JPH11347062A - Top sheet material for absorptive article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a top sheet material for a top sheet for absorptive article such as paper diaper, sanitary napkin, etc., which does not give wet feeling of paper diaper and generate fluffing. SOLUTION: This top sheet material for absorptive article is composed by forming an uneven part, whose protruding part tip end upper face is made to be a film-like, by thermal embossing on the surface of sheet hydrophilic- treated combined fiber nonwoven fabric. The top sheet has usually 0.2-3 mm thickness from the protrusion top upper face to the recess part backside, 0.5-30 mm<2> of area of the protrusion tip upper face, and 10-70% of the area rate of the protrusion. The wet pack volume of body fluid excreted from a human body can be more reduced compared to a cubic-formed nonwoven fabric by the material and the material is excellent in cushionablility, flexibility, permeability, a hand feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a topsheet material for absorbent articles, and more particularly to a topsheet material formed of a three-dimensionally shaped nonwoven fabric suitable for absorbent articles such as disposable diapers and sanitary napkins.

[0002]

BACKGROUND OF THE INVENTION Conventionally, flat spunbond polypropylene nonwoven fabrics and point-bond dry nonwoven fabrics have been used as nonwoven fabrics for top sheets of disposable diapers.
However, these nonwoven fabrics are not bulky, and when a disposable diaper using these nonwoven fabrics as a topsheet nonwoven fabric is used, the bodily fluid excreted from the human body moves from the topsheet of the disposable diaper to the absorber, and the bodily fluid is removed. A part of the diaper moves to the top sheet again, so-called wet back, so that a wet feeling remains, and the usability of the disposable diaper is poor. Further, since the top sheet of the disposable diaper contacts the entire surface of the human skin, the touch (flexibility) is inferior.

[0003] Air-laid nonwoven fabric of dry-type composite staple fiber and hot air through binding nonwoven fabric of card web have been used as improved products having improved usability and tactile sensation as described above. However,
Although these nonwoven fabrics are bulky and have improved tactile sensation (flexibility and elasticity), the topsheet made of these nonwoven fabrics comes into full contact with human skin, so that the above-mentioned wet feel remains. However, the use feeling of disposable diapers has not been sufficiently improved. In addition, since the surface strength of these top sheets is insufficient, fluffing due to abrasion is a problem. Furthermore, there is a disadvantage that the productivity of these nonwoven fabrics is poor.

Accordingly, the inventors of the present application have made intensive studies to reduce the contact area between human skin and the top sheet and improve the cushioning property, thereby improving the above-mentioned wet feel or feeling of use. Considering that the bonding between the fibers forming the nonwoven fabric is further strengthened to prevent the above-mentioned fuzzing, the surface of the sheet-shaped hydrophilically-treated composite nonwoven fabric prepared from the core-sheath type or the side-by-side type composite fibers is subjected to heat. An embossing process was used to form an uneven portion, and the top surface of the tip of the projecting portion was formed into a film.The resulting three-dimensionally shaped nonwoven fabric was used as a top sheet material to produce a disposable diaper.
The present inventors have found that there is no wet feeling and that fluffing can be prevented, and the present invention has been completed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems associated with the prior art as described above, and a disposable diaper capable of forming a lint-free topsheet without a wet feel of the disposable diaper. It is an object of the present invention to provide a topsheet material for a topsheet for absorbent articles such as sanitary napkins.

[0006]

SUMMARY OF THE INVENTION The top sheet material for an absorbent article according to the present invention comprises a sheet-like hydrophilically-treated composite fiber nonwoven fabric having a surface formed with irregularities by hot embossing, and a top surface portion of the projecting portion formed of a film. It is characterized by being shaped.

[0007] The top sheet material for an absorbent article usually has a thickness of 0.2 to 0.2 mm from the top surface of the top of the projection to the back of the recess.
3 mm, and the area of the top surface of the tip of the projection is 0.5 to 30 m
m ² , and the area ratio of the projections is 10 to 70%.

The above-mentioned “film formation” means that the apparent density (d _F ; g / cm ³ ) of the film-formed portion is 化 d _M ≦ d _F ≦ d _M (d _M is hot embossed). The density (g / cm ³ ) of the previous sheet-like hydrophilically-treated composite fiber nonwoven fabric) is satisfied.

[0009] In the top sheet material for absorbent articles according to the present invention, the film-formed portion has excellent water pressure resistance, and portions other than the film-formed portion have excellent liquid permeability. ADVANTAGE OF THE INVENTION The top sheet material for absorbent articles which concerns on this invention can reduce the wet-back of the bodily fluid from an absorber remarkably by excellent water pressure resistance and bulkiness. For example, when this top sheet material is used for a top sheet of a disposable diaper, the amount of bodily fluid excreted from the human body that returns to the top sheet due to wet back can be reduced, so that the disposable diaper does not feel wet.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the top sheet material for absorbent articles according to the present invention will be specifically described. In the top sheet material for an absorbent article according to the present invention, irregularities are formed by heat embossing on the surface of the sheet-like hydrophilically-treated composite fiber nonwoven fabric, and the top surface of the tip of the projection is formed into a film. FIG. 1 is a schematic perspective view for explaining a film-formed portion on the top surface of the tip of the projection of the top sheet material according to the present invention. Reference numeral 1 in the drawing denotes a film-formed portion on the top surface of the tip of the projection.

Sheet-like hydrophilically-treated composite fiber nonwoven fabric The sheet-like, hydrophilically-treated composite fiber nonwoven fabric used in the present invention is prepared from a core-sheath type or side-by-side type composite fiber comprising a high-melting component and a low-melting component. It is a hydrophilically treated product of a composite fiber nonwoven fabric. As the composite fiber nonwoven fabric, a spun bond nonwoven fabric and a melt blown nonwoven fabric are preferably used.

The above-mentioned "high melting property" means that a polymer resin composed of monomers of the same series has a high melt flow rate, and that a polymer resin composed of monomers of a different series does not. 15 ° C. or more, preferably 20
It means higher by at least 25 ° C, more preferably at least 25 ° C. Therefore, the high melting component can be called a low melting component, and the low melting component can be called a high melting component.

The spunbonded nonwoven fabric and the meltblown nonwoven fabric used in the present invention have a core composed of a sheath composed of polyolefin (i) and a core composed of polyolefin (ii) having a higher melting point than polyolefin (i) of the sheath. It is prepared from a sheath type composite fiber or a side-by-side type composite fiber composed of a polymer part composed of the polyolefin (i) and a polymer part composed of the polyolefin (ii).

[Core-sheath type conjugate fiber] The polyolefin (i) forming the sheath portion is not particularly limited, but an ethylene polymer is preferably used.

As the ethylene polymer, a homopolymer of ethylene (the production method may be either a low pressure method or a high pressure method)
Alternatively, a random copolymer of ethylene and an α-olefin such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene may be mentioned.

These ethylene polymers have a density (ASTM
D 1505) is 0.880~0.970g / cm ^3, preferably in the range of 0.900~0.950g / cm ^3,
Melt flow rate (MFR; ASTM D 1238, 190 ° C., load 2.16 kg) is 20 to 60 g / 10 min, preferably 30 to 60 g
40 g / 10 min and Mw / Mn (M
(w: weight average molecular weight, Mn: number average molecular weight) is preferably in the range of 2 to 4 from the viewpoint of spinnability. As the ethylene polymer, an ethylene homopolymer having a density, MFR and Mw / Mn within the above ranges is preferable in view of flexibility and spinnability of the obtained nonwoven fabric. Note that Mw / Mn is
It can be determined by a conventionally known method by gel permeation chromatography (GPC).

The polyolefin (ii) forming the core is not particularly limited, but a polyolefin having a higher melting point than the polyolefin (i) forming the sheath is used. The difference between the melting point of the polyolefin (ii) forming the core and the melting point of the polyolefin (i) forming the sheath is 10
It is desirable that the temperature is not less than ° C.

As the polyolefin (ii) forming the core, a propylene polymer is preferably used. As the propylene-based polymer, propylene homopolymer or propylene, ethylene, 1-butene, 1-hexene, 4-
Examples include random copolymers with α-olefins such as methyl-1-pentene and 1-octene.

These propylene / α-olefin random copolymers have an α-olefin component content of 0.5 to 5%.
It is desirably in the range of mol%. These propylene polymers have a density (ASTM D 1505) of 0.890 to
0.91 g / cm ³ , and a melt flow rate (MFR; ASTM D 1238, 230 ° C., load 2.16 kg) of 10 to 70 g / 10 minutes, preferably 30 to 60 g / 10
Min and Mw / Mn is preferably in the range of 2 to 4 from the viewpoint of spinnability.

The weight ratio ((ii) / (i)) of the polyolefin (ii) forming the core of the composite fiber to the polyolefin (i) forming the sheath is 5/95 to 50/50, preferably 5/95 to 40/60, more preferably 5/9
It is desirable to be in the range of 5-20 / 80.

The weight ratio of the polyolefin (ii) to the polyolefin (i) forming the sheath ((ii) / (i))
If the ratio is too small below 5/95, the strength of the conjugate fiber may be insufficient, while if it exceeds 50/50, the conjugate fiber may be inferior in flexibility.

The spunbonded nonwoven fabric prepared from the core-sheath type conjugate fiber whose sheath portion is formed from the above-mentioned ethylene-based polymer has most or all of the surface of the conjugate fiber constituting the nonwoven fabric made of the above-mentioned ethylene-based polymer. Therefore, it is excellent in flexibility as compared with a conventional nonwoven fabric made of polypropylene. Further, when the conjugate fiber constituting the nonwoven fabric is a crimped fiber, the flexibility is further improved.

As such a composite fiber, for example,
(1) a coaxial core-sheath composite fiber composed of a sheath formed of an ethylene-based polymer and a core formed of a propylene-based polymer, (2) a sheath formed of an ethylene-based polymer And an eccentric core-sheath type composite fiber comprising a propylene-based polymer and a core formed of a propylene-based polymer. Among them, the eccentric core-sheath composite fiber of (2) is a crimped fiber.

FIGS. 2 and 3 show schematic cross sections of the core-sheath composite fiber. FIG. 2 shows a schematic cross section of a concentric core-sheath composite fiber. FIG. 3 shows a schematic cross section of an eccentric core-sheath conjugate fiber. As shown in FIG. 3A, a core-sheath conjugate fiber whose core is not exposed on the fiber surface is used. A core-sheath type composite fiber having a core portion partially exposed on the fiber surface as shown in FIG. 3B can also be used. In addition, the code | symbol 2 in a figure shows a core part, and the code | symbol 3 shows a sheath part.

Further, in the present invention, if necessary, the polyolefin (i) and / or the polyolefin (ii)
Other polymers, coloring materials, heat stabilizers, nucleating agents, slip agents and the like can be blended as long as the object of the present invention is not impaired.

[Side-by-side conjugate fiber] The side-by-side conjugate fiber used in the present invention comprises the above-mentioned polymer portion composed of polyolefin (i) and the polymer portion composed of polyolefin (ii). The content of the low-melting polyolefin (i) is usually 20 to 80% by weight, preferably 40 to 60% by weight, and the content of the polyolefin (ii) having a higher melting point than the polyolefin (i) is usually 20 to 80% by weight. , Preferably 40 to 60% by weight.

FIG. 4 is a schematic sectional view of a side-by-side type conjugate fiber. In the drawings, reference numeral 4 denotes a polymer portion composed of a high melting point component such as a propylene polymer, and reference numeral 5 denotes a polymer portion composed of a low melting point component such as an ethylene polymer.

In the present invention, if necessary, the polyolefin (i) and / or the polyolefin (ii)
Other polymers, coloring materials, heat stabilizers, nucleating agents, slip agents and the like can be blended as long as the object of the present invention is not impaired.

[Preparation of Spunbonded Nonwoven Fabric] The spunbonded nonwoven fabric comprising the above-mentioned conjugate fiber can be prepared by a conventionally known method. For example, a polyolefin (i) forming a sheath portion and a polyolefin forming a core portion ( By preparing a web simultaneously with melt-spinning by ii) by the composite spunbonding method and needle-punching or thermally fusing the web, a spunbonded nonwoven fabric made of a core-sheath type composite fiber can be prepared. At this time, the spun fibers are drawn and stretched using an air flow, a water flow, or a centrifugal force, and the drawn fibers are received by a conveyor or the like to form a sheet-like web.

The fiber diameter of the fibers forming the spunbonded nonwoven fabric is usually about 10 to 40 μm, preferably about 15 to 25 μm. The basis weight of the spunbonded nonwoven fabric used in the present invention is usually 10 to 30 g / m ² , preferably 15 to 25 g / m ² .

[Preparation of Meltblown Nonwoven Fabric] The meltblown nonwoven fabric composed of the above-mentioned conjugate fiber can be prepared by a conventionally known method. For example, a polyolefin (i) forming a sheath portion and a polyolefin (ii) forming a core portion. Is melt-extruded, and the fiber having a core-sheath structure spun from a melt-blow spinneret is blow-spun as an ultrafine fiber stream by a high-temperature, high-speed gas, formed into an ultrafine fiber web by a collecting device, and heat-fused if necessary. Thereby, a melt-blown nonwoven fabric composed of the core-sheath type conjugate fiber can be prepared.

The fiber diameter of the fibers forming the melt blown nonwoven fabric is usually about 5 to 30 μm, preferably about 10 to 20 μm. The basis weight of the melt blown nonwoven fabric used in the present invention is usually 10 to 30 g / m ² , preferably 15 to 25 g / m ² .

[Hydrophilic treatment] The hydrophilically treated sheet-shaped composite fiber non-woven fabric used in the present invention is obtained by adding a hydrophilic agent such as a 0.1 to 20% by weight aqueous solution of a surfactant to the non-woven fabric obtained as described above. Can be obtained by applying and drying to make the nonwoven fabric hydrophilic.

Examples of such surfactants include nonionic surfactants such as higher alcohol ethylene oxide adducts, higher alcohol propylene oxide adducts, polyethylene glycol fatty acid esters, polyhydric alcohol fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters. Agents; anionic surfactants such as aliphatic sulfonates, higher alcohol sulfates, higher alcohol ethylene oxide adduct sulfates, higher alcohol phosphates, higher alcohol ethylene oxide adduct phosphates; A cationic surfactant such as a quaternary ammonium salt type cationic surfactant;
Betaine-type amphoteric surfactants are exemplified. Among them, nonionic surfactants are preferable in terms of safety and stability over time of hydrophilicity. In particular, it is preferable to combine two or more nonionic surfactants.

The hydrophilic treatment with a hydrophilic agent can be performed by a conventionally known coating method, for example, the following coating method. (1) Roll coating method using a gravure printing machine (2) Foam coating method (3) Spray coating method (4) Immersion method Among the above (1) to (4), the coating method (1) is preferable.

The hydrophilically treated sheet-shaped nonwoven fabric obtained as described above has a basis weight of usually 10 to 50 g / m ² , preferably 15 to 30 g / m ² , and a thickness of usually 50 to 50 g / m ² measured by an optical microscope. 300 μm, preferably 100-2
00 μm.

Hot Embossing The topsheet material for absorbent articles according to the present invention is formed by subjecting the sheet-like hydrophilically-treated composite fiber nonwoven fabric obtained as described above to hot embossing to form irregularities, Is obtained by forming the top surface portion of the film into a film. The portion other than the top surface of the tip of the convex portion formed on the hydrophilically-treated composite nonwoven fabric is a nonwoven fabric that is not formed into a film at all.

In the present specification, “film formation” means the apparent density (d) of a film-formed portion unless otherwise specified.
_F;. G / cm ³⁾ _{is, 1 / 2d M ≦ d F} ≦ d M (d M , the density of the sheet-like hydrophilic treatment composite fiber nonwoven fabric before being processed hot embossing (g / cm ³⁾ is a) of It means that the relationship is satisfied.

The film-formed portion has a texture of a nonwoven fabric, and the texture is intermediate between the texture of the film and the texture of the nonwoven fabric. This apparent density (d _F )
Is calculated from the following formula using the thickness of the film-formed portion measured by observation with a cross-sectional magnification microscope.

[0040] In ^{_{d F (g / cm 3)}} = NW A (g / 10 4 cm 2) / T F (cm) This equation, NW _A is three-dimensional shaped been the entire nonwoven fabric basis weight (g / 10 ⁴ cm ² ), and T _F is the thickness (cm) of the film-formed portion.

The hot embossing process is an embossing device (I) comprising a combination of one embossing roll and one smooth soft roll, or an embossing device comprising a male and female engagement type embossing roll. It is desirable to use an embossing apparatus (II) that combines an embossing roll with a high peak (projection) and an embossing roll with a low peak (projection) that matches this embossing roll. In the embossing device (I), an embossing roll is used as a hot roll, and a smooth soft roll is used as a cooling roll. In the embossing device (II), an embossed roll having a high peak is used as a hot roll, and an embossed roll having a low peak is used as a cooling roll. When these two embossing rolls are engaged with each other, a gap is formed, so that it is possible to form only the hydrophilically-treated composite fiber non-woven fabric portion that comes into contact with the tip end surface of the embossing roll having a high peak.

Examples of the embossing roll include a steel roll. Examples of the smooth soft roll include a soft rubber roll such as a soft silicone rubber roll.

The embossed pattern formed on the sheet-like hydrophilically treated conjugate fiber nonwoven fabric may be formed of a circle having a diameter of 0.8 to 6 mm or a square having a side of 0.2 to 5 mm. Preferably, when the shape is a circle, the pitch between adjacent protrusions is preferably 1.2 to 3 times the diameter of the circle, and the height of the protrusion is preferably 0.5 to 2 times the diameter of the circle. When the shape is a square, the pitch between adjacent protrusions is 1.2 to 3 times the length of one side of the square, and the height of the protrusion is 0.5 to 2 times the length of one side of the square. Preferably, there is.

The diameter of the embossing roll is usually 200 to 10
00 mm, preferably 300 to 800 mm, and the diameter of the smooth soft roll is usually 200 to 1000 mm, preferably 300 to 800 mm.

The surface temperature of the embossing roll in the hot embossing is set at a temperature at which the low-melting component portion constituting the composite fiber does not melt, and at a temperature at which the high-melting component portion melts. Since the embossing roll having a low peak constituting the embossing device (II) is used as a cooling roll, its surface temperature is usually room temperature.

The linear pressure of the embossing roll in hot embossing is 5 to 150 kg / cm, preferably 30 to 150 kg / cm.
７０70 kg / cm. Since the sheet-like hydrophilically-treated composite fiber nonwoven fabric used in the present invention is composed of a composite fiber composed of a portion made of a high-melting component and a low-melting portion, the three-dimensional shapeability by hot embossing and its shaping are obtained. Excellent shape retention.

Top Sheet Material The top sheet material for an absorbent article according to the present invention, which is obtained by the hot embossing as described above, has a thickness (from the top surface of the convex portion formed by the hot embossing process to the back surface of the concave portion). The thickness of the three-dimensionally shaped nonwoven fabric) is 0.2 to ³ mm, preferably 0.5 to 1.5 mm, and the area of the top surface of the convex tip is 0.5 to 30 mm ² , preferably 1 to 5 mm ² , The area ratio of the projections is 10 to 70%, preferably 30 to 5
Desirably, it is 0%. The thickness is a value measured using an optical microscope.

In the absorbent article using the top sheet material for an absorbent article according to the present invention as a top sheet, the top sheet material is disposed such that the surface of the top sheet material having the film-formed portion is in contact with human skin. When this arrangement is reversed, the absorption speed of the bodily fluid decreases, and the wet-back amount of the bodily fluid from the absorber increases.

[0049]

The topsheet material for an absorbent article according to the present invention is a three-dimensionally shaped nonwoven fabric whose surface is formed unevenly, and the top surface portion of the projection is formed into a film. Since the shaped portion has the texture of a nonwoven fabric, the amount or rate of wetback of bodily fluids excreted from the human body can be further reduced as compared to a nonwoven fabric simply shaped in three dimensions. Further, the topsheet material for an absorbent article according to the present invention is excellent in cushioning property, flexibility, air permeability and feel to the touch.

Therefore, the top sheet material for absorbent articles according to the present invention is suitable for absorbent articles such as disposable diapers and sanitary napkins. The absorbent article using this top sheet material is excreted from the human body. There is no wet feeling due to the wet back of the bodily fluid, and the usability is good,
The fluff of the top sheet material can be prevented. When this top sheet material for an absorbent article having excellent air permeability is used for a top sheet such as a disposable diaper or a sanitary napkin, rough skin and stuffiness can be prevented.

[0051]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

The embossing apparatus used in Examples and the like, which comprises the sheet-form composite fiber nonwoven fabric, the coating solution for the hydrophilic agent, and the embossing roll of the male and female engagement type is as follows. [Sheet-shaped composite fiber nonwoven fabric] Spunbond nonwoven fabric (S
PB) This nonwoven fabric was manufactured as follows. That is, the ethylene component content is 5 mol%, and the density (ASTM D 1505) is 0.1%.
91 g / cm ³ , MFR (ASTM D 1238, 230 ° C, load 2.
16 kg) of 50 g / 10 min propylene / ethylene random copolymer, 1-butene content of 4 mol%, density (ASTM D
1505) is 0.948 g / cm ³ , MFR (ASTM D 123
8,190 ° C, load 2.16kg) is 30g / 10min.
The core is a propylene / ethylene random copolymer and the sheath is an ethylene / 1-butene random copolymer (core: sheath) formed by performing composite melt spinning using 1-butene random copolymer. Parts of the core-sheath type composite fibers having a weight ratio of 5: 5) are deposited on the collecting surface, and the basis weight is 23 g / m2.
A spunbonded nonwoven fabric of No. ² (fineness of constituent fibers: 3 denier) was produced. [Hydrophilic agent coating solution] 1% by weight of a surfactant (trade name: Pepol ^™ AS-054C) manufactured by Toho Chemical Industry Co., Ltd. and a surfactant (Pronal ^™ 502) manufactured by Toho Chemical Industry Co., Ltd.
F) A hydrophilic agent coating liquid consisting of 1% by weight and 98% by weight of water. [Embossing Apparatus Consisting of Male and Female Interlocking Embossing Rolls] In this embossing apparatus, as shown in FIG. A male embossing roll 7 is arranged and arranged in parallel in the longitudinal direction of the roll at a predetermined interval, and a female embossing roll (not shown) that meshes with the male embossing roll 7 is provided. . The height of the convex portions 6 of the male embossing roll 7 is 1 mm as shown in FIG. 5B, and the pitch of the adjacent convex portions 6 is 2.828 mm.

The absorption time, the wet back rate, and the surface friction coefficient of the physiological saline solution performed in Examples and the like were measured as follows. (1) Method for measuring absorption time and wetback rate of physiological saline The top sheet of a commercially available absorbent article was peeled off, and the three-dimensionally shaped nonwoven fabric produced this time was laid as a top sheet at the place where the top sheet was peeled off. 5% 8% saline
Is dropped, and the absorption time of the physiological saline is measured. After dropping, leave for 30 seconds and again 5 ml of 0.8% concentration physiological saline.
The solution is dropped, and the absorption time of the physiological saline (time until the water completely drains from the top sheet to the absorber) is measured.

Then, after standing for another 1 minute, 10 filter papers are stacked on the three-dimensionally shaped nonwoven fabric (top sheet), and a weight of 5 kg is further placed thereon, and the amount of water returned from the absorber to the filter paper is returned. Is weighed to obtain a return amount (wet back amount). (2) Surface friction coefficient For the non-woven fabric before hot embossing, using a friction tester (KES-SE type, manufactured by Kato Tech Co., Ltd.)
At 23 ° C., MIU (mean static friction coefficient) and MMD (fluctuation of friction coefficient) in the MD direction (longitudinal direction) and CD direction (lateral direction) of the sample surface were measured. The smaller the MIU (mean static friction coefficient) value, the better the surface smoothness.

[0055]

Example 1 On one surface of the spunbonded nonwoven fabric (SPB), the hydrophilic agent coating solution was applied using a gravure coater (roll diameter: 200 mm, roll mesh: 150 #).
It was applied at a coating speed of 10 m / min and dried at 85 ° C. for 1 minute to obtain a hydrophilically treated spunbonded nonwoven fabric (SPB). The hydrophilic treatment of the resulting spunbonded nonwoven fabric (SPB), hydrophilic agent amount for the nonwoven fabric 1 m ² (solid content) is 0.
The weight was 5 g / m ² , the basis weight was 3.5 g / m ² , and the thickness (measured with an optical microscope; the same applies hereinafter) was 152 μm.

Next, the spunbonded nonwoven fabric (SP
Using the above embossing device for the hydrophilically treated product of B),
Embossing was performed under the following conditions to prepare a three-dimensionally shaped nonwoven fabric having a thickness of 2 mm.

<Embossing Conditions> Surface temperature of embossing roll: 120 ° C. Linear pressure: 70 kg / cm Processing speed: 20 m / min Then, the top sheet (hydrophilic product) of a commercially available children's diaper (M size) was peeled off. Instead of this top sheet, the three-dimensionally formed nonwoven fabric obtained as described above is used as the topsheet, and the topsheet 8 / absorber 9 / backsheet 10 layer made of the three-dimensionally formed nonwoven fabric as shown in FIG. A disposable diaper having the configuration was produced.

With respect to this disposable diaper, the absorption time and the wet-back rate of the physiological saline were measured according to the above-mentioned methods. Table 1 shows the results.

[0059]

Reference Example 1 The procedure of Example 1 was repeated, except that a disposable diaper was manufactured with the film-formed portion 1 of the top sheet 8 facing the absorber.

With respect to this disposable diaper, the absorption time and the wet-back rate of the physiological saline were measured according to the above-mentioned methods. Table 1 shows the results.

[0061]

Comparative Example 1 A disposable diaper was prepared in the same manner as in Example 1 except that the hydrophilically treated spunbonded nonwoven fabric (SPB) of Example 1 was used without performing hot embossing. did.

With respect to this disposable diaper, the absorption time and the wet-back rate of the physiological saline were measured according to the above-mentioned methods. Table 1 shows the results.

[0063]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a schematic perspective view for explaining a film-formed portion on a top surface of a front end of a convex portion of a top sheet material according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a coaxial core-sheath composite fiber.

FIGS. 3A and 3B are schematic cross-sectional views showing eccentric core-sheath composite fibers.

FIG. 4 is a schematic sectional view showing a side-by-side type conjugate fiber.

FIG. 5A is a schematic partial perspective view of a male embossing roll constituting an embossing device used in an example according to the present invention, and FIG. It is a partial sectional view for explaining the shape of the convex part formed in the male type embossing roll surface.

FIG. 6 is a partial cross-sectional view showing a layer configuration of a disposable diaper obtained in an example according to the present invention.

[Explanation of symbols]

1 ······························· High-melting point component such as propylene-based polymer Polymer part 5 ····· Polymer part composed of low melting point component such as ethylene polymer 6 ································· Male embossing roll 8 ···・ ・ ・ Top sheet 9 ・ ・ ・ ・ ・ Absorber 10 ・ ・ ・ Back sheet

Continuing on the front page (72) Inventor Haruki Nagaoka, Asahi-cho, Yokkaichi-shi, Mie Prefecture, Mitsui Chemicals Co., Ltd.

Claims (3)

[Claims] An absorbent article characterized in that an uneven portion is formed on the surface of a sheet-like hydrophilically-treated composite fiber nonwoven fabric by hot embossing, and the top surface of the tip of the convex portion is formed into a film. Top sheet material. 2. The thickness from the top surface of the projection to the back surface of the depression is 0.2 to 3 mm, the area of the top surface of the projection is 0.5 to 30 mm ² , and the area ratio of the projection is 10-70
%. The top sheet material for an absorbent article according to claim 1, wherein 3. An apparent density (d _F ; g / cm ³ ) of the film-formed portion is ｄd _M ≦ d _F ≦ d _M (d _M is a sheet-like hydrophilically treated composite before hot embossing. The top sheet material for an absorbent article according to claim 1, wherein the density (g / cm ³ ) of the fibrous nonwoven fabric is satisfied.