JP4007685B2 - Top sheet material for absorbent articles - Google Patents

Description

【図面の簡単な説明】
【図１】図１は、本発明に係るトップシート材の凸部の先端上面におけるフィルム状化部分を説明するための模式斜視図である。
【図２】図２は、同芯の芯鞘型複合繊維を示す模式断面図である。
【図３】図３の（Ａ）と（Ｂ）は、偏芯の芯鞘型複合繊維を示す模式断面図である。
【図４】図４は、サイドバイサイド型複合繊維を示す模式断面図である。
【図５】図５の（Ａ）は、本発明に係る実施例で用いたエンボス加工装置を構成している雄型エンボスロールの模式部分斜視図であり、図５の（Ｂ）は、該雄型エンボスロール表面に形成されている凸部の形状を説明するための部分断面図である。
【図６】図６は、本発明に係る実施例で得られた紙おむつの層構成を示す部分断面図である。
【符号の説明】
１ ・・・・・ トップシート材の凸部先端上面のフィルム状化部分
２ ・・・・・ 芯部
３ ・・・・・ 鞘部
４ ・・・・・ 高融点成分たとえばプロピレン系重合体からなる重合体部
５ ・・・・・ 低融点成分たとえばエチレン系重合体からなる重合体部
６ ・・・・・ エンボスロールにおける凸部（突起）
７ ・・・・・ 雄型エンボスロール
８ ・・・・・ トップシート
９ ・・・・・ 吸収体
１０ ・・・ バックシート[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a top sheet material for absorbent articles, and more particularly to a top sheet material made of a three-dimensionally shaped nonwoven fabric suitable for absorbent articles such as disposable diapers and sanitary napkins.
[0002]
TECHNICAL 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 using a paper diaper that uses these nonwoven fabrics as the nonwoven fabric for the top sheet, the body fluid excreted from the human body moves from the top sheet of the paper diaper to the absorber, and the body fluid Due to the so-called wet back in which a part of the paper moves to the top sheet again, the wet feeling remains and the usability of the disposable diaper is poor. Moreover, since the top sheet of a paper diaper contacts the human skin on the entire surface, the tactile sensation (flexibility) is inferior.
[0003]
Air-laid nonwoven fabrics of dry composite staple fibers and hot air-through binding nonwoven fabrics of card webs have come to be used as improvements in the feeling of use and touch as described above. However, these nonwoven fabrics are bulky and have improved tactile feel (flexibility, elasticity), but the top sheet made of these nonwoven fabrics is in contact with the human skin over the entire surface. However, the usability of disposable diapers has not been improved sufficiently. In addition, since the surface strength of these top sheets is insufficient, fuzz due to wear is a problem. Furthermore, there is a drawback that the productivity of these nonwoven fabrics is poor.
[0004]
Therefore, the inventors of the present application have studied earnestly, reducing the contact area between the human skin and the top sheet, improving the cushioning property, improving the above-mentioned wet tactile sensation or feeling of use, and further adding a nonwoven fabric. The surface of the sheet-like hydrophilic processed composite fiber nonwoven fabric prepared from the core-sheath type or side-by-side type composite fiber is considered by heat embossing in consideration of strengthening the bond between the formed fibers and preventing the above-mentioned fuzz. Forming irregularities, forming a film on the upper surface of the tip of this projection, and making a paper diaper using the resulting three-dimensionally shaped nonwoven fabric as a top sheet material, found that there is no wet feeling as described above and fuzzing can be prevented. The present invention has been completed.
[0005]
OBJECT OF THE INVENTION
The present invention is intended to solve the problems associated with the prior art as described above, such as a paper diaper, a sanitary napkin, and the like that can form a top sheet that does not have a wet feel of a paper diaper and has no fluff. It aims at providing the top sheet material for top sheets for absorbent articles.
[0006]
SUMMARY OF THE INVENTION
The top sheet material for absorbent articles according to the present invention has a concavo-convex portion formed by heat embossing on the surface of the sheet-like hydrophilic treated composite fiber nonwoven fabric, and the top surface of the tip of the bulge is formed into a film. It is characterized by.
[0007]
The top sheet material for absorbent articles usually has a thickness of 0.2 to 3 mm from the top surface of the convex portion to the back surface of the concave portion, and an area of the top surface of the convex portion of 0.5 to 30 mm.²The area ratio of the convex portions is 10 to 70%.
[0008]
The above-mentioned “filming” means an apparent density (d_FG / cm^Three)But,
1 / 2d_M≤ d_F ≤ d_M
(D_MIs the density (g / cm) of the sheet-like hydrophilic treated composite fiber nonwoven fabric before hot embossing.^Three). ) Is satisfied.
[0009]
Of the top sheet material for absorbent articles according to the present invention, the film-like portion is excellent in water pressure resistance, and the portions other than the film-like portion are excellent in liquid permeability. The top sheet material for absorbent articles according to the present invention can drastically reduce body fluid wetback from the absorbent body due to excellent water pressure resistance and bulkiness. For example, when this top sheet material is used for a top sheet of a paper diaper, the amount of bodily fluid excreted from the human body back to the top sheet due to wet back can be reduced, so that there is no wet feeling of the paper diaper.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the top sheet material for absorbent articles according to the present invention will be specifically described. As for the top sheet material for absorbent articles which concerns on this invention, the uneven | corrugated | grooved part is formed in the surface of the sheet-like hydrophilic treatment composite fiber nonwoven fabric by hot embossing, and the upper surface part of the front-end | tip of this convex part is film-like. FIG. 1 is a schematic perspective view for explaining a film-like portion on the top surface of the top of the convex portion of the top sheet material according to the present invention. The code | symbol 1 in a figure shows the film-formation part of the front end upper surface of a convex part.
[0011]
Sheet-like hydrophilic treated composite fiber nonwoven fabric
The sheet-like hydrophilic processed composite fiber nonwoven fabric used in the present invention is a hydrophilic processed product of a composite fiber nonwoven fabric prepared from a core-sheath type or side-by-side type composite fiber composed of a high melt component part and a low melt component part. As the composite fiber nonwoven fabric, a spunbond nonwoven fabric and a melt blown nonwoven fabric are preferably used.
[0012]
The above-mentioned “high meltability” means that a polymer resin made of the same series of monomers has a high melt flow rate, while a polymer resin made of a different series of monomers has a melting point of It means that the difference is 15 ° C. or higher, preferably 20 ° C. or higher, more preferably 25 ° C. or higher. Therefore, the high melting component part can be referred to as a low melting component part, and the low melting component part can be referred to as a high melting component part.
[0013]
The spunbond nonwoven fabric and the meltblown nonwoven fabric used in the present invention are a core-sheath type composite comprising a sheath part made of polyolefin (i) and a core part made of polyolefin (ii) having a melting point higher than that of polyolefin (i) of the sheath part. It is prepared from a fiber or a side-by-side type composite fiber composed of a polymer part made of the polyolefin (i) and a polymer part made of the polyolefin (ii).
[0014]
[Core-sheath type composite fiber]
The polyolefin (i) forming the sheath is not particularly limited, but an ethylene polymer is preferably used.
[0015]
As the ethylene polymer, a homopolymer of ethylene (the production method may be either a low pressure method or a high pressure method) or ethylene and propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1- And a random copolymer with an α-olefin such as octene.
[0016]
These ethylene polymers have a density (ASTM D 1505) of 0.880 to 0.970 g / cm.^Three , Preferably 0.900 to 0.950 g / cm^Three The melt flow rate (MFR; ASTM D 1238, 190 ° C., load 2.16 kg) is in the range of 20 to 60 g / 10 minutes, preferably 30 to 40 g / 10 minutes, and Mw / Mn (Mw : 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 from the viewpoint of flexibility and spinnability of the resulting nonwoven fabric. Mw / Mn can be determined by a conventionally known method by gel permeation chromatography (GPC).
[0017]
Although there is no restriction | limiting in particular as polyolefin (ii) which forms a core part, Polyolefin which has melting | fusing point higher than polyolefin (i) which forms a sheath part is used. It is desirable that the difference between the melting point of the polyolefin (ii) forming the core part and the melting point of the polyolefin (i) forming the sheath part is 10 ° C. or more.
[0018]
As polyolefin (ii) which forms a core part, a propylene polymer is preferably used.
Examples of the propylene polymer include a propylene homopolymer or a random copolymer of propylene and an α-olefin such as ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. It is done.
[0019]
These propylene / α-olefin random copolymers preferably have an α-olefin component content in the range of 0.5 to 5 mol%.
These propylene polymers have a density (ASTM D 1505) of 0.890 to 0.91 g / cm.^Three The melt flow rate (MFR; ASTM D 1238, 230 ° C., load 2.16 kg) is in the range of 10 to 70 g / 10 min, preferably 30 to 60 g / 10 min, and Mw / Mn Is preferably in the range of 2 to 4 from the viewpoint of spinnability.
[0020]
The weight ratio ((ii) / (i)) of polyolefin (ii) forming the core of the composite fiber and polyolefin (i) forming the sheath is 5/95 to 50/50, preferably 5/95. It is desirable to be in the range of ˜40 / 60, more preferably in the range of 5/95 to 20/80.
[0021]
When the weight ratio ((ii) / (i)) between the polyolefin (ii) and the polyolefin (i) forming the sheath part is too small below 5/95, the strength of the composite fiber becomes insufficient. On the other hand, if it exceeds 50/50 and becomes too large, the composite fiber may be inferior in flexibility.
[0022]
The spunbonded non-woven fabric prepared from the core-sheath type composite fiber having the sheath formed from the above-mentioned ethylene-based polymer is because most or all of the composite fiber surface constituting the non-woven fabric is composed of the above-described ethylene-based polymer. Excellent flexibility compared to conventional non-woven fabric made of polypropylene. Moreover, it is further excellent in a softness | flexibility that the composite fiber which comprises a nonwoven fabric is a crimp fiber.
[0023]
Examples of such composite fibers include (1) a concentric core-sheath type composite fiber comprising a sheath part formed from an ethylene polymer and a core part formed from a propylene polymer, and (2) ethylene. There is an eccentric core-sheath type composite fiber composed of a sheath part made of a polymer and a core part made of a propylene polymer. Of these, the eccentric core-sheath type composite fiber (2) is a crimped fiber.
[0024]
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 type composite fiber, and the core-sheath type composite fiber whose core part is not exposed on the fiber surface as shown in FIG. 3A is used. Moreover, as shown in FIG. 3B, a core-sheath type composite fiber in which the core part is partially exposed on the fiber surface 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.
[0025]
Furthermore, in the present invention, other polymers, colorants, heat stabilizers, nucleating agents, slipping agents, etc. are added to the polyolefin (i) and / or the polyolefin (ii) as necessary, as long as the object of the present invention is not impaired. Can be blended.
[0026]
[Side-by-side type composite fiber]
The side-by-side type composite fiber used in the present invention is composed of the polymer part made of the polyolefin (i) and the polymer part made of the polyolefin (ii). The content of polyolefin (i) having a low melting point is usually 20 to 80% by weight, preferably 40 to 60% by weight, and the content of polyolefin (ii) having a higher melting point than polyolefin (i) is usually 20 to 80% by weight. It is preferably 40 to 60% by weight.
[0027]
FIG. 4 shows a schematic cross-sectional view of a side-by-side type composite fiber. In the figure, reference numeral 4 denotes a polymer part made of a high melting point component such as a propylene polymer, and reference numeral 5 denotes a polymer part made of a low melting point component such as an ethylene polymer.
[0028]
Furthermore, in the present invention, other polymers, colorants, heat stabilizers, nucleating agents, slipping agents, etc. are added to the polyolefin (i) and / or the polyolefin (ii) as necessary, as long as the object of the present invention is not impaired. Can be blended.
[0029]
[Preparation of spunbond nonwoven fabric]
The spunbond nonwoven fabric composed of the above-mentioned composite fibers can be prepared by a conventionally known method. For example, a polyolefin (i) that forms a sheath part and a polyolefin (ii) that forms a core part are melt-spun by a composite spunbond method. At the same time, a spunbonded nonwoven fabric composed of core-sheath composite fibers can be prepared by making a web and needle punching or heat-sealing the web. At that time, the spun fiber is drawn and drawn using an air flow, a water flow, or centrifugal force, and the drawn fiber is received by a conveyor or the like to form a sheet-like web.
[0030]
The fiber diameter of the fibers forming this spunbonded nonwoven fabric is usually about 10 to 40 μm, preferably about 15 to 25 μm.
The basis weight of the spunbond nonwoven fabric used in the present invention is usually 10 to 30 g / m.², Preferably 15-25 g / m²It is.
[0031]
[Preparation of meltblown nonwoven fabric]
The melt blown nonwoven fabric composed of the above-described composite fiber can be prepared by a conventionally known method. For example, a polyolefin (i) that forms a sheath part and a polyolefin (ii) that forms a core part are melt-extruded and a melt blown spinneret is used. From the core-sheath composite fiber, the spun core-sheathed fiber is blow-spun as an ultrafine fiber stream with a high-temperature and high-speed gas, is made into an ultrafine fiber web with a collection device, and is heat-sealed as necessary. A meltblown nonwoven fabric can be prepared.
[0032]
The fiber diameter of the fibers forming this 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 15-25 g / m²It is.
[0033]
[Hydrophilic treatment]
The hydrophilic treatment product of the sheet-like composite fiber nonwoven fabric used in the present invention is a nonwoven fabric obtained by applying a hydrophilic agent, for example, an aqueous surfactant solution having a concentration of 0.1 to 20% by weight to the nonwoven fabric obtained as described above, and drying it. Can be obtained by hydrophilizing.
[0034]
As such a surfactant,
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, sorbitan fatty acid esters;
Anionic surfactants such as aliphatic sulfonates, higher alcohol sulfates, higher alcohol ethylene oxide adduct sulfates, higher alcohol phosphates, higher alcohol ethylene oxide adducts;
Cationic surfactants such as quaternary ammonium salt type cationic surfactants;
Examples include betaine-type amphoteric surfactants. Among these, nonionic surfactants are preferable in terms of safety and hydrophilic stability over time. In particular, it is preferable to combine two or more nonionic surfactants.
[0035]
The hydrophilic treatment with the hydrophilic agent can be performed by a conventionally known coating method, for example, the following coating method.
(1) Roll coating by 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.
[0036]
The hydrophilic processed product of the sheet-like nonwoven fabric obtained as described above has a basis weight of usually 10 to 50 g / m.², Preferably 15-30 g / m²The thickness measured with an optical microscope is usually 50 to 300 μm, preferably 100 to 200 μm.
[0037]
Heat embossing
The top sheet material for absorbent articles according to the present invention is formed by embossing the sheet-like hydrophilic treated composite fiber nonwoven fabric obtained as described above to form a concavo-convex portion, and the top surface portion of the tip of the convex portion is a film. Obtained by forming. Portions other than the top end portion of the convex portion formed on the hydrophilic treated composite fiber nonwoven fabric are nonwoven fabrics that are not formed into a film at all.
[0038]
In this specification, “film-like” means the apparent density (d of the film-like part (d) unless otherwise specified._FG / cm^Three)But,
1 / 2d_M≤ d_F ≤ d_M
(D_MIs the density (g / cm) of the sheet-like hydrophilic treated composite fiber nonwoven fabric before hot embossing.^Three). ) Is satisfied.
[0039]
The film-like portion has a nonwoven fabric texture, which is intermediate between the film texture and the nonwoven fabric texture.
This apparent density (d_F) Is calculated from the following equation using the thickness of the film-like portion measured by observation with a cross-sectional magnification microscope.
[0040]
d_F(g / cm^Three) = NW_A(g / 10^Fourcm²) / T_F(cm)
In this equation, NW_AIs the basis weight of the three-dimensionally shaped nonwoven fabric (g / 10^Fourcm²) And T_FIs the thickness (cm) of the film-like part.
[0041]
The hot embossing is an embossing device (I) formed by combining one embossing roll and one smooth soft roll, or an embossing device comprising a male and female embossing type embossing roll, It is desirable to carry out using an embossing apparatus (II) comprising a combination of an embossing roll having a high projection and a low embossing roll having a crest (projection) matching the embossing roll. In the embossing apparatus (I), an embossing roll is used as a heat roll, and a smooth soft roll is used as a cooling roll. In the embossing apparatus (II), a high embossing roll is used as a heat roll, and a low embossing roll 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 hydrophilic treated composite fiber nonwoven fabric portion in contact with the top surface of the crest of the high embossing roll.
[0042]
As an embossing roll, a steel roll etc. are mentioned, for example. Examples of the smooth soft roll include a soft rubber roll such as a soft silicone rubber roll.
[0043]
The embossed handle formed on the sheet-like hydrophilic treated composite fiber nonwoven fabric is preferably formed by a protrusion having a circle shape with a diameter of 0.8 to 6 mm or a square shape with a side of 0.2 to 5 mm. 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 protrusions 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.
[0044]
The embossing roll has a diameter of usually 200 to 1000 mm, preferably 300 to 800 mm, and the smooth soft roll has a diameter of usually 200 to 1000 mm, preferably 300 to 800 mm.
[0045]
The surface temperature of the embossing roll in the hot embossing is set to a temperature at which the low-melting component part constituting the composite fiber does not melt and a temperature at which the high-melting component part melts. Since the embossing roll with a low peak constituting the embossing apparatus (II) is used as a cooling roll, the surface temperature is usually room temperature.
[0046]
Moreover, the linear pressure of the embossing roll in hot embossing is 5-150 kg / cm, Preferably it is 30-70 kg / cm.
Since the sheet-like hydrophilic treated composite fiber nonwoven fabric used in the present invention is composed of a composite fiber composed of a part consisting of a high melt component and a low melt part, the three-dimensional formability by heat embossing and the shape thereof are formed. Excellent shape retention.
[0047]
Top sheet material
The top sheet material for absorbent articles according to the present invention, which is obtained by the heat embossing as described above, has a thickness from the top surface of the convex portion formed by hot embossing to the back surface of the concave portion (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 1-5mm²It is desirable that the area ratio of the convex portions is 10 to 70%, preferably 30 to 50%. The thickness is a value measured using an optical microscope.
[0048]
In the absorbent article using the top sheet material for absorbent articles according to the present invention for the top sheet, the surface of the top sheet material having the film-like portion is disposed so as to be in contact with human skin. If this arrangement is reversed, the absorption speed of the body fluid is slowed down, and the amount of body fluid wetback from the absorber increases.
[0049]
【The invention's effect】
The top sheet material for absorbent articles according to the present invention is a three-dimensionally shaped non-woven fabric having a surface with irregularities, and the top surface portion of the tip of the convex portion is formed into a film, and the film-formed portion is a non-woven fabric. Therefore, the amount of wetback or rate of body fluid excreted from the human body can be further reduced as compared with a non-woven fabric that is simply three-dimensionally shaped. Moreover, the top sheet material for absorbent articles according to the present invention is excellent in cushioning properties, flexibility, breathability and touch feeling.
[0050]
Therefore, the top sheet material for absorbent articles according to the present invention is suitable for absorbent articles such as paper diapers and sanitary napkins, and the absorbent article using the top sheet material is a body fluid excreted from the human body. There is no wet feeling due to the wet back, the usability is good, and the top sheet material can be prevented from fuzzing. When this top sheet material for absorbent articles having excellent air permeability is used for top sheets such as disposable diapers and sanitary napkins, rough skin and stuffiness can be prevented.
[0051]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited by these Examples.
[0052]
In addition, the embossing apparatus which consists of the sheet-like composite fiber nonwoven fabric raw material used by the Example etc., a hydrophilic agent coating liquid, and a male-male engagement type embossing roll is as follows.
[Sheet composite fiber nonwoven fabric]
Spunbond nonwoven fabric (SPB) made of core-sheath type composite fiber
This nonwoven fabric was manufactured as follows. That is, the ethylene component content is 5 mol% and the density (ASTM D 1505) is 0.91 g / cm.^Three, MFR (ASTM D 1238, 230 ° C., load 2.16 kg) 50 g / 10 min propylene / ethylene random copolymer, 1-butene content 4 mol%, density (ASTM D 1505) 0.948 g / cm^Three, MFR (ASTM D 1238, 190 ° C, load 2.16 kg) was formed by composite melt spinning using an ethylene / 1-butene random copolymer of 30 g / 10 min. A core and a sheath-core composite fiber of which the sheath is an ethylene / 1-butene random copolymer (core: sheath weight ratio is 5: 5) are deposited on the collecting surface; The basis weight is 23g / m²A spunbond nonwoven fabric (fineness of constituent fibers: 3 denier) was produced.
[Hydrophilic coating solution]
Surfactant manufactured by Toho Chemical Industry Co., Ltd.^TMAS-054C) 1% by weight and a surfactant (Pronal) manufactured by Toho Chemical Co., Ltd.^TM502F) A hydrophilic agent coating solution comprising 1% by weight and 98% by weight of water.
[Embossing device consisting of male and female meshing type embossing rolls]
In this embossing apparatus, as shown in FIG. 5A, convex portions (projections) 6 are arranged in parallel at a predetermined interval in the circumferential direction of the roll, and are spaced at a predetermined interval in the longitudinal direction of the roll. The male embossing rolls 7 arranged in parallel with each other and the female embossing rolls (not shown) meshing with the male embossing rolls 7 are provided. The height of the convex portion 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.
[0053]
Moreover, the physiological saline absorption time, wet-back rate, and surface friction coefficient performed in Examples and the like were measured as follows.
(1) Measuring method of physiological saline absorption time and wetback rate
Peel off the top sheet of a commercially available absorbent article, place the three-dimensional shaped non-woven fabric produced this time as a top sheet on the peeled part, and drop 5 ml of 0.8% physiological saline from the top. Measure the absorption time. After dropping, the solution is allowed to stand for 30 seconds, and 5 ml of 0.8% strength physiological saline is dropped again, and the absorption time of the physiological saline (time until water completely drains from the top sheet to the absorber) is measured.
[0054]
Then, after standing for another 1 minute, 10 sheets of filter paper are stacked on this three-dimensionally shaped nonwoven fabric (top sheet), and a 5 kg weight is further placed thereon, and the amount of water that has returned from the absorber to the filter paper is weighed. , The amount of reversion (wet back amount).
(2) Coefficient of surface friction
About the nonwoven fabric before hot embossing, using a friction tester (Kato Tech Co., Ltd., KES-SE type) at 23 ° C. in the MD direction (longitudinal direction) and CD direction (lateral direction) of the sample surface, MIU (mean static friction coefficient) and MMD (variation of friction coefficient) were measured. The smaller the MIU (mean static friction coefficient) value, the better the surface smoothness.
[0055]
[Example 1]
The hydrophilic agent coating solution is applied to one side of the spunbond nonwoven fabric (SPB) at a coating speed of 10 m / min using a gravure coater (roll diameter: 200 mm, roll mesh: 150 #), and at 85 ° C. for 1 minute. It dried and the hydrophilic processed material of the spun bond nonwoven fabric (SPB) was obtained. The hydrophilic treatment product of the obtained spunbond nonwoven fabric (SPB) is nonwoven fabric 1 m.²The amount of hydrophilic agent (solid content) is 0.5 g / m²The basis weight is 3.5 g / m²The thickness (measured with an optical microscope; the same applies hereinafter) was 152 μm.
[0056]
Subsequently, the hydrophilic treatment product of this spunbond nonwoven fabric (SPB) was embossed under the following conditions using the embossing apparatus to prepare a three-dimensionally shaped nonwoven fabric having a thickness of 2 mm.
[0057]
<Embossing conditions>
Embossing roll surface temperature: 120 ° C
Linear pressure: 70kg / cm
Processing speed: 20m / min
Next, the top sheet (hydrophilic processed product) of a commercially available infant paper diaper (M size) is peeled off, and the three-dimensional shaped non-woven fabric obtained as described above is used as the top sheet instead of this top sheet, as shown in FIG. A paper diaper having a layer structure of topsheet 8 / absorber 9 / backsheet 10 made of a three-dimensionally shaped nonwoven fabric was prepared.
[0058]
About this paper diaper, the said physiological saline absorption time and wet-back rate were measured according to the said method.
The results are shown in Table 1.
[0059]
[Reference Example 1]
In Example 1, it carried out like Example 1 except having produced the paper diaper with the film-form part 1 of the top sheet 8 facing the absorber side.
[0060]
About this paper diaper, the said physiological saline absorption time and wet-back rate were measured according to the said method.
The results are shown in Table 1.
[0061]
[Comparative Example 1]
A paper diaper was produced in the same manner as in Example 1, except that the hydrophilic processed product of the spunbond nonwoven fabric (SPB) of Example 1 was used as it was without performing hot embossing.
[0062]
About this paper diaper, the said physiological saline absorption time and wet-back rate were measured according to the said method.
The results are shown in Table 1.
[0063]
[Table 1]

[Brief description of the drawings]
FIG. 1 is a schematic perspective view for explaining a film-like portion on a top surface of a tip of a convex portion of a top sheet material according to the present invention.
FIG. 2 is a schematic cross-sectional view showing a concentric core-sheath conjugate fiber.
FIGS. 3A and 3B are schematic cross-sectional views showing an eccentric core-sheath type conjugate fiber.
FIG. 4 is a schematic cross-sectional view showing a side-by-side type composite fiber.
FIG. 5A is a schematic partial perspective view of a male embossing roll constituting the embossing apparatus used in the embodiment according to the present invention, and FIG. It is a fragmentary sectional view for demonstrating the shape of the convex part currently formed in the male type | mold embossing roll surface.
FIG. 6 is a partial cross-sectional view showing a layer structure of a disposable diaper obtained in an example according to the present invention.
[Explanation of symbols]
1 ... Film-like part of top surface of top of convex part of top sheet material
2 ... Core
3 ... sheath
4... High melting point component, for example, polymer part made of propylene polymer
5... Low melting point component, for example, polymer part made of ethylene polymer
6 ... Projection (projection) on embossing roll
7 ・ ・ ・ ・ ・ Male embossing roll
8 ・ ・ ・ ・ ・ Top sheet
9 …… Absorber
10 ... Back sheet

Claims (3)

An uneven portion is formed on the surface of the sheet-like hydrophilic treated composite fiber nonwoven fabric by hot embossing, and the upper surface of the tip of the convex portion is formed into a film by melting the composite fiber by the hot embossing . A top sheet material for absorbent articles. The thickness from the top surface of the convex portion to the back surface of the concave portion is 0.2 to 3 mm, the area of the top surface of the convex portion is 0.5 to 30 mm ² , and the area ratio of the convex portion is 10 to 70%. The top sheet material for absorbent articles according to claim 1, wherein the top sheet material is provided. The apparent density (d _F ; g / cm ³ ) of the film-formed portion is 1/2 d _M ≦ d _F ≦ d _M (d _M is the density of the sheet-like hydrophilic treated composite fiber nonwoven fabric before hot embossing ( g / cm ³ ).) The top sheet material for absorbent articles according to claim 1, wherein

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