JP3998626B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as sanitary napkins and disposable diapers.

In an absorbent article such as a sanitary napkin or a disposable diaper, it is required that effluent from the human body such as menstrual blood or urine is promptly transferred to the absorbent body.
Patent Document 1 describes a technique for manufacturing a sheet having an opening by making a slit in a plastic foam sheet such as polyurethane and then winding it for a predetermined time.
Patent Document 2 describes a surface sheet of an absorbent article that has a large number of convex portions and concave portions, and has openings formed at the top of the concave portions and / or in the vicinity thereof.

JP 62-162499 A JP 2002-238947 A

However, since the aperture sheet obtained in Patent Document 1 is a flat sheet in which apertures are formed, when this is used as a surface sheet, the sheet surface after liquid absorption becomes sticky. .
In the surface sheet of Patent Document 2, when the skin is in close contact with the opening, the opening is likely to be blocked, and therefore the liquid may not be sufficiently transferred to the absorber.

  Therefore, an object of the present invention is to provide an absorbent article that can quickly transfer liquids such as menstrual blood and urine to an absorbent body and can prevent inconvenience such as stickiness due to liquid remaining on the surface. And

  The present invention is an absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent interposed between the two sheets, wherein the top sheet comprises a plurality of internal cavities. The above-mentioned object is achieved by providing an absorbent article having a slit passing through the top.

  Further, the present invention is a surface sheet of an absorbent article comprising an upper layer sheet and a lower layer sheet made of a nonwoven fabric, wherein the upper layer sheet and the lower layer sheet are bonded to each other at a predetermined interval, and a plurality of bonding portions are provided. The upper layer sheet is formed with a convex portion of an internal cavity between the joint portions due to the shrinkage of the lower layer sheet, and the convex portion has a slit passing through the top portion. Is to provide.

  The absorbent article of the present invention can quickly transfer liquids such as menstrual blood and urine to the absorbent body, and can prevent inconvenience such as stickiness due to liquid remaining on the surface.

  The surface sheet of the absorbent article of the present invention has excellent liquid permeability, and can prevent inconvenience such as stickiness due to the liquid remaining on the surface of the surface sheet.

The present invention will be described below based on preferred embodiments with reference to the drawings.
FIG. 1 shows a part of a sanitary napkin 20 as an embodiment of the absorbent article of the present invention.
The napkin 20 includes a liquid-impermeable top sheet 1, a liquid-impermeable back sheet 21, and a liquid-retaining absorbent 22 interposed between the two sheets. The top sheet 1 of the napkin 20 is an embodiment of the top sheet of the absorbent article of the present invention. As the back sheet 21 and the absorbent body 22, a material usually used for this type of article can be used.

The surface sheet 1 of this embodiment has a two-layer structure of an upper layer sheet 2 and a lower layer sheet 3 each made of a fiber assembly.
As shown in FIG. 1, the upper sheet 2 and the lower sheet 3 are intermittently joined in the X direction (one direction) of the top sheet 1 and in the Y direction orthogonal to the X direction, and adjacent to each other. A plurality of convex portions 5 having internal cavities are formed between the joining portions 4 and 4 to be formed. Each joint 4 can be formed by various known joining means such as heat sealing, ultrasonic sealing, and adhesive. The joint portion 4 in the present embodiment is formed in a linear shape between adjacent convex portions, and extends in a direction parallel to the direction in which the convex portions extend. The width of the joint 4 is preferably 0.3 to 3 mm, particularly preferably 0.5 to 1.5 mm.

  Each convex portion 5 extends continuously in the X direction (one direction) of the topsheet 1. To extend continuously in one direction of the surface sheet means that the top of the convex portion 5 is not a dot or a circle but a line or a band having a predetermined length. The continuously extending length of the top of the convex part 5 is preferably 30 mm or more, particularly 50 mm or more, particularly 70 mm or more, including a parted portion by the slit 6 described later. In this embodiment, since the convex part has extended continuously, as shown in FIG. 1, the convex part forms the collar.

It is preferable that the height T (refer FIG. 2) of the convex part 5 is 0.2-5 mm, especially 0.5-3 mm from a viewpoint of the favorable touch and maintenance of a convex part shape.
Further, the convex portion 5 has a width W1 (see FIG. 2) of the upper half 51 of the convex portion 5 of 0.5 to 5 mm, particularly 0.7 to 3 mm, from the viewpoint of good touch and maintenance of the convex shape. It is preferable that the width W2 (see FIG. 2) between the upper half portions 51 of adjacent convex portions is 0.5 to 5 mm, and particularly preferably 0.7 to 2 mm. In addition, as shown in FIG. 2, the upper half part 51 of the convex part 5 is above the wearer's center height position (position which bisects the height T of the convex part 5) P (a wearer's height). It is the part located on the skin side. Further, the height T of the convex portion and the widths W1, W2 are measured from a cross-sectional shape as shown in FIG.

  Each convex part 5 has the slit 6 which passes the top part 53, as shown in FIG. As shown in FIG. 2, the slit 6 extends over both sides of the top portion 53. Each slit 6 has a length L1 (see FIG. 2) perpendicular to the direction in which the convex portion 5 extends (see FIG. 2), which is 70 to 130% of the width W1 of the upper half 51 of the convex portion 5, particularly 90 to 110% is preferable from the viewpoint that the vicinity of the slit 6 is movable in contact with the skin and the number of parts to which the contact with the skin is fixed is small, so that the touch is excellent.

Here, “movable” means that the slit 6 is used when the convex portion 5 independent by the slit 6 falls in a direction perpendicular to the convex portion 5, or the convex portion is crushed or tilted by the movement of the user. It means that it spreads in the movement of the person or the side edge of the slit 6 relatively approaches the lower sheet 3 side.
The slit 6 facilitates this movement, and the side edge thereof is easily brought into contact with the lower layer sheet 3 (absorber 22 when there is no lower layer sheet 3), thereby improving the transferability of the liquid to the absorber 22. From the viewpoint, as shown in FIG. 2, it is preferable that at least one end (preferably both ends 61, 61) reaches the lower half 52 of the convex portion 5, and at least one end (preferably both ends). Is more preferably lower than the height position of 20% of the height T of the convex portion 5, and at least one end thereof (preferably both end portions) is a bottom portion between adjacent convex portions. It is particularly preferable to reach the vicinity of the central portion 54. Here, the bottom center portion 54 particularly refers to an upper portion joined to the lower layer sheet 3.

  The slit 6 in the present embodiment is formed in a direction (Y direction in FIG. 1) orthogonal to the direction (X direction in FIG. 1) in which each convex portion 5 extends. The orthogonal direction is a direction that intersects the direction in which the convex portion 5 extends at an angle of 90 degrees. The slit 6 preferably extends across the direction in which each convex portion 5 extends, and the intersection angle between the direction in which the slit 6 extends and the direction in which the convex portion 5 extends is the intersection angle (90 degrees) in this embodiment. It is preferably within plus or minus 60 degrees, particularly within 45 degrees.

In the present embodiment, a plurality of convex portions 5 continuously extending in one direction (X direction) are formed in a direction orthogonal to the one direction (Y direction), and the slits of adjacent convex portions are convex. They are formed at the same position in the direction (X direction) in which the portion 5 extends.
A form in which the slit formed in one convex part of adjacent convex parts is located in the center part between the slits formed in the other convex part, and the slits are formed in a zigzag shape as a whole is also preferable. It is.
In addition, when forming many slits 6 in one convex part 5, the formation interval of the slits 6 is 5 to 30 mm, in particular 10 to 20 mm. It is preferable from the viewpoint that the liquid is guided to the absorber. In addition, it is preferable that the width | variety (width | variety of the direction orthogonal to the direction where a slit is extended) of a slit is a thing of substantially zero to about 3 mm.

  As for the surface sheet in this invention, it is preferable that the sheet | seat which forms a convex part (henceforth a convex part formation sheet, this embodiment upper sheet 2) is a nonwoven fabric sheet. As the nonwoven fabric sheet used as the convex portion forming sheet, various known nonwoven fabrics can be used, and an air-through nonwoven fabric, an airlaid nonwoven fabric, a heat roll nonwoven fabric, and a spunbond nonwoven fabric are particularly preferable. As the non-woven fabric for the convex portion forming sheet, a non-woven fabric having a multi-layer structure having a plurality of layers but having no voids between layers can be used in addition to the single-layer structure.

  The surface sheet in the present invention preferably has elasticity, and when the surface sheet 1 having a two-layer structure including the upper layer sheet 2 and the lower layer sheet 3 is an elastic sheet as in the present embodiment, the upper layer is used. It is preferable that the sheet 2 is composed of a non-stretchable sheet and the lower layer sheet 3 is composed of a stretchable sheet.

The surface sheet 1 of the present embodiment is composed of an upper layer sheet 2 and a lower layer sheet 3 each composed of a fiber assembly. The fiber assembly is a concept including a nonwoven fabric.
As the upper layer sheet 2 for producing such a two-layer surface sheet 1, for example, a nonwoven fabric formed by a card method, a nonwoven fabric formed by a needle punch method, a nonwoven fabric formed by a solvent adhesion method, a spunbond Nonwoven fabrics formed by the method, nonwoven fabrics formed by the melt blown method, those obtained by converting tow fibers into non-woven fabric by hot embossing, and the like can be used. A knitted fabric or the like can also be used as the upper layer sheet 2. Moreover, materials other than a fiber assembly, for example, a resin film etc., can also be used.

  As the fiber constituting the upper layer sheet 2, a heat-fusible fiber, particularly a fiber made of a thermoplastic polymer material is preferably used. 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 used.

  The fiber assembly constituting the lower layer sheet 3 includes a web formed by a card method, a non-woven fabric formed by a thermal fusion method, a non-woven fabric formed by a hydroentanglement method, a non-woven fabric formed by a needle punch method, and solvent bonding Nonwoven fabric formed by the spunbond method, nonwoven fabric formed by the melt blown method, and the like. A knitted fabric or the like can also be used as the lower layer sheet 3.

The fiber assembly constituting the lower layer sheet 3 preferably includes crimped fibers that are three-dimensionally crimped from the viewpoint of imparting stretchability to the lower layer sheet 3, and in particular, three-dimensional crimps were expressed by heat treatment. It is preferable that a latent crimpable fiber is included. The latent crimpable fiber is a fiber that can be handled in the same manner as a conventional nonwoven fabric fiber before being heated, and has a property that a helical crimp is developed and contracted by heating at a predetermined temperature. is there.
The latent crimpable fiber is composed of, for example, an eccentric core-sheath type composite fiber or a side-by-side type composite fiber containing two types of thermoplastic polymer materials having different shrinkage rates as an example. The thing of 296325 gazette and patent 2759331 gazette is mentioned. As an example of two types of thermoplastic polymer materials having different shrinkage rates, for example, a combination of ethylene-propylene random copolymer (EP) and polypropylene (PP) is preferable in terms of the softness of the topsheet 1.

The upper layer sheet 2 and / or the lower layer sheet 3 may be mixed with water-absorbing fibers such as rayon, cotton, and hydrophilic acrylic fibers.
Moreover, as a constituent fiber of the surface sheet 1, those obtained by hydrophilizing the surface of the synthetic fiber with a surfactant or the like are particularly preferable.

  A method of shrinking the lower layer sheet 3 after joining the upper layer sheet 2 to the lower layer sheet 3 in an expanded state by imparting elasticity to the lower layer sheet 3, or the lower layer sheet 3 before heat shrinking to the upper layer sheet 2 After joining, the surface sheet which concerns on this invention can be easily manufactured by the method of thermally shrinking this lower layer sheet | seat 3. As shown in FIG.

The upper layer sheet (convex part forming sheet) 2 has a basis weight of 15 to 50 g / m ² , particularly 20 to 30 g / m ² , from the viewpoint of securing sufficient strength, ensuring formability, and maintaining the texture. preferable.

  In addition, the surface sheet 1 preferably has a fiber diameter of 0.5 to 6 dtex, particularly 1 to 3 dtex, from the viewpoint of improving the touch, and particularly the surface of the two-layer structure of the upper layer sheet and the lower layer sheet The fiber diameter of the upper layer sheet 2 when obtaining the sheet 1 is preferably 0.5 to 3 dtex.

The upper layer sheet (convex portion forming sheet) 2 preferably has its constituent fibers oriented in a direction parallel to the direction in which the convex portions 5 extend.
By aligning the projection 5 in parallel with the extending direction, the liquid can easily flow in the fiber alignment direction. However, in the projection, the liquid is divided by the slit 6 and moved by the slit 6 to guide the liquid to the absorber side. Has the effect of facilitating.

The convex portion 5 in the present invention has a structure in which the cross-sectional shape in the direction orthogonal to the direction in which the convex portion extends is an inverted U shape, an inverted V shape, and a Ω shape, and the lower half portion supports the upper half portion, It is preferable because the shape of the convex portion is easily maintained.

  The surface sheet in the present invention is, for example, a method of performing slit processing on the upper layer sheet, guiding the upper layer sheet between two heated concavo-convex biting rolls, providing the concavo-convex structure, and joining the lower layer sheet, or as a lower layer sheet While the heat-shrinkable non-woven fabric (for example, the non-woven fabric containing the latent crimpable fiber described above) is continuously conveyed, the upper layer sheet provided with slits by a slit forming device such as a rotary cutter is partially formed by means such as heat embossing. After the integration process is performed, a heat treatment is performed by a heating device so as to shrink in a direction perpendicular to the slit, or the heat shrinkable nonwoven fabric is subjected to the same uneven process as described above, and then the slit is formed. It can manufacture by the method of forming. As the slit forming device, in addition to a rotary cutter, a shear cutter, a laser cutter, an ultrasonic cutter, or the like can be used.

  Moreover, the surface sheet of the two-layer structure using the upper layer sheet of the non-stretchable nonwoven fabric and the stretchable web (including the nonwoven fabric), for example, extends the lower layer sheet in a direction orthogonal to the direction in which the convex portions continue. After being joined to the upper layer sheet in a state where it is in a stretched state, it is obtained by a method of releasing the stretched state of the lower layer sheet and generating a convex portion. Moreover, the surface sheet which has the lower layer sheet 3 containing the latent crimpable fiber which expressed the crimp by heat processing is the upper layer sheet 2 which formed the slit previously in the site | part which produces a convex part, and the lower layer containing a latent crimpable fiber After the sheet 3 is laminated and bonded at the predetermined bonding portion 4, the lower crimped fiber is contracted by heat shrinking by heat treatment, thereby causing the upper sheet 2 to protrude to one side. It can be obtained by forming the convex portion 5 by inflating it. Thus, when forming the convex part 5 by the heat shrink of a latent crimpable fiber, the quantity of the latent crimpable fiber contained in the lower layer sheet 3 before heat shrink is the weight of the lower layer sheet 3 before heat shrink. On the other hand, it is preferably 50% by weight or more, particularly preferably 70 to 100% by weight.

  According to the surface sheet 1 in the present embodiment, when the napkin (absorbent article) 20 is used, partial pressure is applied to the surface sheet, so that the shape of the portion 55 between the slits of the convex portion 5 is, for example, from FIG. As shown in FIG. 4, the side edge portion 62 of the slit 6 is deformed into a shape that is in close contact with or close to the lower layer sheet 3 (absorber when there is no lower layer sheet 3). Thereby, the liquid supplied (excreted) on the top sheet is smoothly transferred to the absorber 22 arranged under the top sheet 1. Moreover, as shown in FIG. 5, the liquid which flowed through the trough produced between convex parts flows into the slit 6 opened by the deformation | transformation of the convex part by pressurization, and, thereby, the liquid on a surface sheet is also an absorber. Transition smoothly.

  Thus, the surface sheet of this embodiment is excellent in the liquid permeability, and can prevent inconveniences such as stickiness due to the liquid remaining on the surface of the surface sheet. Further, according to the absorbent article using such a surface sheet, liquid such as menstrual blood or urine can be quickly transferred to the absorbent body, and inconvenience such as stickiness due to liquid remaining on the surface can be prevented. Can do.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the convex portions of the topsheet in the present invention may be discontinuous (independent convex portions) in both the longitudinal direction and the width direction of the absorbent article, or form continuous convex portions. The direction in which the convex part extends may be parallel to the longitudinal direction or the width direction of the absorbent article, and may be deformed flexibly into the curved shape and movement of the body by the slit, and the absorbent article From the viewpoint of dividing the movement of the liquid in the longitudinal direction, the liquid is preferably parallel to the longitudinal direction of the absorbent article.

The present invention is not limited to one in which all of the convex portions formed on the topsheet have slits. However, it is preferable that the convex portions having slits are distributed in a predetermined pattern within a certain region.
FIG. 6 is a view (an equivalent view of FIG. 1) showing another embodiment of the absorbent article and the top sheet of the present invention, and the top sheet 1 ′ is a convex portion extending continuously in one direction (X direction). 5 and a plurality of convex portions 5 have slits 6. It is preferable that the convex part which has a slit is disperse | distributing with the predetermined pattern in predetermined areas, such as the site | part arrange | positioned facing the excretion part of an absorbent article, for example.

Examples of absorbent articles in the present invention include sanitary napkins, panty liners, disposable diapers, incontinence pads, breast milk absorption pads, and the like.
In addition, as a constituent material of each of the absorbent body and the back sheet, those conventionally used in this type of article can be used. For example, as the absorbent body, a fiber assembly made of pulp fibers or thermoplastic fibers ( Fiber web, non-woven fabric, etc.) or a layer in which a water-absorbing polymer is held in a layered or dispersed state can be used. As the back sheet, a film of a thermoplastic resin such as polyethylene, polypropylene, polyvinyl acetate, polyester, Water-repellent spunbond nonwovens, spunbond-meltblown-spunbond multilayered nonwoven fabrics, and the like can be used.

FIG. 1 is a perspective view showing a sanitary napkin as an embodiment of the absorbent article of the present invention in a broken state, and the surface sheet of the napkin is an embodiment of the surface sheet of the absorbent article of the present invention. is there. FIG. 2 is a schematic cross-sectional view for explaining the shape and the like of the convex portions and slits of the topsheet shown in FIG. FIG. 3 is a schematic cross-sectional view showing a cross section taken along line II of the topsheet shown in FIG. FIG. 4 is a schematic cross-sectional view showing a cross section corresponding to FIG. 3 in a state where the shape of the portion between the slits of the convex portion has changed due to partial pressurization during use. FIG. 5 is a perspective view showing a state in which the shape of the convex portion is changed by partial pressurization during use. FIG. 6 is a diagram (corresponding to FIG. 1) showing another embodiment of the present invention.

Explanation of symbols

1,1 'surface sheet 2 upper layer sheet (nonwoven sheet for forming convex portions)
3 Lower layer sheet 4 Joining part 5 of upper sheet and lower layer sheet 5 Convex part 6 Slit

Claims (5)

An absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent interposed between both sheets,
The topsheet has a plurality of convex portions of the inner cavity, convex section may have a slit through the top,
An absorbent article in which at least one end of the slit reaches the lower half of the convex portion . The convex portion extends continuously in one direction of the topsheet, said slit absorbent article of claim 1 wherein extending in a direction intersecting with the one direction. The absorptive article according to claim 2 in which said convex part is constituted from a nonwoven fabric sheet, and constituent fibers of said nonwoven fabric sheet are oriented in a direction parallel to the direction in which said convex part extends. The top sheet is composed of an upper layer sheet and a lower layer sheet, and the upper layer sheet and the lower layer sheet are bonded to each other at a predetermined interval to form a plurality of joints, and the upper layer sheet is formed of the lower layer sheet. The absorptive article according to any one of claims 1 to 3 which has formed said convex part between said joined parts by contraction. It is a top sheet of an absorbent article consisting of an upper layer sheet and a lower layer sheet made of nonwoven fabric,
The upper layer sheet and the lower layer sheet are joined to each other at a predetermined interval to form a plurality of joints, and the upper layer sheet is formed with a convex portion of an internal cavity between the joints by contraction of the lower layer sheet. It is, the convex section may have a slit through the top,
The surface sheet of an absorbent article , wherein at least one end of the slit reaches the lower half of the convex portion .

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