JP7018296B2 - Absorbent laminates and absorbent articles - Google Patents

Description

The present invention relates to an absorbent laminate used for an absorbent article such as a urine pad (including a light incontinence pad), a menstrual napkin, a disposable diaper, and an absorbent article provided with the absorbent laminate.

Conventionally, an absorbent article having an absorbent body configured to have a water-absorbent resin between sheet members and not to have pulp fibers is known. For example, Patent Documents 1 to 3 disclose an absorbent article having an absorbent laminate in which a plurality of such absorbers are laminated.

Japanese Unexamined Patent Publication No. 2004-313580. Japanese Unexamined Patent Publication No. 2011-136078 JP-A-2015-000236

Since the absorber configured to have the water-absorbent resin between the sheet members and not the pulp fibers does not have the pulp fibers, it can be formed thin while ensuring the absorption capacity. In an absorbent laminate having a plurality of such layer structures, it is possible to increase the absorption capacity according to the number of the layer structures. However, since the water-absorbent resin gels or swells when it absorbs body fluid such as urine, in the absorbent laminate configured in this way, as much as possible of the water-absorbent resin arranged in the absorbent laminate is urine. It is important to secure the diffusivity in the plane direction and the thickness direction of the absorbent laminate so as to contribute to the absorption of the above.

The present invention has been made in view of the above circumstances, and an object thereof is an absorbent laminate having a plurality of absorbent layers having a water-absorbent resin between sheet members and no pulp fibers, and having a high absorption capacity. It is an object of the present invention to provide an absorbent laminate having excellent diffusivity and an absorbent article provided with the absorbent laminate.

The absorbent laminate of the present invention that has been able to solve the above problems is an absorbent laminate that is used for absorbing body fluid and has a longitudinal direction and a width direction; the absorbent laminate is It has an upper absorption layer arranged on the skin surface side and a lower absorption layer arranged on the non-skin surface side; the upper absorption layer and the lower absorption layer each have a water-absorbent resin between the sheet members. It is configured to have no pulp fibers and has a sealing part where the sheet members are joined together and a non-sealing part where the sheet members are not joined together; the upper absorption layer and the lower absorption layer are each in the width direction. It has an end region and a central region located between them on both sides; the upper absorption layer has a sealed portion formed in the end region and a sealed portion and an unsealed portion formed in the central region. In the lower absorption layer, a sealing portion is formed in the end region, an unsealing portion is formed in the central region, and the sealing portion is not formed; in the unsealed portion in the central region of the upper absorption layer. The amount of water-absorbent resin is A (g / m ² ), the amount of water-absorbent resin in the unsealed portion of the central region of the lower absorption layer is B (g / m ² ), and the amount of water-absorbent resin is sealed in the central region of the upper absorption layer. When the amount of the water-absorbent resin in the portion is C (g / m ² ), it is characterized in that it satisfies the relationship of A>B> C.

By constructing the absorbent laminate of the present invention as described above, it is possible to secure a high absorption capacity of the upper absorption layer and the lower absorption layer, and also secure the diffusivity of urine and the like in the absorbent laminate. can do. Therefore, the absorbent laminate of the present invention has excellent absorption performance.

The amount A of the water-absorbent resin in the unsealed portion of the central region of the upper absorption layer is preferably 200 g / m ² or more, and the amount B of the water-absorbent resin in the unsealed portion of the central region of the lower absorption layer is It is preferably 70 g / m ² or more, and the amount C of the water-absorbent resin in the sealing portion of the central region of the upper absorption layer is preferably 50 g / m ² or less.

It is preferable that a water-absorbent resin is arranged in the sealing portion of the central region of the upper absorption layer, and the amount C of the water-absorbent resin in the sealing portion is preferably 5 g / m ² or more and 50 g / m ² or less. .. As a result, while ensuring the permeability of urine or the like in the sealing portion of the central region of the upper absorbing layer, the diffusivity of urine or the like in the sealing portion in the plane direction can be enhanced, and the upper absorbing layer and the lower absorbing layer can be absorbed. It is possible to contribute more of the water-absorbent resin arranged in the layer to absorption.

In the sealing portion, it is preferable that the sheet members are welded to each other. By forming the sealing portion in this way, even if the absorbing layer absorbs water, it becomes easy to maintain the bonding between the sheet members, and it becomes easy to secure the diffusivity of urine or the like in the sealing portion.

The sheet member of the upper absorption layer is preferably made of an air-through nonwoven fabric composed of fibers containing polyethylene resin. If the sheet member of the upper absorption layer is made of such a non-woven fabric, the sheet members can be firmly joined to each other when the sealing portion is formed by heat sealing, ultrasonic welding, or the like, and the sheet member can be firmly bonded to each other. The breaking strength of the material is also high and it is easy to secure it. Therefore, even if the water-absorbent resin arranged in the upper absorption layer absorbs urine or the like and swells, the sealed portion in the central region can be easily maintained.

It is preferable that the basis weight of the sheet member arranged on the skin surface side of the upper absorption layer is larger than the basis weight of the sheet member arranged on the non-skin surface side. By constructing the upper absorption layer in this way, urine or the like received by the absorbent laminate can be quickly drawn into the inside of the upper absorption layer by the sheet member on the skin surface side of the upper absorption layer, and urine can be obtained. It is possible to realize quick absorption of such things.

The water absorption rate of the water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer by the vortex method is preferably 20 seconds or less. As a result, urine or the like is rapidly absorbed and fixed in the upper absorbent layer, and it is possible to suppress the return of urine or the like to the top sheet side in the absorbent article provided with the absorbent laminate.

The present invention also relates to the absorbent laminate of the present invention, the liquid-permeable top sheet provided on the skin surface side of the absorbent laminate, and the liquid impermeable surface provided on the non-skin surface side of the absorbent laminate. Absorbent articles with sex backsheets are also provided. Since the absorbent article of the present invention is provided with the absorbent laminate of the present invention described above, it has excellent absorption performance.

The absorbent laminate of the present invention can secure a high absorption capacity of each absorbent layer, and can also secure the diffusibility of urine and the like in the absorbent laminate. Therefore, the absorbent laminate of the present invention has excellent absorption performance.

An example of the absorbent laminate of the present invention is shown, and a cross-sectional view in the width direction of the absorbent laminate is shown. It shows a partially cutaway plan view of the upper absorption layer of the absorbent laminate shown in FIG. It shows a partially cutaway plan view of the lower absorption layer of the absorbent laminate shown in FIG. An example of the absorbent article provided with the absorbent laminate shown in FIG. 1 is shown, and a plan view of the absorbent article as viewed from the skin surface side is shown. FIG. 4 shows a VV cross-sectional view of the absorbent article shown in FIG.

The absorbent laminate of the present invention is used for absorbing body fluids such as urine, and is provided for absorbent articles such as urine pads (including incontinence pads), disposable diapers, and menstrual napkins. .. The absorbent laminate absorbs and fixes body fluids such as urine received by the absorbent article, and is provided, for example, between the top sheet and the back sheet of the absorbent article.

The absorbent laminate has a skin surface side and a non-skin surface side. The skin surface side means the wearer side when the wearer wears the absorbent article provided with the absorbent laminate, and corresponds to the top sheet side based on the absorbent laminate. The non-skin surface side means the side opposite to the wearer when the absorbent article is worn, that is, the outside, and corresponds to the back sheet side based on the absorbent laminate. Further, the direction extending from the skin surface side to the non-skin surface side is defined as the vertical direction.

The absorbent laminate has a longitudinal direction and a width direction. The longitudinal direction means the direction extending in the anteroposterior direction of the wearer's crotch when the wearer wears the absorbent article provided with the absorbent laminate, and the width direction means the same plane as the absorbent laminate. It means the direction orthogonal to the longitudinal direction. Further, the direction on the surface formed from the longitudinal direction and the width direction is defined as the plane direction.

The shape (planar shape) of the absorbent laminate is not particularly limited. The shape of the absorbent laminate may be appropriately determined according to the intended use, and examples thereof include a rectangle, an hourglass shape, a gourd shape, and a battledore shape.

The absorbent laminate has an upper absorption layer arranged on the skin surface side and a lower absorption layer arranged on the non-skin surface side. The upper absorbent layer is arranged on the skin surface side of the lower absorbent layer, and is arranged on the top sheet side in the case of absorbent articles. The upper absorption layer basically receives urine or the like that has passed through the top sheet and transferred to the absorbent laminate before the lower absorption layer. The upper absorbent layer is preferably arranged on the uppermost side of the absorbent laminate. Further, it is preferable that the upper absorption layer is provided adjacent to the lower absorption layer. The lower absorbent layer is arranged on the non-skin surface side of the upper absorbent layer, and is arranged on the back sheet side in the absorbent article. The lower absorption layer is preferably arranged on the bottom side of the absorbent laminate.

Each of the upper absorption layer and the lower absorption layer is configured to have a water-absorbent resin between the sheet members and not to have pulp fibers. That is, in the upper absorption layer and the lower absorption layer, sheet members are arranged on the skin surface side and the non-skin surface side of each absorption layer, respectively, and a water-absorbent resin is arranged between these sheet members. No pulp fibers are arranged between the members. The presence of pulp fibers inevitably mixed in the upper absorption layer and the lower absorption layer is allowed in the manufacturing process. Since the upper absorption layer and the lower absorption layer have a water-absorbent resin between the sheet members and do not have pulp fibers, they can be formed thin while having a high absorption capacity.

Examples of the water-absorbent resin include polyacrylic acid-based water-absorbent resins such as sodium polyacrylate; and starch-based resins such as starch-acrylonitrile graft copolymer, starch-acrylic acid graft copolymer, and starch-acrylamide graft copolymer. Water-absorbent resin; A polyvinyl alcohol-based water-absorbent resin such as a polyvinyl alcohol crosslinker can be used. As the water-absorbent resin, it is preferable to use a polyacrylic acid-based water-absorbent resin such as sodium polyacrylate because it has a high liquid absorption amount.

The sheet member is liquid permeable and is, for example, a non-woven fabric formed of hydrophilic fibers such as cellulose, rayon and cotton, and polyolefin (for example, polypropylene, polyethylene), polyester (for example, PET) and polyamide (for example, nylon). It is possible to use a non-woven fabric formed of rayon such as the above, in which the surface of the hydrophobic fiber is hydrophilized by a surfactant. Further, as the sheet member, a woven cloth, a knitted cloth, a perforated plastic film or the like may be used. Preferably, a non-woven fabric sheet member (nonwoven fabric sheet) is used as the sheet member.

The basis weight of the sheet member is not particularly limited, but for example, 10 g / m ² or more is preferable, 14 g / m ² or more is more preferable, 17 g / m ² or more is further preferable, 50 g / m ² or less is preferable, and 40 g / m ² or less is preferable. The following is more preferable, and 30 g / m ² or less is further preferable.

The upper absorption layer and the lower absorption layer may be provided with a sheet member on the skin surface side and a sheet member on the non-skin surface side separately. The seat member may be used, and the other side may be used as the non-skin surface side seat member. Further, the sheet member on the non-skin surface side of the upper absorption layer may also serve as the sheet member on the skin surface side of the lower absorption layer. Preferably, the upper absorption layer and the lower absorption layer each have a first sheet member arranged on the skin surface side of each absorption layer and a second sheet member arranged on the non-skin surface side, and the first sheet member. A water-absorbent resin is arranged between the second sheet member and the second sheet member. In this case, each absorption layer is formed independently (separably).

The upper absorption layer and the lower absorption layer each have an end region and a central region in the width direction. The edge region is formed on both sides of each absorption layer in the width direction and is defined as a region including the widthwise edge of each absorption layer. The central region is defined as the region between the end regions of each absorbent layer (ie, between one end region in the width direction and the other end region). In each absorption layer, the length of the central region in the width direction is preferably 60% or more, more preferably 70% or more, more preferably 95% or less, and preferably 90% or less of the length in the width direction of the absorption layer. Is more preferable.

The upper absorption layer and the lower absorption layer each have a sealing portion to which the sheet members are bonded and a non-sealing portion to which the sheet members are not bonded to each other. The sealing portion is formed by joining the sheet members with an adhesive or welding (heat sealing, ultrasonic welding, etc.). The unsealed portion is defined as a portion where the sheet members are not joined to each other in each absorption layer, and the portion other than the sealed portion corresponds to the unsealed portion. A water-absorbent resin may be arranged in at least a part of the non-sealed portion, and the water-absorbent resin may be arranged in the sealed portion as well.

Each of the upper absorption layer and the lower absorption layer has a sealing portion formed in the end region in the width direction, which makes it difficult for the water-absorbent resin to fall off from each absorption layer. The sealing portion is preferably formed over the entire longitudinal direction in the end regions of the upper absorption layer and the lower absorption layer.

In the upper absorption layer, both a sealed portion and a non-sealed portion are formed in the central region in the width direction. By forming the sealing portion in the central region of the upper absorption layer, urine or the like is easily diffused in the plane direction in the sealing portion, and urine or the like permeates the sealing portion and moves to the lower absorption layer. It will be easier. As a result, the diffusibility of urine or the like in the absorbent laminate is enhanced, and urine or the like is rapidly absorbed by the absorbent laminate.

The arrangement of the unsealed portion in the central region of the upper absorption layer is not particularly limited, but the unsealed portion is preferably arranged in a striped shape or an island shape. As a result, in the central region of the upper absorption layer, urine or the like easily diffuses in the plane direction through the sealing portion, and urine or the like permeates through the sealing portion and easily migrates to the lower absorption layer. In the central region of the upper absorption layer, it is preferable that two or more unsealed portions are provided.

When the unsealed portions are arranged in a stripe shape, it is preferable that at least two unsealed portions are provided so as to extend in one direction. When the non-sealed portion is arranged in a striped shape, it is preferable that the sealed portion is also arranged in a striped shape. Preferably, the unsealed portion is arranged in a striped shape extending in the width direction or the longitudinal direction, and more preferably arranged in a striped shape extending in the longitudinal direction. If the unsealed portion is arranged in a stripe shape extending in the longitudinal direction, urine or the like is likely to diffuse in the longitudinal direction of the upper absorption layer. Further, the unsealed portion can be provided in a relatively wide area, and it becomes easy to increase the absorption capacity of the upper absorption layer.

When the non-sealed portions are arranged in an island shape, it is preferable that at least two non-sealed portions are provided and the sealed portions are provided so as to surround the unsealed portions. If the non-sealed portion is arranged in an island shape, urine or the like is likely to diffuse in the plane direction in the sealed portion surrounding the non-sealed portion.

In the central region of the upper absorption layer, it is preferable that the unsealed portion is provided in a striped shape extending in the longitudinal direction. If the non-sealing portion is provided in this way, the diffusivity and permeability of urine and the like are enhanced in the upper absorption layer, and it becomes easy to secure the absorption capacity of the upper absorption layer.

The areas of the sealed portion and the unsealed portion in the central region of the upper absorption layer are not particularly limited, but the area ratio of the sealed portion to the unsealed portion is defined as the area of the sealed portion / the area of the unsealed portion. 5, 95 or more is preferable, 10/90 or more is more preferable, 15/85 or more is further preferable, 70/30 or less is preferable, 60/40 or less is more preferable, and 50/50 or less is further preferable.

On the other hand, in the lower absorption layer, an unsealed portion is formed in the central region in the width direction, and a sealed portion is not formed. This makes it possible to increase the absorption capacity of the lower absorption layer. In addition, urine or the like is less likely to migrate to the non-skin surface side of the absorbent laminate, and in an absorbent article provided with the absorbent laminate, leakage of urine or the like from the back sheet side is less likely to occur. In the central region of the lower absorption layer, since the sealing portion is not formed, the diffusivity of urine or the like in the plane direction may decrease, and the absorption rate of urine or the like in the lower absorption layer may decrease. Since the absorbent laminate has an upper absorbent layer on the skin surface side of the lower absorbent layer, urine or the like returns to the skin surface side of the absorbent laminate even if the absorption rate in the lower absorbent layer decreases. No need to worry.

The central region of the lower absorption layer is preferably provided so as to overlap the sealing portion of the central region of the upper absorption layer, and more preferably, the central region of the lower absorption layer seals the central region of the upper absorption layer. It is provided so as to extend outward in the width direction from the stop portion (outside in the width direction from the sealing portion located most outward in the width direction). The length in the width direction of the central region of the lower absorption layer is preferably 0.7 times or more, more preferably 0.8 times or more, and 0.9 times or more the length in the width direction of the central region of the upper absorption layer. Is more preferable, 1.5 times or less is preferable, 1.3 times or less is more preferable, and 1.2 times or less is further preferable.

It is preferable that the sealing portion maintains the bonding between the sheet members even if each absorbing layer absorbs water. When the absorbent layer absorbs water, the water-absorbent resin arranged between the sheet members swells, and the bonding between the sheet members may be broken at the sealing portion. In this case, it is assumed that the water-absorbent resin will fall off from each absorption layer and the diffusivity of urine or the like in the sealing portion will decrease. Therefore, it is preferable that the sealing portion maintains the bonding between the sheet members even if the absorbing layer absorbs water. In addition, in order to form the absorption layer in this way, it is preferable that the sheet members are welded to each other in the sealing portion of each absorption layer.

When the sheet members are welded to each other at the sealing portion, it is preferable that the sheet members are partially welded at the sealing portion. That is, it is preferable that the sealing portion is provided with a welded portion in which the sheet members are welded together and a non-welded portion in which the sheet members are not welded to each other. By providing the welded portion and the non-welded portion in the sealed portion in this way, the sheet members are firmly bonded to each other in the welded portion, and the permeability of urine or the like is enhanced in the non-welded portion. Further, instead of the welded portion and the non-welded portion, a strongly welded portion in which the sheet members are strongly welded and a weakly welded portion in which the sheet members are weakly welded may be provided. The welded portion and the non-welded portion, or the strongly welded portion and the weakly welded portion can be formed by heat-sealing or ultrasonic welding the sheet members in a predetermined pattern.

In the upper absorption layer and the lower absorption layer, it is preferable that the water-absorbent resin is fixed to the sheet member by an adhesive. That is, it is preferable that an adhesive is applied to the sheet member of each absorbent layer to provide an adhesive layer, and the water-absorbent resin is fixed to the sheet member by the adhesive layer. The adhesive layer may be provided on at least one of the skin surface side sheet member and the non-skin surface side sheet member, but preferably, the adhesive layer is provided on both sheet members. The water-absorbent resin may be at least partially fixed to the adhesive layer, and for example, the water-absorbent resin in contact with the adhesive layer may be fixed to the adhesive layer. If the water-absorbent resin is fixed to the sheet member by the adhesive layer, it becomes difficult for the water-absorbent resin to move between the sheet members before the water-absorbent resin is absorbed, and the absorption capacity of urine or the like in the absorption layer is secured. It will be easier. Even after the water-absorbent resin is absorbed, the gelled water-absorbent resin is less likely to move between the sheet members, and as a result, the water-absorbent resin becomes lumpy and less likely to give the wearer a sense of discomfort.

The adhesive layer preferably fixes the water-absorbent resin and does not inhibit water absorption or swelling due to the water-absorbent resin. As a method for forming the adhesive layer, a curtain spray method, a spiral coating method, an omega coating method, a coater method or the like may be adopted.

Examples of the adhesive used for the adhesive layer include rubber-based adhesives such as natural rubber-based, butyl rubber-based, and polyisoprene; styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer. (SBS), styrene-ethylene-based elastomers such as styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS); ethylene-vinyl acetate copolymer (EVA); polyolefin-based Elastomers, polyolefin waxes and the like can be used. Only one kind of these adhesives may be used, or two or more kinds thereof may be used in combination. Of these, it is preferable to use a rubber-based adhesive or a styrene-based elastomer.

An example of the structure of the absorbent laminate will be described with reference to FIGS. 1 to 3. FIG. 1 shows a cross-sectional view in the width direction of the absorbent laminate, FIG. 2 shows a partially cutaway plan view of the upper absorption layer, and FIG. 3 shows a partially cutaway plan view of the lower absorption layer. Arrows x, y, and z represent the width direction, the longitudinal direction, and the vertical direction of the absorbent laminate, respectively. In the vertical direction z, z1 represents the skin surface side and z2 represents the non-skin surface side. FIGS. 1 to 3 show an example of an absorbent laminate in which the non-sealed portions of the upper absorbing layer are arranged in a stripe shape, but the arrangement and size of the sealed portions and the unsealed portions are appropriately adjusted. It is possible, and the size and arrangement of the upper absorption layer and the lower absorption layer can be adjusted as appropriate.

The absorbent laminate 10 has an upper absorption layer 11 arranged on the skin surface side z1 and a lower absorption layer 21 arranged on the non-skin surface side z2. The upper absorption layer 11 has a water-absorbent resin 13 between the sheet members 12 and is configured not to have pulp fibers, and the lower absorption layer 21 has a water-absorbent resin 23 between the sheet members 22 and pulp. It is configured to have no fibers. In the absorbent laminate 10, the adhesive is applied to the sheet members 12 and 22 to form the adhesive layers 14 and 24, and the water-absorbent resins 13 and 23 are fixed to the sheet members 12 and 22 by the adhesive layers 14 and 24. Has been done.

The upper absorption layer 11 has sealing portions 17 and 18 to which the sheet members 12 are joined to each other, and non-sealing portions 19 to which the sheet members 12 are not joined to each other. As shown in FIG. 2, the upper absorption layer 11 has an end region 15 and a central region 16 located between them on both sides in the width direction x, and a sealing portion 17 is formed in the end region 15. A sealed portion 18 and a non-sealed portion 19 are formed in the central region 16.

The lower absorption layer 21 has a sealing portion 27 to which the sheet members 22 are bonded and a non-sealing portion 29 to which the sheet members 22 are not bonded to each other. As shown in FIG. 3, the lower absorption layer 21 has an end region 25 and a central region 26 located between them on both sides in the width direction x, and a sealing portion 27 is formed in the end region 25. , The unsealed portion 29 is formed in the central region 26, and the sealed portion is not formed.

The absorbent laminate of the present invention is configured as described above, and the amount of the water-absorbent resin in the unsealed portion of the central region of the upper absorbent layer is A (g / m ² ), and that of the lower absorbent layer. When the amount of water-absorbent resin in the non-sealed portion of the central region is B (g / m ² ) and the amount of water-absorbent resin in the sealed portion of the central region of the upper absorption layer is C (g / m ² ). , A>B> C. By arranging the absorbent resin in this way, urine and the like can be suitably absorbed in the upper absorption layer and the lower absorption layer. This will be described in detail below.

The amount C of the water-absorbent resin in the sealing portion of the central region of the upper absorption layer is smaller than the amount A of the water-absorbent resin in the non-sealing portion of the central region of the upper absorption layer, so that the urine received in the upper absorption layer. Etc. are likely to diffuse in the plane direction in the sealing portion, and are easily transferred to the lower absorption layer through the sealing portion. Urine or the like diffused in the plane direction in the sealing portion of the upper absorbing layer is suitably absorbed and fixed in the non-sealing portion of the upper absorbing layer in which a larger amount of water-absorbing resin is arranged.

On the other hand, the amount B of the water-absorbent resin in the unsealed portion in the central region of the lower absorption layer is smaller than the amount A of the water-absorbent resin in the unsealed portion in the central region of the upper absorption layer, and the amount B of the upper absorption layer. It is larger than the amount C of the water-absorbent resin in the sealing portion in the central region. By arranging the water-absorbent resin in the lower absorption layer in this way, the absorption capacity of the lower absorption layer can be increased, and even if the sealing portion is not formed in the central region of the lower absorption layer, the sealing portion is not formed. It becomes easy to secure the diffusivity of the lower absorption layer such as urine in the plane direction. Further, since the amount of the water-absorbent resin arranged in the non-sealing portion of the lower absorption layer does not become excessive (that is, the relationship with B <A is satisfied), gel is formed by the water absorption of the water-absorbent resin, and urine or the like is formed. The amount of the water-absorbent resin that does not contribute to the absorption of urine or the like can be reduced as much as possible even if the diffusion of the water-absorbent resin or the permeation into the water-absorbent resin is inhibited.

The amount A of the water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer is preferably 200 g / m ² or more, and more preferably 250 g / m ² or more from the viewpoint of increasing the absorption capacity of the upper absorption layer. , 300 g / m ² or more is more preferable. The upper limit of the amount A of the water-absorbent resin arranged in the unsealed portion in the central region of the upper absorption layer is not particularly limited, but is preferably 1000 g / m ² or less, more preferably 800 g / m ² or less, and 600 g / m, for example. ² or less is more preferable, and this makes it easier to preferably maintain the sealed portion even if the water-absorbent resin in the non-sealed portion of the upper absorbing layer absorbs water.

The amount B of the water-absorbent resin arranged in the unsealed portion in the central region of the lower absorption layer is preferably 70 g / m ² or more, preferably 100 g / m ² or more, from the viewpoint of increasing the absorption capacity of the lower absorption layer. More preferably, 150 g / m ² or more is further preferable. On the other hand, as the upper limit of the amount B of the water-absorbent resin arranged in the unsealed portion in the central region of the lower absorption layer, the diffusibility of urine or the like in the lower absorption layer is ensured and it is effective for absorption of urine or the like. From the viewpoint of increasing the proportion of the water-absorbent resin that contributes to the above, 400 g / m ² or less is preferable, 350 g / m ² or less is more preferable, and 300 g / m ² or less is further preferable.

Amount A (g / m ² ) of water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer and amount B of water-absorbent resin arranged in the unsealed portion of the central region of the lower absorption layer. The ratio A / B of (g / m ² ) is, for example, preferably 1.2 or more, more preferably 1.3 or more, further preferably 1.4 or more, preferably 4.0 or less, and preferably 3.0 or less. More preferably, 2.5 or less is further preferable.

The amount C of the water-absorbent resin arranged in the sealing portion of the central region of the upper absorbing layer is 50 g / m ² or less from the viewpoint of ensuring the diffusivity and permeability of urine and the like in the sealing portion of the upper absorbing layer. Preferably, 40 g / m ² or less is more preferable, and 35 g / m ² or less is further preferable. On the other hand, the lower limit of the amount C of the water-absorbent resin arranged in the sealing portion in the central region of the upper absorption layer is not particularly limited, but it is preferable that a small amount of the water-absorbent resin is arranged, thereby forming the upper absorption layer. The absorption capacity can be increased, and the diffusivity of the upper absorption layer in the plane direction can be enhanced. That is, if the water-absorbent resin is arranged in the sealing portion in the central region of the upper absorption layer, the water-absorbent resin absorbs water and gels, so that the permeability of urine or the like in the sealing portion is suppressed and the sealing portion is sealed. In the portion, the diffusivity of the upper absorption layer in the plane direction can be enhanced. In particular, in the absorbent laminate of the present invention, since the sealing portion is not formed in the central region of the lower absorbent layer, the diffusivity of the lower absorbent layer in the plane direction tends to be slightly reduced. It is preferable that the diffusivity in the plane direction of the body is formed so as to be ensured by the upper absorption layer as much as possible. As a result, it becomes possible to contribute more of the water-absorbent resin arranged in the upper absorption layer and the lower absorption layer to absorption. The lower limit of the amount C of the water-absorbent resin arranged in the sealing portion of the central region of the upper absorption layer is, for example, preferably 5 g / m ² or more, more preferably 10 g / m ² or more, still more preferably 15 g / m ² or more. ..

The amounts A, B, and C of the water-absorbent resin described above represent the amount of the water-absorbent resin per unit area in the sealed or unsealed portion of the upper absorption layer or the lower absorption layer. The amount A (g / m ² ) of the water-absorbent resin in the non-sealing portion of the central region of the upper absorption layer is the amount of the water-absorbent resin arranged in all the non-sealing portions of the central region of the upper absorption layer. It is obtained by dividing by the area of the unsealed portion in the central region of the upper absorption layer. The amount B (g / m ² ) of the water-absorbent resin in the unsealed portion of the central region of the lower absorption layer is the amount of the water-absorbent resin arranged in the unsealed portion of the central region of the lower absorption layer. It is obtained by dividing by the area of the unsealed portion in the central region of the lower absorption layer. The amount C (g / m ² ) of the water-absorbent resin in the sealing portion of the central region of the upper absorption layer is the amount of the water-absorbent resin arranged in all the sealing portions of the central region of the upper absorption layer. It is obtained by dividing by the area of the sealing portion in the central region of the layer.

It is preferable that urine and the like are absorbed and fixed in the upper absorption layer as soon as possible. As a result, in the absorbent article provided with the absorbent laminate, it is possible to suppress the liquid return of urine or the like to the top sheet side. From this point of view, it is preferable to use a water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer having a high water absorption rate, and specifically, the unsealed portion of the central region of the upper absorption layer. The water-absorbent resin arranged on the stop portion preferably has a water absorption rate of 20 seconds or less by the vortex method, more preferably 18 seconds or less, and further preferably 16 seconds or less. The lower limit of the water absorption rate is not particularly limited, but is preferably 5 seconds or longer, and more preferably 8 seconds or longer.

On the other hand, in the lower absorption layer, it is preferable to use a water-absorbent resin having a slower absorption rate than the upper absorption layer, whereby the diffusibility in the lower absorption layer can be enhanced. From this point of view, the water-absorbent resin arranged in the unsealed portion of the central region of the lower absorption layer is a vortex method rather than the water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer. It is preferable that the water absorption rate is slow. For example, the water-absorbent resin arranged in the unsealed portion in the central region of the lower absorption layer has a higher water absorption rate by the vortex method than the water-absorbent resin arranged in the unsealed portion in the central region of the upper absorption layer. It is preferably 5 seconds or more slower, more preferably 10 seconds or more slower, and even more preferably 20 seconds or more slower.

The water absorption rate of the water-absorbent resin by the vortex method is measured according to JIS K 7224 (1996). Specifically, the water absorption rate is obtained as follows. A glass beaker with a capacity of 100 mL is coated with 50 mL of physiological saline (0.9 mass% sodium chloride water) and a magnetic stirrer chip (center diameter 8 mm, both ends diameter 7 mm, length 30 mm, and the surface is coated with fluororesin. Put the thing) and put the beaker on the magnetic stirrer (HPS-100 manufactured by AS ONE Co., Ltd.). Adjust the rotation speed of the magnetic stirrer to 600 ± 60 rpm and stir the saline solution. 2.0 g of the water-absorbent resin was poured into the liquid at the center of the vortex of the saline solution being stirred, and when the water-absorbent resin was completely charged into the beaker, the counting was started and the stirrer chip was covered with the test liquid. Stop the counting at the time when the stirrer disappears (when the vortex disappears and the liquid surface becomes flat), and record the time (seconds) as the water absorption rate. The measurement is performed 5 times (n = 5), the values at each of the upper and lower points are deleted, and the average value of the remaining 3 points is used as the measured value. The measurement is performed at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%, and the water-absorbent resin is held in the same environment for 24 hours or more before the measurement.

From the viewpoint of promptly absorbing urine or the like in the absorbent laminate, it is also preferable that the upper absorbent layer is configured as follows. That is, it is preferable that the basis weight of the sheet member arranged on the skin surface side of the upper absorption layer is larger than the basis weight of the sheet member arranged on the non-skin surface side. By forming the basis weight of the sheet member arranged on the skin surface side of the upper absorption layer to be larger, it becomes possible to make the capillary effect of the sheet member more effective. Therefore, the sheet member on the skin surface side of the upper absorption layer can quickly draw urine or the like received by the absorbent laminate into the inside of the upper absorption layer, and as a result, rapid absorption of urine or the like is realized. can do. Further, by forming the upper absorbent layer in this way, when the absorbent laminate is touched from the skin surface side or when the absorbent article provided with the absorbent laminate is touched from the top sheet side, the upper side is formed. It is possible to reduce the feeling of roughness due to the water-absorbent resin of the absorbent layer.

The lower absorption layer may also be formed so that the basis weight of the sheet member arranged on the skin surface side is larger than the basis weight of the sheet member arranged on the non-skin surface side. This facilitates the rapid migration of urine or the like that has permeated the upper absorption layer to the lower absorption layer.

In the upper absorption layer and the lower absorption layer, the sheet member is preferably made of a non-woven fabric from the viewpoint of promptly drawing urine or the like into the sheet member. In particular, it is preferable to use an air-through non-woven fabric or a spunlace non-woven fabric as a sheet member as a non-woven fabric which is relatively bulky and has an excellent pulling force for urine or the like.

It is also preferable that the sheet member made of the non-woven fabric contains heat-sealing fibers. Examples of the heat-sealing fiber include polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as PET, and polyamide fibers such as nylon. If the sheet members are configured in this way, it becomes easy to weld the sheet members together at the sealing portion, and even if the upper absorption layer or the lower absorption layer absorbs water, the sheet members can be joined to each other. It will be easier to maintain. In particular, the upper absorption layer is made of a non-woven fabric in which the skin surface side and non-skin surface side sheet members contain heat-sealing fibers from the viewpoint of ensuring the diffusibility of urine and the like in the sealing portion in the central region. Is preferable.

The nonwoven fabric containing the heat-sealing fibers is preferably composed of fibers containing at least a polyethylene resin. In the nonwoven fabric configured in this way, the sheet members can be firmly bonded to each other by forming the sealing portion by heat sealing or ultrasonic welding. Further, if the non-woven fabric composed of fibers containing polyethylene resin is an air-through non-woven fabric, the fibers can be firmly adhered to each other, and even if the upper absorption layer or the lower absorption layer absorbs water and swells, for example. The seat member is less likely to break.

The fiber containing the polyethylene resin may have only polyethylene as the resin or may have another resin, but it is preferable to have a polyethylene resin and a resin having a higher melting point than the polyethylene resin. .. As the fiber composed of such a plurality of resins, it is preferable to use a composite fiber having a core-sheath structure or a side-by-side structure, and the polyethylene resin is one component of the composite fiber (for example, a sheath component having a core-sheath structure or a side-by-side structure). It is preferable to form one component of the structure).

Therefore, the sheet member of the upper absorption layer and / or the lower absorption layer is preferably made of an air-through nonwoven fabric composed of fibers containing polyethylene resin, and in particular, the upper absorption layer absorbs water and swells in the central region. From the viewpoint of maintaining the sealing portion, it is preferably made of an air-through nonwoven fabric composed of fibers containing polyethylene resin.

The upper absorption layer may have only one layer structure having a water-absorbent resin between the sheet members and not having pulp fibers, or may have a plurality of layer structures. In the latter case, it is preferable that a plurality of sealing portions in the central region of the upper absorption layer are laminated so as to overlap each other.

The lower absorption layer may also have only one layer structure having a water-absorbent resin between the sheet members and not having pulp fibers, or may have a plurality of layers. Since the lower absorption layer does not have a sealing portion in the central region and is inferior in the vertical permeability of urine or the like, the lower absorption layer has a water-absorbent resin between the sheet members. It is preferable to have only one layer structure configured so as not to have pulp fibers.

Next, the absorbent article of the present invention will be described. The absorbent article of the present invention is characterized in that the absorbent laminate of the present invention is provided, and the absorbent laminate of the present invention is arranged between the top sheet and the back sheet. Examples of the absorbent article include a urine pad (including an incontinence pad), a disposable diaper, a sanitary napkin, and the like. The absorbent article of the present invention has excellent absorption performance by providing the absorbent laminate described above.

The shape of the absorbent article is not particularly limited. When the absorbent article is, for example, a urine pad or a menstrual napkin, the shape of the absorbent article may be rectangular, hourglass-shaped, gourd-shaped, battledore-shaped or the like.

When the absorbent article is a disposable diaper, the disposable diaper may be a tape-type disposable diaper provided with fastening members on both the left and right sides and formed into a pants shape by the fastening members, and may be a waist opening. It may be a pants-type disposable diaper in which and a pair of leg openings are formed. In the pants-type disposable diaper, the absorbent body in which the absorbent laminate of the present invention is arranged between the top sheet and the back sheet is attached to the skin surface side of the exterior member formed in the shape of pants. You may.

The top sheet is provided on the skin surface side of the absorbent laminate and is liquid permeable. The top sheet is provided so as to face the wearer's skin when wearing the absorbent article. Examples of the top sheet include non-woven fabrics formed from hydrophilic fibers such as cellulose, rayon and cotton; and hydrophobicity such as polyolefins (eg polypropylene, polyethylene), polyesters (eg PET) and polyamides (eg nylon). A non-woven fabric formed from fibers, in which the surface of the hydrophobic fibers is hydrophilized with a surfactant, or the like can be used. Further, as the top sheet, a woven cloth, a knitted cloth, or a plastic film having holes may be used.

The back sheet is provided on the non-skin surface side of the absorbent laminate and is impermeable to liquid. The backseat is provided so that when the absorbent article is worn, it faces the opposite side of the wearer, that is, the outside. As the back sheet, a non-woven fabric formed of hydrophobic fibers such as polyolefin (for example, polypropylene, polyethylene), polyester (for example, PET), polyamide (for example, nylon), a plastic film, or the like can be used. Further, a laminate of a non-woven fabric and a plastic film may be used.

When the top sheet or back sheet is made of a non-woven fabric, it is preferable to use a spunbonded non-woven fabric, an air-through non-woven fabric, a point-bonded non-woven fabric, a melt blow non-woven fabric, an air-laid non-woven fabric, an SMS non-woven fabric, or the like.

It is preferable that the absorbent article is provided with rising flaps on both sides in the width direction on the skin surface side. By providing the rising flap, lateral leakage of body fluid such as urine is prevented. For the rising flap, for example, side sheets extending in the longitudinal direction are joined to both sides in the width direction of the top sheet, and elastic members are provided inward in the width direction of the side sheet (near the upper end when the rising flap stands up). It is formed by. By providing the side sheet and the elastic member in this way, the inner side of the side sheet in the width direction rises toward the wearer's skin due to the contraction force of the elastic member, and a rising flap is formed. The rising flap or side sheet is preferably made of a liquid-impermeable plastic film, a liquid-impermeable non-woven fabric, or the like.

The absorbent article of the present invention will be described with reference to FIGS. 4 and 5 by taking a urine pad as an example. The absorbent article of the present invention is not limited to the embodiments shown in the drawings. 4 and 5 show absorbent articles with the absorbent laminates shown in FIGS. 1 to 3. FIG. 4 shows a plan view of the urine pad as an absorbent article as viewed from the top sheet side, and FIG. 5 shows a VV cross-sectional view of the absorbent article shown in FIG.

The absorbent article 1 has a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and an absorbent laminate 10 provided between them. The top sheet 2 is arranged on the skin surface side of the absorbent laminate 10 and permeates body fluids such as urine. The body fluid that has permeated the top sheet 2 is housed in the absorbent laminate 10. The back sheet 3 is arranged on the non-skin surface side of the absorbent laminate 10 to prevent the body fluid from leaking to the outside.

The absorbent laminate 10 has an upper absorbing layer 11 and a lower absorbing layer 21 from the top sheet 2 side. The detailed configuration of the absorbent laminate 10 is as described above. For example, referring to FIG. 1, the upper absorption layer 11 has sealing portions 17 and 18 to which the sheet members 12 are joined to each other, and non-sealing portions 19 to which the sheet members 12 are not joined to each other, and has x in the width direction. Sealed portions 17 are formed in the end regions on both sides, and a sealed portion 18 and a non-sealed portion 19 are formed in a central region between them. The lower absorption layer 21 has a sealing portion 27 to which the sheet members 22 are joined to each other and a non-sealing portion 29 to which the sheet members 22 are not joined to each other, and is sealed in the end regions on both sides in the width direction x. The portions 27 are formed, the unsealed portion 29 is formed in the central region between them, and the sealed portion is not formed. Then, the amount of the water-absorbent resin in the unsealed portion 19 in the central region of the upper absorption layer 11 is A (g / m ² ), and the amount of the water-absorbent resin in the unsealed portion 29 in the central region of the lower absorption layer 21. Is B (g / m ² ), and the amount of the water-absorbent resin in the sealing portion 18 in the central region of the upper absorption layer 11 is C (g / m ² ), so that the relationship of A>B> C is satisfied. It is configured in. By providing the absorbent laminate 10 configured in this way, the absorbent article 1 exhibits excellent absorption performance of urine and the like.

It is preferable that the upper mount 4 is provided between the top sheet 2 and the absorbent laminate 10. Further, it is preferable that the lower mount 5 is provided between the back sheet 3 and the absorbent laminate 10. The upper mount 4 and the lower mount 5 are provided to improve the diffusivity of body fluids such as urine and to prevent the absorbent article 1 from losing its shape. The upper mount 4 is preferably liquid permeable, and the lower mount 5 may be liquid permeable or liquid impermeable. As the upper mount 4 and the lower mount 5, tissue paper, crepe paper, or the like can also be used.

It is preferable that the absorbent article 1 is provided with side sheets 6 extending in the longitudinal direction y on both sides of the top sheet 2 in the width direction x. The side seats 6 are joined to both sides of the top seat 2 in the width direction x. In FIGS. 4 and 5, three elastic members 7 for standing upright are provided on the side seats 6 inward in the width direction x, respectively. When the absorbent article 1 is used, the inner side of the side sheet 6 rises toward the wearer's skin due to the contraction force of the elastic member 7 for standing up, thereby forming a rising flap and preventing lateral leakage of excrement such as urine. Will be done.

1: Absorbent article 2: Top sheet 3: Back sheet 10: Absorbent laminate 11: Upper absorption layer 21: Lower absorption layer 12, 22: Sheet member 13, 23: Water-absorbent resin 14, 24: Adhesive layer 15,25: End area 16,26: Central area 17,18,27: Sealed part 19,29: Unsealed part

Claims (7)

An absorbent laminate used to absorb body fluids and having a longitudinal direction and a width direction.
The absorbent laminate has an upper absorption layer arranged on the skin surface side and a lower absorption layer arranged on the non-skin surface side.
The upper absorption layer and the lower absorption layer are each configured to have a water-absorbent resin between the sheet members and not to have pulp fibers, and the sealing portion to which the sheet members are bonded and the sheet members are bonded to each other. Has an unsealed part that is not
The upper absorption layer and the lower absorption layer each have an end region and a central region located between them on both sides in the width direction.
In the upper absorption layer, the sealing portion is formed in the end region, and the sealing portion and the non-sealing portion are formed in the central region.
In the lower absorption layer, the sealing portion is formed in the end region, the non-sealing portion is formed in the central region, and the sealing portion is not formed.
The amount of water-absorbent resin in the unsealed portion of the central region of the upper absorption layer is A (g / m ² ), and the amount of water-absorbent resin in the unsealed portion of the central region of the lower absorption layer is B (g / m 2). / M ² ), when the amount of the water-absorbent resin in the sealing portion of the central region of the upper absorption layer is C (g / m ² ), the absorbability is characterized by satisfying the relationship of A>B> C. Laminated body. The amount A of the water-absorbent resin in the unsealed portion of the central region of the upper absorption layer is 200 g / m ² or more and 1000 g / m ² or less .
The amount B of the water-absorbent resin in the unsealed portion of the central region of the lower absorption layer is 70 g / m ² or more and 400 g / m ² or less .
The absorbent laminate according to claim 1, wherein the amount C of the water-absorbent resin in the sealing portion of the central region of the upper absorbent layer is 5 g / m ² or more and 50 g / m ² or less. The absorbent laminate according to claim 1 or 2 , wherein the sheet members are welded to each other in the sealing portion. The absorbent laminate according to any one of claims 1 to 3 , wherein the sheet member of the upper absorbent layer is made of an air-through nonwoven fabric composed of fibers containing polyethylene resin. The absorption layer according to any one of claims 1 to 4 , wherein the upper absorption layer has a basis weight of the sheet member arranged on the skin surface side larger than the basis weight of the sheet member arranged on the non-skin surface side. Sexual laminate. The absorbent laminate according to any one of claims 1 to 5 , wherein the water absorption rate of the water-absorbent resin arranged in the unsealed portion of the central region of the upper absorption layer is 20 seconds or less by the vortex method. The absorbent laminate according to any one of claims 1 to 6 and the absorbent laminate.
A liquid-permeable top sheet provided on the skin surface side of the absorbent laminate and
An absorbent article characterized by having a liquid-impermeable back sheet provided on the non-skin surface side of the absorbent laminate.

Images