JP4416721B2 - Disposable diapers - Google Patents

Description

  The present invention relates to a disposable diaper, and more particularly to a disposable diaper excellent in preventing stuffiness and leakage.

A general conventional pants-type disposable diaper may cause stuffiness during wearing. For example, when a guardian changes an infant's diaper, it is often found that the skin near the infant's crotch is moist as moa when the diaper is removed. This is because the absorbent body that absorbs and holds excreted urine and the like is in close contact with the skin mainly on the wearer's crotch through the surface sheet, and the humidity near the skin surface is increased. In particular, when the wearer is an infant, there are many cases in which he / she cannot express his / her discomfort himself / herself, and the skin may be left moist for a long time, which may cause skin troubles.
In addition, when the outside air temperature is low, such as in winter, there is a concern that the absorbent body or the like cooled by the outside air may come into close contact with the wearer's skin and reduce the body temperature of the wearer together with the stuffiness.

As a method for preventing the above-described stuffiness, it is conceivable that an absorbent body that absorbs and holds urine or the like is not brought into close contact with the wearer's skin.
And the pants type disposable diaper which formed the space between a wearer's skin and the diaper surface in a wearer's crotch part is proposed.

  For example, Patent Document 1 discloses a pants-type disposable diaper having a waist opening and a pair of leg openings, and an elastic member is stretched on the leg opening to form a leg gather. A pants-type disposable diaper is disclosed in which the distance between the elastic member and the elastic member is gathered without being affected by the rigidity of the absorbent body when worn. According to the pants-type disposable diaper described in Patent Document 1, the leg gathers form a uniform and effective gather without being affected by the rigidity of the absorbent body. Since it is located away, a space is created between the skin of the crotch and the absorber.

JP-A-4-244152

  In the pants-type disposable diaper described in Patent Document 1, the width of the absorbent body is narrowed at the crotch part in order to increase the distance between the elastic member constituting the leg gather and the absorbent body by 15 mm or more, and the absorption performance inside the leg gather is reduced. There is a risk of leakage and leakage from the width direction of the crotch.

  Accordingly, an object of the present invention is to provide a disposable diaper having excellent anti-leakage properties as well as anti-curvature properties.

The present invention is a disposable diaper comprising an absorbent main body including an absorbent core, and an outer packaging material disposed on the non-skin contact surface side of the absorbent main body,
The absorptive core is divided into a central core located at the center in the width direction of the diaper and a pair of side cores located on both sides of the absorbent core at least at the diaper crotch. By providing a disposable diaper in which each of the pair of side cores is provided with a rigid material made of a heat-fusible fiber inside the thickness direction, the above-mentioned purpose is achieved. Achieved.

  According to the disposable diaper of this invention, it is excellent in leakage prevention property with the prevention of stuffiness.

  Hereinafter, as a preferred embodiment of the disposable diaper of the present invention, a pants-type disposable diaper will be described with reference to FIGS.

A pants-type disposable diaper (hereinafter also referred to as a diaper) 1 according to the present embodiment includes an absorbent main body 5 including a liquid-permeable surface sheet 2 and a liquid-retaining absorbent core 4 as shown in FIGS. And the outer packaging material 10 disposed on the non-skin contact surface side of the absorbent main body 5.
Moreover, in the diaper 1 of this embodiment, the absorptive core 4 is symmetrically located in each of the both sides of the hourglass-type center core 41 located in the width direction center part of the diaper 1 in the diaper crotch part C at least. The pair of side cores 42, 42 is divided into a pair of side cores 42, 42, and each of the pair of side cores 42, 42 stands up along the wearer's crotch at the time of wearing. A rigid material 422 made of heat-fusible fibers is disposed inside the thickness direction.

  The diaper 1 is divided into an abdominal side A disposed on the wearer's abdomen, a back side B disposed on the back of the wearer, and a crotch C positioned therebetween. The ventral portion A, the back portion B, and the crotch portion C are arranged in the longitudinal direction (in FIG. Each region is divided into three regions so that the total length in the vertical direction is divided into approximately three equal parts.

In addition, in this specification, the "non-skin contact surface side" is the side arranged on the opposite side to the wearer's skin side during wearing, among the front and back sides (surfaces) of each member such as the absorbent main body. (Surface). In addition, hereinafter, the term “skin contact surface side” may be used, and this is the side (surface) that is arranged on the skin side of the wearer when wearing, out of the front and back sides (surface) of each member. It is.
The “longitudinal direction” is a direction parallel to the long side of each member. Hereinafter, the phrase “width direction” may be used, which is a direction orthogonal to the longitudinal direction.

As shown in FIG. 2, the absorbent main body 5 has a vertically long rectangular shape, and the hot melt is formed so that the longitudinal direction thereof coincides with the longitudinal direction of the diaper 1 and extends from the ventral side A to the back side B. The outer packaging material 10 is joined to the central portion in the width direction by a known joining means such as a mold adhesive.
The outer packaging material 10 has both side edges of the portion located on the ventral side A and both side edges of the portion located on the back side B, which are connected to each other by known joining means such as heat sealing, high frequency sealing, and ultrasonic sealing. It joins and a pair of side seal part is formed by this. Moreover, as shown in FIG. 1, the waist opening part 7 and a pair of leg opening parts 8 and 8 are formed in the diaper 1 by the joining.

  The absorbent core 4 in the diaper 1 of the present embodiment is generally vertically long (250 to 500 mm in length, 80 to 200 mm in width) along the longitudinal direction of the diaper 1 as a whole, as shown in FIGS. ) In a rectangular plan view, and the whole is covered with a water-permeable covering sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric.

  As shown in FIG. 2, the absorbent core 4 is disposed on the diaper 1 such that the side cores 42 and 42 are disposed at least on the crotch part C. The absorbent core 4 is arranged such that a pair of side cores 42 and 42 are arranged in the crotch part C, and one longitudinal direction F of the central core 41 is located in the ventral side A, and the other longitudinal part R is It arrange | positions so that it may be located in the back part B. In addition, the longitudinal direction one part F, the longitudinal direction other part R, and the longitudinal direction center part M pinched | interposed into these both parts divide the full length of the longitudinal direction into about 3 equally in the absorptive core 4 of the state shown in FIG. Thus, each area is divided into three areas.

In the absorbent core 4, each of the pair of side cores 42, 42 is formed by laminating an absorbent material 421 made of hydrophilic fibers and a rigid material 422 as shown in FIGS. 1 to 3, particularly FIGS. 3A and 3C. Has been formed. The shape of the rigid member 422 in plan view is a vertically long rectangular shape, and the longitudinal direction thereof coincides with the longitudinal direction of the diaper 1.
The rigid material 422 serves as a support body that maintains the upright state of the side core 42 when the diaper 1 is worn. As shown in FIG. 3C, the rigid material 422 is a non-skin contact of the absorbent material 421. It is laminated on the surface side. When the absorbent 421 made of hydrophilic fibers absorbs the liquid and becomes wet, the rigidity decreases. On the other hand, the rigid member 422 having a certain rigidity even in a wet state supports the absorbent member 422 and maintains the side core 42 standing up as shown in FIGS.
Therefore, the rigid material 422 preferably has a shape that supports the absorbent material 421. In the present embodiment, the planar shape of the rigid material 422 is substantially the same as that of the absorbent material 421.

The dimensions of the rigid material 422 will be described in detail. The rigid material 422 has a length (length in the longitudinal direction) L1 (see FIG. 3) of preferably 100 to 300 mm, more preferably 130 to 260 mm, and its width. W1 (refer FIG. 3) becomes like this. Preferably it is 20-50 mm, More preferably, it is 25-40 mm.
The length L1 of the rigid member 422 is preferably set to 100 mm or more in order to prevent the side core 42 from rising and prevent stuffiness and to prevent leakage in the width direction at the crotch part in the front-rear direction. The length L1 of the rigid member 422 is preferably 300 mm or less in order to obtain a good wearing feeling at the crotch part. In addition, it is preferable that the width W1 of the rigid member 422 is 20 mm in order to prevent the side core 42 from being raised and prevent stuffiness and leakage in the width direction at the crotch part. The width W1 of the rigid member 422 is preferably 50 mm or less in order to obtain a good wearing feeling at the crotch part.
The width W1 is a value measured on the center line in the width direction that bisects the length of the central core 41 in the longitudinal direction.

  The central core 41 includes a T-shaped upper core 411 and an hourglass-shaped lower core 412 larger than the upper core 411, and the upper core 411 extends from one longitudinal part F of the lower core 412 to the longitudinal central part M. It is overlapped on the skin contact surface side of the lower core 412 (in the vicinity of the urination point).

  One part in the longitudinal direction and the other part in the longitudinal direction of the absorbent material 421 are connected to each other at one longitudinal part (abdominal side part) F and the other longitudinal part (back side part) R of the lower core 412. Between the central core 41 and the pair of side cores 42, 42, there are formed cut-out portions 43, 43 each having a hollow shape. In the crotch portion C, the lower core 412 and the pair of side cores 42, 42, It is separated from 42. As shown in FIG. 3A, the separation part 43 has an arcuate shape extending in the longitudinal direction of the absorbent core 4. More specifically, in the separation part 43, the side edge from the side core 42 side has a linear shape, and the side edge from the center core 41 has a convex shape inward in the diaper width direction. It is preferable that the length of the separation portion 43 coincides with the length L1 of the rigid material 421. The length of the rigid material L1 coincides with the length of the separation portion 43 and may be shorter.

The above-mentioned rigid material 422 is made of a heat-fusible fiber from the viewpoint of maintaining the standing state of the side core 42 against the deterioration of the rigidity of the side core 42 due to liquid absorption and the deformation caused by the movement of the diaper wearer. It is preferable that they are formed from an airlaid nonwoven fabric in which a network structure is formed by heat fusion.
The nonwoven fabric produced by the air laid method uses air laid air to disperse, entangle and fuse heat fusible fibers, and thus has high rigidity and excellent bulkiness.

The maximum load value of the bulk softness of the rigid material 422 in the wet state is preferably 2 to 10N, particularly 5 to 8N. The maximum load value of bulk softness is a measure of the height of rigidity of the rigid material 422. The larger the maximum load value of the bulk softness, the higher the rigidity of the rigid material 422. By setting the maximum load value of the bulk softness of the rigid material 422 in the wet state to 2N or more, the rising state of the side core 42 is maintained against the deterioration of the rigidity of the side core 42 due to liquid absorption and the deformation due to the movement of the diaper wearer. Is done. On the other hand, the favorable softness | flexibility and fitting property of the side core 42 are ensured by the maximum load value of the bulk softness in a wet state being 10 N or less.
In addition, the maximum load value of the bulk softness of the rigid member 422 in the dry state is preferably 12 N or less from the viewpoint of manufacturing and obtaining a good wearing feeling in the crotch.

A rigid body 422 and an absorbent material 421 are laminated to produce a laminated body, and the laminated body is covered so as to be wrapped with a mount and a water-permeable nonwoven fabric (such as an air nonwoven fabric) to produce a side core 42. The maximum load value of the bulk softness in the wet side core 42 is preferably 5 to 15N, particularly 7 to 12N.
Further, the maximum load value of the bulk softness of the side core 42 in the dry state is preferably 18 N or less from the viewpoint of manufacturing and obtaining a good wearing feeling in the crotch part.

  Here, in the wet state of the rigid material 422, physiological saline (about 8%) having a weight four times the weight of the rigid material 422 was impregnated and applied to the entire surface and both surfaces of the measured rigid material by spraying. State. In addition, the dry state of the rigid material 422 does not mean only the state in which the rigid material 422 does not contain any water before using the diaper 1, but the water under the humidity and temperature under normal storage conditions. Also included is a substantially dry state in which the rigid material 422 exists in an equilibrium adsorption state.

<Measurement method>
The maximum load value of bulk softness is measured by the following method. It is measured by a compression tester (Tensilon RTA -100: Orientec). The rigid member 422 is rounded in a rectangular shape having a dimension of 150 mm in the longitudinal direction and 25 mm in the width direction so that the long side thereof is in the circumferential direction to form a cylinder having a height of 25 mm and a circumference of 140 mm. A cylinder is installed in a Tensilon tensile tester, and the cylinder is compressed in a compression mode of 10 mm / min. Measure the compression load and use the maximum value as the maximum load value for bulk softness.
The maximum load value of the bulk softness of the side core 42 is measured in the same manner as the rigid material 422. However, the laminated body of the part except the elastic member 9 shown in FIG. 4 is measured.

Further, the compression recovery rate (RC value) of the rigid material 422 in a wet state is preferably 50 to 80%, particularly preferably 55 to 75%. By setting the compression recovery rate (RC value) of the rigid material 422 in the wet state to 50% or more, the rising state of the side core 42 is recovered and maintained against deformation due to the movement of the diaper wearer. Further, when the compression recovery rate (RC value) of the rigid member 422 in the wet state is set to 80% or less, a good wearing feeling in the crotch part can be obtained.
<Measurement method>
The RC value of compression recoverability is measured by the following method. In a wet state, measured with a compression tester (KES G5: KATO TECH) under measurement conditions of measurement load: 5.0 gf / m ² , upper limit load: 50 gf / m ² , compression speed: 0.002 cm / sec The The size of the measurement site may be arbitrarily set according to the size of the rigid material 422.

The rigid material 422 in a wet state preferably has a repulsive force of 1 to 6 N, particularly 2 to 5 N when compressed by 50% during bulk softness measurement. It is preferable that the repulsive force is within such a range for the same reason as described in the compression recovery rate described above.
<Measurement method>
Here, the repulsive force when compressed by 50% is measured by the following method. When measuring the bulk softness with a compression tester (Tensilon RTA-100: Orientec Co., Ltd.), the measurement rigid material 422 is compressed to 50% (12.5 mm) of the height 25 mm, and the load value at that time is taken.

Furthermore, the basis weight of the rigid material 422 in the dry state is preferably 50 to 200 g / m ² , particularly 80 to 160 g / m ² . It is preferable that the basis weight of the rigid material 422 in the dry state is 50 g / m ² or more in order to secure the above-described physical property values. Moreover, it is preferable that the basis weight of the rigid material 422 in the dry state is 200 g / m ² or less from the viewpoint of manufacturing and obtaining a good wearing feeling in the crotch.

Furthermore, the thickness of the rigid member 422 in the dry state is preferably 1 to 6 mm, particularly 2 to 5 mm. The thickness of the rigid member 422 in the dry state is preferably 1 mm or more in order to secure the above-described physical property values. In addition, it is preferable that the thickness of the rigid member 422 in the dry state is 6 mm or less from the viewpoint of manufacturing and obtaining a good wearing feeling at the crotch.
<Measurement method>
For example, the thickness is measured under a load of about 2.5 g / cm ² by placing a measurement plate (weight: 62.3 g / 5 cm × 5 cm square) on the rigid material 422 by a table thickness gauge manufactured by Keyence.

  The diaper 1 of the present embodiment will be further described. As shown in FIG. 2, elastic members 9 are arranged along both side edges of the water-absorbent core 4, and the elastic members 9 contract when worn. The pair of side cores 42, 42 stands up toward the wearer's skin side. More specifically, a pair of elastic members 9 for starting up the side core 42 of the absorbent main body 5 are arranged in a stretched state along both side edges in the longitudinal direction of the absorbent core 4. As shown in FIG. 4, the absorbent main body 5 is configured such that both side portions 52 and 52 (side cores 42 and 42) in the crotch portion C stand up.

As shown in FIG. 4, the top sheet 2 has a region on the skin contact surface side of the absorbent core 4, a region on both side edges in the width direction of the absorbent core 4, and a non-skin contact surface side of the absorbent core 4. Covers the vicinity of both sides of the diaper width direction.
Further, as shown in FIG. 2, leak-proof cuffs 6 and 6 are formed on both sides of the absorbent main body 5. The leak-proof cuff 6 includes a leak-proof cuff forming sheet 60 joined to the absorbent main body 5, an elastic member 61 for forming a leak-proof cuff fixed in the vicinity of the free end of the leak-proof cuff forming sheet 60, And an elastic member 62 for attracting the leak-proof cuff fixed in an extended state between the fixed end and the free end of the leak-proof cuff 6.

  As shown in FIG. 4, the leak-proof cuff 6 can stand at least at the crotch part C. Near the free end of the leak-proof cuff 6 (the folded end of the leak-proof cuff forming sheet 60), a plurality of leak-proof cuff forming elastic members 61 are arranged in the width direction of the absorbent main body 5, The sheet 60 for leak-proof cuff formation (leak-proof cuff 6) is fixed over the entire longitudinal direction.

  The leak-proof cuff pulling elastic member 62 includes a leak-proof cuff forming sheet 60 (leak-proof cuff 6) between the leak-proof cuff forming elastic member 61 and the main body joint fixing portion 67 in the leak-proof cuff 6. It is arranged over the entire longitudinal direction. Further, the leakage preventing cuff pulling elastic member 62 is provided at a position outside the diaper width direction with respect to the elastic member 9 for raising the side core in the leakage preventing cuff 6 when the diaper 1 is deployed.

In the diaper 1 of the present embodiment, as shown in FIG. 4, a liquid-impermeable or water-repellent back sheet 3 is joined to the skin contact surface side of the outer packaging material 10 by a joint fixing portion 13. The leakproof cuff forming sheet 60 and the absorbent main body 5 are sequentially joined to the skin contact surface side. The back sheet 3 has a vertically long rectangular shape having substantially the same dimensions as the absorbent main body 5, and the longitudinal direction thereof coincides with the longitudinal direction of the diaper at the same position as the absorbent main body 5 (the central portion in the width direction of the outer packaging material 10). It is arranged.
The back sheet 3 is bonded and fixed to the non-skin contact surface side of the leakproof cuff forming sheet 60 so as to cover almost the entire region of the absorbent main body 5 on the non-skin contact surface side.

  The front surface sheet 2 is bonded and fixed to the back surface sheet 3 and the leak-proof cuff forming sheet 60 by bonding means such as heat sealing at both end portions thereof to form bonded fixing portions 67 and 67. Moreover, as for the surface sheet 2, the part of the skin contact surface side and the non-skin contact surface side is joined in the separation part 43. FIG.

  As shown in FIGS. 2 and 4, the outer packaging material 10 includes two outer packaging material forming sheets 11 and 12 and elastic members at respective portions fixed between the two sheets. Between the two outer packaging material forming sheets 11 and 12, a waist elastic member 71 that forms a waist gather at the periphery of the waist opening 7, and a leg elastic that forms a leg gather at the periphery of the leg opening 8 A waistline elastic member 91 that forms a waistline gather in a state of being divided into a member 81 and a waistline portion D (a region from a position spaced 20 mm downward from the peripheral edge of the waist opening 7 to the upper end of the leg opening 8). However, they are bonded and fixed by bonding means such as a hot-melt adhesive in the stretched state.

  The outer packaging material forming sheets 11 and 12 are both made of a breathable nonwoven fabric. Of these two sheets, the sheet 11 positioned on the non-skin contact surface side extends in the longitudinal direction from the front and rear end edges (both end edges in the longitudinal direction) of the sheet 12 positioned on the skin contact surface side. Each of the extended portions covers the front and rear ends (both ends in the longitudinal direction) of the absorbent main body 5 after the absorbent main body 5 is disposed on the sheet 12 of the outer packaging material 10. Thus, it is folded and bonded to the absorbent main body 5 side.

Next, the material constituting each part of the diaper 1 of the present embodiment described above will be described. As the heat-fusible fiber constituting the rigid material 422 in the side core 42, polyethylene (PE), polypropylene (PP), polyethylene -Propylene copolymer, polyethylene terephthalate (PET), polyester such as polybutylene terephthalate, polyethylene terephthalate-ethylene isophthalate copolymer, polyamide ethylene acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid Examples thereof include fibers comprising a copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-methyl acrylate-acrylic terpolymer. A core-sheath type composite fiber or a side-by-side type composite fiber made of a combination of these thermoplastic polymer materials can also be used. The thickness of the heat-fusible fiber is preferably about 1.7 to 50 dtex in order to impart physical properties such as rigidity within the above-described range to the rigid member 422 composed of the fusible fiber. Moreover, it is also preferable that the heat-fusible fiber has crimps from the viewpoint of increasing the compression elastic modulus and repulsive force of the rigid material 422.
If the rigid material 422 made of the heat-fusible fiber has a physical property value such as rigidity within the above-mentioned range, the heat-fusible fiber has either a hydrophobic property or a hydrophilic property. Also good. In addition, it is preferable that the heat-fusible fiber has hydrophilicity because liquid absorption retention is imparted to the rigid material.
Further, the rigid material may contain some fibers other than heat-fusible fibers such as pulp or rayon.

Moreover, as a forming material of the absorbent material 421 made of hydrophilic fibers, which is another member forming the side core 42, a fiber aggregate made of pulp fibers, continuous fibers (tow), or the like can be used. As the absorbent material 421, it is also preferable to use a material composed of the fiber assembly and a water-absorbing polymer (mixed product of water-absorbing polymer and fiber material). Examples of fibers constituting the fiber assembly include hydrophilic fibers such as pulp fibers, rayon fibers, cotton fibers, and cellulose acetate, polyolefin fibers such as polyethylene and polypropylene, and condensation fibers such as polyester and polyamide. it can. Examples of water-absorbing polymers include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, cross-linked sodium polyacrylate, (starch-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride) copolymer. Examples thereof include a polymer and a saponified product thereof, and polyaspartic acid. The water-absorbing polymer and the fiber can be used alone or in combination of two or more.
As a material for forming the central core 41 in the water absorbent core 4, the same material as the absorbent material 421 can be used.

  In addition, as the material for forming the top sheet 2, the back sheet 3, the leak-proof cuff forming sheet 60, and each elastic member, various materials used in conventional absorbent articles can be used without particular limitation.

The stuffiness prevention and leakage prevention mechanism in the diaper 1 of this embodiment is as follows.
When the diaper 1 is attached to an infant, for example, the elastic members 9 and 9 disposed along both side edges of the water-absorbent core 4 are contracted, and as shown in FIG. The pair of side cores 42, 42 faces the wearer's skin side and stands substantially perpendicular to the central core 41. As the pair of side cores 42 and 42 stand, a pocket-shaped space P is formed between the wearer's skin and the central core 41 at the crotch portion of the wearer.
By forming the space P in the crotch portion, it is possible to prevent the wearer's skin and the central core 41 from coming into close contact with each other via the topsheet 2. The air in the space P mainly moves through the gap between the abdominal part A or the back part B and the wearer's skin due to temperature differences inside and outside the diaper, or movements such as breathing and walking of the wearer. And it replaces with the outside air from the waist opening 7. That is, since air in the space P circulates, an increase in humidity in the diaper 1 is suppressed, and stuffiness is prevented. 5 shows only one side of the diaper 1 and the wearer, the same applies to the other side.

Moreover, when the diaper 1 is worn, the side core 42 becomes wet due to excretion of urine and the like. If the side core 42 is formed only from the absorbent material 421, the absorbent material 421 made of hydrophilic fibers such as pulp fibers loses its rigidity in a wet state, and the side core 42 cannot maintain its upright state. Fall down. As a result, the central core 41 is at least partially in close contact with the wearer's skin via the topsheet 2.
On the other hand, according to the diaper 1 of the present embodiment, since the rigid material 422 is arranged together with the absorbent material 421 on the side core 42, the rigid material 422 maintains a certain rigidity even when the side core 42 is in a wet state. Therefore, the absorbent material 421 is supported and the side core 42 is prevented from falling down. As a result, the space P continues to be maintained in the wearer's crotch even when the side core 42 is in a wet state, so that an increase in humidity in the diaper 1 is suppressed, and stuffiness is effectively prevented. Moreover, it is prevented that a wearer's skin and the center core 41 contact | adhere through the surface sheet 2. FIG.

  Furthermore, even if the wearer of the diaper stands, sits down, or moves, the side core 42 is deformed, so that the rigid material 422 supports or recovers the standing state, so that the space P is maintained. Continue to be.

  Furthermore, as described above, since the standing state of the pair of side cores 42 and 42 is maintained by the rigid material 422, lateral leakage in the width direction is effectively prevented in the crotch portion C. Since the excreted urine and loose stool can be held in the pocket-shaped space P formed in the crotch part, the leakage preventing effect is further enhanced by the holding effect.

According to the disposable diaper of this embodiment mentioned above, the following effects are produced.
As shown in FIG. 5, since the leak-proof cuff 6 is provided with an elastic member 62 for pulling the leak-proof cuff, the elasticity for forming the leak-proof cuff in the leak-proof cuff 6 by the contraction force of the elastic member 62. A region between the free end where the member 61 exists and the exterior body joint fixing portion 13 is pulled toward the wearer's suspension. Therefore, particularly the standing end side of the side core 42 is pulled toward the wearer's suspension side through the surface sheet 2 joined to the leakage prevention cuff forming sheet 60, and the standing state is reinforced, and it becomes easy to follow the suspension. . Furthermore, when the side core 42 is pulled to the suspension side, the central core 41 is also pulled outward in the width direction, and the shape of the central absorbent body 41 is stabilized. As a result, a clean feeling at the crotch is improved, and leakage prevention performance is also improved.

The disposable diaper of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
For example, in the disposable diaper 1 of this invention, the absorptive core 4 may have a form as shown to Fig.6 (a)-(d). In the absorbent core 4 shown in FIG. 6A, the absorbent material 421 in the side core 42 is not connected to the lower core 412 in the central core 41, and both longitudinal ends of the separating portion 43 are open. In the absorbent core 4 shown in FIG. 6B, the absorbent material 421 is connected to one side in the longitudinal direction of the lower core 412, but is not connected to the other side in the longitudinal direction. The other end in the direction is open. In the absorbent core 4 shown in FIG. 6 (c), the cut-out portions 43 are formed along both side edges in the longitudinal direction of the lower core 412 and between the front and rear end portions. On both sides, narrow and vertically long absorbent materials 421 and 421 having the same length are arranged separately from the lower core 412. As for the absorptive core 4 shown in FIG.6 (d), the separation part 43 has a vertically long rectangular shape. The absorbent core 4 shown in FIGS. 6A to 6D is configured in the same manner as the absorbent core 4 of the present embodiment except for the above.

In the present embodiment, the shape of the rigid member 422 in plan view is substantially the same as that of the absorbent member 421. However, the rigid member 422 has a certain rigidity that can maintain the standing state of the side core even when the rigid member 422 is wet. For example, the plan view shape of the rigid member 422 may not be substantially the same as the absorbent member 421.
Furthermore, in the present embodiment, the rigid material 422 is formed of an air laid nonwoven fabric, but the rigid material 422 is formed by laminating another nonwoven fabric made of heat-fusible fibers, such as an air-through nonwoven fabric, to increase rigidity. There may be.

  The disposable diaper of this embodiment may be a pants type or a tape type, and may be an infant diaper, an adult diaper, or an adult urinary incontinence diaper.

  Hereinafter, the underpants type disposable diaper of this invention is further demonstrated using an Example. However, the scope of the present invention is not limited to such examples.

Airlaid non-woven fabric (made by Oji Kinocross Co., Ltd., product name: kitchen airlaid, composition of heat-fusible fiber: PET / PET, fiber thickness: 22 dtex 80% as a material for forming the rigid material 422 with /2.2dtex 20%), to prepare a rigid material 422 having a basis weight of 110g / m ^2, and as the material for forming the absorbent material 421, to produce the absorbent material 421 having a basis weight of 118 g / m ² using a pulp fiber Next, a laminate was prepared by laminating both materials, and the laminate was covered so as to be wrapped with a mount and a water-permeable nonwoven fabric (such as an air-through nonwoven fabric) to produce a side core 42. Example 1 was obtained. The absorbent material 421 is not connected to the lower core 412 and only the side core 42 is produced. The length of the side core 42 was 150 mm, and the width was 25 mm. The maximum load value of bulk softness in the wet state of Example 1 was 980 gf (9.6 N).

  Using the side core 42 of Example 1, the pants-type disposable diaper shown in FIG. 1 and FIG. The absorbent material 421 was manufactured integrally with the lower core 412.

  A side core 42 having only the absorbent 421 was produced in the same manner as in Example 1 except that the rigid material 422 was not provided. The maximum load value of bulk softness in the wet state of Comparative Example 1 was 360 gf (3.5 N).

A side core 42 was produced in the same manner as in Comparative Example 1 except that the basis weight of the pulp fiber was 188 g / m ^2, and Comparative Example 2 was obtained. The maximum load value of bulk softness in the wet state of Comparative Example 2 was 450 gf (4.4 N).

A side core 42 was produced in the same manner as in Example 1 except that a urethane foam resin was used as a material for forming the rigid material 422 and a rigid material 422 having a basis weight of 55 g / m ² was produced. The maximum load value of bulk softness in the wet state of Comparative Example 3 was 430 gf (4.2 N).

As a material for forming the rigid material 422, a hydrophilic airlaid nonwoven fabric (product name: hydrophilic airlaid (high cloth) manufactured by Oji Kinocloth Co., Ltd., heat-fusible fiber / pulp fiber / binder = 17/80/3 mass%) is used. A side core 42 was produced in the same manner as in Example 1 except that a rigid material 422 having a basis weight of 160 g / m ² was produced. The maximum load value of bulk softness in the wet state of Comparative Example 4 was 460 gf (4.5 N).

  A pants-type disposable diaper was produced as Comparative Example 5 in the same manner as in Example 2 except that the side core 42 of Comparative Example 1 was used.

  A pants-type disposable diaper was produced as Comparative Example 6 in the same manner as in Example 2 except that the side core 42 of Comparative Example 4 was used.

[Evaluation of bulk softness]
By the method described above, the maximum load value of bulk softness in the dry state and the wet state was measured using the side cores 42 of Example 1 and Comparative Examples 1 to 4, respectively. Here, in the wet state of the rigid material 422, physiological saline (about 8%) having a weight four times that of the prepared side core 42 is impregnated and applied from the absorbent material 421 side of the measurement side core 42 to the front surface by spraying. It is in the state.
The measurement results are shown in FIG.
Compared with Comparative Examples 1 to 4, Example 1 has better rigidity in a dry state and a wet state, particularly in a wet state.

[Evaluation of humidity in diapers]
The diaper of Example 2 and Comparative Examples 5 and 6 were placed on the warm water circulation infant waist model shown in FIGS. 8A and 8B, and the humidity in the diaper was measured. In the warm water circulation infant waist model, warm water circulates between a thermostat (not shown) and the temperature of the model surface is kept constant. In this evaluation, the temperature of the model surface was 40 ° C. Further, during the period from the start of evaluation to 120 minutes, 200 g of artificial urine is injected into the diaper every 30 minutes by the tube 101, and the humidity sensor 102 shown in FIGS. 8 (a) and (b) In the diaper, the change over time in the humidity of the model surface in the vicinity of excretion and the hip was measured. The measurement results are shown in FIG.

Compared with Comparative Examples 5 and 6, the present Example 2 maintains the model surface with a lower humidity in the excretory part and the hip part of the model, and the present Example 2 is superior in anti-dampness. I understand that.
This model is made of a transparent material. When the diapers of Example 2 and Comparative Examples 5 and 6 are put on the model, the diaper is pulled upward and pulled to a place where it cannot move any further. In the crotch portion of each model before this evaluation, a pocket-shaped space was formed between the surface of the model and the surface sheet of the diaper.
At the end of this evaluation, in the diaper of Example 2, a pocket-like space was maintained between the surface of the model and the top sheet of the diaper in the crotch portion of the model. On the other hand, in the diapers of Comparative Examples 5 and 6, the top sheet of the diaper was at least partially in close contact with the surface of the model. This is because in the wet state of the diaper, the side core 42 with reduced rigidity has sag and the standing state has collapsed.

[Leakage evaluation]
An infant's waist model (artificial urine can be injected from the crotch and made of a transparent material) was worn with the diapers of Example 2 and Comparative Examples 5 and 6, and the crotch leakage value was measured by the following method. .
When attaching the diaper to the above model, put a finger between the model crotch part and the crotch part of the diaper undercarriage gather and push the solid gather inward so as not to touch the elastic member 61 in the crotch part. The leak-proof cuff 6 and the side core 42 were lightly pushed from the outside between the elastic member 61 and the elastic member 62 of the leak-proof cuff 6 with the finger, and the finger was released after the side core 42 was inclined by about 45. After that, the case where the side core 42 stands up again is described as “returned” in Table 1, and the state of being tilted is described as “falling down”.
As for the installation posture, the model was first turned sideways by 90 degrees and then tilted to the back side by 45 degrees. 40 g of artificial urine was injected through the tube at a rate of 5 g / sec, and it was visually checked for leakage after injection. If there was no leakage, another 40 g was injected after 5 minutes, and this was repeated until it leaked. The total amount of artificial urine injected at the time when urine leakage was observed from the leak-proof cuff 6 was defined as the crotch leakage value. The larger the crotch leakage value, the better the leakage prevention property. Further, the standing state of the side core 42 at the time when urine leakage was observed was recorded.

  The measurement results are shown in Table 1. It can be seen that the present Example 2 is superior in leakage prevention properties as compared with Comparative Examples 5 and 6. This is presumably because the side core 42 that is inclined before the measurement stands up during the measurement and the state is maintained because the rigidity of the side core 42 is high.

FIG. 1 is a perspective view showing a pants-type disposable diaper as an embodiment of the present invention. FIG. 2 is a plan view showing a state in which the diaper shown in FIG. 1 is separated and expanded by a side seal part, and the elastic member of each part is expanded and expanded in a planar shape, partially broken. 3A and 3B are diagrams showing an absorbent core in the diaper shown in FIG. 1, wherein FIG. 3A is a plan view, FIG. 3B is a cross-sectional view taken along line BB in FIG. 1A, and FIG. It is sectional drawing. 4 is a cross-sectional view schematically showing a cross section taken along line VV of FIG. FIG. 5 is a schematic half sectional view showing a wearing state of the diaper shown in FIG. Fig.6 (a)-(d) has shown the underpants type disposable diaper of other embodiment of this invention, and the form of an absorptive core differs, respectively. FIG. 7 shows the measurement result of the bulk softness. 8 (a) and 8 (b) are perspective views showing a warm water circulation infant waist model used for measuring the humidity in the diaper, (a) showing the ventral side, and (b) showing the dorsal side. Yes. 9A and 9B show the diaper humidity measurement results, FIG. 9A shows the humidity of the excretory part, and FIG. 9B shows the humidity of the hip part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent core 41 Central core 411 Upper core 412 Lower core 42 Side core 421 Absorbent material 422 Rigid material 43 Cut off part 5 Absorbent main body 6 Leak-proof cuff 60 Leak-proof cuff formation Sheet 61 Elastic member for forming leak-proof cuff 62 Elastic member for attracting leak-proof cuff 67 Joint fixing portion 7 Waist opening portion 8 Leg opening portion 9 Elastic member 10 for raising side core Outer packaging material 13 (Outer packaging material) Joint fixing portion 100 Hot Water Circulation Infant Lumbar Model 101 Tube 102 Humidity Sensor A Ventral Side B Back Side C Crotch P Space

Claims (5)

A disposable diaper comprising an absorbent main body including an absorbent core and an outer packaging material disposed on the non-skin contact surface side of the absorbent main body,
The absorptive core is divided into a central core located at the center in the width direction of the diaper and a pair of side cores located on both sides of the absorbent core at least at the diaper crotch. It is designed to stand along the inseam of the
Each of the pair of side cores is a disposable diaper in which a rigid material made of heat-fusible fibers is arranged inside in the thickness direction.   The disposable diaper according to claim 1, wherein each of the pair of side cores is formed by laminating an absorbent material made of hydrophilic fibers and the rigid material.   The disposable diaper according to claim 2, wherein the rigid material is laminated on the non-skin contact surface side of the absorbent material.   The disposable diaper according to any one of claims 1 to 3, wherein the rigid material is formed of an airlaid nonwoven fabric. The elastic member is distribute | arranged along the both-sides edge part of the said water absorptive core, When this elastic member shrink | contracts, it is made for a pair of said side core to stand. Disposable diapers.

Images