JP2011120654A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article capable of efficiently utilizing the entire surface of an absorber for liquid absorption by reducing a wet feeling felt by a wearer during excretion and accelerating liquid diffusion in the longitudinal direction of the absorber while preventing side leakage, in the absorbent article to which the absorber having the longitudinal direction and a width direction orthogonal to it is applied. <P>SOLUTION: The absorbent article 10 includes the absorber 3 having the longitudinal direction and the width direction orthogonal to it. A liquid permeable intermediate sheet 4 is disposed between a top sheet 1 and the absorber 3, the intermediate sheet 4 is three-dimensionally shaped so as to form many groove parts 41 extending in the longitudinal direction of the absorber 3 and opening to the side of the top sheet 1, and the entire area on the skin contact surface side is covered with the top sheet 1. The intermediate sheet 4 is provided with a lowly liquid permeating area along the longitudinal direction of the absorber 3 and a highly liquid permeating area of higher liquid permeability. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an absorbent article.

  In absorbent articles such as sanitary napkins, disposable diapers, and incontinence pads, an absorbent body having a longitudinal direction and a width direction that is shorter than that and perpendicular to the longitudinal direction is often applied. By all means, the body fluid tends to spread to the edge in the width direction before it sufficiently diffuses in the product longitudinal direction. Therefore, when the excretion of body fluid is large, leakage from the end in the width direction of the absorbent article may occur. Patent Document 1 discloses a sanitary napkin in which a cushion layer made of hydrophobic fibers folded in a bellows shape is arranged on an absorbent body so that the fold line is along the longitudinal direction. The sanitary napkin is provided with an opening in which a top sheet at a position corresponding to the excretion point is cut out, and the cushion layer is in a state of receiving excretory fluid directly. In this way, the cushion layer made of hydrophobic fibers with a groove-like structure in the product longitudinal direction directly receives the excretory fluid, effectively spreading the body fluid in the longitudinal direction without spreading in the product width direction and suppressing side leakage It is said that sufficient absorption performance is realized.

Japanese Utility Model Publication No. 2-39718

However, in the sanitary napkin disclosed in Patent Document 1, the top sheet does not exist at the excretion point, and the cushion layer is composed of hydrophobic fibers. There is a possibility that the body fluid directly touches the wearer's skin and feels numb.
The present invention relates to an absorbent article to which an absorbent body having a longitudinal direction and a width direction orthogonal to the longitudinal direction is applied, and reduces the sensation felt by the wearer at the time of excretion and prevents the side leakage. It is an object of the present invention to provide an absorbent article that can efficiently utilize the entire absorber for liquid absorption by promoting liquid diffusion in the direction.

  In order to solve this problem, the inventors have defined a top sheet that forms a skin contact surface, a back sheet that forms a non-skin contact surface, and a longitudinal direction interposed between the two sheets and a width direction perpendicular thereto. A liquid-permeable intermediate sheet is disposed between the top sheet and the absorbent body, and the intermediate sheet extends in a longitudinal direction of the absorbent body on the top sheet side. Three-dimensionally shaped so as to form an open multi-groove, and the entire area on the skin contact surface side is covered with the top sheet, and the intermediate sheet is along the longitudinal direction of the absorber It has been found that the problem can be solved by introducing a structure having a low liquid permeation region and a high liquid permeation region having higher liquid permeation.

  The absorbent article of the present invention is an absorbent article to which an absorbent body having a longitudinal direction and a width direction perpendicular thereto is applied. The absorbent article reduces the sensation felt by the wearer during excretion and prevents side leakage. By promoting liquid diffusion in the longitudinal direction of the body, there is an effect that the entire absorbent body can be efficiently utilized for liquid absorption.

It is a partial notch perspective view which shows typically the incontinence pad as embodiment of the absorbent article of this invention. It is a top view of the light incontinence pad shown in FIG. 1, and has shown in the state which peeled the surface sheet. It is an expanded sectional view of the III-III line cross section of the light incontinence pad shown in FIG. It is sectional drawing which expanded a part of cross section of FIG. 3 further (however, illustration of a liquid is abbreviate | omitted).

Hereinafter, preferred embodiments of the absorbent article of the present invention will be described with reference to the drawings, taking an incontinence pad as an example.
An incontinence pad 10 according to the embodiment shown in FIG. 1 includes a liquid-permeable top sheet 1 made of a nonwoven fabric or a perforated film, a liquid-impermeable and vapor-permeable back sheet 2, and liquid retention between the two sheets. The absorber 3 is interposed. Here, the outer periphery of the top sheet 1 and the back sheet 2 is firmly joined by a peripheral seal portion, and the internal absorber and the like are sealed. In the incontinence pad of the present embodiment, a liquid-permeable intermediate sheet 4 that is three-dimensionally shaped in a wavy or corrugated shape in cross section is further disposed between the top sheet 1 and the absorber 3. The intermediate sheet 4 is three-dimensionally molded into a structure that forms a plurality of linear groove portions 41 along the product longitudinal direction (direction X), and the top portion of the intermediate sheet is between two adjacent linear groove structures. (Ridge line portion) 6 is formed (see FIGS. 1, 3, and 4). Thus, when receiving the excretion of liquid a ₁ by the structure having a plurality of grooves 41, the liquid diffusion a ₂ in the product longitudinal direction (direction X) is promoted, while the diffusion a ₃ in the width direction is It is possible to moderately prevent the leakage from the end (see FIGS. 1 and 2). And since the skin contact surface side of the intermediate sheet 4 of this embodiment is entirely covered with the top sheet 1, it is difficult to give the wearer a sensation due to liquid diffusion in the longitudinal direction. In addition, the intermediate sheet 4 is made of a flexible material and has an uneven surface, so that the intermediate sheet 4 is soft with a line and corresponds to the skin, and its cushioning property provides a good feeling of wearing.

  In this specification, “skin contact surface” means a surface that comes into contact with the skin of the wearer, and “non-skin contact surface” means a surface that does not come into contact with the wearer's skin. “Surface side” refers to the part / surface closer to the wearer's skin, and “non-skin contact surface side” refers to the part / surface farther from the wearer's skin. It is a term. The longitudinal direction is a direction having a length in plan view of the member or product, and typically refers to a direction along the long side of the rectangle. The width direction is the direction of the member width which is orthogonal to the longitudinal direction and shorter than this. In the present embodiment, the longitudinal direction of the absorbent body coincides with the longitudinal direction of the product (incontinence pad). However, in the present invention, the absorbent article has a form in which the longitudinal direction of the absorbent body does not coincide with the longitudinal direction of the product. There may be.

  The groove portion 41 provided in the intermediate sheet 4 has a liquid permeability of a partial region (hereinafter referred to as a low-permeability region [L]) along the longitudinal direction, and other peripheral regions (hereinafter referred to as a high liquid-permeability region [ H])). By doing so, the liquid is easily diffused along the low transmission region [L]. Here, “liquid permeability is made lower than other areas” typically means that the whole is liquid permeable, but (i) a low permeable area (partial area) [L] When the liquid permeation rate is slower than that of the high liquid permeation area (surrounding area) [H], (ii) the high liquid permeation area (surrounding area) [H] is liquid permeable, but the low liquid permeation area (one (Partial area) [L] means water repellency, poor liquid permeability or liquid impermeability.

  From the viewpoint of effectively diffusing the liquid in the longitudinal direction, the low transmission region [L] is preferably provided in the bottom portion 5 and / or the trough portion 4c in the vicinity thereof. Moreover, in addition to these, you may be provided in the peak part 6a of the top part 6 and / or its vicinity alone. In the present embodiment, the low transmission region [L] is provided on both the bottom portion 5 and the top portion 6 (see the satin pattern portion in FIG. 4). By the low liquid permeation area [L] provided in the bottom part 5, the excretory liquid that has permeated the top sheet 1 is appropriately accumulated in the groove part 41 (see liquid 11), and the product longitudinal direction (X Direction) (see FIG. 3), and the liquid transfer diffusion property in the longitudinal direction is further improved. On the other hand, the low-permeability region [L] provided in the top portion 6 is useful for quickly guiding the excretory fluid that has permeated through the top sheet toward the bottom portion 5. Therefore, from the viewpoint of enhancing the diffusibility of the excretory liquid along the product longitudinal direction X, it is sufficient to provide the low transmission region [L] at the bottom portion 5, but the effect can be further enhanced by providing the top portion 6. It is easy to be exhibited and is preferable. 3 schematically shows the liquid (liquids 11 and 12) accumulated in the groove portion 41 and the groove space portion 42, it is shown as a model in consideration of the convenience of explanation. The description is not intended to limit the invention.

  Further, a low transmission region [L] can also be provided in the wall portion 4 b of the intermediate sheet in the groove portion 41. In this case, the excretory fluid that has passed through the top sheet 1 is less likely to pass through the wall portion 4 b in the groove portion 41, so that the excretory fluid is easily diffused along the groove portion 41 in the product longitudinal direction X. This effect is more likely to be exhibited in the case where the structure is such that the wall 4b of the intermediate sheet stands upright at an obtuse angle with respect to the bottom 5, as shown in FIG. . The range of the angle θ is not particularly limited, but is preferably set to 45 to 85 ° in consideration of effective liquid diffusibility.

Moreover, from the viewpoint of suppressing the liquid 12 filled in the groove space 42 between the intermediate sheet and the absorber from returning to the top sheet 1 side, the low transmission region [L] provided in the wall 4b. The range of 10 to 70% of the height d ₁ (FIG. 3) of the wall as viewed from the bottom 5 side (may include some peaks 4a or valleys 4c in relation to the form shown in FIG. 4). Is preferably provided. At this time, by reducing the liquid permeability of a part of the wall portion 4b instead of the whole region, the fluid is absorbed by the absorber before the groove portion 41 is filled with the body fluid, or the body fluid is absorbed in the adjacent groove portion 41. This is preferable because it accumulates and the liquid flow to the top sheet side can be effectively suppressed. If the bottom 5 side providing the low transmission region [L] is either the wall portion 4b is not provided with the low permeability region [L], at best wall height d ₁ of the bottom 5 of the following 10% side range ( It may be provided at a part of the valleys 4c). In FIG. 4, the low liquid permeation region [L] of the bottom 5 and the top 6 is shown by a satin pattern, but the low liquid permeation region [L] of the wall 4 b is not shown.

<Measurement method of liquid permeability>
In the present invention, the liquid permeability means a value measured by the following procedure unless otherwise specified.
When 10 mL of 0.9 mass% physiological saline is dropped on the measurement sample, the time until the droplet disappears is measured at 10 locations. The average value is used as an index of liquid permeability. Therefore, the smaller this value, the better the liquid permeability (the faster the transmission speed). At this time, as the bottom surface area of measuring the liquid permeability, basis weight of the pulp / polymer was placed on the absorber on which each consist of ^{(150g / m 2) / (} 150g / m 2), 37g / cm 2 The sample is allowed to stand for 5 minutes under the above loading conditions.

  In the intermediate sheet 4 suitably used in the present embodiment, the low transmission region has an average time of 5 seconds or more after dropping after the dropping by the measurement method, and the surrounding region drops after dropping. It is preferable that the average time until disappearance is less than 5 seconds. When the low-permeability region [L] in the intermediate sheet 4 is provided at a plurality of locations among the valley portion 4c, the peak portion 4a, and the wall portion 4b, the liquid permeability may be different at each portion. For example, by increasing the liquid permeability in the order of the valley 4c (bottom 5), peak 4a (top 6), and wall 4b, the excretory liquid that has passed through the top sheet 1 is not easily transmitted at the bottom, and the product longitudinal direction Although it is diffused along X, it is easy to permeate from the top, so it is convenient when the amount of excretory fluid is large. On the other hand, since the excretory liquid 12 permeate | transmitted to the groove space part 42 in a wall via the wall part 4b becomes a structure which is hard to leak to a wearer side through a top part, it is hard to give a wearer a wet feeling.

  As a means for lowering the liquid permeability of the low liquid permeable region (partial region) [L] of the intermediate sheet 4, a method of joining the intermediate sheet to the absorbent body by means of groove-like heat embossing, a hydrophobic adhesive, Examples thereof include a method of bonding the intermediate sheet to the absorber, and a method of applying a hydrophobic agent. Examples of the hydrophobic agent include surfactants such as fluorine compounds, paraffin waxes, and long chain (for example, alkyl chain length of 18 or more) alkyl sulfate metal salts. Further, as a method of relatively reducing the liquid permeability of a partial region, there is a method in which the constituent fibers of the intermediate sheet 4 are made hydrophobic or water repellent and a hydrophilizing agent is applied to a portion other than the partial region. Can be mentioned. Examples of the hydrophobic or water-repellent fiber include fibers such as polyester, polyethylene, and polypropylene. Examples of the hydrophilizing agent include hydrophilic surfactants. Specifically, anionic surfactants such as nonionic surfactants having an HLB of 7 or more, alkyl sulfates having an average alkyl chain length of 16 or less, and alkyl ether sulfates. Etc. can be used suitably.

  From the viewpoint of suppressing liquid diffusion to the end in the longitudinal direction of the product and improving anti-moisture performance, it is preferable that the intermediate sheet 4 is disposed in the center smaller than the absorber 3 in plan view. In other words, in the product longitudinal direction (X direction), the front and rear ends of the intermediate sheet 4 are the regions inside the product longitudinal direction front and rear ends of the absorbent body 3 and the center in the width direction. It is preferable that it exists in a part.

  The intermediate sheet 4 is a single sheet whose cross section is shown in FIGS. 3 and 4 from the viewpoint of effectively preventing cost and liquid flow from the top sheet side, and the groove space 42 in the wall is hollow. It is preferable to be configured to have a shape structure. As an example of this modification, the groove space portion 42 may be filled with fibers. However, as shown in the drawing, a larger volume of bodily fluid is formed by a single sheet and having a hollow structure. Even when the urine is excreted, the body fluid is temporarily held in the groove 41 (liquid 11) and the groove space 42 (liquid 12), so that liquid return to the top sheet and liquid leakage can be prevented more effectively. Is done.

It is preferable that the wall 4b includes an even higher ultra-high liquid permeation area in the high liquid permeation area (surrounding area). In other words, the intermediate sheet may have three regions: a low liquid permeation region (partial region) [L], a high liquid permeation region (surrounding region) [H], and an ultra high liquid permeation region [S]. . The ultra-high liquid permeation region [S] is a region extending from the top 6 side or the bottom 5 side of the height d ₁ of the intermediate sheet to 10 to 30% (may be present in the valley 4b). Is preferred. By having the ultra-high liquid permeation region [S] in this way, before the groove portion 41 is filled with the body fluid, it moves to the groove space portion 42 and is further absorbed and held in the absorbent body 3, thereby drawing in the liquid more quickly and effectively. In addition, liquid return to the top sheet side can be suppressed. Examples of the method of providing the ultra-high liquid permeable region [S] in the intermediate sheet include a method of providing holes in the intermediate sheet, a method of applying a hydrophilic surfactant, and the like. As the hydrophilic surfactant, anionic, cationic, amphoteric and nonionic surfactants having various molecular weights are preferably used alone or in combination.

  The liquid permeability relationship between the intermediate sheet 4 and the top sheet 1 is not particularly limited. From the viewpoint of more effectively drawing out the liquid diffusing action and the anti-reverse action of the three-dimensionally shaped intermediate sheet 4, It is preferable that the liquid permeability of the top sheet 1 is lower than the liquid permeability of the liquid permeable region [H].

  The degree of liquid permeability of each sheet and each part thereof is not particularly limited, and can be appropriately adjusted in consideration of the liquid diffusion action and the anti-reverse action. Taking an example in consideration of members, usage conditions, amount of excretory fluid, etc. in a general incontinence pad, the liquid permeability Ts of the ultra-high liquid permeability area [S] and the liquid permeability of the high liquid permeability area [H]. The order of the property Th, the liquid permeability Tl of the low liquid permeability region [L], and the liquid permeability Tt of the top sheet is preferably Ts> Th> Tt> Tl.

The intermediate sheet 4 is preferably joined to the absorber 3 from the viewpoint of improving the liquid drawing force toward the absorber 3 side. Examples of the bonding method include a method of bonding with hot embossing or an adhesive. The adhesive is preferably hydrophobic, and for example, SBS, SEBS, olefin hot melt, etc. can be used. The intermediate sheet 4 has a basis weight of preferably 10 to 100 g / m ² and more preferably 15 to 50 g / m ² from the viewpoint of cost and required tensile strength. From the viewpoint of preventing crushing strength against body pressure and liquid leakage, the intermediate sheet 4 is preferably ₁ to 10 mm in height d ₁ from the bottom to the top, and 3 to 8 mm from the viewpoint of wearing feeling when worn. More preferably it is. Furthermore, it is preferable that the intermediate sheet 4 has a compression recovery property from the viewpoint of preventing the uneven shape from being excessively deformed by body pressure. Specifically, the intermediate sheet 4 preferably has a compression recovery rate of 10% or more, particularly 30% or more. Examples of the intermediate sheet 4 having a desired compression recovery property include a method using a porous polyurethane sheet or a bulky fiber nonwoven fabric.

<Compression recovery rate>
In this specification, the compression recovery rate means a value measured by the following procedure unless otherwise specified.
Based on the following formula based on the compression work Wc (gf · cm / cm ² ) and the compression recovery work Wc ′ when the sheet is compressed by applying a load of 50 gf / cm ^{2 at} a stroke speed of 50 times / min. calculate. For example, it can be measured using KES-TB3 (trade name) manufactured by Cartec Corporation.
Compression recovery rate (%) = (Wc ′ / Wc) × 100 Equation 1

The form of the three-dimensional shaping of the intermediate sheet is not particularly limited as long as it forms a plurality of grooves, and even if a single sheet is bent as in this embodiment, a thick sheet-like material is used. May be partially compressed or may be subjected to a process of excising the groove. The thickness d ₁ of the three-dimensionally shaped intermediate sheet is not particularly limited, but is preferably 1 to 10 mm in consideration of the dimensions of a general incontinence pad. The relationship with the width d ₂ of one groove is not particularly limited, but the ratio of d ₁ and d ₂ (d ₁ / d ₂ ) is preferably 0.5-2. In terms of the relationship with the thickness d _{3 of the} absorber, this is not particularly limited, but the ratio (d ₁ / d ₃ ) of both is preferably 0.1 to 7.
As described above, the arrangement position of the intermediate sheet is preferably in the center in plan view with respect to the absorber. The dimensional relationship is not particularly limited, but specifically, the length s _{2 of the} intermediate sheet (see FIG. 2) is preferably 30 to 90% with respect to the length s ₁ of the absorber, More preferably, it is 50 to 70%. The width r _{2 of the} intermediate sheet is preferably 30 to 90%, more preferably 50 to 70% with respect to the width r _{1 of the} absorber.

  Furthermore, in the above-described embodiment, the case where the low liquid permeable region [L] is provided in the entire longitudinal direction of the bottom portion 5 and the top portion 6 has been described. However, the present invention is not limited to these embodiments. It may be provided only in the excretion area in the direction. Moreover, as a shape of the low liquid permeation | transmission area | region [L], you may provide intermittently in a longitudinal direction other than what is provided in a linear form, and may provide in a spiral shape and a zigzag shape.

Below, the material suitably employ | adopted for the light incontinence pad of the said embodiment is demonstrated.
The material constituting the intermediate sheet 4 is not particularly limited as long as it can form a groove-like structure and can impart liquid permeability to a part of the region. For example, paper, nonwoven fabric, film, foam, etc. Can be used. In the case of fiber aggregates and films such as non-woven fabrics, it becomes a sheet having elasticity when made of thermoplastic elastomers such as styrene, urethane, olefin, ester, and metallocene-catalyzed ultra-low density polyethylene. Is preferred. In the case of a foam, an elastic sheet such as foamed urethane or foamed polyethylene is preferable. Of these, ester aggregates and metallocene-catalyzed ultra-low density polyethylene fiber aggregates, films, or foamed urethane sheets are particularly preferred from the viewpoints of liquid permeability and elasticity.

  The top sheet 1 is preferably a hydrophilic thermal bond nonwoven fabric from the viewpoint of promptly absorbing the excreted body fluid and transmitting it to the absorbent body, and from the viewpoint of good touch, and particularly preferably an air-through nonwoven fabric. The top sheet 1 is preferably a thermoplastic resin fiber that has been subjected to a hydrophilic treatment, and the fiber is a fiber that has undergone a three-dimensional crimp such as a secondary crimp or a tertiary crimp. Specifically, polyethylene, polypropylene, polyester, nylon, and composite fibers thereof are prepared, and various hydrophilizing agents are applied at a stage before cutting into a predetermined length to form staples. Hydrophilic agents include various alkyl sulfonates represented by α-olefin sulfonates, acrylates, acrylate / acrylamide copolymers, ester amides, ester amide salts, polyethylene glycol and derivatives thereof, water-soluble Hydrophilic treatment with a hydrophilizing agent known to those skilled in the art, such as a reactive polyester resin, various silicone derivatives, various sugar derivatives, and mixtures thereof, can be used.

The back sheet 2 may be a moisture permeable film alone, a laminate of a film and a nonwoven fabric, or a water-repellent nonwoven fabric (such as SMS or SMMS). In order to realize a leak-proof layer that sufficiently exhibits the performance of moisture discharge related to the present invention and does not ooze out moisture, the moisture permeability should be in the range of 0.7 to 3.0 g / 100 cm ² hr. Is preferable, and it is still more preferable that it exists in the range of 1.0-2.5. From the standpoint of sufficiently improving the smoothness, it is most preferably from 1.5 to 2.5. Moreover, when using a moisture-permeable film, in order to be able to use without troubles, such as a tear of a film, a film basic weight is 18-70 g / m < ² >, More preferably, it is 25-60 g / m < ² >.

  The absorbent body 3 is mainly composed of pulp fibers, and particles of the superabsorbent polymer are uniformly mixed and dispersed in the pulp fibers. The absorbent body 3 is formed in the longitudinal direction in the same direction as the longitudinal direction of the incontinence pad, and both ends in the longitudinal direction of the absorbent body 3 are located slightly inside the positions of both longitudinal ends of the incontinence pad. The plan view shape of the absorber 3 as viewed from the top sheet 1 is a substantially rectangular shape in which both end edges in the longitudinal direction are formed in an arc shape. The top sheet 1 and the back sheet 2 extend from both ends of the absorbent body 3 in the longitudinal direction, and are joined to each other at the extended portions. Both side edges of the top sheet 1 are joined to the back sheet 2 on the non-skin contact surface side of the absorber 3.

  In the above embodiment, the configuration of the present invention has been described by taking an incontinence pad as an example. However, the present invention is not limited to this, and the present invention is not limited to this, but the present invention may include other absorbent articles such as panty liners, sanitary napkins, adult absorbent pads, It can be suitably applied to disposable diapers for infants and the like, and has the above-described excellent effects.

1. Top sheet 2. 2. Back sheet Absorber 4. Intermediate sheet 41. Groove part 42. Groove space 4a. Yamabe 4b. Wall 4c. Tanibe 5. Bottom 6. Top 9. Peripheral seal part 10. Incontinence pad

Claims (6)

Absorbent article comprising a top sheet that forms a skin contact surface, a back sheet that forms a non-skin contact surface, and an absorbent body having a longitudinal direction interposed between both sheets and a width direction perpendicular thereto Because
A liquid-permeable intermediate sheet is disposed between the top sheet and the absorbent body, and the intermediate sheet extends in the longitudinal direction of the absorbent body so as to form a multi-groove that opens to the top sheet side. The entire area on the skin contact surface side is covered with the top sheet,
The said intermediate sheet is an absorbent article which has the low liquid permeable area | region along the longitudinal direction of the said absorber, and the high liquid permeable area | region where liquid permeability is higher than this.   The absorbent article according to claim 1, wherein the low-liquid-permeation region of the intermediate sheet is disposed at the bottom of the intermediate sheet that forms the bottom of the groove extending in the longitudinal direction.   The absorbent article according to claim 1 or 2, wherein the low liquid permeation region of the intermediate sheet is disposed on the top of the intermediate sheet existing between the grooves extending in the longitudinal direction.   The absorbent article according to any one of claims 1 to 3, wherein the intermediate sheet is smaller than the absorbent body in a plan view and disposed in the center in the longitudinal direction and the width direction of the absorbent body.   The absorbent article according to any one of claims 1 to 4, wherein at least a bottom portion of the intermediate sheet that forms the bottom of the groove portion is bonded to the absorbent body.   The absorption according to any one of claims 1 to 5, wherein there are a plurality of groove spaces extending in a longitudinal direction of the absorber and opening to the absorber side between the intermediate sheet and the absorber. Sex goods.

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