JP4212518B2 - Disposable diapers - Google Patents

Description

  The present invention relates to a pants-type disposable diaper that can be easily squeezed.

  Conventionally, as a disposable diaper, a pants-type diaper for a child (older-aged child) who can stand up or walk by himself is known (see Patent Document 1).

Japanese Patent Laid-Open No. 2001-478

Conventionally, a pants-type disposable diaper has been used by letting an infant in a standing state pass one leg through both leg openings.
For this reason, it has not been considered to allow a young child who cannot turn over or to stand and wear, especially in a laid state. Therefore, a pants-type diaper that can be suitably used for low-age children has not been provided yet.

  It is an object of the present invention to prevent leakage from around the legs while preventing the legs from being excessively tightened, and to easily pass the baby's feet through the leg openings when wearing diapers. Accordingly, it is an object of the present invention to provide a disposable diaper that can be easily put on a baby and can be easily removed even in a sleeping state, particularly a pant-type disposable diaper suitable for a low-age child.

  The present invention includes a liquid-retaining absorbent body, has an abdominal side portion, a crotch portion, and a dorsal side portion, and both side edges of the abdominal side and both sides of the back side. A pants-type disposable diaper in which a waist opening and a pair of leg openings are formed, and the side edges of the ventral side and the side edges of the back side are , Each of which is joined by a detachable joining means, from the minimum value L1 of the crotch width and the point P on the opening edge of each leg opening located at the part where the crotch width becomes the minimum. The object was achieved by providing a disposable diaper in which the ratio (L1 / L2) to the diaper longitudinal distance L2 to the end point Q on the ventral side of the edge is 1.7 to 2.2. Is.

The disposable diaper of the present invention can prevent leakage from around the leg without excessively tightening the leg, and easily puts the baby's foot through the leg opening when the diaper is worn. Can be easily put on the baby, and can be easily removed even when lying down.
The disposable diaper of the present invention is not limited to use for a low-age child, but is particularly suitable for a low-age child and has an advantage that it can be easily applied to a newborn baby who is sleeping.

The present invention will be described below based on preferred embodiments with reference to the drawings.
The disposable diaper 1 as one embodiment of the present invention is a pants-type diaper as shown in FIG. As shown in FIGS. 2 and 3, the diaper 1 has a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid-retaining absorbent 4 interposed between both sheets 2 and 3. It comprises an absorbent main body 10 and an exterior body 5 that is positioned on the outer side (non-skin contact surface side) of the absorbent main body 10 to jointly fix the absorbent main body 10 and is worn by the wearer's stomach. It has an abdominal side A disposed on the side, a back side B disposed on the back side, and a crotch C positioned therebetween. And the both-sides edge part of the ventral | abdominal side part A and the both-sides edge part of the back | dorsal part B are joined so that peeling is possible with a mechanical hook-and-loop fastener. By the joining, a pair of side seal portions 50 and 50, a waist opening 7 and a pair of leg openings 8 and 8 are formed in the diaper 1.

  As shown in FIG. 2, the absorbent main body 10 has a vertically long rectangular shape, the longitudinal direction of which coincides with the vertical direction of the diaper 1 (also referred to as the vertical direction of FIG. 2 or the diaper longitudinal direction), and is externally covered by a known joining means. It is joined to the central portion in the width direction of the body 5. The absorber 4 has an hourglass shape in which the central portion in the longitudinal direction is constricted, and is sandwiched and fixed between the top sheet 2 and the back sheet 3.

  As shown in FIGS. 2 and 3, the absorbent main body 10 is formed with a pair of first three-dimensional guards 6A, 6A and second three-dimensional guards 6B, 6B extending in the longitudinal direction on the left and right sides thereof. As shown in FIG. 3, the first three-dimensional guard 6 </ b> A has a free end 61 </ b> A on the inner side in the width direction of the absorbent main body 10 and a fixed end (rising base end) 62 on the outer side. . An elastic member 63A is disposed in the vicinity of the free end 61A so as to be extendable and retractable along the free end 61A. On the other hand, the second three-dimensional guard 6 </ b> B has a fixed end 64 with the exterior material 5, and has a free end 61 </ b> B on the outer side in the width direction than the fixed end 64. In the vicinity of the free end 61B, an elastic member 63B is disposed so as to be stretchable along the free end 61B.

  As shown in FIGS. 2 and 3, the exterior body 5 is composed of a laminated body of an outer layer sheet 51 and an inner layer sheet 52. The outer layer sheet 51 is the outermost surface of the diaper 1, and the inner layer sheet 52 is disposed adjacent to the outer layer sheet 51 on the inner surface side of the diaper 1. The outer layer sheet 51 has extending portions extending in the front-rear direction from the front and rear end edges of the inner layer sheet 52, and each of the extending portions has the absorbent main body 10 disposed on the inner layer sheet 52 of the exterior body 5. After that, the absorbent main body 10 is folded back and bonded so as to cover the front and rear ends of the absorbent main body 10.

  As shown in FIGS. 1 and 2, the diaper 1 has a pair of side gathers (stretchable parts that expand and contract in the width direction) 90 on the waist parts D1 and D2 of the abdominal part A and the back part B, respectively. Therefore, the waist part D of the diaper 1 has elasticity in the circumferential direction. Moreover, it has the waist gathers 70 in each waist part E1, E2 in the abdominal part A and the back part B, and, thereby, the waist part E of the diaper 1 has a stretching property in the circumferential direction.

As shown in FIGS. 1 and 2, the waist gather 70 has waist elastic members 71 on the waist portions E1 and E2 on the abdominal side A and the back side B, and the opening edge 72 of the waist opening 7 respectively. It is formed in a stretched state so as to extend along.
The pair of side gathers 90, 90 fix a plurality of elastic members 91 in an expanded state to the waist portions D 1, D 2 in the abdominal side A and the back side B, respectively, in the circumferential direction of the waist portion D. Is formed. These elastic members 91 are disposed and fixed in an extended state at least on the outer sides in the width direction from both side edges of the absorber 4 and are elastically stretchable at least in the center in the width direction of the portion overlapping the absorber 4. It is not arranged in a state where is expressed. The elastic member 91 is arrange | positioned in the state divided | segmented into two in the width direction of a diaper.

A leg gather 80 is formed in the leg opening 8 along the opening edge 82. The leg gather 80 is formed by fixing a plurality of elastic members 81 in an extended state along the opening edge portion 82.
Each of the elastic members 71, 81, 91 is sandwiched and fixed between the outer layer sheet 51 and the inner layer sheet 52 constituting the exterior body 5.

The diaper 1 is for low-age children and has a crotch length of 220 mm or less. The length L4 of the crotch is ½ of the total length LT (see FIG. 4) in the expanded and extended state.
Here, the expanded and extended state means that the side seal portion is peeled off, the diaper is set in the expanded state, the elastic member of each part is expanded in the expanded diaper, and the design dimensions (the influence of the elastic member is eliminated at all). In this state, it is expanded until it becomes the same size as when expanded in a flat shape.

  As shown in FIG. 4, the diaper 1 has a crotch width (a distance in the diaper width direction between the opening edges 82 of the pair of leg openings 8, 8) L, and the crotch width L The distance in the vertical direction of the diaper from the point P on the opening edge 82 of each leg opening 8 to the end point Q on the ventral side A side of the opening edge 82 of the leg opening 8, which is located at the smallest part ( The distance (L1 / L2) to the distance L2 measured along the longitudinal direction of the diaper is 1.7 to 2.2, preferably 1.8 to 2.0. By making it within this range, even if it is a body shape that is bent in the shape of a leg like a low-age child, it is easy to put it on while lying down by the wearing method as described later, and it was put on The excrement is less likely to leak from the leg opening.

  The inventors of the present invention have found that when a conventional pants-type diaper for high-aged children is reduced in size to be worn by a low-aged child, it is difficult for the legs to pass through. When the cause was examined, it was first found that there was a cause in the stretching force of the leg opening. In other words, diapers for high-aged children with a large amount of excretion are provided with strong stretching force to prevent leakage from the leg opening, which makes it difficult to open the leg opening when the low-aged child is laid, It is difficult. However, when the expansion / contraction force of the opening is weakened to solve this problem, the excrement leaks easily. In other words, it has not been easy to develop a pants-type diaper that makes it difficult for excrement to leak even if the stretching force is reduced, and that a parent can easily wear even when a low-age child is sleeping.

However, as a result of various studies, the present inventors have found that in conventional pants-type diapers for older children, L1 / L2 is small (less than 1.7) and there is a correlation between leakage. . Therefore, when this value was increased, it was found that leakage from the leg opening dramatically decreased. Moreover, in that case, it has also been found that sufficient leakage prevention performance can be obtained even if the stretching force applied to the leg opening is not so strong. However, on the other hand, when this value is increased indefinitely, it has been found that the legs bent in the shape of a circle like those at the time of low age are difficult to pass through the leg openings and are difficult to wear. In particular, when the function of the joint is not sufficiently developed like a newborn baby, even the motivation to wear it too much fears dislocation. Therefore, the above range is preferable for the body shape of a low-age infant because it is possible to achieve both prevention of leakage and ease of wearing.

As shown in FIG. 4, the diaper 1 has a front body F on the abdominal side A side from a center line (a center line extending in the diaper width direction) that bisects the total length LT in the expanded and extended state. And the front body F when it is divided into the back body G from the back side part has a part where the crotch width L is minimum. The crotch width L gradually increases from the portion toward the longitudinal direction of the diaper longitudinal direction.
In addition, when the crotch width L shows the minimum value over the predetermined length of a diaper longitudinal direction, let the site | part closest to the center of a longitudinal direction be a site | part where a crotch width becomes the minimum. However, in this case, it is preferable that the portion showing the minimum value is within 1/10 of the total length of the diaper from the center in the longitudinal direction of the diaper toward the end.

  The diaper 1 has an opening edge of the leg opening 8 from a minimum value L1 of the crotch width L and a point P on the opening edge 82 of each leg opening 8 located at a position where the crotch width L is minimum. The ratio (L1 / L3) to the distance (the distance measured along the diaper width direction) L3 to the imaginary straight line La in the diaper vertical direction passing through the end point Q on the ventral side A of 82 is 2.0 to 2.5. In particular, it is preferably 2.2 to 2.4. By setting the ratio (L1 / L3) within the above range, it becomes a shape more suitable for the bent shape of both legs opened to the left and right like a baby lying on his back, particularly a low-aged infant.

  Further, as shown in FIG. 4, the diaper 1 includes a phantom line Hb surrounded by an imaginary straight line Lb connecting the point P and the end point Q and an opening edge 82 of the leg opening 8. An imaginary straight line Lc in the diaper vertical direction passing through the point P, an imaginary straight line Ld in the diaper width direction passing through the upper end Q of the leg opening 8 perpendicular to the imaginary straight line Lc, and the virtual straight line Lb. The area ratio (S1 / S2) of both regions is 0.45 to 0.55, particularly 0, where S2 is the area of a right triangle region (region H and region J) surrounded by It is preferable that it is .46-0.50. By setting the ratio (S1 / S2) within the above range, it is easier to pass the baby's foot through the leg opening when the diaper is worn, and the lifting after passing the foot is also easier. .

In the diaper 1 of the present embodiment, the minimum value L1 of the crotch width L is 150 to 170 mm, and the distance L2 is 75 to 95 mm. With the L1 / L2 in the range described above, the L1 and L2 in this range, the legs of low age Solid type is more easily passed through. In particular, regarding L2, the excrement is particularly difficult to leak from the leg opening when it is in the above range.

Further, the distance L3 is 65 to 75 mm, the area S1 is 13.5 to 19.0 cm ² , and the area S2 is 25.0 to 35.0 cm ² , because it is gentle to the wearer's leg. preferable.

  The diaper 1 of the present embodiment is surrounded by a virtual straight line Le that connects the point P and the end point Q ′ on the back side B of the opening edge 82 of the leg opening, and the opening edge 82 of the leg opening. The area of the cut-out circular region K is S3, a virtual straight line Lc in the diaper vertical direction passing through the point P, a virtual straight line Lf in the diaper width direction passing through the end point Q ′ perpendicular to the virtual straight line Lc, and The area ratio (S3 / S4) of the two regions is 0.45 to 0.4 when the area of a right triangular region (region K and region M combined) surrounded by the virtual straight line Le is S4. 55, especially 0.46 to 0.50.

  As described above, the side seal portion 50 in the diaper 1 is formed by joining both side edges of the abdominal side A and both side edges of the back side B so as to be peeled off by a mechanical hook-and-loop fastener. Is formed.

  Here, the mechanical hook-and-loop fastener is composed of a male sheet having a large number of protruding male engagement portions disposed on the surface, and a female sheet having a loop portion, a mesh portion, etc. disposed on the surface. That is, it refers to a fastening device that is configured so that a male sheet and a female sheet are brought into contact with each other so as to be joined together.

  As the mechanical surface fastener, various known ones can be used without particular limitation. For example, “Magic Tape (registered trademark)” (manufactured by Kuraray), “Quicklon (registered trademark)” (manufactured by YKK), “ “Majikurosu (registered trademark)” (manufactured by Kanebo Bell Touch) or the like can be used. Examples of the male engagement portion of the male sheet include a hook shape, a hook shape, a mushroom shape, and the like.

The male surface sheet of the mechanical surface fastener may be obtained by fixing a separately manufactured male engagement portion to a base material sheet (resin sheet or the like) by a bonding means such as an adhesive or heat fusion. The base sheet and the male engagement portion may be integrally formed.
As the female sheet of the mechanical hook-and-loop fastener, for example, a base sheet (resin, paper, non-woven sheet, etc.) formed by fixing synthetic fibers or the like so that a large number of loop portions are formed is used. However, a fiber sheet such as a normal nonwoven fabric can be used as the female sheet.

In the diaper 1 of the present embodiment, as shown in FIGS. 2, 6 and 7A, the male seat 53 is provided on the skin contact surface side (inner surface side) at both side edges of the back side portion A. It is stuck. The outer layer sheet 51 that forms the non-skin contact surface of the ventral portion B is formed of a fiber sheet, more specifically a nonwoven fabric, with which the male sheet 53 can be directly engaged. Functions as a mold sheet.
As a nonwoven fabric when using a nonwoven fabric as a female-type sheet, an air-through nonwoven fabric, a spunbond nonwoven fabric, a heat roll nonwoven fabric, a chemical bond nonwoven fabric, and the like can be used. Is preferably used. Moreover, as a fiber which comprises a nonwoven fabric, a short fiber staple fiber, a long fiber filament, etc. can be used. Moreover, a core-sheath type or a side-by-side type composite fiber can also be used. Various thermoplastic resins can be used as the constituent material of the fiber.

In particular, it is preferable to use a core-sheath type composite fiber as the main constituent fiber of the nonwoven fabric, and it is particularly preferable to use a core-sheath type composite fiber made of the same series of resin components. In this specification, the resin components of the same series are similar to each other in the chemical structure of the resin component constituting each of the sheath component and the core component (that is, the main chemical structure is the same), and are compatible with each other. By seed resin or resin mixture. In this case, it is desirable that the interfacial strength between the core component and the sheath component is greater than the joint strength. When the nonwoven fabric is composed of two or more kinds of fibers, it is preferable that the main constituent fiber is a core-sheath type composite fiber made of the same series of resin components, and the ratio of the composite fiber is particularly high. It is preferably 50% by weight or more.
As a specific combination of the core component and the sheath component, polypropylene (PP) is used as the core component, a low melting point PP is used as the sheath component, polyethylene terephthalate (PET) is used as the core component, and a low melting point is used as the sheath component. Examples include combinations using PET.

  The male sheet 53 is preferably long in the longitudinal direction of the diaper in order to make it difficult to come off at the time of wearing or wearing, and particularly in order to make it difficult to come off at the time of wearing. The length (total length in the case of a plurality of divided pieces) L5 is 85 to 105 mm, and the length L6 in the width direction is preferably 10 to 20 mm, more preferably 10 to 20 mm, and the end point Q The distance L2 in the vertical direction of the diaper is preferably 75 to 95 mm.

  The diaper 1 of the present embodiment can be particularly easily applied to a newborn who is lying on his back. The method for attaching the diaper is not particularly limited, but an example of a preferred method for attaching is shown below.

(Installation method)
As shown in FIG. 5 (a), one hand is inserted into one leg opening 8, and one leg is grasped by that hand, and the leg is opened as shown in FIG. 5 (b). Pull out from. Then, as shown in FIG. 5C, the other leg is similarly pulled out from the other leg opening. When both feet pass, the diaper is pulled up to the wearer's waist as shown in FIG. In this way, the diaper 1 can be easily attached to a newborn or the like lying on his back.

According to the diaper 1 of this embodiment, when the ratio (L1 / L2) is in the specific range, the shape of the leg opening portion is a baby sleeping in a supine position, in particular, the legs are opened to the left and right. It is very suitable for inserting the leg of a newborn.
Therefore, for example, when a diaper is worn by the preferred wearing method described above, after inserting the hand into the leg opening and grasping the baby's foot, the operation of pulling out the baby's foot from the leg opening with that hand is very smooth. It can be carried out.
In addition, the shape of the leg opening is particularly suitable for fitting the leg opening to a baby, particularly a newborn's leg, so that the elastic member 81 provides a strong contracting force to the leg opening. Even if it is not applied, a sufficient fit can be obtained around the legs. Therefore, it is possible to prevent excessive pressure around the baby's leg.

Moreover, since the side seal part 50 is joined by the mechanical surface fastener which is the detachable joining means, the diaper 1 of this embodiment can remove a diaper only by peeling off the side seal part 50. Therefore, the diaper can be easily replaced in the same manner as a so-called tape diaper (expandable diaper). Moreover, as shown in FIG. 6, since the diaper 1 can be easily removed even when the baby is laid down, it is safe because stool is not leaked.
In general, the side seal part 50 remains joined, and the so-called pant-type diaper is stretched, and the stretchable waist opening is stretched to check whether there is urination or fecal excretion. Parents can confirm.
Furthermore, the diaper 1 of the present embodiment can be used for the left and right side seal parts 50 without removing the diaper during wearing even when it is difficult to visually recognize by simply stretching the waist opening where there is a small amount of excrement in the crotch and the like. Since only one side or only a part of one side seal part can be opened and then joined again, check for urination and defecation during wearing, and rejoin if there is no urination. It is also possible.
The disposable diaper of the present invention is different from a conventional so-called tape diaper (expandable diaper) in that it is worn (or wearable) with the left and right side seals being joined. It is.

  Moreover, as shown in FIGS. 6 and 7 (a), since both side edges of the dorsal side B are joined to the non-skin contact surface side of the ventral side A, the ventral side A It is possible to prevent the side seal portion from coming into contact with a carpet, a mattress or the like and unintentionally peeling off the side seal portion, and the side seal portion 50 is excellent in peelability. Moreover, since the male sheet 53 of the mechanical hook-and-loop fastener is provided on the back side B side, the diaper after use is unfolded and rounded in the longitudinal direction from the abdominal side, and the outer surface of the rolled diaper is By fastening the male sheet, the rolled state of the diaper can be stably maintained. Thereby, a diaper can be disinfected hygienically as a compact form.

  As the detachable joining means in the present invention, a combination of a button and a button hole, a hook and a hook, an adhesive part and an adhesive part to which the adhesive part can be peeled can be used in addition to the mechanical surface fastener. Even if these are used, the same effect can be obtained. However, it is preferable to use a mechanical hook-and-loop fastener from the viewpoint of easily releasing the joined state of the side seal portion when changing diapers or confirming urination. Furthermore, in the case of the diaper 1 of this embodiment in which the outermost layer is formed using a nonwoven fabric that can be bonded and fixed to the male sheet 53 of a mechanical surface fastener, when the diaper is discarded after use, the diaper is rolled up Since the male surface sheet 53 of a mechanical surface fastener can be easily joined to the outermost layer, it is preferable to use a mechanical surface fastener from the viewpoint of discardability such as almost no restrictions on the form to be rolled.

  Further, in the diaper 1, a part 81 a of the above-described elastic member 81 for forming leg gathers extends into the side gathers (expandable portions) 90 in the waist portions D <b> 1 and D <b> 2 in the ventral side portion A and the back side portion B. is doing. The term “extends into the stretchable part” means that a part 81a of the elastic member 81 enters between the elastic members 91 adjacent to each other in the region where the elastic member 91 is disposed, specifically, in the vertical direction of the diaper. Means that A part 81a of the elastic member 81 may enter only one of the expansion and contraction parts of the abdominal part A and the back part B.

Moreover, as for the diaper 1, as mentioned above, the leg gathers 80 are formed in the leg opening part 8 along the opening edge part, and it is a pair of three-dimensional objects along the diaper longitudinal direction on both sides of the diaper longitudinal direction. Guards 6B and 6B are formed. Therefore, even if the expansion / contraction force of the leg gather opening is further weakened, the excrement leakage preventing effect is high, so that a gentle touch can be given to the wearer.
Such an effect is achieved if at least a pair of solid guards are present. In other words, this is also achieved when only one of the first three-dimensional guard and the second three-dimensional guard is present.

  When the portion where the leg gather is formed is extended to a length obtained by subtracting 10 mm from the maximum extension length, the tensile load (hereinafter referred to as the leg gather extension load) is 100 to 250 cN, particularly 150 to 220 cN. It is preferable from the point that it fits easily without rubber marks. In the diaper of the present invention, for example, even from such a small stretching stress, leakage from the leg opening is sufficiently suppressed.

The elongation load of leg gathers is measured as follows.
[Measurement method of leg gather elongation load]
A part where the leg elastic member is arranged is cut out from the diaper with a necessary width, and is extended in a direction corresponding to the longitudinal direction of the diaper using a Tensilon tensile tester. In this embodiment, RTA-100 manufactured by Orientec Co., Ltd. was used. Here, the “necessary width” means a minimum width necessary for measuring the extension load of the part, and does not require an unnecessarily large width (for example, cut out with a width including the absorber). Means that it is not necessary).
The distance between the initial chucks is a length obtained by subtracting 50 mm from the natural length in the vertical direction (the length in a natural state in which the elastic member is not stretched, which is referred to as an initial length), and both ends of the sample are used as chucks. Pinch. Next, the elastic member or / and the fixing member of the member (gather part) fixing the elastic member in a stretched state breaks under the condition that the crosshead moving speed is 300 mm / min. Up to the maximum length, the natural length of the elastic member when the elastic member is not fixed to the chuck, and the maximum length when the elastic member is stretched when the elastic member is hardly extended E) Extend to -10 mm. And let the tensile load in the length of the maximum expansion | extension length -10mm be an extension load of a leg gather.

As a material which comprises each part of the diaper 1 of this embodiment, what is normally used in the said technical field can be especially used without a restriction | limiting.
For example, as the surface sheet 2, a hydrophilic and liquid-permeable nonwoven fabric or an apertured film can be used. As the back sheet 3, a resin film, a laminate material of a resin film and a nonwoven fabric, or the like can be used. As the absorbent body 4, a product obtained by wrapping a mixed fiber of fluff pulp and superabsorbent polymer particles with tissue paper, nonwoven fabric or the like (hereinafter referred to as packaging material) can be used. As the sheet constituting the three-dimensional guard, a water-repellent nonwoven fabric is preferably used. As the outer layer sheet 51 and the inner layer sheet 52, nonwoven fabrics produced by various production methods are preferably used.

As the elastic member of each part, various known elastic members can be used. For example, as the form of each elastic member, a thread-like thing (thread rubber etc.), a belt-like thing of a predetermined width (flat rubber etc.), Examples of materials for forming elastic members include natural rubber, synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, EVA, stretchable polyolefin, urethane, and the like. it can.
The elastic member 81 for forming leg gathers is preferably in the form of a flat rubber, the waistline elastic member 90 is preferably in the form of a rubber thread, and the waist elastic member 71 is preferably in the form of a flat rubber. .

  The absorber 4 is preferable from the point of being easily fit along the crotch of the baby when the bending rigidity is 1 to 25 cN / 50 mm. The bending rigidity includes rigidity in the longitudinal direction of the diaper and bending rigidity in the width direction, but at least the bending rigidity in the width direction is preferably within the above range.

The bending rigidity of the absorber 4 can be measured as follows.
[Measurement method of bending stiffness]
The measurement is performed using a Tensilon tester [RTC-1150A manufactured by Orientec Co., Ltd.] in accordance with JIS standard K7171 method (plastic-bending property test method) (R1 = 5.0 ± 0). 0.1 mm, R2 = 5.0 ± 0.2 mm).
The test piece is placed so as to pass between both edges of the support base having an edge span L of 50 mm, and the tip of the indenter is arranged so as to slightly contact the test piece. A load-deflection curve is obtained by lowering the indenter under conditions of a load cell of 5 kg (range: 200 cN) and a speed of 30 mm / min. Let the maximum value of the obtained bending stress be a bending rigidity value (cN / 50 mm).

[Method for preparing test piece]
The test piece is taken out of the absorbent article including a packaging material that does not contain a film from the absorbent article, and is cut into a rectangular shape of 50 mm in the longitudinal direction of the diaper and 80 mm in the width direction from the center in the longitudinal direction and the width direction. 50 mm in the unit of the flexural rigidity value is the length of the short side of the test piece, and is the width of the test piece bent with the indenter at the time of the test. The test piece is bridged between both edges, with the long sides thereof aligned in the direction from one edge to the other. When measuring the bending rigidity in the diaper width direction, a test piece having a diaper longitudinal direction of 80 mm and a width direction of 50 mm is cut out.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the both side edges of the ventral side A and the both side edges of the back side B are, as shown in FIGS. 7 (c) and 7 (d), the side edges of the ventral side A as the back side. You may join in the state piled up on the non-skin contact surface side of B. Further, the male sheet 53 of the mechanical hook-and-loop fastener is preferably provided on the back side B side in order to fix the diaper after use in a rolled state, but instead, As shown in FIG.7 (b) and FIG.7 (c), it can also provide in the ventral | abdominal part A side. Moreover, as shown to Fig.8 (a)-FIG.8 (c), you may vary the side which provides a male type sheet | seat in the left and right side seal part.

<Example 1>
The disposable diaper of the form shown in FIGS. 1-3 was manufactured.
The dimensions and physical properties of each part are shown in Table 1.

<Comparative example>
A diaper was manufactured in the same manner as in Example 1 except that the ratio (L1 / L2) was 1.5 (L1 = 160 mm, L2 = 107 mm).

<Reference example>
A diaper was manufactured in the same manner as in Example 1 except that the ratio (L1 / L2) was 2.3 mm (L1 = 160 mm, L2 = 107 mm).

<Performance evaluation>
For each disposable diaper, 1) ease of attachment to a newborn and 2) urine crotch prevention performance were evaluated by the following methods. The results are shown in Table 2.
1) Ease of wearing (evaluation of ease of foot passage)
〔Evaluation methods〕
Each diaper was attached to a newborn baby model (the one bent in a leg shape in the stationary mode) by the above-mentioned mounting method, and evaluated for ease of passing the leg through the leg opening in the laid state. .
(Evaluation criteria)
When passing a leg, it was marked as ○ if it was easy to pass, and × if it was difficult to pass.
“Easy to pass” means that it is easy to pass both feet, and in particular, it can be passed smoothly when passing the other foot after passing one foot. Being difficult to pass means that it is difficult to pass both feet, but it is particularly difficult to pass the other foot after passing one foot.

2) Prevention of urine crotch leakage (measurement of crotch leakage value)
〔Evaluation methods〕
A diaper was attached to a low-age model (a model in which artificial urine can be injected from the crotch part and imitatively imitated the waist of a low-age child), and the crotch level was measured by the following method.
In the measurement of the crotch level, first put the diaper on the above-mentioned low-age model, first set it 90 degrees sideways, and tilt it 45 degrees back as it is. 30 g of artificial urine was injected through the tube at a rate of 5 g / second, and it was visually checked whether there was any leakage after injection. For those in which no leakage occurred, 40 g of artificial urine was injected in the same manner, and such an operation was repeated until it leaked. The total amount of artificial urine injected at the time when leakage of urine was observed was taken as the crotch mole value.

  From the results shown in Table 2, it can be seen that the disposable diaper of the example is easy to pass the baby's feet and is difficult to leak from the crotch. On the other hand, the diaper of the comparative example is easy to pass the baby's feet, but easily creates a gap in the crotch, and is easy to leak. The diaper of the reference example is difficult to move, but it is difficult to pass the other leg after passing one leg, so it is difficult to pass the baby's leg.

FIG. 1 is a perspective view showing a disposable diaper as an embodiment of the present invention. FIG. 2 is a plan view showing a developed and extended state of the disposable diaper of FIG. FIG. 3 is a schematic cross-sectional view showing a cross section taken along the line II in FIG. 2 (a cross section of a portion where the crotch width is minimum). FIG. 4 is a plan view for explaining the outer shape of the disposable diaper of FIG. 1 in the expanded and extended state. FIG. 5 is a diagram showing a state in which the disposable diaper of FIG. 1 is attached to a newborn, FIG. 5 (a) is a state in which a hand is inserted into one leg opening from the outer surface side of the diaper, and FIG. Fig. 5 (c) shows a state in which one leg of a baby sleeping on its back with its hand is pulled out from one leg opening, and the other leg is similarly pulled out from the other leg opening, FIG.5 (d) is a figure which shows the state which pulled up the diaper and completed mounting | wearing. FIG. 6 is a perspective view showing a state where the disposable diaper of FIG. 1 is removed from a sleeping baby. It is a figure which shows the example of the joining state of the side seal part in the disposable diaper of this invention, FIG.7 (a) is the joining state of the diaper shown in FIG. 1, FIG.7 (b)-FIG.7 (d) are each other. It is a figure which shows the joining state in the diaper of embodiment. It is a figure which shows the further another example of the joining state of the side seal part in the disposable diaper of this invention, and in any of FIG. 8 (a)-FIG. A male seat is provided on the abdominal side of the other side seal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Back sheet 4 Absorber 50 Side seal part 53 Male sheet | seat 6A, 6B of a mechanical hook-and-loop fastener 7 Waist opening part 70 Waist gather 8 Leg opening part 80 Leg gather 82 Opening edge part 90 Side Gather A Abdominal side B Back side C Crotch P Point on the opening edge of the waist opening located at the position where the crotch width is the minimum Q End point on the ventral side of the opening edge of the waist opening

Claims (8)

It has a liquid-retaining absorbent body, has an abdominal part, a crotch part, and a dorsal part, and both side edges of the abdominal part and both side edges of the dorsal part are joined, and a waist opening and a pair of A pants-type disposable diaper in which a leg opening is formed,
Both side edges of the abdominal side and both side edges of the back side are joined by detachable joining means, respectively.
Diaper from the minimum value L1 of the crotch width and the point P on the opening edge of each leg opening located at the position where the crotch width is minimum to the end point Q on the ventral side of the opening edge the ratio of the vertical distance L2 (L1 / L2) is Ri der 1.7 to 2.2,
The area of the region surrounded by the virtual straight line Lb connecting the point P and the end point Q and the opening edge of the leg opening is S1, the virtual straight line Lc in the vertical direction of the diaper passing through the point P, and the virtual The area ratio (S1 / S2) of the two regions is 0 when the area of the region surrounded by the virtual straight line Ld in the diaper width direction passing through the end point Q and perpendicular to the straight line Lc and the virtual straight line Lb is S2. .45-0.55,
Is for low age children, the minimum value L1 of the crotch width 150～170Mm, the area S1 is Ru 13.5～19.0Cm ² der, disposable diapers.   The disposable diaper according to claim 1, wherein the joining means is a mechanical surface fastener.   The ratio (L1 / L3) between the minimum value L1 of the crotch width and the distance L3 from the point P to a virtual straight line La in the diaper vertical direction passing through the end point Q is 2.0 to 2.5. The disposable diaper according to 1 or 2. The leg opening is formed with leg gathers along the edge of the opening, and the portion where the leg gathers are formed has a tensile load when extended to a length obtained by subtracting 10 mm from the maximum extension length. any disposable diaper according to claim 1 to 3 is 100～250CN. The said leg-opening, its has leg gathers along the opening edge portion is formed on both sides of the diaper longitudinally claim 1-4 in which at least one pair of stereoscopic guard along the diaper longitudinal direction is formed The disposable diaper as described in any one of. The disposable diaper according to any one of claims 1 to 5 , wherein a crotch length is 220 mm or less. The both side edges of the ventral side and the side edges of the back side are joined in a state where the side edges of the back side overlap the non-skin contact surface side of the ventral side. any disposable diaper according to claim 1-6. The disposable diaper according to any one of claims 3 to 7 , wherein the joining means is a mechanical hook-and-loop fastener, and a male-type sheet of the mechanical hook-and-loop fastener is provided on the back side portion side.

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