JP2018089048A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article excellent in absorption performance such as a diffusibility, absorption rate and a liquid return amount and excellent in shape retention of an absorber.SOLUTION: An absorbent article 1 comprises: a liquid permeable top sheet 21; a liquid impermeable back sheet 23; and an absorber 22 arranged between the top sheet 21 and the back sheet 23. The absorber 22 comprises a ventral part 1a, a back side part 1c, and a crotch part 1b arranged between the ventral part 1a and the back side part 1c, and on at least the crotch part 1b of the absorber 22, plural filamentous slit parts 221 extending in a longitudinal direction of the absorber 22 are provided. The slit parts 221 contain no fluff pulp and high absorbent polymer and penetrate the absorber 22 in a thickness direction of the absorber 22. A total volume of the slit parts 221 under compression of 35 gf/cm, in which a wearing time of the absorbent article 1 is supposed, is 2000 mmor larger and 15000 mmor smaller.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an absorbent article such as a light incontinence pad, a pants-type paper diaper, and a taped paper diaper, and more particularly to a baby paper diaper.

  In general, absorbent articles such as light incontinence pads, pants-type paper diapers, taped paper diapers, etc. are composed of a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between both sheets. , Is composed of. Thereby, body fluids, such as urine, are absorbed by an absorber through a top sheet, and do not leak outside by a back sheet. Such an absorbent article has been devised in various ways to improve the absorbability of body fluids, improve the wearer's wearing feeling, prevent leakage, and the like.

  In Patent Document 1, in order to maintain the effect of the groove even when liquid absorption or external force is applied, the absorption speed is not lowered, and the deterioration of the wearing feeling is prevented, so that the groove shape or It is provided with an absorbent recess formed in a slit shape, and embossed from the surface side of the liquid-permeable surface sheet, with an emboss width smaller than the groove width of the absorbent recess along the absorbent recess inside the absorbent recess An absorbent article provided with an embossed portion is disclosed.

  In Patent Document 2, an upper opening is provided in the upper absorbent body and the upper absorbent body extends in the longitudinal direction and at least partly extends to the lower absorbent body for the purpose of absorbing urine effectively by SAP with high liquid diffusibility. A lower opening that overlaps, and a plurality of superabsorbent polymers (SAP) between the upper absorber and the lower absorber, the width direction of the opening penetrating portion where at least the upper opening and the lower opening overlap An absorbent article provided with an SAP layer formed on both the left and right sides of the sheet is disclosed.

JP 2015-47432 A Japanese Patent Laid-Open No. 2006-140559

  Here, the absorbent article which concerns on patent document 1 and patent document 2 has ensured the diffusion path | route of the bodily fluid in an absorber by providing a slit in an absorber. However, when a slit is provided in the absorbent body, the absorbent body may be less stable with respect to the pressure applied to the absorbent body during absorption of the absorbent article or after absorption of body fluid during wearing, etc. It is necessary to consider the problem of shape retention. On the other hand, if the absorbent body is not provided with a slit, if the absorbent polymer absorbs the body fluid and swells, the path through which the body fluid diffuses in the absorbent body is blocked, so the absorption rate may be slow, and the diffusibility In this case, a problem occurs in the absorption performance such as the absorption speed and the liquid return amount.

  Accordingly, an object of the present invention is to provide an absorbent article having excellent absorption performance such as diffusibility, absorption speed and liquid return amount, and excellent shape retention of the absorbent body.

In view of the above problems, the present inventors conducted extensive research. As a result, a predetermined slit portion is provided in at least the crotch portion of the absorbent body composed of the ventral portion, the dorsal portion, and the crotch portion between the ventral portion and the dorsal portion, and it is assumed that the absorbent article is worn The present inventors have found that the above problem can be solved by adjusting the total volume of the slit portion to a predetermined value under a pressure of 35 gf / cm ² , and have completed the present invention. Specifically, the present invention provides the following.
(1) An embodiment of the present invention is an absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet. The absorber comprises a ventral part, a dorsal part, and a crotch part between the ventral part and the dorsal part, and at least the crotch part of the absorber has a longitudinal direction of the absorber. A plurality of linear slit portions extending are provided, the slit portions do not include fluff pulp and superabsorbent polymer, penetrate the absorber in the thickness direction of the absorber, and wear the absorbent article under a pressure of 35gf / cm ² assuming a time, the total volume of said slit portion is absorbent article is 2000 mm ³ or more 15000 ³ below.
(2) In the absorbent article according to (1), the ratio of the total volume of the slit portion to the total volume of the absorber is 35 gf / cm ² under the pressure when the absorbent article is worn. It may be 2.5% or more and 7.5% or less.
(3) In the absorbent article according to (1) or (2), in the cross-section in the width direction of the crotch part of the absorbent article, the ratio of the sectional area of the slit part of the crotch part to the sectional area of the crotch part is 10 % Or more and 25% or less.

The absorbent article of the present invention is provided with a plurality of linear slit portions extending in the longitudinal direction of the absorbent body at least in the crotch portion of the absorbent body so as to penetrate the absorbent body in the thickness direction of the absorbent body. Contains no fluff pulp and superabsorbent polymer. Thereby, the path | route which a bodily fluid diffuses within an absorber can be ensured, and it can be set as the absorbent article excellent in absorption performance, such as a diffusivity, an absorption speed, and a liquid return amount. Further, the absorbent article of the present invention, under a pressure of 35gf / cm ² was assumed when wearing the absorbent article, the total volume of the slit portion is 2000 mm ³ or more 15000 ³ below. Thereby, even when the slit portion is provided, the absorbent body has good stability of the shape of the absorbent body against the pressure applied to the absorbent body during wearing of the absorbent article, after absorption of body fluid during wearing, etc. It can be set as the absorbent article excellent in shape retention property.

It is the top view which looked at the absorptive article concerning the embodiment of the present invention from the top sheet side. It is a schematic sectional drawing of the absorbent article in the AA line of FIG. It is explanatory drawing which shows the outline of the crotch part cross-sectional area of an absorbent article in FIG. 1, and the slit part cross-sectional area. When the absorbent article which concerns on embodiment of this invention is used as a tape stop paper diaper, it is the top view seen from the top sheet side.

  Embodiments of the present invention will be described in detail below, but these are given for illustrative purposes and do not limit the present invention. Note that the same number is assigned to the same element throughout the description of the embodiment. Moreover, in description of this specification, the time of wearing of the absorbent article 1 means at least one after wearing of the absorbent article 1 and after wearing. The longitudinal direction of the absorbent article 1 is a direction extending before and after the wearer when the absorbent article 1 is worn, and is a direction indicated by a symbol Y in the figure. Moreover, the width direction of the absorbent article 1 is a direction that is transverse or orthogonal to the longitudinal direction, and is a direction indicated by a symbol X in the drawing. Furthermore, the skin contact surface is a surface that is disposed on the wearer's skin side during wearing among the front and back surfaces of each member such as the absorber, and the non-skin contact surface is each member such as the absorber. Of the front and back surfaces, the surface is directed to the side opposite to the wearer's skin when worn. Body fluid refers to fluid discharged from the body, such as urine, blood, and water in loose stool. Further, examples of the absorbent article 1 include light incontinence pads, pants-type paper diapers, and tape-fastened paper diapers, regardless of whether they are for babies or adults. There may be.

[Absorbent articles]
Drawing 1 is a top view which looked at absorptive article 1 concerning an embodiment of the present invention from the top sheet 21 side. 2 is a schematic cross-sectional view of the absorbent article 1 taken along the line AA in FIG. As shown in FIGS. 1 and 2, the absorbent article 1 includes a liquid-permeable top sheet 21 disposed on the skin contact surface side, and a liquid-impermeable back disposed to face the top sheet 21. The sheet | seat 23 and the absorber 22 arrange | positioned between the top sheet | seat 21 and the back sheet | seat 23 are provided. Thereby, the absorber 22 becomes the structure pinched | interposed between the top sheet 21 and the back sheet | seat 23, and becomes a structure of a light incontinence pad type absorbent article. And in the absorbent article 1, the crotch which mutually couple | bonds the abdominal side part 1a located in a wearer's abdomen, the back side part 1c located in a wearer's back part, and the abdominal side part 1a and the back side part 1c. Part 1b is defined.

<Top sheet>
The top sheet 21 only needs to be formed from a base material having liquid permeability such that body fluid moves to the absorbent body 22. For example, a nonwoven fabric such as an air-through nonwoven fabric, a thermal bond nonwoven fabric, and a spunbond nonwoven fabric, It is formed from a material such as a composite nonwoven fabric obtained by laminating spunbond, an open film such as an open polyethylene film, a foam film such as polyethylene foam or urethane foam, or a composite sheet obtained by laminating these. Further, the top sheet 21 may be embossed or perforated on the surface in order to improve the liquid permeability. As a method for performing these embossing and perforating processes, a known method can be carried out without limitation. In order to reduce irritation to the skin, the top sheet 21 may contain a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a moisturizing agent and the like.

From the viewpoint of strength, workability, and liquid return amount, the basis weight of the top sheet 21 is preferably 15 g / m ² or more and 40 g / m ² or less. Although there is no restriction | limiting in particular as a shape of the top sheet 21, What is necessary is just the shape which covers the absorber 22 required in order to guide a bodily fluid to the absorber 22 so that there may be no leak.

(Three-dimensional gather)
As shown in FIG.1 and FIG.2, in order to prevent the side leakage of the bodily fluid excreted by the user, the absorbent article 1 has a three-dimensional gather on the top sheet 21 along the longitudinal direction of the absorbent article 1. A pair of three-dimensional gathers 24 having the elastic member 241 and the three-dimensional gather sheet 242 may be provided. As for the three-dimensional gather 24, the outer end part of the width direction of the absorbent article 1 may be fixed to the back sheet 23. Further, the three-dimensional gather 24 has the longitudinal front and rear end portions fixed to the top sheet 21 at the inner end in the width direction of the absorbent article 1, and the central portion between the longitudinal front and rear end portions on the top sheet 21. You may distribute | arrange so that it may become a free end which is not fixed. In addition, a pair of three-dimensional gather elastic members 241 are provided along the longitudinal direction of the absorbent article 1, and the pair of three-dimensional gather elastic members 241 at the center in the width direction of the absorbent article 1 correspond to a pair of three-dimensional bodies. The gather sheet 242 may be encapsulated. Thereby, the three-dimensional gather 24 can have a standing property and can be deformed in accordance with the wearer's body shape. As the three-dimensional gathered elastic member 241, for example, a polyurethane thread, a strip-like polyurethane film, a thread-like or strip-like natural rubber, or the like is used. Liquid nonwoven fabrics such as spunbond nonwoven fabrics, meltblown nonwoven fabrics, and composite nonwoven fabrics laminated with spunbond / meltblown / spunbond are used.

<Back sheet>
The back sheet 23 may be formed using a base material having liquid impermeability so that the body fluid held by the absorbent body 22 does not wet the clothing, and the resin film or the resin film and the nonwoven fabric are laminated. Formed from a material such as a composite sheet. The non-woven fabric used for the composite sheet is not particularly limited, and examples thereof include a spunbond nonwoven fabric and a meltblown nonwoven fabric, or a composite nonwoven fabric obtained by laminating spunbond / meltblown, spunbond / meltblown / spunbond, and composite materials thereof. Can be mentioned. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, and a composite film of polyethylene and polypropylene.

From the viewpoint of strength and workability, the basis weight of the back sheet 23 is preferably 13 g / m ² or more and 23 g / m ² or less. Moreover, in order to prevent the stuffiness at the time of mounting | wearing, it is preferable to give the back seat | sheet 23 breathability. In order to provide the back sheet 23 with air permeability, for example, a filler may be added to the resin film of the base material, or the back sheet 23 may be embossed for perforation. In addition, calcium carbonate can be mentioned as a filler, The compounding method can perform a well-known method without a restriction | limiting.

(Side flap)
As shown in FIG. 4, the absorbent article 1 of the present invention may form at least a pair of side flaps 26 on both sides in the width direction of the back side portion 1 a and the back side portion 1 c of the backsheet. Further, each side flap 26 of the back side portion 1c is provided with side panels 261 on both side edges in the width direction on the free end side, and two fastening tapes 262 on width direction edges on the free end side of the side panel 261. May be. Further, the side panel 261 and the fastening tape 262 are not limited to those formed by separate members, and may be formed integrally with each other. The fastening tape 262 is provided with fastening means 263 formed of a hook member constituting a surface fastener for fastening the abdominal side part 1a and the back side part 1c on the skin contact surface side, and on the free end side of the fastening means 263. A pinch 264 may be provided at the tip of each fastening tape 262. On the other hand, the clothing side surface of the abdomen portion 1a may be provided with a target tape (not shown) formed of a loop member constituting a hook-and-loop fastener, and is fastened when the absorbent article 1 is worn on the wearer. The means 263 is fixed to the target tape which is a loop member. Thereby, the absorbent article 1 of this invention can be set as the structure of a tape stop paper diaper.

  In addition, as a base material of the side flap 26, the nonwoven fabric which consists of polyethylene, a polypropylene, a polystyrene, etc. can be mentioned, You may combine these base materials independently or more than one. Moreover, as a base material of the side panel 261 and the fastening tape 262, the resin film and nonwoven fabric which consist of polyethylene, a polypropylene, a polystyrene, etc. can be mentioned, You may combine these base materials independently or multiple. The hook member refers to a member that is three-dimensionally molded or raised in a hook shape among the members that constitute the hook-and-loop fastener, and the loop member is a member that forms a pair with the hook member, and is closely packed in a loop shape. It refers to a member that has been brushed. The hook-and-loop member is configured by a pair of the hook member and the loop member. When the absorbent article 1 is worn, the abdomen 1a is brought to the abdomen side of the wearer with the back side 1c applied to the wearer's back, and the fastening tape 262 is fastened to the target tape. Can be worn by the wearer.

(Leg gather)
As shown in FIG. 4, the absorbent article 1 of the present invention may be provided with a pair of left and right leg gathers 27 from the abdominal side 1a of the absorbent article 1 through the crotch part 1b to the back side part 1c. . The leg gathers 27 are formed of, for example, an elastic member such as rubber thread and a sheet such as a nonwoven web. By providing the leg gathers 27, it is possible to improve the fit at the part around the crotch.

(West gather)
As shown in FIG. 4, the absorbent article 1 of the present invention may be provided with a waist gather 28 configured to pull and hold the absorbent article 1 against the wearer's waist. The waist gathers 28 may have any shape such as a thread shape, a strip shape, and a waist belt shape, and are arranged substantially along the width direction rather than the longitudinal direction of the absorbent article 1 to control the expansion / contraction characteristics of the absorbent article 1. is there. As the waist gathers 28, any elastic shrinkable material such as one or a plurality of thread rubbers, a waist belt in which the thread rubbers are fixed to a nonwoven web, an elastomer film, an elastic foam material, and an elastomer cloth can be used.

(Indicator means)
The absorbent article 1 of the present invention is provided with indicator means (not shown) between the absorbent body 22 and the back sheet 23 that makes it possible to distinguish from the outside that the body fluid has been revealed and has been discharged when wet with the body fluid. A plurality of backsheets 23 may be provided at the center in the width direction so as to extend linearly in the longitudinal direction. The indicator means may be, for example, a base polymer such as polyethylene glycol or glycerin mixed with an indicator such as ethyl red or bromophenol blue and an adhesive such as wax and bonded by hot melt.

<Absorber>
As shown in FIG.1 and FIG.2, in the absorbent article 1 of this invention, the absorber 22 has the abdominal part 1a, the crotch part 1b, and the back | dorsal part 1c. The absorber 22 may be a single layer or multiple layers.

The absorber 22 contains an absorbent fiber as a base material and a superabsorbent polymer (SAP). The basis weight of the entire absorbent body 22 is preferably 300 g / m ² or more and 600 g / m ² or less, and more preferably 400 g / m ² or more and 500 g / m ² or less.

(Absorbent fiber)
The absorbent fiber is not particularly limited as long as it is generally used for absorbent articles such as sanitary napkins, paper diapers, and urine pads. For example, fluff pulp, cotton, rayon, acetate, tissue, absorbent paper, hydrophilic paper Can be mentioned. Among these, it is preferable to use fluff pulp from the viewpoint of absorbability. Examples of fluff pulp include wood pulp (for example, softwood bleached kraft pulp (N-BKP) such as Southern pine or Douglas fir), synthetic fiber, resin fiber, non-wood pulp, etc. it can. When fluff pulp is used as the absorbent fiber as the base material for the absorbent body 22, the basis weight of the absorbent fiber is preferably 150 g / m ² or more and 270 g / m ² or less for the entire absorbent body 22. More preferably, it is 190 g / m ² or more and 230 g / m ² or less. Thereby, more body fluids can be absorbed without impairing the touch.

(Super absorbent polymer)
The superabsorbent polymer of the absorbent body 22 is not particularly limited as long as it absorbs body fluids and can prevent backflow. Sodium polyacrylate, polyaspartate, (starch-acrylic acid) graft Those formed from materials such as a copolymer, (acrylic acid-vinyl alcohol) copolymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof can be used. Among these, sodium polyacrylate is preferable from the viewpoint of the amount of absorption per weight.

The basis weight of SAP contained in the absorbent body 22, the entire absorbent member 22, more that it is 150 g / ^{m 2} or more 380 g / ^{m 2} or less and preferably, 190 g / ^{m 2} or more 200 g / ^{m 2} or less preferable. By setting it within the above numerical range, gel blocking in the absorber 22 can be prevented, and a large amount of body fluid can be absorbed in the absorber 22.

  In the absorbent body 22, the absorbent fiber and the SAP are preferably formed by mixing SAP particles in the absorbent fiber, or an SAP sheet in which the SAP particles are fixed between the absorbent fibers. Further, for the purpose of preventing leakage of SAP particles and stabilizing the shape of the absorber 22, the absorber 22 may be wrapped in a carrier sheet 25. The base material of the carrier sheet 25 may be any material having hydrophilicity, and examples thereof include hydrophilic nonwoven fabrics such as tissue, absorbent paper, and airlaid nonwoven fabric. When a plurality of carrier sheets 25 are provided, the base material of the carrier sheet 25 may be the same or different.

(slit)
As shown in FIGS. 1 and 2, the absorbent article 1 of the present invention is provided with a plurality of linear slit portions 221 extending in the longitudinal direction of the absorbent body 22 at least in the crotch portion 1b of the absorbent body 22. The number is preferably 2 or more and 4 or less, more preferably 2. Thereby, the path | route which a bodily fluid diffuses within the absorber 22 can be ensured, and it can be set as the absorbent article 1 excellent in absorption performance, such as a diffusivity, an absorption speed, and a liquid return amount.

  Moreover, the slit part 221 does not contain fluff pulp and a superabsorbent polymer, and penetrates the absorber 22 in the thickness direction of the absorber 22.

((Total volume of slit part))
The absorbent article 1 of the present invention, under a pressure of 35gf / cm ² was assumed when wearing the absorbent article 1, the total volume of the slit 221 is at 2000 mm ³ or more 15000 ³ or less, 5000 mm ³ or more 12000 mm ³ preferably less, and more preferably 7000 mm ³ or more 10000 mm ³ or less. By setting the total volume of the slit part 221 within the above numerical range, even when the slit part 221 is provided, the pressure applied to the absorbent body 22 during wearing of the absorbent article 1 or after absorbing bodily fluid during wearing. Thus, the absorbent article 1 having excellent shape stability of the absorbent body 22 can be obtained. Furthermore, since the bodily fluid is widely dispersed in the absorber 22 by setting the total volume of the slit portion 221 within the above numerical range, the absorbent article 1 having excellent absorption performance such as diffusibility, absorption speed, and liquid return amount. It can be. The total volume of the slit part 221 is determined from the product of the depth in the thickness direction of the slit part 221 under a pressure of 35 gf / cm ² and the bottom area.

Moreover, the absorbent article 1 of the present invention has a total volume of the absorber 22 of 50,000 mm ³ or more and 250,000 mm ³ or less under a pressure of 35 gf / cm ² assuming that the absorbent article 1 is worn. it is preferred, more preferably 80,000 ³ or more 220,000mm is ³ or less, and further preferably 90,000Mm ³ or more 180,000Mm ³ or less. Thereby, the fall of the stability of the shape of the absorber 22 by the slit part 221 can be prevented, and it can be set as the absorbent article 1 excellent in the shape retention property of the absorber 22. FIG.

Moreover, as for the absorbent article 1 of this invention, the ratio of the total volume of the slit part 221 with respect to the total volume of the absorber 22 under pressure of 35 gf / cm < ² > assumed at the time of wear of the absorbent article 1 is 2.5. % To 7.5%, more preferably 3.5% to 6.5%, and still more preferably 4.0% to 6.0%. Thereby, the deterioration of the stability of the shape of the absorbent body 22 by the slit portion 221 can be prevented during wearing of the absorbent article 1 or after absorption of body fluid during wearing, and the shape retention of the absorbent body 22 is excellent. In addition, the absorbent article 1 can be made excellent in absorption performance such as diffusibility, absorption speed, and liquid return amount.

  The longitudinal dimension of the slit portion 221 in the absorbent body 22 of the absorbent article 1 of the present invention is preferably 60 mm or more and 180 mm or less, more preferably 70 mm or more and 165 mm or less, and 80 mm or more and 150 mm or less. Is more preferable. Moreover, it is preferable that the dimension of the width direction in the absorber 22 of the absorbent article 1 of this invention is 5 mm or more and 12 mm or less, It is more preferable that it is 5 mm or more and 10 mm or less, It is further that it is 5 mm or more and 8 mm or less. preferable. Thereby, it is easier to secure a path through which the body fluid diffuses in the absorbent body 22, excellent in absorption performance such as diffusibility, absorption speed, and liquid return amount, and the stability of the shape of the absorbent body 22 by the slit portion 221 is reduced. It is easy to prevent and it can be set as the absorbent article 1 excellent in the shape retention of the absorber 22. FIG.

((Slit section area))
As shown in FIG. 3, the slit portion 221 in the absorbent body 22 of the absorbent article 1 of the present invention has a slit section 221 with respect to the cross-sectional area of the crotch section of the absorbent body 22 in the width direction cross section of the crotch section 1 b of the absorbent body 22. The ratio of the slit cross-sectional area is preferably 10% or more and 25% or less, more preferably 12% or more and 23% or less, and further preferably 15% or more and 20% or less. Here, the crotch portion 1b of the absorbent body 22 is easily subjected to a load such as pressure due to movement of the wearer's leg or the like during the wearing of the absorbent article 1 or after absorption of the body fluid during the wear. In this region, breakage, cracking, etc. are likely to be a problem and are important for the stability of the shape of the absorber 22. Furthermore, the crotch portion 1b of the absorbent body 22 is located in the vicinity of the local area where the body fluid is discharged and is also an area that is important for the absorption performance. Therefore, by setting the ratio of the slit section sectional area of the slit section 221 to the crotch section sectional area of the absorber 22 within the above numerical range, the shape retention of the absorber 22 is achieved when the crotch section 1b has the slit section 221. In addition, the absorbent article 1 can be made excellent in absorbability and has excellent absorption performance such as diffusibility, absorption speed, and liquid return amount.

The slit portion 221 in the absorbent body 22 of the absorbent article 1 of the present invention, in the width direction cross section of the absorbent body 22, the crotch part sectional area of the absorbent body 22, is preferably 250 mm ² or more 450 mm ² or less, more preferably 270 mm ² or more 430mm ² or less, and more preferably 290 mm ² or more 410 mm ² or less.

Moreover, it is preferable that the slit part 221 in the absorbent body 22 of the absorbent article 1 of the present invention has a slit part cross-sectional area of the slit part 221 of 25 mm ² or more and 110 mm ² or less in the cross section in the width direction of the absorbent body 22. more preferably 30 mm ² or more 105 mm ² or less, and more preferably 35 mm ² or more 100 mm ² or less.

[Absorption rate]
The absorbent article 1 of the present invention preferably has an absorption rate of 60 seconds or less, and more preferably 30 seconds or less. Thereby, it can be set as the absorbent article 1 excellent in the absorption speed | velocity | rate which the absorber 22 can absorb a bodily fluid quickly.

  The absorption rate of the absorbent article 1 of the present invention is measured by the following method.

  A crotch portion 1b of the absorbent body 22 in the absorbent article 1 with a measuring jig having an inner diameter of 30 mm opened in the center of a cylinder having an outer diameter of 80 mm and a weight of 2 kg with the top sheet 21 facing upward. Is placed on the center in the longitudinal direction and width direction, and 50 ml of physiological saline (temperature 36 ± 3 ° C.) is dropped from the upper hole, and the time when the physiological saline comes into contact with the top sheet 21 is the starting point. The time is measured with the end point of the time when the physiological saline is completely sucked into the circumference of the central circle, and the rate is taken as the absorption rate.

[Liquid return amount]
The absorbent article 1 of the present invention preferably has a liquid return amount of 1.5 g or less, and more preferably 0.5 g or less. Thereby, the absorbent body 22 that has absorbed the body fluid can retain the body fluid absorbed, and the absorbent article 1 having an excellent liquid return amount can be obtained.

  The liquid return amount of the absorbent article 1 of the present invention is measured by the following method.

300 ml of physiological saline (temperature 36 ± 3 ° C.) is injected into the center of the absorbent article 1 and 10 sheets of filter paper (No. 2 filter paper manufactured by ADVANTEC, diameter 55 mm) whose weight has been measured in advance after 10 minutes have been injected. And put a 687 g weight on the filter paper (pressure: 35 gf / cm ² ). One minute after placing the weight, the weight of the filter paper is measured, and the weight difference (g) of the filter paper before and after the test is taken as the liquid return amount. The liquid return amount is an average value obtained for N = 10 samples. The smaller the liquid return amount, the better the absorption performance.

[Method of manufacturing absorbent article]
A well-known method can be employ | adopted for the manufacturing method of the absorbent article 1. FIG. For example, (A) a process of forming absorbent mats by stacking absorbent fibers together with a superabsorbent polymer to form absorbent bodies 22, (B) a hot melt adhesive, etc., for topsheet 21 and three-dimensional gather 24 (C) a step of applying a hot-melt adhesive on the inner side of the top sheet 21, the three-dimensional gather 24, and the back sheet 23, and (D) in the assembly drum, on the upper part of the absorber 22. The top sheet 21 is placed under the absorber 22 and the back sheet 23 is disposed, and the constituent members are fixed and integrated. (E) The semi-finished product of the absorbent article 1 is cut into product dimensions by a cutter device. The manufacturing method etc. which have the process of cutting off the absorbent article 1 of these can be mentioned. And when shape | molding the absorber 22 of the absorbent article 1 in this invention, after providing the predetermined slit in the crotch part 1b of the absorber 22 previously cut | judged to the predetermined shape, top sheet | seat 21 is formed in upper part. Alternatively, the back sheet 23 may be disposed in the lower portion, and the respective constituent members may be fixed and integrated.

Moreover, a well-known method can be employ | adopted for the manufacturing method in the case of using the absorbent article 1 as a tape stop paper diaper. For example, the absorber 22 formed in a predetermined shape including the slit 221, the top sheet 21 in which the three-dimensional gather 24 is disposed, and the back sheet 23 in which the waist gather 28, the leg gather 27, and the side panel 261 are disposed are integrated. After folding, the whole is cut into a predetermined length and manufactured. As a means for integrating the members, a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, or the like can be used. It is preferable that the fastening tape 262 is bonded to the back sheet 23 in advance by bonding the fastening means 263 to a base material constituting the fastening tape 262, cutting the fastening tape 262 into a predetermined shape. In storing the absorbent article 1 in a package or the like, the absorbent article 1 may be folded in the longitudinal direction Y and the width direction X.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, this invention is not limited to the Example shown below at all.

<Example 1>
(Production of absorbent articles)
6 g of fluff pulp and 6 g of superabsorbent polymer, which were pulverized and pulverized, were placed in the crotch part with two slits with a length of 75 mm and a width of 5 mm, and the whole was piled up to a length of 300 mm and a width of 100 mm. An absorber was prepared. The absorbent body is wrapped with a carrier sheet, laminated together with a top sheet and a back sheet, and a pair of three-dimensional gathers for preventing side leakage are formed to produce an absorbent article having a length of 360 mm and a width of 280 mm. A sample was used. Note that the top sheet, using a air-through nonwoven fabric (basis weight 18 g / ^{m 2),} the backsheet, with a breathable polyethylene film (basis weight 18g / ^{m 2).} The absorption rate, liquid return amount, and shape retention of the resulting absorbent article were measured and evaluated according to the following.

(Absorption rate)
According to the above-mentioned method, the absorption rate of the absorbent article is measured. From the measurement results, when the absorption rate is 20 seconds or less, “◎”, when it is 21 seconds or more and 40 seconds or less, “◯”, when it is 41 seconds or more Was marked “x”.

(Liquid return amount)
According to the above-mentioned method, the liquid return amount of the absorbent article is measured, and from the measurement result, when the liquid return amount is 0.5 g or less, “◎”, when 0.6 g or more and 1.5 g or less, “◯”, When it was 1.6 g or more, it was set as “x”.

(Shape retention)
20 panelists were asked to wear absorbent articles for 4 hours in a row, and then evaluated whether abnormalities such as twists and defects occurred in the absorbent body of the absorbent articles. “◎” when the number of respondents who reported abnormal shape is 2 or less in 20 people, “○” when 3 to 5 in 20 people, and “×” when 6 or more in 20 people It was.

  Table 1 summarizes the structure of the manufactured absorbent article of Example 1 and the measurement results and evaluation of the absorption rate, the liquid return amount, and the shape retention.

<Examples 2 to 4>
The absorbent articles of Examples 2 to 4 were produced by a production method basically similar to the production method of the absorbent article of Example 1, and the parts related to the configuration different from the absorbent article of Example 1 Table 1 summarizes the measurement results and evaluation of absorption rate, liquid return amount, and shape retention.

<Comparative Examples 1 to 4>
The absorbent articles of Comparative Examples 1 to 4 were produced by basically the same production method as that for the absorbent articles of Examples 1 to 4, and the parts related to different configurations, the absorption speed, the liquid return amount, and the like. Table 1 summarizes the measurement results and evaluation of shape retention.

As shown in Examples 1 to 4, in an absorbent article having a plurality of linear slit portions penetrating the absorbent body in the thickness direction of the absorbent body, 35 gf / cm ² is assumed when the absorbent article is worn. under pressure, the total volume of the slit portion by a 2000 mm ³ or more 15000 ³ or less, diffusibility, excellent absorption performance of the absorption rate and the liquid return amount, and shape of the absorber to the pressure and the like according to body absorber Stability was made favorable and it was able to be set as the absorbent article excellent in the shape retention of an absorber.

On the other hand, under the pressure of 35 gf / cm ² assuming that the absorbent article is worn, the absorbent article of Comparative Example 1 in which the total volume of the slit part is less than 2000 mm ³ is too small for the total volume of the slit part. The diffusibility deteriorated and the absorption performance of the absorption rate and the liquid return amount was inferior.

In addition, the absorbent article of Comparative Example 4 in which the total volume of the slit part exceeded 15000 mm ³ under a pressure of 35 gf / cm ² assuming the wearing of the absorbent article was diffused because the total volume of the slit part was too large. The properties improved, but the shape retention of the absorber was inferior.

Further, under a pressure of 35gf / cm ² was assumed when wearing the absorbent article, although the total volume of the slit portion is the 2000 mm ³ or more 15000 ³ or less, the ratio of the total volume of the slit portion to the total volume of the absorber The absorbency of Comparative Example 2 is less than 2.5%, and the ratio of the cross-sectional area of the crotch part to the cross-sectional area of the absorber of the crotch part is less than 10% in the cross-section in the width direction of the crotch part of the absorbent article Since the article has an excessively small volume of the slit portion with respect to the entire absorbent body, the diffusibility is deteriorated, and the absorption performance of the absorption rate and the liquid return amount is not improved.

Further, under a pressure of 35gf / cm ² was assumed when wearing the absorbent article, although the total volume of the slit portion is the 2000 mm ³ or more 15000 ³ or less, the ratio of the total volume of the slit portion to the total volume of the absorber Absorbent article of Comparative Example 3 in which the ratio of the cross-sectional area of the slit part of the crotch part to the cross-sectional area of the absorber of the crotch part exceeds 25% in the widthwise cross section of the crotch part of the absorbent article exceeding 7.5% Since the volume of the slit part with respect to the whole absorber was too large, the absorption performance such as diffusibility, absorption speed and liquid return amount was improved, but the shape retention of the absorber was inferior.

DESCRIPTION OF SYMBOLS 1 Absorbent article 1a Abdominal side part 1b Crotch part 1c Back side part 21 Top sheet 22 Absorber 221 Slit part 23 Back sheet 24 Three-dimensional gather 241 Three-dimensional gather elastic member 242 Three-dimensional gather sheet 25 Carrier sheet 26 Side flap 261 Side panel 262 Fastening tape 263 Fastening means 264 Knob margin 27 Leg gather 28 Waist gather

Claims (3)

An absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet,
The absorber comprises a ventral part, a dorsal part, and a crotch part between the ventral part and the dorsal part,
At least the crotch portion of the absorber is provided with a plurality of linear slit portions extending in the longitudinal direction of the absorber,
The slit portion does not include fluff pulp and superabsorbent polymer, and penetrates the absorber in the thickness direction of the absorber,
Wherein under a pressure of 35gf / cm ² was assumed when wearing the absorbent article, the total volume of the slit portion, the absorbent article is 2000 mm ³ or more 15000 ³ below. The ratio of the total volume of the slit portion to the total volume of the absorber is 2.5% or more and 7.5% or less under a pressure of 35 gf / cm ² assuming the wearing of the absorbent article. Item 10. An absorbent article according to Item 1.   The absorptivity of Claim 1 or 2 whose ratio of the slit part cross-sectional area of the said crotch part with respect to the said crotch part cross-sectional area is 10% or more and 25% or less in the width direction cross section of the said crotch part of the said absorbent article. Goods.

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