JP5809784B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as sanitary napkins, panty liners, and incontinence pads for absorbing menstrual blood and vaginal discharge, etc., and relates to an absorbent article that allows body fluid to permeate the absorbent body quickly and prevent reversal. .

  Conventionally, as absorbent articles such as panty liners, sanitary napkins, and incontinence pads, a cotton-like shape is formed between a liquid-impermeable back sheet such as a polyethylene sheet or a polyethylene sheet laminated nonwoven fabric and a liquid-permeable surface sheet such as a nonwoven fabric. What intervened the absorber which consists of pulp etc. is known.

If the liquid-permeable surface sheet has a high weight per unit area (for example, 30 g / m ² or more), the amount of menstrual blood held on the surface material increases and causes surface stickiness. It is preferable to lower the basis weight.

However, when the surface sheet has a low basis weight (for example, less than 30 g / m ² ), there is a problem that the concealment property of menstrual blood absorbed by the absorbent body is reduced and the menstrual blood absorbed by the absorbent body is easily visible from the surface. It was. For this reason, an absorbent article has been proposed in which a second sheet such as a porous film is disposed between the top sheet and the absorbent to make it difficult to visually recognize menstrual blood absorbed by the absorbent.

  Patent Document 1 below discloses an absorbent article in which a barrier layer is provided between a fluid storage region and a top sheet, and the barrier layer is made of a hydrophilic film material (Patent Document 1). And claim paragraph [0042]).

  Moreover, in the following patent document 2, it has a two-layer structure of an upper fiber layer located on the front surface side and a lower fiber layer located on the back surface side, and is surrounded by two layers that respectively extend from the front surface side toward the back surface side. The surface sheet of the absorbent article in which a large number of openings are formed, and different hydrophilic treatment agents are used for the two layers, and the lower fiber layer is more liquid than the upper fiber layer. A surface sheet of an absorbent article is disclosed in which the surface tension of the liquid is liable to change due to contact with the liquid (claim 1 of Patent Document 2).

Japanese Patent Laid-Open No. 2004-500932 JP 2006-255051 A

  However, in the absorbent article described in Patent Document 1, when the hydrophilic treatment applied to the barrier layer (second sheet) is uniformly applied throughout, as shown in FIG. Since the movement of menstrual blood in the plane due to the gradient does not occur, menstrual blood tends to accumulate in the flat portion between the opening portions of the second sheet (barrier layer), and the surface tension of menstrual blood collected on this flat portion causes A menstrual film that closes the opening was easily formed in the opening formed in the second sheet. In addition, the surface sheet of the absorbent article described in Patent Document 2 is also subjected to different hydrophilic treatments in the two fiber layers, but the upper fiber layer on the surface side directly touched by menstrual blood is described in Patent Document 1 and the above. Similarly, since a uniform hydrophilic treatment is performed over the entire surface, a menstrual blood film is easily formed in the opening portion as described above.

  The formation of such a menstrual film is particularly remarkable in the case of menstrual blood having a high viscosity. When such a menstrual blood film is formed, the transition of menstrual blood through the opening portion is blocked, and the permeability of menstrual blood is lowered, resulting in a slow absorption rate. In addition, the formation of the menstrual blood membrane has caused menstrual blood that is not absorbed between the top sheet and the second sheet to be held, and a problem has arisen that the menstrual blood held in the intermediate portion is reversed.

  Accordingly, the main problem of the present invention is that an absorbent body is interposed between the liquid-permeable top sheet and the liquid-impervious back sheet, and a second sheet is provided between the top sheet and the absorbent body, In the absorbent article in which the top sheet is a non-woven sheet and the second sheet is a plastic film, an object of the present invention is to provide an absorbent article that quickly transmits body fluid to the absorbent side and prevents reversal.

In order to solve the above problems, as the present invention according to claim 1, an absorbent body is interposed between the liquid-permeable top sheet and the liquid-impervious back sheet, and the top sheet and the absorbent body In an absorbent article with a second sheet in between,
The top sheet is a non-woven sheet, and the second sheet is a plastic film,
Said second sheet, said plurality of openings having a side wall which protrudes on the back sheet side from the top sheet side is formed, the hydrophilic process is performed on the flat portion between the front Symbol opening portion and the open hole section by hydrophilicity of the opening together with is larger than the hydrophilicity of the flat portion between the openings, hydrophilicity of the flat portion is set larger than the hydrophilicity of the topsheet, the relationship between the hydrophilicity of the second sheet and said topsheet, said hydrophilicity of the topsheet <hydrophilicity of the flat portion of the second sheet <is set to relations of hydrophilicity of each of the opening portions of the second sheet, In addition , the absorbent article is characterized in that the surface sheet has a fiber density in a portion corresponding to the opening portion of the second sheet being denser than a fiber density in a portion corresponding to the flat portion of the second sheet. The

  In the invention according to claim 1, the second sheet disposed between the top sheet and the absorber is formed with a large number of apertures provided with side walls protruding from the top sheet side to the back sheet side, By applying a hydrophilic treatment to this aperture, and setting the hydrophilicity of this aperture greater than the hydrophilicity of the flat portion between the apertures, menstrual blood drawn to the aperture by the hydrophilicity gradient The fluid flows through the side wall of the aperture without moving to the aperture edge and quickly moves to the absorber. Accordingly, the menstrual blood film that closes the opening portion is not formed by the surface tension of menstrual blood collected at the opening edge of the opening portion, and the opening is blocked and the movement of menstrual blood is inhibited. Can prevent the situation.

  In addition, due to the hydrophilicity gradient in the plane of the second sheet, the menstrual blood on the second sheet becomes fluid from the flat part to the opening part, and menstrual blood does not accumulate in the flat part. Reversal can be prevented.

  Furthermore, in the present invention, the hydrophilicity of the flat portion is set to be greater than the hydrophilicity of the topsheet, and the hydrophilicity of the aperture is set to be greater than the hydrophilicity of the flat portion, whereby the second sheet The relationship between the hydrophilicity of the top sheet and the top sheet is set such that the top sheet <the flat portion <the aperture portion.

  By setting the hydrophilicity in the order of the topsheet, the flat portion, and the opening portion, menstrual blood absorbed by the topsheet is drawn to the second sheet side by the hydrophilicity gradient with the flat portion, The holes are collected by the hydrophilicity gradient with respect to the aperture, and move to the absorber through the aperture. Thus, by setting the relationship between the hydrophilicity levels of the sheets, menstrual blood can be quickly absorbed by the absorber.

Furthermore, in the present invention, the surface sheet has a fiber density at a portion corresponding to the opening portion of the second sheet higher than that at a portion corresponding to the flat portion of the second sheet .

Therefore, the surface sheet has been absorbed by the surface sheet due to the density relationship of the surface sheet by making the fiber density of the portion corresponding to the aperture portion of the second sheet denser than the fiber density of the portion corresponding to the flat portion. The blood can be drawn toward the opening, and can be quickly absorbed by the absorber through the opening.

As the present invention according to claim 2, wherein the opening portion is absorbent article of claim 1 Symbol placement found the following size of apertures in the distal end side than the size of the opening of the base end side is set to be smaller Provided.

In the invention according to claim 2 , the movement of the body fluid from the surface side to the absorber side is good by setting the size of the opening on the distal end side to be smaller than the size of the opening on the proximal end side. At the same time, the body fluid absorbed by the absorber can be prevented from returning.

  As described above in detail, according to the present invention, it is possible to provide an absorbent article in which body fluid is quickly permeated through the absorbent body to prevent reversion.

It is a partially broken perspective view of sanitary napkin 1 concerning the present invention. It is the II-II arrow directional view. 3 is an enlarged plan view of a second sheet 6. FIG. It is the II-II arrow directional view of FIG. 1 which concerns on another form. It is sectional drawing which shows the absorption state of the bodily fluid by the conventional sanitary napkin.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Reference form example of sanitary napkin 1)
The sanitary napkin 1 is mainly used for panty liners, sanitary napkins, cage sheets, incontinence pads and the like. For example, as shown in FIG. 1 and FIG. Absorbent body comprising a liquid-permeable back sheet 2, a liquid-permeable surface sheet 3 that allows permeation of menstrual blood or a cage, and cotton-like pulp or synthetic pulp interposed between the two sheets 2 and 3 4, an encapsulating sheet 5 surrounding the absorbent body 4, and a second sheet 6 disposed between the liquid-permeable surface sheet 3 and the absorbent body. Around the absorber 4, the liquid-impervious back sheet 2 and the liquid-permeable top sheet 3 are bonded by a bonding means such as a hot melt adhesive.

  As the liquid-impermeable back sheet 2, a sheet material having at least water shielding properties such as an olefin resin sheet such as polyethylene or polypropylene is used. In addition, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet or the like, or A nonwoven fabric sheet (in this case, the waterproof film and the nonwoven fabric constitute a liquid-impervious back sheet) can be used after substantially impervious to liquid imperviousness by interposing a waterproof film. In recent years, those having moisture permeability tend to be used from the viewpoint of preventing stuffiness. This water- and moisture-permeable sheet material is a microporous sheet obtained by forming a sheet by melting and kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, and then stretching in a uniaxial or biaxial direction. It is.

  Next, a non-porous nonwoven fabric is preferably used for the liquid-permeable surface sheet 3. Examples of the material fibers constituting the nonwoven fabric include synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a lace method, a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of being bulky and soft.

In particular, in the present invention, in order to rapidly absorb the highly viscous menstrual blood or the like, as the liquid-permeable topsheet 3, a basis weight 30 g / m ² or less, preferably use a low basis weight of 15 to 30 g / m ² It is preferable to do.

  The absorbent body 4 interposed between the liquid-impervious back sheet 2 and the liquid-permeable top sheet 3 is made of, for example, fluffy pulp and a water-absorbing polymer. The water-absorbing polymer is mixed in the pulp constituting the absorber, for example, as granular powder. Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. It is preferably used in terms of price.

  Further, synthetic fibers may be mixed in the absorbent body 4. As the synthetic fiber, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used. It may be a mixture. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be used. In the case of a hydrophobic fiber, it is desirable to use a synthetic fiber that has been surface-treated with a hydrophilizing agent so as to have an affinity for body fluids.

  When providing the encapsulating sheet 5 surrounding the absorbent body 4 as in this example, as a result, the encapsulating sheet 5 is interposed between the liquid-permeable surface sheet 3 and the absorbent body 4, A body fluid is quickly diffused by the encapsulating sheet 5 having excellent absorbability, and reversal of menstrual blood and the like is prevented.

(About the second seat 6)
In the sanitary napkin 1 according to the present invention, the second sheet 6 is formed with a large number of apertures 10, 10... Each having a side wall 10a protruding from the top sheet 3 side to the back sheet 2 side. The opening portions 10, 10... Are subjected to a hydrophilic treatment, and the hydrophilicity of the opening portions 10 is set larger than the hydrophilicity of the flat portion 11 between the opening portions 10, 10.

  For this reason, conventionally, when a second sheet in which a large number of apertures are formed is disposed between the top sheet and the absorbent body, a menstrual membrane is formed so as to close the aperture, and the menstrual permeability is Although there was a problem of reduction or reversal of menstrual blood held between the top sheet and the second sheet (see FIG. 5), in the sanitary napkin 1 according to the present invention, the opening portion 10 of the second sheet 6, 10 is subjected to a hydrophilic treatment, and the hydrophilicity of the aperture 10 is set to be greater than the hydrophilicity of the flat portion 11, so that menstrual blood drawn to the apertures 10, 10 by the hydrophilicity gradient is opened. The fluid flows through the side wall 10a of the aperture 10 without moving to the hole edge and quickly moves to the absorber 4. Therefore, a menstrual film that closes the opening portion is not formed by the surface tension of menstrual blood collected at the opening edge of the opening portion, and the opening is blocked and the movement of menstrual blood is inhibited. Can prevent the situation.

  In addition, due to the hydrophilicity gradient between the aperture 10 and the flat portion 11, fluidity of the menstrual blood on the second sheet 6 occurs from the flat portion 11 toward the aperture 10, and menstrual blood accumulates in the flat portion 11. Eliminating menstrual blood can be prevented.

  In the second sheet 6, the flat portion 11 can also be subjected to a hydrophilic treatment so that the hydrophilicity of the aperture 10 is set larger than the hydrophilicity of the flat portion 11. In this case, a hydrophilicity gradient can be arbitrarily set between the flat portion 11 and the aperture portion 10, and the menstrual blood fluidity from the flat portion 11 to the aperture portion 10 is arbitrarily changed. Will be able to.

The second sheet 6 is a plastic film, and specifically, a polyolefin film such as polyethylene or polypropylene, a polyester film, a polyamide film, or the like can be used. The second sheet 6 is preferably made of a film material that is opaque and / or printed with a pattern or the like in order to make it difficult to visually recognize menstrual blood absorbed by the absorbent body 4. It is preferable that the second sheet 6 is relatively thin with a basis weight of 15 to 30 g / m ² , a thickness of 0.5 mm or less, and has a smooth surface, so that the second sheet 6 can be easily adhered to the top sheet 3 and the absorber 4.

  The second sheet 6 is made opaque by adding pigments and fillers such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc, and barium sulfate into an olefin resin or plastic to form a film. Preferably used.

  In order to perform the hydrophilic treatment on the opening 10 of the second sheet 6, the opening 10 is formed by pin embossing in which a hydrophilic agent is previously applied to the tip of the pin, whereby the side wall 10a and the base of the opening 10 are formed. The hydrophilic agent can be applied only to the end opening edge and the vicinity thereof. The above-mentioned “base end side opening edge and the vicinity thereof” mean to include a peripheral edge where the inclination from the flat part of the second sheet 6 to the opening part 10 starts and a part slightly extending from the peripheral part to the flat part side. . Moreover, what is necessary is just to use the 2nd sheet | seat 6 to which the hydrophilic process was given over the whole sheet | seat in order to give a hydrophilic process to the said flat part 11. FIG.

  As said hydrophilic agent, what has alkyl phosphoric acid ester salt (octyl, dodecyl type), propylene glycol, ethylene glycol monobutyl ether, polyoxyalkylene alkyl ether, etc. as a main component can be used suitably, 0.3- It is desirable that the aqueous solution has a concentration of 3.0%, preferably 1.0 to 1.5%.

  In order to set the hydrophilicity of the aperture 10 larger than the hydrophilicity of the flat portion 11, it is possible to vary the amount of hydrophilic agent to be applied or to apply hydrophilic agents having different components.

As the opening 10, _(L 1 in FIG. 2 and FIG. 3, _{L 2)} opening dimensions 0.25~0.75mm, 5~50% its opening ratio of the surface area of the second sheet 6 , Preferably 20-30%. The planar shape of the opening 10 is preferably a polygon such as a hexagon as shown in FIG. 3, but it may be a circle, an ellipse, or the like.

Further, as shown in FIGS. 2 and 3, the opening portion 10 has an opening on the distal end side (absorber 4 side) from the opening size L ₁ on the base end side (surface sheet 3 side). are preferably formed so as towards the size L ₂ is decreased. Thereby, menstrual blood permeates from the topsheet 3 side to the absorbent body 4 quickly, and menstrual blood absorbed by the absorbent body 4 is less likely to return to the topsheet 3 side.

  Further, as the relationship between the hydrophilicity of the second sheet 6 and the topsheet 3, the hydrophilicity of the flat portion 11 is set larger than the hydrophilicity of the topsheet 3 and the hydrophilicity of the aperture 10 is flat. It can be set larger than the hydrophilicity of 11. That is, the hydrophilicity of each part of the top sheet 3 and the second sheet 6 is set in a relation of top sheet 3 <flat part 11 <opening part 10. In addition, the relationship of the hydrophilicity between each part of the top sheet 3 and the second sheet 6 is top sheet 3 <open hole 10 and top sheet 3 <flat part 11. Thereby, menstrual blood absorbed by the top sheet 3 is attracted to the second sheet 6 side by the hydrophilicity gradient with the flat portion 11 and is collected to the aperture 10 by the hydrophilicity gradient with the aperture 10. Then, it moves to the absorber 4 through the opening 10. Therefore, by setting the relationship between the hydrophilicity levels of the sheets, menstrual blood can be promptly absorbed by the absorbent body.

  By the way, as shown in FIG. 4, the surface sheet 3 is opened by forming a compressed portion 3 a on the surface side (skin contact surface side) of the portion corresponding to the opening portion 10 of the second sheet 6. It is preferable that the fiber density of the part corresponding to the hole 10 is made denser than the fiber density of the part corresponding to the flat part 11. By forming the pressing parts 3a, 3a ... on the surface sheet 3, the menstrual blood absorbed by the surface sheet 3 due to the density relationship of the surface sheet 3 can be drawn toward the aperture 10 and absorbed through the aperture 10 Menstrual blood is quickly absorbed by the body 4. In addition, it is preferable that the back surface side (the contact surface side with the second sheet 6) of the top sheet 3 is flat and a contact area with the second sheet 6 is secured. As a result, menstrual blood can be quickly transferred using the fiber gradient between these sheets. In order to obtain the surface sheet 3 in which the compressed parts 3a, 3a, ... are formed only on the surface side, the surface sheet is provided between a pattern embossing roll having a large number of convex portions on the surface and a flat anvil roll having a flat surface. Lead 3 and give emboss. The pressing portion 3a is processed by the top sheet 3 alone before being bonded to the second sheet 6.

  DESCRIPTION OF SYMBOLS 1 ... Sanitary napkin, 2 ... Back sheet, 3 ... Front sheet, 3a ... Pressing part, 4 ... Absorber, 5 ... Encapsulating sheet, 6 ... Second sheet, 10 ... Opening part, 10a ... Side wall, 11 ... Flat Part

Claims (2)

In the absorbent article provided with a second sheet between the surface sheet and the absorbent body, an absorbent body is interposed between the liquid-permeable top sheet and the liquid-impermeable back sheet,
The top sheet is a non-woven sheet, and the second sheet is a plastic film,
Said second sheet, said plurality of openings having a side wall which protrudes on the back sheet side from the top sheet side is formed, the hydrophilic process is performed on the flat portion between the front Symbol opening portion and the open hole section by hydrophilicity of the opening together with is larger than the hydrophilicity of the flat portion between the openings, hydrophilicity of the flat portion is set larger than the hydrophilicity of the topsheet, the relationship between the hydrophilicity of the second sheet and said topsheet, said hydrophilicity of the topsheet <hydrophilicity of the flat portion of the second sheet <is set to relations of hydrophilicity of each of the opening portions of the second sheet, And the said surface sheet makes the fiber density of the site | part corresponding to the opening part of the said 2nd sheet denser than the fiber density of the site | part corresponding to the flat part of the said 2nd sheet | seat, The absorbent article characterized by the above-mentioned. The opening is, the absorbent article according to claim 1 Symbol placement found the following size of apertures in the distal end side than the size of the opening of the base end side is set smaller.

Images