JP3587831B2 - Surface sheet for absorbent articles - Google Patents

Description

【００４７】
皮膚コンダクタンスの増加量を比較すると、実施例の表面シート（本発明品）は、比較例の表面シートの約半分となっており、本発明の吸収性物品用の表面シートは、比較例の表面シートに対してムレを生じにくいことが判る。
尚、表面シートの製造に用いるエンボスピンの配列は、図７に示すような配列とすることもできる。
【００４８】
【発明の効果】
本発明の吸収性物品用の表面シートは、吸収性物品の着用中にムレを生じさせにくく、ムレによる不快感や、痒み・カブレ等の皮膚トラブルを抑制することができるものである。
【図面の簡単な説明】
【図１】図１は、水平方向への空気透過容量を測定する際に用いるアクリル板等を示す斜視図である。
【図２】図２は、水平方向への空気透過容量を測定する際に用いるガーレー試験機を示す概略模式図である。
【図３】図３は、本発明の吸収性物品用の表面シートの一実施形態を示す斜視図である。
【図４】図４は、図３のＸ−Ｘ模式断面図である。
【図５】図５は、実施例１に用いたエンボスパターンを示す平面図である。
【図６】図６は、実施例２に用いたエンボスパターンを示す平面図である。
【図７】図７は、本発明の表面シートの製造に用い得る他のエンボスパターンを示す平面図である。
【符号の説明】
１ 吸収性物品用の表面シート
２ 第１アクリル板
３ 第２アクリル板
１１ 隆起部
１３ 第１繊維層
１４ 第２繊維層
１５ 熱融着部
１６ 隆起部における熱融着部の隣接部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surface sheet for an absorbent article, and more particularly, to a surface sheet used for a skin contact surface of an absorbent article such as a disposable diaper, a sanitary napkin, an incontinence pad and the like.
[0002]
Problems to be solved by the prior art and the invention
Surface sheets for absorbent articles such as disposable diapers and sanitary napkins have an absorption property that can smoothly transfer excretions from the human body such as urine and menstrual blood to the absorber, as well as discomfort due to stuffiness, Surface characteristics that can prevent skin troubles such as itching and rash are required.
2. Description of the Related Art Conventionally, various types of surface sheets for absorbent articles having an uneven shape formed on a surface of the absorbent article facing the skin side of the wearer have been proposed.
However, most of the irregularities in such a topsheet are designed for the purpose of improving the above-mentioned absorption characteristics and touch such as softness of the skin, and the conventional topsheet has a discomfort due to stuffiness. This leaves room for improvement in preventing skin problems.
[0003]
Japanese Patent Application Laid-Open No. 9-111631 discloses that a multi-wrinkled nonwoven fabric having a large number of wrinkles arranged in a streak on the surface is used as a surface sheet of an absorbent article. However, since the multi-wrinkled nonwoven fabric is easily compressed and deformed in the thickness direction by the mounting pressure, the gap between the wrinkles is easily crushed, so that the air permeability during wearing is impaired, and discomfort due to stuffiness and skin trouble may occur. There is.
[0004]
Japanese Patent Application Laid-Open No. 2000-135239 describes an absorbent article in which a plurality of folds are formed on a skin contact surface of an absorbent article such as a sanitary napkin using a liquid-permeable sheet made of a nonwoven fabric. Japanese Patent No. 3181195 discloses that one of the first and second fiber layers laminated and partially heat-sealed as a nonwoven fabric used as a female material of a hook-and-loop fastener such as a disposable diaper. Accordingly, there is described a nonwoven fabric in which the other protrudes to one side to form a regular convex portion.
[0005]
Also in JP-A-2000-135239, the folds are easily crushed by the mounting pressure, and the air permeability during wearing is impaired. Further, the nonwoven fabric disclosed in Japanese Patent No. 3181195 has a large number of fine irregularities and is easily made of a hard material, so that it not only impairs the wearing feeling of the wearer, but is also sufficient to prevent discomfort and skin trouble due to stuffiness. It cannot be designed. Therefore, it is impossible to use the nonwoven fabric of Japanese Patent No. 3181195 as a surface sheet for an absorbent article.
[0006]
Therefore, an object of the present invention is to provide a surface sheet for an absorbent article, which is less likely to cause stuffiness during wearing of the absorbent article, and which can suppress discomfort due to stuffiness and skin troubles such as itching and rash. Is to do.
[0007]
The present invention relates to a surface sheet used for a skin contact surface of an absorbent article,Each of the first fiber layer and the second fiber layer has a first fiber layer and a second fiber layer each formed of a fiber assembly, and the first fiber layer and the second fiber layer are laminated and partially heat-sealed in a predetermined pattern. Has a protruding portion at a portion other than the heat-sealed portion of the first and second fiber layers, and a portion of the protruding portion adjacent to the heat-sealed portion is formed by heat-sealing the constituent fibers. The rigidity is higher than the other parts of the ridge,10cN / cm^TwoAir permeation capacity in the horizontal direction under pressure is 10 mL / cm^Two-The above object has been achieved by providing a topsheet for an absorbent article, which is characterized by being at least seconds.
[0008]
Further, the present invention provides a topsheet used for a skin contact surface of an absorbent article, the first sheet having a first fiber layer and a second fiber layer each comprising a fiber aggregate, and a first fiber layer and a second fiber layer. Are laminated and partially heat-sealed in a predetermined pattern, and the first fiber layer is provided on a surface of the first and second fiber layers other than the heat-sealed portion and facing the skin side of the wearer. Forming a ridge,The raised portions are formed discontinuously in the MD and CD directions of the sheet, and each raised portion has a ratio of the length in the MD direction to the length in the CD direction (former / latter) of 1/2 to 2 /. 1, 0.5 cN / cm ^Two The thickness of the sheet under pressure is 0.5 to 10 mm, the shortest distance between adjacent raised portions is 0.5 to 15 mm,The ratio (T '/ t) of the substantial thickness T' of the raised portion to the thickness t of the heat-sealed portion is 5 to 50.10 cN / cm ^Two Air permeation capacity in the horizontal direction under pressure is 10 mL / cm ^Two -Seconds or more and 10 cN / cm ^Two Air permeation capacity of sheet in MD direction under pressure, 10 cN / cm ^Two The ratio of the sheet to the air permeation capacity in the CD direction under pressure (the former / the latter) is 0.6 to 1.7.The above object has been achieved by providing a topsheet for an absorbent article.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on preferred embodiments.
The topsheet for an absorbent article of the present invention is used for the skin contact surface (the surface that comes into contact with the wearer's skin) of the absorbent article. The absorbent article has, for example, a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between the two sheets, and is capable of discharging urine, menstrual blood, and other human discharges. And disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., which are absorbed and retained by the absorbent through the topsheet.
[0010]
The topsheet for an absorbent article of the present invention has a great feature in that the air circulation in the horizontal direction (the direction orthogonal to the thickness direction of the sheet) is maintained even under pressure at a predetermined pressure. Have
Specifically, the surface sheet for an absorbent article of the present invention has a thickness of 10 cN / cm.²Air permeation capacity in the horizontal direction under pressure is 10 mL / cm²-Seconds or more, more preferably 50 to 800 mL / cm²Seconds, particularly preferably 100 to 500 mL / cm²-Seconds.
[0011]
10 cN / cm²Air permeation capacity in the horizontal direction under pressure of 10 mL / cm²By setting the time to at least seconds, it is possible to effectively prevent the occurrence of stuffiness while wearing the absorbent article, and to surely prevent skin troubles such as discomfort, itchiness, and rash due to stuffiness. That is, even when the topsheet is pressed against the body of the wearer during the wearing of the absorbent article, sufficient air circulation in the horizontal direction (the direction perpendicular to the thickness direction of the sheet) is sufficiently ensured. Thereby, it is possible to suppress an increase in humidity in the clothes due to excretion and sweating during wearing, and therefore, it is possible to always provide a comfortable wearing feeling without stuffiness and rash.
[0012]
On the other hand, 10 cN / cm²Horizontal air permeation capacity under pressure of 10 mL / cm²-If the time is less than a second, the air circulation in the horizontal direction (the direction perpendicular to the thickness direction of the sheet) is insufficient, and the humidity in the clothes increases due to excretion and sweating while wearing the absorbent article. Skin problems such as itching and rash may occur.
In addition, 10 cN / cm²The upper limit of the horizontal air permeation capacity under pressure is not particularly limited, but is 1000 mL / cm from the viewpoint of the surface design of the topsheet that can be adhered to the wearer to such an extent that no trouble such as liquid flow occurs.²・ It is on the order of seconds.
[0013]
10cN / cm²The air transmission capacity in the horizontal direction under pressure is measured by the following method.
First, 10 cN / cm²The thickness T1 of the topsheet for an absorbent article under pressure is measured.
Then, as shown in FIG. 1, the topsheet for an absorbent article was cut into a square shape with a side of 50 mm, and the obtained measurement piece 1 was cut into a square shape having a square opening 21 with a side of 10 mm in the center. Between the first acrylic plate (dimensions: 50 mm × 50 mm × 3 mm) 2 and the second acrylic plate 3 having the same configuration as the first acrylic plate 2 except that it has no opening, The surface facing the skin side (the surface on which the protruding portions 11 are present) is sandwiched by the first acrylic plate 2 to form a laminate for measurement 10 (see FIG. 2), which is, as shown in FIG. The first acrylic plate 2 side is set under the gasket 4 of the Gurley tester (B type) specified in 8117 “Gurley tester method” until the measurement piece 1 reaches the thickness T1. Compress.
Next, the time required for introducing air through the opening 21 to introduce 300 mL of air into the central portion of the measuring piece 1 whose thickness is maintained at T1 is measured.
Then, the unit area of the opening 21 (1 cm²) × Calculate the amount of air introduced per second (mL), and apply a load of 10 cN / cm.²The air permeation capacity in the horizontal direction under pressure.
[0014]
10cN / cm²The thickness T1 of the topsheet for an absorbent article under pressure can be measured as follows.
The thickness T1 is measured using a KES measuring device (for example, a product name “KES-FB series” manufactured by Kato Tech Co., Ltd., model “KES-BF3”). The KES measuring device is a tester that can sandwich a measuring piece between a pressure plate and a pressure receiving plate and compressively deform the measuring piece at a constant speed in a thickness direction.
First, a topsheet for an absorbent article is cut into a predetermined size (a size larger than the pressure plate) and set on the pressure receiving plate. Then, the pressure plate is lowered at a speed of 1.2 mm / min, and the measurement piece is compressed between the pressure plate and the pressure receiving plate.
The maximum value of the load applied to the test piece is 50 cN / cm²And the load applied to the measurement piece is 50 cN / cm²The distance between the pressure plate and the pressure receiving plate and the load applied to the measurement piece were measured until the load reached 10 cN / cm during the compression process.²The distance between the pressure plate and the pressure receiving plate (= thickness of the measuring piece) at the time when²The thickness T1 of the topsheet under pressure is assumed.
[0015]
As a Gurley tester specified in JIS P 8117 “Gurley tester method”, for example, “Gurley Densometer” manufactured by Kumagaya Riki Kogyo Co., Ltd. shown in FIG. 2 is used.
In order to compress the measurement laminate 10 and introduce air under the compressed state using the apparatus of FIG. 2, first, the measurement laminate 10 is placed with the first acrylic plate 2 side facing upward. By positioning the sample clamping handle 5 below the gasket 4 and rotating the sample tightening handle 5, the gap between the gasket 4 and the opposing surface 6 of the gasket 4 is adjusted so that the measurement piece 1 has a target load thickness (the thickness T <b> 1). Adjust clearance. In the figure, reference numeral 7 denotes a silicon plate (hardness 50) having a square opening 71 with a side of 10 mm at the center, in order to prevent the introduced air from leaking from other than the edge of the measuring piece 1. It is interposed between the gasket 4 and the first acrylic plate 2.
Then, the pull-up knob 81 is pinched, the inner cylinder 8 is pulled up, a predetermined amount of outside air is sucked into the cylinder (the outer cylinder 9), and then the inner cylinder 8 is lowered into the outer cylinder 9. Thus, 300 ml of air is introduced from the air supply port (not shown) at the center of the lower surface of the gasket 4 onto the center of the test piece 1 (pressure depends on the mass of the inner cylinder). Then, the time from the start of introduction of air to the completion of introduction of 300 mL of air was measured, and the load was 10 cN / cm.²Calculate the air permeation capacity in the horizontal direction under pressure. In the drawing, reference symbol S denotes a light emitting and receiving sensor, and a signal is transmitted between the light emitting and receiving sensors by passing a strip-shaped slit plate (having a preset slit point) attached to the inner cylinder between the sensors. The time is sent to a digital counter, and the time is digitally displayed.
[0016]
The topsheet for an absorbent article of the present invention has a cN / cm of 50 cN / cm.²Air permeation capacity in the horizontal direction under pressure is 10 to 500 mL / cm²・ Seconds, especially 20 to 200 mL / cm²-It is preferably seconds.
50 cN / cm²Air permeation capacity in the horizontal direction under pressure is 10 mL / cm²-If the time is more than seconds, even when the topsheet is significantly pressurized while wearing the absorbent article and is in close contact with the wearer's body, the air permeability in the horizontal direction is sufficiently maintained, and discomfort due to stuffiness and Skin problems such as itching and rash can be further prevented. The air permeation capacity is 500 mL / cm.²When the time is less than the second, it is possible to suppress a feeling of discomfort during wearing and to prevent a decrease in absorption performance such as a liquid flow on the surface.
[0017]
50 cN / cm²The method for measuring the air transmission capacity in the horizontal direction under pressure is 50 cN / cm²The above-described load 10 cN / cm, except that the thickness T2 of the topsheet for an absorbent article under pressure is measured in advance, and air is introduced into the measurement piece 1 whose thickness is maintained at T2.²This is similar to the measurement of the air transmission capacity in the horizontal direction under pressure.
[0018]
The surface sheet for the absorbent article of the present invention has a cN / cm of 10 cN / cm.²It is preferable that the difference in the air permeation capacity in the horizontal direction under pressure between the MD direction and the CD direction is small. Specifically, 10 cN / cm²Air permeation capacity of sheet in MD direction under pressure, 10 cN / cm²The ratio of the sheet to the air permeation capacity in the CD direction under pressure (the former / the latter) is preferably 0.6 to 1.7, more preferably 0.8 to 1.5, and particularly preferably. 0.9 to 1.2. When the ratio is in the range of 0.6 to 1.7, the air circulation in the MD direction and the CD direction is sufficiently ensured, and the wearer follows all possible postures of the wearer, so that an optimal stuffiness-free environment is achieved. Can be provided.
[0019]
In the present specification, the MD direction and the CD direction of the sheet refer to the flow direction (MD direction) of the raw material and the direction (CD direction) orthogonal to the flow direction in the production line of the topsheet for the absorbent article. means. However, when there is no distinction between the MD direction and the CD direction, the longitudinal direction of the sheet is the MD direction, and the lateral direction is the CD direction. If the MD direction and the CD direction cannot be distinguished from each other and the longitudinal direction and the transverse direction cannot be distinguished, any one direction of the top sheet is defined as the MD direction and the direction orthogonal thereto is defined as the CD direction.
[0020]
10cN / cm²The method of measuring the air permeation capacity of the sheet in the MD direction and the CD direction under pressure is as follows: two sets of two opposing sides of the measurement laminate 10 in which the measurement piece 1 is sandwiched between two acrylic plates 2 and 3 The above-mentioned load is 10 cN / cm, except that any one of them is sealed with clay or the like so that air does not leak.²This is similar to the measurement of the air transmission capacity in the horizontal direction under pressure.
Opposite two sides sealed with clay or the like are two sides along the MD direction of the sheet (two sides located at both ends in the CD direction) when measuring the air permeation capacity of the sheet in the MD direction. When measuring the air permeation capacity of the sheet in the CD direction, two sides along the CD direction of the sheet (two sides located at both ends in the MD direction) are used.
[0021]
From the viewpoint of improving the air permeation capacity in the horizontal direction, 10 cN / cm²The thickness T1 of the topsheet for an absorbent article under pressure is preferably 0.5 to 5 mm, particularly preferably 0.8 to 4 mm. In addition, from the same viewpoint, 50 cN / cm²The thickness T2 of the topsheet for an absorbent article under pressure is preferably 0.3 to 4 mm, particularly preferably 0.5 to 3 mm.
[0022]
FIGS. 3 and 4 are views showing a specific structure of a topsheet for an absorbent article as a preferred embodiment of the present invention.
The topsheet 1 for an absorbent article of the present embodiment has a large number of raised portions 11 that are discontinuous in the MD and CD directions of the sheet on a surface C facing the wearer's skin side. Each protruding portion 11 has substantially the same length in the MD direction and the CD direction (length in the MD direction / length in the CD direction = about 1/2 to 2/1).
[0023]
The thickness T (see FIG. 4) of the topsheet of the present embodiment (see FIG. 4) is preferably 0.5 to 10 mm, particularly preferably 1 to 5 mm, and the shortest distance L1 between the adjacent raised portions 11, 11 is preferred. (See FIG. 4) is preferably 0.5 to 15 mm, particularly preferably 1 to 10 mm.
[0024]
By setting the thickness T of the top sheet to 0.5 mm or more and the shortest distance L1 between the ridges to 1 mm or more, a valley having a size large enough to allow air to flow between the ridges 11 can be formed. It is possible to easily and sufficiently secure the air permeation capacity in the horizontal direction under pressure.
Further, by setting the thickness T to 10 mm or less, the feeling of discomfort during wearing can be suppressed while maintaining the texture (softness or the like) of the topsheet.
Further, by setting the shortest distance L1 to 15 mm or less, the absorption performance is maintained while securing sufficient air permeation capacity in the horizontal direction under pressure (by ensuring the minimum contact area with the skin). Can be.
[0025]
The thickness T of the topsheet is measured as follows.
Measured in the same way with the above KES measuring instrument, and 0.5 cN / cm²The distance between the pressure plate and the pressure receiving plate at the time of (initial pressure) is defined as the thickness (thickness at the raised portion) T of the topsheet.
[0026]
As shown in FIG. 4, the topsheet 1 for an absorbent article of the present embodiment includes a first fiber layer 13 and a second fiber layer 14 each formed of a fiber aggregate.
The first fiber layer 13 and the second fiber layer 14 are laminated and partially heat-sealed in a predetermined pattern. This heat fusion is heat fusion by hot embossing. More specifically, after laminating the fiber aggregates constituting the first and second fiber layers, a large number of pins are regularly arranged. The constituent fibers of the first fiber layer 13 and / or the second fiber layer 14 at the portions heated and pressed by the pins are brought into contact with the embossed surface (the peripheral surface of the emboss roll, etc.) against the first fiber layer side. It is melted and heat-sealed.
The topsheet 1 is formed with heat-fused portions 15, 15,.
Further, by shrinking the second fiber layer in the horizontal direction after the above-described hot embossing, the top sheet 1 has a large number of ridges made of the first fiber layer at portions other than the heat-sealed portions 15, 15,. 11 and 11 are formed.
[0027]
In the topsheet 1 for an absorbent article according to the present embodiment, at the time of the above-described hot embossing, the portion adjacent to the heat fusion portion (the portion directly pressed to the tip of the pin) 15 in the first fiber layer 13 is formed. Also, since heat is applied by the pins (since the peripheral surfaces of the pins are in contact with each other), the constituent fibers of the first fiber layer 13 are fused and the fibers are fused together also in the adjacent portion 16.
Therefore, in the state where the raised portion 11 is generated by the contraction of the second fiber layer 14, the adjacent portion 16 of the raised portion 11 adjacent to the heat-sealed portion 15 is more compact than other portions (near the top) of the raised portion 11. And its rigidity is high.
By increasing the rigidity of the adjacent portion 16, the shape retention of the raised portion is improved, and the raised portion 11 is not crushed under pressure and easily spreads to the heat-sealed portion. Obtained. In addition, as a method of consolidating the adjacent portion 16 of the heat-sealed portion 15, another fixing method such as an ultrasonic seal may be adopted.
[0028]
The ratio (T '/ t) of the substantial thickness T' of the raised portion 11 to the thickness t of the heat-sealed portion 15 is 5 to 50, particularly 8 to 30 in order to increase the rigidity by consolidating the adjacent portion 16. It is preferable that
The substantial thickness T ′ of the raised portion 11 is the total thickness of the first fiber layer 13 and the second fiber layer 14 and has a space between the first fiber layer 13 and the second fiber layer 14. In the maximum thickness portion forming the apex of the ridge 11, the thickness of the first fiber layer 13 and the thickness of the second fiber layer 14 are measured and totaled to obtain the substantial thickness T '. When the first fiber layer 13 and the second fiber layer 14 are in contact with each other at the raised portion 11, the thickness of the maximum thickness portion forming the apex of the raised portion 11 is substantially the thickness T '. Is substantially the same as the above-mentioned thickness (thickness at the raised portion) T of the topsheet, the value of the thickness T of the topsheet can be used instead of the substantial thickness T ′.
[0029]
The thickness t of the heat-sealed portion 15 and the substantial thickness T 'of the raised portion are measured from a cross-sectional photograph or a cross-sectional image of the topsheet in a non-pressurized state. In this example, the sample was cut so as to pass through the top of the raised portion and the heat-sealed portion, and the cross-sectional shape of the sample was measured using a microscope VH-8000 manufactured by KEYENCE CORPORATION. And the substantial thickness T 'of the raised portion was measured.
By controlling the thickness t of the heat-sealed portion 15 of the topsheet with respect to the substantial thickness T 'of the raised portion, the consolidation of the adjacent portion 16 is improved and the rigidity is increased. In the present embodiment, the thickness t of the heat-sealed portion 15 is preferably 0.01 to 1 mm, particularly preferably 0.1 to 0.5 mm from the above viewpoint.
[0030]
The heat-sealed portions 15 in the topsheet 1 of the present embodiment are circular in plan view, and the topsheet 1 is formed with a large number of circular heat-sealed portions 15 regularly formed in a scattered manner. I have. The distance between the heat-sealed portions 15 is substantially constant. The first fiber layer 13 in each region surrounded by the four heat-sealed portions projects upward to form a large number of the raised portions 11. Each raised portion 11 has a dome shape, and the inside is filled with the fibers constituting the first fiber layer.
The first fiber layer 13 and the second fiber layer 14 are different in the composition of constituent fibers and / or fibers. In addition, since both the first fiber layer and the second fiber layer are formed of a fiber aggregate, the topsheet 1 has air permeability in the thickness direction as a whole.
From the viewpoint of improving the air permeation capacity in the horizontal direction, the number of pins provided on the embossed surface (peripheral surface of the emboss roll) for forming the heat-sealed portion is 1 cm.²Per unit is preferably 1 to 15, particularly 3 to 10. Further, in the present embodiment, from the viewpoint of improving the air permeation capacity in the horizontal direction and the liquid absorbing property, the heat-sealed portion of the topsheet 1 after heat shrinkage is 1 cm.²Per unit number is preferably 1 to 30, especially 5 to 20.
[0031]
As a fiber constituting the first fiber layer, a fiber made of a thermoplastic polymer material is suitably used. Examples of the thermoplastic polymer material include polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, and polyamide. Also, a core-sheath type composite fiber or a side-by-side type composite fiber composed of a combination of these thermoplastic polymer materials can be used. The fibers constituting the first fiber layer 13 may be substantially non-heat-shrinkable or may not be heat-shrinkable at or below the heat-shrinking temperature of the fibers constituting the second fiber layer 14 described below. preferable.
[0032]
As the fiber constituting the second fiber layer, a fiber made of a thermoplastic polymer material and having heat shrinkability is suitably used. Further, as the fibers, fibers exhibiting an elastomeric behavior are preferably used. Examples of such fibers include latently crimpable fibers. Latent crimpable fibers can be handled in the same manner as conventional nonwoven fabric fibers before being heated, and have the property of developing a helical crimp and shrinking by heating at a predetermined temperature. is there. The latently crimpable fiber is composed of, for example, an eccentric core-sheath type composite fiber or a side-by-side type composite fiber containing two kinds of thermoplastic polymer materials having different shrinkage rates. Examples thereof include those described in JP-A-9-296325 and JP-A-2759331. The second fiber layer contains such latently crimpable fibers, for example, and is shrunk by crimping of the fibers by heating.
In the first and second fiber layers, fibers other than those described above, for example, water-absorbing fibers such as rayon, cotton, and hydrophilized acrylic fibers can be mixed.
[0033]
Examples of the form of the fiber aggregate constituting the first fiber layer include a web formed by a card method, a combination of the web and a nonwoven fabric by various manufacturing methods, and the like.
The form of the aggregate of the fibers constituting the second fiber layer includes (1) a web containing latent crimpable fibers and formed by a card method, and (2) a heat-shrinkable nonwoven fabric as a heat-sealing method. Nonwoven fabrics formed by the hydroentanglement method, nonwoven fabrics formed by the needle punch method, nonwoven fabrics formed by the solvent bonding method, nonwoven fabrics formed by the spunbond method, nonwoven fabrics formed by the meltblown method, etc. Is mentioned. Here, the non-woven fabric having heat shrinkability is a non-woven fabric having a property of shrinking by heating at a predetermined temperature. Further, (3) a net or the like having heat shrinkage can be used instead of the fiber aggregate.
[0034]
The basis weight of the first fiber layer 13 is 5 to 60 g / m.², Especially 10 to 40 g / m²Is preferable from the viewpoint of forming a raised portion having a sufficient height to increase the air permeation capacity in the horizontal direction. The basis weight of the second fiber layer 14 is 5 to 50 g / m.², Especially 10 to 30 g / m²Is preferable from the viewpoint of exhibiting sufficient heat shrinkage to raise the first fiber layer and not to impair the absorption performance of the sheet. Here, the basis weight of the first and second fiber layers means the basis weight of each layer before joining the first fiber layer and the second fiber layer.
The basis weight of the first fiber layer 13 after forming the raised portion (after heat shrinking) is 10 to 90 g / m.²Especially 20 to 80 g / m²This is preferable from the viewpoint of improving the air permeability in the horizontal direction and the formability of the raised portion.
The basis weight of the topsheet 1 of the present invention is 15 to 200 g / m.², Especially 30 to 150 g / m²It is preferable from the viewpoints of the air permeation capacity in the horizontal direction, the shape retention of the raised portion, the absorption performance, and the like.
[0035]
The topsheet 1 of the present invention may be provided with a large number of apertures. For example, it is preferable to provide an opening having a diameter of 0.2 to 10 mm in the first and / or second fiber layer in the above embodiment. By providing such an opening, the permeability of bodily fluids such as urine, menstrual blood, and stool is improved, and the occurrence of leakage and stuffiness is further reduced.
[0036]
The invention is not limited to the embodiments described above. For example, the same or different fiber layer as the first fiber layer may be formed on the surface of the second fiber layer 14 opposite to the first fiber layer 13 in the topsheet of the embodiment. Further, the topsheet may be composed of a single fiber layer composed of a fiber aggregate.
Further, other than the fiber aggregate, it may be one or more layers of a material that can substantially pass air, such as a breathable film, an apertured film, a net, or These composites, or composites of these with a fiber aggregate, and the like are included.
[0037]
[Example 1]
(1) Production of the first fiber layer
Using a core-sheath type composite fiber NBF (SH) (trade name, 2.2 dtex × 51 mm) manufactured by Daiwa Spinning Co., Ltd. as a raw material, a grammage of 25 g / m 2 is obtained by a card method.²Was manufactured and used as the first fiber layer. The core-sheath type composite fiber NBF is a fiber having polyethylene terephthalate (PET) as a core component and polyethylene (PE) as a sheath component.
[0038]
(2) Production of the second fiber layer
A latent spiral crimped fiber (CPP fiber (trade name), 2.2 dtex × 51 mm) manufactured by Daiwa Spinning Co., Ltd. was used as a raw material, and the grammage was 25 g / m2 by the card method.²Was manufactured and used as the second fiber layer.
[0039]
(3) Manufacture of topsheet
The first fiber layer and the second fiber layer were overlapped, and both were partially heat-sealed in a predetermined pattern by hot embossing (heat sealing). The hot embossing was performed by pressing an embossed surface on which a large number of pins are regularly arranged in a pattern shown in FIG. 5 against the first fiber layer side. The sealing conditions were 220 ° C. for 10 seconds. Each pin in FIG. 5 has a diameter of 1.5 mm, and the distance between the center points of adjacent pins is 6 mm.
Then, the obtained heat-sealed body of both fiber layers is left in an electric drier at 130 ° C. for 10 minutes to crimp the latent spirally crimped fiber of the second fiber layer to shrink the second fiber layer. At the same time, the first fiber layer was projected in a convex shape at a portion other than the heat-sealed portion to obtain a topsheet for an absorbent article having a large number of raised portions and having the form shown in FIGS. 3 and 4.
The obtained topsheet is 0.5 cN / cm²The thickness T under pressure (the thickness at the raised portion) T was 3.1 mm, and the shortest distance L1 between adjacent raised portions was 1 to 1.5 mm. Further, the portion of the protruding portion adjacent to the heat-sealed portion had higher rigidity than the other portions of the protruding portion because the core-sheath type composite fiber was fused together by fusion of the sheath components. .
[0040]
[Example 2]
A surface sheet for an absorbent article was manufactured in the same manner as in Example 1 except that the embossed surface having the pattern shown in FIG. 6 was used for the heat embossing.
The obtained topsheet is 0.5 cN / cm²The thickness T under pressure (thickness at the raised portion) T was 2.3 mm, and the shortest distance L1 between adjacent raised portions was 1 to 1.5 mm. Further, in the portion adjacent to the heat-sealed portion in the raised portion, the fibers were fused together, and the rigidity was higher than in other portions of the raised portion.
[0041]
[Comparative Examples 1 and 2]
Used as a surface sheet used for commercially available sanitary napkins (trade name "Laurier Soft Mesh", manufactured by Kao Corporation) and a commercially available sanitary napkin (trade name "Laurier Dry Up Mesh" manufactured by Kao Corporation) A prepared topsheet was prepared.
[0042]
[Comparative Example 3]
A nonwoven fabric sheet (basis weight 25 g / m2) obtained from a core-sheath type composite fiber (core PET / sheath PE = 40/60 (volume ratio), fineness 2.2 dtex) manufactured by Daiwa Spinning Co., Ltd.²1) hot melt having a width of 1 mm was applied at a pitch of 2 mm (1 mm interval) so as to be arranged in the MD direction of the nonwoven fabric sheet.
Then, the same nonwoven fabric sheet as the above nonwoven fabric sheet is pressed against a concavo-convex forming die in which convex strips having a height of 1 mm and a width of 1 mm are arranged in parallel at a pitch of 2 mm (interval of 1 mm), and deformed into a substantially bellows shape. The laminate was bonded to the above-mentioned nonwoven fabric sheet previously coated with hot melt.
In the obtained topsheet, a large number of ridges having a width of 1 mm are formed at a pitch of 2 mm, the width of the joint between the nonwoven fabric sheets is 1 mm, and 0.5 cN / cm²The thickness T under pressure (the thickness at the ridge) T was 0.9 mm, and the projection height of the ridge was 0.7 mm.
[0043]
[Comparative Example 4]
A surface sheet for an absorbent article was manufactured in the same manner as in Example 1 except that the pin diameter was 1 mm and the distance between the center points of adjacent pins was 1 mm. The obtained topsheet is 0.5 cN / cm²The thickness T under pressure (the thickness at the raised portion) T was 0.5 mm, and the shortest distance L1 between adjacent raised portions was 0.7 mm.
[0044]
[Measurement of air transmission capacity]
10 cN / cm for each surface sheet of Examples and Comparative Examples²Under pressure and 50 cN / cm²Air permeation capacity in the horizontal direction under pressure, as well as 10 cN / cm²The air permeation capacity in the MD direction and the CD direction in the horizontal direction under pressure was measured by the method described above, and the results are shown in Table 1.
[0045]
[Performance evaluation (measurement of skin conductance increase)]
6 g of water was injected into the surface of the topsheet cut to 50 mm x 75 mm facing the skin side of the wearer, and the surface was turned to the skin side and fixed to the inside of the forearm of the human body with a bandage. Then, two hours after the fixation, the skin conductance was measured.
The difference between that value and the value of skin conductance before fixation was defined as the increase in skin conductance, and the results are also shown in Table 1.
The skin conductance was measured using a Skin Surface Hydrometer (SKICON 200) manufactured by IBS Co. Ltd.
[0046]
[Table 1]

[0047]
Comparing the increase in the skin conductance, the surface sheet of the example (product of the present invention) is about half the surface sheet of the comparative example, and the surface sheet for the absorbent article of the present invention is the surface sheet of the comparative example. It can be seen that the sheet is hardly stuffy.
The arrangement of embossing pins used for manufacturing the topsheet may be an arrangement as shown in FIG.
[0048]
【The invention's effect】
The topsheet for an absorbent article of the present invention is less likely to cause stuffiness while wearing the absorbent article, and can suppress discomfort due to stuffiness and skin troubles such as itching and rash.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an acrylic plate and the like used for measuring an air transmission capacity in a horizontal direction.
FIG. 2 is a schematic diagram showing a Gurley tester used for measuring the air permeation capacity in the horizontal direction.
FIG. 3 is a perspective view showing one embodiment of a topsheet for an absorbent article of the present invention.
FIG. 4 is a schematic sectional view taken along line XX of FIG. 3;
FIG. 5 is a plan view showing an emboss pattern used in Example 1.
FIG. 6 is a plan view showing an emboss pattern used in Example 2.
FIG. 7 is a plan view showing another emboss pattern that can be used for manufacturing the topsheet of the present invention.
[Explanation of symbols]
1 Surface sheet for absorbent articles
2 First acrylic board
3 Second acrylic board
11 ridge
13 First fiber layer
14 Second fiber layer
15 Heat fusion part
16 Adjacent part of the heat-sealed part in the protruding part

Claims (5)

In the surface sheet used for the skin contact surface of the absorbent article,
Each of the first fiber layer and the second fiber layer has a first fiber layer and a second fiber layer each formed of a fiber assembly, and the first fiber layer and the second fiber layer are laminated and partially heat-sealed in a predetermined pattern. Has a protruding portion at a portion other than the heat-sealed portion of the first and second fiber layers, and a portion of the protruding portion adjacent to the heat-sealed portion is formed by heat-sealing the constituent fibers. The rigidity is higher than the other parts of the ridge,
A surface sheet for an absorbent article, wherein the air permeation capacity in a horizontal direction under a pressure of 10 cN / cm ² is 10 mL / cm ² · second or more. The substantial thickness T of the raised portion with respect to the thickness t of the heat-sealed portion ' Ratio (T ' The surface sheet for an absorbent article according to claim 1, wherein (t) is from 5 to 50. In the surface sheet used for the skin contact surface of the absorbent article,
Each of the first fiber layer and the second fiber layer has a first fiber layer and a second fiber layer each formed of a fiber assembly, and the first fiber layer and the second fiber layer are laminated and partially heat-sealed in a predetermined pattern. Forms a raised portion on the surface of the first and second fiber layers other than the heat-sealed portion, facing the wearer's skin,
The ridges are formed discontinuously in the MD and CD directions of the sheet, and each ridge has a ratio of the length in the MD direction to the length in the CD direction (former / latter) of 1/2 to 2 /. 1 and
The thickness of the sheet under a pressure of 0.5 cN / cm ² is 0.5 to 10 mm, the shortest distance between adjacent raised portions is 0.5 to 15 mm, and the height of the sheet relative to the thickness t of the heat-sealed portion is increased. The ratio (T ′ / t) of the substantial thickness T ′ of the portion is 5 to 50,
10 cN / cm ² air permeation capacity in the horizontal direction under pressure is not less 10 mL / cm ² · sec or more and an air permeation capacity of the MD direction of the sheet under 10 cN / cm ² pressure, 10 cN / cm ² pressure A surface sheet for an absorbent article, wherein the ratio of the lower sheet to the air permeation capacity in the CD direction (the former / the latter) is 0.6 to 1.7 . The surface sheet for an absorbent article according to any one of claims 1 to 3 , wherein an air permeation capacity in a horizontal direction under a pressure of 50 cN / cm ² is 10 to 500 mL / cm ² · second. The surface sheet for an absorbent article according to any one of claims 1 to 4 , wherein the air permeation capacity in a horizontal direction under a pressure of 10 cN / cm ² is 50 to 800 mL / cm ² · sec.

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