JP2006014880A5 - - Google Patents

Description

Absorbent articles

  The present invention relates to absorbent articles such as paper diapers and sanitary napkins.

  Conventionally, an absorbent body used for an absorbent article is formed by stacking short pulp fibers and superabsorbent polymer particles on a stacking drum and then wrapping them with an absorbent sheet such as crepe paper. On the other hand, in recent years, it has been proposed to use a tow (fiber bundle) composed of fibers as an absorbent body instead of a short fiber stack (see, for example, Patent Document 1).

However, although the tow is very excellent in the liquid permeability, the liquid diffusibility is inferior to the permeability (a certain degree of diffusivity is exhibited when the liquid is held). For this reason, in the absorber using the conventional tow, there is a possibility that the portion used for absorption may be limited, and in this case, leakage due to a small absorption capacity or from the absorber to the skin side of the wearer It is easy for reversal to occur.
JP 2001-524399 A

  Therefore, the problem to be solved by the present invention is to make it possible to use a wider part of the absorber for absorption, thereby suppressing leakage and reversion.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In an absorbent article having an absorber including a fiber assembly made of tow and a surface side layer provided on the surface side of the absorber,
An absorbent article comprising a continuous linear groove at least on the surface side layer.

(Function and effect)
Thus, when a continuous linear groove is provided in the surface side layer, the liquid excreted from the wearer comes to diffuse through the groove in the surface side layer before reaching the absorber having poor diffusibility, A wider part of the absorber becomes available for absorption. Accordingly, the absorbent capacity is increased, and the absorbent article is less likely to leak or reverse.

  In other words, in the present invention, the diffusibility in the surface side layer is improved, so that the diffusibility in the absorbent body can be reduced. For example, the fiber density of the fiber assembly is reduced or a large amount of the superabsorbent polymer is added. By using it for absorption, the absorption capacity can be increased.

  In the present invention, the “surface side” means a surface side in contact with the wearer's skin.

<Invention of Claim 2>
The said surface side layer is at least one of the surface sheet which contacts a wearer's skin, the 2nd sheet provided between the surface sheet and the absorber, and the sheet | seat which wraps the said fiber assembly. Absorbent articles.

(Function and effect)
In the absorbent article, a surface sheet that comes into contact with the skin is generally provided on the surface side of the fiber assembly. Moreover, in order to bring about the intended change in absorption performance, for example, improvement in diffusibility due to the internal structure of the material, a second sheet may be provided between the top sheet and the absorbent body. Further, the absorbent body may be configured by wrapping the fiber assembly with water absorbent paper. In the present invention, the above-described effects can be exhibited by forming a groove in at least one of these sheets.

<Invention of Claim 3>
The absorbent article according to claim 1 or 2, wherein at least one groove is provided along at least one of the longitudinal direction of the article and the width direction of the article.

(Function and effect)
In the absorbent article, the front and rear ends of the article are particularly difficult to be used for absorption. Therefore, when the groove of the present invention is formed along the front-rear direction of the article, a wider part of the absorber can be used for absorption, and the amount of diffusion in the width direction is reduced, so-called lateral leakage. There is also an effect of suppressing.

  Further, since the absorbent article is in a position where the excretion position is low in the mounted state and the front and rear sides thereof are located in high places, the liquid to be diffused in the width direction is distant from the excretion position. Will descend to the side. That is, in the absorbent article, diffusion in the width direction is difficult depending on the position. Therefore, it is also a preferable form to provide the groove of the present invention along the width direction of the article.

<Invention of Claim 4>
The absorbent article according to any one of claims 1 to 3, wherein the groove is formed by compressing the surface side layer.

(Function and effect)
Since the groove formed by the compression process causes a decrease in liquid permeability due to an increase in material density, particularly at the bottom, the liquid does not permeate and easily diffuses along the groove. Therefore, according to the invention described in this section, the diffusibility can be further improved.

  As described above, according to the present invention, a wider part of the absorber can be used for absorption, and thus leakage and reversion can be suppressed.

  Hereinafter, the embodiment of the present invention will be described in detail based on an application example to a tape-fixed paper diaper. However, it goes without saying that the present invention can be applied to other absorbent articles such as a pants-type paper diaper and a sanitary napkin. .

(Structural example of absorbent article)
FIG.1 and FIG.2 has shown the fixed-type paper diaper which this invention makes object. In this example of a paper diaper, for example, a rectangle is placed between a liquid-permeable top sheet 1 positioned on the user's skin side and a liquid-impermeable back sheet 2 positioned outside the product and substantially impermeable to liquid. Or, preferably, an absorber 3 having a certain degree of rigidity of an hourglass shape is provided as shown.

  The back sheet 2 has a rectangular shape wider than the absorbent body 3, and an exterior sheet 6 made of a nonwoven fabric or the like is provided on the outer surface of the back sheet 2 in order to improve touch. The back sheet 2 can be formed of a plastic film such as a polyethylene film.

  On the other hand, the top sheet 1 has a rectangular shape wider than the absorbent body 3, extends slightly outward from the side edge of the absorbent body 3, and is bonded to the back sheet 2 by a hot melt adhesive (this fixing portion is Including, the fixed portion related to this embodiment is indicated by a symbol *). As the surface sheet 1, various nonwoven fabrics such as a spunbond nonwoven fabric, an air-through nonwoven fabric, an SMS nonwoven fabric, and a point bond nonwoven fabric, a plastic film such as a polyethylene film, and a laminated nonwoven fabric obtained by laminating a plastic film and a nonwoven fabric can be used. Moreover, a net-like material in which yarns such as nylon and polyethylene terephthalate are plain woven can be used.

  The absorber 3 can be wrapped at least by a liquid-permeable sheet 3s having liquid permeability, such as crepe paper, non-woven fabric, and perforated sheet. In particular, an absorbent sheet 3s such as crepe paper is preferably used.

  Between the surface sheet 1 and the absorbent body 3, a second sheet 8 made of a non-woven fabric is provided for the purpose of quickly diffusing body fluid that has passed through the surface sheet 1 to a wide range or quickly moving to the absorbent body 3. Can do. As the second sheet 8, a non-porous or perforated nonwoven fabric, a short fiber or a long-fiber nonwoven fabric, a mesh-like film, or the like can be used. When using a nonwoven fabric, water retention fibers, such as rayon and a cellulose derivative, can be included in a nonwoven fabric, or a hydrophilic agent can be added. When a nonwoven fabric is used, one having a fiber density smaller than that of the top sheet 1 is suitable. For example, one having a fineness exceeding 2.1 dtex, particularly exceeding 2.1 dtex and not exceeding 11.0 dtex can be used. Nonwoven fabric materials that can be used for the second sheet 1X include polypropylene, polyethylene, polyethylene terephthalate, polyamide, nylon, rayon, vinylon, acrylic, and the like. Can be suitably employed. The short fibers can be joined by a wet method, a dry method (air lay method or card method), a spun lace method, or the like, which can be entangled by point bonding, water flow, needles or the like with heat or an adhesive. Nonwoven fabrics composed of core / shell and side-by-side composite fibers can also be mentioned, and examples of the composite fibers include polyethylene terephthalate / polyethylene, polypropylene / polyethylene, and polypropylene / polypropylene.

  On the other hand, standing leg cuffs 9 for protruding around the use surface can be provided on both sides of the paper diaper. The standing cuff 9 can be formed by a side sheet 4 made of a nonwoven fabric substantially continuous in the width direction, and one or a plurality of elastic elastic members 5 such as thread rubber as shown. The side sheet 4 is preferably not liquid-permeable but substantially liquid-impervious (may be semi-liquid-permeable). For example, a sheet or the like obtained by subjecting a nonwoven fabric to a water-repellent treatment by silicon treatment or the like. Can be used. When the diaper is worn, the diaper forms a boat shape along the body and the contraction force of the elastic elastic members 5, 5... Acts to raise the standing cuff 9 around the leg and become a barrier. Side leakage is prevented.

  Further, the illustrated paper diaper is a tape-fixed paper diaper, and has a fastening piece 7A on each side end portion of the back side portion, and this fastening piece 7A is provided on the abdominal side surface. By fastening to, a waist opening and a pair of leg openings are formed. In the case of a pants-type diaper, instead of omitting these fastening means, both side edges of the abdominal part and the back part are joined in advance by joining means such as heat seal.

(About absorber)
The present invention is based on the premise that the absorbent body 3 includes a fiber assembly 10 made of tow. Examples of fibers constituting the fiber aggregate 10 made of tow (hereinafter simply referred to as tow constituent fibers) include, for example, polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, Polyamide, polyester, polylactamamide, polyvinyl acetate, etc.) can be used, and cellulose ester and cellulose are particularly 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 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, for example, about 1 to 16 denier, preferably about 1 to 10 denier, and more preferably about 2 to 8 denier. The tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. 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 constituent fibers are used, for example, in the form of tows (fiber bundles) formed by bundling 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 entanglement between fibers is weak, a binder having an action of adhering or fusing the contact portions of the fibers can be used mainly for the purpose of maintaining the shape. The binder includes triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester, and other plastic resins, as well as various resin adhesives, especially thermoplastic resins. Can be used.

Thermoplastic resins, the adhesive strength is a resin expressed, are water-insoluble or sparingly water-soluble resins, and water-soluble resin by the melt and solidification. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or hardly water-soluble resins include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer and other olefinic homo- or 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, polyesters that may be modified, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (for example, 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.

  The fiber assembly 10 of the present invention made of tow can be produced by a known method, and in this case, in the present invention, the fiber assembly 10 is opened 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.

The density of the fiber assembly 10 can be adjusted by adjusting the degree of tow opening . The fiber aggregate 10 of the present invention, the fiber density at the time of a thickness of 10mm is 0.0075 g / cm ³ or less, is suitable as a particularly 0.0060~0.0070g / cm ^3. When the fiber density is excessively high, the advantage of using the fiber assembly 10 made of tow is reduced, and for example, it is difficult to reduce the weight and thickness. Further, the basis weight of the fiber assembly 10 of the present invention is preferably 0.0075 g / cm ² or less, particularly 0.0060 to 0.0070 g / cm ² . The fiber basis weight can be adjusted by selecting a tow serving as a raw fabric or manufacturing conditions thereof.

  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.

  FIG. 3 is a schematic view showing an example of the opening facility. In this example, the tow 11 serving as a raw fabric is sequentially fed out, and in the conveying process, a widening means 12 using compressed air and a plurality of spread nip rolls 13, 14, and 15 whose peripheral speed is faster as the downstream side roll is combined. After passing through the opened portion and widened / opened, the fiber is passed through the binder addition box 16 and added with a binder (for example, filling the box with a mist of triacetin), and a fiber made of tow having a desired width and density. It is formed as an aggregate 10.

  The fiber assembly 10 made of tow can contain a superabsorbent polymer. Examples of the superabsorbent polymer include carboxymethyl cellulose, polyacrylic acid and salts thereof, crosslinked acrylate polymer, starch-acrylic acid graft copolymer, starch-acrylonitrile graft copolymer hydrolyzate, polyoxyethylene A cross-linked product, a cross-linked product of carboxymethyl cellulose, a partially cross-linked columnar polymer such as polyethylene oxide and polyacrylamide, or a copolymer of isobutylene and maleic acid is preferably used. What added the blocking inhibitor in order to suppress the blocking property by moisture absorption of a product can also be used. In addition, the superabsorbent polymer has various forms such as powder, particles, granules, pellets, sol, suspension, gel, film, and nonwoven fabric. Any of them can be used in the present invention, and a particulate material is particularly preferably used.

The method for incorporating the superabsorbent polymer, how you spread superabsorbent polymer particulate to the fiber aggregate 10 of tows, and the monomer (superabsorbent polymer fiber aggregate 10 of tows For example, a method of polymerizing after impregnating with a non-crosslinked gel-like superabsorbent polymer on the fiber aggregate 10 made of tow, and a method of performing a crosslinking treatment. The basis weight of 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, typically 0.03 g / cm ² or less, particularly preferably be a 0.01~0.025g / cm ^2.

  Further, instead of containing the superabsorbent polymer in the fiber assembly 10 or including the superabsorbent polymer in the fiber assembly 10, the front side and the back side of the fiber assembly 10 made of tow A superabsorbent polymer may be provided in a layer form on at least one of the above. In particular, it is preferable to provide a superabsorbent polymer layer on the back side of the fiber assembly 10. In these cases, the superabsorbent polymer can be bonded to the sheet 3 s enclosing the fiber assembly 10 with an adhesive. As the adhesive in this case, the aforementioned thermoplastic resin can be used.

  Further, as shown in FIGS. 4A and 4B, the fiber assembly 10 is preferably provided so that the fiber continuous direction (represented by a straight line) of the tow is along the front-rear direction of the article. As shown in 4 (c) (d), the fiber continuous direction of the tow can be provided along the width direction of the article. In addition, the code | symbol DP in FIG. 10 has shown the paper diaper, and the code | symbol NP has shown the sanitary napkin.

(About surface side layer with grooves)
Moreover, in this invention, a continuous linear groove | channel is provided in the surface side layer provided in the surface side of the absorber 3. FIG. As this surface side layer, in the paper diaper of the said embodiment, the sheet | seat 3s which wraps the surface sheet 1, the 2nd sheet | seat 8, and the fiber assembly 10 corresponds. In the present invention, a continuous linear groove 20 is formed in any one, two or more or all of them. Providing the groove 20 in the top sheet 1 is advantageous in that the body fluid can be diffused earlier. Further, if the groove is provided in the sheet 3s that wraps the second sheet 8 or the fiber assembly 10, the liquid can be diffused at a position farther from the skin, which is advantageous in that the wet feeling is softened. In consideration of the balance between the ease of manufacture and the effect, it is preferable to provide the groove 20 on the top sheet 1 or the second sheet 8 alone or on both sheets 1 and 8.

The form of the groove 20 of the present invention can be appropriately determined mainly in consideration of the diffusion direction of the body fluid. For example, the following form can be adopted.
(1) A form in which grooves 20 are provided along the longitudinal direction of the article as shown in FIG.
(2) A form in which the groove 20 is provided along the article width direction as shown in FIG.
(3) As shown in FIG. 1 and FIG. 2, a form in which the grooves 20 are provided in a plurality of rows at appropriate intervals.
(4) As shown in FIG. 6, a form in which a plurality of rows of grooves 20 along the article longitudinal direction and a plurality of rows of grooves 20 along the article width direction are provided to intersect (that is, a form in which grooves 20 are provided in a lattice shape).
(5) A form in which, as shown in FIG. 7, a plurality of rows of grooves 20 are provided along the front-rear direction of the article, and grooves 20 are provided along the article width direction only at the front-rear side of the article.
(6) The form which provided the groove | channel 20 cyclically | annularly so that an excretion position may be enclosed as shown in FIG.

The range in which the groove 20 of the present invention is provided can be determined as appropriate in consideration of the diffusion range of body fluid. For example, the following forms can be adopted.
(1) The entire target sheet or substantially the entire sheet (for example, 80% or more in area ratio).
(2) As shown in FIG. 9, only a part of the target sheet, for example, only the middle part or both end parts in the longitudinal direction or the width direction of the article.
(3) As shown in FIG.

  The number of the grooves 20 of the present invention may be determined as appropriate, and may be one, but it is preferable to provide a plurality of grooves, particularly three or more, and it is particularly preferable to provide three or more grooves along the longitudinal direction of the article. It is a form.

  The length, width, depth of the groove 20 of the present invention, and the interval when a plurality of grooves 20 are provided can be set as appropriate. Although these dimensions cannot be determined unconditionally, in a normal form of a paper diaper or a sanitary napkin, the length of the groove 20 is preferably 50 mm to 1000 mm, particularly preferably 70 mm to 700 mm. The width of the groove 20 is preferably 0.5 mm to 50 mm, particularly 1 mm to 20 mm. The depth of the groove 20 is preferably 0.05 mm to 10 mm, particularly preferably 0.1 mm to 5 mm. Further, the interval between the grooves 20 is preferably 0.5 mm to 150 mm, particularly 1 mm to 50 mm.

  The groove 20 of the present invention may be formed by manufacturing the material itself so as to have the groove 20 (for example, manufacturing in a corrugated cross section). However, the target member is compressed by embossing or the like in an appropriate manufacturing process. It is preferable to form by processing. In this case, in addition to forming the groove 20 by a continuous linear pattern, a pattern in which a large number of dot-like compression portions 21 are connected as shown in FIG. 10 is adopted, and the compression portions 21 come close to each other to form a continuous linear shape. A method of forming the groove 20 can also be adopted.

  In the present invention, when the grooves 20 are provided in a plurality of sheets, the shape of the grooves 20 can be varied. For example, the groove 20 can be extended along the front-rear direction of the article in the top sheet 1, and the groove 20 can be extended along the width direction in the second sheet 8.

It is a top view of the paper diaper of an unfolded state. It is II-II sectional drawing of FIG. It is a manufacturing flow figure of the fiber assembly which consists of tows. It is a top view which shows roughly the example of the continuous direction of the tow fiber in an absorbent article. It is a top view of another example of a paper diaper. It is a top view of another example of a paper diaper. It is a top view of another example of a paper diaper. It is a top view of another example of a paper diaper. It is a top view of another example of a paper diaper. It is a top view which shows the example of the groove | channel by compression processing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Surface sheet, 2 ... Back surface sheet, 3 ... Absorber, 3s ... Sheet which wraps fiber assembly, 4 ... Side sheet, 5 ... Elastic elastic member, 6 ... Exterior sheet, 7A ... Fastening piece, 7B ... Target tape , 8 ... Second sheet, 9 ... Standing cuff, 10 ... Fiber assembly, 20 ... Groove, 21 ... Compression section.

Claims (4)

In an absorbent article having an absorbent body including a fiber assembly made of tow and a surface side layer provided on the surface side of the absorbent body ,
An absorbent article comprising a continuous linear groove at least on the surface side layer.   The said surface side layer is at least one of the surface sheet which contacts a wearer's skin, the 2nd sheet provided between the surface sheet and the absorber, and the sheet | seat which wraps the said fiber assembly. Absorbent articles.   The absorbent article according to claim 1 or 2, wherein at least one groove is provided along at least one of the longitudinal direction of the article and the width direction of the article.   The absorbent article according to any one of claims 1 to 3, wherein the groove is formed by compressing the surface side layer.