JP6906921B2 - Absorbent article - Google Patents

Description

The present invention relates to an absorbent article, and more particularly to an absorbent article in which a diffusion sheet is provided between a top sheet and an absorber.

Absorbents such as disposable diapers and incontinence pads are equipped with absorbers. The absorber has a water-absorbent resin powder, and the water-absorbent resin powder absorbs and retains body fluids such as urine discharged from the body. In such an absorbent article, it has been proposed to arrange a diffusion sheet in order to increase the absorption rate of the body fluid or the like or to guide the body fluid or the like to the entire absorber.

For example, in Patent Document 1, in an absorbent article in which an absorber is arranged between a front sheet made of a liquid permeable material and a back sheet made of a non-liquid permeable material, the absorbent article is made of a foam and is hydrophilic and substantially. An absorbent article is described in which a sheet-like material that does not swell is arranged between the surface material and the absorber by covering at least a part of the absorber (Patent Document 1 (Patent Document 1). See claim 1, paragraph 0011)).

Patent Document 2 describes a liquid-permeable top sheet, a water-repellent or liquid-impermeable back sheet, an absorber arranged between the top sheet and the back sheet and extending in the front-rear direction, and the absorber. A sheet-like diffusion layer extending in the front-rear direction and a sheet-like diffusion layer arranged between the diffusion layer and the top sheet. An absorbent article characterized by being a member is described (see Patent Document 2 (Claim 1, paragraph 0025)).

Further, in an absorbent article, a technique for preventing the reversion of body fluid absorbed by the absorber has been proposed. For example, Patent Document 3 describes a disposable absorbent article provided with an absorbent mat between a liquid-permeable front sheet and a liquid-impermeable back sheet, wherein the absorbent mat contains water-absorbent resin powder. A sheet-like water-absorbent layer containing and not containing pulp fibers and a fiber assembly layer containing both pulp fibers and water-absorbent resin powder are provided in this order from the surface sheet side, and the fiber assembly layer is a pulp fiber. A disposable absorbent article is described in which a fiber-existing region containing both the pulp fiber and the water-absorbent resin powder and a fiber-free region in which both the pulp fiber and the water-absorbent resin powder are not present are formed adjacent to each other (Patent Reference 3 (see claim 1, paragraph 0027-0029).

Japanese Unexamined Patent Publication No. 2005-152250 Japanese Unexamined Patent Publication No. 2015-167723 Japanese Unexamined Patent Publication No. 2004-329664

Conventionally, an absorbent article in which a diffusion sheet is arranged has been proposed in order to increase the absorption rate of body fluids and the like and to guide body fluids and the like to the entire absorber. In such absorbent articles, the diffusion sheet is often placed between the top sheet and the absorber. However, since not a little body fluid remains on the diffusion sheet, there is a problem that the body fluid remaining on the diffusion sheet is transferred to the top sheet.

The present invention has been made in view of the above circumstances, and in an absorbent article in which a diffusion sheet is provided between a top sheet and an absorber, an absorbent article in which liquid return from the diffusion sheet to the top sheet is suppressed. The purpose is to provide.

The absorbent article of the present invention includes a liquid-permeable top sheet, a non-permeable back sheet, an absorber arranged between the top sheet and the back sheet, and the top sheet and the absorbent body. It has a diffusion sheet arranged between the top sheet and a cover sheet arranged between the top sheet and the diffusion sheet, and the cover sheet has a liquid-permeable first non-woven fabric and a liquid-permeable first non-woven fabric. The SAP height is composed of a second non-woven fabric and a water-absorbent resin powder arranged between the first non-woven fabric and the second non-woven fabric, and the water-absorbent resin powder is encapsulated between the first non-woven fabric and the second non-woven fabric. A plurality of density regions are formed, and at least one SAP low-density region in which the water-absorbent resin powder is substantially not present is formed, and the cover sheet has at least the SAP low-density region and a plurality of SAP high-density regions. , It is characterized in that it is arranged so as to overlap the diffusion sheet in the vertical direction.

The cover sheet total of the water-absorbent resin powder of basis ^{weight, 45g / m 2 ~150g / m} 2 is preferred. The basis weight of the water-absorbent resin powder of SAP high-density regions is the ^{70g / m 2 ~250g / m 2} , it is preferred basis weight of the water-absorbent resin powder of the SAP low-density region is 20 g / m ² or less.

The SAP low-density region and the SAP high-density region are formed so as to extend in the front-rear direction of the cover sheet, and these SAP low-density regions and the SAP high-density region are formed alternately in the width direction of the cover sheet. It is preferable that it is. The cover sheet is preferably arranged so that the SAP low density region overlaps the central portion in the width direction of the diffusion sheet in the thickness direction. The SAP low density region is preferably embossed.

The diffusion sheet preferably contains a foam having pores that are continuous in the plane direction. The absorber has an anterior portion, a crotch portion and a rear portion, the crotch portion is formed narrower than the anterior portion and the rear portion, and the narrowest position of the crotch portion of the absorber is located. It is preferable that the diffusion sheet is not arranged above the crossing line that crosses in the width direction.

According to the present invention, in an absorbent article in which a diffusion sheet is provided between a top sheet and an absorber, an absorbent article in which liquid return from the diffusion sheet to the top sheet is suppressed can be obtained.

Top view of an example of a cover sheet. FIG. 1 is a schematic cross-sectional view taken along the line VV of FIG. Top view of another example of the cover sheet. Top view of another example of the cover sheet. Top view of an example of the absorbent article of the present invention. FIG. 5 is a schematic cross-sectional view taken along the line AA of FIG. FIG. 5 is a schematic cross-sectional view taken along the line BB of FIG. Top view of another example of the absorbent article of the present invention. FIG. 8 is a schematic cross-sectional view taken along the line AA of FIG. FIG. 8 is a schematic cross-sectional view taken along the line BB of FIG.

The absorbent article of the present invention includes a liquid-permeable top sheet, a liquid-impermeable back sheet, an absorber arranged between the top sheet and the back sheet, and the top sheet and the absorbent body. It has a diffusion sheet arranged between the top sheet and a cover sheet arranged between the top sheet and the diffusion sheet. The cover sheet is composed of a liquid-permeable first non-woven fabric, a liquid-permeable second non-woven fabric, and a water-absorbent resin powder arranged between the first non-woven fabric and the second non-woven fabric. A plurality of SAP high-density regions in which the water-absorbent resin powder is contained between the first non-woven fabric and the second non-woven fabric are formed, and at least one SAP low-density region in which the water-absorbent resin powder does not substantially exist is formed. The cover sheet is characterized in that at least the SAP low density region and a plurality of SAP high density regions are arranged so as to overlap the diffusion sheet in the vertical direction.

The SAP high density region is capable of absorbing body fluids. Therefore, when the body fluid remains on the diffusion sheet, the body fluid can be absorbed and retained in the SAP high-density region and can be prevented from being transferred to the top sheet. The SAP low density region is capable of permeating body fluids. Therefore, even when the body fluid that has permeated the top sheet reaches the cover sheet, the body fluid can be permeated into the diffusion sheet through this SAP low density region.

Further, the cover sheet is arranged so that the SAP low-density region and a plurality of SAP high-density regions overlap with the diffusion sheet in the thickness direction. When the body fluid is absorbed, the thickness of the SAP high-density region increases due to the swelling of the water-absorbent resin powder. Therefore, when the SAP high-density region absorbs the body fluid, the SAP low-density region separates from the diffusion sheet. This prevents the body fluid remaining on the diffusion sheet from moving to the SAP low density region. Further, when the SAP low density region is separated from the diffusion sheet as described above, a gap is formed in this portion. The voids thus created facilitate the planar diffusion of the body fluid as it migrates through the SAP low density region to the diffusion sheet.

In the present invention, the anteroposterior direction means a direction extending in the anteroposterior direction of the wearer's crotch when the wearer wears the absorbent article. In the anterior-posterior direction, the position where the wearer is applied to the ventral side is referred to as the front side, and the position where the wearer is applied to the dorsal side is referred to as the posterior side. The width direction means a direction orthogonal to the front-rear direction when the absorbent article is viewed in a plan view. Further, in the present invention, the upper side means the wearer side when the absorbent article is worn, and the lower side means the side opposite to the wearer when the absorbent article is worn, that is, the outside. The direction extending from the upper side to the lower side is referred to as a vertical direction.

1. 1. Diffusion sheet The diffusion sheet is arranged between the top sheet and the absorber. The diffusion sheet rapidly diffuses the body fluid or the like that has reached the diffusion sheet in the front-rear direction and the width direction inside the diffusion sheet.

The plan-view shape of the diffusion sheet is not particularly limited, and examples thereof include a rectangular shape, a trapezoidal shape, a circular shape, and an elliptical shape. The length of the diffusion sheet in the front-rear direction is preferably 20% or more, more preferably 30% or more, preferably 45% or less, and more preferably, when the length of the absorber in the front-rear direction is 100%. Is 40% or less. The width of the diffusion sheet is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, and 70% when the width of the absorber at the position where the diffusion sheet is arranged is 100%. The following is preferable, more preferably 60% or less, still more preferably 50% or less.

The diffusion sheet is arranged so that the entire plan-view shape of the diffusion sheet overlaps the absorber in the vertical direction. By arranging in this way, the body fluid dispersed in the diffusion sheet can be easily taken into the absorber in the end. The outer peripheral edge of the diffusion sheet is preferably located inward of the outer peripheral edge of the absorber. The distance from the outer peripheral edge of the absorber to the outer peripheral edge of the nearest diffusion sheet is preferably 25 mm or more, more preferably 28 mm or more, still more preferably 31 mm or more.

When the absorber has a front part, a crotch part and a rear part, and the crotch part is formed narrower than the front part and the rear part, the narrowest position of the crotch part of the absorber. It is preferable that the diffusion sheet is not arranged above the crossing line that crosses (hereinafter, may be referred to as the "narrowest portion") in the width direction. The narrowest portion is located near the urination port of the user. Further, the narrowest portion is a portion where lateral leakage is most likely to occur because the width of the absorber is narrow. If the diffusion sheet is present in the narrowest portion, the body fluid or the like that has passed through the top sheet is diffused in the width direction by the diffusion sheet, and lateral leakage is likely to occur.

Further, in order to further reduce the occurrence of lateral leakage, it is preferable not to arrange the diffusion sheet in the vicinity of the narrowest portion. Therefore, the region where the diffusion sheet is not arranged is preferably within 65 mm, more preferably within 60 mm, and even more preferably within 55 mm in the front-rear direction from the crossing line.

Only one diffusion sheet may be arranged, or a plurality of diffusion sheets may be arranged. As the arrangement mode of the diffusion sheet, a mode in which the diffusion sheet is arranged only on the rear side of the crossing line of the absorber; a mode in which the diffusion sheet is arranged only on the front side of the crossing line of the absorber; A mode of arranging on both front sides;

When the absorber has a recess as described later, the diffusion sheet is preferably arranged so as to cover the front end portion and / or the rear end portion of the recessed portion of the absorber. That is, it is preferable that the diffusion sheet is arranged so that the body fluid diffused in the concave portion of the absorber in the front-rear direction can be taken into the diffusion sheet at the front end portion / rear end portion of the concave portion. .. By arranging in this way, when the body fluid dispersed in the concave portion of the absorber in the front-rear direction reaches the front end portion and / or the rear end portion of the absorber, it is immediately taken into the diffusion sheet. Then, after being dispersed in the diffusion sheet in the front-rear direction and the width direction, it moves to the absorber below the diffusion sheet. Therefore, the body fluid that has permeated the top sheet is quickly dispersed over a wide area of the absorber through the recesses of the absorber and the diffusion sheet, and is immediately absorbed and retained.

As the arrangement mode of the diffusion sheet, only the diffusion sheet covering the front end portion of the concave portion of the absorber is arranged; only the diffusion sheet covering the rear end portion of the concave portion of the absorber is arranged; An embodiment in which a diffusion sheet covering the front end portion and a diffusion sheet covering the rear end portion of the recess of the absorber are arranged can be mentioned.

A plurality of diffusion sheets for the front end portion may be arranged, but it is preferable to arrange one sheet. Similarly, a plurality of diffusion sheets for the rear end portion may be arranged, but it is preferable to arrange one. The width of the diffusion sheet is preferably 260% or more, more preferably 290% or more, further preferably 320% or more, preferably 460% or less, and more preferably 430, when the width of the recess is 100%. % Or less, more preferably 430% or less.

When the diffusion sheet for the front end portion is arranged, the length of the recess covered by the diffusion sheet for the front end portion is preferably 10% or more, more preferably 10% or more, assuming that the length of the recess in the front-rear direction is 100%. Is 17% or more, more preferably 24% or more, preferably 44% or less, more preferably 39% or less, still more preferably 34% or less. The distance from the front end of the recess of the absorber to the rear end of the diffusion sheet for the front end is preferably 100 mm or more, more preferably 110 mm or more, still more preferably 120 mm or more, and preferably 170 mm or less. , More preferably 160 mm or less, still more preferably 150 mm or less.

When the diffusion sheet for the rear end portion is arranged, the length of the recess covered by the diffusion sheet for the rear end portion is preferably 10% or more, assuming that the length of the recess in the front-rear direction is 100%. It is more preferably 17% or more, further preferably 24% or more, preferably 44% or less, more preferably 39% or less, still more preferably 34% or less. The distance from the rear end of the recess of the absorber to the front end of the diffusion sheet for the rear end is preferably 100 mm or more, more preferably 110 mm or more, still more preferably 120 mm or more, and 170 mm or less. It is preferably 160 mm or less, more preferably 150 mm or less.

The diffusion sheet is not particularly limited as long as it can diffuse body fluid or the like in a plane direction. Examples of the diffusion sheet include foams, three-dimensional three-dimensional knits, long fiber sheets, and non-woven fabrics.

The foam has a large number of pores. In addition, the foam has a large number of pores that are breathable. In the foam, each pore has a through hole with the foam surface or has a through hole between adjacent pores. The shape of each pore is not particularly limited. In addition, the foam may have non-breathable pores. As the foam, a foam having continuous pores in the plane direction is preferable. That is, it is preferable to have through holes between a large number of pores and to have air permeability in the plane direction. Examples of the foam include polyurethane foam.

The apparent density of the polyurethane foam ^{is preferably 100 kg / m 3} or more, more preferably 120 kg / m ³ or more, further preferably 130 kg / m ³ or more, preferably 200 kg / m ³ or less, and more preferably 180 kg / m. ^{It is 3} or less, more preferably 170 kg / m ³ or less. When the apparent density of the polyurethane foam is 100 kg / m ³ or more, the water permeation rate is good, and when it is 200 kg / m ³ or less, the permeation amount is good. The apparent density is the mass per unit volume of a sample that includes both breathable and non-breathable pores. The apparent density of the polyurethane foam is calculated by measuring the volume and mass of a test piece ^{having a volume of 100 cm 3 or more.}

The thickness of the polyurethane foam is preferably 0.5 mm or more, more preferably 1.0 mm or more, further preferably 1.5 mm or more, preferably 5.0 mm or less, more preferably 4.0 mm or less, still more preferably. It is 3.5 mm or less. When the thickness of the polyurethane foam is 0.5 mm or more, the mechanical strength of the polyurethane foam is good, and when it is 5.0 mm or less, the water permeability of the polyurethane foam is good. The thickness of the polyurethane foam is measured using a digital caliper.

The air permeability of the polyurethane foam is preferably 10 L / min or more, more preferably 20 L / min or more, preferably 120 L / min or less, and more preferably 100 L / min or less. If the breathability of the polyurethane foam is 10 L / min or more, stuffiness inside the absorbent article can be prevented. The breathability of the polyurethane foam is measured according to ASTM D3574.

The polyurethane foam is not particularly limited, and examples thereof include those produced by a foaming method, those produced by an extraction method, and those produced by a W / O emulsion method. Further, the polyurethane foam is preferably one that has been subjected to a heat compression treatment in the thickness direction. By the heat compression treatment, each skeleton forming the pore structure in the foam is compressed and deformed in the compression direction, and is deformed as if folded. As a result, in the foam after the heat compression molding, the cell space is denser in the compression direction and the cell skeletons are arranged in the horizontal direction as compared with the state before the heat compression molding. Therefore, the water permeability in the thickness direction is further improved, and the diffusivity in the horizontal direction is also excellent.

The polyurethane foam preferably has a hydrophilic skeleton surface. When the skeleton surface is hydrophilic, the rate of taking body fluid into the diffusion sheet is further increased, and the absorption rate of the absorbent article is further improved.

Whether or not the skeleton surface is hydrophilic is determined by the following method. First, a polyurethane foam (width 10 mm or more, length 10 mm or more) is placed on the edge of the petri dish. At this time, make sure that the polyurethane foam does not bend. Next, using a dropper, 10 droplets (0.05 ml) are gently placed on the polyurethane foam, and the time until these droplets are absorbed by the polyurethane foam is measured. Then, when 8 or more droplets are absorbed within 5 seconds after the droplets are placed, it is judged to be hydrophilic. For the droplets, ion-exchanged water (surface tension (Wilhelmy method, platinum plate, 20 ° C., 65% RH): 70 mN / m or more) is used.

Examples of the polyurethane foam having a hydrophilic surface on the skeleton include those in which the polyurethane itself constituting the skeleton has hydrophilicity; those in which the hydrophobic polyurethane foam is hydrophilized. Examples of the polyurethane itself constituting the skeleton having hydrophilicity include those containing a polyalkylene oxide polyol as a polyol component. Hydrophobic polyurethane foams that have been hydrophilized include those in which at least a part of the skeleton surface of the hydrophobic polyurethane foam is coated with a surfactant, and those in which the hydrophobic polyurethane foam is treated with a reactive gas such as ethylene oxide. Examples thereof include those treated with, and having a hydrophilic group added to the surface of the pores.

Examples of the surfactant include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Examples of the anionic surfactant include carboxylates, sulfonates, sulfates and the like. Examples of the nonionic surfactant include an ester-type nonionic surfactant, an ether-type nonionic surfactant, and an ester-ether-type nonionic surfactant.

Examples of the three-dimensional three-dimensional knit include a three-dimensional three-dimensional knit of resin fibers (for example, Fusion (registered trademark) manufactured by Asahi Kasei Fibers Co., Ltd.).

Examples of the long fiber sheet include long fiber sheets containing cellulose acetate long fibers. Cellulose acetate fiber has a cellulose skeleton and has a high affinity with body fluids, so that the rate of uptake and diffusion of body fluids is high. In addition, the hydroxyl group of the cellulose skeleton is acetylated, and it does not substantially absorb water, and its affinity with body fluids is not too high. Therefore, the body fluid diffused by the cellulose acetate fibers is easily absorbed by the water absorber in the end.

Examples of the non-woven fabric include spunbonded non-woven fabrics.

2. Cover sheet The absorbent article has a cover sheet between the top sheet and the diffusion sheet. By having the cover sheet, the body fluid remaining on the diffusion sheet is suppressed from being transferred to the top sheet. As a result, the dry feeling after absorption of the body fluid becomes better. The plan view shape of the cover sheet is larger than the plan view shape of the diffusion sheet, and it is preferable that the cover sheet is arranged so as to cover the entire diffusion sheet. The plan view shape of the cover sheet is not particularly limited, and examples thereof include a rectangular shape, a trapezoidal shape, a circular shape, and an elliptical shape.

The cover sheet is composed of a liquid-permeable first non-woven fabric, a liquid-permeable second non-woven fabric, and a water-absorbent resin powder arranged between the first non-woven fabric and the second non-woven fabric. Then, on the cover sheet, a plurality of SAP high-density regions in which the water-absorbent resin powder is contained between the first non-woven fabric and the second non-woven fabric are formed, and the SAP in which the water-absorbent resin powder is substantially not present is formed. At least one low density region is formed.

The SAP high density region is capable of absorbing body fluids. Therefore, when the body fluid remains on the diffusion sheet, the body fluid can be absorbed and retained in the SAP high-density region and can be prevented from being transferred to the top sheet. The SAP low density region is capable of permeating body fluids. Therefore, even when the body fluid that has permeated the top sheet reaches the cover sheet, the body fluid can be permeated into the diffusion sheet through this SAP low density region.

Further, the cover sheet is arranged so that at least the SAP low density region and a plurality of SAP high density regions overlap the diffusion sheet in the vertical direction. When the body fluid is absorbed, the thickness of the SAP high-density region increases due to the swelling of the water-absorbent resin powder. Therefore, when the SAP high-density region absorbs the body fluid, the SAP low-density region separates from the diffusion sheet. This prevents the body fluid remaining on the diffusion sheet from moving to the SAP low density region. Further, when the SAP low density region is separated from the diffusion sheet as described above, a gap is formed in this portion. The voids thus created facilitate the planar diffusion of the body fluid as it migrates through the SAP low density region to the diffusion sheet.

The texture of the water-absorbent resin powder of the entire cover sheet ^{is preferably 45 g / m 2} or more, more preferably 60 g / m ² or more, further preferably 70 g / m ² or more, and more ^{preferably 150 g / m 2} or less. It is preferably 130 g / m ² or less, and more preferably 120 g / m ² or less. If the texture of the water-absorbent resin powder of the entire cover sheet is 45 g / m ² or more, the body fluid leaked from the diffusion sheet can be sufficiently absorbed, and if it is 150 g / m ² or less, the top sheet is transferred to the cover sheet. The body fluid that has migrated to the above can be permeated through the diffusion sheet or the absorber without any problem.

The texture of the water-absorbent resin powder in the SAP high-density region ^{is preferably 70 g / m 2} or more, more preferably 120 g / m ² or more, still more preferably 150 g / m ² or more, and ^{preferably 250 g / m 2} or less. It is more preferably 220 g / m ² or less, and even more preferably 200 g / m ² or less. If the texture of the water-absorbent resin powder in the SAP high-density region is 70 g / m ² or more, permeation of body fluid through the SAP high-density region can be prevented ^{, and if it is 250 g / m 2} or less, it is included between the non-woven fabrics. The absorbed absorbent resin powder can be sufficiently expanded.

The basis weight of the water-absorbent resin powder in the SAP low-density region ^{is preferably 20 g / m 2} or less, more preferably 15 g / m ² or less, and further preferably 10 g / m ² or less. If the texture of the water-absorbent resin powder in the SAP low-density region is 20 g / m ² or less, the first non-woven fabric and the second non-woven fabric can be bonded in the SAP low-density region, and from the top sheet to the cover sheet. The speed at which the transferred body fluid permeates through the diffusion sheet or absorber increases. The lower limit of the basis weight of the water-absorbent resin powder in the SAP low-density region is 0 g / m ² .

The water-absorbent resin powder in the SAP high-density region is preferably fixed to the first non-woven fabric and / or the second non-woven fabric with an adhesive. Examples of the adhesive include natural rubber-based, butyl rubber-based, rubber-based such as polyisoprene, styrene-based elastomers such as SIS, SBS, SIBS, SEBS, and SEPS, ethylene-vinyl acetate copolymer (EVA), polyester, and acrylic-based adhesives. , Hot melt type adhesives such as polyolefin-based elastomers.

In the SAP low density region, the first non-woven fabric and the second non-woven fabric are joined. By joining the first non-woven fabric and the second non-woven fabric, the water-absorbent resin powder existing in the SAP high-density region is prevented from moving to the SAP low-density region. The method of bonding the first non-woven fabric and the second non-woven fabric is not particularly limited, and examples thereof include an adhesive, heat sealing, and ultrasonic bonding. Further, it is preferable that the SAP low density region is embossed. When the embossing is applied, a part of the non-woven fabric in the SAP low density region becomes very thin, and this part makes it easier for the body fluid to permeate.

The SAP low-density region and the SAP high-density region are formed so as to extend in the front-rear direction of the cover sheet, and these SAP low-density regions and the SAP high-density region are formed alternately in the width direction of the cover sheet. It is preferable that it is. With this configuration, the gap is formed in the front-rear direction of the cover sheet. Therefore, the diffusion rate of the body fluid in the anteroposterior direction can be further increased.

The width of each SAP high-density region formed so as to extend in the front-rear direction is preferably 8 mm or more, more preferably 10 mm or more, further preferably 12 mm or more, preferably 22 mm or less, more preferably 20 mm or less, and further. It is preferably 18 mm or less. The width of each SAP low-density region formed so as to extend in the front-rear direction is preferably 2 mm or more, more preferably 2.5 mm or more, further preferably 3 mm or more, preferably 10 mm or less, and more preferably 8 mm or less. , More preferably 7 mm or less.

The cover sheet preferably has a SAP low density region formed so as to extend in the front-rear direction at the center in the width direction. In this case, the width of the SAP low density region formed in the center in the width direction is preferably 18 mm or more, more preferably 20 mm or more, further preferably 22 mm or more, preferably 31 mm or less, more preferably 29 mm or less, still more preferably. Is 27 mm or less.

The cover sheet is preferably arranged so that the SAP low density region (preferably the SAP low density region formed in the central portion in the width direction) overlaps the central portion in the width direction of the diffusion sheet in the vertical direction. ..

The cover sheet is preferably arranged so as to cover the entire diffusion sheet. The length of the cover sheet in the front-rear direction is preferably equal to or greater than the length of the absorber in the front-rear direction. Further, the length of the cover sheet in the front-rear direction may be substantially the same as the length of the entire absorbent article in the front-rear direction.

When the absorber has a front part, a crotch part and a rear part, and the crotch part is formed narrower than the front part and the rear part, the narrowest position of the crotch part of the absorber. It is preferable that the cover sheet is not arranged above the crossing line that crosses in the width direction. Further, in order to further reduce the occurrence of lateral leakage, it is preferable not to arrange the cover sheet in the vicinity of the narrowest portion. Therefore, the area where the cover sheet is not arranged is preferably within 65 mm in the front-rear direction from the crossing line, more preferably within 60 mm, and further preferably within 55 mm.

The materials of the first non-woven fabric and the second non-woven fabric are not particularly limited as long as they are liquid-permeable non-woven fabrics. For example, a non-woven fabric formed from hydrophilic fibers such as cellulose, rayon, and cotton; a non-woven fabric formed from hydrophobic fibers such as polyolefin (polypropylene, polyethylene), polyester, and polyamide, and the surface of the hydrophobic fibers is surface active. Examples thereof include non-woven fabrics that have been hydrophilized by the agent. Examples of the water-absorbent resin powder include water-absorbent resin powders such as polyacrylic acid-based, polyaspartic acid-based, cellulosic-based, and starch / acrylonitrile-based.

3. 3. Top sheet The top sheet is a sheet located on the wearer side when the absorbent article is worn. The material of the top sheet is not particularly limited as long as it is liquid permeable. The plan-view shape of the top sheet is not particularly limited, and may be adjusted according to the shape of the absorber and the presence or absence of the side sheet.

Examples of the top sheet include hydrophilic non-woven fabrics, woven fabrics, and knitted fabrics. The hydrophilic non-woven fabric is a non-woven fabric formed of hydrophilic fibers such as cellulose, rayon, and cotton; and a non-woven fabric formed of hydrophobic fibers such as polyolefin (polypropylene, polyethylene), polyester, and polyamide, and is hydrophobic. Examples thereof include a non-woven fabric in which the surface of the fiber is hydrophilized by a surfactant.

4. Back seat The back seat is a seat located on the opposite side of the wearer, that is, on the outside when the absorbent article is worn. The material of the back sheet is not particularly limited as long as it is impermeable. In the present invention, the impermeable property also includes water repellency. The plan-view shape of the back sheet is not particularly limited, and may be adjusted according to the shape of the absorber.

Examples of the back sheet include a hydrophobic non-woven fabric, a plastic film, and a laminate of the plastic film and the non-woven fabric. Examples of the hydrophobic non-woven fabric include non-woven fabrics formed of hydrophobic fibers such as polyolefin (polypropylene, polyethylene), polyester, and polyamide. Examples of the plastic film include a film formed of a resin such as polyolefin (polypropylene, polyethylene), polyester, or polyamide. The non-woven fabric laminated on the plastic film may be either hydrophilic or hydrophobic.

5. Absorber The absorber is placed between the top sheet and the back sheet. The absorber absorbs and retains body fluids. The absorber has an anterior, crotch and posterior part. The front portion is a portion located on the ventral side of the wearer when wearing the absorbent article. The rear portion is a portion located on the back side of the wearer when wearing the absorbent article. The crotch portion is located between the front portion and the rear portion, and is a portion located in the inseam of the wearer when the absorbent article is worn.

The plan-view shape of the absorber is not particularly limited. It is preferable that the crotch portion of the absorber is formed to be narrower than that of the front portion and the rear portion. When the width of the widest position of the front part is 100%, the width of the narrowest position of the crotch part is preferably 45% or more, more preferably 48% or more, still more preferably 50% or more. It is preferably 60% or less, more preferably 57% or less, still more preferably 55% or less. The width of the narrowest portion is preferably 99 mm or more, more preferably 105 mm or more, further preferably 110 mm or more, preferably 132 mm or less, more preferably 125 mm or less, still more preferably 121 mm or less. The plan view shape of the absorber is preferably an hourglass type or a gourd type.

The length of the absorber in the front-rear direction is preferably 480 mm or more, more preferably 500 mm or more, further preferably 520 mm or more, preferably 600 mm or less, more preferably 580 mm or less, still more preferably 560 mm or less. The maximum width of the front part and the rear part of the absorber is preferably 190 mm or more, more preferably 200 mm or more, further preferably 210 mm or more, preferably 250 mm or less, more preferably 240 mm or less, still more preferably 230 mm or less. ..

The absorber preferably has a recess extending in the front-rear direction on the side surface of the top sheet. By having the recess, the body fluid that has reached the absorber can be immediately diffused in the recess in the front-rear direction. The plan view shape of the concave portion is preferably a rectangular shape or a rectangular shape with rounded corners.

The depth of the recess is not particularly limited, but when the thickness of the absorber is 100%, the depth of the recess (distance from the surface of the absorber to the bottom of the recess) is preferably 35% or more, more preferably 35% or more. It is 40% or more, more preferably 45% or more. The recess may penetrate the absorber in the thickness direction. That is, the recess includes an opening (through hole).

The length of the recess in the front-rear direction is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, and 60% or less, when the length in the front-rear direction of the absorber is 100%. Is preferable, more preferably 55% or less, still more preferably 50% or less.

At least one recess may be provided. Although a plurality of recesses may be arranged side by side in the width direction, it is preferable to provide one recess substantially in the center of the absorber in the width direction. The width of the recess is preferably 13% or more, more preferably 15% or more, further preferably 17% or more, preferably 24% or less, more preferably 24% or less, when the width of the narrowest portion is 100%. It is 22% or less, more preferably 20% or less. The width of the recess is preferably 15 mm or more, more preferably 17 mm or more, further preferably 19 mm or more, preferably 28 mm or less, more preferably 25 mm or less, still more preferably 23 mm or less.

The recess is preferably provided so as to intersect a crossing line that crosses the narrowest portion of the crotch portion in the width direction. The narrowest portion is located near the urination port of the user. Further, the narrowest portion is a portion where lateral leakage is most likely to occur because the width of the absorber is narrow. By providing the concave portion in the narrowest portion, the body fluid that has reached the narrowest portion can be immediately diffused in the front-rear direction, so that lateral leakage in the crotch portion can be suppressed. When the absorber has a plurality of narrowest portions or when the narrowest portion is formed so as to have a certain length in the front-rear direction, the narrowest portion closest to the central portion in the front-rear direction of the absorber. A crossing line will be drawn on the part.

The position where the recess and the crossing line intersect is not particularly limited, but when the front end of the recess is 0% and the rear end is 100%, the intersection with the crossing is located at 30% to 70%. It is more preferably 40% to 60%, still more preferably 45% to 55%. If the intersection with the crossing line is provided so as to be located at 30% to 70% of the recess, the body fluid that has reached the narrowest portion can be evenly dispersed in the front portion and the rear portion of the absorber.

The recess is in the range of 20% to 35% (more preferably) when the front end of the absorber is 0% and the rear end is 100% as a relative position of the absorber in the front-rear direction. Is located in the range of 25% to 30%), and the rear end portion of the recess is preferably located in the range of 60% to 75% (more preferably in the range of 65% to 70%).

The absorber may have only one layer or two or more layers. When the absorber has two or more layers, a recess is provided in the absorber located closest to the top sheet side. When the recess is used as an opening, it is preferable that the absorber has two layers. Further, it is preferable that another absorber is arranged below the opening.

The absorber is not particularly limited as long as it contains an absorbent material capable of absorbing excrement such as urine. Examples of the absorber include a molded body obtained by molding an absorbent material into a predetermined shape, and a material obtained by covering the absorbent material with a sheet member such as a paper sheet (for example, tissue paper or thin paper) or a liquid-permeable non-woven fabric sheet. Can be used.

Examples of the absorbent material include hydrophilic fibers such as crushed pulp fibers and cellulose fibers, and water-absorbent resins such as polyacrylic acid-based, polyaspartic acid-based, cellulose-based, and starch / acrylonitrile-based. Further, the water-absorbent material may include polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as polyethylene terephthalate, and heat-sealing fibers such as polyamide fibers. These heat-sealing fibers may be hydrophilized with a surfactant or the like in order to enhance the affinity with body fluids such as urine.

The absorbent material preferably contains hydrophilic fibers from the viewpoint of increasing the absorption rate of urine and the like. Further, from the viewpoint of increasing the absorption capacity, the absorbent material preferably contains a water-absorbent resin. As the absorbent material, for example, it is preferable to use a material obtained by mixing or spraying a water-absorbent resin with an aggregate of hydrophilic fibers.

6. Absorbent Articles Examples of the absorbent articles of the present invention include incontinence pads, disposable diapers, sanitary napkins, disposable diaper bodies, disposable auxiliary pads attached to sanitary napkins, and the like.

If the absorbent article is an incontinence pad, sanitary napkin or disposable auxiliary pad, for example, an absorbent and diffusing sheet is placed between the permeable topsheet and the impermeable backsheet. .. Examples of the shape of the incontinence pad, sanitary napkin or disposable auxiliary pad include an hourglass type and a gourd type. Further, if necessary, liquid-impermeable side sheets may be provided on both sides of the liquid-permeable top sheet in the width direction. The side sheets are joined to the upper surfaces of both sides in the width direction of the top sheet, and the side sheets inward in the width direction from the joining point form a pair of rising flaps along both side edges of the absorber.

When the absorbent article is a disposable diaper, the disposable diaper is, for example, a tape-type disposable diaper in which a pair of fastening members are provided on the left and right sides of the back or front abdomen, and the fastening members form a pants shape when worn. Diapers; Pants-type disposable diapers in which a waist opening and a pair of leg openings are formed by joining the anterior abdomen and the back back; and the like.

When the absorbent article is a disposable diaper, the disposable diaper forms, for example, a diaper body consisting of a laminate of inner and outer sheets consisting of anterior abdomen and back and a crotch located between them. , The water absorber and the diffusion sheet may be arranged on the crotch portion. Further, a disposable diaper is composed of, for example, a laminated body in which an absorber and a diffusion sheet are arranged between a top sheet and a back sheet, and the laminated body is located between the anterior abdomen and the back back and the crotch portion located between them. And may have. The inner sheet is preferably hydrophilic or water repellent, and the outer sheet is preferably water repellent.

It is preferable that the disposable diaper is provided with rising flaps along both side edges. By providing the rising flap, it is possible to prevent lateral leakage of body fluid. The rising flaps may be formed by raising the inner ends of the side sheets provided on both sides of the top sheet in the width direction. The rising flap and side sheet are preferably water repellent.

7. Specific Examples Next, the absorbent article of the present invention will be described with reference to the drawings. The cover sheet used in the present invention will be described with reference to FIGS. 1 to 4. The absorbent article of the present invention will be described with reference to FIGS. 5 to 10 by taking a disposable auxiliary pad as an example. In the figure, the arrow x is defined as the width direction, and the arrow y is defined as the front-back direction. Further, the direction on the plane formed by the arrows x and y is defined as the plane direction. Further, the vertical direction represents the vertical direction z with respect to the surface formed by the arrows x and y.

7-1. Cover sheet FIG. 1 is a plan view of an example of a cover sheet. FIG. 2 is a schematic cross-sectional view taken along the line VV of FIG. The cover sheet 20 is composed of a liquid-permeable first non-woven fabric 21, a liquid-permeable second non-woven fabric 22, and a water-absorbent resin powder 23 arranged between the first non-woven fabric 21 and the second non-woven fabric 22. Has been done. The cover sheet 20 is formed with a plurality of SAP high-density regions 24 in which the water-absorbent resin powder 23 is encapsulated between the first non-woven fabric 21 and the second non-woven fabric 22, and the water-absorbent resin powder 23 is formed. A plurality of SAP low density regions 25 that are substantially nonexistent are formed. In FIG. 1, the shaded area is the SAP high-density region 24.

The SAP low-density region 25 and the SAP high-density region 24 are formed so as to extend in the front-rear direction y of the cover sheet 20, and these SAP low-density region 25 and the SAP high-density region 24 are the cover sheet. It is formed alternately in the width direction x. Further, the cover sheet 20 has a SAP low density region 25a formed so as to extend in the front-rear direction at the center in the width direction.

In FIGS. 1 and 2, four SAP high-density regions 24 and five SAP low-density regions 25 are formed, but the number is not limited thereto. In FIG. 2, the water-absorbent resin powder 23 is not arranged in the SAP low-density region 25, but some water-absorbent resin powder 23 is present in the SAP low-density region 25 as long as the effect of the present invention is not impaired. You may. In FIG. 1, the SAP high-density region 24 is formed so as to be continuous in the front-rear direction of the cover sheet 20, but may be formed intermittently.

3 and 4 show a plan view of another example of the cover sheet. In the following description, the parts that overlap with the embodiments of FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. In FIGS. 3 and 4, the shaded area is the SAP high-density region 24.

In the cover sheet shown in FIG. 3, the SAP low density region 25 and the SAP high density region 24 are formed so as to extend in the width direction x of the cover sheet 20, and the SAP low density region 25 and the SAP height are formed. Density regions 24 are alternately formed in the front-rear direction y of the cover sheet. In FIG. 3, six SAP high-density regions 24 and seven SAP low-density regions 25 are formed, but the number is not limited thereto. In FIG. 3, the SAP high-density region 24 is formed so as to be continuous in the width direction of the cover sheet 20, but may be formed intermittently.

In the cover sheet shown in FIG. 4, the SAP high-density regions 24 are arranged so as to be scattered in the SAP low-density regions 25. In FIG. 4, the SAP high-density regions 24 are arranged in a staggered pattern, which may be arranged in a grid pattern or may be arranged randomly. Further, the plan-view shape and size of each SAP high-density region 24 are not particularly limited.

7-2. 1st Embodiment FIG. 5 shows a plan view of an absorbent article (disposable auxiliary pad). FIG. 6 represents a schematic cross-sectional view taken along line AA of the absorbent article of FIG. FIG. 7 shows a schematic cross-sectional view taken along the line BB of the absorbent article of FIG.

The auxiliary pad 1 is arranged between the liquid-permeable top sheet 2, the impermeable back sheet 4, the absorber 6 arranged between them, and the top sheet 2 and the absorber 6. It has a diffused sheet 8 and a cover sheet 20 arranged between the top sheet 2 and the diffused sheet 8.

Side sheets 10 extending in the front-rear direction y of the auxiliary pad 1 are joined to both side edges of the top sheet 2 in the width direction x. The side sheet 10 is made of a liquid-impermeable plastic film, a water-repellent non-woven fabric, or the like. The side seat 10 is provided with an upright elastic member 12 at the inner end in the width direction of the auxiliary pad 1. When the auxiliary pad 1 is used, the inner end of the side seat 10 rises toward the wearer's skin due to the contraction force of the standing elastic member 12, which prevents lateral leakage of body fluid.

The absorber 6 has a front portion 61, a crotch portion 62, and a rear portion 63, and the crotch portion 62 is formed to be narrower than the front portion 61 and the rear portion 63. In FIGS. 6 and 7, the absorber 6 has one layer, but the absorber 6 may be provided with a plurality of layers. In FIG. 5, the plan view shape of the absorber 6 is an hourglass shape, but it may be a gourd shape.

The diffusion sheet 8 is arranged so that the entire plan-view shape of the diffusion sheet 8 overlaps the absorber 6 in the vertical direction. The diffusion sheet 8 is not arranged above the crossing line (dashed line) C that crosses the narrowest portion of the crotch portion in the width direction. In FIG. 5, the shape of the diffusion sheet 8 in a plan view is rectangular, but it may be trapezoidal, circular, or elliptical. In FIG. 5, only one diffusion sheet 8 is arranged, but a plurality of diffusion sheets 8 may be arranged. Further, in FIG. 5, the diffusion sheet 8 is arranged only on the rear side of the crossing line C of the absorber 6, but may be arranged on the front side of the crossing line C.

As the cover sheet 20, those shown in FIGS. 1 and 2 are arranged. The cover sheet 20 is composed of a liquid-permeable first non-woven fabric 21, a liquid-permeable second non-woven fabric 22, and a water-absorbent resin powder 23 arranged between the first non-woven fabric and the second non-woven fabric. ing. The cover sheet 20 is arranged so as to cover the entire diffusion sheet 8. The cover sheet 20 is not arranged above the crossing line C.

The cover sheet 20 has a SAP low-density region 25a formed so as to extend in the front-rear direction at the center in the width direction. The cover sheet 20 is arranged above the center portion in the width direction of the diffusion sheet 8 so that the SAP low density region 25a formed in the center portion in the width direction of the cover sheet is located. In FIG. 5, the cover sheet 20 has a rectangular shape in a plan view, but may have a trapezoidal shape, a circular shape, or an elliptical shape.

7-3. Second Embodiment FIG. 8 shows a plan view of an absorbent article (disposable auxiliary pad). FIG. 9 shows a schematic cross-sectional view taken along the line AA of the absorbent article of FIG. FIG. 10 shows a schematic cross-sectional view taken along the line BB of the absorbent article of FIG. In the following description, the parts that overlap with the embodiments of FIGS. 5 to 7 are designated by the same reference numerals, and the description thereof will be omitted.

The absorber 6 has a front portion 61, a crotch portion 62, and a rear portion 63, and the crotch portion 62 is formed to be narrower than the front portion 61 and the rear portion 63. The absorber 6 has a recess (through hole) 64 on the side surface of the top sheet. The recess 64 is provided so as to intersect a crossing line (dashed line) C that crosses the narrowest portion of the crotch portion in the width direction. In FIG. 8, the absorber 6 has one recess 64, but a plurality of recesses 64 may be provided. In FIGS. 9 and 10, the absorber 6 has two layers, but the absorber 6 may be provided with three or more layers. In FIG. 8, the plan view shape of the absorber 6 is an hourglass shape, but it may be a gourd shape.

In the auxiliary pad 1, one diffusion sheet 8 covering the rear end portion 65 of the absorber 6 is arranged. The diffusion sheet 8 is not arranged above the crossing line C of the absorber 6. In FIG. 8, the shape of the diffusion sheet 8 in a plan view is rectangular, but it may be trapezoidal, circular, or elliptical. In FIG. 8, only one diffusion sheet 8 is arranged, but a plurality of diffusion sheets 8 may be arranged. Further, a diffusion sheet may be arranged to cover the front end portion 66 of the absorber 6.

The cover sheet 20 is not arranged above the crossing line C. The cover sheet 20 is arranged above the center portion in the width direction of the diffusion sheet 8 so that the SAP low density region 25a formed in the center portion in the width direction of the cover sheet is located. Further, the cover sheet 20 is arranged so that the SAP low density region 25a is located above the opening.

The absorbent article of the present invention can be suitably used for, for example, an absorbent article used for absorbing body fluid discharged from the human body, particularly for incontinence pads, disposable diapers, sanitary napkins, disposable diapers and sanitary napkins. It can be suitably used as a disposable auxiliary pad to be attached and used.

1: Absorbent article (disposable auxiliary pad) 2: Top sheet, 4: Back sheet, 6: Absorbent, 8: Diffusion sheet, 10: Side sheet, 14: Lower layer absorber, 20: Cover sheet, 21: No. 1 non-woven fabric, 22: 2nd non-woven fabric, 23: water-absorbent resin powder, 24: SAP high-density region, 25: SAP low-density region, 61: front, 62: crotch, 63: rear, 64: recess, 65: Rear end, 66: Front end, C: Crossing line crossing the narrowest part of the crotch in the width direction

Claims (8)

A liquid-permeable top sheet, a liquid-impermeable back sheet, an absorber arranged between the top sheet and the back sheet, and a diffusion arranged between the top sheet and the absorber. It has a sheet and a cover sheet arranged between the top sheet and the diffusion sheet.
The cover sheet is composed of a liquid-permeable first non-woven fabric, a liquid-permeable second non-woven fabric, and a water-absorbent resin powder arranged between the first non-woven fabric and the second non-woven fabric, and is composed of the water-absorbent resin powder. A plurality of SAP high-density regions in which the resin powder is encapsulated between the first nonwoven fabric and the second nonwoven fabric are formed, and at least one SAP low-density region in which the water-absorbent resin powder does not substantially exist is formed.
The SAP low-density region and the SAP high-density region are formed so as to extend in the front-rear direction of the cover sheet, and these SAP low-density regions and the SAP high-density region are formed alternately in the width direction of the cover sheet. Has been
The cover sheet is arranged so as to cover the entire diffusion sheet, and at least the SAP low density region and a plurality of SAP high density regions are arranged so as to overlap the diffusion sheet in the vertical direction .
The absorber has an anterior portion, a crotch portion and a rear portion, the crotch portion is formed narrower than the anterior portion and the rear portion, and the narrowest position of the crotch portion of the absorber is located. An absorbent article characterized in that the cover sheet is not arranged above the crossing line crossing in the width direction. The absorbent article of claim 1 basis weight of the water-absorbent resin powder of the entire cover sheet is a ^{45g / m 2 ~150g / m 2} . The SAP basis weight of the water-absorbent resin powder of a high density region is ^{70g / m 2 ~250g / m 2} , according to claim 1 or 2 basis weight of the water-absorbent resin powder of the SAP low-density region is 20 g / m ² or less Absorbent article described in. The cover sheet has a SAP low density region formed so as to extend in the front-rear direction in the center in the width direction.
The absorbent article according to any one of claims 1 to 3, wherein the width of the SAP low density region formed in the center in the width direction is 18 mm to 31 mm. The absorbent article according to claim 4, wherein the cover sheet is arranged so that the SAP low-density region overlaps the central portion in the width direction of the diffusion sheet in the vertical direction. The absorbent article according to any one of claims 1 to 5, wherein the SAP low density region is embossed. The absorbent article according to any one of claims 1 to 6, wherein the diffusion sheet comprises a foam having continuous pores in the plane direction. The absorber has a front part, a crotch part and a rear part, and the crotch part is formed narrower than the front part and the rear part.
The absorbent article according to any one of claims 1 to 7, wherein the diffusion sheet is not arranged above the crossing line that crosses the narrowest position of the crotch portion of the absorber in the width direction. ..

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