JP2006346021A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the liquid permeability from an upper-layer absorbent body to a lower-layer absorbent body, while retaining the absorbing speed in the upper-layer absorbent body and improving the mutual balance in an absorbent article having the absorbent body formed by superposing the upper-layer absorbent body on the lower-layer absorbent body. <P>SOLUTION: The upper-layer absorbent body 4A includes at least pulp fibers and synthetic fibers. Also, the ratio of the pulp fibers to the synthetic fibers is specified to be 80-20:20-80 in the weight conversion. The upper-layer absorbent body 4A is superposed on the lower-layer absorbent body 4B without an adhesive, and an embossment is formed from the upper face and/or the circumferential outer part of the upper-layer absorbent body 4A toward the lower-layer absorbent body 4B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to absorbent articles such as sanitary napkins, panty liners, and incontinence pads for absorbing menstrual blood and vaginal discharge, and more specifically, the absorbent body has a laminated structure of an upper layer absorbent and a lower layer absorbent. The present invention relates to an absorbent article.

  Conventionally, as an absorbent article such as a panty liner, sanitary napkin, incontinence pad, a liquid-impervious back sheet such as a polyethylene sheet or a polyethylene sheet-laminated nonwoven fabric, and a liquid-permeable surface sheet such as a nonwoven fabric or a liquid-permeable plastic sheet There is known an intervening absorber made of cotton-like pulp or the like.

  Many improvements have been made to this type of absorbent article, and various measures have been taken to prevent leakage of body fluids. As one of these body fluid leakage prevention means, a middle-high part thickened on the surface side is formed in the substantially central region of the absorber to improve the fit to the blood drainage part, and the shape of the middle-high part is maintained. Therefore, an absorbent article is known in which linear embossing is performed on the outer peripheral position of the middle-high portion (see Patent Documents 1 to 3 below).

In each absorbent article described above, when defibrated pulp obtained by crushing pulp is used as an absorber, the pulp piled up on the line may drop off, or the equipment may be adversely affected by transfer of pulp fibers, etc. It is surrounded by crepe paper immediately after stacking so as not to reach. In this case, in the case of the defibrated pulp absorber having the middle and high parts, as shown in FIG. 13A, the defibrated pulp layer 54 constituting the general part absorber and the defibrated pulp constituting the middle and high part absorber. A mode in which the layers 55 are collectively surrounded by the crepe paper 56, or, as shown in FIG. 13B, after the defibrated pulp layer 54 constituting the general absorber is surrounded by the crepe paper 56, the crepe paper 56 is also used. There is an aspect in which the defibrated pulp layer 55 constituting the middle and high part absorbent body surrounded by is laminated on it.
JP 10-328233 A Japanese Patent Laid-Open No. 11-358 JP-A-11-33054 JP-T 9-505218

  As described above, in the case of the absorber in which the middle-high part absorber (upper layer absorber) is laminated on the upper surface of the general part absorber (lower layer absorber), body fluid such as menstrual blood is discharged to the upper layer absorber and absorbed in the upper layer Penetration into the body, part of which is absorbed and retained by the upper layer absorber, and most of the remainder passes through the upper layer absorber to reach the lower layer absorber and is desirably absorbed and retained by the lower layer absorber. Most of the body fluid is absorbed and held in the upper absorbent body, which causes the upper absorbent body to become saturated or to be easily reverted by receiving pressure.

  On the other hand, the upper-layer absorber and the lower-layer absorber can be bonded to each other by a method of embossing the peripheral portion of the upper-layer absorber to prevent misalignment, as well as bonding the upper-layer absorber and the lower-layer absorber with an adhesive. Although it has been carried out (see Patent Document 4 and the like), there is a problem that the liquid permeability is inhibited by the adhesive and the amount of body fluid passing to the lower layer absorber is reduced.

Furthermore, according to the knowledge by the present inventors, the diffusion rate is relatively low in the crepe paper, such as crepe paper: 0.25 cm ³ / sec and pulp + polymer: 0.38 cm ³ / sec. As described above, when the upper absorbent body is surrounded by the crepe paper and the lower absorbent body is surrounded by the crepe paper, the multilayer crepe paper is interposed between the upper absorbent body and the lower absorbent body. As a result, the body fluid remains absorbed and retained on the multilayer crepe paper, which causes a decrease in the body fluid transfer to the lower layer absorber.

  Therefore, the main problem of the present invention is to improve the liquid permeability from the upper layer absorber to the lower layer absorber in the absorbent article including the absorber in which the upper layer absorber and the lower layer absorber are laminated, and at the same time, An object of the present invention is to provide an absorbent article that maintains an absorption rate in an absorbent body and is excellent in mutual balance.

As the present invention according to claim 1 for solving the above problem, an absorber is interposed between a liquid-permeable top sheet and a back sheet, and the absorber is a laminate of an upper layer absorber and a lower layer absorber. In an absorbent article having a structure,
The upper layer absorbent includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers: synthetic fibers is 80 to 20:20 to 80 in terms of weight,
The upper layer absorber and the lower layer absorber are laminated without using an adhesive, and are embossed from the upper surface and / or outer periphery of the upper layer absorber toward the lower layer absorber. A sex article is provided.

  In the present invention according to the first aspect, the upper-layer absorber includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers: synthetic fibers is set to 80 to 20:20 to 80 in terms of weight. is there. The larger the synthetic fiber mixing ratio, the better the body fluid permeability from the upper layer absorber to the lower layer absorber, but the synthetic fiber has no water absorption or water absorption even if it is hydrophilic. Since it is low, the absorption speed of body fluid will fall. However, when the mixing ratio of the synthetic fibers is 20 to 80% by weight, the liquid permeability of the upper absorbent body can be sufficiently secured, and the absorption speed can be maintained at or higher than the required performance.

  Further, the upper layer absorber and the lower layer absorber are laminated without using an adhesive, and the upper layer absorber and / or the outer periphery of the upper layer absorber are embossed from the outer periphery toward the lower layer absorber, thereby causing mutual positional deviation. Therefore, the adhesive does not inhibit the liquid permeability from the upper layer absorber to the lower layer absorber, and the liquid permeability of the upper layer absorber can be sufficiently ensured.

  As the present invention according to claim 2, there is provided the absorbent article according to claim 1, wherein the body fluid permeability in the upper layer absorbent is 85% or more.

  Specifically, the liquid permeability in the upper layer absorber is desirably 85% or more. As defined in the invention according to claim 1, the liquid permeability is such that the mixing ratio of the synthetic fibers of the upper layer absorbent is 20% by weight or more based on the total amount of pulp fibers and synthetic pulp, and the upper layer absorbent and the lower layer The absorber can be achieved by laminating without using an adhesive.

  As the present invention according to claim 3, the absorption rate of the seventh time when 3.5 cc of artificial menstrual blood is absorbed seven times every 8.5 minutes is 25 seconds or less on the liquid-permeable top sheet surface. An absorbent article according to any one of claims 1 and 2 is provided.

  It is desirable that the absorption rate of the seventh time is 25 seconds or less when 3.5 cc of artificial menstrual blood is absorbed seven times every 8.5 minutes on the surface of the liquid-permeable top sheet. As defined in the invention of claim 1, this absorption rate can be achieved by setting the mixing ratio of the synthetic fibers of the upper-layer absorber to 80% by weight or less based on the total amount of pulp fibers and synthetic pulp. it can.

  According to a fourth aspect of the present invention, the upper layer absorber and the lower layer absorber are surrounded by crepe paper, and an opening is formed in the crepe paper at least on the lower surface of the upper layer absorber and / or the upper surface of the lower layer absorber. Item 4. An absorbent article according to any one of Items 1 to 3 is provided.

  The invention according to the fourth aspect defines the surrounding form of the absorbent body by crepe paper. The smaller the crepe paper existing at the interface between the upper layer absorber and the lower layer absorber, the better the liquid permeability. However, it is also necessary to surround the absorbent body with crepe paper so that the piled fiber on the line does not fall off or adversely affect the equipment due to the transfer of pulp fibers. By forming openings in the paper, the number of layers of the crepe paper can be reduced, or by omitting the crepe paper, the liquid permeability impeding factor can be reduced or eliminated.

  The present invention according to claim 5, wherein the upper layer absorber and the lower layer absorber are surrounded by crepe paper in a state where the upper layer absorber and the lower layer absorber are laminated. An absorbent article is provided.

  The invention described in claim 5 defines the surrounding form of the absorbent body by crepe paper. The smaller the crepe paper existing at the interface between the upper layer absorber and the lower layer absorber, the better the liquid permeability. However, it is also necessary to surround the absorbent body with crepe paper so that the piled fiber on the line does not fall off or adversely affect the equipment due to transfer of pulp fibers, etc. In the state where the lower layer absorber is laminated, the upper layer absorber and the lower layer absorber are surrounded by crepe paper, and the upper layer absorber and the lower layer absorber are brought into direct contact with each other, thereby eliminating the liquid permeability inhibiting factor. be able to.

  As described above in detail, according to the present invention, in an absorbent article including an absorbent body in which an upper-layer absorbent body and a lower-layer absorbent body are laminated, simultaneously with improving the body fluid permeability from the upper-layer absorbent body to the lower-layer absorbent body. In addition, the absorption rate in the upper-layer absorbent body is maintained and the balance between them is excellent.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Basic structure of sanitary napkin 1]
1 is a development view of a sanitary napkin 1 according to a first embodiment of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. 3 is a view taken along the line III-III in FIG. is there.

The sanitary napkin 1 includes a liquid-impervious back sheet 2 made of a polyethylene sheet, a liquid-permeable top sheet 3 that allows permeation of menstrual blood, cages, and the like, and an intervening sheet between the sheets 2 and 3. Absorbent bodies 4 and 6 made of cotton-like pulp or synthetic pulp, etc., crepe paper 5 surrounding the absorbent body 4 for maintaining the shape of the absorbent body 4 and improving diffusibility, and the abbreviation of the absorbent body 4 It is mainly composed of a pair of left and right three-dimensional gathers BS, BS provided to protrude from the surface side in a predetermined section in the front-rear direction so that the side edge portion is an upright base end and includes at least a body fluid discharge portion, and In the periphery of the absorbent body 4, the outer edge portions of the liquid-impervious backsheet 2 and the liquid-permeable topsheet 3 are formed at the upper and lower edge portions thereof by an adhesive such as hot melt or an adhesive means such as heat seal. In addition, the liquid-impervious backsheet 2 extending laterally from the absorbent body 4 at both side edges and the side nonwoven fabric 7 forming the three-dimensional gather BS are bonded by hot melt or the like. Wing-like flaps W and W that are joined by adhesive means such as an agent and heat seal and project laterally by the laminated sheet portion of the liquid-impermeable back sheet 2 and the side nonwoven fabric 7 are formed. the second wing-shaped flaps W _B to the portion located on the buttocks _side, W _B are formed.

Hereinafter, the structure of the sanitary napkin 1 will be described in detail.
As the liquid-impervious backsheet 2, a sheet material having at least water shielding properties such as polyethylene is used. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used. One or a plurality of adhesive layers (not shown) are formed on the non-use side (outer surface) of the liquid-impermeable back sheet 2 so as to fix the sanitary napkin 1 to the underwear when worn on the body. It has become. As the liquid-impermeable back sheet 2, a polylaminated nonwoven fabric in which a plastic film and a nonwoven fabric are laminated may be used.

  Next, the liquid-permeable top sheet 3 is preferably a porous or non-porous nonwoven fabric or a porous plastic sheet. As the material fibers constituting the nonwoven fabric, in addition to olefins such as polyethylene or polypropylene, polyesters, polyamides, and other synthetic fibers, regenerated fibers such as rayon and cupra, and natural fibers such as cotton can be used. A nonwoven fabric obtained by an appropriate processing method such as a method, a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of being bulky and soft. When a large number of through holes are formed in the liquid permeable top sheet 3, menstrual blood, venom, etc. (hereinafter collectively referred to as body fluid) are quickly absorbed, and the dry touch property is excellent. It will be a thing.

  The absorber 4 has a structure in which an upper layer absorber 4A and a lower layer absorber 4B are laminated. The lower layer absorber 4B has a planar shape that defines the outer edge of the absorber arrangement region, and the upper layer absorber 4A is formed in a region that is elongated in the napkin longitudinal direction at the center portion in the width direction, on the use surface side. Arranged to form the mid-high section 6 of the high absorber. The thickness of the middle-high portion 6 is preferably 3 to 20 mm, more preferably 5 to 15 mm, because if the thickness is too large, the rigidity of the absorber 4 increases and the adhesion to the body decreases. Embosses 8 that are closed in the circumferential direction are provided along the peripheral edge of the upper layer absorbent body 4 </ b> A, and embosses 9, 10, and 11 are formed respectively. The embossing 8 is an embossing provided to prevent the positional deviation of the upper layer absorbent body 4A and to precisely define the middle and high portions 6. The embosses 8 to 11 will be described in more detail later.

  The upper absorbent body 4A includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers: synthetic fibers is 80 to 20:20 to 80, preferably 40 to 60:60 to 40 in terms of weight. Shall be. According to the Example mentioned later, the liquid permeation | transmission from 4 A of upper layer absorbers to 4 A of lower layer absorbers by making the mixing ratio of the synthetic fiber of 4 A of upper layer absorbers into 20 weight% or more with respect to the whole quantity of a pulp fiber and synthetic pulp. It is possible to make the rate 85% or more, and by setting the mixing ratio of the synthetic fibers of the upper layer absorbent body 4A to 80% by weight or less based on the total amount of the pulp fibers and the synthetic pulp, The absorption rate at the seventh time when 3.5 cc of artificial menstrual blood is absorbed seven times every 8.5 minutes can be 25 seconds or less. Moreover, when the mixing ratio of the synthetic fibers of the upper layer absorbent body 4A is 40 to 60% by weight with respect to the total amount of pulp fibers and synthetic pulp, the liquid permeability from the upper layer absorbent body 4A to the lower layer absorbent body 4B is 88. % Or more and the absorption rate can be 24 seconds or less.

  The upper layer absorbent body 4A is expelled to the upper surface of the liquid-permeable top sheet 3 and the first function of permeating the absorbed body fluid into the lower layer absorbent body 4B side without suspending the body fluid though it expedites the body fluid functionally. Where it is necessary to satisfy both the second function of quickly absorbing bodily fluids in a well-balanced manner, if synthetic fibers are mixed too much in order to improve the permeability of the first function, does the synthetic fiber have water absorption? Even if it has been subjected to a hydrophilic treatment, the water absorption rate is low, so that the absorption rate of the body fluid is lowered. In the case of a person with a large amount of menstrual blood, in order to prevent leakage after wearing the napkin for 1 hour, it is desirable that the liquid permeability of the upper absorbent body 4A is 85% or more and the absorption rate is 25 seconds or less. By setting the mixing ratio of the fiber and the pulp fiber to the above-mentioned numerical value, the first function and the second function can be made compatible with each other in a balanced manner. Further, by mixing the synthetic fiber with the upper layer absorbent body 4A, the bulk can be maintained and the cushioning property can be maintained without being deflated even when the body fluid is absorbed.

  As the synthetic fiber, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used. It may be a mixture. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be used. In the case of a hydrophobic fiber, it is desirable to use a synthetic fiber that has been surface-treated with a hydrophilizing agent so as to have an affinity for body fluids.

  The upper layer absorbent body 4A can contain a highly water absorbent resin. Examples of the superabsorbent resin include cross-linked polyacrylate, self-crosslinked polyacrylate, saponified acrylate-vinyl acetate copolymer cross-linked, isobutylene / maleic anhydride copolymer cross-linked, Examples include cross-linked polysulfonates, and partially cross-linked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. In the production process of the highly water-absorbent resin having the water absorption performance, the water absorption force and the water absorption speed can be adjusted by adjusting the crosslinking density and the crosslinking density gradient. The blending amount is required to promote penetration of the upper absorbent body 4A into the lower absorbent body 4B, and so-called gel blocking phenomenon occurs when the blending amount is increased. Therefore, the blending amount is 1 in terms of weight with respect to the total weight of pulp fibers and synthetic fibers. It is desirable to blend at a ratio of -10%. In addition, when the high water-absorbing resin content exceeds 50%, the entanglement between the pulp fibers is lost, the sheet strength is lowered, and tearing, cracking, and the like are likely to occur.

  Examples of the pulp fiber include cellulose fibers such as chemical pulp and molten pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. It is preferably used in terms of price.

  On the other hand, the lower layer absorbent body 4B does not need to contain a synthetic fiber, and can be a pulp fiber alone or a mixture of a pulp fiber and a superabsorbent resin. In the lower layer absorbent body 4B, permeability is not considered important, and it is desirable that the body fluid that has permeated from the upper layer absorbent body 4A is retained inside and retained so as not to bleed out. . The content of the superabsorbent resin is desirably blended at a rate of 1 to 20% by weight with respect to the total weight of the fibers constituting the lower layer absorbent body 4B in order to absorb body fluid and retain water.

  The upper layer absorber 4A and the lower layer absorber 4B are surrounded by the crepe paper 5, respectively. When the absorbers 4A and 4B are surrounded by the crepe paper 5, and the upper layer absorber 4A surrounded by the crepe paper 5, Even when laminating the lower layer absorber 4B, as shown in the schematic diagram of FIG. 4A without using an adhesive for bonding them, the positional deviation of the upper layer absorber 4A is 4A. It is good to carry out by the embossing 8 provided in the periphery.

  Further, when the upper layer absorber 4A surrounded by the crepe paper 5 and the lower layer absorber 4B surrounded by the crepe paper 5 are stacked, the boundary surface between the upper layer absorber 4A and the lower layer absorber 4B is doubled. The crepe paper 5 is laminated, and this crepe paper 5 inhibits liquid permeability. However, since it is necessary to surround the absorbent bodies 4A and 4B with the crepe paper 5 so that the piled fiber on the line does not fall off or adversely affect the equipment due to transfer of pulp fibers, etc., It is desirable to form an opening in the crepe paper 5 on the lower surface of the upper absorber 4A and / or the upper surface of the lower absorber 4B. 4B is an example in which an opening is formed in the crepe paper 5 on the upper surface of the lower layer absorbent body 4B, and FIG. 4C is an example in which an opening is formed in the crepe paper 5 on the lower surface of the upper layer absorbent body 4A. FIG. 4D shows an example in which openings are formed in the crepe paper 5 on the upper surface of the lower layer absorber 4B and the lower surface of the upper layer absorber 4A. Further, the embossing 8 for preventing the positional deviation of the upper layer absorber 4A is not limited to the outer periphery of the upper layer absorber 4A, and the emboss 8 is applied from the upper surface of the upper layer absorber 4A toward the lower layer absorber 4B. May be. In this case, it is made to perform under high pressure so that the hollow by the emboss 8 may bite into the lower layer absorber 4B.

  Further, in order to eliminate the inhibition of liquid permeability caused by the crepe paper 5, as shown in FIG. 5 (A), in the state where the upper layer absorbent body 4A and the lower layer absorbent body 4B are laminated, these upper layer absorbent bodies. You may make it surround 4A and lower layer absorber 4B with the crepe paper 5. FIG. FIG. 5B shows an example in which the emboss 8 is further provided from the outer periphery and the center of the upper absorbent body 4A.

On the other hand, the width dimension of the liquid-permeable top sheet 3 is slightly longer than the width of the absorbent body 4 and covers the absorbent body 4 as shown in the cross-sectional views of FIGS. The purpose of the three-dimensional gathered BS is to prevent the permeation of menstrual blood, or the like from the side non-woven fabric 7 different from the liquid-permeable top sheet 3, specifically to increase the feeling of touch. Depending on the case, it is configured using a non-woven fabric material subjected to appropriate water repellent treatment or hydrophilic treatment. The side nonwoven fabric 7 can be made of natural fiber, synthetic fiber, regenerated fiber, or the like and formed by an appropriate processing method. Preferably, the side nonwoven fabric 7 eliminates the feeling of stickiness and prevents stuffiness. For this reason, it is preferable to use a non-woven fabric with reduced basis weight and air permeability. Specifically, it is desirable to use a nonwoven fabric prepared with a basis weight of 18 to 23 g / m ² , and silicon-based, paraffin-based, alkylchromic chloride-based water repellents, etc. to reliably prevent the passage of body fluids. A water repellent nonwoven fabric coated with is preferably used.

As shown in FIGS. 2 and 3, the side nonwoven fabric 7 has an outer portion from the intermediate portion in the width direction from the inner position of the absorbent body 4 to slightly beyond the absorbent side edge to the outer edge of the liquid-impermeable backsheet 2. A pair of left and right wings are bonded to the absorbent body side portion substantially corresponding to the body fluid discharge portion by the laminated sheet portion of the side nonwoven fabric 7 and the liquid-impervious back sheet 2. flaps W, to form a W, a second wing-shaped flaps W _B now to the buttocks side _position, to form a W _B. These wing-shaped flaps W, W and second wing-shaped flaps W _B, W outer surface respectively the adhesive layer on the side 12 of the _B ..., 13 ... comprises a, as shown in FIG. 11, when worn against shorts 30, wherein The wing-shaped flaps W, W are folded back to the opposite side at the position of the folding line RL, and are wound around the crotch portion of the shorts and fastened.

  On the other hand, while the inner side part of the said side nonwoven fabric 7 is folded back substantially double, the thread-like elastic elastic member by which the appropriate position of the both ends or the longitudinal direction was fixed to the height direction intermediate part inside this double sheet | seat 19, and a plurality of, in the illustrated example, two thread-like elastic stretch members 20, 20 are fixed at both ends or at appropriate positions in the longitudinal direction at the upper portion of the thread-like elastic stretch member 19. It is arranged. As shown in FIG. 3, the double sheet portion is folded and laminated in a Z-shaped cross section at the front and rear end portions, and is bonded to the absorbent body 4 side, whereby the thread elastic elastic member 19 is disposed. As the bending points, three-dimensional gathers BS and BS standing on the surface side are formed while forming pockets P and P having openings inward in a cross-sectional shape.

[Embossed structure]
In the sanitary napkin 1, as shown in detail in FIG. 6, the napkin 1 has a medium-high portion 6 of a high absorbent body on the use surface side at the center in the width direction and surrounds the medium-high portion 6. A long emboss 8 is formed in the longitudinal direction. The emboss 8 is composed of a front end emboss 8a, a reduced shape emboss 8b, a first bulge shape emboss 8c, an intermediate arc emboss 8d, a second bulge shape emboss 8e, and a rear side emboss 8f in this order from the front side. Has been. Each of these embosses is formed continuously without being divided, and is closed in the circumferential direction as a whole.

  The front end embossing 8a is an embossing formed in a substantially semicircular arc shape, and embossing a pair of left and right embossing formed on both sides of the middle and high part 6 along the substantially longitudinal direction with a curved line at the front end of the napkin. It is.

  The reduced shape embossing 8b is a pair of left and right embossing lines formed so as to extend in the longitudinal direction of the napkin 1 on both sides of the middle-high part 6 continuously to the front end embossing 8a. In addition, as shown in the figure, the embossed lines on both sides are each formed by a curve having a center of curvature on the outer side of the napkin 1 so as to form a reduced region of the embossing separation width.

  The first bulging shape embossing 8c is a pair of left and right embossing lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the reduced shape embossing 8b. The emboss lines on both sides are formed by curves having a center of curvature on the center side of the napkin 1 so as to be located on the rear side of the thigh and to form an enlarged region of the emboss separation width.

  The intermediate arc-shaped emboss 8d is a pair of left and right emboss lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the first bulge-shaped emboss 8c. 7, the embossed lines on both sides are formed in a very short section by a curve having the center of curvature on the outer side of the napkin 1 with the inflection point where the position of the center of curvature is reversed as a boundary. ing.

  The second bulge-shaped emboss 8e is a pair of left and right emboss lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the intermediate arc-shaped emboss 8d. 7, emboss lines on both sides are formed by curves having a center of curvature on the center side of the napkin 1 with an inflection point where the position of the center of curvature is reversed as a boundary. The second bulge-shaped emboss 8e is formed with a relatively short section width as compared with the first bulge-shaped emboss 8c.

  The rear-side embossing 8f is a pair of left and right embossing lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the second bulge-shaped embossing 8e. In the example shown, it is extended to the rear side so as to gradually narrow the separation width of the embosses, and the embosses on both sides are joined by arcuate curved embosses on the rear side. At the middle position near the rear side of the rear side emboss 8f, a third bulge-shaped emboss is formed by a curve in which each emboss has a center of curvature on the center side of the napkin 1 so as to form an embossed separation width enlarged region. 8 g is formed.

  On the outside of the rear-side emboss 8f, second rear-side embosses 10 and 10 extending in the longitudinal direction of the napkin 1 are formed so as to be spaced from the rear-side emboss 8f. In the illustrated example, each of the second rear-side embosses 10 is an arcuate curve having a center of curvature on the outside of the napkin 1.

  In addition, a substantially umbrella-shaped front end independent emboss 9 is formed on the front side of the front end emboss 8a, and a substantially inverted umbrella shape is formed on the rear side of the rear side emboss 8f. A rear end independent emboss 11 is formed.

  According to the various embosses 8 to 11 formed as described above, the following effects can be obtained.

First, in the formation region of the first bulge-shaped emboss 8c, the intermediate arc-shaped emboss 8d, and the second bulge-shaped emboss 8e, the bulge-shaped emboss 8c, The formation region 8e is a region that is difficult to bend with a line in the napkin width direction as a flexible axis (folded line) by an embossing line that bulges outward, but an intermediate portion sandwiched between these bulging shape embossments 8c and 8e. for arcuate emboss 8d is an area where embossed curve is inverted, each bulged shape emboss 8c, since the restraining force of the distortion of 8e is opened, the flexible line X ₁ -X ₁ of relatively napkin width direction It is easy to bend as an axis.

  On the other hand, if the napkin 1 is attached to the shorts 30 as shown in FIG. 11, the regions of the reduced shape emboss 8b and the first bulge shape emboss 8c are compressed inward from the thigh. At the same time, the compressing force compresses the absorbent body 4 in the width direction, and at the same time, the force is transmitted by the embossing 8 formed along the longitudinal direction of the napkin. The acting forces F1 and F2 directed toward the side act. Further, when the crotch portion of the shorts 30 is pulled up to the body side, the napkin 1 receives a pressing force that presses against the crotch portion along the longitudinal center line YY.

By receiving such a force above, in the Z ₁ region, the first raised portion R ₁ is formed in the first protruding shape emboss 8c portion corresponding to Haichiguchi, the raised portions R ₁ Can absorb menstrual blood and the like by adhering to the vicinity of the blood outlet. Further, the second bulging shape emboss 8e site corresponding to perineal toward anus in the rear side from the vaginal opening is a via an intermediate arcuate emboss 8d which X ₁ -X ₁ flexible shaft is formed 2 ridges R ₂ are formed, and when this ridge R ₂ is closely attached to the perineum, it absorbs menstrual blood and the like that could not be absorbed in the vicinity of the blood drainage port, and leaks the body fluid to the back side. It can be surely prevented.

That is, as shown in FIG. 7 (B), with an intermediate arcuate emboss 8d region distortion of the raised direction is opened, for the X ₁ -X ₁ flexible shaft, a first located before and after bulging shape emboss 8c region, and as the second bulging shape emboss 8e region continuous two peaks, now raised portion R _1, R ₂ is formed, the ridge R ₁ is Haiti in close contact with the vicinity of the mouth, the raised portions R ₂ will be able to reliably prevent run down leakage such as menstrual blood by close contact with the vicinity of the perineum. Incidentally, the raised portions R ₂ is in proportion to the formation scale of bulging shape emboss 8e, is formed smaller than the ridges R _1.

On the other hand, in the rear-side embossed 8f region, a second rear-side embossed 10 is formed in addition to the rear-side embossed 8f along the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6, respectively. Since the embossment of the strips respectively forms a flexible shaft, the flexibility in the direction along X ₂ -X ₂ is improved, and the fit to the valley portion of the hip is increased.

Further, a third swelled shape emboss 8g formed at the rear side near the position of the rear side emboss 8f is a transverse line _{X 3 -X 3, X 4 -X} 4 in each position corresponding to the inflection point position with which it is easy bent, since the distortion in the vertical direction line Y-Y direction of the napkin at each inflection point position is divided, made to fit in the valleys of the hip as region Z ₂ swells.

On the other hand, the substantially umbrella-shaped front end independent emboss 9 formed at the foremost end of the napkin 1 makes it easy to bend the front end portion of the napkin 1 by using this as a flexible shaft, and the substantially reverse shape formed on the rear side. rear independent emboss 11 of the umbrella shape, which is the second wing-shaped flaps W _B of the left and right become a flexible _shaft, to facilitate bending of W _B.

  By the way, in the napkin 1, the position of the blood outlet is generally determined as a corresponding position of the wing flaps W and W positions. For example, as shown in FIG. Various embosses 8 to 11 may be formed so as to be relatively shifted downward so as to correspond to the wing flaps W and W.

[Other examples]
(1) wherein a first protruding shape emboss 8c region, for facilitating bending of the napkin 1 at the flexible axis X ₁ -X ₁ position formed between the second protruding shape emboss 8e area, the napkin You may make it provide the auxiliary | assistant embossing along the substantially 1 width direction. FIG. 9A shows an example in which an arc-shaped emboss 14 oriented in the width direction is formed at the center in the width direction as the auxiliary emboss, and FIG. 9B shows an arc-shaped emboss in the width direction so as to connect the embosses on both sides. 15 is an example.
(2) In the above embodiment, the second rear embosses 10 and 10 are formed independently. However, as shown in FIG. 9C, the second rear embosses 10 and 10 and the rear end are formed. The independent embossing 11 may be continuous to form a substantially horizontal U-shaped continuous embossing 16.
(3) Further, as shown in FIG. 10, the region Y ₁ including the blood drainage site, the region Y ₂ including the perineum region-corresponding region, and the middle-high portion 6 of the region Y ₃ including the third bulge-shaped emboss 8g. It is desirable to improve the absorbability of menstrual blood and the like by forming a large number of small dent-like dodd embosses 18.18 on the surface. In the example of the figure, arc-shaped embosses 14 and 17 oriented in the width direction at the center in the width direction with respect to the adjacent positions of the flexible axes X _{1 to} X ₁ and the third bulge-shaped emboss 8g portions. Is forming.
(4) In the above embodiment, the emboss 8 has a pair of left and right emboss lines joined at the front end and the rear end of the napkin to form a closed shape as a whole. Or you may form in the aspect which is not couple | bonded at a rear-end part.

  Absorber samples in which the synthetic fiber mixing ratio of the upper-layer absorber 4A was variously changed were prepared, and an absorption rate test and a liquid permeability test were performed. The upper layer absorbent body 4A was made of PE / PET core-sheath type composite fiber subjected to a hydrophilic treatment, and the lower layer absorbent body 4B was made of an absorbent layer made of pulp fiber and superabsorbent resin without containing synthetic fibers.

図１２に示されるように、経血量が特に多い人が１時間ナプキンを装着した後に確実に漏れを防止するには、液透過率は８５％以上、吸収速度は２５秒以下とするのが望ましいため、合成繊維の混合率は２０〜８０％、好ましくは４０〜６０％とするのが良いことが判明した。 The absorption rate test assumes that a person with a particularly large amount of menstrual blood wears a napkin for 1 hour, and absorbs 3.5 cc of artificial menstrual blood 7 times every 8.5 minutes on the liquid-permeable topsheet surface. The seventh absorption rate (time until all 3.5 cc artificial menstrual blood was absorbed) was defined as the absorption rate. In the liquid permeability test, the weights of the upper layer absorber and the lower layer absorber were measured, and 3.5 cc of artificial menstrual blood was dropped on the upper layer absorber, and then left for 5 minutes, and then the upper layer absorber and the lower layer absorber. Was measured again and calculated from the amount of artificial menstrual blood that had penetrated into the lower layer absorber. The test results are shown in Table 1 below and shown in FIG.

As shown in FIG. 12, in order to reliably prevent leakage after a person with particularly high menstrual blood volume wears a napkin for 1 hour, the liquid permeability should be 85% or more and the absorption rate should be 25 seconds or less. Since it is desirable, it has been found that the mixing ratio of the synthetic fiber is 20 to 80%, preferably 40 to 60%.

It is an expanded view of the sanitary napkin 1 of this invention. It is the cross-sectional view (II-II line arrow view of FIG. 1). It is the cross-sectional view (III-III arrow directional view of FIG. 1). It is sectional drawing which shows the laminated structure (the 1) of 4 A of upper layer absorbers, and the lower layer absorber 4B. It is sectional drawing which shows the laminated structure (the 2) of upper layer absorber 4A and lower layer absorber 4B. It is explanatory drawing of the embossing 8-11. (A) is an enlarged view of the main part, and (B) is a view taken along the line BB. It is an expanded view of the sanitary napkin 1 which shifted the position of the embosses 8-11 downward. (A)-(C) is a figure showing a modification of embossing, respectively. It is an expanded view which shows the formation aspect of another emboss. It is a perspective view which shows the mounting state of a napkin. It is a graph which shows the test result in an Example. It is sectional drawing which shows the conventional absorber laminated structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sanitary napkin, 2 ... Impermeable back sheet, 3 ... Liquid permeable top sheet, 4 ... Absorber, 4A ... Upper layer absorber, 4B ... Lower layer absorber, 5 ... Crepe paper, 6 ... Middle high part, 7 ... Side nonwoven fabric, 8 ... Emboss, 8a ... Front end emboss, 8b ... Reduced shape emboss, 8c ... First bulge shape emboss, 8d ... Intermediate arc shape emboss, 8e ... Second bulge shape emboss, 8f ... Rear portion side embossing, 8 g ... third bulging shape embossing, 9 ... front end independent emboss, 10 ... second rear side emboss, 11 ... rear end independent emboss, BS ... standing gathers, W ... wing-shaped flaps, W B _... buttocks Side wing flap

Claims (5)

In the absorbent article in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and the absorbent body has a laminated structure of an upper layer absorbent body and a lower layer absorbent body,
The upper layer absorbent includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers: synthetic fibers is 80 to 20:20 to 80 in terms of weight,
The upper layer absorber and the lower layer absorber are laminated without using an adhesive, and are embossed from the upper surface and / or outer periphery of the upper layer absorber toward the lower layer absorber. Sex goods.   The absorbent article according to claim 1, wherein the body fluid permeability in the upper layer absorbent is 85% or more.   The absorption speed at the seventh time when 3.5 cc of artificial menstrual blood is absorbed seven times every 8.5 minutes on the surface of the liquid-permeable top sheet is 25 seconds or less. Absorbent articles.   The said upper layer absorber and lower layer absorber are enclosed by the crepe paper, and the opening is formed in the crepe paper at least in the lower surface of the upper layer absorber and / or the upper surface of the lower layer absorber. Absorbent article. The absorbent article according to any one of claims 1 to 3, wherein the upper layer absorber and the lower layer absorber are surrounded by crepe paper in a state where the upper layer absorber and the lower layer absorber are laminated.

Images