Absorbent articles

Abstract

To improve a function of lateral leakage of an absorbent article.SOLUTION: An absorbent article which has a longitudinal direction and a width direction orthogonal to the longitudinal direction is provided with: an absorber which has a liquid permeable top sheet, a liquid impermeable back sheet, and an absorbent layer disposed between the liquid permeable top sheet and the liquid impermeable back sheet; and a pair of leakage preventing walls extending in the longitudinal direction at both sides in the width direction at a skin surface side of the absorber. Absorbent materials are arranged inside the leakage preventing walls.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to absorbent articles such as incontinence pads and disposable diapers, and particularly to an improvement in the side leakage prevention function of absorbent articles.

Background Art

[0002] Absorbent articles such as incontinence pads and disposable diapers include an absorbent body that absorbs and retains body fluids such as urine and menstrual blood excreted from the body. However, there is a problem that excreted body fluids such as urine and menstrual blood leak from the lateral sides of the absorbent article, and there is a demand for enhancing the side leakage prevention function.

[0003] For example, Patent Document 1 discloses an absorbent article that receives excrement from a wearer, comprising: a backsheet member; and an absorbent sheet member stacked on the backsheet member, an outer edge of which is joined to the backsheet member, so that an opening where the backsheet member is exposed is provided at a position facing the crotch portion of the wearer, wherein the absorbent sheet member includes: an absorbent core disposed on one of the front side and the rear side of the wearer; a liquid-permeable core covering sheet in which the opening is formed and which covers the absorbent core; and a pair of side elastic members disposed on both lateral sides of the opening and applying a contracting force to the core covering sheet in a longitudinal direction perpendicular to the lateral direction; a main pocket extending from the opening in the longitudinal direction is formed between the absorbent core and the backsheet member, a pair of side pockets extending laterally outward from the opening on both lateral sides of the opening are formed between the absorbent sheet member and the backsheet member, the backsheet member includes a water-repellent or liquid-impermeable exterior sheet and a backsheet absorbent disposed inside the exterior sheet, and the backsheet absorbent is provided with a pair of weakened regions that overlap the pair of side elastic members in a plan view and extend linearly or strip-shaped in the longitudinal direction.

Prior Art Literature

Patent Literature

[0004] [Patent Document 1] Japanese Patent Publication No. 2012-200526 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide an absorbent article with enhanced lateral leakage prevention capabilities. [Means for solving the problem]

[0006] The absorbent article of the present invention is an absorbent article having a longitudinal direction and a width direction perpendicular to the longitudinal direction, and is characterized in that it has an absorbent body having a permeable top sheet, a back sheet, and an absorbent layer provided between the permeable top sheet and the back sheet, and on both sides of the width direction on the skin side of the absorbent body a pair of leak-proof walls extending in the longitudinal direction are provided, and an absorbent material is disposed inside the leak-proof walls. [Effects of the Invention]

[0007] According to the present invention, an absorbent article with enhanced lateral leakage prevention capabilities can be obtained. [Brief explanation of the drawing]

[0008] [Figure 1] A plan view showing an example of an absorbent article of the present invention. [Figure 2] A schematic cross-sectional view of a leak-proof wall according to a preferred embodiment of the present invention, shown along line XX in Figure 1. [Figure 3] A schematic cross-sectional view of the VV line in Figure 1 of a leak-proof wall according to a preferred embodiment of the present invention. [Figure 4] A schematic cross-sectional view of a leak-proof wall according to another preferred embodiment of the present invention, shown along line XX in Figure 1. [Figure 5] A schematic cross-sectional view of the VV line in Figure 1 of a leak-proof wall according to another preferred embodiment of the present invention. [Figure 6] A schematic cross-sectional view of a leak-proof wall according to another preferred embodiment of the present invention, shown along line XX in Figure 1. [Figure 7]A schematic cross-sectional view of the VV line in Figure 1 of a leak-proof wall according to another preferred embodiment of the present invention. [Modes for carrying out the invention]

[0009] The absorbent article of the present invention is an absorbent article having a longitudinal direction and a width direction perpendicular to the longitudinal direction, and is characterized in that it has an absorbent body having a permeable top sheet, a back sheet, and an absorbent layer provided between the permeable top sheet and the back sheet, and on both sides of the width direction on the skin side of the absorbent body a pair of leak-proof walls extending in the longitudinal direction are provided, and an absorbent material is disposed inside the leak-proof walls.

[0010] Absorbent articles have a longitudinal direction (front-to-back direction) and a width direction. The longitudinal direction (front-to-back direction) corresponds to the direction extending in the front-to-back direction between the wearer's legs when the absorbent article is worn. The width direction means the direction that lies on the same plane as the absorbent article and is perpendicular to the front-to-back direction, and corresponds to the left-to-right direction of the wearer when the absorbent article is worn. In the width direction of the absorbent article, the side facing the center line in the width direction of the absorbent article is considered the inside, and the opposite side is considered the outside. Also, the direction perpendicular to the plane formed by the width direction and the longitudinal direction (front-to-back direction) is the thickness direction. When the absorbent article is worn by a person, the side facing the wearer's skin is considered the skin side, and the opposite side is considered the non-skin side (outer side).

[0011] The absorbent article of the present invention has an absorbent body comprising a permeable top sheet, a back sheet, and an absorbent layer disposed between the permeable top sheet and the back sheet. The permeable top sheet is disposed on the skin-facing side of the absorbent layer, and the back sheet is disposed on the non-skin-facing (outer) side of the absorbent layer. Excrement that permeates through the top sheet is absorbed and retained by the absorbent layer. The back sheet prevents excrement from leaking out.

[0012] The absorbent article of the present invention has a front region, a crotch region, and a rear region. The front region is the part that is placed against the wearer's abdomen, the rear region is the part that is placed against the wearer's back, and the crotch region is the part that is placed between the wearer's legs.

[0013] The plan view shape of the absorbent article of the present invention is not particularly limited, and examples include rectangles, hourglass shapes, gourd shapes, and shuttlecock shapes. The plan view shape of the absorbent article of the present invention is preferably an hourglass shape with a leg cutout in the crotch area to easily conform to the wearer's groin.

[0014] 1. Permeable top sheet The permeable top sheet is positioned on the wearer's side of the absorbent article and quickly captures the wearer's bodily fluids and moves them to the absorbent layer. The top sheet can be made of a permeable sheet material, such as a nonwoven fabric made of hydrophilic fibers. Examples of nonwoven fabrics used as top sheets include point-bonded nonwoven fabrics, air-through nonwoven fabrics, spunlace nonwoven fabrics, and spunbond nonwoven fabrics. The fibers that form these nonwoven fabrics are usually hydrophobic fibers (e.g., polypropylene, polyethylene, polyester, polyamide) whose surfaces have been treated to make them hydrophilic with a surfactant. Alternatively, a permeable nonwoven fabric made of hydrophilic fibers such as cellulose, rayon, or cotton may be used as the top sheet.

[0015] The planar shape of the top sheet is not particularly limited and can be adjusted according to the shape of the absorber and whether or not there are side sheets. Examples of top sheet shapes include rectangle, hourglass shape, gourd shape, and shuttlecock shape, with hourglass or gourd shape being preferred.

[0016] 2. Back seat The backsheet is disposed on the outermost surface side of the absorbent article. The backsheet may be either a liquid-permeable sheet or a liquid-impermeable sheet, but a liquid-impermeable sheet is preferred. If it is a liquid-impermeable sheet, the effect of preventing body fluid or the like that has reached the backsheet from seeping out to the outer surface side is enhanced. Examples of the liquid-impermeable backsheet include water-repellent or liquid-impermeable nonwoven fabrics formed of hydrophobic fibers (e.g., polypropylene, polyethylene, polyester, polyamide) (e.g., point-bonded nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, SMS (spunbond-meltblown-spunbond) nonwoven fabrics), and water-repellent or liquid-impermeable plastic films. When a plastic film is used for the liquid-impermeable backsheet, a plastic film having moisture permeability (breathability) is preferred from the viewpoint of preventing stuffiness and improving the wearer's comfort, and a nonwoven fabric laminate film in which a nonwoven fabric is laminated on the outer surface is more preferred. In the present invention, liquid impermeability also includes water repellency.

[0017] The planar shape of the backsheet is not particularly limited, and may be adjusted according to the shape of the absorber. The shape of the backsheet is not particularly limited, and examples thereof include rectangle, hourglass shape, gourd shape, battledore shape, etc., with hourglass shape or gourd shape being preferred. 3. Absorbent layer The absorbent layer absorbs and retains body fluids. The absorbent layer preferably contains water-absorbent fibers and / or water-absorbent resin powder as a water-absorbent material.

[0018] The water-absorbing resin powder can be one that has been conventionally used in absorbent articles. The water-absorbing resin powder is not particularly limited, but it is preferable to use a crosslinked polymer having acrylic acid as a component, in which at least a portion of its carboxyl groups have been neutralized. The content of the acrylic acid component constituting the crosslinked polymer is preferably 50% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, preferably 99% by mass or less, and more preferably 97% by mass or less. If the content of the acrylic acid component is within the above range, the resulting water-absorbing resin powder is more likely to exhibit the desired absorption performance.

[0019] The cations that neutralize at least a portion of the carboxyl groups of the crosslinked polymer are not particularly limited, but examples include alkali metal ions such as lithium, sodium, and potassium; and alkaline earth metal ions such as magnesium and calcium. Among these, it is preferable that at least a portion of the carboxyl groups of the crosslinked polymer are neutralized with sodium ions. The neutralization of the carboxyl groups of the crosslinked polymer may be done by neutralizing the carboxyl groups of the crosslinked polymer obtained by polymerization, or by forming the crosslinked polymer using a pre-neutralized monomer.

[0020] The degree of neutralization of the carboxyl groups in the crosslinked polymer is preferably 55 mol% or higher, more preferably 60 mol% or higher, and even more preferably 90 mol% or higher. If the degree of neutralization is too low, the absorption performance of the resulting superabsorbent resin powder may decrease. Furthermore, there is no particular upper limit to the degree of neutralization, and all carboxyl groups may be neutralized. The degree of neutralization can be calculated using the following formula. Degree of neutralization (mol %) = 100 × "Number of moles of neutralized carboxyl groups in the crosslinked polymer" / "Total number of moles of carboxyl groups in the crosslinked polymer (including neutralized and unneutralized groups)"

[0021] The water-absorbing resin powder may contain additives such as preservatives, antifungal agents, antibacterial agents, antioxidants, ultraviolet absorbers, colorants, fragrances, deodorizers, inorganic powders, and organic fibrous materials.

[0022] The basis weight of the water-absorbing resin powder in the absorbent layer is 50 g / m². 2 The above is preferable, 500g / m 2 The following are preferable.

[0023] Examples of the absorbent fibers include pulp fibers, cellulose fibers, rayon, and acetate fibers.

[0024] Examples of the pulp fibers mentioned above include wood pulp made from wood; non-wood pulp made from leaves, grass, straw, etc.; recycled paper pulp made from waste paper, etc.; and recycled pulp recovered from used absorbent materials, etc.

[0025] The basis weight of the pulp fibers in the absorbent layer is 100 g / m². 2 The above is preferable, 500g / m 2 The following are preferable.

[0026] The acetate fiber is a semi-synthetic fiber obtained by esterifying cellulose with acetate. Examples of the acetate fiber include cellulose diacetate fiber (degree of esterification: 2.22 or more and less than 2.76) in which 74% or more and less than 92% of the hydroxyl groups of cellulose are esterified with acetate, and cellulose triacetate fiber (degree of esterification: 2.76 or more) in which 92% or more of the hydroxyl groups of cellulose are esterified with acetate, with cellulose diacetate fiber being preferred. The degree of esterification is the average number of hydroxyl groups substituted with acetyl groups per glucose unit in cellulose.

[0027] The fineness of the acetate fiber (monofilament) is preferably 0.1 dtex or more, more preferably 1.0 dtex or more, even more preferably 1.5 dtex or more, preferably 16 dtex or less, more preferably 10 dtex or less, even more preferably 7.0 dtex or less, and particularly preferably 5.0 dtex or less. If the fineness is 0.1 dtex or more, the cushioning properties of the absorbent layer are further improved, and if it is 16 dtex or less, the texture of the absorbent layer is further improved.

[0028] The cross-sectional shape of the acetate fiber is not particularly limited and may be circular, elliptical, triangular, L-shaped, Y-shaped, X-shaped, W-shaped, octave-shaped, flattened (boomerang-shaped, wavy, cocoon-shaped, rectangular, etc.), polygonal, multi-lobed, hollow, or irregular in shape, such as dogbone-shaped. From the viewpoint of improving dryness after absorbing bodily fluids, circular and elliptical cross-sectional shapes of acetate fibers are preferred.

[0029] Examples of the acetate fiber form include raw cotton (fiber aggregate), multifilament yarn, tow made by plying multifilament yarn, and opened multifilament yarn or tow, with raw cotton being preferred.

[0030] The absorbent layer may contain other fibrous materials. Examples of such fibrous materials include heat-fusible fibers. Heat-fusible fibers are used to enhance shape retention. Specific examples of heat-fusible fibers include polyolefin fibers such as polyethylene and polypropylene, polyester fibers, and composite fibers.

[0031] The absorption layer may be a single layer or a multilayer layer of two or more layers. It is also preferable to provide openings at any location in the absorption layer.

[0032] The thickness of the absorbent layer is preferably 1 mm or more, more preferably 3 mm or more, even more preferably 5 mm or more, preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 8 mm or less. If the thickness of the absorbent layer is 1 mm or more, the wearing comfort is good and the amount of absorption by the absorbent material is improved, and if it is 15 mm or less, discomfort during wear can be further suppressed. The thickness of the absorbent layer is measured using a thickness gauge (TECLOCK Co., Ltd., SM-130) so that the final pressure is 2.2 N or less. The anvil and measuring probe used have a flat contact surface with the object to be measured and a diameter of 10 mm.

[0033] The absorbent layer may be covered with an absorbent layer covering sheet. As the absorbent layer covering sheet, a permeable sheet material such as a nonwoven fabric made of hydrophilic fibers or tissue paper can be used. Among these, tissue paper containing a large amount of paper strength enhancers such as polyvinyl alcohol, carboxymethylcellulose, starch, and polyacrylamide is preferred. Nonwoven fabrics used as absorbent layer covering sheets include, for example, point-bonded nonwoven fabrics, air-through nonwoven fabrics, spunlace nonwoven fabrics, and spunbond nonwoven fabrics, and the hydrophilic fibers that form these nonwoven fabrics are usually cellulose, rayon, cotton, etc.

[0034] 4. Side seats Preferably, a pair of side sheets are arranged on both sides of the skin-facing side of the absorbent. The pair of side sheets are arranged on the skin-facing side of the top sheet, spaced apart in the width direction and along the longitudinal direction (front-to-back direction), at both ends of the skin-facing side of the top sheet. Preferably, the outer ends of the side sheets in the width direction are joined to the back sheet.

[0035] The side sheet can, for example, form a leak-proof wall, and it is preferable that the inner end of the side sheet in the width direction is used to form the leak-proof wall. Since the side sheet is used as a leak-proof wall, it is preferable that it is hydrophobic or water-repellent.

[0036] Examples of side sheets include water-repellent or liquid-impermeable nonwoven fabrics formed from hydrophobic fibers (e.g., polypropylene, polyethylene, polyester, polyamide) (e.g., point-bonded nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, SMS (spunbond-meltblown-spunbond) nonwoven fabrics).

[0037] The shape of the side sheet is not particularly limited, but it is preferable that it has a shape that covers both sides of the back sheet, for example, it is preferable that it has a shape that divides an hourglass-shaped sheet in the vertical direction into two.

[0038] 5.Leakage prevention wall The absorbent material of the present invention is provided with a pair of leak-proof walls extending in the longitudinal direction on both sides in the width direction on the skin-facing side. The leak-proof walls prevent lateral leakage of discharged bodily fluids. An absorbent material is placed inside the leak-proof walls, and the leak-proof function is enhanced as the leak-proof walls absorb the discharged bodily fluids.

[0039] The front and rear ends of the leak-proof wall in the longitudinal direction have fixing portions at both ends that are fixed to the absorbent. Between the fixing portions at both ends, the leak-proof wall has an upright portion that can stand upright on the skin side in the thickness direction.

[0040] The leak-proof wall has a free end that can stand upright on the skin side and an upright end from which the leak-proof wall begins to stand upright. The upright end is fixed to an absorbent (e.g., a top sheet). Preferably, an elastic member extending in the longitudinal direction is positioned in an extended state at the free end. The contraction force of the elastic member promotes the uprighting of the free end toward the skin side.

[0041] The upright end of the leak-proof wall may be located outside or inside the widthwise side edge of the absorbent layer. In the crotch area of ​​the absorbent article, it is preferable that the upright end of the leak-proof wall is located outside the widthwise side edge of the absorbent layer. In the crotch area, having the upright end of the leak-proof wall outside the widthwise side edge of the absorbent layer makes it easier for bodily fluids that reach the upright end to diffuse along the leak-proof wall in the front-to-back direction. Furthermore, in the front and / or rear areas of the absorbent article, it is preferable that the upright end of the leak-proof wall is located inside the widthwise side edge of the absorbent layer. This is because it makes it easier for the absorbent layer to absorb and retain bodily fluids that have diffused in the front-to-back direction.

[0042] Polyurethane rubber yarn, polyurethane rubber film, natural rubber, etc., can be used as the elastic members for the leak-proof wall. Furthermore, it is preferable that the elastic members for the leak-proof wall be fixed with an adhesive such as a hot melt adhesive, and it is more preferable that they be fixed with a rubber-based hot melt adhesive. The number of elastic members for the leak-proof wall, their length in the front-to-back direction, etc., can be adjusted as appropriate. The elongation ratio of the elastic members for the leak-proof wall is preferably 1.2 times or more, more preferably 1.5 times or more, preferably 2.8 times or less, and more preferably 2.4 times or less.

[0043] The leak-proof wall preferably has a two-layer structure. That is, when the leak-proof wall is upright, it has an inner sheet and an outer sheet separated by a free end, with a water-absorbing material between the inner sheet and the outer sheet. The inner sheet is the sheet that faces inward in the width direction (the side where the pair of leak-proof walls face each other) when the leak-proof wall is upright, and the outer sheet is the sheet that faces outward in the width direction.

[0044] The water-absorbing material in the leak-proof wall can be the same as the water-absorbing material used in the absorption layer. Preferably, the leak-proof wall has a fiber aggregate of crushed pulp fibers mixed with water-absorbing resin powder, a continuous acetate fiber aggregate, or a continuous acetate fiber aggregate mixed with water-absorbing resin powder as its water-absorbing material. The water-absorbing material may be fixed to the inner sheet and / or outer sheet with an adhesive.

[0045] The amount of absorbent material contained in one leak-proof wall is preferably 0.5g or more, more preferably 1g or more, even more preferably 2g or more, preferably 10g or less, more preferably 8g or less, and even more preferably 6g or less. If the amount of absorbent material is within the above range, the lateral leakage prevention function can be enhanced without compromising the wearing comfort.

[0046] When using a fiber aggregate made by mixing crushed pulp fibers with water-absorbent resin powder as the water-absorbent material, the amount of crushed pulp fibers contained in one leakproof wall is preferably 0.5 g or more, more preferably 1 g or more, preferably 5 g or less, more preferably 4 g or less, and still preferably 3 g or less. Furthermore, the amount of water-absorbent resin powder contained in one leakproof wall is preferably 0.5 g or more, more preferably 1 g or more, preferably 5 g or less, more preferably 4 g or less, and still preferably 3 g or less.

[0047] The ratio (by mass) of crushed pulp fibers to superabsorbent resin powder (crushed pulp fibers:superabsorbent resin powder) is preferably 3:7 to 7:3, more preferably 4:6 to 6:4, and even more preferably 5:5.

[0048] When using only acetate continuous fiber aggregates as the water-absorbing material, the amount of acetate continuous fiber aggregate contained in one leakproof wall is preferably 0.5 g or more, more preferably 1 g or more, preferably 5 g or less, more preferably 4 g or less, and even more preferably 3 g or less.

[0049] When using an acetate continuous fiber aggregate mixed with water-absorbent resin powder as the water-absorbent material, the amount of acetate continuous fiber aggregate contained in one leakproof wall is preferably 0.5 g or more, more preferably 1 g or more, preferably 5 g or less, more preferably 4 g or less, and still preferably 3 g or less. Furthermore, the amount of water-absorbent resin powder contained in one leakproof wall is preferably 0.5 g or more, more preferably 1 g or more, preferably 5 g or less, more preferably 4 g or less, and still preferably 3 g or less.

[0050] The ratio of the content (mass) of acetate continuous fiber aggregate to water-absorbent resin powder (acetate continuous fiber aggregate: water-absorbent resin powder) is preferably 3:7 to 7:3, more preferably 4:6 to 6:4, and even more preferably 5:5.

[0051] The inner and outer sheets of the leakproof wall may be formed from one type of sheet material or from different sheet materials. Examples of sheet materials include top sheets and side sheets that constitute an absorbent article.

[0052] It is preferable to make the inner sheet of the leak-proof wall hydrophilic and the outer sheet hydrophobic or water-repellent. By making the inner sheet hydrophilic, the discharged bodily fluids are more easily transferred to the inner surface of the leak-proof wall, promoting the absorption of the discharged bodily fluids by the water-absorbing material of the leak-proof wall. Furthermore, by making the outer sheet hydrophobic or water-repellent, it is possible to prevent bodily fluids from seeping out from the leak-proof wall.

[0053] It is also preferable to add slits to the inner sheet of the leak-proof wall. Adding slits makes it easier for bodily fluids to be absorbed by the absorbent material placed inside the leak-proof wall.

[0054] Preferably, the leak-proof wall is composed of side sheets and / or a top sheet. Examples include: an embodiment in which the inner and outer sheets of the leak-proof wall are formed from side sheets; an embodiment in which the inner and outer sheets of the leak-proof wall are formed from a top sheet; and an embodiment in which the inner sheet of the leak-proof wall is formed from a top sheet and the outer sheet is formed from side sheets.

[0055] The leak-proof wall may have a three-layer structure. In this case, either the inner sheet or the outer sheet will have a two-layer structure, while the other will have a single-layer structure. Examples of a three-layer leak-proof wall include a configuration in which the inner and outer sheets are formed from side sheets, and a top sheet is further laminated on the inside of the inner side sheets; and a configuration in which the inner and outer sheets are formed from a top sheet, and a side sheet is further laminated on the outside of the outer top sheet.

[0056] In a preferred embodiment of the present invention, both side edges of the top sheet are folded back towards the skin side at the folding point to form the inner sheet of the leak-proof wall. The widthwise inner edges of the side sheets form the outer sheet of the leak-proof wall.

[0057] It is preferable that each sheet (e.g., the top sheet and the side sheet) is joined at the upright end of the leak-proof wall. The joining may be done with a hot-melt adhesive or by heat bonding, but heat bonding is preferred. Heat bonding can be performed, for example, by applying a heat embossing process to these sheets in the thickness direction.

[0058] The front and rear ends of the leak-proof wall in the longitudinal direction have fixing portions fixed to the absorbent. Preferably, at least one of the widthwise inner edges of the front or rear end is located inside the widthwise side edge of the absorbent layer, and more preferably, both the widthwise inner edges of the front and rear ends are located inside the widthwise side edge of the absorbent layer. That is, preferably, at least one of the front or rear end of the leak-proof wall overlaps the absorbent layer in the thickness direction, and more preferably, both the front and rear ends of the leak-proof wall overlap the absorbent layer in the thickness direction. With this configuration, bodily fluids diffused in the front-rear direction along the inner surface of the leak-proof wall are more easily absorbed and retained by the absorbent layer.

[0059] In the absorbent article of the present invention, it is preferable that leg elastic members extending in the front-to-back direction are arranged in an extended state between the top sheet and the back sheet on both sides. The contraction force of the leg elastic members forms leg gathers, causing the entire absorbent article to take on a bowl shape, which further prevents leakage of bodily fluids such as urine. It is preferable that the leg elastic members are arranged on the outside of both side edges of the absorbent layer in the width direction of the absorbent article.

[0060] The leg elastic members are fixed between the top sheet and the back sheet in the extended state. In this case, the extension ratio of the leg elastic members is preferably 1.2 times or more, more preferably 1.5 times or more, preferably 3.0 times or less, and more preferably 2.5 times or less. The extension ratio in the non-extended state is defined as 1.0 times.

[0061] Polyurethane rubber yarn, polyurethane rubber film, natural rubber, etc., can be used as the elastic members for the legs. Furthermore, it is preferable to fix the elastic members for the legs with an adhesive such as a hot-melt adhesive, and more preferably with a rubber-based hot-melt adhesive. The number of elastic members for the legs, their length in the front-to-back direction, etc., can be adjusted as appropriate.

[0062] When the absorbent article of the present invention has both an elastic leg member and an elastic wall member, it is preferable that the elongation ratio of the leg member is greater than that of the elastic wall member. A larger elongation ratio of the leg member makes it easier for the absorbent article to take on a bowl shape, and the wall member fits more snugly against the user's skin, thus better preventing leakage of bodily fluids such as urine.

[0063] The absorbent articles of the present invention are preferably absorbent articles used on the human body, and include incontinence pads, disposable diapers, sanitary napkins, and disposable auxiliary pads used by attaching them to disposable diapers or sanitary napkins.

[0064] The present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments shown in the drawings. Figure 1 is a plan view of the absorbent article of the present invention. In Figure 1, A is the longitudinal direction (front-to-back direction), and B is the width direction. The longitudinal direction and the width direction are perpendicular. In Figures 2 to 7, C is the thickness direction.

[0065] The absorbent article 1 of the present invention comprises an absorbent body 9 having a permeable top sheet 3, an impermeable back sheet 5, and an absorbent layer 7 provided between the permeable top sheet 3 and the impermeable back sheet 5. A pair of leak-proof walls 11 extending in the longitudinal direction are provided on both sides in the width direction on the skin-facing side of the absorbent body 9, and a water-absorbing material 15 is arranged inside the leak-proof walls.

[0066] The absorbent article 1 has a front region 1a that is placed against the wearer's abdominal side, a rear region 1b that is placed against the wearer's back, and a crotch region 1c that connects the front region 1a and the rear region 1b. The "longitudinal direction (front-to-back direction)" is the direction in which the front region 1a, the crotch region 1c, and the rear region 1b are connected, and the "width direction" is the direction perpendicular to the longitudinal direction (front-to-back direction) and along the surface of the absorbent article. The absorbent article 1 extends in the front-to-back direction from the front region 1a to the rear region 1b, and has a shape that is constricted in the width direction at the crotch region 1c located in between.

[0067] The top sheet 3 is a permeable sheet placed on the skin-facing side of the absorbent article 1. The top sheet 3 extends in a band shape from the front region 1a to the rear region 1b, and its width is smaller than the width of the outer edge of the absorbent article 1.

[0068] The backsheet 5 is positioned on the non-skin side of the absorbent article 1. In plan view, the backsheet 5 has approximately the same shape as the absorbent article 1. That is, the backsheet 5 covers the entire underside of the absorbent article 1.

[0069] The absorbent layer 7 is fixed between the top sheet 3 and the back sheet 5 and has liquid-absorbing and liquid-retaining properties. The absorbent layer 7 is fixed between the top sheet 3 and the back sheet 5 with a hot-melt adhesive (not shown). Also, as shown in Figure 1, the absorbent layer 7 is formed to be slightly smaller than the outer edge of the absorber 9 in a plan view.

[0070] The absorbent body 9 of the present invention is provided with a pair of leak-proof walls 11 extending in the longitudinal direction on both sides in the width direction on the skin-facing side. The front and rear ends of the leak-proof walls 11 in the longitudinal direction have fixing portions 14 at both ends that are fixed to the absorbent body 9. Between the fixing portions 14 at both ends, the leak-proof walls 11 have upright portions that can stand upright on the skin-facing side in the thickness direction. The inner edges in the width direction of the front and rear ends of the leak-proof walls 11 are located inside the side edges in the width direction of the absorbent layer 7.

[0071] An absorbent material 15 is placed inside the leak-proof wall 11. In the embodiment shown in Figure 1, the absorbent material 15 is continuously arranged from the front region 1a to the rear region 1b, but the absorbent material 15 may also be placed only in the crotch region 1c of the leak-proof wall, for example, because lateral leakage of bodily fluids is likely to occur from the crotch region 1c. Alternatively, the absorbent material 15 may be arranged discontinuously from the front region 1a to the rear region 1b.

[0072] The water-absorbing material 15 preferably contains crushed pulp fibers and water-absorbing resin powder.

[0073] Figure 2 is a cross-section of line XX in Figure 1 illustrating a preferred embodiment of the leak-proof wall 11 (hereinafter sometimes referred to as "embodiment A"). The leak-proof wall 11 has a free end 11a that can stand upright on the skin side and an upright end 11b fixed to the absorbent 9 (top sheet 3). An elastic material 17 extending in the longitudinal direction is placed in an extended state on the free end 11a, and the contraction force of the elastic material 17 causes the free end 11a to stand upright on the skin side.

[0074] A pair of side sheets 12 are positioned on both sides of the skin-facing side of the absorbent body 9 to form a leak-proof wall 11. The outer ends of the side sheets 12 in the width direction are joined to the back sheet 5. The inner ends of the side sheets 12 in the width direction form the outer sheet of the leak-proof wall 11.

[0075] As shown in Figure 2, in the crotch area, the upright end 11b of the leak-proof wall 11 is located outside the widthwise side edge of the absorbent layer 7. That is, the leak-proof wall 11 is configured to rise inward from outside the widthwise side edge of the absorbent layer 7. A space is created between the widthwise side edge of the absorbent layer and the upright end 11b of the leak-proof wall 11. Body fluids that flow into this space are absorbed by the absorbent layer 7 and the leak-proof wall 11 while diffusing along the leak-proof wall 11 in the longitudinal direction (front-back direction).

[0076] As shown in Figure 2, in the crotch area, the widthwise side edges of the permeable top sheet 3 extend outward beyond the widthwise side edges of the absorbent layer 7. The permeable top sheet 3 is folded back towards the skin at a folding point 23 located outside the widthwise side edges of the absorbent layer 7.

[0077] The folded permeable top sheet 3a is joined to the top sheet 3 before folding at the joint point 21. The folded permeable top sheet 3a is also joined to the side sheet 12 at the joint point 21. The joining of these sheets is not particularly limited and can be done by means of adhesive or heat bonding, with heat bonding being preferred. By joining by heat bonding, the joining of the folded permeable top sheet 3a to the top sheet 3 before folding and the joining of the folded permeable top sheet 3a to the side sheet 12 can be performed simultaneously.

[0078] The bonding point 21 is preferably located outside the widthwise side edge of the absorption layer. The bonding point 21 is located inside the widthwise fold point 23 of the top sheet.

[0079] The leak-proof wall 11 is composed of a folded top sheet 3a and the widthwise inner end of a side sheet 12. The tip of the widthwise inner end of the side sheet 12 is folded back at the free end 11a and joined to the outer surface of the folded top sheet 3a at the joint point 22. The joining of the sheets at the joint point 22 can be done, for example, by adhesive or by heat bonding. The water-absorbing material 15 is sandwiched between the widthwise inner end of the side sheet 12 and the folded top sheet 3a.

[0080] The folded top sheet 3a constitutes the inner surface (inner sheet) in the width direction of the leak-proof wall, and the inner end in the width direction of the side sheet 12 constitutes the outer surface (outer sheet) in the width direction of the leak-proof wall. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leak-proof wall 11.

[0081] The side sheet 12 is preferably hydrophobic or water-repellent. By being hydrophobic or water-repellent, bodily fluids can be prevented from seeping out of the leak-proof wall.

[0082] Figure 3 is a cross-section of line VV in Figure 1 illustrating a preferred embodiment A of the leak-proof wall 11. As shown in Figure 3, in the rear region, the upright end 11b of the leak-proof wall 11 is located inward from the widthwise side edge of the absorbent layer 7. That is, the leak-proof wall 11 is configured to rise from the upper part of the widthwise side edge of the absorbent layer 7 toward the skin surface. In this case, bodily fluids diffused in the rear region are more easily absorbed and retained by the absorbent layer.

[0083] As shown in Figure 3, in the rear region of the absorbent article, the fold point 23 of the top sheet 3 is located inside the widthwise side edge of the absorbent layer. That is, the permeable top sheet 3 is folded back towards the skin side at the fold point 23 which is inside the widthwise side edge of the absorbent layer. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leakproof wall 11.

[0084] The folded permeable top sheet 3a is joined to the top sheet 3 before folding at the joint point 21. The folded permeable top sheet 3a is also joined to the side sheet at the joint point 21. Preferably, the joint point 21 is located inside the widthwise side edge of the absorption layer 7.

[0085] Figure 4 is a cross-section along line XX of Figure 1 illustrating another preferred embodiment of the leak-proof wall 11 (hereinafter sometimes referred to as "embodiment B"). Referring to Figure 4, a pair of side sheets 12 for forming the leak-proof wall 11 are arranged on both sides of the skin-facing side of the absorber 9. The outer ends of the side sheets 12 in the width direction are joined to the back sheet 5. The inner ends of the side sheets 12 in the width direction constitute the leak-proof wall 11.

[0086] The following explanation will be omitted for components that are common to both Embodiment A and the configuration shown in Figures 2 and 3.

[0087] The leak-proof wall 11 is formed by folding back the inner end in the width direction of the side sheet 12. The leak-proof wall 11 has an inner side sheet 12a and an outer side sheet 12b, with the folding point at the free end 11a as the boundary. The inner side sheet 12a is the sheet that faces the inside in the width direction (the side where the pair of leak-proof walls face each other) when the leak-proof wall 11 is standing upright, and the outer side sheet 12b is the sheet that faces the outside in the width direction.

[0088] The folded-over tip of the inner side sheet 12a is joined to the inner surface of the outer side sheet 12b at a joint point 21. The joint point 21 is located on the outside of the widthwise side edge of the absorbent layer 7. The water-absorbing material 15 is sandwiched between the inner side sheet 12a and the outer side sheet 12b.

[0089] As shown in Figure 4, in the crotch area, the widthwise side edge of the permeable top sheet 3 extends outward beyond the widthwise side edge of the absorbent layer 7. The permeable top sheet 3 is folded back towards the skin side at a fold point 23 located outside the widthwise side edge of the absorbent layer 7. It is preferable that the entire surface of the folded permeable top sheet 3a is joined to the inner side sheet 12a. The entire surface of the folded permeable top sheet 3a can be joined to the inner side sheet 12a, for example, with a hot melt adhesive. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leakproof wall 11. The joining point 21 is located widthwise inward from the fold point 23 of the top sheet.

[0090] At the joint point 21, the tip of the folded inner side sheet 12a is joined to the inner surface of the outer side sheet 12b, the folded permeable top sheet 3a is joined to the inner side sheet 12a, and the folded permeable top sheet 3a is joined to the top sheet 3 before folding. The joining of these sheets is not particularly limited and can be done by means of adhesive or heat bonding, with heat bonding being preferred. By joining by heat bonding, the joining of the inner side sheet 12a and the outer side sheet 12b, the joining of the folded permeable top sheet 3a and the inner side sheet 12a, and the joining of the folded permeable top sheet 3a and the top sheet 3 before folding can be performed simultaneously.

[0091] The side sheet 12 is preferably hydrophobic or water-repellent. The hydrophobic or water-repellent nature of the side sheet 12 prevents leakage of bodily fluids laterally. In this case, the inner side sheet 12a is preferably subjected to hydrophilic treatment with a surfactant or slit processing. Hydrophilic treatment or slit processing promotes the absorption of bodily fluids into the absorbent material 15 within the leak-proof wall 11.

[0092] Figure 5 is a cross-sectional view taken along line VV in Figure 1 illustrating another preferred embodiment B of the leak-proof wall 11. As shown in Figure 5, in the rear region, the upright end 11b of the leak-proof wall 11 is located inward from the widthwise side edge of the absorbent layer 7. That is, the leak-proof wall 11 is configured to rise from the top of the widthwise side edge of the absorbent layer 7 toward the skin surface. In this case, bodily fluids diffused into the rear region are more easily absorbed and retained by the absorbent layer.

[0093] As shown in Figure 5, in the rear region of the absorbent article, the permeable top sheet 3 is folded back towards the skin side at a folding point 23 that is inside the widthwise side edge of the absorbent layer. The folded permeable top sheet 3a is joined to the inner side sheet 12a at a joining point 21. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leakproof wall 11.

[0094] The folded-over tip of the inner side sheet 12a is joined to the inner surface of the outer side sheet 12b at a joint point 21. A water-absorbing material 15 is placed inside the leak-proof wall 11. That is, the water-absorbing material 15 is sandwiched between the inner side sheet 12a and the outer side sheet 12b.

[0095] Figure 6 is a cross-section of line XX in Figure 1 illustrating another preferred embodiment of the leak-proof wall 11 (hereinafter sometimes referred to as "embodiment C"). The leak-proof wall 11 has a free end 11a that can stand upright on the skin side and an upright end 11b fixed to the absorber 9 (top sheet 3). An elastic material 17 extending in the longitudinal direction is placed in an extended state on the free end 11a, and the contraction force of the elastic material 17 causes the free end 11a to stand upright on the skin side.

[0096] The following explanation will omit details of the configurations common to the above embodiments A and B.

[0097] The leak-proof wall 11 is formed by folding back both sides of the top sheet 3. As shown in Figure 6, in the crotch area, the widthwise side edges of the permeable top sheet 3 extend outward beyond the widthwise side edges of the absorbent layer 7. The permeable top sheet 3 is folded back toward the skin side at the folding point 23, which is located outside the widthwise side edges of the absorbent layer 7. The folded top sheet 3a is further folded outward at the free end 11a. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leak-proof wall 11.

[0098] The leak-proof wall 11 has an inner top sheet 3a and an outer top sheet 3b, separated by a folding point at the free end 11a. The inner top sheet 3a is the sheet facing the inside in the width direction (the side where the pair of leak-proof walls face each other) when the leak-proof wall 11 is standing upright, and the outer top sheet 3b is the sheet facing the outside in the width direction. The water-absorbing material 15 is sandwiched between the inner top sheet 3a and the outer top sheet 3b.

[0099] The leading edge of the folded outer top sheet 3b is joined to the skin-facing side of the inner top sheet 3a at a joint point 21. The joint point 21 is located outside the widthwise side edge of the absorption layer 7. The joint point 21 is located inward in the widthwise direction from the folded point 23 of the top sheet.

[0100] Referring to Figure 6, a pair of side sheets 12 are arranged on both sides of the skin-facing side of the absorbent 9 to form a leak-proof wall 11. The outer ends of the side sheets 12 in the width direction are joined to the back sheet 5. The inner ends of the side sheets 12 in the width direction from the joining point 21 are free ends that can stand upright on the skin-facing side and form a leak-proof wall 11. Preferably, the entire surface of the inner ends of the side sheets 12 in the width direction is joined to the outer top sheet 3b. The entire surface of the inner ends of the side sheets 12 in the width direction can be joined to the outer top sheet 3b with, for example, a hot-melt adhesive.

[0101] The side sheet 12 is preferably hydrophobic or water-repellent. The hydrophobic or water-repellent nature of the side sheet 12 prevents leakage of bodily fluids in the lateral direction.

[0102] At the joint point 21, the side sheet 12 is joined to the skin side of the outer top sheet 3b, the leading edge of the outer top sheet 3b is joined to the skin side of the inner top sheet 3a, and the inner top sheet 3a is joined to the skin side of the permeable top sheet 3 before it is folded back. The method of joining these sheets is not particularly limited and includes, for example, joining with an adhesive or joining with heat, with joining with heat being preferred.

[0103] By joining them using heat bonding, the side sheet 12 and the outer top sheet 3b, the outer top sheet 3b and the inner top sheet 3a, and the inner top sheet 3a and the top sheet 3 before it is folded can be performed simultaneously.

[0104] Figure 7 is a cross-sectional view taken along line VV in Figure 1 illustrating another preferred embodiment C of the leak-proof wall 11. As shown in Figure 7, in the rear region, the upright end 11b of the leak-proof wall 11 is located inward from the widthwise side edge of the absorbent layer 7. That is, the leak-proof wall 11 is configured to rise inward from the top of the widthwise side edge of the absorbent layer 7. In this case, bodily fluids diffused into the rear region are more easily absorbed and retained by the absorbent layer.

[0105] As shown in Figure 7, in the rear region of the absorbent article, the permeable top sheet 3 is folded back towards the skin side at a fold point 23 that is inside the widthwise side edge of the absorbent layer. The folded permeable top sheet 3a constitutes the hydrophilic sheet 25 on the inner surface of the leakproof wall 11.

[0106] A water-absorbing material 15 is placed inside the leak-proof wall 11. Specifically, the water-absorbing material 15 is sandwiched between an inner top sheet 3a and an outer top sheet 3b. [Industrial applicability]

[0107] The absorbent material of the present invention can be suitably used, for example, in absorbent articles used to absorb bodily fluids discharged from the human body, and is particularly suitable for use in absorbent articles such as incontinence pads, disposable diapers, and sanitary napkins. [Explanation of Symbols]

[0108] 1: Absorbent material, 3: Top sheet, 5: Back sheet, 7: Absorbent layer, 9: Absorbent material, 11: Leak-proof wall, 12: Side sheet, 15: Water-absorbing material, 17: Elastic material, 21: Joint point, 23: Fold point

Claims

1. An absorbent article having a longitudinal direction and a width direction perpendicular to the longitudinal direction, An absorbent body having a permeable top sheet, a back sheet, and an absorbent layer provided between the top sheet and the back sheet, and a pair of leak-proof walls provided on both sides in the width direction on the skin-facing side of the absorbent body, which extend in the longitudinal direction and rise toward the width-direction centerline of the absorbent article, and an absorbent material is placed inside the leak-proof walls, The leak-proof wall has a free end that can stand upright on the skin side and an upright end that is fixed to the absorbent, and in the front and / or rear regions of the absorbent article, the upright end is located inside the widthwise side edge of the absorbent layer. The leak-proof wall, when in an upright state, has an inner sheet and an outer sheet separated by a free end, with an absorbent material between the inner sheet and the outer sheet, a pair of side sheets arranged on both sides of the skin-facing side of the absorbent, the top sheet is folded back towards the skin-facing side at a folding point, the folded top sheet constitutes the inner sheet of the leak-proof wall, the widthwise inner ends of the side sheets constitute the outer sheet of the leak-proof wall, and the folded top sheet is joined to the top sheet and side sheet before folding at a joining point located widthwise inward from the folding point of the top sheet.

2. The absorbent article according to claim 1, wherein the leak-proof wall has a free end that can stand upright on the skin side and an upright end that is fixed to the absorbent, and in the crotch area of ​​the absorbent article, the upright end is located outside the widthwise side edge of the absorbent layer.

3. The absorbent article according to claim 1 or 2, wherein the inner sheet of the leak-proof wall is hydrophilic, and the outer sheet is hydrophobic or water-repellent.

4. The leak-proof wall is an absorbent article according to any one of claims 1 to 3, comprising absorbent fibers and / or an absorbent resin as an absorbent material.

5. The absorbent article according to any one of claims 1 to 4, wherein at least one of the front or rear end of the leak-proof wall overlaps with the absorbent layer in the thickness direction.

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