any one of Claim 1 thru | or 6 with which the pressure of the said waist opening part at the time of diaper wear is 0.3-1.5kPa.

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