JP5612825B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article such as a napkin, a panty liner, a cage sheet, and an incontinence pad that eliminates stuffiness, rash, stickiness, and the like by providing significantly higher air permeability than before.

  Conventionally, as an absorbent article N such as a sanitary napkin, a panty liner, a cage sheet, or an incontinence pad, for example, as shown in FIG. 8, a liquid-impermeable back sheet 50 made of a polyethylene sheet or a polyethylene laminated nonwoven fabric or the like. And an absorbent body 52 made of cotton-like pulp or the like is known between a non-woven fabric or a liquid-permeable surface sheet 51 made of a porous plastic sheet.

  Conventionally, in the absorbent article N, various improvements have been made in order to eliminate the stuffiness, rash, and stickiness caused by steam from body fluids.

  For example, in the following Patent Document 1, at least a liquid-permeable top sheet, a first adhesive layer for adhering an absorbent body interposed between the top sheet and the back sheet, the absorbent body and the back sheet, In the absorbent article which has the 2nd adhesive layer which sticks, and the 3rd adhesive layer which sticks the back sheet and underwear, the 1st adhesive in the plane longitudinal direction of the absorber There has been proposed an absorbent article in which a gap (opening) is provided at a position not overlapping with the layer or the third adhesive layer.

Moreover, in the following patent document 2, the main body portion of the absorbent article includes a liquid-absorbing absorbent core, a top sheet that covers the main surface of the absorbent core on the wearer side, and a back sheet that covers the other main surface of the absorbent core. The backsheet includes a rear part facing the buttocks of the wearer and a front part facing the abdomen, the rear part being formed of a water-resistant film having air permeability, and the front part is a rear part An absorbent article formed of a water-repellent nonwoven fabric having a water pressure resistance lower than the water pressure resistance is proposed.
Furthermore, in Patent Document 3 below, the leak-proof sheet has a penetrating layer capable of penetrating liquid and a liquid-impervious or liquid-impervious leak-proof layer, and the leak-proof sheet has many fine holes. And the size of the micropores in the permeation layer is larger than the size of the micropores in the leakproof layer, or the number of micropores in the permeation layer is the number of micropores in the leakproof layer. Absorbent articles having more pores have been proposed.

JP 2004-290427 A JP 2006-81563 A JP 2007-20664 A

  The absorptive article concerning the above-mentioned patent documents 1 gives high breathability by forming the crevice (opening) penetrated in the thickness direction of an absorber. In this case, a film having moisture permeability is used as the back sheet, and vapor is allowed to pass therethrough. However, in order for the moisture-permeable plastic film to dissipate water vapor to the outside, it is a condition that the vapor pressure of water vapor generated on the inner side of the absorber is higher than that on the outer side. As long as the water vapor pressure does not increase, there is a problem that water vapor is not effectively diffused.

  According to Patent Document 2, by changing the water pressure resistance value of the backsheet for each part according to the required water pressure resistance performance, the breathability of the absorbent article is prevented while preventing the excrement from leaking from the absorbent article. Is partly improved. However, the front part of the absorbent article has high air permeability, but the rear part uses a water-resistant film with air permeability, so the air permeability at the rear part is still the same as before. is there.

  Further, in Patent Document 3, when a body fluid permeates into the permeation layer, an overwhelming difference occurs in the moisture content between the front and back sides of the sheet, thereby promoting vapor divergence. That is, the amount of moisture on the side facing the wearer's skin is overwhelmingly larger than that on the side facing the underwear, the difference in the amount of moisture becomes the driving force, and the effect of evaporating the penetrated moisture directly as water vapor is effective. Although it becomes high, even if it has air permeability higher than the conventional moisture-permeable film, as long as the moisture-permeable film is used, there is a limit in air permeability.

  Therefore, the main problem of the present invention is to provide a napkin and panty that eliminates the feeling of stuffiness, rash, stickiness, etc. at a higher level by providing a breathability much higher than that of the conventional one using a moisture permeable film as the back sheet. The object is to provide absorbent articles such as liners, cage sheets, and incontinence pads.

In order to solve the above-mentioned problem, in the absorbent article in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet as the present invention according to claim 1,
A plurality of openings penetrating in the thickness direction are formed in the absorber, and the area of one opening is 0.7 to 400 mm ² , and the opening ratio indicating the area ratio of the opening is 5 to 50%.
The back sheet is made of polyethylene or polypropylene olefin-based synthetic fibers, and a water-repellent nonwoven fabric in which a water-repellent agent is applied only to the absorber-side surface is used .
The absorbent body is made of an absorbent material mainly composed of pulp fibers and is surrounded by crepe paper, and an opening is formed together with the crepe paper, and the crepe paper on the upper surface side and the lower surface side are formed on the side wall surface of each opening. An absorbent article characterized in that it is bonded to a crepe paper is provided.

In the present invention described in claim 1, a plurality of openings penetrating in the thickness direction are formed in the absorber, and the area of one opening is 0.7 to 400 mm ² , and the opening ratio indicating the area ratio of the opening is 5 As the back sheet, a water-repellent nonwoven fabric made of olefin-based synthetic fibers of polyethylene or polypropylene and having a water-repellent agent applied only to the absorber-side surface is used. Therefore, in the absorbent article according to the present invention, since the vapor is quickly dissipated through the water repellent nonwoven fabric used as the opening and the back sheet formed in the absorbent body, the breathability is much higher than the conventional one. It has a high level of ability to eliminate stuffiness, rash and stickiness. In addition, when bodily fluid is discharged, if the bodily fluid passes through the liquid-permeable surface sheet and flows into the opening of the absorbent body, it forms a polka dot by contact with the water-repellent nonwoven fabric that forms the back sheet, and rolls up and absorbs within the opening. When it comes into contact with the side wall surface of the body opening, it is quickly absorbed by the absorber. Therefore, except when a large amount of body fluid is discharged, body fluid does not leak even if a water-repellent nonwoven fabric is used as the back sheet.

In the absorber, the area of one opening is 0.7 to 400 mm ² , and the opening ratio indicating the area ratio of the opening is 5 to 50%.

  If the opening area is too large, it takes time until body fluid is absorbed from the side wall surface of the absorber opening, and leakage tends to occur. If it is too small, the air permeability is insufficient, so one opening area is appropriate. When the range is too large and the aperture ratio is too large, the volume of the absorber is reduced and the absorption capacity is lowered. When the aperture ratio is too small, the air permeability becomes insufficient, and thus the appropriate range of the aperture ratio is defined.

Further, the absorbent body is made of an absorbent material mainly composed of pulp fibers, surrounded by crepe paper, and has openings formed with the crepe paper. The crepe paper on the side is joined.

  In the case of using pulp fibers that have been generally used as the absorbent material, in order to maintain the shape of the opening and prevent the fibers from being scattered in the opening, the upper surface side of the side wall of each opening The crepe paper and the crepe paper on the lower surface side are preferably joined.

  As the present invention according to claim 2, the absorber includes an intermediate region including a body fluid discharge site, a front region located on the front side of the intermediate region, and a rear region located on the rear side of the intermediate region. The absorbent article according to claim 1, wherein the opening ratio in the intermediate region is set to be relatively smaller than that of the front region and the rear region.

  In the present invention described in claim 2, the aperture ratio of the absorber is changed for each part of the absorber. Specifically, the intermediate region including the body fluid discharge site is required to have an absorption capacity, so the aperture ratio is set low, and the absorber volume is increased so that more body fluid can be absorbed. In the region, it is desirable to set a relatively large aperture ratio with emphasis on air permeability.

  As described in detail above, according to the present invention, it is possible to give a much higher breathability than those using a moisture-permeable film as a back sheet, so that stuffiness, rash, stickiness, etc. are eliminated at a high level It becomes possible to do.

1 is a partially broken perspective view of an absorbent article 1 according to the present invention. It is the II-II arrow directional view of FIG. (A) is an enlarged cross-sectional view of the main part showing the ventilation state, and (B) is an enlarged cross-sectional view of the main part showing the absorption state of the body fluid. (A)-(D) are figures which show the example of a shape of opening. It is an absorber top view which shows the other example of opening formation pattern (the 1). It is an absorber top view which shows the other example of opening formation pattern (the 2). It is a principal part expanded sectional view which shows another modification. It is an expanded view of the conventional sanitary napkin N.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The absorbent article 1 is mainly used for applications such as panty liners, sanitary napkins, cage sheets, and incontinence pads. For example, as shown in FIG. 1, a back sheet 2 and a liquid-permeable surface The absorber 4 is interposed between the sheet 3 (hereinafter also simply referred to as a surface sheet), and in the present invention, a plurality of openings 4a, 4a,. In addition, a water-repellent nonwoven fabric is used as the back sheet 2. Around the absorber 4, the back sheet 2 and the top sheet 3 are bonded by an adhesive means such as a hot melt adhesive or heat seal. The absorber 4 may be covered with crepe paper. In this case, the opening 4a is formed together with the crepe paper.

Hereinafter, the absorbent article 1 will be described in detail.
As the surface sheet 3, a non-porous or perforated nonwoven fabric or a porous plastic sheet is used.

  Examples of the material fibers constituting the non-woven fabric include synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton. In addition, composite fibers such as a core-sheath fiber, a side-by-side fiber, and a split fiber that have a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be suitably used. As for the processing method, a nonwoven fabric obtained by an appropriate processing method such as an air-through method, a spunlace method, a spunbond 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 air-through method and the thermal bond method are excellent in terms of being bulky and soft. Moreover, the nonwoven fabric which consists of synthetic fibers is used suitably at the point which is easy to give embossing.

As the material for the porous plastic sheet, for example, an olefin resin such as polyethylene or polypropylene is preferably used, but a polyamide resin such as polyester or nylon, EVA, or the like can also be used. The pore diameter of the porous plastic sheet is 0.05 to 3.0 mm, preferably 0.1 to 2.0 mm, more preferably 0.5 to 1.5 mm, and the number of apertures is 100 to 500. / Cm ² , preferably about 200 to 400 / cm ² . In order to form the openings, the synthetic resin sheet is softened near the softening temperature and is positioned on the upper surface of the support having a large number of openings, and is sucked from below the support, There are a method of pressurizing air pressure from the upper surface and a method of stretching and opening the sheet material after impressing a large number of slits on the synthetic resin sheet material.

Further, in the case of the porous plastic sheet, although depending on the opening diameter, there is a case where a phenomenon that it is difficult to move from the opening portion to the absorber 4 side due to its hydrophobicity may be seen. It is desirable to apply a surfactant with a basis weight of 1.20 g / m ² or more so that the body fluid can easily migrate from the aperture to the absorber 4.

On the other hand, the back sheet 2 is preferably made of a nonwoven fabric made of synthetic fibers such as polyethylene or polypropylene, such as olefins, polyesters, and polyamides, and has a water repellent treatment in order to give particularly high water repellency. A water-repellent nonwoven fabric is used. The water repellent treatment is performed, for example, by applying a silicon-based, paraffin-based, alkylchromic chloride-based water repellent or the like. The water repellent surface is at least the surface on the absorber 4 side. As the processing method, a nonwoven fabric obtained by an appropriate method such as a spunbond method, an SMS method, a melt blown method, a thermal bond method, an air-through method, a point bond method, a needle punch method, etc. can be used. Spunbond nonwovens, meltblown nonwovens and SMS (spunbond / meltblown / spunbond) nonwovens are particularly desirable. The basis weight, preferably from 10 to 100 g / ^{m 2,} more preferably ^{15~70g / m 2, 20~40g / m} 2 is particularly preferred. The thickness is 0.1 to 1.0 mm, preferably 0.3 to 0.7 mm. The water pressure resistance (JIS L 1092) of the back sheet 2 is 100 to 400 mmH ² 0, preferably 150 to 300 mmH ² 0. The moisture permeability (JIS Z 0208) is set to 1500 to 10000 g / m ² · 24 h, preferably 3000 to 7000 g / m ² · 24 h.

The absorbent body 4 is composed of, for example, fluffy pulp fibers and a water-absorbing polymer. The water-absorbing polymer is mixed, for example, as a granular powder in pulp fibers constituting the absorber. Examples of the pulp fiber include cellulose fibers such as chemical pulp obtained from wood and dissolved pulp, and artificial cellulose fibers such as rayon and acetate. Softwood pulp having a longer fiber length functions than hardwood pulp And is preferably used in terms of price. As the absorbent body 4, in addition to pulp fibers, an absorbent material based on a pulp sheet or a sponge-like foamed resin obtained by foaming a resin such as polyurethane can be used. . The pulp sheet is obtained by processing pulp fibers mixed with a superabsorbent resin into a sheet in advance, and has a thickness of 1 to 3 mm. The composition is 10 to ²⁰⁰ g / m ^{2 of} pulp fibers and 0 to 100 g / m2 of superabsorbent resin. ^Two are preferably used.

  Examples of the superabsorbent resin include cross-linked polyacrylate, self-crosslinked polyacrylate, saponified acrylate-vinyl acetate copolymer cross-linked, isobutylene / maleic anhydride copolymer cross-linked, Examples include cross-linked polysulfonates, and partially cross-linked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. In the production process of the highly water-absorbent resin having the water absorption performance, the water absorption force and the water absorption speed can be adjusted by adjusting the crosslinking density and the crosslinking density gradient. In addition, when the high water-absorbing resin content exceeds 50%, the entanglement between the pulp fibers is lost, the sheet strength is lowered, and tearing, cracking, and the like are likely to occur.

As shown in FIG. 1, the absorber 4 is formed with a plurality of openings 4a, 4a... Penetrating in the thickness direction. One opening 4a of the area 0.7~400mm ^2, to preferably it is desirable to 19~100mm ^2, 5~50% opening ratio indicating the area ratio of the opening 4a, and preferably 15% to 30% Is desirable.

  In the present absorbent article 1, a plurality of openings 4 a, 4 a... Penetrating in the thickness direction are formed in the absorbent body 4, and a water-repellent nonwoven fabric is used as the back sheet 2. As shown in FIG. 2, since the vapor is quickly diffused through the water repellent nonwoven fabric used as the opening 4a and the back sheet 2 formed in the absorbent body, it is possible to have a significantly higher air permeability than before. Further, as shown in FIG. 3 (B), when bodily fluid is discharged, when the bodily fluid passes through the top sheet 3 and flows into the opening 4a of the absorbent body 4, the water repellent nonwoven fabric constituting the back sheet 2 When it comes into contact with the side wall surface of the absorbent body opening portion, the absorbent body 4 is quickly absorbed by the absorbent body 4. Therefore, except when a large amount of body fluid is discharged, even if a water-repellent nonwoven fabric is used as the back sheet 2, body fluid does not leak.

The shape of the opening 4a can be an arbitrary shape such as a triangle, a pentagon, a hexagon, and a circle as shown in FIG. 4 in addition to the rectangle shown in FIG. However, the one closer to a circular shape is desirable because the distance to the opening side wall surface becomes shorter.
As shown in FIG. 1, the formation pattern of the openings 4a can be formed with a uniform opening ratio over the entire absorber, but can also be different for each part. In this case, it is desirable to reduce the aperture ratio at a site where absorption capability is required. Specifically, as shown in FIGS. 5 and 6, the absorbent body 4 includes an intermediate region 6 including a body fluid discharge site, a front region 7 positioned in front of the intermediate region 6, and the intermediate region 6. The rear area 8 is also defined on the rear side, and the aperture ratio in the intermediate area 6 is set to be relatively smaller than that of the front area 7 and the rear area 8. In the example shown in FIG. 5, the aperture ratio in the intermediate region 6 is set to be relatively smaller than that in the front region 7 and the rear region 8 by changing the scattered density of the openings 4 a having the same area. In the example shown in FIG. 6, the aperture ratio in the intermediate region 6 is made to be relatively higher than that in the front region 7 and the rear region 8 by changing the area of the opening 4 a while the dotted positions of the openings 4 a are the same. Is also set smaller.

  By the way, when an absorbent body mainly composed of pulp fibers is used as the absorbent body 4, the absorbent body 4 is surrounded by crepe paper in order to maintain the shape. In order to prevent scattering inside the openings, as shown in FIG. 7, when the openings 4a are formed together with the crepe paper, the crepe paper 5A on the upper surface side and the crepe paper 5B on the lower surface side on the side wall surface of each opening 4a It is desirable to join.

  DESCRIPTION OF SYMBOLS 1 ... Absorbent article, 2 ... Back surface sheet, 3 ... Liquid-permeable surface sheet, 4 ... Absorber, 4a ... Opening, 6 ... Middle area | region, 7 ... Front side area | region, 8 ... Rear side area | region

Claims (2)

In the absorbent article in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet,
A plurality of openings penetrating in the thickness direction are formed in the absorber, and the area of one opening is 0.7 to 400 mm ² , and the opening ratio indicating the area ratio of the opening is 5 to 50%.
The back sheet is made of polyethylene or polypropylene olefin-based synthetic fibers, and a water-repellent nonwoven fabric in which a water-repellent agent is applied only to the absorber-side surface is used .
The absorbent body is made of an absorbent material mainly composed of pulp fibers and is surrounded by crepe paper, and an opening is formed together with the crepe paper, and the crepe paper on the upper surface side and the lower surface side are formed on the side wall surface of each opening. An absorbent article characterized by being joined to crepe paper .   The absorber is defined by an intermediate region including a body fluid discharge site, a front region located on the front side of the intermediate region, and a rear region located on the rear side of the intermediate region. The absorbent article according to claim 1, wherein an opening ratio in an intermediate region is set smaller than that in the front region and the rear region.

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