JP4369810B2 - Sanitary napkin - Google Patents

Description

The present invention also relates sweat, urine, the intended sanitary napkin down that promote the absorption of such body fluid menses.

  Absorbent articles such as sanitary napkins and disposable paper diapers usually have a structure in which an absorbent for absorbing and holding body fluid is interposed between a liquid-impermeable back sheet and a liquid-permeable top sheet. In such an absorbent article, the consumer always demands a product that is thin, light, less uncomfortable when worn, and excellent in liquid permeability.

  Since the weight, thinness, and liquid permeability of absorbent articles largely depend on the absorbent body, it is regarded as an industry effort to reduce the weight and thickness of the absorbent body and improve the high liquid permeability. ing. As shown in the following prior art documents, various techniques for improving the function of the absorber are disclosed.

  For example, JP-A-8-24289 discloses a surface material made of cotton and an absorbent material made of a hydrophilic nonwoven fabric. This absorbent material mainly comprises hollow synthetic fibers composed of fibers having an average fiber diameter of about 1 to 3 denier and having an average fiber diameter of about 4 to 8 denier in order to provide an overall elastic return to deformation. Yes. This absorbent material is intended to prevent the occurrence of twist due to the use of a surface material made of cotton by using the absorbent material containing the hollow synthetic fiber.

Japanese Patent Application Laid-Open No. 63-109859 discloses an absorbent article having an absorbent containing hydrophilic fibers and a superabsorbent polymer, in which the absorbent is provided with an acquisition band and a storage band located around the acquisition band. The acquisition zone has a lower density and lower basis weight than the storage zone. In this absorbent article, the liquid is transferred from the acquisition zone to the storage zone so that the superabsorbent polymer contained in the storage zone does not cause gel blocking.
JP-A-8-24289 Japanese Unexamined Patent Publication No. 63-109859

  However, the absorbent body constituting the absorbent article described in the above document has the following drawbacks and there is room for improvement. The absorbent body disclosed in JP-A-8-24289 has low liquid permeability because the surface material is made of cotton, and the absorbed menstrual blood tends to stay on the surface material, giving a very dirty impression to the user. There is a drawback.

  On the other hand, the absorber disclosed in JP-A-63-109859 is composed of conventionally known hydrophilic fibers and superabsorbent polymers in both the acquisition zone and the storage zone although there are differences in density and basis weight. The liquid permeability of the acquisition zone and the storage zone itself is not different from other conventional products using this type of absorbent material.

  Therefore, the main problem of the present invention is to improve the drawbacks and improvement points included in the prior art also shown in the above example, there is no sag, liquid permeability is improved, and softness is also improved. It is to provide an absorber.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In a sanitary napkin in which an absorbent for absorbing and holding bodily fluid is interposed between a liquid-impermeable back sheet and a liquid-permeable top sheet,
The absorbent body includes a toe area composed of tow 1-16 denier crimped continuous fibers in being that fiber aggregate obtained by spreading, pulp fibers, porous foam, cotton fibers, nonwoven least a And a thickness maintaining region made of an absorbent material other than tow and having a smaller work of compression (WC) than the tow region,
The thickness maintaining region has a compression work (WC) of 1.0 to 3.0 gfcm / cm ² and a density of 10 to 100 kg / m ³ .
The tow region has a compression work (WC) of 3.0 to 10.0 gfcm / cm ² and a density of 10 to 100 kg / m ³ .
The thickness maintaining region is provided so as to extend across the widthwise central portion of the absorber and both side portions thereof.
The tow region is disposed so as to extend in the longitudinal direction at the center in the width direction of the absorber,
A concave portion is provided on the side surface of the top sheet of the thickness maintaining region in the central portion in the width direction, and the tow region is provided in the concave portion so as to be exposed on the surface of the absorber .
The exposed portion of the surface of the toe region in the central portion in the width direction of the absorber protrudes toward the top sheet side than the side surface of the top sheet in the thickness maintaining region .
A sanitary napkin characterized by that.
<Invention of Claim 2>
The sanitary napkin according to claim 1, wherein the absorbent body has portions formed by folding the use surface of both sides in the width direction of the constituent material constituting the thickness maintaining region on both sides in the width direction of the absorbent body.
<Invention of Claim 3>
The said recessed part is not provided in the said thickness maintenance area | region, The said tow | toe area | region is provided in the said width direction center part so that the said thickness maintenance area | region may be penetrated from the surface to a back surface. Sanitary napkin .

<Invention of Claim 4 >
The physiology according to any one of claims 1 to 3 , wherein the tow region extends along the longitudinal direction at a central portion in the width direction of the absorbent body within a range not reaching the peripheral edge of the absorbent body. For napkins .

<Invention of Claim 5 >
The sanitary napkin according to any one of claims 1 to 4 , wherein the tow in the tow region is cellulose acetate tow.

  Since the tow has a structure in which the fiber arrangement is directional and the gap between the fibers is large with respect to the amount of fibers, when bodily fluid is dropped onto the tow region composed of a fiber assembly made of tow, the bodily fluid Moves into the gap while moving very fast along the fiber flow direction, and therefore has a liquid permeability that is remarkably excellent even when formed thinner than conventional absorbent materials. It is also very light and soft.

However, because tow has a large amount of compression work, if the absorbent body is composed only of tow, it is easy to sag due to pressurization (for example, body pressure when used as a sanitary napkin ). When this occurs, the fibers are in close contact with each other and voids are reduced, making it difficult to recover. If it does so, the high liquid permeability which a tow has will be reduced.

  In the absorbent body of the present invention, the thickness maintaining region supplements the thickness reduction in the toe region and the resulting decrease in stiffness during liquid permeation, and the thickness of the entire absorbent body during pressurization, after pressurization or after liquid permeation There is little decline and the suppression of sag is achieved. Therefore, it is excellent in liquid permeability and soft. In addition, since the tow region does not sag, excellent liquid permeability unique to the tow is maintained.

  In particular, when the tow region and the thickness maintaining region have a laminated structure, the toe region is supported by the thickness maintaining region and has a high liquid permeability that the tow region has, and becomes a less stubborn absorber.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
<Absorber structure>
Absorbent body is a component that is interposed between a liquid-impervious backsheet and a liquid-permeable topsheet in a sanitary napkin , is a flat article having an appropriate thickness, and has a bowl shape, a gourd shape in plan view, An appropriate shape such as an elliptical shape can be used.

  1 to 10 and 26 are plan views of the absorber example X, and FIGS. 11 to 25 and 27 are cross-sectional views in the width direction of the absorber example. The absorbent body X of the present invention comprises a tow region A composed of a fiber assembly made of tow, and a thickness maintaining that is made of an absorbent material other than tow and has a reduced thickness reduction during and after pressurization than the tow region. Regions B and B ′. The toe region A is composed of a fiber assembly made of tows described later. Since the fiber group constituting the toe region A is arranged with directionality and has a large number of voids between the fibers, the body fluid permeability is remarkably superior and the body fluid permeation rate is faster than that of the conventional absorbent material. It is also light and thin. On the other hand, the thickness maintaining regions B and B 'are made of an absorptive material other than tow, for example, a conventionally known absorptive material such as pulp fiber. The thickness maintaining regions B and B ′ are intended to complement thickness reduction during pressurization such as body pressure of the toe region A and to suppress sag caused by the thickness reduction. There is a need to configure less degradation. Whether the thickness reduction is large or small can be expressed by the compression work (WC). When the compression work (WC) is low, the thickness decrease after pressurization or after pressurization is less likely to decrease, but when the compression work (WC) is high, the thickness decrease after pressurization or after pressurization tends to be large. . The compression work (WC) can be measured by, for example, a handy compression tester (KES-G5: manufactured by Kato Tech).

More specifically, in the above-described testing machine, the size and shape of the test piece: 200 mm length × 50 mm width saddle shape, measurement location: 200 mm length × 50 mm width central portion, measurement conditions; SENS: 2, type of force gauge 1 kg, SPEED RANGE: 0.1, DEF sensitivity: 20, pressurization area: 2 cm ² , uptake interval: 0.1 (standard), STROKET SET: 5.0, upper limit load 50 gf / cm ² it can.

The compression work (WC) of the thickness maintaining regions B and B ′ is 1.0 to 3.0 gfcm / cm ^2, and the toe region A is 3.0 to 10.0 gfcm / cm ² . In addition, in order to make the work of compression (WC) between the toe region A and the thickness maintaining regions B and B ′ different within a preferable value range, the thickness maintaining regions B and B ′ are made of a material other than the tow, The density of the tow region is in the range of 10 to 100 kg / m ³ , and the density of the thickness maintaining regions B and B ′ is in the range of 10 to 100 kg / m ³ .

  Next, the arrangement of the tow region A and the thickness maintaining regions B and B ′ in the absorber in the plan view will be described with reference to the plan view. As shown in FIGS. 1 to 10, the toe region A is exposed at least on the front and back surfaces of the absorber X. In this case, for example, when used as an absorbent body such as a sanitary napkin, the exposed surface of the tow region is disposed on the side of use (the side close to the body fluid discharge position), so that body fluid such as menstrual blood is discharged. When it is done, it is quickly absorbed by the tow region A and reaches the thickness maintaining region B to be held and stored. In addition, since the liquid permeability of the toe region A is high, menstrual blood does not stagnate on the surface, and menstrual blood remains on the surface material and gives the user an impression that it is soiled. Furthermore, since the liquid permeability of the site | part close | similar to the use surface side does not fall, it becomes a thing which is hard to leak.

The amount of exposure and the exposure position with respect to the absorber surface can be appropriately changed according to the use mode, for example, the position when incorporated in a sanitary napkin . In addition, it is desirable not to arrange the toe region A in the peripheral portion of the absorber. When the toe region A is located at the peripheral edge, the thickness tends to decrease at the peripheral edge of the absorber, so that the body fluid discharged to the central portion of the absorber easily flows toward the peripheral edge, and the body fluid is absorbed. The risk of spilling out of the body increases.

Preparative c region A, as shown in FIG. 2, arranged so as to extend in the longitudinal direction in the center in the width direction of the absorbent body. The example shown in FIG. 3 is a reference example (example not included in the present invention; the same shall apply hereinafter) that is spot-arranged in a portion with respect to a body fluid discharge site , and the example shown in FIG. It is the reference example made into the shape made narrow.

  By incorporating the absorbent body so that the longitudinal direction of the absorbent body is the longitudinal direction of the sanitary napkin, the toe region A can be easily positioned only in the vicinity of the body fluid discharge site such as the menstrual discharge position, It can also be manufactured at low cost as an inexpensive material.

  Further, the absorbent body X of the present invention may be embossed. The embossing mode is not particularly limited, but when embossing is applied to the tow region A, the liquid permeability of the tow region A is reduced by pressing, which is not desirable.

  As an example of the absorbent body X to which the emboss e is applied, as shown in FIG. 5, in the front and rear of the toe region A arranged in a spot manner, the thickness maintaining region B is linear in the width direction. As shown in FIG. 6 in which the embossed e is provided, a plurality of linear embossed e are provided in the longitudinal direction of the thickness maintaining region B at the front and rear of the toe region A arranged in a spot manner. As shown in FIG. 7, on both sides of the toe region A arranged so as to extend in the longitudinal direction in the central width direction of the absorbent body X, a line along the longitudinal direction with respect to the thickness maintaining region B is provided. As shown in FIG. 8, the embossed e is provided in the shape, on both sides of the tow region A arranged so as to extend in the longitudinal direction in the central width direction of the absorbent body X, with respect to the thickness maintaining region B , Longitudinal center from front of absorber X Form embossing e is attached to the linear toward the along and obliquely rearward from the center portion to the toe region A to, is preferred.

The tow region A can be easily positioned at a body fluid discharge site such as a menstrual discharge position by incorporating the absorbent body X having such an embossed e form so that the longitudinal direction thereof coincides with the longitudinal direction of a sanitary napkin or the like. In addition, the bodily fluid discharged toward the toe region A diffuses along the emboss e, and a sanitary napkin that is difficult to leak sideways can be obtained. Furthermore, when incorporating the absorbent body into the sanitary napkin , a liquid permeable sheet material, a so-called second sheet, may be provided between the absorbent body and the liquid permeable top sheet. In this case, the second sheet and the present invention are provided. It is possible to take a form in which embossing is provided integrally with the absorbent body. For example, as shown in FIGS. 9 and 10, the use surface side of the tow region A arranged in a spot manner is covered with the second sheet S, and the toe region A is surrounded by the second sheet S and the thickness maintaining region B. Thus, a form in which the emboss e is provided in a linear shape is preferable. In such a form, the integrity of the second sheet S and the absorbent body X is enhanced, and a sanitary napkin that suitably exhibits the function of preventing side leakage by embossing and the function of returning the body fluid by the second sheet.

Next, the arrangement of the tow region A and the thickness maintaining regions B and B ′ in the absorbent body in a sectional view will be described with reference to cross-sectional views. As shown in FIGS. 11 to 25, as an example of the cross-sectional structure of the absorber, the thickness maintaining region B is a mode in which the tow region A is exposed on at least the surface of the absorber (the use surface when incorporated in the absorbent article). , B ′ and the toe region A are preferably laminated. In this case, with the exposed surface of the tow area being incorporated in the sanitary napkin so that the use surface of the sanitary napkin is located on the side of the sanitary napkin , the use surface is added from the side and the body pressure causes a slight sag in the toe area. Even if it occurs, since the thickness and the appropriate rigidity of the entire absorbent body are maintained by the thickness maintaining regions B and B ′ where the non-use surface is located on the side, the thickness of the absorbent body as a whole is not reduced and the thickness is lowered. There will be no feeling.

  In the case of such a laminated structure, as shown in FIGS. 11 to 22, if the tow region is positioned in the recess formed on the use surface side of the thickness maintaining region B, the tow region A is taken in. The body fluid is easily diffused and absorbed in the thickness maintaining region B, and the body fluid that is not fully diffused in the toe region A is retained and becomes more permeable, and the body is less likely to leak sideways. Moreover, since the thickness maintenance area | region B is made into the thickness at least in the width direction both sides of an absorber, there exists an effect which supports a body in the thickness part concerned, and it is the structure where the toe area | region A arrange | positioned at a recessed part is hard to sag. is there.

As a specific example of disposing the toe region in this recess, the use surface is pressed against the central part of the wrinkle as shown in the reference example shown in FIG. The form in which the tow region A is arranged, as shown in FIG. 12, the form in which the toe region A in FIG. 11 is formed in a bulky manner, and the use surface is the central part of the hook as in the reference example shown in FIG. Formed by increasing the thickness by folding both sides in the width direction of the sheet-like fiber assembly to the back side (unused side) in the concave part of the thickness maintaining region B where the concave part is formed by pressing, excavation, etc. The form where the tow | toe area | region arrange | positioned was mentioned.

In addition, as in the reference example shown in FIG. 14, the use surface folds back both sides in the width direction of the thickness maintaining region constituent material such as sheet-shaped crimped pulp, and the use surface is recessed in the center portion in the width direction of the wrinkle. 15, a form in which the concave tow region is disposed, a form in which the toe region A in FIG. 14 is formed in a bulky manner as shown in FIG. 15, and a sheet as in the reference example shown in FIG. 16. The use surface is folded back into the width direction both sides of the thickness maintaining region constituent material such as crimped pulp, and the use surface is formed with a recess at the center in the width direction, and the use surface of the recess and the thickness maintaining region B As shown in the reference example shown in FIG. 17, in which the tow regions are stacked over the entire side, both sides in the width direction of the thickness maintaining region constituent material such as sheet-shaped crimped pulp are used. And the concave part is formed in the center of the width direction Forms the concave portion and the toe region surrounds the entire outer surface of the thickness maintaining region B is located may also be mentioned.

Further, as in the reference example shown in FIG. 18, the toe region A is arranged inside the thickness maintaining region B having a substantially C-shaped cross section that opens on the use surface side, and the back surface (non- form the I) and both side portions face used is surrounded, as in the reference example shown in FIG. 19, the toe region a of the sheet-shaped fiber assembly that is contained in the thickness maintaining region in the form shown in FIG. 18 A form in which both side portions are folded on the use surface side, as in the reference example shown in FIG. 20, the tow region A included in the thickness maintaining region in the form shown in FIG. 18 is a sheet-like fiber assembly. The form which is formed by folding both side parts of the sheet to the use surface side, and other absorbent materials are arranged in the folded part. In the absorbent body of the form shown in FIGS. 18 to 20, the body fluid that has penetrated into the tow region A leaks from both sides in the width direction of the toe region because both sides of the toe region in the width direction are surrounded by the thickness maintaining region. since there is no sanitary napkin incorporating the absorption body in this form is extremely side leakage hardly sanitary napkin.

In the above example, the thickness maintaining region B is one region, but it may be composed of a plurality of regions. For example, as in the reference example shown in FIG. 21 , the reference example shown in FIG. 22, and as shown in FIG. 23, the thickness maintaining regions B and B ′ may have a laminated structure. If it is set as the structure shown in FIGS. 21-23, the liquid absorption amount in thickness maintenance area | region B, B 'can be increased, and when it is set as laminated structure, thickness maintenance of each thickness maintenance area | region B, B' is carried out. By appropriately designing the rate, the specification according to the use mode can be obtained. For example, when used in the sanitary napkin down, it is possible to improve the fit.

In addition, it can also be set as the form which does not have a recessed part in a thickness maintenance area | region. If a specific example is shown, the form provided so that the tow | toe area | region A might penetrate the front and back like the reference example shown in FIG. 24, and a sheet-like fiber assembly like the reference example shown in FIG. A form in which both side portions of the tow region A configured by the above are sandwiched by thickness maintaining regions B and B formed by substantially forming a sheet-like thickness maintaining region constituent material as C-folds. In these forms, the toe region A and the thickness maintaining region B do not have a laminated structure in the central portion in the width direction of the absorber, but there is no decrease in thickness of the thickness maintaining region B disposed on both sides of the absorber X. The toe area A does not fall. Moreover, since the thickness as the whole absorber is ensured, a user does not feel thinness.

Note that the tow region A is not limited to one place, and it is configured so that there are a plurality of places as shown in the plan view of the reference example shown in FIG. 26 and the cross-sectional view of the reference example shown in FIG. You can also. The design can be changed as appropriate within the scope of the present invention.

Moreover, the absorber of this invention can also be made into the form on which several tow | toe area | regions A and A were laminated | stacked. Specifically, as in the reference example shown in FIG. 28, the toe area A on the use surface side is formed wider than the toe area A ′ on the back side, as in the reference example shown in FIG. The tow area A on the use surface side and the toe area A ′ on the back surface side have the same width, as in the reference example shown in FIG. 28, the toe area A on the use surface side is more than the toe area A ′ on the back surface side. The form formed narrowly is mentioned. When the plurality of tow regions A and A ′ are provided, in addition to the width of each toe region, the density, bulk, width, denier of the constituent fibers, and the like may be appropriately changed. Further, as in the reference example shown in FIG. 31, a plurality of tow regions A, A ′, A ″ separated in the width direction of the absorber can be arranged. Also in this case, the density, bulk, width, denier of the constituent fibers, etc. of each toe region A, A ′, A ″ can be appropriately designed.

<Composition of fiber assembly>
The fiber assembly used in the present invention is composed of tows (fiber bundles) composed of fibers. Examples of tow fibers include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.). In particular, cellulose esters and cellulose are preferable.

  As cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Regenerated cellulose such as rayon may be used, and the regenerated cellulose may be a spun fiber. The shape and size of cellulose is a continuous fiber that can be regarded as a substantially infinite length and has a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and a particle diameter of about several microns (for example, 1 to 100 μm). Can be selected from various sizes up to a fine powder. Cellulose may be fibrillated, such as beaten pulp.

  Examples of cellulose esters include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate; and polycaprolactone Cellulose ester derivatives such as grafted cellulose ester can be used. These cellulose esters can be used alone or in admixture of two or more. The viscosity average degree of polymerization of the cellulose ester is, for example, about 50 to 900, preferably about 200 to 800. The average substitution degree of the cellulose ester is, for example, about 1.5 to 3.0 (for example, 2 to 3).

  The average degree of polymerization of the cellulose ester can be, for example, 10 to 1000, preferably 50 to 900, more preferably about 200 to 800, and the average degree of substitution of the cellulose ester is, for example, about 1 to 3, preferably 1 to 1. 2.15, more preferably about 1.1 to 2.0. The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability.

  As the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms), particularly cellulose acetate is suitable. The degree of acetylation of cellulose acetate is often about 43 to 62%, but about 30 to 50% is particularly preferable because it is excellent in biodegradability.

  The tow of the present invention may contain other fibers such as rayon fiber, polypropylene fiber, polyethylene fiber, polyester fiber and nylon fiber as long as it contains cellulose ester fiber.

  The tow constituent fiber may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like.

The fineness of the tow constituent fibers can be 1 to 16 denier, preferably 1 to 10 denier, and more preferably about 2 to 8 denier. Tow constituent fibers is Ru crimped fibers der. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used. When crimped fibers are used, a bulky and light absorbent body can be produced, and a tow with high unity can be easily produced by entanglement between the fibers. The cross-sectional shape of the tow constituting fiber is not particularly limited, and may be any one of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good. The tow constituting fibers are used in the form of tows (fiber bundles) formed by bundling, for example, about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. can do. The fiber bundle is preferably formed by bundling about 3,000 to 1,000,000 continuous fibers.

  Since the tow is weak in entanglement between fibers, a binder can be used mainly for the purpose of maintaining the shape by connecting the fibers with dots, lines or spots. Examples of binders include triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate ester plasticizers, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force when melted and solidified, and includes a water-insoluble or hardly water-soluble resin and a water-soluble resin. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or poorly water-soluble resins include polyethylene, polypropylene, ethylene-propylene copolymers, olefinic homo- or copolymers such as ethylene-vinyl acetate copolymers, polyvinyl acetate, polymethyl methacrylate, methacryl Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, optionally modified polyesters, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (eg, rosin esters), Hydrocarbon resin (eg terpene tree , Dicyclopentadiene resins, and petroleum resins), and hydrogenated hydrocarbon resins. One or two or more of these thermoplastic resins can be used.

  Examples of water-soluble resins include various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group, or a salt thereof. Vinyl water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxides, water-soluble polyesters, water-soluble polyamides, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents may be added to the thermoplastic resin.

  Moreover, the superabsorbent polymer may be interspersed inside or at least one of the surface of the fiber assembly. As the superabsorbent polymer, a polymer that absorbs and retains bodily fluids, for example, ten times or more of its own weight can be used. Examples include starch-based, cellulose-based and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, cross-linked sodium carboxymethyl cellulose and acrylic acid. A (salt) polymer or the like can be used. As the shape of the superabsorbent polymer, a commonly used granular material is suitable.

The superabsorbent polymer can be appropriately determined according to the amount of absorption required for the use of the absorber. Thus can not be said sweepingly, for example, it can be sprayed so as to 3~400g / m ² in the case of the sanitary napkin down.

  The quantitative arrangement of the superabsorbent polymer with respect to the fiber assembly, the density distribution, and the fiber density are preferably uniform for the purpose of general purpose, but when aiming to exhibit special absorption characteristics, It is also preferable to bias according to the purpose.

  Moreover, since a fiber assembly becomes easy to flow a liquid along the continuous direction of a fiber, it can provide a special absorption characteristic by biasing the density of a fiber. Such a means for biasing the fiber density can be achieved by performing uneven fiber opening at the time of manufacturing the fiber assembly or by using a plurality of tows in a bundle. As a specific method of biasing, for example, the fiber density of the intermediate portion in the width direction of the fiber assembly can be biased so as to be higher than both side portions. In this case, more liquid flows along the continuous direction of the fibers in the intermediate portion in the width direction of the fiber assembly.

<Method for producing fiber assembly>
A fiber assembly made of tows constituting the tow region A can be produced by a known method, and if necessary, it can be opened in a strip shape so as to have a desired size and bulk. The opening width of the tow is arbitrary, and can be, for example, about 100 to 2000 mm, preferably about 150 to 1500 mm. Opening the tow is preferable because the movement of the superabsorbent polymer described later becomes easier. Further, the rigidity of the absorbent body can be adjusted by adjusting the degree of tow opening.

  As a method for opening a tow, for example, a method in which a tow is passed over a plurality of opening rolls and the width of the tow is gradually expanded as the tow progresses, and tension (elongation) and relaxation of the tow ( (Shrinkage) can be repeated, and a method of widening and opening using compressed air can be used.

  In addition, as a method of dispersing the superabsorbent polymer in the fiber assembly, after spreading the superabsorbent polymer on the widened and opened fiber assembly, the surface opposite to the sprayed surface is sucked drum, etc. And a method of moving the dispersed polymer to the inside by suctioning with an appropriate suction force.

  In particular, in manufacturing a fiber assembly used for an absorbent body in which a plurality of tow regions A and A ′ as shown in the reference examples shown in FIGS. 28 to 31 are laminated, as shown in FIG. The tow A1 and the tow A2 that have been opened are made into a laminated state by two pairs of rolls R1, R1, and R2, R2, and then cut to an appropriate size. Further, in manufacturing a fiber assembly used in an absorbent body in which a plurality of tow regions as shown in FIG. 31 are provided in the width direction, as shown in FIG. 33, tows A4 constituting the toe region A, The tows A3 constituting the toe area A ′ and the tows A5 constituting the toe area A may be gathered by various rollers R3 to R5, and then cut to an appropriate size.

<About thickness maintenance area>
A conventionally known absorbent material can be used as the material constituting the thickness maintaining regions B and B ′, and the manufacturing method can also be manufactured by a conventionally known manufacturing method. However, since the thickness maintaining regions B and B ′ are intended to improve the decrease in the thickness maintaining rate of the entire absorber due to the arrangement of the toe region, the thickness maintaining rate is low in relation to the toe region. It is not desirable to be made of such a material.

Thickness maintenance region B, as the specific material B ', pulverized pulp the pulp fibers as a raw material, and crimping pulp, cotton fibers, nonwoven fabric or made of chemical fiber, porous foam materials is Ru is used. Of course, also in the thickness maintenance regions B and B ′, a superabsorbent polymer of the same type as the above-described fiber assembly may be interspersed.

  On the other hand, in the thickness maintenance area | region B, when providing a recessed part, a recessed part can be provided by the embossing by a convex roll, or excavation with a drilling apparatus. It can also be formed by folding back both sides of the sheet-like thickness maintaining region constituent material. Preferably, it is desirable to give a larger core embossing and to give a fine embossing finer than the core embossing to the core embossing giving surface. When the fine embossing is formed, the contact surface between the thickness maintaining region B and the toe region is widened, so that the body fluid is quickly transferred from the toe region to the thickness maintaining region B, and the thickness recoverability of the toe region is improved.

  On the other hand, when providing a tow region so that the toe region A penetrates the front and back surfaces of the absorber, an appropriate position of the thickness maintaining region B may be drilled to provide a through hole. The excavation method is not particularly limited, and may be performed by an apparatus used for molding and processing an appropriate absorbent material.

<Method for producing absorber>
The absorbent body of the present invention is formed by laminating the above-described tow region constituent material and the thickness maintaining region constituent material, or arranging the tow region constituent material in a drilling hole formed in the thickness maintaining region constituent material and appropriately bonding the laminated body. After being integrated by adhering with an agent or the like, according to a known technique, it can be appropriately cut into a size and individually packaged with a known liquid-permeable sheet. The tow region component and the thickness maintaining region component are not bonded to each other, and the tow region component and the thickness maintaining region component are stacked and laminated, or in the excavation hole formed in the thickness maintaining region component After the components are arranged, they can be manufactured by appropriately cutting them according to known techniques. Further, it may be individually packaged with a known liquid-permeable sheet or the like.

  When the tow region and the thickness maintaining region have a laminated structure, the fiber material constituting the thickness maintaining region made of pulp or the like and the superabsorbent polymer are towed with a known fiber stacking device or layering device. After the fibers are accumulated on the fiber aggregate constituting the region A, it can be appropriately cut and manufactured. It may be individually packaged later.

In addition, the sheet | seat for individual packaging is not contained in the absorber in this invention. When used for a sanitary napkin or the like, it may be used in a form surrounded by a liquid-permeable sheet, but such a surrounding sheet is a part not included in the absorbent body of the present invention.

<Method for producing sanitary napkin >
About sanitary napkin and a manufacturing method thereof absorber described below. 34 and 35 show a _first form N ₁ of a sanitary napkin having an absorbent body. As can be understood from the plan view from the use surface side shown in FIG. 34, the sanitary napkin N ₁ of the first embodiment has both the thickness maintenance region B and the toe region A at the longitudinal end of the sanitary napkin. Furthermore, as shown in FIG. 35 which is a V ₁ -V ₁ cross-sectional view of FIG. 34, the thickness maintaining region B and the toe region A are laminated and the toe region A is positioned on the use surface side. It is a form.

A method for producing this form of sanitary napkin N ₁ is shown in FIG. First, the adhesive G is applied to an appropriate position of use surface side in the thickness maintaining region constituting material band B _O of fiber stacking pulp sheet or the like for construction of the thickness maintaining region B conveyed by the conveyor or the like from the upstream, The tow region constituting material band _AO constituting the tow region A is continuously laminated and bonded. Next, the laminated absorbent band X _O is cut into an appropriate size by the cutters 10 and 10 to form the absorbent bodies X, X... Then conveyed to the surface side of the absorber X (use side) the topsheet material band t _O, downstream with a conveyor or the like while superposed backsheet material band b _O on the back side. Next, the top sheet material band t _O and the back sheet material band b _O are bonded at appropriate intervals by the hot melt bonding apparatuses 11 and 11, and appropriately cut by the hot melt bonding portion H to be used for each sanitary napkin N. _{Get one} . In addition, a hot-melt-bonding part comprises the longitudinal direction edge part of a sanitary napkin.

Next, FIGS. 37 and 38 show a second form N ₂ of the sanitary napkin having the absorbent body X. As can be understood from the plan view from the use surface side shown in FIG. 37, the sanitary napkin N ₂ of the second embodiment has a thickness maintaining region B that does not reach the longitudinal end of the sanitary napkin. The tow region A reaches the longitudinal end of the sanitary napkin , and as shown in FIG. 38 which is a V ₂ -V ₂ cross-sectional view of FIG. 37, the thickness maintaining region B and the toe region A And the toe region A is positioned on the use surface side.

A method for producing this sanitary napkin N ₂ is shown in FIG. First, the thickness maintenance area constituting material band B _X of fiber stacking pulp sheet or the like for construction of the thickness maintaining region B conveyed from the upstream at a conveyor or the like and cut into a suitable size with a cutter 10, 10 Thickness maintaining region constituent materials X _B , X _B ... Are formed and further conveyed downstream. Next, an adhesive G is applied to an appropriate portion on the use surface side of the thickness maintaining region constituent materials X _B , X _B ..., And the tow region constituent material strip A _O constituting the toe region A is continuously laminated. Transport downstream while adhering. Next, the top sheet material band Nt on the front surface side (use surface side) and the back sheet material band Nb on the back surface side of the absorber band X _O in which the toe region component material band A _O is laminated on the thickness maintaining region component material X _B. Are conveyed downstream by a conveyor. Next, the top sheet material band Nt and the back sheet material band Nb are bonded with a hot melt bonding device at appropriate intervals, and appropriately cut with the hot melt bonding portion to obtain individual sanitary napkins N ₂ .

Next, FIGS. 40 and 41 show a third form N ₃ of a sanitary napkin having an absorbent body. In the sanitary napkin N ₃ of the third form, as can be understood from the plan view from the use surface side shown in FIG. 40, the thickness maintaining region B reaches the longitudinal end of the sanitary napkin N _3. The tow region A is spot-arranged at the center of the thickness maintaining region B, and as shown in FIG. 41 which is a V ₃ -V ₃ sectional view of FIG. 40, the thickness maintaining region B The tow region A surrounded by the crepe paper C is laminated and positioned on the use surface side of the sheet. A part of the manufacturing method of the third embodiment is shown in FIG. First, applying the adhesive G at an appropriate position of use surface side of the crepe paper band C _O conveyed from upstream. Next, a tow region constituent material band A _O having a narrower width than that of the crepe paper band C _O is continuously superimposed on the use surface side, and conveyed downstream. Thereafter, the folding device 12 at crepe paper band C both sides surrounded to the absorber constituting material bands toe region constituting material zone A _O folded over the use surface side in crepe paper band toe region constituting material zone A _O of _O Form. And thereafter cutting the absorbent structure material strip to a suitable size and absorbent structure material A _X. Then, although not shown, or to place the absorbent structure material A _X to use surface side of a suitable size Thickness maintaining region structure material, or by cutting after placed on the use surface side in the thickness maintaining region constituting material strip The absorber X is manufactured. Thereafter, the top sheet material band is superimposed on the front surface side (use surface side) of the absorbent body X, and the back sheet material band is overlapped on the back surface and conveyed downstream by a conveyor. The sheet material strip Nb is bonded with a hot melt bonding apparatus, and cut with the hot melt bonding portion to obtain individual sanitary napkins N ₃ .

<Others>
The specific size, thickness rigidity, etc. of the absorbent body of the present invention are not particularly limited, and can be appropriately changed depending on the type of sanitary napkin to be incorporated.

The present invention is applicable to the physiology napkin down.

It is a top view which shows the 1st form of an absorber roughly. It is a top view which shows the 2nd form of an absorber roughly. It is a top view which shows the 3rd form of an absorber roughly. It is a top view which shows roughly the 4th form of an absorber. It is a top view which shows the 5th form of an absorber roughly. It is a top view which shows the 6th form of an absorber roughly. It is a top view which shows roughly the 7th form of an absorber. It is a top view which shows the 8th form of an absorber roughly. It is a top view which shows roughly the 9th form of an absorber. It is a top view which shows roughly the 10th form of an absorber. It is sectional drawing which shows roughly the 11th form of an absorber. It is sectional drawing which shows roughly the 12th form of an absorber. It is sectional drawing which shows roughly the 13th form of an absorber. It is sectional drawing which shows roughly the 14th form of an absorber. It is sectional drawing which shows roughly the 15th form of an absorber. It is sectional drawing which shows roughly the 16th form of an absorber. It is sectional drawing which shows roughly the 17th form of an absorber. It is sectional drawing which shows roughly the 18th form of an absorber. It is sectional drawing which shows roughly the 19th form of an absorber. It is sectional drawing which shows roughly the 20th form of an absorber. It is sectional drawing which shows the 21st form of an absorber roughly. It is sectional drawing which shows roughly the 22nd form of an absorber. It is sectional drawing which shows roughly the 23rd form of an absorber. It is sectional drawing which shows roughly the 24th form of an absorber. It is sectional drawing which shows roughly the 25th form of an absorber. It is a top view which shows roughly the 26th form of an absorber. It is VV sectional drawing of the 26th form of an absorber. It is sectional drawing which shows roughly the 27th form of an absorber. It is sectional drawing which shows schematically the 28th form of an absorber. It is sectional drawing which shows roughly the 29th form of an absorber. It is sectional drawing which shows roughly the 30th form of an absorber. It is the schematic which shows the manufacturing method of the fiber assembly of a laminated structure. It is the schematic which shows the manufacturing method in the case of juxtaposing several fiber aggregates in the width direction. It is a top view which shows roughly the 1st form of the sanitary napkin which has an absorber. It is sectional drawing which shows schematically the 1st form of the sanitary napkin which has an absorber. It is the schematic for demonstrating the manufacturing method of the 1st form of the sanitary napkin which has an absorber. It is a top view which shows roughly the 2nd form of the sanitary napkin which has an absorber. It is sectional drawing which shows schematically the 2nd form of the sanitary napkin which has an absorber. It is the schematic for demonstrating the manufacturing method of the 2nd form of the sanitary napkin which has an absorber. It is a top view which shows roughly the 3rd form of the sanitary napkin which has an absorber. It is sectional drawing which shows schematically the 3rd form of the sanitary napkin which has an absorber. It is the schematic for demonstrating the manufacturing method of the 3rd form of the sanitary napkin which has an absorber.

  A ... Toe region, B, B '... Thickness maintenance region, e ... Emboss, S ... Second sheet, X ... Absorber. t: liquid-permeable top sheet, b: liquid-impervious back sheet, H: adhesive portion.

Claims (5)

In a sanitary napkin in which an absorbent for absorbing and holding bodily fluid is interposed between a liquid-impermeable back sheet and a liquid-permeable top sheet,
The absorbent body includes a toe area composed of tow 1-16 denier crimped continuous fibers in being that fiber aggregate obtained by spreading, pulp fibers, porous foam, cotton fibers, nonwoven least a And a thickness maintaining region made of an absorbent material other than tow and having a smaller work of compression (WC) than the tow region,
The thickness maintaining region has a compression work (WC) of 1.0 to 3.0 gfcm / cm ² and a density of 10 to 100 kg / m ³ .
The tow region has a compression work (WC) of 3.0 to 10.0 gfcm / cm ² and a density of 10 to 100 kg / m ³ .
The thickness maintaining region is provided so as to extend across the widthwise central portion of the absorber and both side portions thereof.
The tow region is disposed so as to extend in the longitudinal direction at the center in the width direction of the absorber,
A concave portion is provided on the side surface of the top sheet of the thickness maintaining region in the central portion in the width direction, and the tow region is provided in the concave portion so as to be exposed on the surface of the absorber .
The exposed portion of the surface of the toe region in the central portion in the width direction of the absorber protrudes toward the top sheet side than the side surface of the top sheet in the thickness maintaining region .
A sanitary napkin characterized by that. The sanitary napkin according to claim 1, wherein the absorbent body has portions formed by folding the use surface of both sides in the width direction of the constituent material constituting the thickness maintaining region on both sides in the width direction of the absorbent body. The said recessed part is not provided in the said thickness maintenance area | region, The said tow | toe area | region is provided in the said width direction center part so that the said thickness maintenance area | region may be penetrated from the surface to a back surface. Sanitary napkin . The physiology according to any one of claims 1 to 3 , wherein the tow region extends along the longitudinal direction at a central portion in the width direction of the absorbent body within a range not reaching the peripheral edge of the absorbent body. For napkins . The sanitary napkin according to any one of claims 1 to 4 , wherein the tow in the tow region is cellulose acetate tow.

Images