JP4851169B2 - Absorbent article and manufacturing method thereof - Google Patents

Description

  The present invention is an absorbent article using a surface sheet that is rich in three-dimensionality, has high cushioning properties, eliminates skin troubles by reducing the contact area with the skin, and has excellent shape retention of uneven embossing And a manufacturing method thereof.

  Conventionally, as a surface material of an absorbent article, an appropriate embossing pattern has been given according to various purposes such as reducing the contact area with the skin to suppress the moist feeling, or giving the texture and enhancing the touch. Things are offered to the market. As this kind of thing, the following patent documents 1-5 etc. can be mentioned, for example.

  In the following Patent Document 1, a number of flanges and grooves are alternately arranged so as not to have a flat surface, the flanges are curved in a convex shape, and the groove is curved in a concave shape. Discloses an absorbent article using a nonwoven fabric having a large number of apertures arranged at intervals as a surface sheet.

  Further, in Patent Document 2 below, it is formed of a top portion and both side wall portions that are connected to both sides of the top portion and bend to the back surface side of the top sheet, and has a U-shaped section in a downward direction and is spaced apart from each other and extends in the vertical direction. A plurality of first ribs and a plurality of second ribs that have top portions and are spaced apart from each other and connected between both side wall portions of the first ribs, and the first ribs and the second ribs provide openings. A surface sheet is disclosed in which the top of the second rib is formed lower than the top of the first rib.

  In the following Patent Document 3, a large number of fusing lines composed of a large number of fusing points recessed from the surface sheet are defined, and the fusing lines extend obliquely with respect to the longitudinal axis of the absorbent article to form lattice-shaped concave stripes. There is disclosed an absorbent article in which a groove is formed and a plurality of the fusion points exist between the intersections of the fusion lines to form a lattice.

  In the following Patent Document 4, a plastic sheet having thermoplasticity and having a sheet surface provided with a melt pattern (emboss pattern), the melt pattern being formed under the elongation condition of the plastic sheet. Virtual lines in the substantially extending direction connecting the regions that are not continuous are given in a zigzag or rhombus pattern so as to form a concavo-convex ridge corresponding to the melt pattern arrangement on the plastic sheet surface. A plastic sheet is disclosed.

In the following Patent Document 5, after the fiber aggregates constituting the first and second fiber layers are laminated, an embossed surface (such as a peripheral surface of an embossing roll) on which a large number of pins are regularly arranged is designated as the first fiber. In the longitudinal direction and the lateral direction of the sheet, the constituent fibers of the first fiber layer and the second fiber layer are melted and heat-sealed at the portion hot-pressed to each pin by being pressed against the layer side. A surface sheet having a number of discontinuous ridges, a sheet thickness of 0.5 to 10 mm under 0.5 cN / cm ² pressure, and a shortest distance between adjacent ridges of 0.5 to 15 mm An absorptive article using is disclosed.
JP-A-8-302555 Japanese Utility Model Publication No. 10-112 JP-A-7-328060 JP 2002-160293 A JP 2003-126147 A

  However, in the case of the surface sheet described in Patent Document 1, a three-dimensional effect is surely displayed on the sheet surface by alternately arranging the ridges and the groove portions. It has a large contact area with the skin and cannot effectively prevent skin troubles such as rubbing, fogging and itching, and can eliminate the sticky feeling during blood drainage. Absent. In addition, the undulating process using the ridges and grooves on the nonwoven fabric is not sufficient in shape retention, and there is a problem in that the unevenness of the undulating process gradually decreases as the pressure is sustained while sitting or sleeping. It was.

  Moreover, in the case of the surface sheet of the said patent document 2, a 1st rib will contact skin linearly, there are many contact areas with skin, and skin troubles, such as abrasion, a blurring, and an itching, are effective. It cannot be prevented, and the sticky feeling at the time of bleeding cannot be resolved. Moreover, since the sheet structure consisting of the first rib and the second rib forms a special structure and the manufacturing process becomes complicated, it has not been put into practice.

  Furthermore, in the case of the absorbent article of Patent Document 3, the surface sheet surface is merely functionally given an emboss of a specific shape, and cannot give a high unevenness or a soft texture. .

  In the case of the plastic sheet described in the above-mentioned Patent Document 4, although it is possible to overcome the cold appearance and feel produced from the smooth plastic sheet surface, the texture of the entire sheet surface due to random wrinkles is a handkerchief before ironing It has a cloth-like appearance that is close to the above, and is somewhat poor in stereoscopic effect.

  Since the surface sheet described in Patent Document 5 has a large number of raised portions protruding from the skin surface, the contact area with the skin can be minimized and the cushioning property is also excellent. However, since the fiber portion corresponding to the concave portion is heat-sealed by pressure welding to increase the density by embossing from the surface side, the discharged menstrual blood and the like is absorbed into the concave portion by capillary action and falls out to the absorber side. It becomes difficult. Therefore, when the amount of menstrual blood is large, a sticky feeling can be felt by menstrual blood retained on the top sheet. In addition, the fiber portion of the bulge can secure a bulge amount in a dry state, but when it gets wet, the fiber is naturally compressed (deflated state), the bulge amount is reduced, and the cushioning property is extremely lowered. There were problems such as insufficient shape retention of unevenness.

  Therefore, the object of the present invention is rich in three-dimensionality, has a high cushioning property, minimizes the contact area with the skin, effectively prevents skin troubles such as rubbing, fogging and itching, and improves the touch feeling, and Disclosed is an absorbent article that can maintain a concavo-convex shape not only in a dry state but also at the time of humor absorption, and a method for producing the same, by eliminating the sticky feeling during humor absorption and further enhancing the shape retention of the concavo-convex embossment. There is.

In order to solve the above-mentioned problem, the present invention according to claim 1 is characterized in that an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and the hydrophilic sheet is disposed between the top sheet and the absorbent body. In the absorbent article intervening the second non-woven sheet,
The surface sheet is a two-layered sheet comprising a nonwoven fabric layer constituting a skin contact surface layer and a plastic film layer laminated on the non-skin contact surface side of the nonwoven fabric layer, and the plastic film The layer is composed of a material having a lower melting point than the nonwoven fabric layer,
In the state where the second nonwoven fabric sheet composed of a lower melting point material than the nonwoven fabric layer is bonded to the back surface side of the topsheet, the melting point of the plastic film layer and the second nonwoven fabric sheet is not less than the melting point of the nonwoven fabric layer. under heating conditions, the composite sheet comprising the topsheet and the second nonwoven sheet, made from a number of ridges projecting outwardly, and facilities an uneven embossing recesses interval is in the range of 3 to 7 mm, the plastic film layer and is deformed in a semi-molten or molten state nonwoven sheet by heating, with uneven curved shape is so as to be shape-retaining by said embossing process, Ri Oh subjected to numerous apertures process,
The uneven embossing uses a convex embossing roll in which a large number of convex portions are arranged and a concave embossing roll in which a large number of concave portions are formed corresponding to the convex portions. Absorption characterized by being imparted by meshing the convex part and the concave part by passing a composite sheet comprising the top sheet and the second nonwoven sheet between the roll and the concave embossing roll. A sex article is provided.

  In this invention of the said Claim 1, a surface sheet is 2 layers which consist of the nonwoven fabric layer which comprises a skin contact surface layer, and the plastic film layer laminated | stacked on the non-skin contact surface side of this nonwoven fabric layer. A second nonwoven fabric constituted by a multilayer sheet, wherein the plastic film layer uses a material having a lower melting point than the nonwoven fabric layer, and is formed on the back side of the topsheet using a material having a lower melting point than the nonwoven fabric layer. In a state where the sheets are bonded together, a large number of protrusions projecting outwards to the composite sheet composed of the top sheet and the second nonwoven sheet under heating conditions not less than the melting point of the plastic film layer and the second nonwoven sheet and less than the melting point of the nonwoven layer. The embossing of the uneven shape which consists of a protruding part is given.

  Therefore, the embossing formed on the top sheet is an uneven embossing made up of a number of protruding parts protruding outward, thereby minimizing the contact area with the skin and causing skin problems such as rubbing, fogging and itching. Can be effectively prevented, the feeling of touch is improved, and the feeling of stickiness upon absorption of body fluid can be eliminated.

  In addition, in the embossing treatment, the plastic film layer and the second non-woven sheet are deformed in a semi-molten or molten state by heating by being performed under a heating condition that is equal to or higher than the melting point of the plastic film layer and the second non-woven sheet. Therefore, after embossing treatment, the concave and convex curve shape will be firmly held, so that the concave and convex shape is maintained even in the wet state as well as the cushioning property in the dry state Become. On the other hand, since the nonwoven fabric layer constituting the surface layer is less affected by heat during embossing, the texture can be maintained.

  Furthermore, when the hydrophilic second nonwoven sheet and the top sheet are stacked separately, a space is formed between the second nonwoven sheet and the top sheet (particularly at the embossed convex portion). By superimposing the sheet on the surface sheet and embossing it together, the body fluid present in the surface sheet can be quickly absorbed by the second nonwoven fabric sheet and absorbed by the absorbent body, eliminating the surface residue of body fluid. it can. Moreover, a higher cushioning property can be given by the second nonwoven fabric sheet.

In this invention, the recessed part space | interval of the uneven embossing formed in the said surface sheet shall be the range of 3-7 mm. As shown in the examples described later, by providing an arrangement pattern of raised portions with the interval between the recesses in the range of 3 to 7 mm, it is rich in three-dimensional effect and can have high cushioning properties. As a result, a feeling of touch can be improved and a sticky feeling at the time of body fluid absorption can be eliminated.

  According to a second aspect of the present invention, the material of the nonwoven fabric layer constituting the surface sheet is polypropylene, the material of the plastic film layer is polyethylene, and the material of the second nonwoven fabric sheet is polyethylene or polyethylene / polypropylene. An absorbent article according to 1 is provided.

  In the present invention described in claim 2, the material of the non-woven fabric layer that specifically constitutes the surface sheet is polypropylene, the material of the plastic film layer is polyethylene, and the material of the second non-woven fabric sheet is polyethylene or polyethylene / polypropylene (core Sheath type composite fiber). Here, the melting point of the polypropylene is 165 ° C., and the melting point of the polyethylene is 115 ° C. at a low density and 137 ° C. at a high density.

  As this invention which concerns on Claim 3, the said 2nd nonwoven fabric sheet and an absorber are joined by the recessed lower surface of the said 2nd nonwoven fabric sheet, The absorbent article in any one of Claim 1, 2 is provided.

  In the invention according to claim 3, the second nonwoven fabric sheet and the absorbent body are joined to each other by a hot melt adhesive or the like on the lower surface of the concave portion of the second nonwoven fabric sheet, so that menstrual blood or the like can be rapidly removed from the concave portion of the second nonwoven fabric sheet. It becomes possible to penetrate and absorb the absorbent body.

The absorbent article according to any one of claims 1 to 3 , wherein, as the present invention according to claim 4 , the convex width of the concavo-convex emboss formed on the composite sheet comprising the top sheet and the second nonwoven fabric sheet is 5 mm or less. Provided.

In the invention described in claim 4 , the convex width of the concavo-convex embossment is 5 mm or less, so that the area in contact with the skin is reduced. As a result, the feeling of touch is improved and the sticky feeling when absorbing body fluids. It can be lost.

As the present invention according to claim 5, absorbent article according to the composite sheet consisting of said topsheet and second nonwoven sheet, according to claim 1-4 or a number of apertures that are formed in a range including at least the recess Is provided.

In the present invention according to claim 5 , in the surface sheet, a large number of apertures are formed in a range including at least the concave portion, and the body fluid that has flowed into the concave portion through the raised portion of the surface sheet is retained. Can be quickly absorbed into the absorbent body.

As the present invention according to claim 6 , there is provided the absorbent article according to any one of claims 1 to 5 , wherein the second nonwoven fabric sheet is an air-through nonwoven fabric.

In this invention of the said Claim 6 , an air through nonwoven fabric is used as said 2nd nonwoven fabric sheet. Due to the bulkiness of the air-through nonwoven fabric, a high cushioning property can be imparted to the surface sheet.

As the present invention according to claim 7, an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and a hydrophilic second nonwoven fabric sheet is interposed between the top sheet and the absorber. In the manufacturing method for the absorbent article,
The top sheet is a two-layered sheet composed of at least a nonwoven fabric layer constituting a skin contact surface layer and a plastic film layer laminated on the non-skin contact surface side of the nonwoven fabric layer, and the plastic The film layer is composed of a lower melting point material than the nonwoven fabric layer,
After pasting a second nonwoven fabric sheet composed of a lower melting point material than the nonwoven fabric layer on the back surface side of the topsheet, a convex embossing roll in which a plurality of convex portions are arranged, and the convex portion Correspondingly, a composite sheet composed of the top sheet and the second nonwoven fabric sheet is passed between the concave embossing roll formed with a number of concave portions, and the nonwoven fabric layer has a melting point equal to or higher than the melting point of the plastic film layer and the second nonwoven fabric sheet. The plastic film layer is formed by subjecting the composite sheet to concavo-convex embossing having a number of ridges protruding outward and having a recess interval of 3 to 7 mm under heating conditions lower than the melting point. and non-woven sheet is deformed in a semi-molten or molten state by heating, there uneven curved shape by the embossing process so as to be shape-retaining Both manufacturing method for absorbent articles, characterized in that applying a plurality of apertures process is provided.

As the present invention according to claim 8 , there is provided a convex embossing roll and a concave embossing roll in which the depth of the concave portion of the concave embossing roll is formed larger than the height of the convex portion of the convex embossing roll. The manufacturing method of the absorbent article of Claim 7 to be used is provided.

  As described above in detail, according to the present invention, the three-dimensional effect is high, the cushioning property is high, the contact area with the skin is minimized, and skin troubles such as rubbing, fogging and itching are effectively prevented and the feeling of touch is improved. And the stickiness when absorbing bodily fluids can be eliminated. In addition, since the plastic film layer and the second nonwoven fabric sheet are deformed in a semi-molten or molten state, the shape retention of the uneven embossing can be improved while maintaining the texture of the surface nonwoven fabric layer, and the body fluid can be used not only in the dry state. The uneven shape can be maintained even during absorption.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially broken perspective view of a thin sanitary napkin 1 according to the present invention.

[Structure of absorbent article 1]
The sanitary napkin 1 is mainly used for applications such as panty liners, sanitary napkins, cage sheets, incontinence pads, and the like. For example, as shown in FIG. The absorbent body 4 or the absorbent body 4 surrounded by the crepe paper 5 is interposed between the liquid permeable top sheet 3 (hereinafter, simply referred to as a top sheet), as shown in FIG. A hydrophilic second sheet 6 is arranged between the sheet 3 and the absorber 4. Around the absorber 4, the liquid-impermeable back sheet 2 and the top sheet 3 are joined by an adhesive means such as a hot melt adhesive.

  The liquid-impervious back sheet 2 is made of a sheet material having at least water-impervious properties such as polyethylene and polypropylene, but in addition to this, a non-woven sheet after securing a substantially liquid-impervious property through a waterproof film. (In this case, a liquid-impervious back sheet is composed of the waterproof film and the nonwoven fabric). In recent years, those having moisture permeability tend to be suitably used from the viewpoint of preventing stuffiness. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used.

  As the surface sheet 3, a multilayer sheet having at least a nonwoven fabric layer constituting a skin contact surface layer and a plastic film layer laminated on the non-skin contact surface side from the nonwoven fabric layer is used, and outwardly. An uneven embossing made of a large number of protruding ridges 7, 7... Is applied, and a material subjected to a large number of opening treatments is used. The surface sheet 3 will be described in more detail later.

  The absorbent body 4 interposed between the liquid-impermeable back sheet 2 and the top sheet 3 is, for example, a mixture of a highly water-absorbent resin in pulp, or a mixture of chemical fibers in the pulp and a high water absorption. A material mixed with a conductive resin is used. As shown in the figure, it is desirable that the absorbent body 4 is surrounded by crepe paper 5 in order to maintain its shape and quickly diffuse menstrual blood and prevent reverse return of menstrual blood once absorbed. Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as molten pulp, and artificial cellulose fibers such as rayon and acetate. Softwood pulp having a longer fiber length than hardwood pulp functions and It is preferably used in terms of price.

  Examples of the superabsorbent resin include cross-linked polyacrylate, self-crosslinked polyacrylate, saponified acrylate-vinyl acetate copolymer cross-linked, isobutylene / maleic anhydride copolymer cross-linked, Examples include cross-linked polysulfonates, and partially cross-linked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. In the production process of the highly water-absorbent resin having the water absorption performance, the water absorption force and the water absorption speed can be adjusted by adjusting the crosslinking density and the crosslinking density gradient. The content of the superabsorbent resin is preferably 10 to 60%. When the content of the superabsorbent resin is less than 10%, sufficient absorbability cannot be provided, and when it exceeds 60%, the entanglement between the pulp fibers disappears, the sheet strength decreases, and tears, cracks, etc. Is likely to occur.

  The hydrophilic second nonwoven fabric sheet 6 disposed between the liquid-permeable surface sheet 3 and the absorbent body 4 only needs to be hydrophilic to the body fluid. Specifically, by using recycled fibers such as rayon and cupra, natural fibers such as cotton, the material itself has hydrophilicity, or synthesis of olefins such as polyethylene or polypropylene, polyesters, polyamides, etc. The fiber which surface-treated with the hydrophilizing agent and provided the hydrophilic property can be used. As will be described later, the second nonwoven fabric sheet 6 is bonded to the back surface side of the top sheet 3 by hot melt or heat fusion (embossing), and is embossed together with the top sheet 3 with both sheets in a laminated state. The

  It is desirable that the second nonwoven fabric sheet 6 and the absorbent body 4 are joined to each other on the lower surface of the concave portion of the second nonwoven fabric sheet 6 with a hot melt adhesive or the like. By joining the lower surface of the concave portion of the second nonwoven fabric sheet 6 and the absorbent body 4, menstrual blood or the like can quickly penetrate into the absorbent body 4 from the concave portion of the second nonwoven fabric sheet 6 and be absorbed.

[Structure of surface sheet 3 and second non-woven sheet 6]
As shown in FIG. 2, the surface sheet 3 comprises a nonwoven fabric layer 3A constituting a skin contact surface layer and a plastic film layer 3B laminated on the non-skin contact surface side of the nonwoven fabric layer 3A. The plastic film layer is made of a material having a lower melting point than the nonwoven fabric layer, and has an uneven embossing process composed of a plurality of protruding portions 7, 7. In addition, a liquid-permeable sheet that has been subjected to a number of opening treatments is used.

  Examples of the material fibers constituting the nonwoven fabric layer 3A include synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon and cupra, and natural fibers such as cotton. In addition, a nonwoven fabric obtained by an appropriate processing method such as an air-through method, a spunlace method, a spunbond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the air-through method and the thermal bond method are excellent in terms of being bulky and soft. The non-woven fiber may be either a long fiber or a short fiber, but preferably a short fiber is used in order to give a towel texture. In order to facilitate the embossing treatment, it is preferable to use an olefin fiber such as polyethylene or polypropylene having a relatively low melting point. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can be suitably used.

  On the other hand, as the material of the plastic film layer 3B, for example, olefin resins such as polyethylene and polypropylene, polyamide resins such as polyester and nylon, ethylene-vinyl acetate copolymer (EVA), and the like can be preferably used. .

  In this surface sheet 3, each material is selected from the nonwoven fabric material group and the plastic film material group so that the material of the plastic film layer 3B has a relatively lower melting point than the material of the nonwoven fabric layer 3A.

  On the other hand, as the second nonwoven fabric sheet 6, a material having a lower melting point than that of the nonwoven fabric layer 3A is used. Preferably, an air-through nonwoven fabric is used in order to increase the bulk.

  In the embossing process, as shown in FIG. 2, the second nonwoven fabric sheet 6 made of a material having a lower melting point than the nonwoven fabric layer 3A is hot-melted or heat-sealed on the back surface side of the topsheet 3. In the state of being bonded together, under the heating conditions not less than the melting point of the plastic film layer 3B and the second nonwoven fabric sheet 6 and less than the melting point of the nonwoven fabric layer 3A, as shown in FIG. A concavo-convex embossing process including a large number of protruding ridges 7, 7... Is performed, and a large number of opening processes (not shown) are performed.

  As an example of the most common material combination, the material of the nonwoven fabric layer 3A is polypropylene, the material of the plastic film layer 3B is polyethylene, and the second nonwoven fabric sheet 6 is polyethylene or polyethylene / polypropyne (core-sheath type composite fiber) Examples of the combinations can be given. Since the melting point of the polypropylene is 165 ° C. and the melting point of the polyethylene is 115 ° C. at low density and 137 ° C. at high density, the roll heating temperature during embossing exceeds 115 ° C. (137 ° C.) and less than 165 ° C. By setting the temperature, the plastic film layer 3B and the second nonwoven fabric sheet 6 are deformed in a semi-molten or molten state, so that the uneven curve shape is firmly retained after the embossing treatment, Not only the cushioning property in the dry state but also the uneven shape is maintained even in the wet state. In addition, since the raised portions 7, 7... That come into contact with the skin are the nonwoven fabric layer 3A, they are not affected by the embossing heat, so that the feel of the material can be maintained. If the heating temperature exceeds the melting point of the non-woven fabric layer 3A, the entire surface of the non-woven fabric layer 3A constituting the surface layer is plasticized and hardened, so that the surface texture and feel of the surface are impaired. .

The basis weight of the nonwoven fabric layer 3A constituting the surface sheet 3 is preferably 20 g / m ² or less, and the basis weight of the plastic film layer 3B is preferably 15 g / m ² or more. About the said nonwoven fabric layer 3A of the surface layer, a sticky feeling can be eliminated by setting the basis weight to 20 g / m ² or less and reducing the amount of retained menstrual blood. It is desirable that the basis weight of the second nonwoven fabric sheet 6 is 15 g / m ² or more to increase menstrual blood retraction and to give the required hardness by plasticization.

  In order to emboss the surface sheet 3, as shown in FIG. 4, the convex embossing roll 10 in which a large number of convex portions 10a, 10a... Are arranged, and as shown in FIG. .. Are formed between the convex embossing roll 10 and the concave embossing roll 11. The top sheet 3 and the second nonwoven fabric are used between the convex embossing roll 10 and the concave embossing roll 11. By passing the composite sheet made of the sheet 6, it can be applied by meshing the convex portion 10a and the concave portion 11a. Embossing by meshing the convex part and the concave part by a convex embossing roll in which a large number of convex parts are arranged and a concave embossing roll in which a number of concave parts are formed corresponding to the convex part. Since it is not necessary to create an extreme fiber density difference between the high-density region of the fiber and the low-density region with respect to the surface sheet, the body fluid is not retained in the high-density region of the fiber. The sticky feeling at the time of absorption will be eliminated.

  In this case, the height h1 of the convex portion 10a of the convex embossing roll 10 is preferably about 1.5 to 2.5 mm, and the depth h2 of the concave portion 11a of the concave embossing roll 11 is 1. It is desirable to be about 7 to 2.7 mm. Further, the depth of the concave portion 11a is formed to be larger than the height of the convex portion 10a, and as shown in FIG. 6, the convex portion 10a does not contact the concave portion 11a in an engaged state, It is desirable that a predetermined gap, specifically 0.1 to 0.5 mm, preferably 0.2 to 0.4 mm, be formed throughout. Embossing can be provided without forming a high-density region of fibers in the nonwoven fabric layer of the topsheet by providing embossing while eliminating a portion where the concave portion 11a and the convex portion 10a are in contact with each other.

  The recess spacing P (see FIG. 5) of the concavo-convex emboss formed on the top sheet 3 is desirably set in the range of 3 to 7 mm, preferably 3 to 6 mm. When the interval P between the concave portions is less than 3 mm, the raised portions 7 and 7 are too close to each other. When the recess interval P exceeds 7 mm, the interval is too wide to obtain desired cushioning properties. Moreover, since a recessed part comes in contact with skin, while a feeling of touch worsens, the sticky feeling at the time of bodily fluid absorption cannot be eliminated. Also, the convex width b (see FIG. 5) of the concavo-convex embossment is 5 mm or less, and by reducing the area in contact with the skin, the touch feeling is improved and the sticky feeling when absorbing body fluids is eliminated. Is desirable.

Meanwhile, openings are formed on the surface sheet 3, ² opening area per the 0.35～0.60Mm, preferably a 0.47～0.54Mm ^2, the hole area ratio from 10 to 19% Preferably, it forms in the ratio of 11-14%. When the opening area is less than 0.35 mm ² , the opening area is too small and body fluid stays in the opening wall. In addition, when the aperture area exceeds 0.60 mm ² , body fluid reverses through the aperture, which is not preferable. On the other hand, when the open area ratio is less than 10%, the open area ratio is too small and the body fluid discharged to the surface cannot be quickly transmitted. On the other hand, if it exceeds 19%, the return of body fluid occurs, which is not preferable.

  It is desirable that the opening be provided only in the recessed portion excluding the raised portions 7 and 7 or formed in a range including the recessed portion. By forming the opening in a range including at least the recess, the body fluid that has flowed into the recess through the raised portions 7, 7... Of the topsheet 3 can be quickly absorbed to the absorber 4.

  In order to form the openings, the plastic film layer 3B is softened to near the softening temperature and is positioned on the upper surface of the support having a large number of openings, and is sucked from below the support. For example, a method of forming a hole by pressurizing with air pressure from the upper surface of the wire, a method of piercing a heating needle, or the like can be employed. In addition, the opening process may be performed after the nonwoven fabric layer 3A and the plastic film layer 3B are laminated, and the openings may be formed in all the laminated layers, but at least for the plastic film layer 3B. It only has to be made. In the opening process in this case, after the opening is formed in the plastic film layer 3B, the nonwoven fabric layer 3A is laminated.

(1) Cushioning property test due to difference in recess-side spacing P In this example, the difference in cushioning property due to the difference in recess spacing P was examined. In the test, the height h1 of the convex portion 10a of the convex embossing roll 10 is fixed to 1.8 mm, the depth h2 of the concave portion 11a of the concave embossing roll 11 is fixed to 1.8 mm, and the concave interval P is set to 2. While making what was changed in the range of 5 to 10 mm, the WC value (compression energy) by a KES compression tester was tested as an index value of the cushioning property for each specimen without embossing.

The KES compression tester (manufactured by Kato Tech Co., Ltd.) is a tester for simulating the sensation of touching an object with a human fingertip, and measures compression energy, compression hardness, compression recovery, etc. Can do. As shown in FIG. 7 (A), the speed of the sample was 0.1 cm / sec, the compression area: 2 cm ² , SENS: 2 (force gauge 200 g / 10 v), DEF sensitivity: 5, compression load: 50 gf / Compression is performed under the condition of cm ² , and LC (compression hardness), WC (compression energy), and RC (compression recoverability) are calculated from a correlation diagram between pressure and deformation.

  The LC (compression hardness) is indicated by [a + b area] / [ΔABC area] in the correlation diagram between the pressure and the deformation amount shown in FIG. It becomes evaluation that is hard. The WC (compression energy) is represented by [a + b area], and the larger the value, the easier it is to compress. The last RC (compression recoverability) is indicated by [area b] / [area a + b], and the evaluation is such that the closer the value is to 100%, the recoverability is. Among these test items, WC (compression energy) is preferably used as an index for the softness (cushioning property) determined by sensory evaluation.

  The test results are shown in Table 1 below and shown in FIG.

  As shown in FIG. 8, in the graph in which the horizontal axis is the interval between the concave portions and the vertical axis is the compression work amount, it becomes a convex curve protruding upward as a whole, and the concave portion interval P is set in the range of 3 to 7 mm Has been found to be particularly cushioning.

It is a partially broken perspective view of the absorbent article 1 according to the present invention. It is a figure which shows the base-material cross-section structure (before embossing) of the liquid-permeable surface sheet 3 and the 2nd nonwoven fabric sheet 6. FIG. It is a figure which shows the base-material cross-section structure (after embossing) of the liquid-permeable surface sheet 3 and the second nonwoven fabric sheet 6. The convex side embossing roll 10 is shown, (A) is a top view, (B) is the BB line arrow directional view. The concave embossing roll 11 is shown, (A) is a plan view, and (B) is a BB line arrow view. It is a figure which shows the meshing state of the convex side embossing roll 10 and the concave side embossing roll 11. FIG. (A) is a test procedure diagram using a KES compression tester, and (B) is a correlation diagram between pressure and deformation amount indicating the KES compression test result. It is a graph which shows the test result of an Example.

  DESCRIPTION OF SYMBOLS 1 ... Absorbent article (sanitary napkin), 2 ... Impervious back sheet, 3 ... Impervious surface sheet, 4 ... Absorber, 5 ... Crepe paper, 6 ... Second sheet, 7 ... Raised part, 10 ... Convex-side embossing roll, 10a ... Convex part, 11 ... Concave-side embossing roll, 11a ... Concave part

Claims (8)

In the absorbent article in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and a hydrophilic second nonwoven fabric sheet is interposed between the top sheet and the absorber,
The surface sheet is a two-layered sheet comprising a nonwoven fabric layer constituting a skin contact surface layer and a plastic film layer laminated on the non-skin contact surface side of the nonwoven fabric layer, and the plastic film The layer is composed of a material having a lower melting point than the nonwoven fabric layer,
In the state where the second nonwoven fabric sheet composed of a lower melting point material than the nonwoven fabric layer is bonded to the back surface side of the topsheet, the melting point of the plastic film layer and the second nonwoven fabric sheet is not less than the melting point of the nonwoven fabric layer. under heating conditions, the composite sheet comprising the topsheet and the second nonwoven sheet, made from a number of ridges projecting outwardly, and facilities an uneven embossing recesses interval is in the range of 3 to 7 mm, the plastic film layer and is deformed in a semi-molten or molten state nonwoven sheet by heating, with uneven curved shape is so as to be shape-retaining by said embossing process, Ri Oh subjected to numerous apertures process,
The uneven embossing uses a convex embossing roll in which a large number of convex portions are arranged and a concave embossing roll in which a large number of concave portions are formed corresponding to the convex portions. Absorption characterized by being imparted by meshing the convex part and the concave part by passing a composite sheet comprising the top sheet and the second nonwoven sheet between the roll and the concave embossing roll. Sex goods.   The absorbent article according to claim 1, wherein a material of the nonwoven fabric layer constituting the surface sheet is polypropylene, a material of the plastic film layer is polyethylene, and a material of the second nonwoven fabric sheet is polyethylene or polyethylene / polypropylene.   The absorbent article according to claim 1, wherein the second nonwoven fabric sheet and the absorbent body are bonded to each other at a lower surface of the concave portion of the second nonwoven fabric sheet.   The absorbent article according to any one of claims 1 to 3, wherein a convex width of the uneven emboss formed on the composite sheet comprising the top sheet and the second nonwoven sheet is 5 mm or less.   The absorbent article according to any one of claims 1 to 4, wherein in the composite sheet composed of the top sheet and the second nonwoven sheet, a large number of apertures are formed in a range including at least a recess.   The absorbent article according to claim 1, wherein the second nonwoven fabric sheet is an air-through nonwoven fabric. In the method for producing an absorbent article in which an absorbent body is interposed between the liquid-permeable surface sheet and the back sheet, and a hydrophilic second nonwoven fabric sheet is interposed between the surface sheet and the absorbent body,
The top sheet is a two-layered sheet composed of at least a nonwoven fabric layer constituting a skin contact surface layer and a plastic film layer laminated on the non-skin contact surface side of the nonwoven fabric layer, and the plastic The film layer is composed of a lower melting point material than the nonwoven fabric layer,
After pasting a second nonwoven fabric sheet composed of a lower melting point material than the nonwoven fabric layer on the back surface side of the topsheet, a convex embossing roll in which a plurality of convex portions are arranged, and the convex portion Correspondingly, a composite sheet composed of the top sheet and the second nonwoven fabric sheet is passed between the concave embossing roll formed with a number of concave portions, and the nonwoven fabric layer has a melting point equal to or higher than the melting point of the plastic film layer and the second nonwoven fabric sheet. The plastic film layer is formed by subjecting the composite sheet to concavo-convex embossing having a number of ridges protruding outward and having a recess interval of 3 to 7 mm under heating conditions lower than the melting point. and non-woven sheet is deformed in a semi-molten or molten state by heating, there uneven curved shape by the embossing process so as to be shape-retaining Both manufacturing method for absorbent articles, characterized in that applying a plurality of apertures process.   The absorptive article according to claim 7 using the convex side embossing roll and the concave side embossing roll in which the depth of said concave part of said concave side embossing roll is formed larger than the height of the convex part of said convex side embossing roll. Manufacturing method.

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