JP4394616B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article in which an absorbent body is formed by a filament aggregate formed by opening a tow.

  Absorbent articles such as infant and adult tape-type and pants-type disposable diapers and sanitary napkins are used between the top sheet on the use side, the back sheet that prevents permeation of body fluids on the back side, and between these sheets. The basic element is an absorption element that receives and holds excreted body fluid that has permeated through the top sheet.

  For this basic element, an exterior sheet made of, for example, a non-woven fabric is provided on the back side of the back sheet, and a form for improving the touch when a plastic sheet is used as the back sheet, a form for forming so-called barrier cuffs on both sides of the product, etc. In order to improve the fit around the waist and the abdomen, a form for imparting elastic stretchability is appropriately added.

  As an absorbent element that receives and holds the body fluid that has passed through the top sheet on the use surface side, conventionally, a fiber stack of pulp staple fibers is generally used. It is also known to use superabsorbent polymer particles (hereinafter also referred to as “SAP”) to increase the amount of body fluid absorbed.

  In addition to the case where the SAP is dispersed on the piled fiber of short pulp fibers, there are cases where the SAP of the short pulp fibers is dispersed and held (Patent Document 1).

  On the other hand, in recent years, as shown in JP-T-2002-524399 (WO99 / 27879: Patent Document 2) and JP-T-2004-500165 (US Pat. No. 6,646,180: Patent Document 3), cellulose acetate It has been proposed to use tow as an absorbent element.

Japanese translations of PCT publication No. 2004-500165 discloses an absorbent element mainly composed of SAP and added with a filament assembly. This absorbent element is a laminate comprising an absorbent layer between about 50 to 95% by weight of SAP and about 5 to 50% by weight of a water-insoluble hydrophilic polymer such as starch and fibers provided between an upper layer and a lower layer. This is a structure, which is folded into a C-shaped cross section and a channel is formed in the center.
JP 2004-65300 A Special Table 2002-524399 (WO99 / 27879) JP-T-2004-500165 (US Pat. No. 6,646,180)

  The tow has a relatively high density, and as it is, the absorption performance and softness are insufficient, so that it needs to be opened.

  However, since the filament aggregate formed by opening the tow is weakly connected with each other, the shape is broken by an external force applied during use, and the initial absorption performance may not be exhibited.

  Moreover, in order to ensure the amount of absorption, it is preferable to hold the superabsorbent polymer particles in the filament aggregate.

  However, the superabsorbent polymer particles move in the filament aggregate during application to the filament aggregate, in the subsequent process, or until it is used by the consumer, and are unevenly distributed in the filament aggregate. May fall off. When these situations occur, the absorption performance is hindered, and the unevenness of the superabsorbent polymer particles that have fallen off from the filament aggregate gives the user a sense of discomfort, which is not preferable.

  Therefore, a main problem of the present invention is to improve the shape retention of the filament aggregate. Another problem is that the shape retention of the filament aggregate is improved and the movement of the superabsorbent polymer particles in the filament aggregate is suppressed, thereby preventing the uneven distribution of the superabsorbent polymer particles and the diffusibility of urine. And improving the absorption rate and preventing gel blocking.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In an absorbent article having an absorber,
The absorbent body is formed of a filament assembly formed by opening a tow composed of continuous long fibers ,
Superabsorbent polymer particles are dispersed throughout the thickness direction in the filament aggregate, and the superabsorbent polymer particles are held in a movable state in the filament aggregate,
The long fibers constituting the filament assembly are continuous in the longitudinal direction of the article,
The filament assembly is only a linear heat-sealed portion along the width direction of the article provided in a plurality at intervals in the front-rear direction of the article as a heat- sealed part formed by partially fusing the filaments together. Have
An absorbent article characterized by the above.

(Function and effect)
The filament aggregate just opened tow is inferior in shape retention. Therefore, in the present invention, the shape retention is to be improved by partially heat-bonding the filaments together and firmly bonding the filaments together. According to the present invention, since the relative position of the filament is fixed at the heat-sealed portion, the shape retention of the filament aggregate is excellent, and the desired absorption performance is reliably exhibited.

Also, in order to secure the amount of absorption, when holding the superabsorbent polymer particles in the filament aggregate, in the filament aggregate just opened tow, the superabsorbent polymer particles move through the filament aggregate, It may be unevenly distributed in the filament assembly or may fall out of the filament assembly. However, in the filament aggregate of the present invention, the movement of the superabsorbent polymer particles is prevented by the heat fusion part. Therefore, compared to a filament assembly in which the tow has just been opened, it is difficult for the highly absorbent polymer to be unevenly distributed or fall out, so that the absorption performance is hindered and it is difficult to give the user a sense of discomfort. .

Further, when the heat fusion part is provided in the form described in this section, the filament aggregate is difficult to expand and contract in the width direction or separate, and the liquid is easily diffused along the heat fusion part. There is.
Further, in the absorbent article in use, the positions of both ends in the front-rear direction are higher than the center in the front-rear direction, so when using the high-absorbency polymer particles, the super-absorbent polymer particles move toward the center in the front-rear direction. easy. On the other hand, when a linear heat fusion portion is provided along the width direction as described in this section, it is possible to prevent the superabsorbent polymer particles from moving in the front-rear direction. It becomes possible to effectively prevent a sense of incongruity.

<Invention of Claim 2>
The absorbent article according to claim 1, wherein the linear heat-sealed portion along the article width direction is continuous from one side of the filament assembly to the other side.

<Invention of Claim 3>
The absorbent article according to claim 1 or 2, wherein a plurality of linear heat-sealed portions along the article width direction are provided at intervals in the front-rear direction over the entire filament assembly.

<Invention of Claim 4 >
The absorptive article according to any one of claims 1 to 3 whose total area of said heat fusion part is 1/6 or more of the area of said absorber.

(Function and effect)
Since the effect tends to be poor when there are few heat fusion parts, the total area is preferably within the range described in this section.

  As described above, according to the present invention, the shape retention of the filament aggregate can be improved, and the movement of the superabsorbent polymer particles in the filament aggregate can be suppressed when the superabsorbent polymer particles are used. Such as being able to do so.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
<Examples of pants-type disposable diapers>
FIG. 1 shows an example of a pants-type disposable diaper. The pants-type disposable diaper 10 includes an exterior sheet 12 on the outer surface (back surface) side and an absorbent main body 20 on the inner surface (front surface) side, and the absorbent main body 20 is fixed to the exterior sheet 12. The absorptive main body 20 is a portion that receives and absorbs and retains body fluids such as urine and loose stool (menstrual blood in a sanitary napkin described later). The exterior sheet 12 is a part for mounting on the wearer.

  The exterior sheet 12 has, for example, an hourglass shape as shown in the figure, and both sides are constricted, and this is a part into which a wearer's leg is put. The absorptive main body 20 can take any shape, but is rectangular in the illustrated form.

  As shown in FIG. 2, the exterior sheet 12 is folded back and forth after the absorbent main body 20 is installed and fixed at a predetermined position, and joined regions 12A on both sides of the front body 12F and the back body 12B of the exterior sheet 12. Are joined by heat fusion or the like. Thereby, a pants-type disposable diaper having a structure shown in FIG. 1 and having a waist opening WO and a pair of leg openings LO is obtained.

  An intermediate width in the longitudinal direction of the absorbent main body 20 shown in the drawing (that is, the vertical direction in FIG. 2, which is also the front-rear direction of the product) is shorter than the width connecting the constricted portions of the exterior sheet 12. This width relationship may be reversed or the same width.

  The exterior sheet 12 is preferably composed of two sheets of water-repellent nonwoven fabric, for example, and an elastic elastic member is interposed between these sheets, and a form that fits the wearer by the contraction force is desirable. As the elastic elastic member, thread rubber or elastic foam band can be used, but it is desirable to use a large number of thread rubbers. In the illustrated embodiment, the rubber threads 12C, 12C,... Are provided continuously in the width direction in the waist region W, provided only on both sides in the lower waist region U, and not provided in the crotch region L. Since the rubber threads 12C, 12C,... Are provided in both the waist region W and the lower waist region U, even if the shrinkage force of the rubber thread 12C itself is weak, the rubber waist 12C hits the wearer in the lower waist region U as a whole. The product fits well to the wearer.

(Absorbent body)
As shown in FIG. 3, the absorbent main body 20 of the embodiment includes a top sheet 30 made of, for example, a nonwoven fabric that allows body fluid to permeate, an intermediate sheet (second sheet) 40, and an absorbent element 50. A body fluid impermeable sheet (also called a back sheet) 70 made of a plastic sheet or the like is provided on the back side of the absorbent body 56. The exterior sheet 12 is provided on the back side of the body fluid impermeable sheet 70. Further, barrier cuffs 60, 60 are provided on both sides.

(Top sheet)
The top sheet 30 has a property of transmitting body fluid. Accordingly, the material of the top sheet 30 is sufficient if it exhibits this body fluid permeability, and examples thereof include a porous or non-porous nonwoven fabric and a porous plastic sheet. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, the spun lace method is a preferable processing method when the flexibility and drape properties are required, and the thermal bond method is the preferable processing method when the bulkiness and softness are required.

  The top sheet 30 may be composed of a single sheet or a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

(Intermediate sheet)
In order to quickly transfer the body fluid that has permeated through the top sheet 30 to the absorbent body, an intermediate sheet 40 that is generally referred to as a “second sheet” that has a higher body fluid permeation rate than the top sheet 30 can be provided. This intermediate sheet not only improves the absorption performance of the absorbent body by quickly transferring the body fluid to the absorbent body, but also prevents the “reversal” phenomenon of the absorbed body fluid from the absorbent body, and the top sheet 30 is always dried. State.

  Examples of the intermediate sheet 40 include the same materials as the top sheet 30, spunlace, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric and a spunbond nonwoven fabric are preferable.

  The intermediate sheet (second sheet) 40 is interposed between the top sheet 30 and the covering sheet 58. As shown in FIG. 5, a configuration in which the intermediate sheet (second sheet) 40 is not provided can also be used.

  The intermediate sheet 40 in the illustrated form is disposed in the center shorter than the width of the absorber 56, but may be provided over the entire width. The length of the intermediate sheet 40 in the longitudinal direction may be the same as the length of the absorbent body 56 or may be within a short length range centered on the region that receives the body fluid. A typical material for the intermediate sheet 40 is a nonwoven fabric having excellent body fluid permeability.

(Absorption element)
The absorbent element 50 includes an absorbent body 56 having an aggregate (filament aggregate) of filaments 52, 52... And a superabsorbent polymer particles 54, 54. And a covering sheet 58 to be wrapped. Further, a holding sheet 80 is provided between the absorbent body 56 and the rear surface side portion (lower portion) of the covering sheet 58.

(Absorber)
The absorber 56 has an aggregate of filaments 52, 52. Preferably, as shown in FIG. 3, superabsorbent polymer particles 54, 54. It is desirable that the superabsorbent polymer particles (SAP particles) are dispersed substantially in the entire thickness direction with respect to the aggregate of the filaments 52, 52. The state of being substantially dispersed throughout the thickness direction is conceptually shown as an enlarged view of the main part of FIG.

  If there is no SAP particle in the upper part, the lower part, and the middle part of the absorber 56, or if there is very little, it cannot be said that the "absorbed throughout the thickness direction". Therefore, “distributed in the entire thickness direction” means “distributed unevenly in the upper, lower, and / or middle portions of the aggregate of filaments, in addition to the form“ uniformly ”distributed in the entire thickness direction. However, it is still included in the form of being dispersed in the upper, lower and middle portions. Further, a form in which some SAP particles do not enter the aggregate of the filaments 52, 52... Remain on the surface, and some SAP particles pass through the aggregate of the filament filaments 52, 52. The form on the sheet 58 and the form on the holding sheet 80 as shown in FIG. 6 are not excluded.

  The aggregate of the filaments 52, 52... Is obtained by opening a tow (fiber bundle) composed of filaments (substantially continuous long fibers). The filament material can be used without particular limitation as long as it can be heat-sealed. 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 spun.

  Examples of cellulose esters that can be suitably used 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 cellulose ester derivatives such as polycaprolactone-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. A particularly preferred cellulose ester is cellulose diacetate.

  The filament 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 filament is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, more preferably 1 to 5 dtex. The filament 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 filament is not particularly limited, and may be any shape such as a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape, etc.) or a hollow shape. . For example, the filament is used in the form of a tow (fiber bundle) formed by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. . The fiber bundle is preferably formed by concentrating about 3,000 to 1,000,000 filaments.

  Since the tow has weak entanglement between filaments, a binder having an action of adhering or fusing the contact portions of the filaments can be used mainly for the purpose of maintaining the shape. Examples of binders include ester plasticizers such as triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin used as the binder is a resin that exhibits an adhesive force when melted and solidified, and includes water-insoluble or hardly water-soluble resins and water-soluble resins. 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.

Since tow can be produced by a known method, it will not be described in detail. Cellulose diacetate tow bales that can be suitably used for the absorbent element 50 are commercially available from Celanese and Daicel Chemical Industries. Cellulose diacetate tow bale has a density of about 0.5 g / cm ³ and a total weight of 400-600 kg.

  From this bale, the tow is peeled off and spread into a wide band so as to have a desired size and bulk. The opening width of the tow is arbitrary, and can be, for example, a width of 100 to 2000 mm, preferably about 100 to 300 mm of the width of the product absorber. Moreover, the density of an absorber can be adjusted by adjusting the degree of tow opening.

  Tow opening methods include, for example, a method in which the tow is spread over a plurality of opening rolls and the tow width is gradually expanded as the tow progresses, and the tow tension (extension) and relaxation (contraction) And the like, and a method of widening and opening using compressed air can be used.

(Superabsorbent polymer particles)
Superabsorbent polymer particles mean to include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used for this type of absorbent article can be used as they are, and those having a particle size of 100 to 1000 μm, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 60 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the body fluid supplied into the absorbent body returns to the outside of the absorbent body tends to occur.

  Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. Thereby, even if it is a case where it is set as a bulky absorber by using tow | toe, the sticky feeling after bodily fluid absorption can be suppressed effectively.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . By setting the basis weight of the polymer to 50 g / m ² or less, it is possible to prevent the lightening effect from becoming difficult to be exhibited by adopting an aggregate of filaments made of tow depending on the weight of the polymer. If it exceeds 350 g / m ² , not only the effect is saturated, but also the above-mentioned crisp and uncomfortable feeling is given due to excess of the superabsorbent polymer particles.

  If necessary, the superabsorbent polymer particles can adjust the spraying density or spraying amount in the plane direction of the absorber 56. For example, the body fluid excretion site can be applied in a larger amount than other sites. When gender differences are taken into account, men can increase the front spray density (amount), while women can increase the center spray density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorber 56 can also be provided.

  If necessary, a plurality of superabsorbent polymer particles having different particle size distributions can be prepared, and can be sequentially dispersed and projected in the thickness direction. For example, by disposing the superabsorbent polymer particle spraying means at intervals in the direction of multiple lines, after spraying and projecting the one with the small particle size distribution first, by spraying and projecting the one with the large particle size distribution, A thing with a small particle size distribution can be distributed to the lower side in the absorber 56, and a thing with a large particle size distribution can be distributed to the upper side. This form is effective for allowing a particle having a small particle size distribution to penetrate deeply into an assembly of filaments.

  The ratio between the superabsorbent polymer particles and the filament aggregate determines the absorption characteristics. As a weight ratio in a planar area of 5 cm × 5 cm in the region directly receiving the body fluid in the absorbent body 56, it is desirable that the superabsorbent polymer particle / filament weight is 1 to 14, particularly 3 to 9.

(Absorber size / weight)
On the other hand, the size of the absorber 56 is preferably such that the planar projection area is 400 cm ² or more and the thickness is 1 to 10 mm, particularly 1 to 5 mm. When the size of the absorber is within this range, it is extremely advantageous to improve the resilience without increasing the weight, thickness and cost. The weight of the absorber is preferably 25 g or less, particularly 10 to 20 g. When the weight of the absorber is within this range, the advantage of not using a dedicated member becomes particularly remarkable.

(Compressive properties of absorber)
The compression resilience RC of the absorbent body 56 is preferably 40 to 60%, particularly 50 to 60%. Thereby, sufficient restoring property can be exhibited with the absorber itself.

Furthermore, it is preferable that the compression energy WC of the absorbent body 56 is 4.0 to 10.0 gf · cm / cm ² , since it can be compressed compactly to the same level as before or during packaging.

  These compression characteristics can be adjusted by adjusting the filament density by opening or the like, selecting the filament material, selecting the type of binder such as a plasticizer, adjusting the degree of processing, or a combination thereof.

  Here, the compression energy (WC) is energy consumption when pressing the central part of the test piece (holding sheet) cut to a length of 200 mm and a width of 50 mm up to 50 g.

This compression energy can be measured with a handy compression tester (KES-G5, manufactured by Kato Tech). The measurement conditions for this tester are: SENS: 2, force meter type: 1 kg, SPEED RANGE: STD, DEF sensitivity: 20, pressurization area: 2 cm ² , capture interval: 0.1 (standard), STROKE SET: 5.0, upper limit load: 50 gf / cm ² .

  On the other hand, the compression resilience (RC) is a parameter representing the recoverability at the time of compression. Therefore, if the recoverability is good, the compression resilience increases. This compression resilience can be measured with a handy compression tester (KES-G5, manufactured by Kato Tech). The measurement conditions for this tester are the same as for the compression energy.

(Enveloping sheet)
As the covering sheet 58, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet having small holes, and the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The basis weight is preferably 8 to ²⁰ g / m ² , particularly 10 to 15 g / m ² .

  As shown in FIG. 3, the covering sheet 58 has a form of covering the entire layer of the aggregates of the filaments 52, 52... And the superabsorbent polymer particles 54, 54. It is also possible to cover only the back and side surfaces. Although not shown, only the upper and side surfaces of the absorbent body 56 are covered with crepe paper or nonwoven fabric, and the lower surface is covered with a body fluid-impermeable sheet such as polyethylene, and the upper surface of the absorbent body 56 is covered with crepe paper or nonwoven fabric. For example, the lower surface may be covered with a body fluid impermeable sheet such as polyethylene (each of these materials becomes a component of the covering sheet). If necessary, the aggregate of the filaments 52, 52, and the superabsorbent polymer particles 54, 54 ... may be sandwiched between two upper and lower sheets or arranged only on the lower surface. This is not a desirable form because it is difficult to prevent movement.

(Holding sheet)
The superabsorbent polymer particles 54 can be interposed between the holding sheet 80 and the absorbent body 56 by spraying or the like. The superabsorbent polymer particles 54 may pass through the aggregate of filaments 52 at the time of dispersion / projection onto the aggregate of filaments 52 or in the subsequent process or until the consumer uses it. The unevenness of the superabsorbent polymer particles that have passed through the filament aggregate gives a crisp and uncomfortable feeling when touched by a hand when used by a consumer. Therefore, a holding sheet 80 having a holding performance of the absorbent polymer is interposed between the absorbent body 56 and the covering sheet 58. The holding sheet 80 reinforces the stiffness that is not sufficient only by the covering sheet 58 such as tissue paper (crepe paper), and reduces or prevents a sense of incongruity when touched by the hand when the consumer uses it.

  In FIG. 6, when the superabsorbent polymer particles 54 are provided below the absorber 56, or when the superabsorbent polymer particles 54 contained in the absorber 56 are used from the manufacture to the consumer. In the stage, the case where the filament 52 is pulled out from the aggregate and collected on the holding sheet 80 is conceptually shown.

  The material of the holding sheet 80 is not particularly limited as long as it has a holding performance of the superabsorbent polymer particles 54. Specifically, for example, non-woven fabric, crimped pulp, low-absorbency cotton fiber (for example, non-degreased cotton fiber, degreased cotton fiber, rayon fiber treated with a water repellent or a hydrophobizing agent, etc.). ), Polyethylene fiber, polyester fiber, acrylic fiber, polypropylene fiber, silk, cotton, hemp, nylon, polyurethane, acetate fiber and the like.

If the holding sheet 80 and the nonwoven fabric, its holding sheet 80, the compression energy 0.01~10.00gfcm / cm ² based on KES test, preferably, at 0.01~1.00gfcm / cm ^2, and compressed The non-woven fabric has a resilience of 10 to 100%, preferably 70 to 100%.

  The reason for providing the holding sheet 80 is to hold, for example, the superabsorbent polymer particles 54 that have fallen down (dropped out) from the absorbent body 56 as described above. Therefore, since the superabsorbent polymer particles 54 that have come out come into contact with the user via the covering sheet 58 and the holding sheet 80, there is no possibility of being transmitted to the user as a sense of incongruity. In particular, the holding function is sufficiently exhibited when the nonwoven fabric has the above-described compression energy and compression resilience.

  Further, since the superabsorbent polymer particles 54 that have escaped are held by the holding sheet 80 and do not move on the covering sheet 58, there is no possibility of uneven distribution of absorption capacity. In particular, in order to prevent the superabsorbent polymer particles 54 from moving on the holding sheet 80, an adhesive hot melt adhesive or the like can be applied on the holding sheet 80 in advance. Moreover, you may make it prevent the superabsorbent polymer particle 54 moving on the holding sheet 80 by making the upper surface (surface which goes to a use surface side) of the holding sheet 80 into a rough surface. Examples of the roughening or fluffing means for this purpose include a non-net surface that is not a net surface during the production of the nonwoven fabric, a marble process, a needle punch process, and a brushing process.

  Even if the holding sheet 80 is provided only below the absorber 56 as shown in FIG. 3 or the like, the holding sheet 80 passes through the side surface of the absorber 56 and extends up to the upper surface of the absorber 56 as shown in FIG. May be. It is also possible to use a plurality of holding sheets 80 in a stacked manner.

  The above example is an example in which the holding sheet 80 is provided between the absorbent body 56 and the back surface side portion of the covering sheet 58, but the holding sheet 80 may be on the back side from the covering sheet 58 (its form) In short, if the holding sheet 80 is provided on the back surface side with respect to the absorbent body 56, it is possible to reduce or not cause a crisp discomfort when touching from the back surface of the product.

(Body fluid impermeable sheet)
The body fluid impermeable sheet 70 simply means a sheet disposed on the back surface side of the absorber 56, and in the present embodiment, is a sheet in which the absorber 56 is interposed between the top sheet 30. Therefore, the material of the main body liquid impermeable sheet is not particularly limited. Specifically, for example, an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet or the like, a nonwoven fabric that substantially ensures liquid impermeability by interposing a waterproof film (in this case, A body fluid impermeable sheet is comprised with a waterproof film and a nonwoven fabric.) Etc. can be illustrated. Of course, in addition to this, materials having liquid impermeability and moisture permeability, which have been used and used in recent years from the viewpoint of preventing stuffiness, can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given.

  The body fluid impervious sheet 70 can be prevented from side leakage of body fluid by extending it to the use surface in a so-called forehead form (not shown). This is prevented by interposing a second body fluid impermeable sheet 72 between the double barrier sheets 64 forming 60. According to this embodiment, since the second body fluid impermeable sheet 72 extends until the barrier cuff 60 stands up, the body fluid diffused laterally through the top sheet 30 and the side of the soft stool between the barrier cuffs 60, 60 There is also an advantage that leakage can be prevented.

(Barrier cuffs)
Barrier cuffs 60, 60 provided on both sides of the product are provided to prevent urine and soft stool that travel laterally along the top sheet 30 and prevent side leakage. It is.

  The illustrated barrier cuff 60 is a doubled water-repellent non-woven sheet, and is formed so as to protrude from the back side of the absorbent body 56 to the lower side of the top sheet 30 and to protrude to the front side. Yes. In order to prevent urine moving in the lateral direction along the top sheet 30, in particular, the side part of the body fluid impermeable sheet 70 is inserted between the double nonwoven fabric sheets, and the barrier cuff 60 protruding from the surface side is provided. It extends halfway.

  The shape of the barrier cuff 60 itself can be designed as appropriate. However, in the example shown in the drawing, an elastic elastic member, for example, a rubber thread 62 is fixed to the tip and middle of the protruding portion of the barrier cuff 60 under stretch, The barrier cuff 60 stands up due to the contraction force in use. As shown in FIG. 3, the base side of the barrier cuff 60 is positioned so that the middle rubber thread 62 is positioned at the center side of the front rubber thread 62, 62 and fixed to the front and rear end portions of the top sheet 30. It rises diagonally toward the center side, and the tip part stands up diagonally outward from the intermediate part.

(Heat fusion)
In the present invention, the filament aggregate is partially heat-sealed, that is, a heat-sealed portion E where the filaments 52 and 52 are heat-sealed and a portion not heat-sealed are formed. The method for heat-sealing is not particularly limited as long as the filaments are heat-sealed. For example, heat sealing, ultrasonic sealing, or heat embossing can be used.

  The heat-sealed portion E may be formed at least in the aggregate of the filaments 52. Accordingly, in the thickness direction, as shown in FIG. 7A, the heat-sealed portion E may be formed only on the absorber 56 without being formed on the top sheet 30 and the intermediate sheet 40. As shown in FIG. 7B, the heat-sealing portion E may be formed so as to reach a part of the absorbent body 56 in the thickness direction or substantially the whole from the surface side of the top sheet 30, and furthermore, the top sheet 30. The heat-sealed portion E may be formed only on the absorber 58 without forming the heat-sealed portion E on the intermediate sheet 40 and the covering sheet 58. Moreover, as shown in FIG.7 (c), the heat sealing | fusion part E can also be formed from the back surface side (opposite side with respect to the top sheet 30 side) of the absorber 56. FIG.

  The aggregate of the filaments 52 formed by opening the tow is inferior in shape retention, but the shape retention can be improved by forming the heat-sealed portion E. Further, the heat fusion part E prevents the movement of the superabsorbent polymer particles 54. Furthermore, since the liquid is easily transmitted through the heat-sealed portion E, an effect of diffusing the liquid along the extending direction of the heat-fused portion E is exhibited. Therefore, it is desirable to determine the arrangement of the heat-sealed portions E in the direction along the surface (surface direction) in consideration of these effects.

  For example, as shown in FIG. 2, a plurality of linear heat-sealed portions E can be provided in parallel along the width direction at intervals in the front-rear direction. In this form, the shape retaining property in the width direction becomes high, and the movement of the superabsorbent polymer particles 54 in the filament aggregate is prevented.

  On the other hand, the heat-sealed portion E of the present invention is preferably provided so as to cover substantially the entire absorber 56, but can also be provided only at a part of the front-rear end portion or the front-rear direction intermediate portion. Further, the total area of the heat-sealed portion E may be determined as appropriate, but in a normal case, it is preferably 1/6 or more, particularly 1/6 to 1/3 of the area of the absorber 56.

  On the other hand, when forming the heat-sealed portion E, if the temperature is too high or the heating time is too long, the material (top sheet 30, intermediate sheet 40, filament 52, etc.) may be cut or perforated. Therefore, it is preferable to determine the temperature and the heating time so that such a situation does not occur.

(Other)
In addition, although not shown in figure, each structural member of the absorptive main body 20 can be mutually fixed by solid, beads, spiral application, etc., such as a hot-melt-adhesive.

(Example of tape-type disposable diapers)
8 and 9 show examples of tape-type disposable diapers. 9 is a view taken along line 9-9 in FIG. 8, but the absorbent main body 20 is illustrated in a slightly exaggerated manner.

  The tape-type disposable diaper 10A has fastening pieces attached to both end portions on the back side of the diaper, has a hook element on a fastening surface of the fastening piece, and a back sheet constituting the back side of the diaper is laminated with a nonwoven fabric. The diaper is configured to be able to engage with a hook element of the fastening piece at an arbitrary position on the surface of the back sheet when the diaper is used as a body.

  The absorbent main body 20 has an absorbent body 56 interposed between the top sheet 30 and the body fluid impermeable sheet 70. The absorbent body 56 is entirely wrapped by a covering sheet 58 made of tissue paper, and has a rectangular shape in plan view. A holding sheet 80 is provided between the absorber 56 and the covering sheet 58.

  Further, an intermediate sheet 40 is interposed between the top sheet 30 and the absorber 56. The body fluid impermeable sheet 70 has a rectangular shape wider than the absorbent body 56, and a back sheet 12A made of an hourglass-shaped non-woven fabric is provided on the outer side thereof.

  The top sheet 30 has a rectangular shape wider than the absorbent body 56, extends slightly outward from the side edge of the absorbent body 56, and is fixed to the body fluid impermeable sheet 70 with a hot melt adhesive or the like.

  Barrier cuffs 60A projecting to the use surface side are formed on both sides of the diaper. The barrier cuffs 60A are formed of a barrier sheet 64 made of a nonwoven fabric substantially continuous in the width direction, and an elastic elastic member such as a thread rubber. And one or a plurality of leg rubber elastic members 62 as elastic elastic members for the leg periphery. Reference numeral 130 denotes a fastening piece using a hook-and-loop fastener.

  The inner surface of the barrier sheet 64 has a fixing start edge at a position separated from the side edge of the top sheet 30, and the outer portion in the width direction extends from the fixing start edge to the extending edge of the body fluid impermeable sheet 70. It is fixed by. The outer surface of the barrier sheet 64 is fixed to the back sheet 12A with a hot melt adhesive or the like on the lower surface thereof. Further, an elastic expansion / contraction member for gasket cuff, for example, thread rubber 66 is provided.

  The starting end of the inner surface of the barrier sheet 64 fixed to the body fluid impermeable sheet 70 forms an upstanding end of the barrier cuff 60A. Around the leg, the inside of the standing end is a free part that is not fixed to the product body, and this free part comes to stand by the contraction force of the rubber thread 62.

  In this example, by using a hook-and-loop fastener as the fastening piece 130, it can be mechanically fastened to the backsheet 12A. Therefore, a so-called target tape can be omitted, and a fastening position by the fastening piece 130 can be freely selected.

  The fastening piece 130 has a base portion of a fastening base material made of plastic, polylaminated nonwoven fabric, paper, or the like joined to the back sheet 12A, for example, with an adhesive, and has a hook element 130A on the tip side. The hook element 130A is bonded to the fastening substrate with an adhesive. The hook element 130A has a large number of engaging pieces on the outer surface side thereof. A temporary fixing adhesive portion 130B is provided on the tip side from the hook element 130A. At the end of the assembly of the product, the temporary fixing adhesive portion 130B is adhered to the barrier sheet 64, thereby preventing the fastening piece 130 from being peeled off at the front end side. At the time of use, it peels off against the adhesive force and brings the front end of the fastening piece 130 to the front body. The fastening base material is exposed at the tip side of the temporary fixing adhesive portion 130B, and is a tab portion.

  A target printing sheet 74 as a design sheet is provided on the inner surface side of the back sheet 12A on the opening side of the front body, and a design that serves as a guide for the position at which the hook element 130A of the fastening piece 130 is fastened is applied. Target printing is performed so that the target can be visually recognized through the back sheet 12A.

  When the diaper is mounted, the diaper is mounted on the body in the shape of a boat, and the contraction force of the rubber thread 62 acts. Therefore, the barrier cuff 60A stands up around the leg by the contraction force of the rubber thread 62.

  The space surrounded by the standing part forms a confined space for urine or soft stool. When urinating into this space, the urine is absorbed into the absorbent body 56 through the top sheet 30, and the rising part of the barrier cuff 60A becomes a barrier for the solid matter of soft stool, and the overpass is prevented. The In the unlikely event that urine leaks laterally over the standing distal side edge of the standing part, side leakage is prevented by the stop function by the flat contact part.

In this embodiment, it is desirable that the barrier sheet 64 forming each standing cuff is not liquid-permeable but substantially liquid-impervious (may be semi-liquid-permeable). Further, the surface sheet (nonwoven fabric laminate) of the present invention may have a property of repelling liquid by silicon treatment or the like. In any case, it is preferable that the barrier sheet 64 and the back sheet 12A are air permeable, and the barrier sheet 64 and the back sheet 12A are sheets having a water pressure resistance of 100 mmH ₂ O or more. Thereby, it becomes air permeable in the width direction side part of a product, and a wearer's stuffiness can be prevented.

  The other points, for example, the material used for each part, etc. are the same as in the case of the above-described pants-type paper diaper, and therefore the description is omitted.

  The present invention is suitable for absorbent articles such as paper diapers, sanitary napkins, incontinence pads, and absorbent pads used in combination with diaper covers.

It is a perspective view of a pants-type disposable diaper. It is an expanded state top view of a pants type disposable diaper. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing of another example. It is sectional drawing of another example. It is sectional drawing of a modification. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. It is an expanded state top view of a tape type disposable diaper. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8 .

  DESCRIPTION OF SYMBOLS 10 ... Pants type disposable diaper, 10A ... Tape type disposable diaper, 12 ... Exterior sheet, 12A ... Back sheet, 20 ... Absorbent main body, 30 ... Top sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 52 ... Filament, 52X ... Veil, 52Y ... Tow, 52Z ... Aggregation of filaments, 54 ... Superabsorbent polymer particles, 56 ... Absorber, 58 ... Cover sheet, 60, 60A ... Barrier cuff, 64 ... Barrier sheet, 70 ... Impermeable to body fluid , 72 ... second body fluid impermeable sheet, 80 ... holding sheet, E ... heat fusion part.

Claims (4)

In an absorbent article having an absorber,
The absorbent body is formed of a filament assembly formed by opening a tow composed of continuous long fibers ,
Superabsorbent polymer particles are dispersed throughout the thickness direction in the filament aggregate, and the superabsorbent polymer particles are held in a movable state in the filament aggregate,
The long fibers constituting the filament assembly are continuous in the longitudinal direction of the article,
The filament assembly is only a linear heat-sealed portion along the width direction of the article provided in a plurality at intervals in the front-rear direction of the article as a heat- sealed part formed by partially fusing the filaments together. Have
An absorbent article characterized by the above. The absorbent article according to claim 1, wherein the linear heat-sealed portion along the article width direction is continuous from one side of the filament aggregate to the other side. The absorbent article according to claim 1 or 2, wherein a plurality of linear heat fusion portions along the article width direction are provided at intervals in the front-rear direction over the entire filament assembly. The absorptive article according to any one of claims 1 to 3 whose total area of said heat fusion part is 1/6 or more of the area of said absorber.

Images