KR20050084838A - Absorbent article with liquid arresting layer - Google Patents

Abstract

An absorbent article with a liquid arresting layer (6) interposed between a surface sheet (3) and a liquid absorbing layer (4). The liquid arresting layer (6) is in the form of a water-absorbable sheet (8) three-dimensionally deformed to form longitudinal ribs (6a) raised toward the surface sheet (3) and extending longitudinally of the article in parallel to each other, and transverse ribs (6b) raised toward the surface sheet (3) and extending transversely of the article. The transverse ribs (6b) are disposed at longitudinally spaced intervals and serve to fasten adjacent longitudinal ribs (6a), with a plurality of recesses (6c) surrounded by the longitudinal ribs (6a) and transverse ribs (6b). At least the longitudinal ribs (6a) contact the upper member, and the bottoms (6d) of the recesses (6c) contact the liquid absorbing layer (4).

Description

Absorbent article having a liquid acquisition layer {ABSORBENT ARTICLE WITH LIQUID ARRESTING LAYER}

Mark of related application

This application is filed by claiming priority based on Japanese Patent Application No. 2002-354186, filed December 5,2002. The disclosure of the Japanese patent application is incorporated as part of the disclosure of the present specification.

Technical Field

TECHNICAL FIELD The present invention relates to an absorbent article suitable for absorption of menstrual blood and the like excreted from the female genitalia, and more particularly, to an absorbent article provided with a liquid acquisition layer for absorbing and imparting a liquid to the liquid absorbing layer between the surface sheet and the liquid absorbing layer. .

The general structure of an absorbent article that absorbs acupuncture points excreted from the female genitals includes a liquid permeable surface sheet located on the skin side surface, a liquid impermeable back sheet located on the wearing side surface, and between the surface sheet and the back sheet. Having a liquid absorbing layer interposed therebetween, it is usually worn on the inner surface of the crotch fabric of the underwear while the back sheet is adhered through the pressure-sensitive adhesive layer.

In this type of absorbent article, when a large amount of acupuncture points are given to the surface sheet at one time, the acupuncture points are left on the surface sheet for a long time, and the crotch is moistened to give a feeling of discomfort to the wearer. Therefore, when a large amount of liquid is given at one time, there have been devised to diffuse the liquid under the surface sheet or to hold it under the surface sheet.

Japanese Laid-Open Patent Publication No. 6-38998 (Patent Document 1) discloses a sanitary napkin provided with a liquid carrier between a surface sheet and a liquid absorbing layer.

The said liquid carrier has provided many concave screen patterns in the nonwoven fabric. The screen pattern is an embossed pattern in which a nonwoven fabric having a predetermined thickness is compressed from one side to form a high fiber density portion, and an embossed pattern in which the nonwoven fabric is compressed from both sides to form a thin film element. It is arranged toward the longitudinal direction (length direction) of the napkin. The liquid carrier is intended to restrict the movement of the menstrual blood penetrating the surface sheet by the thin film element to bypass the high fiber density portion, thereby spreading the menstrual blood in the longitudinal direction, thereby preventing liquid residue on the surface sheet. will be.

Next, Japanese Patent Application Laid-Open No. 2000-140015 (Patent Document 2) discloses a disposable diaper in which a liquid permeable sheet is interposed between a surface sheet and a liquid absorbing layer.

The liquid-permeable sheet has a plurality of recesses partitioned by convex portions in which a nonwoven fabric or paper is three-dimensionally deformed and extended in a mesh shape. This disposable diaper is intended to prevent the liquid from flowing along the surface of the diaper by holding the liquid once in the recess of the liquid permeable sheet when a large amount of liquid is given at one time.

Although the liquid carrier of the said patent document 1 may be able to diffuse the liquid which permeate | transmitted the surface sheet in the longitudinal direction, since the liquid holding capacity and liquid permeability of the liquid carrier itself are low, a large amount of acupuncture points are applied to the liquid carrier. Given that it is easy to stay saturated. In other words, the liquid carrier is formed by forming an embossed pattern on a melt blown nonwoven fabric or the like, but the melt blown nonwoven fabric remains relatively flat even after the embossing treatment, so that a large amount of liquid given locally cannot be maintained. Moreover, since the concave portion forming the embossed pattern on the nonwoven fabric has a very small space volume, it is hard to hold liquid in the concave portion. Rather, the melt blown nonwoven fabric has a high density of the blow blown nonwoven fabric itself, and blocks the permeation of the liquid through the thin film element, so that the liquid permeability is low.

Subsequently, the liquid permeable sheet described in Patent Literature 2 is intended to prevent urine from being stored in a triangular recess and spreading in a planar manner. However, since the diffusion of the liquid is suppressed by the mesh-shaped convex portions, the concave portions immediately become saturated due to the urine. Therefore, when this liquid permeable sheet is applied to a sanitary napkin, menstrual blood with a viscosity higher than urine tends to stay in this recess. Further, in Patent Literature 2, a preferred example of the liquid permeable sheet is formed of paper. However, when the liquid permeable sheet formed of such paper is used for a sanitary napkin, the recess is immediately damaged by the pressure given from the crotch of the wearer. The liquid-permeable sheet tends to be torn when broken, and when a force for shifting the position on the sanitary napkin is applied.

This invention is made | formed in view of the said conventional subject. Accordingly, it is an object of the present invention to provide an absorbent article which can maintain this temporarily when a large amount of liquid is given, can be smoothly transferred to the liquid absorbing layer, and can reduce the liquid residue in the surface sheet.

Although the invention is to be understood in more detail from the following detailed description and the accompanying drawings of the preferred embodiments of the invention, however, these are not intended to limit the invention but merely for the purpose of illustration and understanding.

1: is a top view which shows the sanitary napkin of embodiment of the absorbent article of this invention.

FIG. 2 is a cross-sectional view taken along the line II-II showing a state where the sanitary napkin shown in FIG. 1 is mounted on the crotch cloth of the underwear.

3 is an enlarged cross-sectional view showing the opening state of the liquid permeation hole and the installation state of the liquid acquisition layer.

4 is a perspective view of the liquid obtaining layer.

5A and 5B are cross-sectional views of the V-V line of FIG. 4, FIG. 5A shows a single layer structure, and FIG. 5B shows a multi-layer structure.

6 is a cross-sectional view taken along the line VI-VI of FIG. 4.

Fig. 7 is a perspective view of the upper mold for making the liquid acquisition layer three-dimensional.

8 is a perspective view of a lower mold for making a liquid acquisition layer three-dimensional;

FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 7.

10 is a cross-sectional view showing a state in which the liquid acquisition layer is three-dimensionally formed by the upper mold and the lower mold.

It is a top view which shows the vertically-long sanitary napkin as an absorbent article of the 2nd Embodiment of this invention.

It is a top view of the acryl plate used for a pressure absorption test, and FIG. 12B is sectional drawing explaining the said pressure absorption test.

In the present invention, there is provided an absorbent article having a liquid permeable surface sheet located on the skin side surface, a back sheet located on the side surface of the wear, and a liquid absorbing layer located between the surface sheet and the back sheet.

The liquid acquisition layer is provided on the surface of the liquid absorption layer facing the surface sheet, the liquid acquisition layer is maintained in a three-dimensionally deformed state,

The liquid acquisition layer is a three-dimensional deformation of the absorbent sheet, is convex toward the surface sheet, longitudinal ribs extending in parallel to each other in the longitudinal direction of the article, and convex toward the surface sheet, Having transverse ribs extending in the transverse direction of the article, the transverse ribs being spaced in the longitudinal direction and connecting between adjacent longitudinal ribs to create a plurality of recesses surrounded by the longitudinal ribs and the transverse ribs,

At least the longitudinal rib is in contact with the upper member, and the bottom of the recess is in contact with the liquid absorbing layer.

In the absorbent article of the present invention, the acupuncture points penetrating the surface sheet are temporarily held in the recesses formed in the liquid acquisition layer, but the liquid acquisition layer is a three-dimensional deformation of the absorbent sheet to increase its sheet thickness. Compared to the case where the embossed pattern is formed on the nonwoven fabric, the volume of the individual concave portions can be increased, and a large amount of menstrual blood can be temporarily maintained in the concave portions. Moreover, since the bottom portion of the concave portion obtained by deforming the absorbent sheet is in contact with the liquid absorbing layer, the acupuncture points in the concave portion can penetrate the absorbent sheet and immediately migrate to the liquid absorbing layer, thereby preventing long-term accumulation of acupuncture points in the concave portion. have. Further, since the longitudinal ribs extend in the longitudinal direction of the article, and the longitudinal ribs are in contact with a member located above the surface sheet or the liquid permeable layer, the liquid retained in the recess is guided toward the longitudinal direction, Diffusion becomes easy to be suppressed. Therefore, the menstrual blood easily penetrates into the liquid absorbing layer without causing leakage in the horizontal direction.

The liquid acquisition layer of this invention can be comprised so that the height dimension from the bottom part of the said recessed part to the top part of the said horizontal rib may be lower than the height dimension from the bottom part of the said recessed part to the top part of the said longitudinal rib.

In this configuration, even if a large amount of acupuncture points are given at one time in the concave portion, since the acupuncture points can move along the concave portions arranged in the vertical direction beyond the low horizontal ribs, the transverse diffusion (that is, the vertical length) Spread beyond the ribs) is easy to prevent.

For this purpose, each of the recesses preferably extends in the longitudinal direction rather than the horizontal direction.

Moreover, in this invention, it is preferable that the space volume of one recessed part is 8-80 mm <^3> .

If the space volume is in the above range, the concave portion can maintain a sufficient amount of menstrual blood until the menstrual blood with high viscosity fluid penetrates the liquid acquisition layer. Therefore, even if a large amount of acupuncture points are given in a short time, the acupuncture points are less likely to overflow from the concave portions, and the acupuncture points can be prevented from returning to the surface sheet and the acupuncture points can be prevented from spreading in the horizontal direction. have.

In this invention, the said liquid acquisition layer can be made to have the low density part which the space | interval between fibers widened by concentration of the tensile stress when the said water absorbing sheet is deformed three-dimensionally.

If the fiber density is partially lowered in the liquid acquisition layer, the menstrual blood temporarily held in the recess can be immediately transferred to the liquid absorbing layer.

Further, in the present invention, the liquid acquisition layer may have a width wider than that of the longitudinal ribs and a flat portion extending continuously in the longitudinal direction.

The flat portion is a region which is not subjected to the tensile force or the compressive force when molded into a three-dimensional shape, and the strength is not lowered. Further, the fiber density remains the original sheet material, and the density is lower than that of the longitudinal ribs or the like. Therefore, when assembling the absorbent article, the flat portion can be held to supply the liquid acquisition layer to the granulation step. In addition, since the flat portion having a lower density than the longitudinal ribs or the like extends in the longitudinal direction, the flat portion can function as a diffusion barrier for preventing the menstrual blood from spreading in the horizontal direction. Although this flat part may be provided in any position of a liquid acquisition layer, it is preferable that the said flat part is provided in the left and right both sides of a liquid acquisition layer in order to exhibit the function as the said diffusion prevention strip effectively. Moreover, the flat part may be provided in the front-back end of a liquid acquisition layer.

In the present invention, the liquid acquisition layer may be one in which a plurality of absorbent sheets are stacked and three-dimensionally deformed together. You may partially adhere these absorbent sheets.

When the liquid acquisition layer is composed of a plurality of absorbent sheets, the basis weight can be increased, the absorption retention ability of the liquid can be increased, and the strength of the longitudinal ribs and the horizontal ribs can be increased. In addition, the three-dimensional deformation causes a decrease in density and cracks in the wall portion of the concave portion of the liquid acquisition layer. However, if the wall portion is a multilayer structure, such decrease in density and cracks do not occur at only one place, and the strength of the wall portion is extremely extreme. The fall of phosphorus can be prevented. Therefore, even when the absorbent article is in a wet state, the shape of the recess can always be maintained.

Moreover, in this invention, when measured in the longitudinal direction, it is preferable that the tensile breaking strength at the time of drying of the said liquid acquisition layer is 2.5 N or more per 25 mm width.

In order to impart the strength and suitable absorbency to the liquid acquisition layer, the absorbent sheet is preferably formed of cellulose fibers and synthetic resin fibers. Having the above-mentioned strength makes it easy to maintain a three-dimensional shape even under pressure from the wearer's body, and can maintain the space volume of the recess for a long time.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is explained in full detail in preferable embodiment based on this invention with reference to an accompanying drawing. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be made without these specific details. In addition, in order to avoid that this invention may become meaninglessly obscure, a well-known structure is not shown in detail.

The absorbent article of the present invention is used as a sanitary napkin whose main purpose is to absorb menstrual blood excreted from vaginal openings of women. The surface facing the wearer's crotch of the two surfaces of the absorbent article is the skin side surface, and the surface on the opposite side is expressed as the wear side surface regardless of whether the wear is worn on the outside thereof.

The term longitudinal centerline as used herein means a line extending in the longitudinal direction by dividing the absorbent article in the transverse direction. In addition, in the following 1st Embodiment, although the line extended in the horizontal direction which divides an absorbent article in the longitudinal direction is made into the horizontal reference line, a horizontal reference line is not limited to this centerline. For example, a longitudinally long absorbent article suitable for women to wear at bedtime as in the second embodiment, wherein the wing portion is located in the front portion, and transversely across the longitudinal center at the portion touching the vaginal opening during wearing; The line extending in the horizontal direction is referred to as the horizontal reference line.

1 is a plan view showing the sanitary napkin 1 with the skin side surface facing upward as a first embodiment of the absorbent article of the present invention, and FIG. 2 is a state in which the sanitary napkin of FIG. 1 is attached to the crotch fabric of the underwear. 3 is an enlarged cross-sectional view showing a central region of the sanitary napkin, FIG. 4 is a perspective view showing a liquid obtaining layer, and FIG. 5A and FIG. 5B are 4 is a cross-sectional view taken along the line VV, and FIG. 6 is a cross-sectional view taken along the line VI-VI.

The sanitary napkin 1 has a right edge 1a and a left edge 1b extending in the longitudinal direction at an equidistant distance from the longitudinal center line (Oy-Oy), and from the horizontal reference line (Ox-Ox). It has the front edge 1c and the rear edge 1d of the convex curve shape which are equally spaced back and forth.

The right edge 1a and the left edge 1b protrude to both the left and right sides in a predetermined length range in the vertical direction including the horizontal reference line Ox-Ox, and wings 1A and 1A are formed in the protruding portion. It is.

As shown in the cross-sectional view of FIG. 2, the sanitary napkin 1 has a liquid-impermeable back sheet 2 appearing on the surface of the wearer side and a liquid-permeable surface sheet 3 appearing on the skin-side surface. . A liquid absorbing layer 4 is interposed between the back sheet 2 and the surface sheet 3. The liquid permeable layer 5 is provided below the surface sheet 3, and the liquid acquisition layer 6 is provided between the liquid permeable layer 5 and the liquid absorbing layer 4.

As for the sanitary napkin 1, at least the surface sheet 3 and the said liquid absorbing layer 4 are locally pressurized and heated, and the compression groove | channel 10 which appears in the skin side surface is formed. That is, this compression groove 10 is formed by embossing using a heating roll. In the state where the liquid absorbing layer 4 and the surface sheet 3 overlap, the heating roll of the smooth surface comes into contact with the surface of the liquid absorbing layer 4, and the heating has the convex portion of the embossed pattern on the surface of the surface sheet 3. The roll abuts, is pressed and heated to form a compression groove 10.

In the compressed groove 10, the liquid absorbing layer 4 and the surface sheet 3 are compressed to almost a film form, and a liquid absorbing layer than a region other than the compressed groove 10, although it is not a film. (4) The high density medium-density compression parts are alternately formed. The compressed groove 10 having the high density compression portion and the medium density compression portion is formed as a groove in which the skin side surface of the sanitary napkin 1 is recessed toward the back sheet 2 side.

As shown in Fig. 1, the compression grooves 10 are divided into respective compression grooves indicated by reference numerals 11 to 16.

The inner compression grooves 11 and 11 extending in the longitudinal direction are formed at positions equidistant from the longitudinal center line Oy-Oy to the right and the left. The inner compression grooves 11 and 11 are arcuate curves in which the convex side is directed to the longitudinal center line Oy-Oy so that the opposing interval becomes narrow in the horizontal reference line Ox-Ox portion. The inner compression groove 11 and the inner compression groove 11 are connected to each other by a front connection compression groove 12 and a rear connection compression groove 13. The front connection compression groove 12 has a curved shape with the convex side facing the front edge 1c, and the rear connection compression groove 13 has a curve shape with the convex side facing the rear edge 1d.

From the boundary between the inner compression grooves 11 and 11 and the front connection compression groove 12, the front extension compression grooves 14 and 14 extend further toward the front edge 1c. The front extension compression grooves 14 and 14 are arranged equidistant from side to side with respect to the longitudinal center line Oy-Oy. In addition, the rear extension compression grooves 15 and 15 extend further from the boundary between the inner compression grooves 11 and 11 and the rear connection compression groove 13 toward the rear edge 1d. The rearward extension compression grooves 15 and 15 are arranged equidistant from side to side with respect to the longitudinal center line Oy-Oy.

The inner compression grooves 11 and 11, the front connection compression grooves 12, the rear connection compression grooves 13, the front extension compression grooves 14 and 14, and the rear extension compression grooves 15 and 15 are all formed continuously. It is. In addition, a predetermined range of the skin-side surface of the sanitary napkin 1 is surrounded by the inner compression grooves 11 and 11, the front connection compression grooves 12 and the rear connection compression grooves 13, and the enclosed range. Is the central region 20. The central region 20 has a symmetrical shape with respect to the longitudinal center line (Oy-Oy), and is also symmetrical with respect to the horizontal reference line (Ox-Ox).

Outer compression grooves 16 and 16 are formed on the left and right outer sides of the inner compression grooves 11 and 11. These outer compression grooves 16 and 16 are formed in the range of predetermined length before and after the longitudinal direction centering on the said horizontal reference line Ox-Ox. The outer compression grooves 16 and 16 have a curved shape similar to those of the inner compression grooves 11 and 11, and are formed at regular intervals from the inner compression grooves 11 and 11.

As shown in Fig. 1, the liquid permeable layer 5 has an elongated strip shape in the longitudinal direction, and its edges 5a and 5a do not overlap with the inner compression grooves 11 and 11, and the inner side thereof. It is located inside the compression grooves 11 and 11. Further, the liquid permeable layer 5 extends beyond the front connecting compression grooves 12 to the front edge 1c, and extends beyond the rear connecting compression grooves 13 to the rear edge 1d. Thus, in part of the front connecting compression groove 12 and the rear connecting compression groove 13, the surface sheet 3, the liquid permeable layer 5 and the liquid absorbing layer 4 are compressed together.

The liquid acquisition layer 6 is rectangular, and both edges 6h and 6h are located outward from the inner compression grooves 11 and 11 in the horizontal direction near the horizontal reference line Ox-Ox. Further, the front edge 6i and the rear edge 6j are located longitudinally inward from the front connecting compression groove 12 and the rear connecting compression groove 13. Therefore, in the part of the inner compression grooves 11 and 11, the surface sheet 3, the liquid acquisition layer 6 and the liquid absorbing layer 4 are compressed together.

A plurality of liquid permeation holes 25 are regularly arranged in the central region 20. As shown in FIG. 3, the liquid permeation hole 25 is formed to penetrate through the surface sheet 3 to reach the liquid permeation layer 5, and preferably, the liquid permeation hole 25 is provided. It is formed through the liquid permeable layer 5 from the surface sheet 3. Moreover, in the part which deviates from the side edge 5a, 5a of the liquid permeable layer 5, the liquid permeation hole 25 is formed only in the said surface sheet 3. As shown in FIG.

The opening area of the liquid permeation hole 25 is 0.2 to 8 mm ² , and when it is circular as in this embodiment, the diameter of the liquid permeation hole 25 is 0.5 to 3.2 mm. The distance between the centers of adjacent liquid permeation holes 25 is 1.5 to 8 mm.

The surface sheet 3 and the liquid permeable layer 5 contain thermoplastic fibers which can be heat-sealed. In the state where the surface sheet 3 and the liquid permeable layer 5 overlap, the liquid permeation hole 25 is formed by inserting a heated needle or pin from the surface sheet 3 toward the liquid permeable layer 5 side. do. At this time, the thermoplastic fiber contained in the surface sheet 3 and the thermoplastic fiber contained in the liquid permeable layer 5 are fused together on the inner surface of the liquid permeation hole 5 and its periphery. Thereby, the opening shape of the liquid permeation hole 25 can be maintained, and the periphery of the opening of the liquid permeation hole 25 is reinforced by the liquid permeation layer 5. Moreover, since the surface sheet 3 and the liquid permeable layer 5 are heat-sealed, it is not necessary to adhere the surface sheet 3 and the liquid permeable layer 5 with an adhesive, and the permeation of liquid is inhibited by the adhesive. There is no work.

The surface sheet 3 is formed of an air through nonwoven fabric. This air-through nonwoven fabric is made of polyethylene terephthalate (PET) containing titanium oxide in the core portion, and the fiber is bonded by hot air using a core sheath type synthetic synthetic fiber in which the super portion is polyethylene (PE). About 60 g / m ² . In addition, most of the composite synthetic fibers constituting the surface sheet 3 is coated with a hydrophilic emulsion, the rest is coated with a water-repellent emulsion, these are mixed, the mixing ratio of the fiber coated with a water-repellent emulsion is 10 to 30 mass %to be. By uniformly including the fiber coated with the water-repellent emulsion in the surface sheet 3 so as to have a mixing ratio within the above range, the acupuncture points given to the surface sheet 3 can be suppressed from being excessively diffused in the surface sheet 3, Mainly, the liquid penetrating hole 25 penetrates the liquid absorbing layer 4.

However, the surface sheet 3 can transmit the menstrual blood toward the liquid permeable layer 5 even in a region other than the liquid permeable hole 25. In order to impart such a liquid permeation function to the surface sheet 3, it is preferable that the density of the surface sheet 3 is 0.12 g / cm <^3> or less, and the minimum is about 0.025 g / cm <^3> .

The liquid permeable layer 5 is formed of an air through nonwoven fabric formed of a core sheath composite synthetic fiber having a core portion polypropylene (PP) and a super portion polyethylene (PE). In the air through nonwoven fabric of the liquid permeable layer 5, all fibers are coated with a hydrophilic emulsion. That is, no fiber coated with a water repellent emulsion is included. In the embodiment shown in FIG. 3, the liquid permeable layer 5 is formed by stacking a plurality of air through nonwoven fabrics, and for example, one air through nonwoven fabric is folded and folded so that two sheets are stacked three sheets or four sheets. Is used. The basis weight of one aceru nonwoven fabric is about 15 to 50 g / m ² , and the basis weight of the entire liquid permeable layer 5 may be about 30 to 150 g / m ² , more preferably 50 to 100 g / m ² . m ² .

By making the basis weight of the liquid permeable layer 5 larger than the basis weight of the surface sheet 3, the surface sheet 3 with a low basis weight and a low density can be reinforced, and excessive wrinkles arise in the surface sheet 3 Or rupture of the liquid permeation hole 25 can be prevented.

The fiber density of the liquid permeable layer 5 is lower than the fiber density of the surface sheet 3 and is 0.016 to 0.08 g / cm ³ . For example, the surface sheet 3 is composed of fibers having a fineness of 2.2 dtex, and the liquid permeable layer 5 is composed of fibers having a fineness of 4.4 dtex. Since the density of the liquid permeable layer 5 is lower than that of the surface sheet 3, and the liquid permeable layer 5 is formed of fibers with a large fineness, the liquid permeable layer 5 can exhibit cushioning properties. Therefore, by providing the said liquid permeable layer 5 in the range of a constant width centering on a longitudinal center line (Oy-Oy), this range can contact a wearer's body smoothly.

The liquid acquisition layer 6 is three-dimensionally shaped as shown in FIG. 4 by an absorbent sheet 8 having a liquid absorption function, a transmission function, and shape retention. In this embodiment, the absorbent sheet 8 contains cellulose fiber and synthetic resin fiber. In this embodiment, an airlaid nonwoven fabric (airlaid) in which chemical pulp is used as the cellulose-based fiber, and a core sheath composite synthetic fiber having a core part of polyethylene terephthalate (PET) and a super value polyethylene (PE) is used as the synthetic resin fiber. Pulp). In this airlaid nonwoven fabric, the fibers are laminated in a space to form a web, and a binder such as an emulsion of an ethylene vinyl acetate copolymer is given to form a sheet having a binder content of 5 to 20% by mass.

In order to smoothly transfer the menstrual blood absorbed by the liquid obtaining layer 6 to the liquid absorbing layer 4, the absorbent sheet 8 preferably contains 20 mass% or more of the chemical pulp to the total of the fibers. . In addition, in order to be able to maintain the three-dimensional shape shown in FIG. 4 in the wet state including acupuncture points, it is preferable that the said synthetic resin fiber is also contained in the said absorptive sheet 8 20 mass% or more with respect to the total fiber. . That is, the preferable ranges of the mass ratio of the chemical pulp and synthetic resin fiber which form an absorbent sheet are 80: 20-20: 80.

In order to be able to hold | maintain the liquid acquisition layer 6 in the three-dimensional state shown in FIG. 4, it is preferable that the basic weight of the absorbent sheet 8 is 20-200 g / m <^2> . As the absorbent sheet 8 having a basis weight in this range, the airlaid nonwoven fabric may be used in a single layer structure, or may be folded in a two or three layer structure.

It is preferable that the tensile breaking strength at the time of drying of the liquid acquisition layer 6 of the three-dimensional shape of FIG. 4 is 2.5 N or more per 25 mm in width in both the X direction and the Y direction. This tensile breaking strength maintains each of the specimens of the liquid acquisition layer 6 elongated in the X and Y directions at a width of 25 mm at a chuck-to-chuck distance of 100 mm. , The maximum load measured when the chuck is widened to 100 mm / minute. In addition, it is preferable that the tensile strength at break measured in the wet state in which the artificial menstrual blood is absorbed in the liquid acquisition layer 6 described later is 20% or more of the tensile strength at drying, and more than 30%. desirable.

As long as it has a basis weight and tensile breaking strength in the said range, the liquid acquisition layer 6 becomes easy to maintain a three-dimensional shape at the time of drying and wet, and is repeatedly given by the recessed part of the liquid acquisition layer 6 Can function to maintain acupuncture points. The liquid acquisition layer 6 may be other than the said airlaid nonwoven fabric as long as it has a basis weight and tensile breaking strength in the said range.

For example, the airlaid nonwoven fabric which bonded only pulp with a binder may be sufficient. Alternatively, a spunlace nonwoven fabric may be obtained in which cellulose fibers and synthetic resin fibers are entangled with a water jet. Alternatively, a composite sheet in which a spunlace nonwoven fabric mainly composed of pulp and rayon, which are cellulose fibers, and an airthrough nonwoven fabric mainly composed of synthetic resin fibers, may be integrated with a water jet treatment or a heat seal. Similarly, the spunlace nonwoven fabric may be integrated with a point bond nonwoven fabric or a spunbond nonwoven fabric. Alternatively, the spunlace nonwoven fabric may be bonded to the apertured film.

In the case where the liquid acquisition layer 6 is formed of various kinds of fibers, when the content rate of the cellulose fibers is higher than the side facing the liquid absorbing layer 4 from the side facing the liquid permeable layer 5, Acupuncture points are easily drawn from the liquid permeable layer 5 into the liquid acquisition layer 6. On the contrary, when the content rate of a cellulose fiber is made high on the side toward the liquid absorption layer 4, it will become easy to transfer acupuncture points to the liquid absorption layer 4.

As shown in FIG. 4, the liquid acquisition layer 6 has the vertical rib 6a deformed so that the convex side may face the surface sheet 3, and the horizontal rib deformed so that the convex side may face the surface sheet 3 similarly. The rib 6b is formed. The vertical ribs 6a extend linearly in the vertical direction (Y direction), are positioned at equal intervals in the horizontal direction (X direction), and are formed parallel to each other. The horizontal ribs 6b are formed to connect adjacent longitudinal ribs 6a. The horizontal ribs 6b form a row, and in each row, the horizontal ribs 6b are formed in parallel at regular intervals in the vertical direction. However, between adjacent rows, adjacent horizontal ribs 6b are not positioned on the same line in the horizontal direction, and are arranged such that horizontal ribs 6b of one row and horizontal ribs 6b of adjacent rows are alternately positioned. It is.

In the portion surrounded by the longitudinal ribs 6a and the horizontal ribs 6b, the liquid acquisition layer 6 is recessed toward the liquid absorbing layer 4, and those divided into the longitudinal ribs 6a and the horizontal ribs 6b are The recess is marked 6c. This recessed part 6c is a longitudinally long shape longer in a Y direction than an X direction. In this manner, a plurality of the recesses 6c are regularly arranged in the liquid acquisition layer 6.

The liquid acquisition layer 6 has flat portions 6f and 6f having a constant width dimension Wa inward from both side edges 6h and 6h. The recesses 6c are not formed in these flat portions 6f and 6f. The flat portions 6f and 6f are wider than the vertical ribs 6a having the width dimension described later. Specifically, the width dimension Wa of the flat portion 6f is preferably 1.2 to 10 times the width dimension of the longitudinal rib 6a, and more preferably 2 to 5 times. In this embodiment, the flat parts 6f and 6f are formed in both sides of the liquid acquisition layer 6, and the said recessed part 6c is regular in the whole area | region sandwiched between the flat part 6f and the flat part 6f. Are arranged. Alternatively, flat portions may be formed at both ends of the liquid acquisition layer 6 so as to have a predetermined width inward from the front edge 6i and the rear edge 6j. In this case, the width dimension of the flat portion from the front edge 6i and the rear edge 6j is preferably 1.2 to 10 times the width dimension of the horizontal rib 6b, more preferably 2 to 5 times.

As shown in FIG. 6, the height dimension h1 from the lower surface of the recess 6c to the top of the longitudinal rib 6a extends from the lower surface of the recess 6c to the top of the horizontal rib 6b. It is higher than the height dimension h2. As shown in FIG. 3, the top of the longitudinal rib 6a is in contact with the lower surface of the liquid permeable layer 5 with a hot melt adhesive, and the lower surface of the recess 6c is attached to the hot melt adhesive. It adhere | attaches on the upper surface of the liquid absorption layer 4 by this. That is, the top of each longitudinal rib 6a is located on the same plane and abuts on the liquid permeable layer 5, and the bottom surface of each recess 6c is located on the same plane and placed on the liquid absorbing layer 4. I'm in contact. Further, the flat portions 6f and 6f of the liquid acquisition layer 6 are also adhered to the lower surface of the liquid permeable layer 5 with a hot melt adhesive.

The hot melt adhesive is randomly coated on the lower surface of the liquid acquisition layer 6 and a part of the upper surface of the liquid absorption layer 4, so that menstrual blood penetrates from the liquid transmission layer 5 to the liquid acquisition layer 6, Penetration of menstrual blood from the liquid acquisition layer 6 into the liquid absorption layer 4 is prevented from being inhibited by the hot melt adhesive.

As described above, since the top of the horizontal rib 6b is lower than the top of the vertical rib 6a, at least a part of the horizontal rib 6b is not adhered to the liquid permeable layer 5, A minute gap is formed between the top of the horizontal rib 6b and the liquid permeable layer 5.

As described later, the liquid acquisition layer 6 is shaped into a three-dimensional shape by sandwiching the flat absorbent sheet 8 between the forming rolls. When shaping in this three-dimensional shape, since a tensile stress concentrates on the wall part 6e of the recessed part 6c, the force which isolate | separates fibers from this wall part 6e acts, and this wall part 6e is lengthwise. A low density portion having a lower fiber density than the top of the rib 6a and the top of the transverse rib 6b and the bottom 6d of the recess 6c is produced. In addition, cracks may occur in the wall portion 6e due to concentration of the stress. In addition, at the top part of the vertical rib 6a and the bottom part 6d of the recessed part 6c, the fiber which forms the absorbent sheet 8 is pressed, and the fiber density is high in this part. In addition, since the pressure at the time of shaping | molding does not act on the flat part 6f, the flat part 6f is lower in density than the top part of the longitudinal rib 6a and the bottom part 6d of the recessed part 6c. .

In addition, the average density of the liquid acquisition layer 6 is higher than the surface sheet 3 and the liquid permeable layer 5 and lower than the fiber density of the liquid absorption layer 4 thereunder. Since the longitudinal rib 6a of the liquid acquisition layer 6 is in contact with the liquid permeable layer 5, and the bottom part 6d of the recess 6c is in contact with the liquid absorption layer 4, according to the density gradient, Acupuncture points tend to migrate from the surface sheet 3 past the liquid permeable layer 5 to the liquid acquisition layer 6, and also easily transfer from the liquid acquisition layer 6 to the liquid absorption layer 4. In addition, as described above, since the low-density portion in which the fiber is dropped or cracked exists in the wall portion 6e of the recess 6c of the liquid acquisition layer 6, the recess 6c is temporarily stopped. The acupuncture points can be quickly transferred to the liquid absorbing layer 4.

In order for the acupuncture points to rapidly transfer from the liquid permeable layer 5 to the liquid acquisition layer 6 and to be rapidly given from the liquid acquisition layer 6 to the liquid absorption layer 4, the average of the liquid acquisition layer 6 is averaged. density is the fiber density of the liquid absorbent layer (4) positioned under the 0.05~0.25 g / cm ³ are preferred, the liquid acquisition layer 6 is preferably 0.07~0.25 g / cm ^3.

The width dimension at the height position of (1/2) -h1 of the said longitudinal rib 6a is 2-10 mm, Preferably it is 2-6 mm, and of (1/2) -h2 of the horizontal rib 6b The width dimension at the height position is 2 to 10 mm, preferably 2 to 6 mm. In addition, the height h1 of the liquid acquisition layer 6 is 1.3 to 5 mm. In order that the acupuncture points which permeate | transmitted the surface sheet 3 can be made high enough in the recessed part 6c, the opening area in the height position of (1/2) -h2 of one said recessed part 6c is 5-20. It is preferable that it is mm <^2> , and it is preferable that the space volume of the recessed part 6c (the area X (thickness (h1)-thickness of a water absorbent sheet)) is 8-80 mm <^3> .

In addition, the aspect ratio (that is, the ratio of the dimension in the Y direction to the dimension in the X direction) at the height position of (1/2) · h2 of one concave portion 6c is preferably in the range of 1.1 to 10. Preferably it is 1.5-7, Most preferably, it is 2-5. If the aspect ratio is less than the above range, the function of guiding the acupuncture points obtained in the liquid acquisition layer 6 in the longitudinal direction is lowered, and there is a possibility that diffusion in the horizontal direction is increased, and if the aspect ratio exceeds the above range, the horizontal rib ( 6b) The space | interval between each other becomes wide too much, and when sufficient compressive force toward a horizontal direction is received from a thigh part etc., sufficient elastic restoring force in a horizontal direction cannot be exhibited.

In this liquid acquisition layer 6, horizontal ribs 6b are formed at intervals in the vertical direction. Therefore, the liquid acquisition layer 6 is applied to the sanitary napkin 1 when a bending force acts in the direction in which the front edge 1c and the rear edge 1d approach and the skin side surface is concave. It follows this deformation | transformation and becomes easy to bend. When the aspect ratio of the recessed part 6c is especially in the said range, the liquid acquisition layer 6 will become easy to bend in the said direction. By following the liquid acquisition layer 6 to the curvature deformation of the sanitary napkin 1, peeling of the interface of the liquid acquisition layer 6 and the liquid permeable layer 5 becomes difficult to occur.

As shown in FIG. 4, since the horizontal ribs 6b are alternately arranged in the horizontal direction (X direction), the liquid acquisition layer 6 is easy to bend in the vertical direction as described above. Further, since the height h2 of the horizontal ribs 6b is lower than the height h1 of the vertical ribs 6a, the liquid acquisition layer 6 has the side edges 6h and 6h approaching each other and further facing the skin side. It becomes easy to deform also in the direction where a surface becomes concave.

The liquid absorbing layer 4 is a synthetic absorbent polymer such as polyacrylate, polyacrylamide, maleic anhydride, or natural absorbent such as starch, cellulose, or the like in aggregates of pulp such as pulverized pulp, mercerized pulp, and crosslinked pulp. As the polymer is contained, one in which pulp, the synthetic absorbent polymer and the like are surrounded by hydrophilic tissue paper is used.

The back sheet 2 is a liquid impermeable and breathable sheet, and is a polyethylene (PE) film or a polypropylene (PP) film having fine ventilation holes. For example, by mixing an inorganic filler such as CaCO ₃ , BaSO _4, or the like into a plastic sheet and stretching the fine sheet, fine air holes are suitably dispersed and formed in a film, thereby improving air permeability. The film is about 15-50 micrometers in thickness.

As shown in FIG. 2, the impermeable sheets 30 and 30 are provided in the left and right both sides of the skin side surface. In the wing parts 1A and 1A, the impervious liquid sheets 30 and 30 are bonded to the back sheet 2 with a hot melt adhesive. At an equidistant side-to-side distance from the longitudinal center line (Oy-Oy), the impermeable sheets 30 and 30 are folded in two stacks, and an elastic member 32 extending in the longitudinal direction is bonded thereto. . By the elastic member 32, an elastic contractive force acts between the front portion and the rear portion of the sanitary napkin 1 to bend the sanitary napkin 1, and as a result, before and after the sanitary napkin 1 In the middle portion of the impermeable sheets 30 and 30 stand up to form the leakage preventing walls 31 and 31.

The impervious sheet is formed of a spunbond nonwoven fabric, a meltblown nonwoven fabric, or a composite nonwoven fabric laminated therewith.

The basis weight of the liquid absorbing layer 4 is the largest in the central region 20. The basis weight of the portion sandwiched by the inner compression grooves 11 and 11 and the outer compression grooves 16 and 16 is smaller than the central region 20. The basis weight of the liquid absorbing layer 4 in other portions is equal to or slightly smaller than the portion sandwiched by the inner compression grooves 11 and 11 and the outer compression grooves 16 and 16.

The preferred basis weight of the liquid absorbing layer 4 in the central region 20 is 400 to 1200 g / m ² , more preferably 500 to 1000 g / m ² . The preferred basis weight of the portion sandwiched by the inner compression grooves 11 and 11 and the outer compression grooves 16 and 16 is 300 to 900 g / m ² , and more preferably 350 to 600 g / m ² . Moreover, the preferable basis weight of the liquid absorbing layer 4 of other parts is 200-700 g / m <^2> , More preferably, it is 300-500 g / m <^2> .

As a result, as shown in FIG. 2, thickness becomes large in the center area | region 20, and in the center area | region 20, the skin side surface becomes a shape expanded large toward the wearer's body.

The length of the central region 20, that is, the longitudinal gap between the front linkage compression groove 12 and the rear linkage compression groove 13, is at least 50 mm. The width dimension W1 of the central region 20 on the horizontal reference line Ox-Ox shown in FIG. 2 is determined according to the width of the female genitalia. Since the average width of the crotch of a woman is about 30 mm, the width dimension W1 is preferably in the range of 15 to 50 mm, and more preferably in the range of 20 to 40 mm.

When attaching the sanitary napkin 1 to the wearer's body, the pressure-sensitive adhesive provided on the outer surface of the back sheet 2 is bonded to the inner surface of the crotch cloth 26 shown in FIG. 1A) is wound around both edges of the crotch fabric 26, and is bent toward the outer surface of the underwear, and the pressure-sensitive adhesive provided on the wear-side surface of the wing portions 1A and 1A is bonded to the outer surface of the crotch fabric 26.

As shown in Fig. 2, the sanitary napkin 1 is easily in close contact with the vaginal opening because the central region 20 is swollen toward the wearer's body. The surface sheet 3 located on the skin-side surface of the central region 20 is a low density air through nonwoven fabric, and a liquid permeable layer 5 of a bulky air through nonwoven fabric is provided thereunder. For this reason, the central region 20 can smoothly contact the wearer's body.

Acupuncture points excreted from the vaginal opening are mainly given in the central region 20. Since the surface sheet 3 is a low density nonwoven fabric, menstrual blood can penetrate into the surface sheet 3. However, since the fiber coated with the water-repellent emulsion is contained in the surface sheet 3, the diffusion of menstrual blood in the surface sheet 3 is suppressed. Since the liquid permeable layer 5 positioned below the surface sheet 3 has voids inside the air through nonwoven fabric, the menstrual blood passes through the voids of the liquid permeable layer 5 by gravity and is located below it. It falls to the liquid acquisition layer 6 made. However, most of the menstrual blood given to the central region 20 passes quickly through the liquid permeation hole 25 and falls directly toward the liquid acquisition layer 6.

The menstrual blood which has fallen to the liquid acquisition layer 6 is absorbed by the absorbent sheet 8 forming the liquid acquisition layer 6 and is given to the liquid absorption layer 4 positioned below it. When a large amount of acupuncture points are given to the surface sheet 3 at one time, the acupuncture points penetrate through the liquid permeation hole 25 and fall to the liquid acquisition layer 6, but this acupuncture points are recessed portions 6c of the liquid acquisition layer 6. ) Immediately accumulate. Therefore, even if the amount of excretion of acupuncture points is large, this does not stay in the surface sheet 3 or the liquid permeable layer 5 for a long time. Accordingly, the skin-side surface of the central region 20 can be maintained in a state close to dryness, and it is difficult to give a wet feeling or a muggy feeling to the crotch of the wearer.

The menstrual blood given to the recessed portion 6c of the liquid acquisition layer 6 is discharged from the bottom portion 6d of the recessed portion 6c and from the low density portion or the broken portion at the wall portion 6e of the recessed portion 6c. It is rapidly introduced into the absorbent layer 4. In addition, when a few of the concave portions 6c are given to the concave portion 6c in an amount greater than the volume of space, the acupuncture points move beyond the relatively low transverse ribs 6b to the concave portions 6c adjacent in the longitudinal direction. Further, the longitudinal ribs 6a extending in parallel in the longitudinal direction and partitioning both side portions of the recesses 6c are bonded to the liquid acquisition layer 6 because their top portions are in contact with and adhered to the liquid permeable layer 5. Therefore, menstrual blood is difficult to spread in the horizontal direction. Therefore, the acupuncture points given in large quantities are absorbed by the liquid absorbing layer 4 while sequentially moving to the recesses 6c arranged in the longitudinal direction.

In addition, the left and right sides of the liquid acquisition layer 6 become flat portions 6f and 6f extending in the longitudinal direction, which are lower in fiber density than the longitudinal ribs 6a. Therefore, even if the acupuncture points which transmit the liquid acquisition layer 6 to a horizontal direction (X direction) exist, it can block by the said flat part 6f, 6f. Therefore, the anxiety about leaking in the horizontal direction can be reduced.

For example, even if the menstrual blood has migrated further to the sides 6h and 6h of the liquid acquisition layer 6, or beyond the transverse direction, the menstrual blood is the inner compression grooves 11 and 11 or the outer compression grooves ( Since it stops by 16, 16, it can suppress the leakage of a liquid from the sanitary napkin 1 to a horizontal direction effectively.

Since the absorbent sheet 8 forming the liquid acquisition layer 6 contains synthetic resin fibers, it is possible to maintain a three-dimensional shape even in a wet state in which menstrual blood is absorbed. In addition, when the pressure acting on the central region 20 in the crotch of the wearer is removed, the original three-dimensional shape shown in FIG. 4 can be restored. In particular, since the vertical ribs 6a and the horizontal ribs 6b are provided, the liquid acquisition layer 6 is excellent in the elastic restoring function.

Next, the manufacturing method of the said sanitary napkin 1 is demonstrated.

First, the process of shaping the liquid acquisition layer 6 into the three-dimensional shape shown in FIG. 4 is demonstrated.

FIG. 7 is a perspective view of the upper mold 40 for forming the liquid acquisition layer 6, and FIG. 8 is a perspective view of the lower mold 50. 9 is a cross-sectional view taken along line IX-IX of the upper mold 40.

In the upper mold 40 shown in FIG. 7, a convex portion 41 forming a row and a groove portion 42 located between the adjacent rows of the convex portion 41 are formed. The convex part 41 and the groove part 42 are extended in the longitudinal direction (Y direction) together, and are formed in parallel with each other. In each row of the convex portions 41, recesses 43 are formed at intervals in the longitudinal direction (Y direction). In other words, the convex portions 41 and the concave portions 43 alternate in the vertical direction. The recessed part 43 arrange | positioned at one of the rows of the convex part 41 is located in the middle of the adjacent recessed part 43 arrange | positioned at the row of the convex part 41 adjacent to it. In other words, the concave portions 43 are alternately arranged between the rows of the adjacent convex portions 41.

As shown in FIG. 9, the vertically opposed end portions 41a of the convex portions 41 are rounded, and the height from the bottom face 42a of the groove portion 42 to the top of the convex portion 41 is increased. The dimension H1 is higher than the height dimension H2 from the bottom face 42a to the top of the recess 43.

In the lower mold 50 shown in FIG. 8, the groove part 52 located between the convex line part 51 and the adjacent convex line part 51 is formed. The convex line part 51 and the groove part 52 extend in the longitudinal direction (Y direction) in parallel with each other. The convex portions 41 of the upper mold 40 are arranged in the horizontal direction (X direction) at the same pitch as the grooves 52 of the lower mold 50.

The mating surface of the upper mold 40 and the mating surface of the lower mold 50 are heated to about 120 ° C. lower than the melting point of polyethylene at the beginning of the heart sheath composite synthetic fiber, as shown in FIG. 10. As such, the absorbent sheet 8 is sandwiched between the upper mold 40 and the lower mold 50. The upper mold 40 and the lower mold 50 are combined such that the convex portion 41 enters the groove portion 52 and the convex line portion 51 enters the groove portion 42. However, a slight clearance is maintained between the top of the convex portion 41 of the upper mold 40 and the bottom of the groove portion 52 of the lower mold 50, and the convex line portion of the lower mold 50 ( The upper mold 40 is not pressed against the lower mold 50 in a mated state such that a slight clearance is maintained between the top of 51 and the bottom of the groove 42 of the upper mold 40. It is.

As a result, as shown in FIG. 10, the longitudinal ribs 6a are formed by the convex line portions 51 of the lower mold 50, and the concave portions are formed by the convex portions 41 of the upper mold 40. 6c) is formed. In addition, the absorbent sheet 8 is lightly pressed by the recessed portion 43 of the upper mold 40, and the horizontal rib 6b is formed by the recessed portion 43.

In addition, planes 44 and 44 extending in the longitudinal direction are formed at both sides of the upper mold 40, and planes 53 and 53 extending in the vertical direction are formed at both sides of the lower mold 50. . Between the planes 44 and 44 and the planes 53 and 53, the flat portions 6f and 6f are formed without the absorbent sheet 8 being pressed.

The absorbent sheet 8 is sandwiched between the upper mold 40 and the lower mold 50 which are installed to leave a clearance in the mated state and heated to a temperature slightly below the melting point of the composite synthetic fiber. In this way, since the absorbent sheet 8 is molded, there is no film-like portion in the liquid acquisition layer 6 which completely melts and solidifies the fiber and hinders liquid permeation. In addition, the composite synthetic fibers are heated to a temperature that softens, thereby maintaining the three-dimensional shape shown in FIG. 4 after molding.

Since the recesses 6c of the liquid acquisition layer 6 are formed by being pressed by the protrusions 41 having a predetermined length and arranged at intervals in the longitudinal direction, the recesses 6c of the absorbent sheet 8 Tensile stresses in both the X and Y directions are concentrated in the portion forming the wall portion 6e. Therefore, the space | interval of a fiber becomes wide in the wall part 6e of the recessed part 6c, and a crack arises depending on a place. At this time, by pressing the convex line portion 51 continuous in the longitudinal direction to form the longitudinal ribs 6a, the fiber density can be made high at the top of the longitudinal ribs 6a, and the concave portion 6c is likewise. The fiber density of the bottom part 6d of () can also be made high. In addition, the fiber density at the top of the transverse rib 6b is also higher than the wall 6e.

When mass-producing the liquid acquisition layer 6, the upper mold 40 shown in FIG. 7 is formed on the roll surface such that the Y direction is the circumferential direction and the X direction is the axial direction, and the lower mold 50 shown in FIG. ) Is also formed on the roll surface such that the Y direction is the circumferential direction and the X direction is the axial direction. Both rolls face with clearance. The absorbent sheet 8 is supplied between the rolls to form the liquid acquisition layer 6.

The manufacturing process of the sanitary napkin 1 overlaps the surface sheet 3 and the liquid permeation layer 5, and forms the said liquid permeation hole 25. As shown in FIG. Next, the vertical ribs 6a and the flat portions 6f and 6f of the liquid acquisition layer 6 are bonded to the lower surface of the liquid permeable layer 5 with a hot melt adhesive. Further, the lower surface of the recess 6c of the liquid acquisition layer is bonded to the liquid absorbing layer 4 with a hot melt adhesive. In the state where the surface sheet 3, the liquid permeable layer 5, the liquid acquisition layer 6, and the liquid absorbing layer 4 overlap, the compressed groove 10 is formed. Thereafter, the back sheet 2 is laminated and bonded to the lower surface of the laminate, and the impermeable sheet 30 is bonded to the laminate so as to appear on the skin side surface.

Moreover, unlike the wall part 6e of the recessed part 6c, the flat part 6f, 6f which extends longitudinally in the both sides of the liquid acquisition layer 6 is formed without extending the distance between fibers, It has a certain degree of rigidity, and the density is uniform. Therefore, in the assembling process of the sanitary napkin 1, it is possible to convey the liquid acquisition layer 6, for example, by sucking the flat parts 6f and 6f on a suction belt and maintaining a three-dimensional shape.

The liquid acquisition layer 6 may be formed of one absorbent sheet 8, but may be formed by overlapping a plurality of absorbent sheets 8 with each other. FIG. 5B shows an example in which the liquid acquisition layer 6 is formed by superimposing two absorbent sheets 8A and 8B. Each of the two absorbent sheets 8A and 8B is formed of the same material as that of the absorbent sheet 8.

As described above, when the liquid acquisition layer 6 is formed into a three-dimensional shape, tension is applied to the wall portion 6e of the concave portion 6c to widen the spacing of the fibers, and cracks are formed depending on the place. However, when the liquid acquisition layer 6 is formed by stacking a plurality of absorbent sheets, the low-density portion or the damaged portion in each wall portion 6e becomes different from each other by the sheet. Therefore, the intensity | strength of the whole wall part 6e of the recessed part 6c can be prevented from falling excessively, and it is easy to restore | restore to an original three-dimensional shape after body pressure acts and it crushes in a flat state.

The plurality of absorbent sheets may be partially bonded to each other. When the plurality of absorbent sheets contain all the thermoplastic fibers, the fibers can be bonded by fusion of the fibers. Alternatively, the absorbent sheet may be bonded with an adhesive. As shown in FIGS. 7-10, when making the liquid acquisition layer 6 three-dimensional shape using the heated mold, the absorbent sheet can be adhere | attached by the pressure which does not become a film form by the heat of a mold. . Alternatively, the plurality of absorbent sheets may be thermally bonded with a dot-shaped adhesive portion before shaping the liquid acquisition layer 6 into a three-dimensional shape.

When joining a plurality of absorbent sheets, the joining site may be any one of the longitudinal rib 6a, the horizontal rib 6b, the wall portion 6e of the recess 6c, and the bottom portion 6d of the recess. Or the joining site may be formed in all the said parts at random. However, it is preferable that the liquid absorption sheets are bonded to at least the wall portion 6e of the recessed portion 6c.

If the adhesion part is provided in the part of the longitudinal rib 6a and the horizontal rib 6b, the skeletal structure of the longitudinal rib 6a and the horizontal rib 6b can be strengthened. As described above, in the wall portion 6e of the concave portion 6c, the fiber density is extremely low. However, if the adhesive portion is provided in the wall portion 6e, the rigidity of the concave portion 6c is increased to maintain the shape. Can be. In addition, when the adhesion part is provided in the bottom part 6d of the recessed part 6c, the density can be made high in the bottom part 6d, As a result, the menstrual blood given to the liquid acquisition layer 6 is recessed. It becomes possible to concentrate on the bottom part 6d of 6c, and to give it to the liquid absorption layer 4.

11 is a plan view showing the sanitary napkin 100 of the second embodiment of the absorbent article of the present invention. In addition, the part of the structure same as embodiment shown in FIG. 1 attaches | subjects the same code | symbol, and detailed description is abbreviate | omitted.

This sanitary napkin 100 is a long type suitable for use during bedtime and the like. The total length dimension in the longitudinal direction (Y direction) is almost 200 to 450 mm, and both edges 1a and 1b are formed of wings 1A, From the rear position of 1A to the rear edge 1d, the shape is expanded so as to gradually widen, and rear flaps 1B and 1B are formed to abut the buttocks of the wearer.

The inner side compression grooves 11 and 11 are formed in the skin side surface, and have the front part 11A, 11A, the inflection part 11B, 11B, and the back part 11D, 11D. The front portions 11A and 11A are convex arc curved patterns toward the longitudinal center lines Oy-Oy. The opposing space | interval of the inner compression grooves 11 and 11 becomes the largest in inflection part 11B, 11B. The rear portions 11D and 11D are gradually close to each other as they face the rear edge 1d and are connected to each other by a rear connecting compression groove 13A.

The portion surrounded by the inner compression grooves 11 and 11, the front connection compression grooves 12 and the rear connection grooves 13A is the central region 20. The center area | region 20 is the front center area | region 20A which the part fitted in the said front parts 11A and 11A opposes the vaginal opening, and the middle center area which the part fitted in the inflection parts 11B and 11B opposes the perineum part. 20B, and the part fitted in back part 11D, 11D is the back center area | region 20D which opposes the groove of an anus and a buttocks.

In addition, the outer compression grooves 16 and 16 shown in FIG. 1 are formed on the left and right outer sides of the front portions 11A and 11A of the inner compression grooves 11 and 11. Rear outer compression grooves 17 and 17 are formed at the left and right outer sides of the rear portions 11D and 11D of the inner compression grooves 11 and 11, and are connected to each other inside the rear edge 1d.

In this embodiment, the liquid permeable layer 5 is formed in a band form from the front edge 1c to the rear edge 1d, and is provided in the center region 20 in the same solid as that shown in FIG. 4. The liquid acquisition layer 6 of the shape is provided.

In this embodiment, the length of the center region 20, that is, the longitudinal gap from the front coupling compression groove 12 to the rear coupling compression groove 13A is 120 to 350 mm, and the liquid acquisition layer 6 is It is provided in the front center area | region 20A which is a part which opposes at least the vaginal opening. Alternatively, as shown in FIG. 11, the liquid acquisition layer 6 may be provided over the front center region 20A and the middle center region 20B facing the perineal region.

Example

Each layer below is formed.

(a) surface sheet (3)

An air-through non-woven fabric made of a sheath type composite synthetic fiber (fineness 2.2 dtex, fiber length 44 mm) in which a polyethylene terephthalate containing titanium oxide at a ratio of 1.1% of the fiber mass is formed at the core and polyethylene at the beginning, and the base weight is 25 g. / m ² was used. In the following measurement, the surface sheet 3 was 130 mm in width, 200 mm in length, and 0.637 g in weight.

(b) liquid permeable layer (5)

Air through nonwoven fabric (core weight 20 g / m ² , average thickness 1.75 mm, average density of eccentric composite synthetic fibers (fineness 4.4 dtex, fiber length 50 mm), eccentric in cross-section with a core part polypropylene and a super part polyethylene) 0.0175 g / cm ³ ) was used. The fabric was folded into three layers and used. In the following measurement, the liquid permeable layer 5 was 100 mm in width, 200 mm in length, and 0.415 g in weight.

(c) liquid permeation hole (25)

The surface sheet 3 and the liquid permeable layer 5 overlap with each other, and a roll having a fin of 100 ° C. and a 70 ° C. roll having a hole into which the pin enters, and penetrates the liquid permeable layer 5 from the surface sheet 3. The liquid permeation hole 25 was formed. The opening diameter of the liquid permeation hole 25 was 2 mm, and the pitch was 5.5 mm in the Y direction, and 3.5 mm in the X direction.

(d) liquid acquisition layer (6)

60 mass% of chemical pulp, 26 mass% of core sheath-type composite synthetic fibers (fineness 1.7 dtex, fiber length 13 mm) having a core part of polyethylene terephthalate and super-addition polyethylene, and 14 mass% of an emulsion adhesive of ethylene vinyl acetate copolymer As the airlaid nonwoven fabric (airlaid pulp), a basis weight of 40 g / m ² was used. The fabric was folded into two stacks and used as the absorbent sheet 8. In the following measurement, the liquid acquisition layer 6 was 50 mm in width, 100 mm in length, and 0.205 g in weight.

The comparative example 1 of Table 1 was used as the liquid acquisition layer 6 as it is, without deforming the said water absorbing sheet 8 in three dimensions. The average thickness of the five measurements of the absorbent sheet 8 in a dry state was 0.928 mm.

The average density of the absorbent sheet 8 before molding in three dimensions was 0.075 g / cm ³ . Tensile strength at break in drying in the Y and X directions measured after the liquid acquisition layer 6 had become three-dimensional was 3.46 N / 25 mm and 2.83 N / 25 mm, respectively.

The absorbent sheet 8 was three-dimensionally formed to obtain a liquid acquisition layer 6. Width dimension at height of h1 / 2 of longitudinal rib 6a is 3 mm, width dimension at height of h2 / 2 of horizontal rib 6b is 2.5 mm and recessed portion 6c at height position of h2 / 2 ), The opening area was set to 15 mm ² .

However, in each of Comparative Example 2 and Examples 1 to 8 shown in Table 1, the clearance between the upper mold 40 and the lower mold 50 was changed to allow the liquid acquisition layer 6 to be dried. The thickness of (h1 of FIG. 6) was changed.

In the comparative example 2, since the said thickness was 1.192 mm, the space volume of the recessed part 6c was {15 * (1.192-0.928)} = 3.96 mm <^3> . In the same manner, the space volume was 8.61 mm ^{3 in} Example 2 having the smallest thickness among Examples 1 to 8, and 32.64 mm ^{3 in} Example 8 having the largest thickness. That is, the space volume of the recessed part in Examples 1-8 was 8.61-32.64 mm <^3> .

(e) Liquid absorbing layer 4

8 g of chemical pulp and 0.15 g of absorbent polymer were uniformly mixed, and a laminate of 0.069 g / cm ³ having a density of 70 mm in width and 200 mm in length and surrounded by 15 g / m ² of tissue paper was applied to the liquid absorbing layer (4). It was made.

(1) measurement of thickness

The thickness was measured by UF-60A by the Daiegaku Chemical Co., Ltd. product after the pressurization at the time of drying and wet conditions.

(2) drip test

Each of the liquid acquisition layers 6 of Comparative Examples 1 to 2 and Examples 1 to 8 of Table 1 is fixed to an opening of a beaker having a volume of 50 ml. 5 mm away from the center of the liquid acquisition layer 6, artificial acupoints are continuously dropped at a flow rate of 3 ml / min using an auto burette. Then, after starting the drop, the time until the first drop of artificial menstrual blood dropped in the beaker first was measured (unit is seconds).

Here, artificial menstrual blood is stirred by adding 300 g of glycerin, 30 g of sodium salt of carboxymethylcellulose, and 40 g of sodium chloride to 4 liter of ion-exchanged water to obtain a solution, and coloring the solution with food red. One was used.

(3) pressure absorption test

As shown in Fig. 12B, on the flat test bench 61, the liquid absorbing layer 4, the liquid acquiring layer 6, and the liquid permeable layer 5 and the surface sheet 3 are integrally named. Overlap The acrylic plate 62 of the dimension shown in FIG. 12A is provided on a laminated body so that the opening part 62a may match the center of a laminated body. And 900 g of weights 63 and 63 are mounted before and behind the opening part 62a, respectively. The weight of the acrylic plate was 115 g.

The artificial menstrual blood is applied to the opening 62a at a flow rate of 95 ml / min using an auto burette. At the first time, 3 ml of artificial acupuncture points are given, and the time (seconds) from the start of supplying the liquid until the liquid disappears on the surface of the surface sheet 3 in the opening portion 62a is measured. After 30 seconds have elapsed since the first liquid on the surface of the surface sheet 3 disappeared, 4 ml of artificial menstrual blood was applied and the penetration time was measured in the same manner. After the second liquid disappears from the surface of the surface sheet 3, after 5 minutes, 3 ml of artificial acupuncture points are applied, and the penetration time is measured in the same manner.

After 1 minute has elapsed since the liquid finally supplied from the surface of the surface sheet 3 is peeled off, the acrylic plates 62 and the weights 63 and 63 are peeled off, and the thickness of the liquid acquisition layer 6 is measured. (Thickness in the dry state after thickness / shaping | molding after a pressure absorption test) was computed as thickness change rate (%).

The measurement results are shown in Table 1 below.

From Table 1, it was confirmed in Examples 1 to 8 that the liquid permeability in the drip property and the pressure absorbency test was good.

While the invention has been shown and described with respect to its embodiments, it will be apparent to those skilled in the art that the foregoing and other modifications, omissions, and additions can be made without departing from the spirit and scope of the invention. For example, in the said embodiment, although the liquid guide layer 5 was arrange | positioned between the surface sheet 3 and the liquid acquisition layer 6, the said liquid acquisition layer 6 is not provided without providing the liquid guide layer 5; It may be in direct contact with the surface sheet 3. Accordingly, the present invention should not be construed as limited to the specific embodiments set forth herein, and with respect to the features set forth in the appended claims, all possible embodiments that may be embodied within the scope and equivalents thereof encompassed therein. It will include.

As described above, in the present invention, when a large amount of liquid is given at a time, the liquid can be immediately absorbed by the liquid absorbing layer after being kept under the surface sheet, and the liquid remaining in the surface sheet can be prevented.

Claims (8)

The liquid permeable surface sheet 3 located on the skin side surface, the back sheet 2 located on the wearing side surface, and the liquid absorbing layer 4 positioned between the surface sheet 3 and the back sheet 2. In an absorbent article having) The liquid acquisition layer 6 is provided on the surface of the liquid absorbing layer 4 facing the surface sheet 3, and the liquid acquisition layer 6 is maintained in a three-dimensionally deformed state, The liquid acquisition layer 6 includes a longitudinal rib 6a in which the absorbent sheet 8 is three-dimensionally deformed, convex toward the surface sheet 3 and extending in parallel to each other in the longitudinal direction of the article, and It has convex toward the surface sheet 3 and has transverse ribs 6b extending in the transverse direction of the article, wherein the transverse ribs 6b are arranged at intervals in the longitudinal direction and adjacent longitudinal ribs 6a ), To make a plurality of recesses 6c surrounded by the vertical ribs 6a and the horizontal ribs 6b, At least the longitudinal rib (6a) is in contact with the upper member, and the bottom (6d) of the recess (6c) is in contact with the liquid absorbing layer (4). The height dimension h2 from the bottom part 6d of the said recessed part 6c to the top part of the said horizontal rib 6b is determined from the bottom part 6d of the said recessed part 6c. An absorbent article, which is lower than the height dimension h1 to the top of the longitudinal rib 6a. The absorbent article as set forth in claim 1, wherein each of the recesses (6c) extends longer in the longitudinal direction than in the transverse direction. The absorbent article as set forth in claim 1, wherein the space of one recessed portion (6c) is 8 to 80 mm ³ . 2. The absorbent article as set forth in claim 1, wherein said liquid acquisition layer (6) has a low density portion in which the spacing between fibers is widened by concentration of tensile stress when the absorbent sheet (8) is three-dimensionally deformed. The liquid absorbing layer (6) according to claim 1, wherein the liquid obtaining layer (6) is formed with a flat portion (6f) having a width (Wa) wider than that of the longitudinal ribs (6a) and extending continuously in the longitudinal direction. article. The absorbent article as set forth in claim 1, wherein the liquid obtaining layer (6) is formed by stacking a plurality of absorbent sheets (8A, 8B) and being three-dimensionally deformed together. The absorbent article as set forth in claim 1, wherein when measured in the longitudinal direction, the tensile strength at break in drying the liquid acquisition layer (6) is 2.5 N or more per 25 mm width.