JP5580169B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as sanitary napkins, panty liners, and incontinence pads, and more specifically, absorptive for women that can easily wash and remove redness such as menstrual blood that has been absorbed by water washing after use. It relates to goods.

  For absorbent articles such as sanitary napkins, there are various needs for performance depending on the region. For example, some people in Indonesia, Malaysia, etc. have a habit of washing used sanitary napkins with water and washing off absorbed menstrual blood. This washing is performed, for example, by applying pressure inward in the width direction to the sanitary napkin by squeezing and washing the sanitary napkin with the other hand while applying water with one hand. Conventionally, as a sanitary napkin suitable for such washing, a cloth napkin or a water absorbent material mainly composed of pulp fibers and containing no water absorbent polymer has been used. However, a sanitary napkin that does not contain such a water-absorbing polymer needs to use a large amount of pulp fiber in order to suppress liquid return due to low absorption and retention of menstrual blood. For this reason, sanitary napkins become thick due to the bulkiness of the pulp fibers, and are particularly bulky when folded and packaged, are inconvenient to carry, and have a poor fit.

  In order to solve such a problem, Patent Document 1 discloses an improved pulp fiber with a water-absorbing polymer that is easy to wash. This water-absorbing polymer has a carboxy group and / or a carboxylate group and has physical properties such as a predetermined degree of neutralization, and has weakened adhesion to redness components such as hemoglobin in menstrual blood. In addition, redness such as menstrual blood can be easily removed by washing with water after use.

JP 2010-17536 A

  When washing the sanitary napkin, if it is washed with one hand while applying water, if too much force is applied, the peripheral edge or surface material of the sanitary napkin will be broken and the absorbent material will break out (internal absorption) The fiber material constituting the body may leak out). In particular, depending on the amount of washing water and the manner of washing, the absorbent body material may be offset from the seal part at the outer peripheral edge of the napkin and accumulate. If discharge of washing water is hindered by the accumulation of this material, the water pressure inside the sanitary napkin rises and the seal portion may be broken. As a result, the absorbent material or the like breaks out and soils the washing area. Further, menstrual blood only diffuses in the plane direction of the napkin, so that menstrual blood or the like cannot be removed by washing, and the inside and the surface side of the napkin become dirty and are not sufficiently washed.

  In view of the above-mentioned specific problems when washing sanitary napkins after use, the present invention makes it easier to discharge washing water and improves washing efficiency, thereby making dirt such as menstrual blood on absorbent articles more than necessary. It is an object of the present invention to provide an absorbent article that is not diffused and that can effectively prevent breakage of the absorbent body material.

  The present invention is a vertically long absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets, In the peripheral region of the absorbent article, the surface sheet and the back sheet have a joint portion joined without interposing an absorbent body, and at least the joint portion in the peripheral region of the longitudinal front and rear ends of the absorbent article, The above-described problems are solved by an absorbent article having an uneven shape in plan view.

  The absorbent article of the present invention does not diffuse dirt such as menstrual blood of the absorbent article more than necessary by facilitating the discharge of washing water and improving the washing efficiency, and the breakthrough of the absorbent material is effective Excellent operational effects can be achieved.

It is the partial notch perspective view which showed the sanitary napkin as preferable one Embodiment (Embodiment 1) of the absorbent article in this invention from the skin contact surface direction. It is the expanded sectional view which showed typically the polymer reservoir in the predetermined cross section at the time of wash | cleaning the sanitary napkin of Embodiment 1 shown in FIG. 1 with water etc., AA sectional view is (i), B The cross section along line -B is (ii). It is the top view which showed typically a part of junction part as another embodiment (Embodiment 2) in this invention. It is the top view which showed typically a part of junction part as another embodiment (Embodiment 3) in this invention. It is the top view which showed typically a part of junction part as another embodiment (Embodiment 4) in this invention. It is the top view which showed typically a part of junction part as another embodiment (Embodiment 5) in this invention. It is the top view which showed typically a part of junction part as another embodiment (Embodiment 6) in this invention. It is the top view which showed typically a part of joining part as another embodiment (Embodiment 7) in this invention.

  FIG. 1 is a partially cutaway perspective view showing a sanitary napkin 10 as a preferred embodiment (Embodiment 1) of an absorbent article according to the present invention from the skin contact surface direction. In order to avoid complication of the drawing, the joint portion of the cut out portion of the top sheet 1 and the back sheet 2 is not shown. In the present invention, unless otherwise specified, the surface in contact with the human body is referred to as the skin side surface or skin contact surface or surface, and the opposite surface is referred to as the non-skin surface or non-skin contact surface or back surface. Of these two surfaces, the side close to the skin side or the extending direction is called the skin side, the skin contact surface side or the surface side, and the side close to the non-skin surface or the extending direction is the non-skin side, non-skin It is called the contact side or the back side. The direction positioned on the front side of the human body when worn is referred to as the front, and its end is referred to as the front end, and the direction positioned on the rear is referred to as the rear, and the end is referred to as the rear end. The normal direction of the front or back surface of the absorbent article is called the thickness direction, and the amount is called thickness. Furthermore, in the plan view of the absorbent article, a direction from the abdominal side to the back side through the crotch is referred to as a vertical direction, and a direction orthogonal to the vertical direction is referred to as a width direction. The vertical direction typically coincides with the front-rear direction of the human body when worn.

  First, the overall configuration of the sanitary napkin 10 according to the first embodiment will be described. The top sheet 1 disposed on the skin contact surface side, the back sheet 2 disposed on the non-skin contact surface side, and both sheets are interposed. An absorber 3 is provided. Further, the side sheets 4 and 4 cover the left and right side edges in the longitudinal direction (Y direction) of the absorbent body 3 via the top sheet 1 and come into contact with the back sheet 2 outside the width direction (X direction) of the absorbent body 3. Are joined. At the portion where the back sheet 2 and the side sheet 4 are in contact, the end in the width direction of the top sheet 1 is sandwiched. A pocket (not shown) is formed between the free end 41 of the side sheet 4 and the top sheet 1 and has an effect of preventing lateral leakage of liquid or the like. Wings 42 formed by extending the side sheets 4 and the back sheet 2 are disposed on the left and right sides of the sanitary napkin 10 in the width direction. The top sheet 1, the back sheet 2, and the side sheet 4 laminated in this way form the outer shape of the napkin outside the absorber 3. When the sanitary napkin 10 is used, the wing portion 42 is wound around the crotch non-skin contact surface side of the shorts to fix the sanitary napkin 10 to the shorts.

  On the skin contact surface side of the sanitary napkin 10, a leak-proof groove 7 squeezed from the skin contact surface side of the top sheet 1 to the absorber 3 is provided. The leak-proof grooves 7 are disposed on the left and right sides in the width direction around the excretion portion in the longitudinal center portion of the absorber 3, and the two leak-proof grooves 7 gradually approach the front and rear ends of the absorber 3. The absorber 3 curves toward the center, and the front end and the rear end coincide with each other. The leak-proof groove 7 has an endless annular continuous shape in plan view. The shape of the leak-proof groove 7 in the present embodiment is such that the front-end and the rear-end coincide with each other in an endless annular shape, but the present invention is not limited to this. For example, the front-end and the rear-end intersect each other. It may be suitable, and it is preferable that it is determined appropriately according to the application. The excretory part is a part that directly receives excretion of menstrual blood or vaginal discharge and its vicinity.

  Details regarding the materials and dimensions of the top sheet 1, the back sheet 2, the side sheet 4, and the absorber 3 will be described later. In the present embodiment, the top sheet 1 uses a hydrophilic air-through nonwoven fabric from the viewpoint of promptly absorbing the excreted liquid and transmitting it to the absorber and from the viewpoint of good touch. Further, as the back sheet 2, a breathable moisture permeable film is used as a single layer. As the absorbent body 3, an absorbent core made of a fiber material such as pulp fiber and an absorbent polymer is coated with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. Moreover, the adhesive (not shown) for fixing the sanitary napkin 10 to clothing is applied to the non-skin contact surface side of the back sheet 2. The sanitary napkin 10 is adhesively fixed to the user's clothes by the adhesive. The sanitary napkin 10 of the present embodiment is arranged with its top sheet side facing the wearer's skin contact surface side and its longitudinal direction extending from the lower abdomen to the buttocks, in other words, its width direction is set to the left and right feet. Arrange for the direction of the line to connect.

In the present embodiment, in the peripheral region 6 that forms the outer periphery of the napkin 10, there is a joint portion 5 in which the sheets are joined by heat sealing or the like without the absorber 3 so that the liquid once absorbed does not leak to the outside. It is arranged. The joining part 5 formed in the peripheral region 6 is an end joining part 51 outside the absorber end part formed by joining the back sheet 2 and the top sheet 1, and an end side obtained by joining the side sheet 4 to the both sheets. It consists of the junction part 52 and the side junction part 53 outside the absorber side part formed by joining the side sheet 4 and the back sheet 2. Each joint portion is formed by pressing and fixing laminated sheets by heat sealing.
In the present invention, the peripheral region 6 refers to a region where the sheet members outside the absorbent body 3 where the absorbent body 3 does not exist are laminated, and the inner peripheral edge 61 of the absorbent article (the napkin 10 in this embodiment) This refers to the region up to the end 31 of the absorber toward the direction. In the portion where the end joint portion 51 is present, the top sheet 1 and the back sheet 2 are laminated to form a peripheral region 6. The width of the peripheral region 6 cannot be determined uniquely because it varies depending on the size or purpose of use of the article. However, in the case of the napkin 10 of the present embodiment, normally, from the absorber end 31 to the outer peripheral end 61 of the napkin. 2 mm to 20 mm. Since the present invention relates to the front and rear ends of the napkin, the presence or absence of wings on the side of the napkin is not affected.

In the present embodiment, as described above, the end joint portion 51 is a joint portion in which the topsheet 1 and the backsheet 2 are joined to the outside of the end portion 31 of the absorber without interposing the absorber. The planar view shape is a corrugated joining form in which the uneven shape is continuous and separated from the end 31 of the absorber 3 by at least two different distances. The corrugated shape is a shape in which an inward protruding portion g ₁ that protrudes toward the absorber 3 and an outward protruding portion g ₂ that protrudes outward from the absorber 3 formed adjacent thereto are repeatedly connected. , Sinusoidal shape. In such a wave-shaped end joint portion 51, it is possible to firmly prevent liquid leakage during use, and to impart moderate flexibility to a portion that tends to be generally high in rigidity. Therefore, high flexibility is exhibited in this portion, and good fit and soft touch can be expressed.

Normally, in washing a napkin, water is applied with one hand while the sanitary napkin is swabbed or squeezed with the other hand, thus applying pressure inward in the width direction to the sanitary napkin. . At that time, pressure due to scouring works to push the washing water inside the absorbent body to the outside, and the absorbent material is part of the absorbent material that absorbs a large amount of fiber material and water that make up the absorbent body. May separate from the inside. The polymer or the like is pushed by pressure such as scouring, and moves more in the longitudinal direction of the sanitary napkin, so that the polymer stays and accumulates at the joint portion on the periphery of the napkin outside the end of the absorbent body.
In many cases, the sanitary napkin is washed to remove dirt such as menstrual blood. In order to effectively clean the inside and the surface of the absorbent article without diffusing the dirt, (1) the internal passage of the poured cleaning water into the absorbent body, (2) the discharge of the contaminated cleaning water to the outside It is important that the two processes are efficiently performed, that is, “the metabolism of washing water”. However, in the conventional napkin, the polymer pool hinders water migration at the front and rear ends of the napkin, and causes a significant decrease in the metabolism of the washing water.

In the napkin 10 of the present embodiment, on the other hand, outside the absorbent body 3 is formed and its adjacent inwardly protruding g ₁ is a projection of the end joints 51 as described above for the absorbent body 3 a wave shape of sinusoidal and outward projection g ₂ are repeatedly formed a projection directed. The end joint 51 has a longer line length in a plan view than a conventional joint having a constant distance from the absorbent body along the outer periphery of the napkin. As a result, the end joint 51 has a larger contact area with the washing water or polymer that flows out during cleaning, and the hydraulic pressure received by the end joint 51 during cleaning is dispersed. Thus, by lowering the hydraulic pressure applied to the unit area of the end joint portion 51 of the present embodiment, the tearing of the topsheet 1 due to the hydraulic pressure during cleaning is suppressed, and the outflow of the polymer, fiber material, etc. inside the absorbent body is suppressed. Can be effectively prevented. As a result, the end joint portion 51 of the napkin 10 can flow out without stagnation of the wash water and prevent a decrease in the metabolism of the wash water.
This operation will be described with reference to FIG. FIG. 2 is an enlarged cross-sectional view schematically showing a state of a polymer pool in a predetermined cross section when the sanitary napkin shown in FIG. 1 is washed with water or the like, and the cross section along line AA is (i). The cross section along line BB is (ii). In addition, the polymer reservoir W indicated by a one-dot chain line in the drawing is schematically shown and does not necessarily have the same shape as illustrated in the implementation of the present invention.

To wash with water sanitary napkin 10, the cleaning water T ₁ than the skin contact surface side of the topsheet 1 is hydrophilic poured into the sanitary napkin, rubbing stains menstrual blood or the like to the wash water by washing or the like and it moves the redness and contaminated wash water T _2, it is necessary to discharge the contaminated wash water T ₂ to the outside of the sanitary napkin. When pressure inward in the width direction is applied to clean the sanitary napkin, moisture is first adsorbed by the polymer, separated from the absorber 3 and pushed out from the inside of the absorber 3 to transfer and joined. It will contact the part 5. In the end joint 51 of the present embodiment, by repeatedly (see FIG. 1) between the outer protrusion g ₂ and the inner projections g ₁ which inward which outwardly of the absorbent body 3, the end junction A large number of pocket portions P are formed on the absorber 51 side. When the polymer or the like is transferred to such a shape by washing or the like as described above, the polymer or the like comes into contact with the inward projection g ₁ (see FIG. 1 circle inner view, FIG. 2 (i)) and its hydraulic pressure. And is distributed and accumulated in the pocket P formed by the inward projection g ₁ and the outward projection g ₂ (see the inner circle in FIG. 1, see FIG. 2 (ii)) (FIG. 2 (ii) reference). Furthermore, in the end joints 51, so outflows of the polymers spread longitudinally distributed inside the plurality of outwardly protruding g _2, polymers as in the prior art is avoided that the piling up high in the thickness direction Therefore, the increase in the water pressure of the washing water is reduced. This also makes it difficult for the end joint portion 51 and the surface sheet 1 at that portion to be torn.

Next, the water poured exceeding the water absorption capacity of the polymer becomes contaminated washing water T ₂ by scouring or the like, passes through the absorbent body 3 and is pushed out from the inside of the absorbent body 3 to migrate, and ends up like the polymer. It contacts the part 51. However, since it is difficult polymeric reservoir W prevents the migration of the liquid is formed in the inwardly projecting portion g ₁ portion of the end joints 51 as described above, the contaminated wash water T ₂ in a wide range of the surface sheet 1 of this portion It can be an outflow path (see FIG. 2 (i)). The polymer reservoir W is formed in the pocket P which extends in the longitudinal direction by being provided with outwardly projecting portion g ₂ at a position away from the absorbent body 3 (see FIG. 2 (ii)). Thus the accumulation in the longitudinal direction has priority, is accumulated suppressed in the thickness direction, also it can be a channel for contaminated wash water T ₂ in the topsheet portion of the upper surface of the W reservoir polymer (FIG. 2 (ii)). Therefore, the sanitary napkin 10 of the present embodiment, reservoir polymer prevents the metabolism of washing water can be performed preferentially drainage contaminated wash water T ₂ in the portion of the above does not occur. Further, the above-described dispersion structure of the hydraulic pressure received by the joining portion from the polymer W reservoir is not easily broken in the vicinity of the end joining portion 51, and the sanitary napkin as a whole has an effect of efficiently performing the cleaning water metabolism.

The size and shape of the end joint portion 51 according to the first embodiment are not particularly limited, but considering the cleaning of the sanitary napkin, the pitch h of the inward projection g ₁ is slightly different depending on the use of the absorbent article to be used. ₁ (see FIG. 1) is preferably 2 to 40 mm, and more preferably 5 to 20 mm. The radius of curvature _{r 1} of the tip arc is preferably 0.5 to 50 mm, 2 to 30 mm is more preferable. Pitch _{h 2} of the outer projection _{g 2} is preferably 2 to 40 mm, 5 to 20 mm is more preferable. The curvature radius r2 of the tip arc is preferably 0.5 to 50 mm, and more preferably ₂ to 30 mm. Further, the height difference h ₃ between the inner protrusion g ₁ and the outer protrusion g ₂ is preferably ₃ to 40 mm, more preferably 5 to 20 mm, and the inner protrusion g ₁ from the end 31 of the absorber. The distance difference h4 is preferably ₂ to 40 mm, more preferably 5 to 20 mm.

The joint portion in the present invention has a structure and physical properties such that heat sealing, ultrasonic sealing, biting, hot melt bonding, etc., integrate at least two sheet materials and do not easily dissociate.
The heat seal in the present invention refers to a state in which heat is applied in a state where sheet materials including a thermoplastic resin are overlapped and the sheets are integrated by heat melting. As a heat sealing processing method, the plurality of sheets are introduced between a first roll having a concavo-convex shape on the peripheral surface and a second roll having a flat shape to perform heating and pressure bonding. A typical method is to perform heat melting. Heat sealing is preferable from the viewpoint of bonding stability after bonding.
A method of melting and solidifying the resin using ultrasonic waves instead of heat may be used. In this case, an ultrasonic seal can be provided by providing an ultrasonic oscillation device on either the first roll having a concavo-convex shape on the peripheral surface or the second roll having a flat shape. . Since the ultrasonic sealing process can be melted and solidified even if it is not a thermoplastic resin, it is preferable in that the number of types of resins that can be used increases.
The plurality of sheets are interposed between a first roll having a concavo-convex shape on the peripheral surface and a second roll having a concavo-convex shape meshing with the concavo-convex shape of the first roll on the peripheral surface. A method of introducing, biting, and adhering may be used.
Furthermore, the process of introducing between rolls can be omitted by adopting the application pattern of the hot melt adhesive in the form of the present invention.
Of these methods, the bonding portion can be formed by using any one of the methods, but a stronger bonding portion can be formed by using two or more methods. In addition, when providing a strong peelable part and a weak part in the joint, the strong part is joined by combining a plurality of methods, and the weak part is easily joined by using any one method. It is also possible to provide a portion.

In the present invention, the shape of the end joint portion 51 is not particularly limited, and any shape can be adopted. For example, it is preferable not to be corrugated as shown, but to be appropriately determined according to the application and use site such as zigzag or semi-continuous circle.
In the present invention, the uneven shape in plan view of the joint portion 51 is a shape having at least one kind of a long portion and a short portion from the end 31 of the absorber 3 to the joint portion. Moreover, that uneven | corrugated shape is continuing means that it is substantially continuous, and the gap | interval of the grade which cannot pass the structure of an absorber at the time of washing | cleaning may be included. In other words, the joining portion 51 of the present invention is on a straight line arbitrarily extending in the direction from the end of the absorber 3 to the outer peripheral end 61, so that there is no portion without the joining portion and the washing water does not flow out to the outside as it is. A structure that can be dammed. Therefore, the present invention is not limited to the joint portion 51 formed by a single line, and a plurality of joints may be formed so as to partially overlap or intersect on the straight line. For example, the joining line in which g ₁ , g ₂ , and g ₁ are connected side by side is continuously arranged, and the joining line itself may be an intermittent line, or g ₁ , g _A plurality of joint lines may be arranged so that the unit joint lines connecting ₂ and g ₁ intersect intermittently or intersect. Further, the arrangement range may be arranged so as to cover the entire periphery of the napkin 10 from the end joint portion 51 to the end side joint portion 52 and further to the side joint portion 53, or the end joint portion 51. It may be arbitrarily arranged arbitrarily at a place necessary for the joint 51.
Below, the said change aspect is demonstrated.

  FIG. 3 is a plan view schematically showing a part of a joining portion as another embodiment (embodiment 2) in the present invention. Except for having a region 54 (region shown by a halftone dot in the figure) having a weaker bonding force than the end joint 51 in the peripheral portion of the end joint 51 of the first embodiment, the same as the embodiment shown in the first embodiment. Yes, the lower side in the figure is the absorber side. In the present embodiment, in the weakly bonded region 54, the inner bonded portion of the weakly bonded region 54 is peeled off and the end bonded portion 51 appears while having a strong leak-proof property when mounted and used. When this end joint 51 appears at the time of cleaning, the above-described efficient cleaning water metabolism and prevention of outflow of polymer, fiber material and the like inside the absorbent body due to tearing of the surface sheet 1 can be realized. In the second embodiment, “weak bonding strength” means that it is not broken by the diffusion of menstrual blood or the like during wearing and the body pressure of the wearer, and is easily broken by a large amount of washing water at the time of washing. It is weakness. The bonding strength is such that the napkin is grasped by hand and the cleaning water is peeled off and the peeling strength (according to JIS Z 0238 (heat seal strength)) is about 1 to 100 g / 15 mm. In addition to the method of selecting a plurality of joining means as described above, the weakly joined region 54 is formed by providing a step on a roll for providing a heat seal to control the degree of pressure bonding during processing. A method is conceivable. Also, it is possible to use a method in which heat sealing is performed in two steps, the weakly bonded region and the strongly bonded region are bonded together in the first hot roll step, and only the strong bonded region is resealed in the next hot roll step. it can. The width (length in the longitudinal direction) of the weakly bonded region 54 is preferably 5 to 40 mm, and more preferably 10 to 30 mm. Moreover, it is preferable that the length (width direction length) of the joining area | region 6 exists in the whole product edge part. The strong joint portion has a stronger joint strength than the weak joint portion, and preferably has a peel strength of 5 g / 15 mm or more, and preferably 50 g / 15 mm or more than the weak joint portion.

  FIG. 4 is a plan view schematically showing a part of a joining portion as another embodiment (Embodiment 3) in the present invention. Except for the shape of the end joint portion 51 being different, the configuration is the same as that shown in the first embodiment, and the lower side in the figure is the absorber side. In the present embodiment, the shape of the end joint portion 51 is a shape in which further smaller protrusions are arranged along the corrugated line shown in the first embodiment. By extending the line length of the end joint portion 51 in this way, it is possible to express more efficient cleaning water metabolism and prevention of outflow of polymers, fiber materials, and the like inside the absorbent body due to tearing of the surface sheet 1. .

FIG. 5 is a plan view schematically showing a part of a joining portion as another embodiment (Embodiment 4) in the present invention. Inward projections g ₁ of the distal end portion toward the outside of the sanitary napkin from the end joint 51 joining force is weak region 55 than the end joint 51 except having (in the figure, a region indicated by dots) Is the same as that shown in the first embodiment, and the lower side in the figure is the absorber side. In this embodiment, by having the weakly joined region 55 having a weaker joining force than the end joined portion 51 in the peripheral portion of the end joined portion 51, the inside of the absorbent body due to the above-described efficient cleaning water metabolism and the tearing of the topsheet 1 And prevention of the outflow of the polymer, fiber material, and the like. Further, when excessive pressure is applied at the time of cleaning, there is an effect that the inner side of the weakly bonded region 55 is peeled off and the entire seal portion is prevented from being peeled off.
In this peeling portion, the discharge of cleaning water can be promoted extremely and the hydraulic pressure applied to the joint during cleaning can be remarkably reduced, so that the cleaning performance is improved and the entire joint is prevented from peeling off. . The length (longitudinal direction length) of the weakly bonded region 55 is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.5 mm. Moreover, 0.1-1 mm is preferable and, as for the width | variety (width direction length) of joining area | region 6 ', 0.2-0.5 mm is further more preferable.

FIGS. 6 to 8 are plan views schematically showing a part of a joining portion as another embodiment (Embodiments 5 to 7) in the present invention. In a plan view, the joining portion has a joining form in which an uneven shape composed of an outer projection g ₂ and an inward projection g ₁ spaced at least two different distances from the edge of the absorber is appropriately arranged. Thus, while enhancing the cleaning effect at the time of cleaning, and imparting aesthetics or functional information transmission to the joint portion, there is an effect of relieving the psychological burden at the time of use or cleaning of the user.

  Examples of the surface sheet 1 used in the present invention include, but are not limited to, a nonwoven fabric, a spunbond nonwoven fabric, a meltblown nonwoven fabric, a spunlace nonwoven fabric, a heat roll nonwoven fabric, and a needle punched nonwoven fabric manufactured by the card method. In particular, from the viewpoint of touch, an air-through nonwoven fabric, a heat-embossed nonwoven fabric, an air-laid nonwoven fabric, a needle punched nonwoven fabric, etc. in which a heat-sealing point between fibers is formed on a fiber web obtained by a card method or the like by an air-through method is particularly preferred Particularly preferably used. As a constituent fiber of the surface sheet 1, for example, various liquid-permeable sheet materials such as a nonwoven fabric and an apertured film can be used, and are made of a heat-fusible fiber or a heat-fusible resin, particularly a thermoplastic polymer material. Preferably it contains fibers. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. A core-sheath type composite fiber or a side-by-side type composite fiber made of a combination of these thermoplastic polymer materials can also be suitably used. The topsheet 1 may contain, as part of the constituent fibers, fibers other than the heat-fusible fibers that do not have heat-fusible properties.

  The side sheet 5 is preferably a water-repellent nonwoven fabric, and is water-repellent from a nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, spunlace nonwoven fabric, heat roll nonwoven fabric, needle punch nonwoven fabric, etc. manufactured by the card method. Various non-woven fabrics can be used. Particularly preferably, for example, a spunbond nonwoven fabric, a spunbond-meltblown (SM) nonwoven fabric, a spunbond-meltblown-spunbond (SMS) nonwoven fabric, or the like is used.

  As the absorbent body 3 of the sanitary napkin 10, what is used for this kind of article can act arbitrarily, for example, a fiber layer is covered with a core wrap sheet, or contains a water-absorbing polymer inside Or a thin sheet. The fiber layer and core wrap sheet forming material, for example, as the fiber material constituting the absorbent core, natural fibers such as wood pulp and plant pulp such as softwood pulp and hardwood pulp, regenerated fibers such as cupra and rayon, acetate And the like, and synthetic fibers such as polyolefins, polyamides, and polyesters can be used. One of these can be used alone, or two or more can be used in combination.

  When the sanitary napkin 10 is washed with water, from the viewpoint that blood adhering to the napkin is likely to flow out quickly, the natural fiber may contain a modified pulp obtained by subjecting the natural fiber to a crosslinking treatment. preferable. That is, the absorbent body 4 has a laminated structure in which a plurality of layers made of fiber assemblies are laminated, and a water-absorbing polymer is interposed between opposing layers in the laminated structure, and the fiber assemblies are modified. It is preferred to include pulp and natural fibers (preferably softwood and / or hardwood pulp). As a modified pulp, the below-mentioned crosslinked cellulose fiber and mercerized pulp can be used.

  The ratio of the modified pulp in the total fibers contained in the absorbent body 3 is preferably 20 to 100% by mass, more preferably 35 to 80% by mass. Moreover, the ratio of the natural fibers such as softwood pulp in the total fibers contained in the absorbent body 3 is preferably 0 to 80% by mass, and more preferably 20 to 55% by mass. Moreover, it is possible to contain a hygroscopic agent, a deodorizing agent, etc. in the absorber 3 as needed. Examples of the hygroscopic agent include silica gel, and examples of the deodorizer include activated carbon, activated clay, and a silver-containing compound.

As the water-absorbing polymer, those used for this type of article can be adopted, but a particularly easy-to-clean polymer is preferable. The easy-cleaning polymer means a water-absorbing polymer having an action of easily removing dirt during cleaning, and typically, a water-absorbing polymer described in JP 2010-17536 A is preferably used. This easily washable polymer is obtained by further subjecting a water-absorbing polymer having a carboxy group and / or a carboxylate group and having been subjected to a surface crosslinking treatment to a surface crosslinking treatment and a neutralization treatment in this order. The easily washable polymer thus obtained has a specific range of neutralization degree, a centrifugal retention amount, and physical properties in a specific range (water absorption rate by vortex method, water absorption rate by DW method, bulk specific gravity, pressure at 2.0 KPa) Or a liquid passing speed, absorption amount under pressure at 2.0 KPa). Due to this physical property, the easily washable polymer can easily remove hemoglobin in menstrual blood, and the water absorption speed can be controlled to suppress unnecessary breakage of the absorbent body 3 due to rapid swelling.
The water-absorbing polymer 32 used in the present invention has the above carboxy group and / or carboxylate group, has a neutralization degree of 75 mol% or more, and a centrifugal retention amount in accordance with JIS K 7223 is 5 to 20 g / g. It is preferred to include some easily washable polymer.

By setting the neutralization degree of the easy-cleaning polymer to 75 mol% or more, hemoglobin which is a red component in menstrual blood can be easily removed. When the easily washable polymer is an acrylic acid cross-linked polymer, the degree of neutralization is preferably 75 to 95 mol%, and more preferably 80 to 90 mol%. Although the phenomenon that occurs between the water-absorbing polymer having a neutralization degree of 75 mol% or more and hemoglobin is not clear, the neutralization degree of the water-absorbing polymer composed of the acrylic acid cross-linked polymer is 75 mol% or more, When the absorbent article is washed with water, the pH in the vicinity of the molecular chain of the water-absorbing polymer is higher than the isoelectric point of hemoglobin (usually pH 6.8 to 7), so that electric repulsion occurs between the water-absorbing polymer and hemoglobin. As a result of this, the adhesion rate or adhesion strength of hemoglobin to the water-absorbing polymer is reduced, and it is assumed that hemoglobin is easily detached by washing with water. In addition, the measuring method of the said neutralization degree and its adjustment can use the method of Unexamined-Japanese-Patent No. 2010-17536.
By suppressing the centrifugal retention amount of the easy-cleaning polymer to 5 to 20 g / g, the inherent absorption performance of the polymer can be maintained, and absorption and retention such as menstrual blood can be moderately suppressed to facilitate the removal of redness. . It is more preferable that the amount of centrifugal retention is 7 to 15 g / g. In addition, the measuring method of the said centrifugation holding | maintenance amount and its adjustment can use the method as described in Unexamined-Japanese-Patent No. 2010-17536.

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). It is most preferable to use a moisture permeable film alone as a leak-proof material from the viewpoint of cost and matching with an anti-displacement adhesive. As the film material in this case, a film obtained by melt-kneading a thermoplastic resin and an inorganic filler that is not compatible with the thermoplastic resin and extruding the film to a predetermined size to make fine holes, or essentially moisture The non-porous film which is highly compatible and can discharge water vapor, such as a permeable membrane. 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, in order to be able to use without trouble, 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 >. Moreover, a preferable inorganic filler compounding quantity is 30-65 mass% as a mass% of the filler with respect to the mass of the whole film, More preferably, it is 40-60 mass%.

  In the sanitary napkin 10, although not shown, waterproof sheets may be disposed on both sides in the width direction of the absorbent body 3. The waterproof sheet is arranged on both the left and right sides of the absorbent body 3 so as to cover the skin surface side, the non-skin surface side and the side surface of the absorbent body 3, thereby more effectively preventing the side leakage of menstrual blood and washing water. It is preferable because it can be suppressed. The material used to form this waterproof sheet can be arbitrarily selected from those used for this type of article, such as a liquid-impermeable resin film, a paper laminated with a resin film, and a spunbond / meltblown / spunbond nonwoven fabric. (SMS nonwoven fabric) etc. can be used.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, the absorbent article of the present invention may not include the leak-proof groove 7, the adhesive part (not shown), the blade part 42, and the rear flap part, etc. included in the above embodiment. You may have. Each of the blade portion 42 and the rear flap portion is a portion that extends outward from the both side edges in the longitudinal direction of the absorbent body 4, and the blade portion 42 is normally excreted so as to face the excretion portion of the napkin wearer. The rear flap portion is located behind the blade portion 42 in the longitudinal direction of the napkin.

  The absorbent article of the present invention is not limited to sanitary napkins, and can also be applied to disposable diapers, incontinence pads, urine-absorbing pads, pet diapers, pet sheets, and the like. As the easy-cleaning polymer used in the present invention, the water absorption ratio is suppressed by adjusting the centrifugal retention amount to the specific range, and the liquid passing rate under pressure at 2.0 kPa is the specific range. Since the liquid flow rate under pressure is high when it is adjusted to, the absorption rate under repetition or pressure is very fast, and the liquid can diffuse quickly to the details of the absorber, Even if it swells, there is little so-called gel feeling, which leads to an improvement in discomfort when worn.

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorber 31 End part 4 Side sheet 5 Joining part of peripheral area 51 End joining part 6 Peripheral area 61 Outer peripheral edge 7 Leak-proof groove W Polymer reservoir 10 Sanitary napkin

Claims (4)

A vertically long absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
In the peripheral region of the absorbent article, the front sheet and the back sheet have a joint part joined without an absorber, and at least the joint part in the peripheral region of the longitudinal front and rear ends of the absorbent article is , The uneven shape in plan view is continuous ,
The concavo-convex-shaped joint portion is a concave portion facing the inner side of the end portion of the article as a weak joint, and a convex portion facing the outer side of the end portion of the article is relatively stronger than the weak joint portion. absorbent article.   The absorbent article according to claim 1, wherein the joint portion is formed by heat sealing. The absorptive article according to claim 1 or 2 whose shape of plane view of said joined part is corrugated. The absorbent includes a water-absorbing polymer, and the water-absorbing polymer has a carboxyl group and / or a carboxylate group and has a neutralization degree of 75 mol% or more and a centrifugal retention amount of 5 to 20 g in accordance with JIS K 7223. the absorbent article of claim 1-3, wherein the easy-clean properties of the water-absorbing polymer is a / g.

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