JP3801449B2 - Absorbent articles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorbent article such as a sanitary napkin, an incontinence pad, and a panty liner having a middle and high portion protruding in a convex shape on a surface directed toward the wearer's skin.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, a protruding portion is formed in a portion disposed on the excretion portion of the wearer on a surface directed to the wearer's skin side (hereinafter also referred to as a skin contact surface), thereby increasing the spot absorbability and absorbing liquid. of or preventing relapse, sanitary napkins having improved leakage prevention effect to improve the adhesion have been proposed to the skin (actual Hei 6-15621 Patent Publication).
[0003]
However, the protruding portion of the conventional napkin is a two-layer absorbent body in which a small upper layer absorber is laminated on a large lower layer absorber, so that the small upper layer absorber projects upward. Therefore, a large step is generated at the peripheral edge of the protruding portion, and some wearers may feel uncomfortable at the time of wearing or may feel uncomfortable in appearance.
[0004]
Moreover, the side part of the lower layer absorbent body that extends outward from the side edge of the upper layer absorbent body is bent to the skin contact surface side during or during wearing, and the cross-sectional shape of the napkin is deformed into a W shape. Depending on the situation, leakage may occur, and the fit and wearing feeling may deteriorate.
[0005]
Therefore, the object of the present invention is to prevent the wearer from feeling uncomfortable or uncomfortable, and to prevent the wearer from being deformed into a W-shaped cross section, and has excellent leakage prevention. It is an object to provide an absorbent article such as a sanitary napkin, an incontinence pad, and a panty liner that can surely obtain the performance, fit, and wearing feeling.
[0006]
[Means for Solving the Problems]
The present invention comprises a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent article interposed between both sheets, and in an absorbent article formed substantially vertically, the absorbent is An upper layer absorber, and a lower layer absorber formed smaller than the upper layer absorber and laminated on the back side of the upper layer absorber , and both side edges of the lower layer absorber on the surface side of the upper layer absorber Grooves are formed in the portions located more outward from each other, the horizontal distance between both side edges of the lower layer absorber and the grooves located outward is 2 to 10 mm, and the upper layer absorber is The bending moment of the portion located on the lower absorber is 0.5 to 60 mN · m, and the upper absorber is an absorbent article in which the portion located on the lower absorber protrudes upward. The above-mentioned purpose is achieved by providing
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on a preferred embodiment thereof.
The sanitary napkin 1 according to the first embodiment includes a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and an absorbent body 4 interposed between both sheets, as shown in FIGS. However, it is formed substantially vertically.
[0008]
Each of the top sheet 2 and the back sheet 3 has a vertically long shape in which both side edges are formed in an arc shape and both side edges are formed in a straight line in plan view, and extends outward from the peripheral edge of the absorber 4. They are joined to each other at the peripheral edge.
An adhesive is applied to the lower surface side of the back sheet 3, and a fixing portion (not shown) for fixing the napkin 1 to an underwear such as shorts is formed.
[0009]
The absorbent body 4 in the napkin 1 of the first embodiment includes an upper layer absorbent body 41 and a lower layer absorbent body 42 that is formed smaller than the upper layer absorbent body 41 and is laminated on the back surface side of the upper layer absorbent body 41.
The upper layer absorber 41 has a vertically long shape in which both end edges are formed in an arc shape and both side edges are formed in a straight line shape. The lower layer absorbent body 42 is formed in an oval shape, and has a flat area (area in plan view) smaller than that of the upper layer absorbent body 41, and a central portion (longitudinal direction and width direction) of the upper layer absorbent body 41 in the longitudinal direction and the width direction. Are laminated on the back surface side of the upper-layer absorber 41 in a portion excluding the vicinity of both end portions of the upper layer absorber 41.
[0010]
Grooves 5 are formed on both the left and right sides in the width direction of the portion 41 a corresponding to the lower layer absorber 42 on the surface side of the upper layer absorber 41. That is, the grooves 5 are formed on the surface side of the upper layer absorbent body 41 at portions located outward from both side edges 44 of the lower layer absorbent body 42.
The groove 5 in the napkin 1 according to the first embodiment is formed around the portion 41 a corresponding to the lower layer absorbent body 42 over the entire circumference by pressing from the top sheet 2 side, and both sides of the napkin 1. Is formed in a circular arc shape that is concavely curved outward, and both ends of the napkin 1 are formed in a circular arc shape that is convexly convex outward. The groove 5 as a whole has a vertically long elliptical shape with a central portion constricted.
[0011]
Further, the grooves 5 formed on both sides in the width direction of the portion 41a corresponding to the lower layer absorber 42 have a length extending between both longitudinal edges 43, 43 of the lower layer absorber 42 as shown in FIG. is doing.
The portion 41a corresponding to the lower layer absorber 42 in the upper layer absorber 41 is a portion where the lower layer absorber 42 exists on the back surface side, and is a portion surrounded by a dotted line A in FIG.
Further, along the both side edges in the longitudinal direction of the absorbent body 4, grooves 7 are formed on the left and right sides inside the both side edges. The groove 7 is applied on the upper layer absorbent body 41 by pressing from the upper side of the topsheet, similarly to the groove 5. In FIG. 1, it is linearly formed along both side edges of the absorber. However, like the groove 5, it may be formed in an arc shape that is convexly convex inward in the width direction.
[0012]
The horizontal distance W1 between the side edges 44 of the lower layer absorbent body 42 and the groove 5 on the outer side in the width direction is 2 from the viewpoint of making the peripheral edge of the middle and high parts a gentle surface shape and obtaining excellent fit and wearing feeling. -10 mm . The horizontal distance W1 at the portion where the horizontal distance W1 is minimum (the portion where the groove 5 is closest to the lower layer absorber 42) is the ratio to the width W2 of the upper layer absorber 41 extending from the side edge 44 of the lower layer absorber 42. Is preferably 2 to 60%, more preferably 5 to 30%.
[0013]
In order to obtain excellent spot absorptivity without spreading the absorbed liquid on the top sheet or the absorbent body, the groove 5 pressed against the upper layer absorbent body 41 from the top sheet 2 side is necessary. The depth D (depth from the upper surface of the upper layer absorber 41) D is preferably 1 to 8 mm, and the depth D of the groove 5 is the thickness T4 of the upper layer absorber 41 at a portion adjacent to the groove 5. It is preferable that the ratio with respect to is 30 to 90%, particularly 50 to 80%.
[0014]
Moreover, it is preferable that the width W3 of the groove | channel 5 is 0.5-4 mm from a viewpoint of preventing the discomfort at the time of mounting | wearing.
The width W6 of the groove 7 is also preferably 0.5 to 4 mm from the viewpoint of preventing wearing similarly to the groove 5.
The grooves 7 formed on both sides of the absorbent body not only have the function of preventing the menstrual blood that has spread beyond the groove 5 outward in the width direction when the amount of menstrual blood is large, but also the upper layer absorbent body. The region of the absorber side portions W2 that become the above is difficult to twist when mounted between the crotch, and functions to keep the mounting shape stably convex. That is, the compressive force from the thigh due to the movement of the foot acts on both sides of the absorber, but stress is not concentrated by providing the grooves 5 and 7 in the longitudinal direction in the W2 region on both sides of the absorber. Therefore, it will not be greatly twisted partially.
In order to transmit the compressive force from the thigh to the absorber center from both sides, the absorber center takes a convex shape on the skin side more and fits the excretory part, and the fit is high, It is possible to further enhance the leak prevention effect that is difficult to twist.
As a position where the groove 7 is provided, the distance W7 from the both ends of the absorber is preferably 3 to 20 mm, and the distance W8 from the groove 5 is preferably 3 to 30 mm, particularly preferably 5 to 20 mm.
In addition, the width W4 of the lower layer absorber 42 is preferably 20 to 70% with respect to the width W5 of the upper layer absorber 41, and the length L1 of the lower layer absorber 42 is larger than the total length L2 of the upper layer absorber 41. It is preferably 20 to 80%.
Moreover, it is preferable that the plane area of the lower layer absorber 42 is 3 to 70%, particularly 5 to 30%, of the plane area of the upper layer absorber 41.
[0015]
As shown in FIG. 2, the upper layer absorber 41 has a portion 41 a located on the lower layer absorber 42 protruding upward. And the middle-high part 6 which protruded in the convex curved surface shape in the center part of the skin contact surface P of the napkin 1 is formed of this protruding part 41a. The peripheral portion of the upper layer absorber 41 is at the same height as the lower layer absorber 42 and surrounds the lower layer absorber 42.
[0016]
In the upper layer absorber 41, the bending moment of the portion 41a located on the lower layer absorber 42 is 0.5 to 60 mN · m in terms of the Taber value, and preferably 1 to 30 mN · m.
When the Taber value is 0.5 mN · m or more, excessive deformation of the upper-layer absorber itself can be suppressed, and the upper-layer absorber itself can be prevented from being greatly swung. As a result, even if there is sufficient absorption power, there is no possibility that leakage is likely to occur. In addition, when the Taber value is 60 mN · m or less, the rigidity of the upper-layer absorbent body itself does not become excessively high, so it is possible to prevent the wearer's body from being fitted and a gap from being formed between the body and the body. Furthermore, it is possible to prevent the wearer from feeling uncomfortable, or from damaging the fit / wearing feeling. From such a viewpoint, the Taber value is preferably 1 to 30 mN · m.
[0017]
Here, the bending moment (Taber rigidity value) of the portion 41a located on the lower layer absorber 42 in the upper layer absorber 41 is measured as follows.
From the viewpoint of obtaining a comfortable fit and wearing feeling when worn, it is preferable that the rigidity of the napkin 1 is in the above range. Therefore, the test piece used for the measurement is prepared in the longitudinal direction of the napkin 1.
The upper layer absorbent body 41 is cut into a dimension of 70 mm in the longitudinal direction of the napkin 1 and 38 mm in the width direction, with the center point of the portion 41 a located on the lower layer absorbent body 42 as the center. Using the cut specimen, the bending moment is measured in accordance with the method defined in JIS P8125.
In P8125, the width of the test piece is 38.0 ± 0.2 mm, but the cut out test piece may be a test piece having a width of 30 to 40 mm. In that case, as specified in P8125, the bending moment is converted to a width of 38.0 mm. The auxiliary weight is arbitrarily selected so that the support load scale is in the range of 15 to 85% of the maximum scale.
The bending moment is measured using a Taber stiffness tester. The test piece is attached so that the bending to the skin contact surface P side corresponds to the left bending in the testing machine, and the bending load in both the left and right directions is averaged to obtain the bending moment.
[0018]
Further, the napkin 1 (absorbent article) has a bending moment with respect to the bending to the skin contact surface P side in the width direction (bending in the direction of arrow B in FIG. 2) toward the non-skin contact surface Q side. It is preferably larger than the bending moment for bending (bending in the direction of arrow C in FIG. 2). Since the bending moment toward the skin contact surface P side is larger than the bending moment toward the non-skin contact surface Q side, the napkin 1 (absorbent article) is shown in FIG. As shown in FIG. 4, along the excretion part, it can be easily deformed into a bowl-shaped shape, and the middle and high parts have a gentle shape, so there is no excellent fit or discomfort to the excretion part. A comfortable wearing feeling can be obtained. Furthermore, since both sides of the napkin are not bent to the skin contact surface P side and the cross-sectional shape of the napkin is not deformed into a W shape, the liquid spreading prevention effect by the groove can be obtained more stably and excellent leakage prevention It is possible to exert an effect.
[0019]
Here, the magnitude of the bending moment toward the skin contact surface P side and the bending moment toward the non-skin contact surface Q side are compared by measuring the bending moment by the following method.
[Bending moment for bending toward skin contact surface P]
Using a test piece cut out from the napkin 1, the bending moment is measured according to the method defined in JIS P8125.
Since the napkin 1 takes a bowl-like shape when worn, an excellent fit and wearing feeling can be obtained, so that the bending moment in the width direction of the napkin 1 is important. Therefore, the test piece used for the measurement is prepared with respect to the width direction of the napkin 1.
That is, the width of the napkin 1 is set at two locations in the longitudinal direction so as to include an absorber portion disposed opposite to the excretion portion of the wearer, that is, a portion where the upper layer absorber 41 and the lower layer absorber 42 are laminated. Cut in the direction to obtain a 38 mm wide test piece.
P8125 is based on the width of the test piece of 38.0 ± 0.2 mm, and the length is about 70 mm. When the length of the test piece cut out from the napkin 1 (corresponding to the width of the napkin 1) exceeds 70 mm, a portion exceeding 70 mm (side edge portions of the napkin 1) is cut to obtain a test piece.
The bending moment is measured using a Taber stiffness tester. The original bending moment is obtained by averaging the loads in both the left and right directions. Here, in order to measure the bending moment toward the skin contact surface P side, the bending toward the skin contact surface P side is to the left in the testing machine. Mount the test piece to correspond to the bending of, and measure only the bending load to the left.
[Bending moment for bending toward non-skin contact surface Q]
A test piece is prepared in the same manner as the test piece used for the bending moment measurement for bending toward the skin contact surface P side.
For the bending moment toward the non-skin contact surface Q side, the test piece is mounted so that bending to the non-skin contact surface Q side corresponds to bending to the left in the above tester, and only the bending load to the left is measured. To do.
[0020]
The bending moment toward the skin contact surface P side is preferably 5% or more larger than the bending moment toward the non-skin contact surface Q side.
[0021]
By disposing the lower layer absorbent body 42 in the portion of the wearer's excretion part, the gap between the body and the body is reduced, and in particular, the fit to the excretion part is improved and the excreted liquid is reliably absorbed. Can be made. From such a viewpoint, the lower layer absorber 42 has a thickness (T1) of preferably 2 to 20 mm, particularly preferably 3 to 10 mm, and the thickness of the napkin 1 in the portion where the upper layer absorber 41 and the lower layer absorber 42 are laminated. (T2) and the thickness difference (T5 = T2-T3) between the thickness (T3) of the napkin 1 in the portion where the upper-layer absorber 41 is disposed and the lower-layer absorber 42 is not disposed are 1 to 10 mm, particularly It is preferable that it is 2-8 mm.
[0022]
Moreover, although the upper layer absorber 41 and the lower layer absorber 42 may be bonded by an adhesive or the like, it is preferable that the two are not bonded. By not bonding between the absorbers 41 and 42, the excreted liquid is quickly absorbed without being inhibited by the adhesive interface formed by applying the adhesive. Moreover, it becomes easy to take the convex shape to the skin contact surface at the time of wear by having the freedom degree of both interfaces because the upper layer absorber and the lower layer absorber are not adhere | attached.
[0023]
The material for forming the sanitary napkin of the present embodiment will be described. As the material for forming the top sheet 2 and the back sheet 3, various materials conventionally used for absorbent articles such as sanitary napkins are not particularly limited. Can be used.
[0024]
As the material for forming the upper layer absorbent body 41 and the lower layer absorbent body 42, various materials conventionally used for absorbent bodies of absorbent articles can be used, but fiber aggregates such as fluff pulp, paper, and nonwoven fabric can be used. And the thing consisting of a water-absorbing polymer is preferable, and the upper layer absorbent body 41 is particularly preferably one obtained by three-dimensionally dispersing the water-absorbing polymer in the fiber assembly.
When an absorbent body in which a water-absorbing polymer is three-dimensionally dispersed is used as the upper layer absorbent body 41, the excreted liquid can be quickly absorbed and immobilized by the water absorbent polymer after being absorbed by the upper layer absorbent body 41. Become. In the case of the upper layer absorbent body 41 formed of only a fiber aggregate, the excreted liquid is once absorbed by the upper layer absorbent body 41. In the fiber aggregate in the upper layer absorbent body 41, a capillary phenomenon occurs between the fibers. Causes large liquid spreading, and the liquid spreading becomes large even when the amount of absorption is small.
In addition, that the water-absorbing polymer is dispersed three-dimensionally means that the water-absorbing polymer is dispersed not only in the plane direction (horizontal direction) but also in the thickness direction in the fiber assembly. If the water-absorbing polymer is dispersed two-dimensionally in the plane direction (horizontal direction), conversely, it is a major cause of gel blocking due to the water-absorbing polymer absorbing the liquid, and as a result, sufficient It becomes difficult to obtain as an absorber having an absorption amount.
Accordingly, it is particularly preferable that the material is uniformly dispersed in the plane direction and the thickness direction.
[0025]
Examples of the fibers constituting the fiber assembly include pulp fibers, cotton fibers, cellulosic fibers such as rayon and cupra, and synthetic fibers made of synthetic resins such as polyester and polyethylene. Those capable of absorbing and holding twice or more liquid and capable of gelling are preferred. Preferable examples of the water-absorbing polymer include polyacrylic acid and a salt thereof, and a polyacrylate graft polymer such as starch, crosslinked carboxylmethylated cellulose, a polymer or a copolymer of acrylic acid or an alkali metal acrylate. be able to. The fiber assembly may be a nonwoven fabric.
[0026]
Further, the upper layer absorbent body 41 was immersed for 30 minutes in saline, the liquid holding amount after dewatering 2000 rpm, 10 minutes at centrifuge 100 to 2000 g / m ^2, especially at 200~1100g / m ² Preferably there is.
When the upper layer absorber 41 has a liquid holding amount of 100 to 2000 / m ² , the excreted liquid can be absorbed and held by the upper layer absorber, and when the excreted liquid amount is large, it is transmitted to the lower layer absorber. However, it is possible to absorb and hold the liquid on both sides, and the upper layer absorber alone absorbs and holds the liquid, which inhibits the efficient transmission of the absorbed liquid to the lower layer absorber. This is preferable. In particular, since the upper layer absorber and the lower layer absorber are disposed in the excretory part, the above range is preferable in order to effectively utilize the liquid absorbing ability of the upper and lower absorbers.
Further, the amount of liquid retained in the lower layer absorber 42 needs to have an absorption capacity for efficiently absorbing and fixing the liquid transmitted from the upper layer absorber. From these viewpoints, the liquid holding amount is preferably 200 to 2000 g / m ² , particularly preferably 400 to 1500 g / m ² .
[0027]
The liquid holding amount of the upper layer absorber 41 and the lower layer absorber 42 is measured as follows.
The upper absorbent body 41 is carefully removed from the sanitary napkin 1 and cut into a width of 50 mm and a length of 100 mm to obtain a test piece. Moreover, in the case of the lower layer absorber 42, when a width or length is larger than the said test piece of an upper layer absorber, it cuts out to the said width or length, and is set as a test piece. The cut specimen is placed in a bag made of 250 mesh nylon mesh. At this time, the weight of the test piece and the tare of the nylon net are weighed in advance. The bag containing the test piece is immersed in physiological saline and left for 30 minutes. The test piece is taken out from the physiological saline together with the bag, dehydrated with a centrifuge at 2000 rpm for 10 minutes, and the weight after dehydration is measured. The liquid holding amount is obtained as a liquid holding amount per 1 m ² from the following formula.
Liquid retention amount = (weight after dehydration− (weight of bag + weight of test piece)) / area of test piece
The sanitary napkin 1 of the present embodiment can be used by being fixed at a predetermined position such as shorts in the same manner as a conventional sanitary napkin.
[0029]
Since the sanitary napkin 1 of the present embodiment is configured as described above, a large step does not occur at the peripheral edge of the middle-high part 6, and the peripheral part of the middle-high part 6 has a gently curved shape. Therefore, the wearer does not feel uncomfortable at the time of wearing or feels uncomfortable.
[0030]
In addition, since the sanitary napkin 1 of the present embodiment is configured as described above, the cross-sectional shape in the width direction of the wearer's crotch K is as shown in FIG. Easily deforms into an inverted U-shape along the arch shape, so that the cross-sectional shape is deformed into a W shape, thereby preventing the occurrence of leakage, deterioration of fit and wearing feeling, etc., and excellent leakage prevention A feeling of fitting and wearing can be obtained reliably.
[0031]
Next, the sanitary napkin of 2nd Embodiment of this invention is demonstrated.
About the sanitary napkin 1 'of 2nd Embodiment, a different point from the napkin 1 of 1st Embodiment is demonstrated. The points that are not particularly described are the same as those in the first embodiment, and the above-described description with respect to the first embodiment is appropriately applied.
[0032]
In the sanitary napkin 1 ′ of the second embodiment, as shown in FIG. 4, grooves 5 and 5 are formed only on both sides in the width direction of the portion 41 a corresponding to the lower layer absorber 42 on the surface side of the upper layer absorber 41. Has been. Moreover, although the full length of the upper layer absorber 41 is the same as 1st Embodiment, the length L1 of the lower layer absorber 42 is shorter than the thing of 1st Embodiment. In addition, the groove | channel 5 and the groove | channel 7 in napkin 1 'of 2nd Embodiment each have the circular-arc-shaped planar view shape curved concavely toward outward. 4 is the same as FIG. 2 except that the positions of the grooves 5 and 7 are slightly shifted in the width direction.
[0033]
Since the napkin 1 ′ of the second embodiment has such a configuration, the same operational effects as the napkin 1 of the first embodiment are exhibited.
[0034]
The absorbent article of the present invention is not limited to the first and second embodiments described above, and various changes can be made without departing from the spirit of the present invention.
For example, the lower layer absorbent body 42 may be biased either before or after the napkin 1 in the longitudinal direction, or may be arranged so as to cover the entire length of the upper layer absorbent body 41 in the longitudinal direction.
In addition to the upper layer absorber 41 and the lower layer absorber 42, the absorber 4 may have a third absorption layer on the back surface side of the lower layer absorber 42 and the like. The present invention can also be applied to incontinence pads, panty liners and the like in addition to sanitary napkins.
[0035]
【The invention's effect】
The absorbent article of the present invention has a smooth surface shape at the peripheral edge of the middle and high parts, can prevent the wearer from feeling uncomfortable or uncomfortable, and is difficult to deform into a W-shaped cross section, and has excellent leakage prevention , Fit and wearing feeling can be reliably obtained.
[Brief description of the drawings]
FIG. 1 is a plan view showing a sanitary napkin as an embodiment of the present invention.
FIG. 2 is an enlarged sectional view taken along line XX of FIG.
FIG. 3 is a schematic view showing a deformed state when the sanitary napkin shown in FIG. 1 is attached.
FIG. 4 is a plan view showing a sanitary napkin as another embodiment of the present invention.
[Explanation of symbols]
1,1 'sanitary napkin (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 41 Upper layer absorber 42 Lower layer absorber 41a Part 5 corresponding to the lower layer absorber on the surface side of the upper layer absorber

Claims (6)

In an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet and an absorbent body interposed between both sheets, and formed substantially vertically long,
The absorber includes an upper layer absorber and a lower layer absorber formed in a smaller size than the upper layer absorber and laminated on the back side of the upper layer absorber, and the lower layer on the surface side of the upper layer absorber Grooves are formed in portions located outward from both side edges of the absorber, and the horizontal distance between the side edges of the lower layer absorber and the grooves located at the outside is 2 to 10 mm,
The upper layer absorber has a bending moment of 0.5 to 60 mN · m at the portion located on the lower layer absorber , and the upper layer absorber has a portion located on the lower layer absorber protruding upward. Absorbent article. The absorptive article according to claim 1 whose width of said lower layer absorber is 20-70% to the width of said upper layer absorber .   The absorbent article according to claim 1 or 2, wherein in the width direction, a bending moment for bending toward the skin contact surface side is greater than a bending moment for bending toward the non-skin contact surface side.   The lower layer absorber has a thickness (T1) of 2 to 20 mm, and the upper layer absorber and the thickness (T2) of the absorbent article in the portion where the lower layer absorber is laminated, and the upper layer absorber are arranged. The absorptive article according to any one of claims 1 to 3 whose thickness difference (T2-T3) of the thickness (T3) of the absorptive article in the part in which this lower layer absorber is not arranged is 1-10 mm.   The absorbent article according to any one of claims 1 to 4, wherein the upper layer absorbent body and the lower layer absorbent body are not bonded to each other. The absorbent article according to prior Kimizo outside of each further one of claims 1 to 5 which is a groove in the upper layer absorbent body.

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