JP2009153879A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article having liquid absorbing property instantaneously separating large volume of liquid from a body in a short time and having superior shape stability. <P>SOLUTION: This absorbent article is disposed with a liquid-permeable surface sheet in a skin contact face side, a back side sheet in a skin non-contact face side, and an absorber between the both sheets, wherein the surface sheet is made of nonwoven fabric, the absorber contains primarily pulp fiber, the surface sheet and absorber are superposed, the superposed surface sheet and the absorber are formed with projections projecting from the back side sheet side to the skin contact face side, and recesses to become the bases, each projection has an apex, the projection cross section passing through the apex has an arch shape, the surface sheet is joined with the absorber at the projection apexes and the projection side wall parts, and the thickness of the surface sheet from the side wall part of the projection to the base of the recess is gradually heightened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an absorbent article, and more particularly to an absorbent article suitable for sanitary napkins and the like.

Surface sheets for absorbent articles such as sanitary napkins are required to have surface properties that do not irritate the skin of the wearer while simultaneously absorbing absorbed fluid such as menstrual blood and urine. The Conventionally, as a surface sheet for absorbent articles, those made of various non-woven fabrics, those perforated thereon, perforated films made of synthetic resins such as polyethylene have been used. In recent years, in order to improve the liquid absorbency and appearance of an absorbent article, various products with further improved structures have been proposed. One example is an absorbent article having a groove (embossed) surface.
Groove (embossing) processing is a processing method in which the absorbent body is subjected to heat compression treatment, and a heat compression portion and a non-compression portion are provided on the surface. By this technique, attempts have been made to change the liquid absorptivity of the surface portion of the absorbent article, prevent liquid bleeding and twisting, and control the fluidity of the liquid (Patent Documents 1 to 3). reference). However, the heat compression process represented by grooving has the effect of increasing the degree of adhesion with the surface material and extending the absorption rate to some extent by extending the top sheet in the absorber depth direction. No one has yet been developed to satisfy both the absorption performance and the above-mentioned surface properties that can instantly separate the body from the body.

JP 2000-262558 A JP 2001-178768 A Japanese Patent No. 2620305

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an absorbent article that has liquid absorptivity that allows a large amount of liquid to be instantaneously separated from the body in a short time and that is excellent in shape stability.

  The present invention relates to an absorbent article in which a liquid-permeable surface sheet is provided on the skin contact surface side, a back sheet is provided on the non-skin contact surface side, and an absorbent body is disposed between the two sheets. The absorbent body contains a pulp fiber as a main component, the top sheet and the absorbent body are overlaid, and the superposed topsheet and absorber are both from the back sheet side to the skin contact surface side. A protruding convex portion and a concave portion serving as a bottom surface are formed, the convex portion has a vertex, a sectional shape of the convex portion passing through the vertex is an arch shape, and the topsheet and the absorber are the convex The above object is achieved by an absorbent article that is joined to the absorber at the apex of the protrusion and the side wall of the protrusion, and further, the thickness of the topsheet gradually increases from the side wall of the protrusion to the bottom of the recess.

  The absorbent article of the present invention has a liquid absorptivity that allows a large amount of liquid to be instantly separated from the body in a short time, is excellent in shape stability, and further provides shape stabilization and speed absorption at the same time. be able to.

Hereinafter, the absorbent article of this invention is demonstrated in detail, referring drawings based on the preferable embodiment.
FIG. 1 is a perspective view showing in cross section two sides of the absorbent article of the present invention. The absorbent article of this embodiment includes a liquid-permeable top sheet 1 on the skin contact surface side, a back sheet 2 on the non-skin contact surface side, and an absorbent body 3 disposed between the two sheets. Have. The top sheet 1 and the absorbent body 3 are overlaid, and the overlaid top sheet 1 and the absorbent body 3 both protrude from the upper skin contact surface side in FIG. Specifically, the convex part 4 which protrudes from the back surface sheet 2 side to the skin contact surface side, and the recessed part used as a bottom part are formed.

The top sheet 1 has liquid permeability and is made of a nonwoven fabric. Examples of the nonwoven fabric include various types such as an air-through nonwoven fabric, a spunbond nonwoven fabric, a meltblown nonwoven fabric, and a spunlace nonwoven fabric manufactured by the card method.
However, the fiber surface needs to be hydrophilic. When using fibers made of synthetic resin such as polyethylene, polypropylene, and polyester, the surface of the fiber should be hydrophilized using a surfactant or the like. It is preferable to apply. The surfactant used for the hydrophilization treatment is not particularly limited as long as it is a hydrophilic surfactant having a hydrophilic group and a lipophilic group, but an anionic surfactant and an ethylene oxide-based addition mole number is high. Nonionic surfactants are preferred. Specifically, sulfosuccinic acid ester, alkyl ether sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, glycerin fatty acid ester and the like are preferable.

Moreover, it is more preferable to use the heat-extensible fiber mentioned later as a nonwoven fabric fiber material. The fineness of the constituent fibers is preferably 1 to 20 dtex, more preferably 1.5 to 4 dtex, from the viewpoint of securing the strength of the surface sheet and improving the touch.
Preferably the basis weight of the topsheet 1 is 10 to 50 g / ^{m 2,} and more preferably 15 to 40 g / ^{m 2.} This is a preferable range from the viewpoint of absorbability, wearing feeling, and economy.

  In the absorbent article of the present invention, the fibers forming the nonwoven fabric of the topsheet 1 are the first to have a bulky fiber, for example, a crimped fiber that has been mechanically deformed into a crimp shape, a predetermined treatment such as heat. Latent crimped fiber that starts shrinking and deforms into a crimp shape, fiber that deforms bulky when the core is decentered with a core-sheath type composite fiber, and the apparent fiber length is extended by performing a predetermined treatment It is preferable to use fibers or the like. Among these, it is particularly preferable to use a heat-extensible fiber that exhibits elongation behavior by heat treatment. Examples of the heat-extensible fibers include a first resin component and a second resin component having a melting point or softening point lower than the melting point of the first resin component, and the second resin component is at least part of the fiber surface. Is preferably a bicomponent composite fiber that is continuously present in the length direction. There are various forms of the composite fiber such as a core-sheath type and a side-by-side type, and any form is included in the present invention.

  The back sheet 2 used on the non-skin contact surface side of the absorbent article is not particularly limited as long as it has a function of preventing liquid leakage. The material of the back sheet 2 is not particularly limited as long as it has waterproofness. For example, a resin made of a polyolefin-based thermoplastic resin such as polyethylene or polypropylene or a mixture thereof, polyurethane resin, polyester resin, and paper And a composite material of a hydrophobic or hydrophilic nonwoven fabric made of a thermoplastic resin and the above-described resin film. Further, the material for forming the back sheet 2 to be water vapor permeable is not particularly limited as long as it is waterproof and water vapor permeable. However, calcium carbonate may be used as a thermoplastic resin made of polyethylene, polypropylene, or a mixture thereof. A porous film obtained by melt-mixing a minute inorganic filler made of, for example, barium sulfate or the like, and forming the film uniaxially or biaxially, sized waterproof paper, meltblown, etc. And water-repellent nonwoven fabric obtained by the above manufacturing method, porous films, waterproof paper, composite sheets of nonwoven fabric composed of hydrophobic fine thermoplastic fibers, and the like. Although the thickness of a back surface sheet is not specifically limited, 10-300 micrometers is preferable and 20-50 micrometers is more preferable. If it is less than 10 μm, it is difficult to obtain sufficient strength of the liquid-impermeable sheet 2, and there is a possibility that the liquid-impermeable sheet 2 is torn during use or desorption. On the other hand, if it exceeds 300 μm, the liquid-impermeable sheet 2 becomes too hard, and there is a possibility that the wearing feeling is impaired.

  The absorber 3 contains pulp fibers as a main component, and is preferably formed from pulp fibers obtained by defibrating natural fibers. Here, the natural fiber refers to a natural plant-derived fibrous substance. Examples of the pulp fibers contained in the absorbent body 3 include natural cellulose fibers such as wood pulp, cotton pulp, and straw pulp, and regenerated cellulose fibers such as rayon and cupra. Hydrophilic fibers such as polyvinyl alcohol fibers and polyacrylonitrile fibers. It may be combined with a synthetic fiber. The content of the synthetic fiber used is preferably 30% or less by mass with respect to the pulp fiber.

  Moreover, the absorber 3 may contain the superabsorbent polymer as a subcomponent. As the superabsorbent polymer, a polymer that can absorb and retain a body fluid 20 times or more of its own weight and can gelate is preferable. Examples thereof include starch, crosslinked carboxylmethylated cellulose, a polymer of acrylic acid or an alkali metal acrylate or a copolymer thereof, polyacrylic acid and a salt thereof, and a polyacrylate graft polymer. As the polyacrylate, sodium salt is preferable.

The basis weight of the absorbent layer 3 is preferably from 50 to 500 g / ^{m 2,} and more preferably 50 to 300 g / ^{m 2.} All of these are preferable ranges from the viewpoints of absorbability, wearing feeling, and economy. Moreover, when the absorber 3 contains a superabsorbent polymer as an auxiliary component, the basis weight of the superabsorbent polymer is in the range of 10 to 100 g / m ² . From the viewpoint of

  It is preferable that the surface sheet 1 and the absorber 3 are integrally joined to form a sheet-like composite material. In the present invention, “integrated and joined” means that the paper layer and the perforated film are not inserted between the surface layer and the absorbent layer so that the surface layer and the absorbent layer are substantially in contact with each other, It is preferable to form a concavo-convex structure by thermocompression bonding means. At this time, a functional sheet may be provided between the surface layer and the absorbent layer as long as the liquid absorbency is not hindered.

  In the embodiment shown in FIG. 1, the top sheet 1 and the absorbent body 3 are overlaid, and the top surface sheet 1 and the absorbent body 3 that are overlaid both protrude from the back sheet side 2 to the skin contact surface side and the bottom surface. A recess is formed. And it is preferable that the vertex 1a of the convex part in the surface sheet 1 is provided just above the vertex of the convex part of the absorber 3. FIG. In addition, although the convex part 4 of what was shown in FIG. 1 is a mountain shape or a hump shape, it is not restricted to this shape, The wall-like convex part which these several continued may be sufficient.

The thickness of the absorbent article is preferably 1 to 10 mm, preferably 1 to 5 mm in terms of the shortest distance from the non-skin contact surface of the back sheet 2 to the apex 1a of the convex portion of the top sheet 1. Is more preferable. If the thickness is too thin, it is difficult to design a sufficient absorption capacity for leakage, and there is a possibility of causing discomfort to the skin such as liquid return and dirt. Moreover, since formation of the convex part 4 cannot fully be performed, integration of the surface sheet 1 and the absorber 3 becomes inadequate. If the thickness is too thick, the thickness of the absorbent article leads to a sense of incongruity and the wearing feeling is impaired. When the concavo-convex structure is formed, this tendency becomes more remarkable, or the moldability of the convex portion 4 becomes difficult. The height of the absorber 3 is preferably 0.3 to 10 mm, and more preferably 0.3 to 6 mm, on the skin contact surface side. If the height is too low, it is not possible to obtain a sufficient gap that allows moisture to escape and prevent stuffiness. On the other hand, if the height is too high, the convex height becomes uncomfortable and the wearing feeling is impaired. Moreover, about the height of the convex part 4, it is preferable that the height difference by the side of a skin contact surface shall be 0.5-10 mm, and it is more preferable to set it as 0.5-8 mm. If the height is too low, the texture of the non-woven fabric may be impaired. If the height is too high, the convex height becomes uncomfortable and the wearing feeling is impaired.
The interval between the protrusions 4 is not particularly limited, but in terms of the number of protrusions per unit area, it is preferably 1 to 9 and more preferably 1 to 5 per 1 cm ² . In particular, when the number exceeds 9 per 1 cm ^{2, the} entire absorbent article becomes hard and the wearing feeling may be impaired.

Hereinafter, the heat-extensible conjugate fiber used suitably for the top sheet 1 will be described in more detail.
The first resin component is preferably a component that expresses the heat extensibility of the fiber, and the second resin component is preferably a component that expresses heat-fusibility. The first resin component preferably has an orientation index of 30 to 60%, more preferably 35 to 55%. On the other hand, the second resin component preferably has an orientation index of 40% or more, and more preferably 50% or more. The upper limit value of the orientation index of the second resin component is not particularly limited and is preferably as high as possible, but is usually about 70%. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber. And when the orientation index of a 1st resin component and a 2nd resin component is each said value, favorable heat | fever extensibility can be given to a heat | fever extensible composite fiber.

  As the heat-extensible composite fiber, a core-sheath type or a side-by-side type can be used as described above. As the core-sheath type heat-extensible composite fiber, a concentric type or an eccentric type can be used. In particular, the core-sheath type is preferable. In this case, it is preferable that the first resin component constitutes a core and the second resin component constitutes a sheath from the viewpoint of increasing the thermal elongation rate of the thermally extensible composite fiber. There is no restriction | limiting in particular in the kind of 1st resin component and 2nd resin component, What is necessary is just resin with fiber formation ability. In particular, the difference between the melting points of the two resin components, or the difference between the melting point of the first resin component and the softening point of the second resin component is 20 ° C. or more, particularly 25 ° C. or more. This is preferable because it can be performed. When the heat-extensible conjugate fiber is a core-sheath type, a resin having a melting point of the core component higher than the melting point or softening point of the sheath component is used. The first resin component preferably has crystallinity. Resin having crystallinity is a general term for resins that are melt-spun and stretched to the extent that they are normally carried out, and it is a general term for resins that produce sufficient orientation and crystals. Is a resin that can be defined. As a preferable combination of the first resin component and the second resin component, as the second resin component when the first resin component is polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), Examples thereof include polyethylene such as linear low density polyethylene (LLDPE), ethylene propylene copolymer, and polystyrene. When a polyester resin such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) is used as the first resin component, polypropylene (PP) is added as the second component in addition to the example of the second resin component described above. And copolyester. Furthermore, examples of the first resin component include polyamide-based polymers and two or more types of copolymers of the first resin component described above, and examples of the second resin component include two or more types of the second resin component described above. Copolymers are also included. These are appropriately combined.

  A particularly preferred combination of the first resin component and the second resin component is a combination in which the first resin component is polypropylene and the second resin component is polyethylene, particularly high-density polyethylene. This is because the non-woven fabric can be easily manufactured because the difference in melting point between both resin components is in the range of 20 to 40 ° C. In addition, since the specific gravity of the fiber is low, a nonwoven fabric that is lightweight and excellent in cost and can be incinerated and discarded with a low heat quantity is obtained. Further, by using this combination, the heat stretchability of the heat stretchable conjugate fiber is also increased. The reason is considered as follows. In said heat extensible composite fiber, the orientation coefficient of the 1st resin component is restrained in the specific range, and the orientation coefficient of the 2nd resin component is raised. Polyethylene, which is the second resin component, particularly high-density polyethylene, has high crystallinity. Therefore, until the heat-extensible composite fiber is heated and the temperature reaches the melting point of polyethylene, the heat elongation of the fiber is restrained by the polyethylene. When the fiber is heated to the melting point of polyethylene or higher, the polyethylene begins to melt and the constraint is released, so that the first resin component, polypropylene, can be stretched, and the entire fiber is thought to stretch.

A preferable combination of polypropylene and polyethylene is preferably the following (1), particularly (2). By adopting such a combination, the polyethylene as the second resin component is easily oriented during melt spinning, the crystallinity thereof is increased, and the polypropylene of the first resin component is appropriately oriented, so that the fiber Increases thermal extensibility.
(1) Polypropylene having a melt flow rate (hereinafter also referred to as MFR) of 10 to 35 g / 10 min and a Q value of 2.5 to 4.0 is used, and polyethylene has an MFR of 8 to 30 g. A combination using a Q value of 4.0 to 7.0 at / 10 min.
(2) Polypropylene having an MFR of 12 to 30 g / 10 min and a Q value of 3.0 to 3.5 is used, and polyethylene has an MFR of 10 to 25 g / 10 min and a Q value of 4 Combinations using .5 to 6.0.

  The MFR of polypropylene is measured at a temperature of 230 ° C. and a load of 2.16 kg according to JISK7210. Similarly, the MFR of polyethylene is measured according to JISK7210 at a temperature of 190 ° C. and a load of 2.16 kg.

The melting point of the first resin component and the second resin component was determined by using a differential scanning thermal analyzer DSC-50 (manufactured by Shimadzu Corporation) and performing thermal analysis of a finely cut fiber sample (sample mass 2 mg) at a heating rate of 10 ° C. / The melting peak temperature of each resin is measured and defined by the melting peak temperature.
When the melting point of the second resin component cannot be clearly measured by this method, the temperature at which the second resin component is fused to such an extent that the fiber fusion point strength can be measured as the temperature at which the second resin component begins to flow. Is the softening point.

The ratio (weight ratio) between the first resin component and the second resin component in the heat-extensible conjugate fiber is preferably 10:90 to 90: 10%, particularly 30:70 to 70: 30%. Within this range, the mechanical properties of the fiber are sufficient, and the fiber can withstand practical use. Further, the amount of the fusion component is sufficient, and the fibers are sufficiently fused. An appropriate value is selected as the thickness of the heat-extensible conjugate fiber depending on the specific use of the conjugate fiber. A general range is 1.0 to 10 dtex, particularly 1.7 to 8 dtex, from the viewpoints of fiber spinnability and cost, card machine passability, productivity, cost, and the like.
As the thermally extensible fiber, for example, those described in Japanese Patent Application No. 2005-353780 can be used.

  Since the above-described heat-extensible composite fiber itself can be heat-sealed, by using this fiber, it is possible to easily form a thermal bond nonwoven fabric, that is, a nonwoven fabric in which fibers are bonded (ie, fused) by application of heat. Obtainable. The heat-extensible conjugate fiber can be stretched in the nonwoven fabric by applying heat during the production of the nonwoven fabric.

FIG. 2 is a partial cross-sectional view schematically showing an enlarged part of a cross section passing through the apex of the convex portion 4 of the absorbent article shown in FIG. The convex part 4 has a vertex, and the sectional shape of the convex part passing through the vertex is an arch shape. The absorbent body 3 has an arch-shaped cross-section by a region deformed into an arch shape included in the back surface region so as to align with the concave-convex deformation of the topsheet 1, and has a convex top portion 3a facing the skin contact surface, A side wall portion 3b of the convex portion and a concave bottom surface 3c are formed.
The top sheet 1 is arranged in a state of being bonded to the absorber 3 at any position of the convex top portion 3a, the side wall portion 3b of the convex portion, and the concave bottom surface 3c. In 3a, the surface sheet 1 is pressed, and the thickness of the bonded surface sheet 1 is gradually increased from the side wall 3b to the bottom 3c of the convex portion of the absorber 3. Depending on the conditions, only a part of the convex top portion 3a, the side wall portion 3b of the convex portion, and the bottom surface 3c of the concave portion is joined at the bottom surface of the concave portion. Flexibility becomes better.

  In the present invention, unless otherwise specified, the “convex apex portion” refers to a region around the top of the convex portion, and generally refers to a portion in the region 11 in FIG. The “side wall portion of the convex portion” refers to a region that forms a side surface or an inclined surface of a convex portion, and generally refers to a portion in the region 12 in FIG. The “recess bottom surface” means a valley sandwiched between a plurality of convex portions, and in FIG. In addition, the “convex region” is a region where the convex apex portion is a region where the side wall portions of the convex portions surrounding the convex top portion are combined. In FIG. The region 13 is also referred to as a “concave region”.

  Moreover, as shown in the figure, the back surface region 3d of the absorbent body 3 includes a region that is deformed in an arch shape in the longitudinal section, and the absorbent body 3 is denser in fibers in the convex top portion 3a than in the concave bottom surface 3c. That is, it is preferable that the thickness is reduced by compression. The thickness of the bottom 3c is preferably 0.6 to 9 mm, and more preferably 0.6 to 8 mm. 0.1-5 mm is preferable and, as for the thickness of the convex top part 3a, 0.2-4 mm is more preferable.

Moreover, as for the surface sheet 1, it is preferable that the area ratio of the recessed area | region 13 is smaller than the convex area | region 14 seen from the skin contact surface side. Here, the area ratio of the topsheet 1 can be measured by obtaining the area of the concave region 13 within a range of 60 mm length × 40 mm width from an enlarged photograph in plan view. The area of the recess 13 can be obtained by an image analysis system. Light source [Sunlight SL-230K2; manufactured by LPL Co., Ltd.], stand [Copy stand CS-5; manufactured by LPL Co., Ltd.], lens [24 mm / F2.8D Nikkor lens], CCD camera [(HV-37 Connection with lens by F mount) and a video board [Spectra 3200; manufactured by Canopus Co., Ltd.] to capture the image of the uneven portion. The portion of the recessed area of the captured image is binarized by image analysis software new cube (ver. => 4.20) manufactured by NEXUS, and the area of the binarized portion is obtained.
55-90% is preferable and, as for the area ratio of the surface sheet 1 of the convex area | region 14, 55-70% is more preferable. Further, the area ratio of the recessed region 13 is preferably 10 to 45%, more preferably 20 to 45%.

On the other hand, as described above, in the absorbent sheet, in addition to the convex area 14 viewed from the skin contact surface side, the area ratio of the concave area 13 is smaller than the convex area 14 viewed from the back sheet side. It is preferable from the point of the softness | flexibility of an absorber that the area ratio of a recessed area is smaller. Since the recessed part in an absorber hits the convex part of a surface sheet, if the surface sheet and the absorber are formed as mentioned above, it can be judged that compression of an absorber is made moderately.
55-90% is preferable and, as for the area ratio of the convex area | region 14 seen from the back surface sheet side in an absorber, 55-70% is more preferable. Further, the area ratio of the recessed region 13 is preferably 10 to 45%, more preferably 20 to 45%.

In the present invention, the surface of the top of the convex portion 4 that contacts the skin of the wearer is a dense portion with a thin nonwoven fabric thickness, and has a concave portion that is macro deeper than the top portion, and the nonwoven fabric thickness of the concave portion is thick. By using a rough portion, liquid such as menstrual blood that has come out can be quickly captured by the top sheet 1 of the concave portion, transferred to the absorbent body 3, and instantly separated from the body, and stickiness can be reduced. .
At this time, by using a pulp fiber having a higher absorption holding power than the top sheet 1 as the absorbent body 3, the liquid that has passed through the top sheet 1 can be taken in and reliably held without returning.

In addition, since the portion having a high pulp density of the absorbent body 3 is the top, the liquid absorption action can be increased synergistically, the liquid can be transferred into the absorbent body more quickly, and the shape is stabilized. .
Moreover, since the surface sheet 1 can increase the area ratio between the convex area with high density and the skin having a large force to draw liquid by making the area ratio of the concave area 13 smaller than the convex area 14, The liquid on the side can be absorbed and transferred to the absorber 3.

  Next, the entire structure of the absorbent article of the present invention will be described with reference to FIG. 3 schematically showing an embodiment thereof (a perspective view in which this is enlarged to show two sides in section corresponds to FIG. 1). ). However, the absorbent article of the present invention is not construed as being limited to this form. In the absorbent article 20 of the present embodiment, a composite material 21 composed of a top sheet and an absorber is joined to the liquid-impermeable sheet 2 by a joining means using a hot-melt adhesive. Further, in the peripheral portion of the absorbent article 20, only the top sheet 1 is extended and bonded by the liquid impermeable sheet 2 by a bonding means such as heat sealing or ultrasonic sealing, or by using a hot melt adhesive in combination. ing. Moreover, the leak-proof groove 22 is formed so that the excretion part opposing part (vertical and horizontal center part) which opposes a wearer's excretion part may be enclosed. A large number of convex portions 4 are continuously provided on the surface in contact with the wearer.

Below, the preferable aspect of the manufacturing method of the absorbent article of this invention is demonstrated. However, the present invention is not construed as being limited thereby.
First, the nonwoven fabric sheet 21 which becomes a surface sheet is pulled out from a raw fabric roll. The main component is pulled out in the direction of the absorbent body 22 formed of pulp fibers obtained by defibrating natural fibers from another raw roll. And the biting method which consists of the convex part 33 and the recessed part 34 which were piled up the nonwoven fabric sheet 31 and the absorber 32 which were pulled out, and was uneven | corrugated-molded by the predetermined pattern as it is shown by the typical sectional drawing of FIG. The nonwoven fabric sheet 31 and the absorbent body 32 are partially crimped at the convex portion 33 of the embossing roll. At this time, the non-woven sheet 31 and the absorbent body 32 are partially crimped so that the pin-shaped member of the convex portion 33 pushes down the absorbent body 32 from above. The portion of the nonwoven fabric sheet 31 that is pressure-bonded to the absorbent body 32 by the embossing process is pressed and thinned to become a dense state. On the other hand, the portion of the nonwoven fabric sheet 21 that is not pushed by the pin-like member of the convex portion 23 can maintain a sparse space.

Next, the nonwoven fabric sheet 21 is heat treated.
In the composite sheet of the present invention, by performing the heat treatment, the compression of the composite material concave portion can be released to make it bulky and soft. At this time, if the heat-extensible fiber is used for the nonwoven fabric sheet (for example, the one disclosed in Japanese Patent Application No. 2005-353780), the bulkiness by heat treatment can be obtained more effectively. In this way, an excellent liquid absorbing function and a soft soft feeling can be given to the composite material (absorbing sheet) used for the absorbent article. In addition, the nonwoven fabric sheet | seat 21 densified in the film form as mentioned above does not expand | extend by such heat processing, but the density remains high.

  The absorbent article of the present invention is manufactured by laminating a liquid-impermeable sheet on a composite material obtained by integrating the nonwoven fabric sheet and the absorbent body obtained by the above method. At this time, the liquid-impermeable sheet is laminated on the side of the absorbent body not attached with the nonwoven fabric sheet. Moreover, the heat treatment of the nonwoven fabric sheet is not limited to before the surface sheet is laminated, and may be performed after the surface sheet is laminated, or may be performed a plurality of times. Although the specific method of heat processing is not specifically limited, For example, the method of supplying heat to the whole nonwoven fabric sheet by spraying hot air etc. is preferable.

It is a perspective view shown by the principal part cross section of preferable one Embodiment of the absorbent article of this invention. It is the fragmentary sectional view which expanded the absorber in FIG. 1 partially, and was shown typically. It is the top view which showed typically one preferable embodiment of the absorbent article of this invention. It is process explanatory drawing which showed typically the one part process of the manufacturing method of the absorbent article of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top sheet 1a Top of convex part of surface sheet 2 Liquid impervious sheet 3 Absorber 3a Convex top part of absorber 3b Side wall part of convex part of absorber 3c Concave bottom surface of absorbent 3d Back side of absorbent body 4 Convex part 11 Region of convex top portion 12 Region of convex portion side wall portion 13 Concavity region 14 Convex region 20 Absorbent article 21 Composite material 22 Leak-proof groove 31 Non-woven fabric sheet 32 Absorbent body 33 Convex portion of embossing roll of biting method 34 Biting type of biting method Embossing roll recess

Claims (3)

In an absorbent article in which an absorbent is disposed between the two sheets, a liquid-permeable surface sheet on the skin contact surface side, a back sheet on the non-skin contact surface side,
The top sheet is made of nonwoven fabric,
The absorber contains pulp fiber as a main component,
The top sheet and the absorber are overlaid, and the top sheet and the absorber that are overlaid are both formed with a convex part and a concave part that protrude from the back sheet side to the skin contact surface side,
The convex portion has a vertex, and the convex sectional shape passing through the vertex is an arch shape,
The said surface sheet and an absorber are joined to the absorber in the said convex-part vertex and convex-part side wall part, Furthermore, the thickness of a surface sheet becomes high gradually from the side wall part of the said convex part to a recessed part bottom face. .   2. The absorbent article according to claim 1, wherein the density of the absorbent body from the top of the convex portion to the bottom surface of the concave portion is such that the fibers at the top of the convex portion are denser than the bottom surface of the concave portion.   The absorbent article according to claim 1 or 2, wherein the liquid-permeable surface sheet is a nonwoven fabric composed of fibers that are elongated by heat.

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