JP4346581B2 - Absorbent articles - Google Patents

Description

  The present invention relates to a disposable paper diaper, an absorbent pad, a sanitary napkin, and particularly to an absorbent article with improved soft stool absorption performance.

  Conventionally, absorbent articles have a problem of soft stool absorption performance. Specifically, a situation occurs in which soft stool remains on the surface sheet without passing through the surface sheet, resulting in skin irritation and complicated skin wiping work.

  From this point of view, in order to improve the ability to quickly move loose stool away from the skin (also referred to simply as permeation performance), a perforated sheet is used as the top sheet to facilitate passage of loose stool, and absorption with the top sheet. Techniques for forming a soft stool accommodation space between the body and the body have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

However, there is a demand for further improvement in the permeation performance of soft stool, such as loose stool remaining locally on the topsheet.
Japanese Patent Laid-Open No. 2-65861 JP 2001-276125 A JP 2001-269362 A

  Then, the main subject of this invention is providing the absorbent article which is excellent in the permeation | transmission performance of a surface sheet.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A liquid- permeable surface sheet opposite to the skin, a main body composed of a permeation sheet that transmits excretory fluid and an absorbent element that absorbs and retains excretory fluid, and the surface sheet is fused to the transmission sheet on the upper surface of the main body An absorbent article having a fused part,
The transmissive sheet of the main body is exposed on both sides of the surface sheet, and the fused sheet is formed by subjecting the exposed portion to the permeable sheet of the main body without using the surface sheet. Set up a section,
The absorbent article, wherein the fusion part is provided in at least one position in the width direction at each position in the front-rear direction of the article.

(Function and effect)
A conventional general absorbent article includes a liquid-permeable surface sheet that faces the skin and a main body that receives excretory fluid that has passed through the surface sheet. It is fused by an ultrasonic seal or the like. This fusion part has been conventionally provided over the entire surface sheet, but there was a portion where there is no fusion part anywhere in the width direction in the longitudinal direction of the article. As a result, when the absorbent article was bent along the front-rear direction of the body, wrinkles were generated in the surface sheet depending on the presence or absence of the fused portion, and the transmission performance of the surface sheet was reduced.

The present invention has been made on the basis of such knowledge, and by providing a fusion part at at least one position in the width direction at each position in the front-rear direction of the article, the fusion strength and curing by fusion can be improved before and after the article. Uniform in the direction, the sense of unity between the topsheet and the main body is enhanced, and wrinkles are less likely to occur even if the article is curved along the body longitudinal direction. As a result, the permeation performance originally possessed by the topsheet can be fully exerted, and the permeation performance can be improved as compared with the conventional case.
In addition, when a low-viscosity liquid such as urine is difficult to permeate through the surface sheet, for example, when the surface sheet is made water-repellent in order to suppress diffusion on the surface sheet, the main body is placed on both sides of the surface sheet. When exposed, the excretory fluid can be introduced directly into the main body from both sides without using a surface sheet, which is preferable.
However, in this case, since the fusion target width of the surface sheet is narrowed, if the area ratio of the fusion part in the intermediate part of the article is lowered as described above, the fusion processing conditions in the longitudinal direction of the article (pressure, processing time, etc.) There is a risk that the change of the abruptly becomes difficult and stable and high-quality processing becomes difficult.
Therefore, in the invention described in this section, although the main body portion is exposed on both sides of the surface sheet, a pseudo fusion portion is formed on the exposed portion of the main body portion without reducing the width of the fusion target. It was decided to provide. By doing so, even if the area ratio of the surface sheet fusion part in the intermediate part is lowered to improve the absorbability, fluctuations in the fusion process conditions can be suppressed to a small extent. Therefore, the surface sheet can be subjected to stable and high-quality fusion processing while facilitating the absorption of a low-viscosity liquid such as urine.

<Invention of Claim 2>
The absorbent article according to claim 1, wherein the area ratio of the fused part is lower in the intermediate part between the front and rear end parts of the article.

(Function and effect)
In the present invention, the fusion part is densely arranged in the front-rear direction of the article. However, since the fusion part hardly permeates the excretory fluid, if the area is excessively increased, the permeation performance is hindered. Therefore, as described in this section, it is preferable to configure so that the area ratio of the fused portion is lower in the intermediate portion where the excretory fluid is excreted.

<Invention of Claim 3 >
The topsheet is apertured sheet having a plurality of transmission holes, the fused portion is formed the surface MD direction length than the transmission holes and CD direction length of the sheet is long, claim 1 or 2. The absorbent article according to 2.

(Function and effect)
In the configuration described in this section, even if the position of the fused portion and the position of the transmission hole partially overlap, the fused portion can be processed without fail. As a result, the generation of wrinkles can be reliably prevented, and the transmission performance can be reliably improved. In addition, MD direction and CD direction mean the direction in a fusion process.

  As described above, according to the present invention, there are advantages such as an absorbent article having excellent surface sheet transmission performance.

  Hereinafter, embodiments of the present invention will be described in detail with examples of disposable absorbent pads applied to the use surface of adult pants-type diapers. However, the present invention is applicable to pants-type diapers and tapes for both adults and infants. Needless to say, it can be applied to various absorbent articles such as sanitary napkins and incontinence liners, as well as diapers.

  FIG.1 and FIG.2 has shown the example of the absorption pad which concerns on this invention, and the surface sheet 1 which permeate | transmits the excretion liquid which opposes skin in order from the surface side to the back surface side, and permeation | transmission which permeate | transmits excretion liquid The main body part which consists of the sheet | seat 2 and the absorption element 3 which absorbs and hold | maintains excretion liquid is provided, and the barrier cuffs B and B which stand are provided on the surface side.

In the surface sheet 1, a large number of excretory fluid permeation holes H, H... Are formed at least in a region facing the anus in the embodiment. The surface sheet 1 has an effective opening area of a single permeation hole of 3 to 75 mm ² and an opening area ratio of 10 to 80% in a group of permeation holes of excretion liquid formed at least in a region facing the anus. Some are preferably used. If the open area and the open area ratio are small, the permeability of soft stool solids will be inferior. If the open area is excessively large, the soft stool solids remaining on the surface of the permeable sheet will come into contact with the skin, causing skin irritation and A complicated skin wiping work is required. If the opening area ratio is excessively large, the strength becomes small, which is not preferable.

  For example, when the surface sheet 1 is made water-repellent in order to suppress diffusion on the surface sheet 1, it becomes difficult for a low-viscosity liquid such as urine to penetrate the surface sheet 1. In such a case, as shown in the illustrated example, the width of the top sheet 1 is made smaller than the width between the barrier cuffs BB (the body portion when there is no barrier cuff, the width of the transmission sheet 2 in this case). It is preferable that the main body is exposed (extruded) on both sides of the topsheet 1. As a result, the excretory fluid can be directly introduced into the main body from both side portions without using the top sheet 1.

The material of the top sheet 1 is preferably a non-woven fabric in order to improve the skin feel, but may be a plastic sheet. As the opening shape of the hole H, an appropriate shape such as a round shape, a triangular shape, a quadrangular shape, a rhombus shape, a hexagonal shape or the like can be adopted in addition to the illustrated elliptical shape. Alternatively, a large number can be arranged irregularly. As a nonwoven fabric suitable for the surface sheet 1, an air through nonwoven fabric, a resin bond nonwoven fabric, an airlaid nonwoven fabric, a spunlace nonwoven fabric, a heat roll nonwoven fabric, a spunbond nonwoven fabric and the like can be exemplified. When using a nonwoven fabric for the surface sheet 1, the fineness of the fibers constituting the nonwoven fabric is 2 to 15 dtex, particularly 3 to 10 dtex, especially 4 to 10 dtex, from the point of maintaining a space for absorbing soft stool and increasing permeability. preferable. Moreover, as the fabric weight, 5-45 g / m < ² > is desirable. Furthermore, the topsheet 1 preferably uses water-repellent or hydrophobic fibers in order to suppress diffusion on the topsheet 1.

  The permeable sheet 2 that directly faces the top sheet 1 functions as a layer that quickly transfers the excretory fluid that has passed through the top sheet 2 to the absorbent element 3. The permeable sheet 2 is preferably a sheet mainly composed of water-repellent or hydrophobic fibers, and a non-woven sheet such as an air-through non-woven fabric can also be used. It is desirable that the sheet is opened to form a sheet, in particular, the filament is oriented in the surface direction of the sheet, and further the filament is spirally crimped.

  When a hydrophilic tow such as acetate is opened to form a sheet, the permeability of soft stool is poor. The water-repellent or hydrophobic fibers are excellent in the permeability of soft stool liquid, but, for example, in the case of PET air-through nonwoven fabric, the permeability of the soft stool liquid is not sufficient. On the other hand, for example, when a sheet formed by opening a water-repellent or hydrophobic fiber tow is used as a permeable sheet, the stool liquid content is extremely excellent.

  When the filaments of the permeable sheet 2 are oriented in the surface direction of the sheet, they can be oriented in the width direction of the product (direction perpendicular to the front-rear direction) as well as in the front-rear direction of the product. Orientation in the longitudinal direction of the product has a greater effect of allowing the stool liquid component to permeate and diffuse.

  Examples of water-repellent or hydrophobic filaments that can be suitably used include filaments of PET, PP, PE, and the like, as well as core-sheath filaments made of these.

  The fineness of the filament can be, for example, 1 to 16 denier, preferably 1 to 10 denier, and more preferably about 2 to 8 denier. 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, about 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. In particular, spiral crimped fibers are optimal. The cross-sectional shape of the tow-constituting fibers (filaments) is not particularly limited. It may be. The filament is, for example, in the form of a tow (fiber bundle or filament bundle) formed by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. Can be used. The tow is preferably constructed by concentrating about 3,000 to 1,000,000 filaments.

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. As the binder, various resin adhesives, particularly thermoplastic resins can be used.

The aggregate of filaments can be produced by a known method. As described above, this representative example is a form in which filaments are converged to form a tow, and this tow is opened. The opening width of the tow is arbitrary, and can be, for example, about 100 to 2000 mm, preferably about 150 to 1500 mm. By adjusting the degree of tow opening, the density of the filament aggregate can be adjusted. The filament assembly, fiber density at the time of a thickness of 10mm is 0.0075 g / cm ³ or less, it is suitable as a particularly 0.0060~0.0070g / cm ^3. If the fiber density is excessively high, the advantage of using a fiber assembly made of tow is reduced, and the liquid permeability of soft stool is lowered. Further, the basis weight of the transmissive sheet 2 of the present invention is desirably 10 to 100 g / m ² . The basis weight of the transmissive sheet 2 can be adjusted by selecting a tow serving as a raw fabric or manufacturing conditions thereof.

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

  The absorbent element 3 that directly faces the permeable sheet 2 includes absorbent bodies 3B1 and 3B2 mainly composed of cotton-like pulp that retains excretory liquid, and an upper packaging material 3A that covers the side of the permeable sheet 2 of the absorbent bodies 3B1 and 3B2. And a lower packaging material 3C made of crepe paper such as tissue paper covering the remaining surfaces of the absorbent bodies 3B1 and 3B2. That is, the absorbers 3B1 and 3B2 have a structure in which the absorber 3B is wrapped by the upper packaging material 3A and the lower packaging material 3C.

  As the upper packaging material 3A, an air-through nonwoven fabric, a resin bond nonwoven fabric, an airlaid nonwoven fabric, a spunlace nonwoven fabric, a heat roll nonwoven fabric, a spunbond nonwoven fabric, or the like can be used. Among air-through nonwoven fabrics, it is particularly desirable to use water-repellent or hydrophobic fibers. Examples of the water-repellent or hydrophobic fiber include fibers such as PET, PP, and PE, and fibers having a core-sheath structure using these as materials.

The basis weight of the upper packaging material 3A is preferably 10 to 60 g / m ² . The upper packaging material 3A can be laminated in a single layer or two or more layers, for example, a three-layer structure. When laminated, the basis weight in the laminated state is desirably 10 to 60 g / m ² .

Upper packaging material 3A can be a perforated sheet. In this case, it is desirable from the viewpoint of liquid permeability that the effective opening area of a single transmission hole is 0.5 to 40 mm ² and the opening area ratio is 1 to 80%. In the case of a perforated sheet, in addition to perforating various nonwoven fabrics, a plastic sheet may be perforated.

  As the absorber, it is preferable to use a two-layer absorber in which an upper absorber 3B1 having a narrow width and a lower absorber 3B2 having a wide width are stacked as shown in FIGS. 1 and 2, but as shown in FIG. A single layer absorber 3B can also be used.

  A known cotton-like pulp can be used as the absorbers 3B1 and 3B2, and can be manufactured by stacking pulp fibers by a known method and entanglement treatment with air or water flow. Pulp fibers can be made from cellulose fibers such as chemical pulp and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Softwood pulp with a longer fiber length is better than hardwood pulp. It is preferably used in terms of function and price.

  In the portion surrounded by the upper packaging material 3A and the lower packaging material 3B of the absorbent element 3, high-absorbent polymer particles (SAP) can be encapsulated in order to retain a large amount of liquid.

  Examples of superabsorbent polymers include carboxymethylcellulose, polyacrylic acid and its salts, crosslinked acrylate polymer, starch-acrylic acid graft copolymer, hydrolyzate of starch-acrylonitrile graft copolymer, and polyoxyethylene crosslinked Products, crosslinked products of carboxymethyl cellulose, polyethylene oxide, polyacrylamide, and other partially crosslinked polymers, or a copolymer of isobutylene and maleic acid are 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.

As a method of containing the superabsorbent polymer, a method of spraying a powdery superabsorbent polymer on the outer surface or inside of the absorber 3B1, 3B2, a monomer (which becomes a superabsorbent polymer) in the absorber 3B1, 3B2 A method of polymerizing after impregnation, a method of applying a crosslinking treatment after coating the absorbent bodies 3B1 and 3B2 with an uncrosslinked gel superabsorbent polymer, and the like can be employed. The basis weight of the superabsorbent polymer can be appropriately determined according to the amount of absorption required for the use of the absorbers 3B1 and 3B2. 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 absorbers 3B1 and 3B2, the superabsorbent polymer can be provided in a layered manner on at least one of the front and back sides of the absorbers 3B1 and 3B2. In these cases, the superabsorbent polymer can be adhered to the packaging materials 3A and 3C that wrap the absorbent bodies 3B1 and 3B2 with an adhesive. As the adhesive in this case, the aforementioned thermoplastic resin can be used.

  The back sheet 4 constituting the back side of the absorbent article is a liquid-impervious sheet in the embodiment, and for example, a plastic sheet can be used. The back sheet 4 may have air permeability. The back sheet 4 extends from the side edge of the absorbent element 3 to the side, is folded back to reach the front surface side, forms a flap, and covers the side portion of the top sheet 1.

  A barrier sheet 5 is provided on the side of the top sheet 4, the outer side is fixed to the top sheet 4, the front end side of the inner free part is folded back, and an elastic elastic member 5 a such as thread rubber is provided on that part. Barrier cuffs B and B in which a free part stands up when worn by being fixed under the extension. In the present invention, the presence or absence of a barrier cuff is not limited, but it is desirable to provide a barrier cuff to prevent side leakage of soft stool.

  In addition, between the barrier sheet 5 and the back sheet 4, an elastic elastic member 4 a is fixed along the circumference of the leg under extension, so that the fit of the article around the leg is improved.

  On the other hand, at the time of manufacture, the topsheet 1 is fused to the main body, that is, the permeable sheet 2 when the permeable sheet 2 is provided as shown in the figure, and the absorbent element 3 when it does not. As this fusion method, heat sealing or ultrasonic sealing can be used. The basic principle of these processing methods is the same except for the difference in the heating method, and heating is performed while pressing the convex portions provided on the outer peripheral surface of the processing roll while pressing them on the surface sheet 1, and press-contacting by the convex portions. The part is fused.

  In the present invention, as shown in FIG. 3, the fused portions m, m... Are provided at at least one place in the width direction at each position in the front-rear direction of the article. Such a pattern can be achieved by arranging the convex portions of the processing roll so as not to be interrupted in the outer circumferential direction, in other words, arranging the convex portions so that any one of the convex portions is always fused.

  The pattern of the fusion parts m, m... Can be determined as appropriate. For example, as shown in the figure, a plurality of fusion parts m, m... Having different positions in the front-rear direction and the width direction are arranged in a V shape. It is possible to form a pattern in which a plurality of fused portions are arranged side by side in the front-rear direction. As the shape of the fused portions m, m..., An appropriate shape such as a round shape, a triangle shape, a square shape, a rhombus shape, a hexagon shape, etc. can be adopted in addition to the illustrated oblique ellipse shape. Can be arranged. Note that the fusion part m in the figure indicates the shape of the processing range, and when the surface sheet 1 or the main body part (transmission sheet 2 in the present embodiment) that is the adherend has a hole, the fusion part m is actually fused. It may not be equal to the shape of the joining part to wear.

  Also, whether the front end part FE and rear end part BE of the article and the intermediate part C between them have the same area ratio of the fused parts m, m... (Ratio of the area of all fused parts per unit area). Alternatively, the latter can be increased, but the fusion part, m... Is difficult to permeate the excretory fluid, so that the area ratio of the fusion part m, m. It is preferable to lower the intermediate portion C between the front and rear end portions FE and BE of the article. The area ratio of the fusion parts m, m... Can be adjusted by reducing the number of fusion parts m, m... As shown in the example, and also by reducing the area per one fusion part m. Can be adjusted. The lengths of the front and rear end portions FE and BE and the intermediate portion C of the article can be determined as appropriate. For example, the range of 1 to 100 mm from the front and rear ends is set as the front and rear end portions FE and BE, respectively. The intermediate portion C can be used.

Area in the range of 1 to 300 mm ² per fused portion m one place, in particular it is desirable that in the range of 5 to 30 mm ^2, and the area ratio 0.1 to 20%, especially 0.5 to 10 It is desirable to be within the range of%. When the area ratio of the fusion parts m, m... In the front-rear direction intermediate part C is made lower than the front-rear end parts FE, BE, the area ratio in the front-rear end parts FE, BE is 5-30%, especially 5-20%. It is desirable that the area ratio in the intermediate portion C is 1 to 30%, particularly 1 to 15%.

  When the topsheet 1 is a perforated sheet, the size and the like are selected so that the length in the MD direction and the length in the CD direction of the fused parts m, m... Are longer than the transmission holes H of the topsheet 1. It is preferable to do this. As a result, as shown in FIG. 5, even if the positions of the fusion parts m, m... And the positions of the transmission holes H partially overlap, the fusion parts m, m.

  Furthermore, when the area ratio of the fused part m in the article intermediate part C is made lower than the front and rear end parts FE, BE, and the main body part (the transmissive sheet 2 in the present embodiment) is provided on both sides of the topsheet 1. In the case of exposing, as shown in the illustrated example, the entire exposed surface including the exposed portion 2S of the main body on both sides of the topsheet 1 is subjected to fusion processing, and the topsheet 1 is provided with the fusion portions m, m. In addition to the provision, it is preferable to provide the pseudo-fused portions d, d... On the upper surface of the main body (the transmissive sheet 2 in the present embodiment) without using the topsheet 1. Thereby, as above-mentioned, the surface sheet 1 can be fuse | melted stably and with high quality.

It is a top view in the development state of the example of an absorptive article concerning the present invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. It is a top view which shows only a surface sheet, a main-body part, and these melt | fusion parts. It is sectional drawing of another form. It is a principal part enlarged plan view of a surface sheet.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Surface sheet, H ... Hole of surface sheet, 2 ... Permeable sheet, 3 ... Absorbing element, 3A ... Upper packaging material, 3B ... Absorber, 3C ... Lower packaging material, 4 ... Back surface sheet, 5 ... Barrier sheet , B ... barrier cuff, m ... fusion part, d ... pseudo fusion part.

Claims (3)

A liquid- permeable surface sheet opposite to the skin, a main body composed of a permeation sheet that transmits excretory fluid and an absorbent element that absorbs and retains excretory fluid, and the surface sheet is fused to the transmission sheet on the upper surface of the main body An absorbent article having a fused part,
The transmissive sheet of the main body is exposed on both sides of the surface sheet, and the fused sheet is formed by subjecting the exposed portion to the permeable sheet of the main body without using the surface sheet. Set up a section,
The absorbent article, wherein the fusion part is provided in at least one position in the width direction at each position in the front-rear direction of the article.   The absorbent article according to claim 1, wherein the area ratio of the fused part is lower in the intermediate part between the front and rear end parts of the article. The topsheet is apertured sheet having a plurality of transmission holes, the fused portion is formed the surface MD direction length than the transmission holes and CD direction length of the sheet is long, claim 1 or 2. The absorbent article according to 2.

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