JP2018057653A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article which has a diffusion sheet between a top sheet and an absorber, and which can suppress liquid return from the diffusion sheet to the top sheet.SOLUTION: An absorbent article comprises: a liquid permeable top sheet; a liquid impermeable back sheet; an absorber; a diffusion sheet; and a cover sheet. The cover sheet is formed of a liquid permeable first nonwoven fabric, a liquid permeable second nonwoven fabric, and water absorptive resin powder arranged between the first and second nonwoven fabrics. Plural SAP high density areas, in which the water absorptive resin powder is included between the first nonwoven fabric and the second nonwoven fabric are formed, and at least one SAP low density area, in which there is no water absorptive resin powder substantially, is formed. The cover sheet is arranged so that at least the SAP low density area and the plural SAP high density area are overlapped to the diffusion sheet in a vertical direction.SELECTED DRAWING: Figure 7

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 absorbent body.

  Absorbent articles are provided in absorbent articles such as disposable diapers and incontinence pads. The absorbent body has a water-absorbing resin powder, and the water-absorbing resin powder absorbs and holds body fluids such as urine discharged from the body. In such an absorbent article, it has been proposed to dispose a diffusion sheet in order to increase the absorption rate of body fluid or the like or to guide body fluid or the like to the entire absorbent body.

  For example, Patent Document 1 discloses an absorbent article in which an absorbent body is arranged between a top sheet made of a liquid permeable material and a back sheet made of a non-liquid permeable material. An absorbent article is described in which a sheet-like material that does not swell is disposed between the surface material and the absorber so as to cover at least a part of the absorber (Patent Document 1). See claim 1, paragraph 0011)).

  Patent Document 2 discloses a liquid-permeable top sheet, a water-repellent or liquid-impervious back sheet, an absorber disposed between the top sheet and the back sheet, and extending in the front-rear direction. And a diffusion part disposed between the diffusion layer and the top sheet, the diffusion part extending in the front-rear direction, and a sheet shape disposed 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)).

  Moreover, in the absorbent article, a technique for preventing the return of body fluid absorbed by the absorber has been proposed. For example, Patent Document 3 discloses a disposable absorbent article having an absorbent mat between a liquid-permeable top sheet and a liquid-impermeable back sheet, wherein the absorbent mat contains a water-absorbing resin powder. A sheet-like water-absorbing layer that does not contain pulp fibers, and a fiber aggregate layer that includes both pulp fibers and water-absorbent resin powder, in that order from the surface sheet side, and the fiber aggregate layer is pulp fibers A disposable absorbent article is described in which a fiber-existing region containing both the water-absorbent resin powder and a fiber-free region where both the pulp fiber and the water-absorbent resin powder do not exist are formed adjacent to each other (patent) Document 3 (see claim 1, paragraphs 0027-0029).

JP 2005-152250 A Japanese Patent Laying-Open No. 2015-167723 JP 2004-329664 A

  Conventionally, an absorbent article in which a diffusion sheet is arranged has been proposed in order to increase the absorption speed of body fluid or the like or to guide body fluid or the like to the entire absorber. In such an absorbent article, the diffusion sheet is often disposed between the top sheet and the absorbent body. However, since not a few body fluids remain in the diffusion sheet, there is a problem that the body fluid remaining in the diffusion sheet moves 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 the top sheet and the absorber, the 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 liquid-impervious back sheet, an absorbent body disposed between the top sheet and the back sheet, the top sheet, and the absorbent body. A diffusion sheet disposed between the top sheet and the diffusion sheet, the cover sheet comprising a liquid-permeable first nonwoven fabric and a liquid-permeable sheet. It is comprised from the 2nd nonwoven fabric, and the water absorbing resin powder arrange | positioned between the said 1st nonwoven fabric and the 2nd nonwoven fabric, and the said water absorbing resin powder was included between the 1st nonwoven fabric and the 2nd nonwoven fabric. A plurality of density regions are formed, at least one SAP low density region substantially free of the water-absorbent resin powder is formed, and the cover sheet includes at least the SAP low density region and a plurality of SAP high density regions. The diffusion Characterized in that it is arranged so as to overlap with the over preparative 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 to extend in the front-rear direction of the cover sheet, and the SAP low density region and the SAP high density region are alternately formed in the width direction of the cover sheet. It is preferable that 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 includes a foam having pores that are continuous in a planar direction. The absorbent body has a front part, a crotch part, and a rear part, the crotch part is formed narrower than the front part and the rear part, and the narrowest position of the crotch part of the absorbent body is It is preferable that the diffusion sheet is not disposed above a transverse line that crosses in the width direction.

  ADVANTAGE OF THE INVENTION According to this invention, in the absorbent article which provided the diffusion sheet between the top sheet and the absorber, the absorbent article by which the liquid return from a diffusion sheet to a top sheet was suppressed is obtained.

The top view of an example of a cover sheet. The typical sectional view of the VV line of Drawing 1. The top view of the other example of a cover sheet. The top view of the other example of a cover sheet. The top view of an example of the absorbent article of this invention. FIG. 6 is a schematic cross-sectional view taken along line AA in FIG. 5. FIG. 6 is a schematic cross-sectional view taken along line BB in FIG. 5. The top view of the other example of the absorbent article of this invention. FIG. 9 is a schematic cross-sectional view taken along line AA in FIG. 8. FIG. 9 is a schematic cross-sectional view taken along line BB in FIG. 8.

  The absorbent article of the present invention includes a liquid-permeable top sheet, a liquid-impervious back sheet, an absorbent body disposed between the top sheet and the back sheet, the top sheet, and the absorbent body. And a cover sheet disposed between the top sheet and the diffusion sheet. And the said cover sheet is comprised from the liquid-permeable 1st nonwoven fabric, the liquid-permeable 2nd nonwoven fabric, and the water absorbing resin powder arrange | positioned between the said 1st nonwoven fabric and the 2nd nonwoven fabric, A plurality of SAP high-density regions in which the water-absorbent resin powder is encapsulated between the first nonwoven fabric and the second nonwoven fabric are formed, and at least one SAP low-density region substantially free of the water-absorbent resin powder is formed. The cover sheet is characterized in that at least the SAP low density region and the plurality of SAP high density regions are arranged so as to overlap the diffusion sheet in the vertical direction.

  The SAP high-density region can absorb body fluid. Therefore, when the body fluid remains in the diffusion sheet, the body fluid can be absorbed and held in the SAP high-density region, and can be prevented from moving to the top sheet. The SAP low density region can permeate body fluid. Therefore, even when the bodily fluid that has passed through the top sheet reaches the cover sheet, the bodily fluid can be transmitted to the diffusion sheet through the SAP low density region.

  Further, the cover sheet is disposed so that the SAP low density region and the plurality of SAP high density regions overlap the diffusion sheet in the thickness direction. When the SAP high-density region absorbs body fluid, the thickness increases due to swelling of the water-absorbent resin powder. Therefore, when the SAP high-density region absorbs body fluid, the SAP low-density region is separated 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 void is formed in this portion. The voids thus generated facilitate the diffusion of the body fluid in the planar direction when the body fluid moves through the SAP low density region to the diffusion sheet.

  In the present invention, the front-rear direction means a direction extending in the front-rear direction of the wearer's crotch when the wearer wears the absorbent article. In the front-rear direction, a position applied to the wearer's ventral side is referred to as a front side, and a position applied to the wearer's back side is referred to as a rear side. The width direction means a direction orthogonal to the front-rear direction when the absorbent article is viewed in plan. Moreover, in this invention, the upper side means the wearer side at the time of wearing an absorbent article, and a lower side means the opposite side, ie, an outer side, from the wearer at the time of wearing an absorbent article. A direction extending from the upper side to the lower side is referred to as a vertical direction.

1. Diffusion sheet The diffusion sheet is disposed between the top sheet and the absorber. The diffusion sheet quickly diffuses 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 planar 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 in the front-rear direction of the diffusion sheet is preferably 20% or more, more preferably 30% or more, and more preferably 45% or less, more preferably when the length in the front-rear direction of the absorber 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 disposed is 100%. The following is preferable, more preferably 60% or less, and still more preferably 50% or less.

  The diffusion sheet is disposed so that the entire shape of the diffusion sheet in a plan view overlaps the absorber in the vertical direction. By arranging in this way, the body fluid dispersed in the diffusion sheet is finally easily taken into the absorber. It is preferable that the outer peripheral edge of the diffusion sheet is located inward from 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, and even 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 disposed above a transverse line that crosses the width direction (hereinafter may be referred to as “the narrowest portion”). The narrowest part is located in the vicinity of the user's urination port. Further, the narrowest portion is the portion where the side leakage is most likely to occur because the width of the absorber is narrow. When the diffusion sheet exists in the narrowest portion, body fluid or the like that has passed through the top sheet is diffused in the width direction by the diffusion sheet, and side leakage is likely to occur.

  In order to further reduce the occurrence of side leakage, it is preferable not to dispose a diffusion sheet near the narrowest portion. Therefore, the area where the diffusion sheet is not disposed is preferably within 65 mm in the front-rear direction from the transverse line, more preferably within 60 mm, and even more preferably within 55 mm.

  Only one diffusion sheet may be arranged, or a plurality of diffusion sheets may be arranged. As an arrangement mode of the diffusion sheet, an embodiment in which the diffusion sheet is arranged only behind the transverse line of the absorber; an embodiment in which the diffusion sheet is arranged only in front of the transverse line of the absorber; a rear side of the transverse line of the absorber; And an embodiment in which both are arranged on the front side.

  As described later, the diffusion sheet is preferably disposed so as to cover the front end portion and / or the rear end portion of the recess portion of the absorber when the absorber has a recess portion. That is, it is preferable that the diffusion sheet is disposed so that the body fluid diffused in the front-rear direction in the concave portion of the absorber 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 front-rear direction in the concave portion of the absorber reaches the front end portion and / or the rear end portion of the absorber, it is immediately taken into the diffusion sheet. And after disperse | distributing to the front-back direction and the width direction within a diffusion sheet, it transfers to the absorber below a diffusion sheet. Therefore, the body fluid that has permeated the top sheet is quickly dispersed in a wide range of the absorbent body through the concave portion of the absorbent body and the diffusion sheet, and is immediately absorbed and held.

  As an arrangement mode of the diffusion sheet, an embodiment in which only a diffusion sheet covering the front end portion of the concave portion of the absorber is disposed; an embodiment in which only a diffusion sheet covering the rear end portion of the concave portion of the absorber is disposed; The aspect which has arrange | positioned the diffusion sheet which covers a front-end part and the diffusion sheet which covers the rear-end part of the recessed part of the said absorber is mentioned.

  A plurality of diffusion sheets for the front end may be arranged, but it is preferable to arrange one sheet. Similarly, a plurality of diffusion sheets for the rear end may be arranged, but it is preferable to arrange one sheet. 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, more preferably 430, where the width of the concave portion is 100%. % Or less, more preferably 430% or less.

  In the case where the diffusion sheet for the front end is disposed, the length of the recess covered with the diffusion sheet for the front end is preferably 10% or more, more preferably, when the length in the front-rear direction of the recess is 100%. Is 17% or more, more preferably 24% or more, preferably 44% or less, more preferably 39% or less, and still more preferably 34% or less. Further, the distance from the front end portion of the concave portion of the absorber to the rear end portion of the diffusion sheet for the front end portion is preferably 100 mm or more, more preferably 110 mm or more, further preferably 120 mm or more, and preferably 170 mm or less. More preferably, it is 160 mm or less, More preferably, it is 150 mm or less.

  When arranging the diffusion sheet for the rear end, the recess length covered by the diffusion sheet for the rear end is preferably 10% or more when the length in the front-rear direction of the recess is 100%, More preferably, it is 17% or more, further preferably 24% or more, preferably 44% or less, more preferably 39% or less, and still more preferably 34% or less. Further, the distance from the rear end portion of the concave portion of the absorber to the front end portion of the diffusion sheet for the rear end portion is preferably 100 mm or more, more preferably 110 mm or more, still more preferably 120 mm or more, and 170 mm or less. Preferably, it is 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 the planar direction. Examples of the diffusion sheet include foam, three-dimensional solid knitted fabric, long fiber sheet, and nonwoven fabric.

  The foam has a large number of pores. The foam has a large number of pores that are air permeable. In the foam, each pore has a through-hole with the foam surface or a through-hole between adjacent pores. In addition, the shape of each pore is not specifically limited. The foam may have non-breathable pores. As the foam, a foam having pores continuous in a planar 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 planar 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, still more preferably 130 kg / m ³ or more, preferably 200 kg / m ³ or less, more preferably 180 kg / m. ³ or less, more preferably 170 kg / m ³ or less. If the apparent density of the polyurethane foam is 100 kg / m ³ or more, the water transmission rate is good, and if 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 including both air-permeable pores and non-air-permeable 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. If the thickness of the polyurethane foam is 0.5 mm or more, the mechanical strength of the polyurethane foam is good, and if 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, more preferably 100 L / min or less. If the air permeability of the polyurethane foam is 10 L / min or more, stuffiness inside the absorbent article can be prevented. The air permeability 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. The polyurethane foam is preferably subjected to a heat compression treatment in the thickness direction. By the thermal compression treatment, each skeleton forming the pore structure in the foam is compressed and deformed in the compression direction and deformed as if folded. As a result, the foam after the heat compression molding is in a state where the cell space is dense in the compression direction and the cell skeleton is aligned in the horizontal direction as compared to before the heat compression molding. Therefore, the water permeability in the thickness direction is further improved and the diffusibility in the horizontal direction is also excellent.

  The polyurethane foam preferably has a hydrophilic skeleton surface. If the skeleton surface is hydrophilic, the speed at which body fluid is taken into the diffusion sheet is further increased, and the absorption speed of the absorbent article is further improved.

  Whether 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, the polyurethane foam should not be bent. Next, using a dropper, 10 drops (0.05 ml) are gently placed on the polyurethane foam, and the time until these drops 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 determined as hydrophilic. Note that ion-exchanged water (surface tension (Wilhelmy method, platinum plate, 20 ° C., 65% RH): 70 mN / m or more) is used for the droplets.

  Examples of the polyurethane foam having a hydrophilic skeleton surface include those in which the polyurethane itself constituting the skeleton has hydrophilicity; and those obtained by hydrophilizing hydrophobic polyurethane foam. Examples of the polyurethane itself constituting the skeleton having hydrophilicity include those containing a polyalkylene oxide polyol in the polyol component. Hydrophobic polyurethane foams that have been hydrophilized include those in which at least a part of the surface of the hydrophobic polyurethane foam is coated with a surfactant, and hydrophobic polyurethane foams that are reactive gases such as ethylene oxide. And those having a hydrophilic group on the pore surface.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester salt 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 solid knitted fabric include resin fiber three-dimensional solid knitted fabric (for example, Fusion (registered trademark) manufactured by Asahi Kasei Fibers).

  Examples of the long fiber sheet include a long fiber sheet containing cellulose acetate long fibers. Cellulose acetate fibers have a cellulose skeleton and have high affinity with body fluids, so the body fluid uptake rate and diffusion rate are fast. Moreover, the hydroxyl group which cellulose skeleton has is acetylated, it does not have water absorption substantially, and affinity with a bodily fluid is not too high. Therefore, the body fluid diffused by the cellulose acetate fiber is likely to be finally absorbed by the water absorbing body.

  Examples of the nonwoven fabric include spunbond nonwoven fabric.

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 in the diffusion sheet is suppressed from moving to the top sheet. Thereby, the dry feeling after body fluid absorption becomes better. The cover sheet preferably has a plan view shape larger than that of the diffusion sheet, and the cover sheet is disposed so as to cover the entire diffusion sheet. The planar 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 nonwoven fabric, a liquid-permeable second nonwoven fabric, and a water-absorbent resin powder disposed between the first nonwoven fabric and the second nonwoven fabric. The cover sheet is formed with a plurality of SAP high-density regions in which the water absorbent resin powder is encapsulated between the first nonwoven fabric and the second nonwoven fabric, and the water absorbent resin powder is substantially absent. At least one low density region is formed.

  The SAP high-density region can absorb body fluid. Therefore, when the body fluid remains in the diffusion sheet, the body fluid can be absorbed and held in the SAP high-density region, and can be prevented from moving to the top sheet. The SAP low density region can permeate body fluid. Therefore, even when the bodily fluid that has passed through the top sheet reaches the cover sheet, the bodily fluid can be transmitted to the diffusion sheet through the SAP low density region.

  The cover sheet is disposed such that at least the SAP low density region and the plurality of SAP high density regions overlap the diffusion sheet in the vertical direction. When the SAP high-density region absorbs body fluid, the thickness increases due to swelling of the water-absorbent resin powder. Therefore, when the SAP high-density region absorbs body fluid, the SAP low-density region is separated 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 void is formed in this portion. The voids thus generated facilitate the diffusion of the body fluid in the planar direction when the body fluid moves through the SAP low density region to the diffusion sheet.

The basis weight 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, still more preferably 70 g / m ² or more, and more preferably 150 g / m ² or less. Preferably it is 130 g / m ² or less, more preferably 120 g / m ² or less. If the basis weight of the water-absorbent resin powder on 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, from the top sheet to the cover sheet. The body fluid that has been transferred to the diffusion sheet or the absorber can be permeated without any problem.

The basis weight 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. More preferably, it is 220 g / m < ² > or less, More preferably, it is 200 g / m < ² > or less. Basis weight of the water-absorbent resin powder of the SAP dense regions, if the 70 g / m ² or more can prevent the transmission of body fluid through the SAP high-density regions, included between the non-woven fabric as long as 250 g / m ² or less The absorptive absorbent resin powder can expand sufficiently.

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 basis weight of the water-absorbent resin powder in the SAP low density region is 20 g / m ² or less, the first nonwoven fabric and the second nonwoven fabric can be joined in the SAP low density region, and from the top sheet to the cover sheet. The body fluid that has been transferred to the diffusion sheet or the absorber becomes faster. The lower limit of the basis weight of the water absorbent resin powder in the SAP low density region is 0 g / m ² .

  It is preferable that the water-absorbent resin powder in the SAP high-density region is fixed to the first nonwoven fabric and / or the second nonwoven fabric with an adhesive. Examples of the adhesive include natural rubber, butyl rubber, polyisoprene, and other styrene elastomers such as SIS, SBS, SIBS, SEBS, and SEPS, ethylene / vinyl acetate copolymer (EVA), polyester, and acrylic. And hot-melt adhesives such as polyolefin elastomers.

  In the SAP low density region, the first nonwoven fabric and the second nonwoven fabric are joined. By bonding the first nonwoven fabric and the second nonwoven fabric, it is possible to prevent the water absorbent resin powder existing in the SAP high-density region from moving to the SAP low-density region. A method for joining the first nonwoven fabric and the second nonwoven fabric is not particularly limited, and examples thereof include an adhesive, heat sealing, and ultrasonic joining. The SAP low density region is preferably embossed. When embossing is performed, the non-woven fabric in the SAP low density region becomes partly very thin, so that the body fluid is more easily transmitted through this portion.

  The SAP low density region and the SAP high density region are formed to extend in the front-rear direction of the cover sheet, and the SAP low density region and the SAP high density region are alternately formed in the width direction of the cover sheet. It is preferable that By comprising in this way, the said space | gap is formed in the front-back direction of a cover sheet. Therefore, the diffusion rate of the body fluid in the front-rear 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, Preferably it is 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, more preferably 8 mm or less. More preferably, it is 7 mm or less.

  It is preferable that the cover sheet has an SAP low density region formed at the center in the width direction so as to extend in the front-rear 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, even 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 center portion in the width direction) overlaps the center portion in the width direction of the diffusion sheet in the vertical direction. .

  The cover sheet is preferably disposed so as to cover the entire diffusion sheet. The length in the front-rear direction of the cover sheet is preferably equal to or longer than the length in the front-rear direction of the absorber. 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 disposed above a transverse line that crosses in the width direction. In order to further reduce the occurrence of side leakage, it is also preferable not to place a cover sheet near the narrowest portion. Therefore, the region where the cover sheet is not disposed is preferably within 65 mm in the front-rear direction from the transverse line, more preferably within 60 mm, and even more preferably within 55 mm.

  The material of the first nonwoven fabric and the second nonwoven fabric is not particularly limited as long as it is a liquid-permeable nonwoven fabric. For example, non-woven fabrics formed from hydrophilic fibers such as cellulose, rayon and cotton; non-woven fabrics formed from hydrophobic fibers such as polyolefin (polypropylene, polyethylene), polyester and polyamide, and the surface of the hydrophobic fibers is surface active Nonwoven fabric hydrophilized with an agent. Examples of the water absorbent resin powder include water absorbent resin powders such as polyacrylic acid, polyaspartic acid, cellulose, and starch / acrylonitrile.

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

4). Back sheet The said back sheet is a sheet | seat located on the opposite side to a wearer, ie, an outer side, at the time of wear of an absorbent article. The back sheet is not particularly limited as long as it is liquid-impermeable. In the present invention, the liquid impermeability includes water repellency. The shape of the back sheet in plan view is not particularly limited, and may be adjusted according to the shape of the absorber.

  Examples of the backsheet include hydrophobic nonwoven fabrics, plastic films, and laminates of plastic films and nonwoven fabrics. Examples of the hydrophobic nonwoven fabric include nonwoven fabrics formed from hydrophobic fibers such as polyolefin (polypropylene, polyethylene), polyester, and polyamide. Examples of the plastic film include films formed from resins such as polyolefin (polypropylene, polyethylene), polyester, and polyamide. The nonwoven fabric laminated on the plastic film may be either hydrophilic or hydrophobic.

5. Absorber The absorber is disposed between the top sheet and the back sheet. The absorber absorbs and retains body fluids. The absorber has a front part, a crotch part, and a rear part. The said front part is a part located in a wearer's stomach side at the time of wear of an absorptive article. The said rear part is a part located in a wearer's back side at the time of wear of an absorbent article. The crotch portion is located between the front portion and the rear portion, and is a portion located in the crotch of the wearer when the absorbent article is worn.

  The planar view shape of the absorber is not particularly limited. The absorber preferably has a crotch portion formed narrower than 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, and still more preferably 50% or more. And is preferably 60% or less, more preferably 57% or less, and still more preferably 55% or less. The width of the narrowest part 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, and still more preferably 121 mm or less. The shape of the absorber in plan view 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, and 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, and further preferably 230 mm or less. .

  The absorber preferably has a recess extending in the front-rear direction on the side of the topsheet. By having the said recessed part, the bodily fluid which reached | attained the absorber can be immediately diffused in the front-back direction in the said recessed part. The shape of the concave portion in plan view is preferably a rectangular shape or a rounded rectangular shape.

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

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

  It is sufficient that at least one recess is provided. Although a plurality of recesses may be arranged side by side in the width direction, it is preferable to provide one recess at substantially the center in the width direction of the absorber. The width of the concave portion is preferably 13% or more, more preferably 15% or more, still more preferably 17% or more, and more preferably 24% or less, more preferably 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, and further preferably 23 mm or less.

  It is preferable that the concave portion is provided so as to intersect a transverse line that crosses the narrowest portion of the crotch portion in the width direction. The narrowest part is located in the vicinity of the user's urination port. Further, the narrowest portion is the portion where the side 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 at the crotch portion can be suppressed. In the case where 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 center portion in the front-rear direction of the absorber A transverse line will be drawn in the part.

  The position where the recess and the transverse 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 transverse line is located at 30% to 70%. Preferably, it is 40% to 60%, more preferably 45% to 55%. If the intersection with the transverse line is provided so as to be located at 30% to 70% of the recess, the body fluid that has reached the narrowest part can be evenly distributed in the front part and the rear part of the absorber.

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

  The absorber may be only one layer or two or more layers. When the absorber has two or more layers, a concave portion is provided in the absorber that is positioned closest to the top sheet. In addition, when making the said recessed part into an opening, it is preferable to make an absorber into 2 layers. Moreover, it is preferable that another absorber is disposed below the opening.

  The absorber is not particularly limited as long as it includes an absorbent material that can absorb excrement such as urine. Examples of the absorbent body include a molded body obtained by molding an absorbent material into a predetermined shape, and an absorbent material covered with a sheet member such as a paper sheet (eg, tissue paper or thin paper) or a liquid-permeable nonwoven sheet. Can be used.

  Examples of the absorbent material include hydrophilic fibers such as pulverized pulp fiber and cellulose fiber, and water-absorbing resins such as polyacrylic acid-based, polyaspartic acid-based, cellulose-based, and starch / acrylonitrile-based materials. The water-absorbing material may include polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as polyethylene terephthalate, and heat-fusible fibers such as polyamide fibers. These heat-fusible fibers may be subjected to a hydrophilic treatment with a surfactant or the like in order to increase the affinity with body fluid such as urine.

  The absorbent material preferably contains hydrophilic fibers from the viewpoint of increasing the absorption rate of urine and the like. Moreover, it is preferable that an absorptive material contains a water absorbing resin from the point which raises absorption capacity. As the absorbent material, for example, it is preferable to use a material in which a water-absorbing resin is mixed or dispersed in an aggregate of hydrophilic fibers.

6). Absorbent article Examples of the absorbent article of the present invention include an incontinence pad, a disposable diaper, a sanitary napkin, a disposable diaper main body, and a disposable auxiliary pad to be attached to the sanitary napkin.

  When the absorbent article is an incontinence pad, a sanitary napkin, or a disposable auxiliary pad, for example, an absorbent body and a diffusion sheet are disposed between a liquid-permeable top sheet and a liquid-impermeable back sheet. . Examples of the shape of the incontinence pad, sanitary napkin or disposable auxiliary pad include an hourglass shape and a gourd shape. Further, if necessary, liquid-impervious side sheets may be provided on both sides in the width direction of the liquid-permeable top sheet. The side sheets are bonded to the upper surfaces on both sides in the width direction of the top sheet, and the side sheets inward in the width direction from the bonding points form a pair of rising flaps along both side edges of the absorber.

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

  When the absorbent article is a disposable diaper, the disposable diaper forms, for example, a diaper main body in which a laminate composed of an inner sheet and an outer sheet is composed of a front abdomen, a back part, and a crotch part positioned therebetween. The water absorbing body and the diffusion sheet may be disposed in the crotch portion. The 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 front abdomen, the back part, and the crotch part. You may have. The inner sheet is preferably hydrophilic or water repellent, and the outer sheet is preferably water repellent.

  The disposable diaper is preferably provided with rising flaps along both side edges. By providing the rising flap, it is possible to prevent side 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 the side sheet are preferably water-repellent.

7). Specific Example Next, the absorbent article of the present invention will be described with reference to the drawings. The cover sheet used for this invention is demonstrated with reference to FIGS. The absorbent article of the present invention will be described with reference to FIGS. In the figure, the arrow x is defined as the width direction, and the arrow y is defined as the front-rear direction. A direction on the surface formed by the arrows x and y is defined as a plane direction. In addition, the vertical direction to the surface formed by the arrows x and y represents the vertical direction z.

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 line VV in FIG. The cover sheet 20 includes a liquid-permeable first nonwoven fabric 21, a liquid-permeable second nonwoven fabric 22, and a water absorbent resin powder 23 disposed between the first nonwoven fabric 21 and the second nonwoven fabric 22. Has been. The cover sheet 20 is formed with a plurality of SAP high-density regions 24 in which the water absorbent resin powder 23 is enclosed between the first nonwoven fabric 21 and the second nonwoven fabric 22, and the water absorbent resin powder 23 is A plurality of SAP low density regions 25 that do not substantially exist are formed. In FIG. 1, the hatched portion 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 the SAP low density region 25 and the SAP high density region 24 are formed on the cover sheet 20. They are alternately formed in the width direction x. The cover sheet 20 has an SAP low density region 25a formed in the center in the width direction so as to extend in the front-rear direction.

  In FIG. 1 and FIG. 2, four SAP high-density regions 24 and five SAP low-density regions 25 are formed, but the number is not limited to these. In FIG. 2, the water-absorbing resin powder 23 is not disposed in the SAP low-density region 25, but some water-absorbing resin powder 23 is present in the SAP low-density region 25 as long as the effect of the present invention is not impaired. May be. 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 plan views of other examples of the cover sheet. In the following description, the same parts as those in the embodiment of 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. 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 to these. 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 in the SAP low-density region 25 so as to be scattered. In FIG. 4, the SAP high-density regions 24 are arranged in a staggered manner, but they may be arranged in a lattice shape or randomly. Further, the shape and size of each SAP high-density region 24 in plan view are not particularly limited.

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

  The auxiliary pad 1 is arranged between the liquid-permeable top sheet 2, the liquid-impermeable back sheet 4, the absorbent body 6 disposed therebetween, and the top sheet 2 and the absorbent body 6. And a cover sheet 20 disposed between the top sheet 2 and the diffusion sheet 8.

  Side sheets 10 extending in the front-rear direction y of the auxiliary pad 1 are joined to both side edges in the width direction x of the top sheet 2. The side sheet 10 is composed of a liquid-impermeable plastic film, a water-repellent nonwoven fabric, or the like. The side seat 10 is provided with a standing 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, thereby preventing side leakage of body fluid.

  The absorber 6 has a front part 61, a crotch part 62, and a rear part 63, and the crotch part 62 is formed narrower than the front part 61 and the rear part 63. 6 and 7, the absorber 6 is a single layer, but the absorber 6 may be provided in multiple layers. In FIG. 5, the shape of the absorber 6 in plan view is an hourglass shape, but may be a gourd shape.

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

  The cover sheet 20 is arranged as shown in FIGS. The cover sheet 20 includes a liquid-permeable first nonwoven fabric 21, a liquid-permeable second nonwoven fabric 22, and a water absorbent resin powder 23 disposed between the first nonwoven fabric and the second nonwoven fabric. ing. The cover sheet 20 is disposed so as to cover the entire diffusion sheet 8. The cover sheet 20 is not disposed above the transverse line C.

  The cover sheet 20 has an SAP low density region 25a formed at the center in the width direction so as to extend in the front-rear direction. The cover sheet 20 is disposed 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. Although the plan view shape of the cover sheet 20 is rectangular in FIG. 5, it may be trapezoidal, circular, or elliptical.

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

  The absorber 6 has a front part 61, a crotch part 62, and a rear part 63, and the crotch part 62 is formed narrower than the front part 61 and the rear part 63. The absorber 6 has a recess (through hole) 64 on the side surface of the top sheet. The concave portion 64 is provided so as to intersect a transverse line (dashed line) C that crosses the narrowest portion of the crotch portion in the width direction. In FIG. 8, the absorbent body 6 has one recess 64, but a plurality of recesses 64 may be provided. 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 shape of the absorber 6 in plan view is an hourglass shape, but 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 disposed. The diffusion sheet 8 is not disposed above the transverse line C of the absorber 6. In FIG. 8, the planar view shape of the diffusion sheet 8 is rectangular, but it may be trapezoidal, circular, or elliptical. In FIG. 8, only one diffusion sheet 8 is arranged, but a plurality of sheets may be arranged. Further, a diffusion sheet that covers the front end portion 66 of the absorbent body 6 may be disposed.

  The cover sheet 20 is not disposed above the transverse line C. The cover sheet 20 is disposed 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 such 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 to absorb bodily fluids discharged from the human body, and is particularly suitable 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: Absorber, 8: Diffusion sheet, 10: Side sheet, 14: Lower layer absorber, 20: Cover sheet, 21: No. 1 non-woven fabric, 22: second non-woven fabric, 23: water-absorbing resin powder, 24: SAP high-density region, 25: SAP low-density region, 61: front, 62: crotch, 63: rear, 64: recess, 65: Rear end portion, 66: front end portion, C: transverse line crossing the narrowest portion of the crotch portion in the width direction

Claims (8)

A liquid-permeable top sheet, a liquid-impermeable back sheet, an absorber disposed between the top sheet and the back sheet, and a diffusion disposed between the top sheet and the absorber. A sheet, and a cover sheet disposed between the top sheet and the diffusion sheet,
The cover sheet is composed of a liquid-permeable first nonwoven fabric, a liquid-permeable second nonwoven fabric, and a water-absorbing resin powder disposed between the first nonwoven fabric and the second nonwoven fabric, and the water-absorbing property. 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 absorbent sheet, wherein the cover sheet is arranged so that at least the SAP low density region and the plurality of SAP high density regions overlap with the diffusion sheet in the vertical 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 as described in 1.   The SAP low density region and the SAP high density region are formed to extend in the front-rear direction of the cover sheet, and the SAP low density region and the SAP high density region are alternately formed in the width direction of the cover sheet. The absorptive article according to any one of claims 1 to 3.   The absorbent article according to claim 4, wherein the cover sheet is disposed such that the SAP low-density region overlaps with the center 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 absorptive article according to any one of claims 1 to 6 in which said diffusion sheet contains foam which has a pore which continues in a 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 absorptive article according to any one of claims 1 to 7 in which said diffusion sheet is not arranged above a transverse line which crosses a position where said crotch part of said absorber is narrowest in the width direction. .

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