WO2023042540A1 - Spunbonded nonwoven fabric and sanitary material - Google Patents

Spunbonded nonwoven fabric and sanitary material Download PDF

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Publication number
WO2023042540A1
WO2023042540A1 PCT/JP2022/028000 JP2022028000W WO2023042540A1 WO 2023042540 A1 WO2023042540 A1 WO 2023042540A1 JP 2022028000 W JP2022028000 W JP 2022028000W WO 2023042540 A1 WO2023042540 A1 WO 2023042540A1
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WIPO (PCT)
Prior art keywords
nonwoven fabric
spunbond nonwoven
fused portion
fused
present
Prior art date
Application number
PCT/JP2022/028000
Other languages
French (fr)
Japanese (ja)
Inventor
森岡英樹
勝田大士
梶原健太郎
Original Assignee
東レ株式会社
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Application filed by 東レ株式会社 filed Critical 東レ株式会社
Priority to KR1020247006777A priority Critical patent/KR20240054276A/en
Priority to JP2022544073A priority patent/JP7226659B1/en
Priority to CN202280059456.8A priority patent/CN117897525A/en
Publication of WO2023042540A1 publication Critical patent/WO2023042540A1/en

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    • A—HUMAN NECESSITIES
    • A41—WEARING APPAREL
    • A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
    • A41D13/00—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches
    • A41D13/05—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches protecting only a particular body part
    • A41D13/11—Protective face masks, e.g. for surgical use, or for use in foul atmospheres
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/51—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers
    • A61F13/511—Topsheet, i.e. the permeable cover or layer facing the skin
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/51—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers
    • A61F13/514—Backsheet, i.e. the impermeable cover or layer furthest from the skin
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
    • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion

Definitions

  • the present invention relates to a spunbond nonwoven fabric that is excellent in dryness and quick-drying properties and is particularly suitable for use as sanitary materials, and sanitary materials using the same.
  • the key to comfort is to quickly remove moisture such as urine and sweat and keep the surface that touches the skin dry.
  • Patent Document 1 proposes a nonwoven fabric in which a fiber layer (skin surface side) made of fine fineness fibers and a fiber layer made of large fineness fibers are laminated and partially entangled at the interface.
  • sheets having different average non-fiber-occupied voids are laminated according to the difference in the mixing ratio and fiber diameter of a plurality of fibers, and the average non-fiber-occupied voids of the first layer that comes in contact with the skin are reduced from the layers other than the first layer.
  • a sheet with a larger diameter is also proposed.
  • the fiber layer made of fine fibers on the skin side has a denser structure than the other layers, so moisture tends to remain in the fiber layer on the skin side, resulting in dryness. is difficult to obtain.
  • the dense fiber layer on the skin side reduces the liquid permeability, making it impossible to rapidly absorb water, making it difficult to obtain water absorbency.
  • the spunbond nonwoven fabric of the present invention has the following constitution. i.e. It has a fused portion and a non-fused portion, and on one surface (A), the fused portion forms a recess facing the other surface (B), and constitutes the one surface (A).
  • the ratio (Da/Db) of the average single fiber diameter (Da) of the fibers to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more, and the following conditions are satisfied: is a spunbond nonwoven, which satisfies.
  • the diameter of the minimum inscribed circle of the unfused portion is 1.0 mm or less
  • the diameter of the maximum inscribed circle of the unfused portion is 2.0 mm or more
  • the fused portion (4)
  • the ratio (Tm/T) of the thickness (Tm) of the spunbond nonwoven fabric to the thickness (T) of the spunbond nonwoven fabric in the fused portion is 0.30 or less.
  • the fused portion has an irregularity of 1.1 or more.
  • the sanitary material of the present invention has the following constitution. i.e. A sanitary material at least partially composed of the spunbond nonwoven fabric.
  • the diameter of the maximum inscribed circle of the non-fused portion is preferably 10.0 mm or less.
  • the spunbonded nonwoven fabric of the present invention preferably has the fused portions arranged intermittently.
  • the diameter of the minimum inscribed circle of the non-fused portion is 0.2 mm or more.
  • both the surface (A) and the surface (B) have contact angles with water of 30° or less.
  • the sanitary material of the present invention is preferably a diaper.
  • the sanitary material that is the diaper of the present invention, it is preferable that at least part of the sanitary material is a topsheet.
  • the at least part is preferably at least part of the waist portion.
  • the sanitary material of the present invention is preferably a mask.
  • the at least part of the sanitary material is the inner surface layer of the mask.
  • the present invention it is possible to obtain a spunbond nonwoven fabric that has sufficient water absorbency and dryness to be used as a nonwoven fabric for sanitary materials and has excellent quick-drying properties.
  • FIG. 4 is a conceptual top view illustrating a method of determining the maximum and minimum inscribed circles of the non-fused portion in one embodiment of the spunbond nonwoven fabric of the present invention.
  • FIG. 4 is a conceptual top view illustrating a method of determining the maximum inscribed circle and the minimum inscribed circle of the non-fused portion in another embodiment of the spunbond nonwoven fabric of the present invention.
  • FIG. 4 is a top view conceptual diagram illustrating a method of determining the maximum inscribed circle and the minimum inscribed circle of the non-fused portion in still another embodiment of the spunbond nonwoven fabric of the present invention.
  • FIG. 3 is a top conceptual view illustrating a method for determining whether the fused portions in one embodiment of the spunbond nonwoven fabric of the present invention are arranged in rows.
  • FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Example 2 of the spunbond nonwoven fabric of the present invention.
  • FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Example 3 of the spunbond nonwoven fabric of the present invention.
  • FIG. 4 is a schematic diagram illustrating the pattern of the embossing roll used in Example 4 of the spunbond nonwoven fabric of the present invention.
  • FIG. 4 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 4 of the spunbond nonwoven fabric of the present invention.
  • FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 5 of the spunbond nonwoven fabric of the present invention.
  • FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 6 of the spunbond nonwoven fabric of the present invention.
  • FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 7 of the spunbond nonwoven fabric of the present invention.
  • the spunbond nonwoven fabric of the present invention has a fused portion and a non-fused portion.
  • the ratio (Da/Db) of the average single fiber diameter (Da) of the fibers constituting the other surface (A) to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more and satisfies the following conditions:
  • the diameter of the minimum inscribed circle of the non-fused portion is 1.0 mm or less.
  • the diameter of the maximum inscribed circle of the non-fused portion is 2.0 mm or more.
  • the ratio (Tm/T) between the thickness (Tm) of the spunbond nonwoven fabric and the thickness (T) of the spunbond nonwoven fabric in the fused portion is 0.30 or less.
  • the irregularity of the fused portion is 1.1 or more.
  • the fibers constituting the spunbonded nonwoven fabric of the present invention are made of a thermoplastic resin as usual.
  • a thermoplastic resin may be used, or a plurality of thermoplastic resins may be used.
  • thermoplastic resins used for fibers constituting the spunbond nonwoven fabric of the present invention include aromatic polyester polymers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, and copolymers thereof; Aliphatic polyester polymers such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, polycaprolactone and copolymers thereof; polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 12, polyamide 6-12 and other aliphatic polyamide polymers and their copolymers; polypropylene, polyethylene, polybutene, polymethylpentene and other polyolefin polymers and their copolymers, ethylene units Water-insoluble ethylene-vinyl alcohol copolymer containing 25 mol% to 70 mol%, polystyrene, polydiene,
  • additives such as inorganic substances such as titanium oxide, silica, and barium oxide, carbon black, colorants such as dyes and pigments, flame retardants, fluorescent brighteners, antioxidants, and ultraviolet absorbers may be added to the above polymers.
  • Agents may be included in the polymer.
  • a fatty acid amide compound having 15 or more and 50 or less carbon atoms may be contained.
  • a hydrophilizing agent may be contained.
  • the fibers constituting the spunbond nonwoven fabric of the present invention may be not only monocomponent fibers, but also composite fibers obtained by combining two or more types of resins.
  • the above fiber is a composite fiber, it is not particularly limited as long as it does not impair the effects of the present invention, and may be appropriately selected from a core-sheath type, a sea-island type, a side-by-side type, an eccentric core-sheath type, and the like. Further, it may be a split fiber type conjugate fiber in which a part or the whole of a single fiber is split into a plurality of fibers.
  • the cross-sectional shape of the fiber according to the present invention is not particularly limited as long as it does not impair the effects of the present invention, and may be a circular cross-section, as well as an irregular cross-section such as triangular, flat, hexagonal, or hollow.
  • the fibers constituting the spunbond nonwoven fabric of the present invention preferably have a contact angle with water of 90° or less.
  • the contact angle with water on the fiber is an index different from the contact angle with water on the surface of the nonwoven fabric, which will be described later. If the contact angle exceeds 90°, it is hydrophobic, and if it is 90° or less, it is hydrophilic.
  • the contact angle with water on the surface of the nonwoven fabric can be easily reduced to 30° or less.
  • the contact angle of the fiber of the present invention with water can be determined, for example, by automatically contacting the fiber taken out from the nonwoven fabric left in a room at room temperature of 20° C. and relative humidity of 65% for 24 hours or more, equipped with an ink-jet type water droplet ejection unit. It is obtained by measuring the angle formed by the air interface of the droplet and the fiber when a very small amount (15 pL) of water droplet is applied to the fiber surface using a goniometer.
  • the fibers forming one surface (A) and the fibers forming the other surface (B) may have the same or different thermoplastic resins forming the fibers or different cross sections.
  • One surface (A) of the spunbond nonwoven fabric of the present invention is composed of fibers made of the above thermoplastic resin.
  • the spunbonded nonwoven fabric of the present invention preferably consists of long fibers as usual, and the constituent fibers of the one surface (A) are preferably long fibers. This is because it is easy to achieve both high productivity and excellent mechanical properties by using long fibers.
  • the average single fiber diameter (Da) of the fibers forming the one surface (A) is preferably 3.0 to 30.0 ⁇ m.
  • the average single fiber diameter (Da) of the fibers constituting the one surface (A) is preferably 3.0 ⁇ m or more, more preferably 5.0 ⁇ m or more, and still more preferably 10.0 ⁇ m or more.
  • the average single fiber diameter (Da) of the fibers forming the one surface (A) is preferably 30.0 ⁇ m or less, more preferably 28.0 ⁇ m or less, and even more preferably 25.0 ⁇ m or less.
  • the average single fiber diameter (Da) referred to in the present invention is obtained as follows.
  • an image of the cross section of the fiber constituting the one surface (A) is taken with a scanning electron microscope (SEM) at a magnification that enables observation of one single fiber.
  • SEM scanning electron microscope
  • the area Af ( ⁇ m 2 ) formed by the cross-sectional contour of the single fiber is measured using image analysis software (“WinROOF2015” manufactured by Mitani Shoji Co., Ltd.), and is the same as this area Af. Calculate the diameter of a perfect circle that is the area of .
  • the other surface (B) of the spunbond nonwoven fabric of the present invention is composed of fibers made of the above thermoplastic resin, like the one surface (A).
  • the spunbonded nonwoven fabric of the present invention is preferably made of long fibers as usual, and the constituent fibers of the other surface (B) are preferably long fibers like the surface (A). This is because it is easy to achieve both high productivity and excellent mechanical properties by using long fibers.
  • the average single fiber diameter (Db) of the fibers forming the other surface (B) is preferably 1.0 to 25.0 ⁇ m.
  • the average single fiber diameter (Db) of the fibers forming the other surface (B) is preferably 1.0 ⁇ m or more, more preferably 3.0 ⁇ m or more, and still more preferably 5.0 ⁇ m or more. This is because when the fiber is 1.0 ⁇ m or more, the arrangement of the fibers is not too dense, and when used as a material for a paper diaper, moisture easily migrates to the adjacent water absorbent body.
  • the average single fiber diameter (Db) of the fibers constituting the other surface (B) is preferably 25.0 ⁇ m or less, more preferably 20.0 ⁇ m or less, and even more preferably 16.0 ⁇ m or less. This is because when the thickness is 25.0 ⁇ m or less, a high capillary force can be easily obtained, resulting in excellent water absorption.
  • the ratio of the average single fiber diameter (Da) of the fibers constituting the one surface (A) to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more.
  • the average single fiber diameter ratio here means the average single fiber diameter (Da) of the fibers constituting the one surface (A) and the fibers constituting the other surface (B) using the above-described method.
  • the average single fiber diameter (Db) is measured, the ratio (Da/Db) is calculated, and the value is rounded to the second decimal place.
  • the size of voids between fibers varies depending on the average single fiber diameter of the constituent fibers. Therefore, when layers with different average single fiber diameters are formed, layers with different interfiber void sizes are formed. Absorbed moisture can be transferred to a layer of fine fibers. Furthermore, the inventors have found that by setting the average single fiber diameter ratio within a specific range, not only is the effect of improving water absorption due to the difference in capillary effect, but also dryness is imparted to the surface of the nonwoven fabric layer made of thick fibers.
  • the average single fiber diameter ratio (Da/Db) is preferably 1.2 or more, more preferably 1.3 or more, and even more preferably 1.4 or more.
  • the average single fiber diameter ratio (Da/Db) is preferably 1.2 or more, more preferably 1.3 or more, and even more preferably 1.4 or more.
  • the upper limit of the average single fiber diameter ratio in the present invention is not particularly limited, it is preferably 10.0 or less from the viewpoint of process stability and productivity.
  • the spunbond nonwoven fabric of the present invention has a fused portion and a non-fused portion.
  • the fused portion is a portion where the fibers forming the one surface (A) and the fibers forming the other surface (B) are fused, and are referred to as non-fused portions.
  • a portion of the spunbond nonwoven fabric is a fused portion, that is, the fibers constituting the one surface (A) and the fibers constituting the other surface (B)
  • the cross section of the spunbond nonwoven fabric is observed with a scanning electron microscope at a magnification that allows the thickness direction of the spunbond nonwoven fabric to enter the field of view. If the other surface (B) is fused at the same position in the plane direction for the selected portion where the one surface (A) is fused, the location is determined to be the fused portion. do.
  • the fiber density is high around the fused portion.
  • the water absorbed in the relatively low-density non-fused portion can be guided to the periphery of the relatively high-density fused portion by the capillary force difference, and the water moves in the plane direction. will be able to
  • the fused parts into a specific form and arrangement, the movement of water in the surface direction using the fused parts can be made more remarkable, and particularly excellent quick-drying can be achieved. That is, by controlling the form and arrangement of the fused portions, the water introduced to the periphery of a certain fused portion can also be transferred to other fused portions. Since it diffuses inside, the dryness can be expressed more efficiently than the simple movement of water in the thickness direction, and excellent quick-drying can be achieved.
  • the diameter of the minimum inscribed circle of the non-fused portion is 1.0 mm or less, and the diameter of the maximum inscribed circle of the non-fused portion is 2.0 mm or more. be.
  • the non-fused portion surrounded by the fused portion 11 can be observed with a microscope at a depth of 10 mm. A field of view with a size of ⁇ 10 mm or more is photographed. Subsequently, using the photographed image, the diameters of the minimum inscribed circle 13 and the maximum inscribed circle 14 that can be placed on the non-fused portion 12 were determined using image analysis software ("WinROOF2015" manufactured by Mitani Shoji Co., Ltd.). Measure.
  • the diameter of the minimum inscribed circle is preferably 0.8 mm or less.
  • the minimum inscribed circle has a diameter of 0.2 mm or more. If the lower limit of the diameter of the minimum inscribed circle is within the above preferable range, the fused portions are prevented from coming too close to each other, and moisture can easily pass between the fused points.
  • the larger the diameter of the maximum inscribed circle the easier it is to form a low-density portion at a location sufficiently distant from the fused location.
  • the diameter of the maximum inscribed circle of the non-fused portion is less than 2.0 mm, the coarseness and fineness of the fiber density will not be clarified, water will be difficult to be conveyed to the fused portion, and the water absorption rate will be high. cannot be expected.
  • the diameter of the maximum inscribed circle is preferably 3.0 mm or more.
  • the diameter of the maximum inscribed circle is preferably 10.0 mm or less. If the upper limit of the diameter of the maximum inscribed circle is set within the above preferable range, the fused portions are prevented from being excessively separated from each other, making it difficult for moisture to remain.
  • the fused portions are arranged in rows.
  • FIG. 2 when the surface of the spunbond nonwoven fabric 2 is observed from above, a field of view of 10 mm ⁇ 10 mm or more in which 10 or more fused parts 21 can be observed is photographed with a microscope. Subsequently, using the captured image, image analysis software (National Institutes of Health "ImageJ") was used to perform image binarization, and geometric center of gravity. A fused portion having a center-of-gravity distance closest to the center of gravity of the fused portion 21 is defined as a fused portion 22 . Next, excluding the fused portion 21, the fused portion having the closest center-of-gravity distance to the fused portion 22 is defined as the fused portion 23.
  • FIG. 1 A fused portion having a center-of-gravity distance closest to the center of gravity of the fused portion 21 is defined as a fused portion 22 .
  • the fused portion having the closest center-of-gravity distance to the fused portion 23 is defined as the fused portion 24.
  • the center of gravity of each of the fused portions 21 to 24 determined in the above steps is M21 to M24, a straight line L12 connecting M21 and M22, a straight line L23 connecting M22 and M23, and a straight line connecting M23 and M24.
  • Pull L34 The acute angles formed by L12 and L23 and L34 are measured and defined as ⁇ 1 and ⁇ 2. At this time, when each of ⁇ 1 and ⁇ 2 is 30° or less, it is in a state of being arranged in a row as defined in the present invention.
  • the adjacent fused portions are not arranged linearly, and the gap between the fused portions is not linear.
  • the improvement of the water transfer efficiency cannot be expected, and the in-plane diffusion of water cannot be promoted.
  • the fused portions are intermittently arranged.
  • M21 to M25 are determined in the same manner as described above.
  • the distance between M21 and M22 (D12), the distance between M22 and M23 (D23), the distance between M23 and M24 (D34), and the distance between M24 and M25 (D45) are measured in units of mm, Round off to the second decimal place.
  • intermittently arranging the fused portions in this way is preferable because moisture can move farther without interruption of moisture transfer between the fused portions.
  • the irregularity of the fused portion is 1.1 or more.
  • the degree of irregularity of the fused portion is obtained as follows.
  • the surface of the spunbond nonwoven fabric is observed from above, it is photographed with a microscope at a magnification that allows three or more fused parts to be observed. Subsequently, using the captured image, the image is binarized using image analysis software (“ImageJ” described above).
  • ImageJ image analysis software
  • the diameter of the maximum inscribed circle that inscribes the fused portion and the diameter of the minimum circumscribed circle that circumscribes the fused portion are measured in mm, and the minimum circumscribed circle diameter/maximum inscribed circle diameter is obtained. Calculate the circle diameter value. This is measured at 20 arbitrarily selected fused portions, a simple numerical average is calculated, and the value rounded to the second decimal place is defined as the irregularity of the fused portion referred to in the present invention.
  • the irregularity of the fused portion is less than 1.1, the outline of the fused portion will not be sufficiently long, and the high-density region around the fused portion will not expand. You can't improve your ability to withdraw. It is preferably 1.5 or more, more preferably 1.7 or more. On the other hand, it is preferable to set the fused portion irregularity to 10.0 or less. By setting the upper limit of the irregularity of the fused portion within the above preferred range, the spunbond nonwoven fabric can maintain a good feel.
  • the ratio (Tm/T) between the thickness (Tm) of the spunbond nonwoven fabric and the thickness (T) of the spunbond nonwoven fabric at the fused portion is 0.30 or less.
  • the thickness T ( ⁇ m) of the spunbond nonwoven fabric in the present invention is measured by a shape measuring machine (for example, “VR3000” manufactured by Keyence Corporation), and the thickness without load is measured for any 10 samples. It is a value obtained by measuring in ⁇ m, obtaining a simple number average, and rounding off to the first decimal place.
  • a shape measuring machine for example, “VR3000” manufactured by Keyence Corporation
  • the thickness Tm ( ⁇ m) of the fused portion is obtained as follows.
  • an image of a cross section perpendicular to the machine direction of the spunbond nonwoven fabric is taken with a scanning electron microscope (SEM) at a magnification that allows observation of the thickness of the spunbond nonwoven fabric.
  • SEM scanning electron microscope
  • the thickness (unit: ⁇ m) of the fused portion is measured.
  • the thickness Tm ( ⁇ m) of the fused portion is obtained by calculating a simple numerical average of the results obtained by performing the same operation at ten different locations and rounding off to the first decimal place.
  • T and Tm measured by the above operation calculate the value of Tm/T, and calculate the value rounded to the third decimal place.
  • the fiber density around the fused portion can be sufficiently increased. It cannot improve its ability to draw water.
  • Tm/T is preferably 0.25 or less, more preferably 0.20 or less.
  • Tm/T is preferably 0.01 or more.
  • the area ratio of the fused portion is 5% or more. If the area ratio of the fused portion is set within the range, the fused portion is sufficiently present, and moisture is less likely to remain in the non-fused portion. On the other hand, the area ratio is preferably 30% or less. When the upper limit of the area ratio is set within the above preferred range, the feel of the nonwoven fabric is not impaired.
  • the fused portion forms a concave portion facing the other surface (B) on the one surface (A).
  • the fused portion does not form a concave portion facing the other surface (B)
  • the inter-fiber gaps on the surface (A) composed of fibers having a relatively large fiber diameter The size cannot be expanded, the density difference between the front and back surfaces cannot be increased, and the dryness cannot be improved.
  • both the one surface (A) and the other surface (B) of the spunbond nonwoven fabric have contact angles with water of 30° or less. It is more preferably 20° or less, still more preferably 10° or less.
  • the contact angle with water is within the above preferable range, the nonwoven fabric easily absorbs water that contacts the surface of the spunbond nonwoven fabric.
  • the lower limit of the contact angle with water in the present invention is 0°, and the 0° contact angle with water means that all the water is absorbed by the nonwoven fabric in the measurement method described later.
  • the contact angle with water on the surface of the spunbonded nonwoven fabric can be controlled by the hydrophilicity of the thermoplastic resin used for the fibers that make up the spunbonded nonwoven fabric or by applying a hydrophilic oil in a post-process.
  • the contact angle with water tends to decrease as the hydrophilicity of the thermoplastic resin increases and as the amount of hydrophilic oil applied increases.
  • the contact angle with water on the surface of the spunbond nonwoven fabric in the present invention refers to a value calculated by measuring by the following method.
  • a droplet of 2 ⁇ L made of ion-exchanged water is prepared on the tip of the needle and applied to the nonwoven fabric.
  • the spunbond nonwoven fabric of the present invention preferably has a water absorption rate of 20 seconds or less as measured on the one surface (A).
  • the water absorption rate preferably 20 seconds or less, more preferably 15 seconds or less, and even more preferably 10 seconds or less, the nonwoven fabric has good performance in removing moisture adhering to the surface, that is, excellent water absorption.
  • the water absorption rate referred to here is measured based on "7.1.1 Dropping method” of JIS L 1907:2010 "Water absorption test method for textile products”. Drop one drop of water onto the spunbond nonwoven fabric, measure the time it takes for the specular reflection on the surface to disappear after being absorbed, and calculate the simple average of the values measured at 10 different points. The value obtained by rounding off the first place is defined as the water absorption speed referred to in the present invention.
  • the spunbond nonwoven fabric of the present invention preferably has a basis weight of 10 to 100 g/m 2 .
  • the basis weight By setting the basis weight to preferably 10 g/m 2 or more, more preferably 13 g/m 2 or more, and even more preferably 15 g/m 2 or more, it is possible to obtain a spunbond nonwoven fabric with mechanical strength suitable for practical use.
  • the basis weight By setting the basis weight to preferably 100 g/m 2 or less, more preferably 50 g/m 2 or less, a spunbonded nonwoven fabric having moderate flexibility suitable for use as a nonwoven fabric for sanitary materials can be obtained. .
  • the basis weight (g/m 2 ) of the spunbond nonwoven fabric in the present invention is a 20 cm ⁇ 25 cm test piece based on "6.2 Mass per unit area" of JIS L 1913:2010 "General nonwoven fabric test method”. 3 samples are sampled per 1 m width of the sample, the mass (g) of each sample is weighed under standard conditions, and the mass per 1 m 2 is calculated from the average value.
  • the layer (S) of the spunbonded nonwoven fabric and the layer (M) of the meltblown nonwoven fabric can be laminated according to the purpose, as long as the effects of the present invention are not impaired.
  • these stacking arrangements include aspects such as SMS, SMMS, SSMMS, and SMSMS.
  • one surface of the laminated nonwoven fabric is regarded as the surface (A) of the spunbond nonwoven fabric, and the other surface is regarded as the surface (B).
  • the spunbonded nonwoven fabric of the present invention may be provided with a hydrophilizing agent for the purpose of increasing the water absorption.
  • hydrophilizing agents include surfactants, among which nonionic surfactants are preferred.
  • the spunbond nonwoven fabric of the present invention is produced by melting a thermoplastic resin as a raw material, spinning it from a spinneret, and then cooling and solidifying the yarn obtained by cooling and solidifying it. It is produced by a spunbond process, which requires a step of heat-sealing after collection to form a nonwoven fibrous web.
  • Various shapes such as round and rectangular can be adopted as the shape of the spinneret and ejector to be used.
  • the spinning temperature is preferably (the melting temperature of the raw material thermoplastic resin + 10°C) or more and (the melting temperature of the raw material thermoplastic resin + 100°C) or less.
  • the spun yarn is then cooled.
  • Methods for cooling the spun yarn include, for example, a method of forcibly blowing cold air onto the yarn, and natural cooling at the ambient temperature around the yarn. and a method of adjusting the distance between the spinneret and the ejector, or a method of combining these methods. Also, the cooling conditions can be appropriately adjusted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the ambient temperature, and the like.
  • the cooled and solidified yarn is pulled and stretched by compressed air jetted from the ejector.
  • the spunbond nonwoven fabric of the present invention it is important to control the average single fiber diameter of the fibers constituting the one surface (A) and the other surface (B).
  • the average single fiber diameter of the fiber is determined by the discharge amount per discharge hole of the spinneret and the drawing speed, that is, the spinning speed. Therefore, it is preferable to determine the discharge rate and the spinning speed according to the desired average single fiber diameter.
  • the spinning speed is preferably 2,000 m/min or more, more preferably 3,000 m/min or more. By setting the spinning speed to 2,000 m/min or more, high productivity can be obtained, and the orientation and crystallization of the fibers can be advanced to obtain long fibers with high strength.
  • the long fiber yarn drawn by pulling in this way is collected by a moving net to be formed into a sheet, and then subjected to a heat-sealing process.
  • the spunbond nonwoven fabric of the present invention has the one surface (A) and the other surface (B) having different fiber diameters of constituent fibers.
  • a collection net is placed on the fiber web obtained by collection on the collection net as described above from the spinneret for the one surface (A).
  • a method of depositing a fibrous web from the spinneret for the other surface (B) arranged downstream of the above, heat-sealing them all at once, and fixing them can be adopted.
  • the second nonwoven fabric layer is formed by the spunbond method.
  • the nonwoven webs constituting the are superimposed offline, and a method of laminating and integrating by thermocompression bonding or the like can be adopted.
  • a preferred embodiment is a method in which the nonwoven web obtained by collecting the thermoplastic resin fibers constituting the other surface (B) by the method is continuously collected in-line and laminated and integrated by heat bonding.
  • thermocompression bonding As a method for laminating and integrating the spunbond nonwoven fabric of the present invention by thermal bonding, a thermal embossing roll having a pair of upper and lower rolls each having an engraving (concavo-convex portion) on its surface, and a roll having a flat (smooth) surface on one roll.
  • a method of heat bonding using various rolls such as a heat embossing roll that is combined with a roll with engraving (unevenness) on the surface of the other roll, and a heat calender roll that is a combination of a pair of upper and lower flat (smooth) rolls.
  • a method using thermocompression bonding such as ultrasonic bonding in which thermal bonding is performed by ultrasonic vibration of a horn can be adopted.
  • the spunbond nonwoven fabric of the present invention is produced by heat-sealing with an embossing roll
  • the one surface (A) and the other surface (B) are bonded at positions corresponding to the convex portions of the embossing roll. It is preferable because the fibers constituting the are easily fused together.
  • the line pressure applied to the spunbond between the rolls is set to 50 N/cm or more to sufficiently densify the periphery of the fused portion. preferred because it can be done. More preferably, it is 100 N/cm.
  • the surface temperature of the embossing roll should be (the melting temperature of the raw material thermoplastic resin -80 ° C.) or higher (the melting temperature of the raw material thermoplastic resin - 10° C.) or less.
  • the spunbond nonwoven fabric of the present invention it is preferable to process the one surface (A) side as a heat embossed roll with engraving and the other surface (B) side as a flat roll.
  • a hydrophilizing agent may be added to the spunbonded nonwoven fabric thus obtained before winding.
  • Examples of the method for applying the hydrophilizing agent to the spunbond nonwoven fabric include application by a kiss roll, spray, and dip coating, but application by a kiss roll is preferable from the viewpoint of uniformity and ease of control of the amount of adhesion.
  • Fabric weight was measured based on "6.2 Mass per unit area” of JIS L 1913:2010 "General nonwoven fabric test methods”.
  • Ratio of thickness of fused portion to thickness of spunbond nonwoven fabric (Tm/T) The thickness of the spunbond nonwoven fabric was measured as described above using a 3D shape measuring machine "VR-3050" manufactured by Keyence Corporation.
  • Procedure 1 Cut out a 5 cm x 5 cm sample from the spunbond nonwoven fabric.
  • Procedure 2 Two sheets of 5 cm x 5 cm cut out from JIS P 3801 type 2 filter paper are prepared for each measurement, and the mass of each sheet is measured.
  • Procedure 3 Drop 0.250 ⁇ 0.005 mL of physiological saline onto a polypropylene film. At this time, the mass of the physiological saline to be dripped is measured.
  • Procedure 4 A spunbonded nonwoven fabric is placed on top of the dropped physiological saline with the one surface (A) facing downward, and held for 1 minute.
  • Step 5 After holding the step 4, remove the spunbond nonwoven fabric from the polypropylene film, place it on the first filter paper with the one surface (A) facing up, and then place the filter paper on top of it. Put the second one on quickly.
  • Step 6 Place a weight of 125 g on the second filter paper so that the pressure is 5 g/cm 2 and hold for 1 minute.
  • Step 7 After holding in step 6 above, the weight is removed, the mass of each filter paper is measured, and the increase in mass of each filter paper is calculated.
  • Step 8 Calculate the water distribution ratio of each surface of the spunbond nonwoven fabric from the following formula.
  • Water distribution ratio (%) 100 x W1/W0
  • W0 Mass (g) of physiological saline dripped in the above procedure 3
  • W1 Mass increase (g) of the filter paper applied to the surface (A) in the procedure 7 above. The above operation was performed for 10 different samples, a simple number average was calculated, and the value rounded to the first decimal place was used as the water distribution ratio. Based on the obtained water distribution ratio, evaluation was made in the following four stages.
  • Water distribution ratio less than 20% 3 Water distribution ratio 20% or more and less than 30% 2: Water distribution ratio 30% or more and less than 40% 1: Water distribution ratio 40% or more.
  • the surface is smooth and does not feel moisture. 3: The surface is moist although there is no moisture. 1: The surface is moist and moist.
  • Example 1 Fibrous web forming one surface (A)
  • Polypropylene (PP) was melted in an extruder and spun out from a rectangular spinneret having a round hole with a hole diameter of ⁇ of 0.4 mm at a single hole discharge rate of 0.8 g/min. After the spun yarn was cooled and solidified, it was drawn and stretched by compressed air in a rectangular ejector at a pressure of 0.08 MPa, and collected on a moving net to obtain a nonwoven fiber web. .
  • the average single fiber diameter of the fibers constituting one surface (A) obtained was 20.4 ⁇ m.
  • the laminated fiber web obtained in this way was placed on the upper roll, as shown in pattern 1 in FIG.
  • the upper roll side is the fiber web forming one surface (A)
  • the lower roll side is the other
  • a fibrous web forming the surface (B) was heat-sealed at a linear pressure of 200 N/cm and a heat-sealing temperature of 130° C. to obtain a spunbond nonwoven fabric having a basis weight of 40 g/m 2 .
  • a nonionic surfactant was applied to the nonwoven fabric using a kiss roll so that the active ingredient was 0.5 wt% with respect to the weight of the spunbond nonwoven fabric.
  • Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 2 As shown in pattern 2 in FIG. 3-2, the upper roll uses a metal embossing roll with a lattice pattern in which linear arrays formed by obliquely aligning rectangular protrusions are arranged orthogonally. A spunbond nonwoven fabric was obtained in the same manner as in Example 1.
  • Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 3 On the upper roll, as shown in pattern 3 in Fig. 3-3, a metal embossing roll with a pattern in which linear arrays formed by rectangular protrusions are arranged in parallel and some intervals are wide A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that it was used.
  • Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 4 On the upper roll, as shown in pattern 4 in FIG. 3-4, linear arrays formed by rectangular protrusions are arranged orthogonally, and the distance between the protrusions forming the straight lines is closer than that of pattern 1.
  • a spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that a patterned metal embossing roll was used.
  • Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 5 Example 1 except that a nonionic surfactant was applied to the nonwoven fabric by spraying only on the other surface (B) so that the active ingredient was 0.3 wt% with respect to the weight of the spunbond nonwoven fabric as a hydrophilic treatment.
  • a spunbond nonwoven fabric was obtained in the same manner as
  • Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 1 A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that instead of heat-sealing using an embossing roll, the obtained fiber web was heat-sealed with hot air at 150°C.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 3 A spunbond nonwoven fabric was obtained in the same manner as in Example 1 except that the upper roll side was a fiber web forming the other surface (B) and the lower roll side was thermally bonded as a fiber web forming one surface (A). rice field.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • the upper roll is a metal embossing roll in which linear arrays formed by rectangular protrusions are arranged in parallel at intervals of 2 mm.
  • a spunbond nonwoven fabric was obtained in the same manner as in 1.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 6 For the upper roll, as shown in pattern 7 in FIG. A spunbond nonwoven fabric was obtained in the same manner as in Example 1.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 7 As shown in pattern 8 in FIG. 4-4, the same as in Example 1 except that a metal embossing roll with the same arrangement as pattern 1 except that the shape of the convex part is a perfect circle was used for the upper roll. A spunbond nonwoven fabric was obtained by the method of.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Example 8 A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that an embossing roll was used and heat-sealed at a linear pressure of 10 N/cm.
  • Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
  • Examples 1 to 5 have a large average single fiber diameter ratio (Da/Db) and have locations where the fibers on one surface (A) and the fibers on the other surface (B) are fused together. Moreover, since the fused portion is controlled to have a specific shape and arrangement, it is found to have excellent dryness and quick drying properties.
  • Da/Db average single fiber diameter ratio
  • Comparative Example 1 since there is no place where the fibers on one surface (A) and the fibers on the other surface (B) are fused together, it is difficult for water to move in the plane, Poor dryness and fast drying.
  • Comparative Example 2 since the average single fiber diameter ratio is small, moisture is not transferred to the other surface (B) side in the nonwoven fabric, and the dryness and quick drying properties are poor.
  • Comparative Example 3 since the fused portion was formed from the surface (B) side to the one surface (A) side, the void size between the fibers on the other surface (B) side was expanded, so that the moisture inside the nonwoven fabric was reduced to the other side. It was difficult to migrate to the surface (B) side of , and was inferior in dryness and quick drying properties.
  • Comparative Example 4 since the diameter of the minimum inscribed circle of the non-fused portion is large, the movement of water between the fused portions is weak, and diffusion of water within the surface is difficult to occur, resulting in poor quick-drying properties. Further, in Comparative Example 5, since the maximum inscribed circle diameter is small, water tends to remain in the non-fused portion, resulting in poor quick-drying properties. In Comparative Example 6, since the fused portion is not linearly connected, water cannot diffuse in the plane, resulting in poor quick-drying properties. In addition, in Comparative Example 7, since the degree of irregularity of the fused portions is small, water movement between the fused portions is weak, and diffusion of water within the surface is difficult to occur, resulting in poor quick-drying properties. Met.
  • the spunbond nonwoven fabric of the present invention can be suitably used as a sanitary material.
  • the sanitary material of the present invention provides excellent water absorption, dryness and quick drying properties.
  • the sanitary material of the present invention is mainly a disposable article used for health-related purposes such as medical care and nursing care, and includes disposable diapers, sanitary napkins, gauze, bandages, masks, gloves, adhesive bandages, etc. Its constituent members, for example, the top sheet, back sheet, side gathers, etc. of disposable diapers are also included. Among them, the following aspects are mentioned as preferable aspects.
  • a first preferred embodiment is a diaper in which the topsheet is composed of the above spunbond nonwoven fabric.
  • the spunbond nonwoven fabric when used so that the one surface (A) is placed as the skin surface side of the top sheet of the diaper, it quickly absorbs excreted urine and the other surface (A) Since the liquid is quickly transferred to B), the surface of the spunbond nonwoven fabric can be kept dry.
  • a second preferred embodiment is a diaper in which a part of the waist portion is made of the spunbond nonwoven fabric.
  • the spunbond nonwoven fabric when used so that the one surface (A) is placed as the skin side of the top sheet waist portion of the diaper, it quickly absorbs sweat and the other surface (B ), the surface of the spunbond nonwoven fabric can be kept dry.
  • a third preferred embodiment is a mask in which the inner surface layer is composed of the above spunbond nonwoven fabric.
  • the term "inner layer” as used in the present invention refers to the layer of the face piece covering the mouth that is located closest to the mouth.

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Abstract

This spunbonded nonwoven fabric has fused parts and non-fused parts. The fused parts form parts recessed in one surface (A) toward another surface (B). The ratio (Da/Db) of the average single-fiber diameter (Da) of the fibers constituting the one surface (A) to the average single-fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or greater. The spunbonded nonwoven fabric satisfies the conditions stated herein.　(1) The diameters of the minimum inscribed circles of the non-fused parts are 1.0 mm or less; (2) the diameters of the maximum inscribed circles of the non-fused parts are 2.0 mm or greater; (3) the fused parts are disposed continuously in a row configuration; (4) the ratio (Tm/T) of the thickness (Tm) of the spunbonded nonwoven fabric at the fused parts to the thickness (T) of the spunbonded nonwoven fabric is 0.30 or less; and (5) the degrees of deformation of the fused parts are 1.1 or greater.　Provided is a spunbonded nonwoven fabric that has sufficient absorbency and dryness to maintain comfort within a member using a sanitary nonwoven fabric, and has an excellent quick-drying property.

Description

スパンボンド不織布および衛生材料Spunbond nonwovens and sanitary materials
　本発明は、ドライ性および速乾性に優れ、特に衛生材料用途に好適なスパンボンド不織布およびこれを使用した衛生材料に関するものである。 The present invention relates to a spunbond nonwoven fabric that is excellent in dryness and quick-drying properties and is particularly suitable for use as sanitary materials, and sanitary materials using the same.
　一般に紙おむつや生理用ナプキン、マスク等の衛生材料においては、尿や汗などの水分を素早く取り除き、肌に触れる表面をドライに保つことが快適性への鍵となる。 In general, for sanitary materials such as disposable diapers, sanitary napkins, and masks, the key to comfort is to quickly remove moisture such as urine and sweat and keep the surface that touches the skin dry.
　このため、直接肌に触れる部材においては、水分を素早く吸収する吸水性と、吸収した水分を最表面層から移行させ、表面をドライな状態にするドライ性の両立が要求される。さらに、上記の水分移動は素早く行われることが肝心であり、いわゆる速乾性も重要となる。 For this reason, members that come into direct contact with the skin are required to have both water absorbency, which absorbs water quickly, and dryness, which allows the absorbed water to migrate from the outermost layer and keep the surface dry. Furthermore, it is essential that the above-mentioned moisture transfer be carried out quickly, and so-called quick-drying is also important.
　従来、この表面部材には、親水化処理を施した各種不織布が広く使用されてきた。これらは、最表面層から内層の不織布や吸収体へ水分を誘導できるものの、最表面層に水分が残存しやすく、ドライ性に劣るものであった。 Conventionally, various types of non-woven fabrics that have undergone hydrophilic treatment have been widely used for this surface member. Although these can induce moisture from the outermost layer to the inner nonwoven fabric or absorber, moisture tends to remain in the outermost layer, resulting in poor dryness.
　この課題に対して、特許文献１では、細繊度繊維からなる繊維層（肌面側）と、太繊度繊維からなる繊維層が積層され、境界面で一部が交絡した不織布が提案されている。また、特許文献２では、複数の繊維の混率と繊維径の差により平均繊維非占有空隙が異なるシートを積層させ、肌に触れる第１層の平均繊維非占有空隙を第１層以外の層よりも大きくしたシートが提案されている。 In response to this problem, Patent Document 1 proposes a nonwoven fabric in which a fiber layer (skin surface side) made of fine fineness fibers and a fiber layer made of large fineness fibers are laminated and partially entangled at the interface. . In addition, in Patent Document 2, sheets having different average non-fiber-occupied voids are laminated according to the difference in the mixing ratio and fiber diameter of a plurality of fibers, and the average non-fiber-occupied voids of the first layer that comes in contact with the skin are reduced from the layers other than the first layer. A sheet with a larger diameter is also proposed.
特開平７－０４２０５７号公報JP-A-7-042057 特開平７－１７８１３３号公報JP-A-7-178133
　しかしながら、特許文献１の技術では、肌面側の細繊度繊維からなる繊維層がそれ以外の層に対して緻密な構造となるため、肌面側の繊維層に水分が残存しやすく、ドライ性を得ることが困難である。さらに、肌面側の緻密な繊維層のため透液性が低下し、水分を迅速に吸収することができず、吸水性を得ることが困難である。 However, in the technique of Patent Document 1, the fiber layer made of fine fibers on the skin side has a denser structure than the other layers, so moisture tends to remain in the fiber layer on the skin side, resulting in dryness. is difficult to obtain. Furthermore, the dense fiber layer on the skin side reduces the liquid permeability, making it impossible to rapidly absorb water, making it difficult to obtain water absorbency.
　一方、特許文献２の技術では、層間で平均繊維非占有空隙に差を設けることで、毛細管作用により、第１層で吸収した水分を第２層（肌面と逆の層）に誘導することが可能であると記載されている。しかしながら、肌面層側の特許文献２が開示している平均繊維非占有空隙は繊維が占める空間を除く空間の総体積を示すため、毛細管力に重要である繊維間の空隙のサイズを示す指標ではなく、層間で差があるからといって毛細管力に差が生じることにはならない。 On the other hand, in the technique of Patent Document 2, by providing a difference in average non-fiber-occupied voids between layers, moisture absorbed in the first layer is guided to the second layer (the layer opposite to the skin surface) by capillary action. is stated to be possible. However, the average non-fiber-occupied voids disclosed in Patent Document 2 on the skin layer side indicates the total volume of the space excluding the space occupied by the fibers. However, the fact that there is a difference between the layers does not mean that there is a difference in capillary force.
　さらに、表裏の毛細管力差が作用したとしても、水分が不織布面内で拡散しにくいため、吸水量の増加に伴って非肌面層の毛細管力が徐々に低下し、肌面からの水分の移行は限定的な効果となるため、ドライ性および速乾性は不十分なものである。 Furthermore, even if there is a difference in capillary force between the front and back surfaces, it is difficult for moisture to diffuse within the surface of the non-woven fabric, so as the amount of water absorption increases, the capillary force of the non-skin layer gradually decreases, and moisture from the skin surface is removed. Dryness and fast drying are unsatisfactory as migration is of limited effectiveness.
　そこで、本発明の目的は、上記の事情に鑑みてなされたものであって、衛材用不織布を用いた部材内の快適性を保つために十分な吸水性およびドライ性を有し、かつ速乾性に優れたスパンボンド不織布を提供することである。 Therefore, the object of the present invention has been made in view of the above circumstances. To provide a spunbond nonwoven fabric excellent in drying property.
　上記課題を解決するため本発明のスパンボンド不織布は、次の構成を有する。すなわち、
融着部と非融着部とを有し、一方の表面（Ａ）において、融着部が他方の表面（Ｂ）に向かう凹部を形成しており、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）の、前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）に対する比（Ｄａ／Ｄｂ）が１．１以上であって、以下の条件を満たすスパンボンド不織布、である。 In order to solve the above problems, the spunbond nonwoven fabric of the present invention has the following constitution. i.e.
It has a fused portion and a non-fused portion, and on one surface (A), the fused portion forms a recess facing the other surface (B), and constitutes the one surface (A). The ratio (Da/Db) of the average single fiber diameter (Da) of the fibers to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more, and the following conditions are satisfied: is a spunbond nonwoven, which satisfies.
　(1)前記非融着部の最小内接円の直径が１．０ｍｍ以下である
　(2)前記非融着部の最大内接円の直径が２．０ｍｍ以上である
　(3)前記融着部が列状に連なって配置されている
　(4)前記融着部におけるスパンボンド不織布の厚み（Ｔｍ）とスパンボンド不織布の厚み（Ｔ）との比（Ｔｍ／Ｔ）が、０．３０以下である
　(5)前記融着部の異形度が１．１以上である。 (1) The diameter of the minimum inscribed circle of the unfused portion is 1.0 mm or less (2) The diameter of the maximum inscribed circle of the unfused portion is 2.0 mm or more (3) The fused portion (4) The ratio (Tm/T) of the thickness (Tm) of the spunbond nonwoven fabric to the thickness (T) of the spunbond nonwoven fabric in the fused portion is 0.30 or less. (5) The fused portion has an irregularity of 1.1 or more.
　また、本発明の衛生材料は、次の構成を有する。すなわち、
前記スパンボンド不織布で少なくとも一部が構成されてなる衛生材料、である。 Moreover, the sanitary material of the present invention has the following constitution. i.e.
A sanitary material at least partially composed of the spunbond nonwoven fabric.
　本発明のスパンボンド不織布は、前記非融着部の最大内接円の直径が１０．０ｍｍ以下であることが好ましい。 In the spunbonded nonwoven fabric of the present invention, the diameter of the maximum inscribed circle of the non-fused portion is preferably 10.0 mm or less.
　本発明のスパンボンド不織布は、前記融着部が間欠的に配置されていることが好ましい。 The spunbonded nonwoven fabric of the present invention preferably has the fused portions arranged intermittently.
　本発明のスパンボンド不織布は、前記非融着部の最小内接円の直径が０．２ｍｍ以上であることが好ましい。 In the spunbond nonwoven fabric of the present invention, it is preferable that the diameter of the minimum inscribed circle of the non-fused portion is 0.2 mm or more.
　本発明のスパンボンド不織布は、前記表面（Ａ）および表面（Ｂ）の、水との接触角がともに３０°以下であることが好ましい。 In the spunbond nonwoven fabric of the present invention, it is preferable that both the surface (A) and the surface (B) have contact angles with water of 30° or less.
　本発明の衛生材料は、おむつであることが好ましい。 The sanitary material of the present invention is preferably a diaper.
　本発明のおむつである衛生材料は、前記少なくとも一部がトップシートであることが好ましい。 In the sanitary material that is the diaper of the present invention, it is preferable that at least part of the sanitary material is a topsheet.
　本発明のおむつである衛生材料は、前記少なくとも一部がウエスト部の少なくとも一部であることが好ましい。 In the sanitary material that is the diaper of the present invention, the at least part is preferably at least part of the waist portion.
　本発明の衛生材料は、マスクであることが好ましい。 The sanitary material of the present invention is preferably a mask.
　本発明のマスクである衛生材料は、前記少なくとも一部がマスクの内面層であることが好ましい。 In the sanitary material that is the mask of the present invention, it is preferable that the at least part of the sanitary material is the inner surface layer of the mask.
　本発明によれば、衛材用不織布として用いるのに十分な吸水性およびドライ性を有し、かつ優れた速乾性を有するスパンボンド不織布を得ることができる。 According to the present invention, it is possible to obtain a spunbond nonwoven fabric that has sufficient water absorbency and dryness to be used as a nonwoven fabric for sanitary materials and has excellent quick-drying properties.
本発明のスパンボンド不織布の一実施態様における非融着部の最大内接円および、最小内接円の決定方法を例示する上面概念図である。FIG. 4 is a conceptual top view illustrating a method of determining the maximum and minimum inscribed circles of the non-fused portion in one embodiment of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の別の実施態様における非融着部の最大内接円および、最小内接円の決定方法を例示する上面概念図である。FIG. 4 is a conceptual top view illustrating a method of determining the maximum inscribed circle and the minimum inscribed circle of the non-fused portion in another embodiment of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布のさらに別の実施態様における非融着部の最大内接円および、最小内接円の決定方法を例示する上面概念図である。FIG. 4 is a top view conceptual diagram illustrating a method of determining the maximum inscribed circle and the minimum inscribed circle of the non-fused portion in still another embodiment of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の一実施態様における融着部が列状に連なって配置されているか決定する方法を例示する上面概念図である。FIG. 3 is a top conceptual view illustrating a method for determining whether the fused portions in one embodiment of the spunbond nonwoven fabric of the present invention are arranged in rows. 本発明のスパンボンド不織布の実施例１で使用したエンボスロールのパターン様態を説明する模式図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining the pattern aspect of the embossing roll used in Example 1 of the spunbond nonwoven fabric of this invention. 本発明のスパンボンド不織布の実施例２で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Example 2 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の実施例３で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Example 3 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の実施例４で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 4 is a schematic diagram illustrating the pattern of the embossing roll used in Example 4 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の比較例４で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 4 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 4 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の比較例５で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 5 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の比較例６で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 6 of the spunbond nonwoven fabric of the present invention. 本発明のスパンボンド不織布の比較例７で使用したエンボスロールのパターン様態を説明する模式図である。FIG. 3 is a schematic diagram illustrating the pattern of the embossing roll used in Comparative Example 7 of the spunbond nonwoven fabric of the present invention.
　本発明のスパンボンド不織布は、融着部と非融着部とを有し、一方の表面（Ａ）において、融着部が他方の表面（Ｂ）に向かう凹部を形成しており、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）の、前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）に対する比（Ｄａ／Ｄｂ）が１．１以上であって、以下の条件を満たす。 The spunbond nonwoven fabric of the present invention has a fused portion and a non-fused portion. The ratio (Da/Db) of the average single fiber diameter (Da) of the fibers constituting the other surface (A) to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more and satisfies the following conditions:
　(1)前記非融着部の最小内接円の直径が１．０ｍｍ以下である。 (1) The diameter of the minimum inscribed circle of the non-fused portion is 1.0 mm or less.
　(2)前記非融着部の最大内接円の直径が２．０ｍｍ以上である。 (2) The diameter of the maximum inscribed circle of the non-fused portion is 2.0 mm or more.
　(3)前記融着部が列状に連なって配置されている。 (3) The fused portions are arranged in a row.
　(4)前記融着部におけるスパンボンド不織布の厚み（Ｔｍ）とスパンボンド不織布の厚み（Ｔ）との比（Ｔｍ／Ｔ）が、０．３０以下である。 (4) The ratio (Tm/T) between the thickness (Tm) of the spunbond nonwoven fabric and the thickness (T) of the spunbond nonwoven fabric in the fused portion is 0.30 or less.
　(5)前記融着部の異形度が１．１以上である。 (5) The irregularity of the fused portion is 1.1 or more.
　以下に、その構成要素について詳細に説明するが、本発明はその要旨を超えない限り、以下に説明する範囲に何ら限定されるものではない。 The constituent elements will be described in detail below, but the present invention is not limited to the scope described below as long as it does not exceed the gist of the present invention.
　［繊維］
　まず、本発明のスパンボンド不織布を構成する繊維は、常法の通り熱可塑性樹脂からなる。熱可塑性樹脂は１種類であってもよいし、複数の熱可塑性樹脂からなるものであってもよい。 [fiber]
First, the fibers constituting the spunbonded nonwoven fabric of the present invention are made of a thermoplastic resin as usual. One type of thermoplastic resin may be used, or a plurality of thermoplastic resins may be used.
　本発明のスパンボンド不織布を構成する繊維に用いられる熱可塑性樹脂の例としては、ポリエチレンテレフタレート、ポリトリメチレンテレフタレート、ポリブチレンテレフタレート、ポリヘキサメチレンテレフタレート等の芳香族ポリエステル系ポリマーおよびその共重合体；ポリ乳酸、ポリエチレンサクシネート、ポリブチレンサクシネート、ポリブチレンサクシネートアジペート、ポリヒドロキシブチレート-ポリヒドロキシバリレート共重合体、ポリカプロラクトン等の脂肪族ポリエステル系ポリマーおよびその共重合体；ポリアミド６、ポリアミド６６、ポリアミド６１０、ポリアミド１０、ポリアミド１２、ポリアミド６－１２等の脂肪族ポリアミド系ポリマーおよびその共重合体；ポリプロピレン、ポリエチレン、ポリブテン、ポリメチルペンテン等のポリオレフィン系ポリマーおよびその共重合体、エチレン単位を２５モル％から７０モル％含有する水不溶性のエチレン－ビニルアルコール共重合体系ポリマー、ポリスチレン系、ポリジエン系、塩素系、ポリオレフィン系、ポリエステル系、ポリウレタン系、ポリアミド系、フッ素系のエラストマー系ポリマー等であり、これらの中から選んで用いることができる。また、上記のポリマーにおいては、酸化チタン、シリカ、酸化バリウムなどの無機質、カーボンブラック、染料や顔料などの着色剤、難燃剤、蛍光増白剤、酸化防止剤、あるいは紫外線吸収剤などの各種添加剤をポリマー中に含んでいてもよい。さらに、不織布の触感を良好にする観点から、炭素数が１５以上５０以下の脂肪酸アミド化合物が含有されていてもよい。さらに、汗や尿などの水分との親和性を向上する観点から、親水化剤が含有されていてもよい。 Examples of thermoplastic resins used for fibers constituting the spunbond nonwoven fabric of the present invention include aromatic polyester polymers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, and copolymers thereof; Aliphatic polyester polymers such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, polycaprolactone and copolymers thereof; polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 12, polyamide 6-12 and other aliphatic polyamide polymers and their copolymers; polypropylene, polyethylene, polybutene, polymethylpentene and other polyolefin polymers and their copolymers, ethylene units Water-insoluble ethylene-vinyl alcohol copolymer containing 25 mol% to 70 mol%, polystyrene, polydiene, chlorine, polyolefin, polyester, polyurethane, polyamide, fluorine elastomer polymer, etc. and can be selected from among them. In addition, various additives such as inorganic substances such as titanium oxide, silica, and barium oxide, carbon black, colorants such as dyes and pigments, flame retardants, fluorescent brighteners, antioxidants, and ultraviolet absorbers may be added to the above polymers. Agents may be included in the polymer. Furthermore, from the viewpoint of improving the texture of the nonwoven fabric, a fatty acid amide compound having 15 or more and 50 or less carbon atoms may be contained. Furthermore, from the viewpoint of improving affinity with water such as sweat and urine, a hydrophilizing agent may be contained.
　本発明のスパンボンド不織布を構成する繊維は、単成分繊維はもとより、２種類以上の樹脂を複合した複合繊維であってもよい。上記繊維が複合繊維の場合、本発明の効果を損ねない限り特に限定されるものではなく、芯鞘型や海島型、サイドバイサイド型、偏心芯鞘型、などから適宜選択すればよい。さらには、繊維の一部もしくは全体が一本の繊維から複数本の繊維に分割される割繊型複合繊維であってもよい。 The fibers constituting the spunbond nonwoven fabric of the present invention may be not only monocomponent fibers, but also composite fibers obtained by combining two or more types of resins. When the above fiber is a composite fiber, it is not particularly limited as long as it does not impair the effects of the present invention, and may be appropriately selected from a core-sheath type, a sea-island type, a side-by-side type, an eccentric core-sheath type, and the like. Further, it may be a split fiber type conjugate fiber in which a part or the whole of a single fiber is split into a plurality of fibers.
　本発明に係る繊維の断面形状は、本発明の効果を損ねない限り特に限定されるものではなく、丸断面はもとより、三角や扁平、六角形、中空などの異形断面であっても良い。 The cross-sectional shape of the fiber according to the present invention is not particularly limited as long as it does not impair the effects of the present invention, and may be a circular cross-section, as well as an irregular cross-section such as triangular, flat, hexagonal, or hollow.
　本発明のスパンボンド不織布を構成する繊維は、いずれも水との接触角が９０°以下であることが好ましい。繊維における水との接触角は、後述する不織布表面における水との接触角とは異なる指標であり、該接触角が９０°を超えれば疎水性、９０°以下であれば親水性となる。繊維の水との接触角が９０°以下の繊維で構成されることによって、不織布表面の水との接触角を容易に３０°以下とすることができる。 The fibers constituting the spunbond nonwoven fabric of the present invention preferably have a contact angle with water of 90° or less. The contact angle with water on the fiber is an index different from the contact angle with water on the surface of the nonwoven fabric, which will be described later. If the contact angle exceeds 90°, it is hydrophobic, and if it is 90° or less, it is hydrophilic. By using fibers having a contact angle with water of 90° or less, the contact angle with water on the surface of the nonwoven fabric can be easily reduced to 30° or less.
　なお、本発明の繊維の水との接触角は、例えば、室温２０℃、相対湿度６５％の室内に２４時間以上放置した不織布から取り出した繊維に対し、インクジェット方式水滴吐出部を搭載した自動接触角計を用いて極少量（１５ｐＬ）の水滴を繊維表面に着液させた際の、液滴の空気界面と繊維のなす角を測定することにより求められる。 The contact angle of the fiber of the present invention with water can be determined, for example, by automatically contacting the fiber taken out from the nonwoven fabric left in a room at room temperature of 20° C. and relative humidity of 65% for 24 hours or more, equipped with an ink-jet type water droplet ejection unit. It is obtained by measuring the angle formed by the air interface of the droplet and the fiber when a very small amount (15 pL) of water droplet is applied to the fiber surface using a goniometer.
　なお、一方の表面（Ａ）を構成する繊維と他方の表面（Ｂ）を構成する繊維とで、繊維を構成する熱可塑性樹脂や繊維断面が同一であっても、異なっていてもよい。 The fibers forming one surface (A) and the fibers forming the other surface (B) may have the same or different thermoplastic resins forming the fibers or different cross sections.
　［表面（Ａ）］
　本発明のスパンボンド不織布の一方の表面（Ａ）は、前記の熱可塑性樹脂からなる繊維で構成される。 [Surface (A)]
One surface (A) of the spunbond nonwoven fabric of the present invention is composed of fibers made of the above thermoplastic resin.
　本発明のスパンボンド不織布は、常法の通り、長繊維からなることが好ましく、前記一方の表面（Ａ）の構成繊維が長繊維であることが好ましい。長繊維からなることにより、高い生産性と優れた力学物性を両立しやすいためである。 The spunbonded nonwoven fabric of the present invention preferably consists of long fibers as usual, and the constituent fibers of the one surface (A) are preferably long fibers. This is because it is easy to achieve both high productivity and excellent mechanical properties by using long fibers.
　本発明において前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）は、３．０～３０．０μｍであることが好ましい。前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）は、好ましくは３．０μｍ以上、より好ましくは５．０μｍ以上、さらに好ましくは１０．０μｍ以上である。前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）を３．０μｍ以上とすることにより、衛生材料として使用した場合、隣接する吸水体に水分が移行しやすくなる。また、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）は、好ましくは３０．０μｍ以下、より好ましくは２８．０μｍ以下、さらに好ましくは２５．０μｍ以下である。前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）を３０．０μｍ以下とすることにより、ソフトな風合いを得やすい。 In the present invention, the average single fiber diameter (Da) of the fibers forming the one surface (A) is preferably 3.0 to 30.0 μm. The average single fiber diameter (Da) of the fibers constituting the one surface (A) is preferably 3.0 µm or more, more preferably 5.0 µm or more, and still more preferably 10.0 µm or more. By setting the average single fiber diameter (Da) of the fibers constituting the one surface (A) to 3.0 μm or more, when used as a sanitary material, moisture easily migrates to the adjacent absorbent. The average single fiber diameter (Da) of the fibers forming the one surface (A) is preferably 30.0 μm or less, more preferably 28.0 μm or less, and even more preferably 25.0 μm or less. By setting the average single fiber diameter (Da) of the fibers constituting the one surface (A) to 30.0 μm or less, it is easy to obtain a soft feel.
　本発明でいう平均単繊維直径（Ｄａ）は以下のようにして求めるものである。 The average single fiber diameter (Da) referred to in the present invention is obtained as follows.
　まず、前記一方の表面（Ａ）を構成する繊維の横断面を走査型電子顕微鏡（ＳＥＭ）で１本の単繊維が観察できる倍率として画像を撮影する。撮影された繊維断面画像を用い、画像解析ソフトウェア（三谷商事（株）製「ＷｉｎＲＯＯＦ２０１５」）を用いて、単繊維の断面輪郭が形成する面積Ａｆ（μｍ２）を計測し、この面積Ａｆと同一の面積となる真円の直径を算出する。これを前記一方の表面（Ａ）から任意に抽出した単繊維２０本について測定し、単純な数平均を求め、単位をμｍとして、小数点第２位を四捨五入した値を前記一方の表面（Ａ）の繊維の平均単繊維直径（Ｄａ）とする。 First, an image of the cross section of the fiber constituting the one surface (A) is taken with a scanning electron microscope (SEM) at a magnification that enables observation of one single fiber. Using the photographed fiber cross-sectional image, the area Af (μm 2 ) formed by the cross-sectional contour of the single fiber is measured using image analysis software (“WinROOF2015” manufactured by Mitani Shoji Co., Ltd.), and is the same as this area Af. Calculate the diameter of a perfect circle that is the area of . This is measured for 20 single fibers arbitrarily extracted from the one surface (A), a simple number average is obtained, the unit is μm, and the value rounded to the second decimal place is the one surface (A) is the average single fiber diameter (Da) of the fibers.
　［表面（Ｂ）］
　本発明のスパンボンド不織布の他方の表面（Ｂ）は、前記一方の表面（Ａ）と同様に、前記の熱可塑性樹脂からなる繊維で構成される。 [Surface (B)]
The other surface (B) of the spunbond nonwoven fabric of the present invention is composed of fibers made of the above thermoplastic resin, like the one surface (A).
　本発明のスパンボンド不織布は、常法の通り、長繊維からなることが好ましく、前記他方の表面（Ｂ）の構成繊維が、表面（Ａ）と同様に、長繊維であることが好ましい。長繊維からなることにより、高い生産性と優れた力学物性を両立しやすいためである。 The spunbonded nonwoven fabric of the present invention is preferably made of long fibers as usual, and the constituent fibers of the other surface (B) are preferably long fibers like the surface (A). This is because it is easy to achieve both high productivity and excellent mechanical properties by using long fibers.
　本発明において前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）は、１．０～２５．０μｍであることが好ましい。前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）は、好ましくは１．０μｍ以上、より好ましくは３．０μｍ以上、さらに好ましくは５．０μｍ以上である。１．０μｍ以上とすることにより、繊維の配置が緻密になり過ぎず、紙おむつ用材料として使用した場合、隣接する吸水体に水分が移行しやすいためである。また、前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）は、好ましくは２５．０μｍ以下、より好ましくは２０．０μｍ以下、さらに好ましくは１６．０μｍ以下である。２５．０μｍ以下とすることにより、高い毛管力を得やすく、優れた吸水性となるためである。 In the present invention, the average single fiber diameter (Db) of the fibers forming the other surface (B) is preferably 1.0 to 25.0 μm. The average single fiber diameter (Db) of the fibers forming the other surface (B) is preferably 1.0 µm or more, more preferably 3.0 µm or more, and still more preferably 5.0 µm or more. This is because when the fiber is 1.0 μm or more, the arrangement of the fibers is not too dense, and when used as a material for a paper diaper, moisture easily migrates to the adjacent water absorbent body. Also, the average single fiber diameter (Db) of the fibers constituting the other surface (B) is preferably 25.0 μm or less, more preferably 20.0 μm or less, and even more preferably 16.0 μm or less. This is because when the thickness is 25.0 μm or less, a high capillary force can be easily obtained, resulting in excellent water absorption.
　［表面（Ａ）および表面（Ｂ）の平均単繊維直径］
　本発明のスパンボンド不織布において、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）の、前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）に対する比（Ｄａ／Ｄｂ、以下、単に「平均単繊維直径比」と略することがある）がは、１．１以上である。 [Average Single Fiber Diameter of Surface (A) and Surface (B)]
In the spunbond nonwoven fabric of the present invention, the ratio of the average single fiber diameter (Da) of the fibers constituting the one surface (A) to the average single fiber diameter (Db) of the fibers constituting the other surface (B) (Da/Db, hereinafter sometimes simply abbreviated as "average single fiber diameter ratio") is 1.1 or more.
　ここでいう平均単繊維直径比とは、前述の手法を用いて、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）と、前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）を測定し、その比（Ｄａ／Ｄｂ）を算出し、小数点第２位を四捨五入した値である。 The average single fiber diameter ratio here means the average single fiber diameter (Da) of the fibers constituting the one surface (A) and the fibers constituting the other surface (B) using the above-described method. The average single fiber diameter (Db) is measured, the ratio (Da/Db) is calculated, and the value is rounded to the second decimal place.
　一般に、不織布においては、構成繊維の平均単繊維直径に応じて、繊維同士が織りなす空隙サイズが変化する。このため、平均単繊維直径が異なる層が形成した場合には繊維間空隙サイズが異なる層が形成されることとなり、水分が付着した場合には、毛管力の差により、太い繊維からなる層に吸収された水分を、細い繊維からなる層に移行させることができる。さらに、この平均単繊維直径比を特定の範囲とすることで、毛細管効果の差による吸水性向上効果のみならず、太い繊維からなる不織布層の表面にドライ性が付与されることを見出した。 In general, in non-woven fabrics, the size of voids between fibers varies depending on the average single fiber diameter of the constituent fibers. Therefore, when layers with different average single fiber diameters are formed, layers with different interfiber void sizes are formed. Absorbed moisture can be transferred to a layer of fine fibers. Furthermore, the inventors have found that by setting the average single fiber diameter ratio within a specific range, not only is the effect of improving water absorption due to the difference in capillary effect, but also dryness is imparted to the surface of the nonwoven fabric layer made of thick fibers.
　本発明において、前記平均単繊維直径比（Ｄａ／Ｄｂ）は、１．２以上が好ましく、１．３以上がより好ましく、１．４以上がさらに好ましい。平均単繊維直径比（Ｄａ／Ｄｂ）を１．１以上にすることによって、上述の毛細管効果が作用し、良好な吸水性および前記一方の表面（Ａ）におけるドライ性を得ることができる。なお、本発明における平均単繊維直径比の上限は特に制限されないが、工程安定性や生産性の観点から１０．０以下が好ましい。 In the present invention, the average single fiber diameter ratio (Da/Db) is preferably 1.2 or more, more preferably 1.3 or more, and even more preferably 1.4 or more. By setting the average single fiber diameter ratio (Da/Db) to 1.1 or more, the above-described capillary effect works, and good water absorption and dryness on the one surface (A) can be obtained. Although the upper limit of the average single fiber diameter ratio in the present invention is not particularly limited, it is preferably 10.0 or less from the viewpoint of process stability and productivity.
　［スパンボンド不織布］
　本発明のスパンボンド不織布は、融着部と非融着部を有する。ここでいう融着部とは、前記一方の表面（Ａ）を構成する繊維と前記他方の表面（Ｂ）を構成する繊維とが融着している箇所のことであり、非融着部とはスパンボンド不織布上における融着部以外の箇所であって、かつ融着部に囲まれた箇所のことである。 [Spunbond nonwoven]
The spunbond nonwoven fabric of the present invention has a fused portion and a non-fused portion. Here, the fused portion is a portion where the fibers forming the one surface (A) and the fibers forming the other surface (B) are fused, and are referred to as non-fused portions. is a portion on the spunbond nonwoven fabric other than the fused portion and surrounded by the fused portion.
　本発明において、スパンボンド不織布上のある一部分において、その箇所が融着部であるかどうか、すなわち、前記一方の表面（Ａ）を構成する繊維と、前記他方の表面（Ｂ）を構成する繊維とが融着している箇所であるかどうかは、スパンボンド不織布の当該部分の横断面を、走査型電子顕微鏡でスパンボンド不織布の厚さ方向が視野に入る倍率として画像を観察し、任意に選んだ、前記一方の表面（Ａ）が融着している部位について、面方向における同じ位置で前記他方の表面（Ｂ）が融着していれば、その箇所が融着部であると判断する。 In the present invention, whether or not a portion of the spunbond nonwoven fabric is a fused portion, that is, the fibers constituting the one surface (A) and the fibers constituting the other surface (B) To determine whether or not it is a fused portion, the cross section of the spunbond nonwoven fabric is observed with a scanning electron microscope at a magnification that allows the thickness direction of the spunbond nonwoven fabric to enter the field of view. If the other surface (B) is fused at the same position in the plane direction for the selected portion where the one surface (A) is fused, the location is determined to be the fused portion. do.
　融着部においては、前記一方の表面（Ａ）を構成する繊維と、前記他方の表面（Ｂ）を構成する繊維とが融着している箇所であるため、その周囲は繊維密度が高くなりやすい。このため、相対的に低密度である非融着部に吸収された水分は、相対的に高密度である融着部周辺へ毛管力差により導水することができ、面方向への水の移動が出来るようになる。 In the fused portion, since the fibers forming the one surface (A) and the fibers forming the other surface (B) are fused, the fiber density is high around the fused portion. Cheap. Therefore, the water absorbed in the relatively low-density non-fused portion can be guided to the periphery of the relatively high-density fused portion by the capillary force difference, and the water moves in the plane direction. will be able to
　さらに、融着部を特定の形態および特定の配列とすることにより、融着部を利用した面方向への水の移動をより顕著なものとし、特に優れた速乾性を発現できることを見出した。すなわち、融着部の形態および配列の制御により、ある融着部周辺に導水された水分をその他の融着部へも移動出来るようにすることで、吸水部で水が滞留することなく不織布面内に拡散するため、単純な厚み方向の水の移動のみよりも効率的にドライ性を発現しやすくし、優れた速乾性とすることができるのである。 In addition, it was found that by making the fused parts into a specific form and arrangement, the movement of water in the surface direction using the fused parts can be made more remarkable, and particularly excellent quick-drying can be achieved. That is, by controlling the form and arrangement of the fused portions, the water introduced to the periphery of a certain fused portion can also be transferred to other fused portions. Since it diffuses inside, the dryness can be expressed more efficiently than the simple movement of water in the thickness direction, and excellent quick-drying can be achieved.
　本発明のスパンボンド不織布では、前記非融着部の最小内接円の直径が、１．０ｍｍ以下であり、かつ、前記非融着部の最大内接円の直径が、２．０ｍｍ以上である。 In the spunbond nonwoven fabric of the present invention, the diameter of the minimum inscribed circle of the non-fused portion is 1.0 mm or less, and the diameter of the maximum inscribed circle of the non-fused portion is 2.0 mm or more. be.
　ここでいう前記非融着部に描ける最小内接円および最大内接円とは、以下のようにして求めるものである。 The minimum inscribed circle and the maximum inscribed circle that can be drawn in the non-fused portion mentioned here are obtained as follows.
　図１－１～図１－３に例示されるように、スパンボンド不織布１の表面をその上方から観察した際に、マイクロスコープで融着部１１に囲まれた非融着部が観察できる１０ｍｍ×１０ｍｍ以上の大きさの視野を撮影する。続いて、撮影した画像を用い、画像解析ソフトウェア（三谷商事（株）製「ＷｉｎＲＯＯＦ２０１５」）を用いて、非融着部１２上に配置できる最小内接円１３および最大内接円１４の直径を測定する。これを任意に抽出した同じ表面を構成する２０箇所について測定し、単純な数平均を求め、単位をｍｍとして、小数点第２位を四捨五入した値が本発明でいうその表面の最小内接円の直径および最大内接円の直径とする。 As illustrated in FIGS. 1-1 to 1-3, when the surface of the spunbond nonwoven fabric 1 is observed from above, the non-fused portion surrounded by the fused portion 11 can be observed with a microscope at a depth of 10 mm. A field of view with a size of ×10 mm or more is photographed. Subsequently, using the photographed image, the diameters of the minimum inscribed circle 13 and the maximum inscribed circle 14 that can be placed on the non-fused portion 12 were determined using image analysis software ("WinROOF2015" manufactured by Mitani Shoji Co., Ltd.). Measure. This is measured at 20 points arbitrarily extracted and constituting the same surface, a simple number average is obtained, the unit is mm, and the value rounded to the second decimal place is the minimum inscribed circle of the surface referred to in the present invention. Let it be the diameter and the diameter of the largest inscribed circle.
　前記最小内接円の直径は、値が小さいほど融着部同士が近接していることを示している。本発明のスパンボンド不織布では前記非融着部の最小内接円の直径が１．０ｍｍを超えると、融着部付近に導水された水分がその隣の融着部付近に移動し難くなり、効率的な面内拡散が期待できない。本発明のスパンボンド不織布では前記最小内接円の直径は０．８ｍｍ以下が好ましい範囲として挙げられる。一方、前記最小内接円の直径は０．２ｍｍ以上とすることが好ましい。前記最小内接円の直径下限を上記好ましい範囲とすれば、融着部同士が過剰に近接するのを防ぎ、融着点間を水分が通り抜けやすい。 The smaller the diameter of the minimum inscribed circle, the closer the fused parts are to each other. In the spunbonded nonwoven fabric of the present invention, when the diameter of the minimum inscribed circle of the non-fused portion exceeds 1.0 mm, the water introduced to the vicinity of the fused portion becomes difficult to move to the vicinity of the adjacent fused portion. Efficient in-plane diffusion cannot be expected. In the spunbond nonwoven fabric of the present invention, the diameter of the minimum inscribed circle is preferably 0.8 mm or less. On the other hand, it is preferable that the minimum inscribed circle has a diameter of 0.2 mm or more. If the lower limit of the diameter of the minimum inscribed circle is within the above preferable range, the fused portions are prevented from coming too close to each other, and moisture can easily pass between the fused points.
　また、前記最大内接円の直径は、値が大きいほど、融着している箇所から十分離れた箇所に低密度の部分を形成しやすいことを示している。本発明のスパンボンド不織布では前記非融着部の最大内接円の直径２．０ｍｍに満たないと、繊維密度の粗密が明瞭化せず、融着部へ導水され難くなるとともに、高い吸水速度が期待できない。前記最大内接円の直径は３．０ｍｍ以上が好ましい。一方、前記最大内接円の直径は１０．０ｍｍ以下とすることが好ましい。前記最大内接円の直径上限を上記好ましい範囲とすれば、融着部同士が過剰に離れるのを防ぎ、水分が残存し難くなる。 In addition, the larger the diameter of the maximum inscribed circle, the easier it is to form a low-density portion at a location sufficiently distant from the fused location. In the spunbonded nonwoven fabric of the present invention, if the diameter of the maximum inscribed circle of the non-fused portion is less than 2.0 mm, the coarseness and fineness of the fiber density will not be clarified, water will be difficult to be conveyed to the fused portion, and the water absorption rate will be high. cannot be expected. The diameter of the maximum inscribed circle is preferably 3.0 mm or more. On the other hand, the diameter of the maximum inscribed circle is preferably 10.0 mm or less. If the upper limit of the diameter of the maximum inscribed circle is set within the above preferable range, the fused portions are prevented from being excessively separated from each other, making it difficult for moisture to remain.
　また、本発明のスパンボンド不織布では、前記融着部が列状に連なって配置されている。 In addition, in the spunbond nonwoven fabric of the present invention, the fused portions are arranged in rows.
　本発明でいう、「列状に連なって配置される」とは、以下に示す様態であることを意味する。 "Arranged in a row" as used in the present invention means the mode shown below.
　図２に例示されるように、スパンボンド不織布２の表面をその上方から観察した際に、マイクロスコープで融着部２１が１０個以上観察できる１０ｍｍ×１０ｍｍ以上の大きさの視野を撮影する。続いて、撮影した画像を用い、画像解析ソフトウェア（アメリカ国立衛生研究所「ＩｍａｇｅＪ」）を用いて、画像の二値化処理を行い、画像内に観察できるすべての融着部について、それぞれ幾何学的な重心を求める。融着部２１の重心と最も重心間距離が近い融着部を融着部２２と定める。続いて、融着部２１を除き、融着部２２と最も重心間距離が近い融着部を融着部２３と定める。続いて、融着部２１および融着部２２を除き、融着部２３と最も重心間距離が近い融着部を融着部２４と定める。ここで、前記工程で定めた各融着部２１～２４それぞれの重心点をＭ２１～Ｍ２４とし、Ｍ２１とＭ２２を結んだ直線Ｌ１２、Ｍ２２とＭ２３を結んだ直線Ｌ２３、Ｍ２３とＭ２４を結んだ直線Ｌ３４を引く。Ｌ１２と、Ｌ２３およびＬ３４とが織りなす鋭角側の角度をそれぞれ計測し、θ１、θ２とする。このとき、θ１およびθ２がそれぞれ３０°以下であるとき、本発明でいう列状に連なって配置される状態である。 As illustrated in FIG. 2, when the surface of the spunbond nonwoven fabric 2 is observed from above, a field of view of 10 mm×10 mm or more in which 10 or more fused parts 21 can be observed is photographed with a microscope. Subsequently, using the captured image, image analysis software (National Institutes of Health "ImageJ") was used to perform image binarization, and geometric center of gravity. A fused portion having a center-of-gravity distance closest to the center of gravity of the fused portion 21 is defined as a fused portion 22 . Next, excluding the fused portion 21, the fused portion having the closest center-of-gravity distance to the fused portion 22 is defined as the fused portion 23. FIG. Next, excluding the fused portion 21 and the fused portion 22, the fused portion having the closest center-of-gravity distance to the fused portion 23 is defined as the fused portion 24. FIG. Here, the center of gravity of each of the fused portions 21 to 24 determined in the above steps is M21 to M24, a straight line L12 connecting M21 and M22, a straight line L23 connecting M22 and M23, and a straight line connecting M23 and M24. Pull L34. The acute angles formed by L12 and L23 and L34 are measured and defined as θ1 and θ2. At this time, when each of θ1 and θ2 is 30° or less, it is in a state of being arranged in a row as defined in the present invention.
　本発明のスパンボンド不織布では、融着部をこのように列状に連なって配置しない場合には、近接した融着部が直線的に配置されていることとはならず、融着部間での水の移動効率の向上は期待できず、水の面内拡散を促進することができない。 In the spunbonded nonwoven fabric of the present invention, when the fused portions are not arranged in a row like this, the adjacent fused portions are not arranged linearly, and the gap between the fused portions is not linear. However, the improvement of the water transfer efficiency cannot be expected, and the in-plane diffusion of water cannot be promoted.
　さらに、本発明のスパンボンド不織布では、融着部が間欠的に配置されることが好ましい。 Furthermore, in the spunbond nonwoven fabric of the present invention, it is preferable that the fused portions are intermittently arranged.
　本発明でいう、「融着部が間欠的に配置される」とは以下のような様態であることを意味する。 In the present invention, "the fused portions are arranged intermittently" means the following aspects.
　まず、スパンボンド不織布２の表面をその上方から観察した際に、マイクロスコープで融着部２１が１０個以上観察できる１０ｍｍ×１０ｍｍ以上の大きさの視野を撮影する。続いて、撮影した画像を用いて、前述の方法と同様にして、Ｍ２１～Ｍ２５を定める。ここで、Ｍ２１とＭ２２の距離（Ｄ１２）および、Ｍ２２とＭ２３の距離（Ｄ２３）および、Ｍ２３とＭ２４の距離（Ｄ３４）および、Ｍ２４とＭ２５の距離（Ｄ４５）を、単位をｍｍとして計測し、小数点第２位を四捨五入する。そして、以下の式（１）～（３）をともに満たすときが、本発明でいう融着部が間欠的に配置される状態である
　０．８×Ｄ１２≦　Ｄ２３　≦１．２×Ｄ１２　・・・式（１）
　０．８×Ｄ１２≦　Ｄ３４　≦１．２×Ｄ１２　・・・式（２）
　０．８×Ｄ１２≦　Ｄ４５　≦１．２×Ｄ１２　・・・式（３）。 First, when the surface of the spunbond nonwoven fabric 2 is observed from above, a field of view of 10 mm×10 mm or more in which 10 or more fused portions 21 can be observed is photographed with a microscope. Subsequently, using the photographed image, M21 to M25 are determined in the same manner as described above. Here, the distance between M21 and M22 (D12), the distance between M22 and M23 (D23), the distance between M23 and M24 (D34), and the distance between M24 and M25 (D45) are measured in units of mm, Round off to the second decimal place. When both of the following formulas (1) to (3) are satisfied, the fused portions are arranged intermittently as referred to in the present invention.・Formula (1)
0.8×D12≦D34≦1.2×D12 Expression (2)
0.8×D12≦D45≦1.2×D12 Expression (3).
　本発明のスパンボンド不織布では、このように融着部が間欠的に配置されることにより、融着部同士の水分移動が途切れることなく、より遠くまで水分を移動できるため、好ましい。 In the spunbond nonwoven fabric of the present invention, intermittently arranging the fused portions in this way is preferable because moisture can move farther without interruption of moisture transfer between the fused portions.
　また、本発明のスパンボンド不織布では、融着部の異形度が１．１以上である。 In addition, in the spunbonded nonwoven fabric of the present invention, the irregularity of the fused portion is 1.1 or more.
　前記融着部の異形度とは以下のようにして求めるものである。 The degree of irregularity of the fused portion is obtained as follows.
　まず、スパンボンド不織布の表面をその上方から観察した際に、マイクロスコープで融着部が３個以上観察できる倍率にて撮影する。続いて、撮影した画像を用い、画像解析ソフトウェア（前記「ＩｍａｇｅＪ」）を用いて、画像の二値化処理を行う。処理後の画像において、前記融着部に内接する最大内接円の直径および、前記融着部に外接する最小外接円の直径を、単位をｍｍとして計測し、最小外接円直径／最大内接円直径の値を算出する。これを任意に抽出した融着部２０か所について測定し、単純な数平均を求め、小数点第２位を四捨五入した値を本発明でいう、融着部の異形度とする。 First, when the surface of the spunbond nonwoven fabric is observed from above, it is photographed with a microscope at a magnification that allows three or more fused parts to be observed. Subsequently, using the captured image, the image is binarized using image analysis software (“ImageJ” described above). In the image after processing, the diameter of the maximum inscribed circle that inscribes the fused portion and the diameter of the minimum circumscribed circle that circumscribes the fused portion are measured in mm, and the minimum circumscribed circle diameter/maximum inscribed circle diameter is obtained. Calculate the circle diameter value. This is measured at 20 arbitrarily selected fused portions, a simple numerical average is calculated, and the value rounded to the second decimal place is defined as the irregularity of the fused portion referred to in the present invention.
　本発明のスパンボンド不織布は、融着部異形度が１．１に満たないと、融着部の輪郭が十分に長くならず、融着部周囲の高密度部領域が拡大しないため、水を引き込む能力を向上することができない。好ましくは１．５以上、さらに好ましくは１．７以上である。一方、融着部異形度を１０．０以下にすることが好ましい。融着部異形度上限を上記好ましい範囲とすれば、スパンボンド不織布の触感を良好に保つことができる。 In the spunbond nonwoven fabric of the present invention, if the irregularity of the fused portion is less than 1.1, the outline of the fused portion will not be sufficiently long, and the high-density region around the fused portion will not expand. You can't improve your ability to withdraw. It is preferably 1.5 or more, more preferably 1.7 or more. On the other hand, it is preferable to set the fused portion irregularity to 10.0 or less. By setting the upper limit of the irregularity of the fused portion within the above preferred range, the spunbond nonwoven fabric can maintain a good feel.
　本発明のスパンボンド不織布では、前記融着部におけるスパンボンド不織布の厚み（Ｔｍ）とスパンボンド不織布の厚み（Ｔ）との比（Ｔｍ／Ｔ）は、０．３０以下である。 In the spunbond nonwoven fabric of the present invention, the ratio (Tm/T) between the thickness (Tm) of the spunbond nonwoven fabric and the thickness (T) of the spunbond nonwoven fabric at the fused portion is 0.30 or less.
　本発明におけるスパンボンド不織布の厚みＴ（μｍ）は、形状測定機（例えば、（株）キーエンス製「ＶＲ３０００」）で測定した、無荷重での厚みを、任意の１０枚のサンプルについて、単位をμｍとして測定し、単純な数平均を求め、小数点第１位を四捨五入した値である。 The thickness T (μm) of the spunbond nonwoven fabric in the present invention is measured by a shape measuring machine (for example, “VR3000” manufactured by Keyence Corporation), and the thickness without load is measured for any 10 samples. It is a value obtained by measuring in μm, obtaining a simple number average, and rounding off to the first decimal place.
　また、融着部の厚みＴｍ（μｍ）は、以下のようにして求めるものである。 Also, the thickness Tm (μm) of the fused portion is obtained as follows.
　まず、スパンボンド不織布の機械方向と直行する断面を走査型電子顕微鏡（ＳＥＭ）でスパンボンド不織布の厚みが観察できる倍率として画像を撮影する。撮影された不織布断面画像を用いて、融着部の厚み（単位はμｍ）を測定する。これと同様の動作を異なる１０箇所について行った結果の単純な数平均を求め、小数点第１位を四捨五入した値が融着部の厚みＴｍ（μｍ）である。 First, an image of a cross section perpendicular to the machine direction of the spunbond nonwoven fabric is taken with a scanning electron microscope (SEM) at a magnification that allows observation of the thickness of the spunbond nonwoven fabric. Using the photographed nonwoven fabric cross-sectional image, the thickness (unit: μm) of the fused portion is measured. The thickness Tm (μm) of the fused portion is obtained by calculating a simple numerical average of the results obtained by performing the same operation at ten different locations and rounding off to the first decimal place.
　上記操作により計測したＴおよびＴｍを用いて、Ｔｍ／Ｔの値を計算し、小数点第３位を四捨五入した値を算出する。 　Using T and Tm measured by the above operation, calculate the value of Tm/T, and calculate the value rounded to the third decimal place.
　本発明のスパンボンド不織布では、スパンボンド不織布の厚みとスパンボンド不織布の厚みとの比（Ｔｍ／Ｔ）が０．３０を超えると、融着部周囲の繊維密度を十分に高くすることができなくなるため、水を引き込む能力を向上することができない。 In the spunbond nonwoven fabric of the present invention, when the ratio (Tm/T) of the thickness of the spunbond nonwoven fabric to the thickness of the spunbond nonwoven fabric exceeds 0.30, the fiber density around the fused portion can be sufficiently increased. It cannot improve its ability to draw water.
　融着部周囲をより高密度化し、非融着部からの導水効率を向上させる観点から、Ｔｍ／Ｔは０．２５以下とすることが好ましく、より好ましくは０．２０以下である。一方、Ｔｍ／Ｔは０．０１以上とすることが好ましい。Ｔｍ／Ｔの下限を上記好ましい範囲とすれば、融着部が過剰に薄くならず、スパンボンド不織布の強度低下を防止できる。 From the viewpoint of increasing the density around the fused portion and improving the water conduction efficiency from the non-fused portion, Tm/T is preferably 0.25 or less, more preferably 0.20 or less. On the other hand, Tm/T is preferably 0.01 or more. When the lower limit of Tm/T is set within the above preferred range, the fused portion does not become excessively thin, and the reduction in strength of the spunbond nonwoven fabric can be prevented.
　また、本発明のスパンボンド不織布では、融着部の面積比率が５％以上であることが好ましい。融着部の面積比率を係る範囲とすれば、融着部が十分に存在するため、非融着部に水分が残存しにくくなる。一方、前記面積比率は３０％以下とすることが好ましい。前記面積比率の上限を上記好ましい範囲とすれば、不織布の触感を損ねることがない。 In addition, in the spunbonded nonwoven fabric of the present invention, it is preferable that the area ratio of the fused portion is 5% or more. If the area ratio of the fused portion is set within the range, the fused portion is sufficiently present, and moisture is less likely to remain in the non-fused portion. On the other hand, the area ratio is preferably 30% or less. When the upper limit of the area ratio is set within the above preferred range, the feel of the nonwoven fabric is not impaired.
　さらに、本発明のスパンボンド不織布では、前記一方の表面（Ａ）において、融着部が前記他方の表面（Ｂ）に向かう凹部を形成している。前記一方の表面（Ａ）において、融着部が前記他方の表面（Ｂ）に向かう凹部を形成していないと、相対的に繊維径が太い繊維から構成される表面（Ａ）の繊維間空隙サイズを拡張できず、表裏の粗密差が拡大せず、ドライ性の向上が期待できない。 Furthermore, in the spunbonded nonwoven fabric of the present invention, the fused portion forms a concave portion facing the other surface (B) on the one surface (A). On the one surface (A), if the fused portion does not form a concave portion facing the other surface (B), the inter-fiber gaps on the surface (A) composed of fibers having a relatively large fiber diameter The size cannot be expanded, the density difference between the front and back surfaces cannot be increased, and the dryness cannot be improved.
　また、本発明のスパンボンド不織布は、スパンボンド不織布の前記一方の表面（Ａ）および前記他方の表面（Ｂ）の、水との接触角がともに３０°以下であることが好ましい。より好ましくは２０°以下、さらに好ましくは１０°以下である。前記水との接触角が上記好ましい範囲であると、スパンボンド不織布表面に接触した水が不織布に吸水されやすい。また、本発明における水との接触角の下限は０°であるが、水との接触角が０°とは、後述の測定方法においてすべての水が不織布に吸水された状態をいう。 In addition, in the spunbond nonwoven fabric of the present invention, it is preferable that both the one surface (A) and the other surface (B) of the spunbond nonwoven fabric have contact angles with water of 30° or less. It is more preferably 20° or less, still more preferably 10° or less. When the contact angle with water is within the above preferable range, the nonwoven fabric easily absorbs water that contacts the surface of the spunbond nonwoven fabric. The lower limit of the contact angle with water in the present invention is 0°, and the 0° contact angle with water means that all the water is absorbed by the nonwoven fabric in the measurement method described later.
　なお、スパンボンド不織布の表面の水との接触角は、スパンボンド不織布を構成する繊維に用いられる熱可塑性樹脂の親水性や後工程による親水性油剤付与によって制御することができる。例えば、上記熱可塑性樹脂の親水性が高いほど、また親水性油剤の付着量が多いほど、水との接触角は小さくなる傾向にある。 The contact angle with water on the surface of the spunbonded nonwoven fabric can be controlled by the hydrophilicity of the thermoplastic resin used for the fibers that make up the spunbonded nonwoven fabric or by applying a hydrophilic oil in a post-process. For example, the contact angle with water tends to decrease as the hydrophilicity of the thermoplastic resin increases and as the amount of hydrophilic oil applied increases.
　本発明におけるスパンボンド不織布の表面の水との接触角は、以下の方法で測定し、算出された値を指す。 The contact angle with water on the surface of the spunbond nonwoven fabric in the present invention refers to a value calculated by measuring by the following method.
　（１）スパンボンド不織布を、室温２０℃、相対湿度６５％の室内に２４時間以上放置する。 (1) Leave the spunbond nonwoven fabric in a room with a room temperature of 20°C and a relative humidity of 65% for 24 hours or more.
　（２）上記処理を施したスパンボンド不織布を、同室に設置した接触角計のステージ上に、前記一方の表面（Ａ）が測定面となるようにセットする。 (2) Set the spunbond nonwoven fabric that has undergone the above treatment on the stage of the contact angle meter installed in the same room so that the one surface (A) serves as the measurement surface.
　（３）イオン交換水からなる２μＬの液滴を針先に作製し、不織布に着液させる。 (3) A droplet of 2 μL made of ion-exchanged water is prepared on the tip of the needle and applied to the nonwoven fabric.
　（４）不織布に液滴が着液してから２秒後の画像より、液滴との接触角を求める。なお、２秒以内にすべての水が不織布に吸水された場合は、液滴の空気との界面が不織布層の表面と同一面に存在すると判断し、水との接触角を０°と定義する。 (4) Obtain the contact angle with the droplet from the image two seconds after the droplet has landed on the nonwoven fabric. If all the water is absorbed by the nonwoven fabric within 2 seconds, it is determined that the interface between the droplet and the air is on the same plane as the surface of the nonwoven fabric layer, and the contact angle with water is defined as 0°. .
　（５）１水準につき測定位置を変更して５回測定を行い、その算術平均値を前記一方の表面（Ａ）と水との接触角とする。 (5) Change the measurement position for each level and measure five times, and take the arithmetic average value as the contact angle between the one surface (A) and water.
　（６）（１）と同様の処理を施したスパンボンド不織布を、前記一方の表面（Ａ）が裏面となるようにセットし、上記（２）～（５）の操作を繰り返し行い、その算術平均値を前記他方の表面（Ｂ）と水との接触角とする。 (6) The spunbond nonwoven fabric treated in the same manner as in (1) is set so that the one surface (A) is the back surface, and the above operations (2) to (5) are repeated, and the arithmetic Let the average value be the contact angle between the other surface (B) and water.
　本発明のスパンボンド不織布は、前記一方の表面（Ａ）で測定された吸水速度が２０秒以下であることが好ましい。吸水速度を好ましくは２０秒以下、より好ましくは１５秒以下、さらに好ましくは１０秒以下とすることにより、表面に付着した水分を取り除く性能が良好である、すなわち吸水性に優れる不織布となる。 The spunbond nonwoven fabric of the present invention preferably has a water absorption rate of 20 seconds or less as measured on the one surface (A). By setting the water absorption rate to preferably 20 seconds or less, more preferably 15 seconds or less, and even more preferably 10 seconds or less, the nonwoven fabric has good performance in removing moisture adhering to the surface, that is, excellent water absorption.
　ここでいう吸水速度とは、ＪＩＳ　Ｌ　１９０７：２０１０「繊維製品の吸水性試験方法」の「７．１．１　滴下法」に基づき測定されるものである。スパンボンド不織布に水滴を１滴滴下し、吸収されて表面の鏡面反射が消失するまでの時間を測定し、これを異なる１０箇所で測定した値の単純平均を算出し、単位を秒として、小数点第１位を四捨五入した値を、本発明で言う吸水速度とする。 The water absorption rate referred to here is measured based on "7.1.1 Dropping method" of JIS L 1907:2010 "Water absorption test method for textile products". Drop one drop of water onto the spunbond nonwoven fabric, measure the time it takes for the specular reflection on the surface to disappear after being absorbed, and calculate the simple average of the values measured at 10 different points. The value obtained by rounding off the first place is defined as the water absorption speed referred to in the present invention.
　また、本発明のスパンボンド不織布の目付は、１０～１００ｇ／ｍ２とすることが好ましい。 The spunbond nonwoven fabric of the present invention preferably has a basis weight of 10 to 100 g/m 2 .
　目付を好ましくは１０ｇ／ｍ２以上、より好ましくは１３ｇ／ｍ２以上、さらに好ましくは１５ｇ／ｍ２以上とすることにより、実用に供し得る機械的強度のスパンボンド不織布を得ることができる。一方、目付を好ましくは１００ｇ／ｍ２以下、より好ましくは５０ｇ／ｍ２以下とすることにより、衛生材料用の不織布としての使用に適した適度な柔軟性を有するスパンボンド不織布とすることができる。 By setting the basis weight to preferably 10 g/m 2 or more, more preferably 13 g/m 2 or more, and even more preferably 15 g/m 2 or more, it is possible to obtain a spunbond nonwoven fabric with mechanical strength suitable for practical use. On the other hand, by setting the basis weight to preferably 100 g/m 2 or less, more preferably 50 g/m 2 or less, a spunbonded nonwoven fabric having moderate flexibility suitable for use as a nonwoven fabric for sanitary materials can be obtained. .
　なお、本発明におけるスパンボンド不織布の目付（ｇ／ｍ２）とは、ＪＩＳ　Ｌ　１９１３：２０１０「一般不織布試験方法」の「６．２　単位面積当たりの質量」に基づき、２０ｃｍ×２５ｃｍの試験片を、試料の幅１ｍ当たり３枚採取し、標準状態におけるそれぞれの質量（ｇ）を量り、その平均値から算出する１ｍ２当たりの質量を指すこととする。 The basis weight (g/m 2 ) of the spunbond nonwoven fabric in the present invention is a 20 cm × 25 cm test piece based on "6.2 Mass per unit area" of JIS L 1913:2010 "General nonwoven fabric test method". 3 samples are sampled per 1 m width of the sample, the mass (g) of each sample is weighed under standard conditions, and the mass per 1 m 2 is calculated from the average value.
　本発明のスパンボンド不織布は、本発明の効果を損なわない範囲で、目的に応じてスパンボンド不織布の層（Ｓ）とメルトブロー不織布の層（Ｍ）とを積層して配置することができる。これらの積層配置の例としては、ＳＭＳ、ＳＭＭＳ、ＳＳＭＭＳ、およびＳＭＳＭＳなどのような態様が挙げられる。これらの場合は、積層した不織布の一方の表面をスパンボンド不織布の表面（Ａ）、もう一方の表面を、表面（Ｂ）とみなす。 In the spunbonded nonwoven fabric of the present invention, the layer (S) of the spunbonded nonwoven fabric and the layer (M) of the meltblown nonwoven fabric can be laminated according to the purpose, as long as the effects of the present invention are not impaired. Examples of these stacking arrangements include aspects such as SMS, SMMS, SSMMS, and SMSMS. In these cases, one surface of the laminated nonwoven fabric is regarded as the surface (A) of the spunbond nonwoven fabric, and the other surface is regarded as the surface (B).
　なお、本発明のスパンボンド不織布は、吸水性をより高くすることを目的として、親水化剤を付与しても良い。親水化剤の種類としては、界面活性剤などが挙げられるが、中でも非イオン性界面活性剤が好ましい。 The spunbonded nonwoven fabric of the present invention may be provided with a hydrophilizing agent for the purpose of increasing the water absorption. Types of hydrophilizing agents include surfactants, among which nonionic surfactants are preferred.
　［スパンボンド不織布の製造方法］
　次に、本発明のスパンボンド不織布を製造する好ましい態様を、具体的に説明する。 [Method for producing spunbond nonwoven fabric]
Next, preferred embodiments for producing the spunbond nonwoven fabric of the present invention will be specifically described.
　本発明のスパンボンド不織布は、原料である熱可塑性樹脂を溶融し、紡糸口金から紡糸した後、冷却固化して得られた糸条に対し、エジェクターで牽引し延伸して、移動するネット上に捕集して不織繊維ウェブ化した後、熱融着する工程を要する、スパンボンド法によって製造される。 The spunbond nonwoven fabric of the present invention is produced by melting a thermoplastic resin as a raw material, spinning it from a spinneret, and then cooling and solidifying the yarn obtained by cooling and solidifying it. It is produced by a spunbond process, which requires a step of heat-sealing after collection to form a nonwoven fibrous web.
　用いられる紡糸口金やエジェクターの形状としては、丸形や矩形等種々のものを採用することができる。中でも、圧縮エアの使用量が比較的少なく、糸条同士の融着や擦過が起こりにくいという観点から、矩形口金と矩形エジェクターの組み合わせを用いることが好ましい態様である。 Various shapes such as round and rectangular can be adopted as the shape of the spinneret and ejector to be used. Among them, it is preferable to use a combination of a rectangular mouthpiece and a rectangular ejector from the viewpoint that the amount of compressed air used is relatively small and the threads are less likely to fuse or rub against each other.
　本発明における、紡糸温度は、（原料である熱可塑性樹脂の融解温度＋１０℃）以上（原料である熱可塑性樹脂の融解温度＋１００℃）以下とすることが好ましい。紡糸温度を上記範囲内とすることにより、安定した溶融状態とし、優れた紡糸安定性を得ることができる。 In the present invention, the spinning temperature is preferably (the melting temperature of the raw material thermoplastic resin + 10°C) or more and (the melting temperature of the raw material thermoplastic resin + 100°C) or less. By setting the spinning temperature within the above range, a stable molten state can be obtained and excellent spinning stability can be obtained.
　紡出された糸条は、次に冷却されるが、紡出された糸条を冷却する方法としては、例えば、冷風を強制的に糸条に吹き付ける方法、糸条周りの雰囲気温度で自然冷却する方法、および紡糸口金とエジェクター間の距離を調整する方法等が挙げられ、またはこれらの方法を組み合わせる方法を採用することができる。また、冷却条件は、紡糸口金の単孔あたりの吐出量、紡糸する温度および雰囲気温度等を考慮して適宜調整して採用することができる。 The spun yarn is then cooled. Methods for cooling the spun yarn include, for example, a method of forcibly blowing cold air onto the yarn, and natural cooling at the ambient temperature around the yarn. and a method of adjusting the distance between the spinneret and the ejector, or a method of combining these methods. Also, the cooling conditions can be appropriately adjusted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the ambient temperature, and the like.
　次に、冷却固化された糸条は、エジェクターから噴射される圧縮エアによって牽引され、延伸される。 Next, the cooled and solidified yarn is pulled and stretched by compressed air jetted from the ejector.
　本発明のスパンボンド不織布では、前記一方の表面（Ａ）および前記他方の表面（Ｂ）を構成する繊維の平均単繊維直径の制御が重要となる。 In the spunbond nonwoven fabric of the present invention, it is important to control the average single fiber diameter of the fibers constituting the one surface (A) and the other surface (B).
　繊維の平均単繊維直径は、紡糸口金の吐出孔当たりの吐出量と牽引速度、すなわち紡糸速度によって決定される。このため、所望の平均単繊維直径に応じて、吐出量と紡糸速度を決定することが好ましい。 The average single fiber diameter of the fiber is determined by the discharge amount per discharge hole of the spinneret and the drawing speed, that is, the spinning speed. Therefore, it is preferable to determine the discharge rate and the spinning speed according to the desired average single fiber diameter.
　紡糸速度においては、２，０００ｍ／分以上であることが好ましく、より好ましくは３，０００ｍ／分以上である。紡糸速度を２，０００ｍ／分以上とすることにより、高い生産性を有することになり、また繊維の配向結晶化が進み高い強度の長繊維を得ることができる。 The spinning speed is preferably 2,000 m/min or more, more preferably 3,000 m/min or more. By setting the spinning speed to 2,000 m/min or more, high productivity can be obtained, and the orientation and crystallization of the fibers can be advanced to obtain long fibers with high strength.
　このように牽引により延伸された長繊維糸条は、移動するネットに捕集されることでシート化された後に、熱融着する工程に供される。 The long fiber yarn drawn by pulling in this way is collected by a moving net to be formed into a sheet, and then subjected to a heat-sealing process.
　本発明のスパンボンド不織布は、構成繊維の繊維径の異なる前記一方の表面（Ａ）と前記他方の表面（Ｂ）を有する。このようなスパンボンド不織布を得る方法としては、例えば、前記一方の表面（Ａ）用の紡糸口金から、前記のとおり捕集ネット上に捕集して得た繊維ウェブの上に、捕集ネットの下流側に配された、前記他方の表面（Ｂ）用の紡糸口金から、繊維ウェブを堆積させ、これらを一気に熱融着させて、固定する方法などを採用することができる。２つの不織布層を積層する方法としては、例えば、上記のとおり捕集ネット上にスパンボンド法により第１の熱可塑性樹脂繊維を捕集して得た不織布層の上に、スパンボンド法により第２の熱可塑性樹脂繊維を捕集して得た不織布層をインラインで連続的に捕集し、積層一体化する方法、別々に得た前記一方の表面（Ａ）および前記他方の表面（Ｂ）を構成する不織ウェブをオフラインで重ね合わせ、熱圧着などにより積層一体化する方法などを採用することができる。中でも生産性に優れているということから、捕集ネット上にスパンボンド法により前記一方の表面（Ａ）を構成する熱可塑性樹脂繊維を捕集して得た不織ウェブの上に、スパンボンド法により前記他方の表面（Ｂ）を構成する熱可塑性樹脂繊維を捕集して得た不織ウェブをインラインで連続的に捕集、熱接着により積層一体化する方法が好ましい様態である。 The spunbond nonwoven fabric of the present invention has the one surface (A) and the other surface (B) having different fiber diameters of constituent fibers. As a method for obtaining such a spunbond nonwoven fabric, for example, a collection net is placed on the fiber web obtained by collection on the collection net as described above from the spinneret for the one surface (A). A method of depositing a fibrous web from the spinneret for the other surface (B) arranged downstream of the above, heat-sealing them all at once, and fixing them can be adopted. As a method for laminating two nonwoven fabric layers, for example, on the nonwoven fabric layer obtained by collecting the first thermoplastic resin fibers on the collection net by the spunbond method as described above, the second nonwoven fabric layer is formed by the spunbond method. 2. A method of continuously collecting nonwoven fabric layers obtained by collecting thermoplastic resin fibers in line and laminating and integrating them, and separately obtaining the one surface (A) and the other surface (B). The nonwoven webs constituting the are superimposed offline, and a method of laminating and integrating by thermocompression bonding or the like can be adopted. Above all, it is said that the productivity is excellent, so that a spunbonded A preferred embodiment is a method in which the nonwoven web obtained by collecting the thermoplastic resin fibers constituting the other surface (B) by the method is continuously collected in-line and laminated and integrated by heat bonding.
　本発明のスパンボンド不織布を熱接着により積層一体化する方法としては、上下一対のロール表面にそれぞれ彫刻（凹凸部）が施された熱エンボスロール、片方のロール表面がフラット（平滑）なロールと他方のロール表面に彫刻（凹凸部）が施されたロールとの組み合わせからなる熱エンボスロール、および上下一対のフラット（平滑）ロールの組み合わせからなる熱カレンダーロールなど、各種ロールにより熱接着する方法や、ホーンの超音波振動により熱溶着させる超音波接着などの熱圧着による方法を採用することができる。 As a method for laminating and integrating the spunbond nonwoven fabric of the present invention by thermal bonding, a thermal embossing roll having a pair of upper and lower rolls each having an engraving (concavo-convex portion) on its surface, and a roll having a flat (smooth) surface on one roll. A method of heat bonding using various rolls, such as a heat embossing roll that is combined with a roll with engraving (unevenness) on the surface of the other roll, and a heat calender roll that is a combination of a pair of upper and lower flat (smooth) rolls. Alternatively, a method using thermocompression bonding such as ultrasonic bonding in which thermal bonding is performed by ultrasonic vibration of a horn can be adopted.
　中でも、エンボスロールで熱融着することにより本発明のスパンボンド不織布を製造した場合には、エンボスロールの凸部に対応する位置で、前記一方の表面（Ａ）と前記他方の表面（Ｂ）を構成する繊維を、ともに融着させやすいため好ましい。また、エンボスロールの凸部の位置や形状を設計することによって、融着部の配置、形状を容易に制御できる点でも、好ましい態様である。 Above all, when the spunbond nonwoven fabric of the present invention is produced by heat-sealing with an embossing roll, the one surface (A) and the other surface (B) are bonded at positions corresponding to the convex portions of the embossing roll. It is preferable because the fibers constituting the are easily fused together. In addition, this is also a preferred embodiment in that the arrangement and shape of the fused portion can be easily controlled by designing the position and shape of the projections of the embossing roll.
　本発明のスパンボンド不織布を、エンボスロールによる熱圧着にて製造する場合には、ロール間でスパンボンドが受ける線圧を５０Ｎ／ｃｍ以上とすることで、融着部の周囲を十分に緻密化できるため、好ましい。より好ましくは、１００Ｎ／ｃｍである。 When the spunbonded nonwoven fabric of the present invention is produced by thermocompression bonding using embossing rolls, the line pressure applied to the spunbond between the rolls is set to 50 N/cm or more to sufficiently densify the periphery of the fused portion. preferred because it can be done. More preferably, it is 100 N/cm.
　また、融着部を十分に接着させ、緻密化できる観点から、エンボスロールの表面温度は、（原料である熱可塑性樹脂の融解温度－８０℃）以上（原料である熱可塑性樹脂の融解温度－１０℃）以下とすることが好ましい。 In addition, from the viewpoint that the fused portion can be sufficiently bonded and densified, the surface temperature of the embossing roll should be (the melting temperature of the raw material thermoplastic resin -80 ° C.) or higher (the melting temperature of the raw material thermoplastic resin - 10° C.) or less.
　さらに、本発明のスパンボンド不織布においては、前記一方の表面（Ａ）側を彫刻が施された熱エンボスロール、前記他方の表面（Ｂ）側をフラットロールとして加工することが好ましい。 Furthermore, in the spunbond nonwoven fabric of the present invention, it is preferable to process the one surface (A) side as a heat embossed roll with engraving and the other surface (B) side as a flat roll.
　このようにして得られたスパンボンド不織布に対し、巻取り前に親水化剤を付与しても良い。スパンボンド不織布への親水化剤の付与方法としては、キスロールやスプレーによる塗布やディップコーティングなどが挙げられるが、均一性や付着量制御の容易さからキスロールによる塗布が好ましい。 A hydrophilizing agent may be added to the spunbonded nonwoven fabric thus obtained before winding. Examples of the method for applying the hydrophilizing agent to the spunbond nonwoven fabric include application by a kiss roll, spray, and dip coating, but application by a kiss roll is preferable from the viewpoint of uniformity and ease of control of the amount of adhesion.
　次に、実施例に基づき本発明を詳細に説明する。ただし、本発明はこれらの実施例のみに限定されるものではない。なお、各物性の測定において、特段の記載がないものは、前述の方法に基づいて測定を行ったものである。 Next, the present invention will be described in detail based on examples. However, the present invention is not limited only to these examples. In the measurement of each physical property, unless otherwise specified, the measurement was performed according to the method described above.
　（１）目付
　目付は、ＪＩＳ　Ｌ　１９１３：２０１０「一般不織布試験方法」の「６．２　単位面積当たりの質量」に基づき測定した。 (1) Fabric weight The fabric weight was measured based on "6.2 Mass per unit area" of JIS L 1913:2010 "General nonwoven fabric test methods".
　（２）前記一方の表面（Ａ）の平均単繊維直径（Ｄａ）に対する前記他方の表面（Ｂ）の平均単繊維直径（Ｄｂ）の比（Ｄａ／Ｄｂ）
　それぞれの繊維について、ネット上に捕集した不織繊維ウェブからランダムに繊維サンプル採取し、繊維の横断面を（株）日立ハイテクノロジーズ製の走査型電子顕微鏡「Ｓ－５５００」で１本の繊維が観察できる倍率として画像を撮影した。その後、画像解析ソフトウェアとして、前記「ＷｉｎＲＯＯＦ２０１５」を用い、前述のとおり測定を行った。 (2) Ratio (Da/Db) of the average single fiber diameter (Db) of the other surface (B) to the average single fiber diameter (Da) of the one surface (A)
For each fiber, a fiber sample was randomly collected from the nonwoven fiber web collected on the net, and the cross section of the fiber was examined with a scanning electron microscope "S-5500" manufactured by Hitachi High Technologies Co., Ltd. One fiber The image was taken at a magnification that allows observation of . After that, using the "WinROOF2015" as the image analysis software, the measurement was performed as described above.
　（３）融着部の有無
　作製したスパンボンド不織布の表面（Ａ）側を、（株）キーエンス製のデジタルマイクロスコープ「ＶＨＸ－６０００」で１５ｍｍ×１５ｍｍの視野範囲について画像を撮影し、前述の通り測定を行った。 (3) Presence or absence of fused portion The surface (A) side of the spunbond nonwoven fabric prepared was photographed with a digital microscope "VHX-6000" manufactured by KEYENCE CORPORATION in a field of view of 15 mm × 15 mm. I took measurements along the way.
　（４）非融着部の最大内接円の直径および最大内接円の直径
　作製したスパンボンド不織布の表面（Ａ）側を、前記デジタルマイクロスコープ「ＶＨＸ－６０００」で１５ｍｍ×１５ｍｍの視野範囲について画像を撮影した。その後、画像解析ソフトウェアとして、前記「ＷｉｎＲＯＯＦ２０１５」を用い、前述のとおり測定を行った。 (4) Diameter of the maximum inscribed circle and diameter of the maximum inscribed circle of the non-fused portion The surface (A) side of the spunbonded nonwoven fabric was observed with a field of view of 15 mm × 15 mm with the digital microscope "VHX-6000". I took a picture of. After that, using the "WinROOF2015" as the image analysis software, the measurement was performed as described above.
　（５）融着部の異形度
　作製したスパンボンド不織布の前記一方の表面（Ａ）側を、前記デジタルマイクロスコープ「ＶＨＸ－６０００」で融着部が４箇所観察できる倍率として画像を撮影した。その後、画像解析ソフトウェアとして、前記「ＷｉｎＲＯＯＦ２０１５」を用い、前述のとおり測定を行った。 (5) Irregularity of Fused Portion An image of the one surface (A) side of the spunbonded nonwoven fabric was photographed with the digital microscope “VHX-6000” at a magnification such that four fused portions can be observed. After that, using the "WinROOF2015" as the image analysis software, the measurement was performed as described above.
　（６）スパンボンド不織布の厚みに対する融着部の厚み比率（Ｔｍ／Ｔ）
　スパンボンド不織布の厚みについては、（株）キーエンス製の３Ｄ形状測定機「ＶＲ－３０５０」を用い、前述の通り測定を行った。 (6) Ratio of thickness of fused portion to thickness of spunbond nonwoven fabric (Tm/T)
The thickness of the spunbond nonwoven fabric was measured as described above using a 3D shape measuring machine "VR-3050" manufactured by Keyence Corporation.
　作製したスパンボンド不織布の横断面を、繊維の横断面を（株）日立ハイテクノロジーズ製の走査型電子顕微鏡「Ｓ－５５００」で１本の繊維が観察できる倍率として画像を撮影した。その後、画像解析ソフトウェアとして、前記「ＷｉｎＲＯＯＦ２０１５」を用い、前述のとおり融着部の厚み測定を行った。 An image of the cross section of the spunbonded nonwoven fabric was taken with a scanning electron microscope "S-5500" manufactured by Hitachi High-Technologies Co., Ltd. at a magnification that allows observation of one fiber. Thereafter, the thickness of the fused portion was measured as described above using the "WinROOF2015" as image analysis software.
　（７）スパンボンド不織布の水との接触角
　協和界面科学（株）製の接触角計「ＤＭｏ－５０１」を用い、前述のとおり測定を行った。　 (7) Contact angle of spunbond nonwoven fabric with water Measurement was performed as described above using a contact angle meter "DMo-501" manufactured by Kyowa Interface Science Co., Ltd.
　（８）ドライ性
　作製したスパンボンド不織布について、以下の測定を行った。
手順１：スパンボンド不織布から、５ｃｍ×５ｃｍのサンプルを切り出す。
手順２：ＪＩＳ　Ｐ　３８０１の２種に準拠したろ紙を５ｃｍ×５ｃｍに切り出したものを１回の測定につき２枚用意し、それぞれ質量を測定する。
手順３：ポリプロピレン製のフィルムの上に、生理食塩水０．２５０±０．００５ｍＬを滴下する。この際、滴下する生理食塩水の質量を測定しておく。
手順４：滴下した生理食塩水の上から、前記一方の表面（Ａ）を下向きにしてスパンボンド不織布を乗せ、１分間保持する。
手順５：前記手順４の保持後にスパンボンド不織布を前記ポリプロピレン製のフィルムから外し、前記ろ紙の１枚目の上に前記一方の表面（Ａ）を上向きにして乗せ、さらにその上から前記ろ紙の２枚目を速やかに乗せる。
手順６：前記２枚目のろ紙の上から圧力が５ｇ／ｃｍ２となるように１２５ｇの重りをのせ、１分間保持する。
手順７：前記手順６の保持後に重りを外し、各ろ紙の質量を測定し、それぞれのろ紙の質量増加分を算出する。
手順８：下記式から、前記スパンボンド不織布におけるそれぞれの表面の配水比率を算出する。
配水比率（％）＝１００×Ｗ１／Ｗ０
　ここに、
Ｗ０：上記手順３において滴下した生理食塩水の質量（ｇ）
Ｗ１：上記手順７において表面（Ａ）に当てたろ紙の質量増加分（ｇ）。
以上の動作を異なる１０サンプルについて実施し、単純な数平均を算出し、小数点第１位で四捨五入した値を、配水比率とした。
得られた配水比率をもとに、次の４段階で評価した。 (8) Dryness The following measurements were performed on the produced spunbonded nonwoven fabric.
Procedure 1: Cut out a 5 cm x 5 cm sample from the spunbond nonwoven fabric.
Procedure 2: Two sheets of 5 cm x 5 cm cut out from JIS P 3801 type 2 filter paper are prepared for each measurement, and the mass of each sheet is measured.
Procedure 3: Drop 0.250±0.005 mL of physiological saline onto a polypropylene film. At this time, the mass of the physiological saline to be dripped is measured.
Procedure 4: A spunbonded nonwoven fabric is placed on top of the dropped physiological saline with the one surface (A) facing downward, and held for 1 minute.
Step 5: After holding the step 4, remove the spunbond nonwoven fabric from the polypropylene film, place it on the first filter paper with the one surface (A) facing up, and then place the filter paper on top of it. Put the second one on quickly.
Step 6: Place a weight of 125 g on the second filter paper so that the pressure is 5 g/cm 2 and hold for 1 minute.
Step 7: After holding in step 6 above, the weight is removed, the mass of each filter paper is measured, and the increase in mass of each filter paper is calculated.
Step 8: Calculate the water distribution ratio of each surface of the spunbond nonwoven fabric from the following formula.
Water distribution ratio (%) = 100 x W1/W0
Here,
W0: Mass (g) of physiological saline dripped in the above procedure 3
W1: Mass increase (g) of the filter paper applied to the surface (A) in the procedure 7 above.
The above operation was performed for 10 different samples, a simple number average was calculated, and the value rounded to the first decimal place was used as the water distribution ratio.
Based on the obtained water distribution ratio, evaluation was made in the following four stages.
　４：配水比率２０％未満
　３：配水比率２０％以上、３０％未満
　２：配水比率３０％以上、４０％未満
　１：配水比率４０％以上。 4: Water distribution ratio less than 20% 3: Water distribution ratio 20% or more and less than 30% 2: Water distribution ratio 30% or more and less than 40% 1: Water distribution ratio 40% or more.
　（９）速乾性
　作製したスパンボンド不織布を、前記一方の表面（Ａ）を上にしてポリプロピレン製のフィルムの上におき、その上から０．１ｃｃの水滴を１滴滴下し、３０秒間経過した後の表面の触感について健康な一般成人（男女１５名ずつ計３０名）が手で触り、次の３段階で評価した。各不織布について評価結果の平均点を算出し、そのスパンボンド不織布の肌触りとした。 (9) Quick-drying property The prepared spunbond nonwoven fabric was placed on a polypropylene film with the one surface (A) facing up, and one 0.1 cc water droplet was dropped from above, and 30 seconds passed. Healthy general adults (total of 30 persons, 15 males and 15 females) touched the tactile sensation of the surface afterward with their hands, and evaluated it according to the following three grades. The average score of the evaluation results was calculated for each nonwoven fabric, and the feel of the spunbond nonwoven fabric was obtained.
　５：表面がサラサラしており、水分を感じない
　３：表面に水分はないが、しっとりしている
　１：表面に水分があり、しっとりしている。 5: The surface is smooth and does not feel moisture. 3: The surface is moist although there is no moisture. 1: The surface is moist and moist.
　［実施例１］
　（一方の表面（Ａ）を形成する繊維ウェブ）
　ポリプロピレン（ＰＰ）を押出機で溶融し、孔径φが０．４ｍｍの丸孔を有した矩形口金から、単孔吐出量が０．８ｇ／分で紡出した。紡出した糸条を、冷却固化した後、矩形エジェクターにおいてエジェクターでの圧力を０．０８ＭＰａとした圧縮エアによって、牽引・延伸し、移動するネット上に捕集して不織繊維ウェブを得た。得られた一方の表面（Ａ）を構成する繊維の平均単繊維直径は２０．４μｍであった。 [Example 1]
(Fibrous web forming one surface (A))
Polypropylene (PP) was melted in an extruder and spun out from a rectangular spinneret having a round hole with a hole diameter of φ of 0.4 mm at a single hole discharge rate of 0.8 g/min. After the spun yarn was cooled and solidified, it was drawn and stretched by compressed air in a rectangular ejector at a pressure of 0.08 MPa, and collected on a moving net to obtain a nonwoven fiber web. . The average single fiber diameter of the fibers constituting one surface (A) obtained was 20.4 μm.
　（他方の表面（Ｂ）を形成する繊維ウェブ）
　ポリプロピレンを押出機で溶融し、孔径が０．４ｍｍφの丸孔を有した矩形口金から、単孔吐出量が０．３ｇ／分で紡出した。紡出した糸条を、冷風にて冷却固化した後、矩形エジェクターにおいてエジェクターでの圧力を０．１２ＭＰａとした圧縮エアによって、牽引・延伸し、移動するネット上で、一方の表面（Ａ）を形成する繊維ウェブ上に捕集した。得られた他方の表面（Ｂ）を構成する繊維の平均単繊維直径は１０．６μｍであった。 (Fibrous web forming the other surface (B))
Polypropylene was melted in an extruder and spun out from a rectangular spinneret having round holes with a hole diameter of 0.4 mmφ at a single hole discharge rate of 0.3 g/min. After cooling and solidifying the spun yarn with cold air, it is pulled and stretched by compressed air in a rectangular ejector with the pressure at the ejector set to 0.12 MPa, and one surface (A) is exposed on the moving net. It was collected on the forming fibrous web. The average single fiber diameter of the fibers forming the other surface (B) obtained was 10.6 μm.
　（スパンボンド不織布）
　このようにして得た積層繊維ウェブを、上ロールには、図３－１のパターン１に示すように、長方形の凸部が形成する直線配列が直交して配置される格子柄の金属製エンボスロールを用い、下ロールに金属製フラットロールで構成される上下一対の加熱機構を有するエンボスロールを用いて、上ロール側を一方の表面（Ａ）を形成する繊維ウェブ、下ロール側を他方の表面（Ｂ）を形成する繊維ウェブとし、線圧が２００Ｎ／ｃｍで、熱融着温度が１３０℃の温度で熱融着し、目付が４０ｇ／ｍ２のスパンボンド不織布を得た。 (spunbond nonwoven)
The laminated fiber web obtained in this way was placed on the upper roll, as shown in pattern 1 in FIG. Using a roll, using an embossing roll having a pair of upper and lower heating mechanisms composed of a metal flat roll as the lower roll, the upper roll side is the fiber web forming one surface (A), and the lower roll side is the other A fibrous web forming the surface (B) was heat-sealed at a linear pressure of 200 N/cm and a heat-sealing temperature of 130° C. to obtain a spunbond nonwoven fabric having a basis weight of 40 g/m 2 .
　その後、親水加工として非イオン性界面活性剤をスパンボンド不織布重量に対して有効成分が０．５ｗｔ％となるよう、キスロールを用いて不織布に塗布した。 After that, as a hydrophilic treatment, a nonionic surfactant was applied to the nonwoven fabric using a kiss roll so that the active ingredient was 0.5 wt% with respect to the weight of the spunbond nonwoven fabric.
　得られたスパンボンド不織布の評価結果を表１に示す。 Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［実施例２］
　上ロールに、図３－２のパターン２に示すように、長方形の凸部が斜めに並んで形成する直線配列が直行して配置される格子柄のパターンの金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Example 2]
As shown in pattern 2 in FIG. 3-2, the upper roll uses a metal embossing roll with a lattice pattern in which linear arrays formed by obliquely aligning rectangular protrusions are arranged orthogonally. A spunbond nonwoven fabric was obtained in the same manner as in Example 1.
　得られたスパンボンド不織布の評価結果を表１に示す。 Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［実施例３］
　上ロールに、図３－３のパターン３に示すように、長方形の凸部が形成する直線配列が平行して配置されており、一部の間隔が広くなっているパターンの金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Example 3]
On the upper roll, as shown in pattern 3 in Fig. 3-3, a metal embossing roll with a pattern in which linear arrays formed by rectangular protrusions are arranged in parallel and some intervals are wide A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that it was used.
　得られたスパンボンド不織布の評価結果を表１に示す。 Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［実施例４］
　上ロールに、図３－４のパターン４に示すように、長方形の凸部が形成する直線配列が直交して配置されており、直線を形成する凸部間の距離がパターン１よりも近い格子柄のパターンの金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Example 4]
On the upper roll, as shown in pattern 4 in FIG. 3-4, linear arrays formed by rectangular protrusions are arranged orthogonally, and the distance between the protrusions forming the straight lines is closer than that of pattern 1. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that a patterned metal embossing roll was used.
　得られたスパンボンド不織布の評価結果を表１に示す。 Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［実施例５］
　親水加工として非イオン性界面活性剤をスパンボンド不織布重量に対して有効成分が０．３ｗｔ％となるよう、他方の表面（Ｂ）にのみスプレーを用いて不織布に塗布した以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Example 5]
Example 1 except that a nonionic surfactant was applied to the nonwoven fabric by spraying only on the other surface (B) so that the active ingredient was 0.3 wt% with respect to the weight of the spunbond nonwoven fabric as a hydrophilic treatment. A spunbond nonwoven fabric was obtained in the same manner as
　得られたスパンボンド不織布の評価結果を表１に示す。 Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例１］
　エンボスロールを用いた熱融着の代わりに、得られた繊維ウェブを１５０℃の熱風で加熱して熱融着した以外は実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 1]
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that instead of heat-sealing using an embossing roll, the obtained fiber web was heat-sealed with hot air at 150°C.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例２］
　一方の表面（Ａ）を構成する繊維ウェブと他方の表面（Ｂ）を構成する繊維、繊維ウェブのいずれも、単孔吐出量０．６ｇ／分として紡出し、矩形エジェクターにおけるエジェクターでの圧力を０．１０ＭＰａとした以外は実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 2]
Both the fiber web constituting one surface (A) and the fiber constituting the other surface (B) and the fiber web were spun at a single hole discharge rate of 0.6 g / min, and the pressure at the rectangular ejector was A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the pressure was 0.10 MPa.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例３］
　上ロール側を他方の表面（Ｂ）を形成する繊維ウェブ、下ロール側を一方の表面（Ａ）を形成する繊維ウェブとして熱接着した以外は実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 3]
A spunbond nonwoven fabric was obtained in the same manner as in Example 1 except that the upper roll side was a fiber web forming the other surface (B) and the lower roll side was thermally bonded as a fiber web forming one surface (A). rice field.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例４］
　上ロールに、図４－１のパターン５に示すように、長方形の凸部が形成する直線配列が直交して配置されており、直線を形成する凸部間の距離がパターン１よりも離れている格子柄のパターンの金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 4]
On the upper roll, as shown in pattern 5 in FIG. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that a metal embossing roll with a grid pattern was used.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例５］
　上ロールに、図４－２のパターン６に示すように、長方形の凸部が形成する直線配列が、２ｍｍの間隔で平行して配置されている金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 5]
As shown in pattern 6 in FIG. 4-2, the upper roll is a metal embossing roll in which linear arrays formed by rectangular protrusions are arranged in parallel at intervals of 2 mm. A spunbond nonwoven fabric was obtained in the same manner as in 1.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例６］
　上ロールに、図４－３のパターン７に示すように、４つの長方形の凸部が形成する配列がＭＤおよびＣＤの両方向に同じピッチで配置された金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 6]
For the upper roll, as shown in pattern 7 in FIG. A spunbond nonwoven fabric was obtained in the same manner as in Example 1.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例７］
　上ロールに、図４－４のパターン８に示すように、凸部の形状を正円形とした以外はパターン１と同様の配列とした金属製エンボスロールを用いた以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 7]
As shown in pattern 8 in FIG. 4-4, the same as in Example 1 except that a metal embossing roll with the same arrangement as pattern 1 except that the shape of the convex part is a perfect circle was used for the upper roll. A spunbond nonwoven fabric was obtained by the method of.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
　［比較例８］
　エンボスロールを用いて、線圧が１０Ｎ／ｃｍで熱融着した以外は、実施例１と同様の方法でスパンボンド不織布を得た。 [Comparative Example 8]
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1, except that an embossing roll was used and heat-sealed at a linear pressure of 10 N/cm.
　得られたスパンボンド不織布の評価結果を表２に示す。 Table 2 shows the evaluation results of the obtained spunbond nonwoven fabric.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　実施例１～５は、平均単繊維直径比（Ｄａ／Ｄｂ）が大きく、一方の表面（Ａ）の繊維と他方の表面（Ｂ）の繊維がともに融着している場所を有しており、かつ、融着部が特定の形状および配列に制御されているため、優れたドライ性と、優れた速乾性を有していることが分かる。 Examples 1 to 5 have a large average single fiber diameter ratio (Da/Db) and have locations where the fibers on one surface (A) and the fibers on the other surface (B) are fused together. Moreover, since the fused portion is controlled to have a specific shape and arrangement, it is found to have excellent dryness and quick drying properties.
　一方、比較例１は、一方の表面（Ａ）の繊維と他方の表面（Ｂ）の繊維がともに融着している場所を有していないため、面内への水の移動を生じにくく、ドライ性および速乾性が劣っている。また、比較例２は、平均単繊維直径比が小さいため不織布内で水分が他方の表面（Ｂ）側に移行されず、ドライ性および速乾性に劣る。比較例３は、融着部が表面（Ｂ）側から一方の表面（Ａ）側に形成されることにより他方の表面（Ｂ）側の繊維間空隙サイズが拡張したため、不織布内で水分が他方の表面（Ｂ）側に移行されにくく、ドライ性および速乾性に劣るものであった。 On the other hand, in Comparative Example 1, since there is no place where the fibers on one surface (A) and the fibers on the other surface (B) are fused together, it is difficult for water to move in the plane, Poor dryness and fast drying. In Comparative Example 2, since the average single fiber diameter ratio is small, moisture is not transferred to the other surface (B) side in the nonwoven fabric, and the dryness and quick drying properties are poor. In Comparative Example 3, since the fused portion was formed from the surface (B) side to the one surface (A) side, the void size between the fibers on the other surface (B) side was expanded, so that the moisture inside the nonwoven fabric was reduced to the other side. It was difficult to migrate to the surface (B) side of , and was inferior in dryness and quick drying properties.
　比較例４は、非融着部の最小内接円の直径が大きいため、融着部間での水移動が弱く、面内での水の拡散が生じにくいため、速乾性に劣る。また、比較例５は、最大内接円直径が小さいため、非融着部に水が残留しやすく、速乾性に劣る。比較例６は、融着部が直線的につながっていないため、面内での水拡散ができず、速乾性に劣る。また、比較例７は、融着部の異形度が小さいため、融着部での融着部間での水移動が弱く、面内での水の拡散が生じにくいため、速乾性に劣るものであった。 In Comparative Example 4, since the diameter of the minimum inscribed circle of the non-fused portion is large, the movement of water between the fused portions is weak, and diffusion of water within the surface is difficult to occur, resulting in poor quick-drying properties. Further, in Comparative Example 5, since the maximum inscribed circle diameter is small, water tends to remain in the non-fused portion, resulting in poor quick-drying properties. In Comparative Example 6, since the fused portion is not linearly connected, water cannot diffuse in the plane, resulting in poor quick-drying properties. In addition, in Comparative Example 7, since the degree of irregularity of the fused portions is small, water movement between the fused portions is weak, and diffusion of water within the surface is difficult to occur, resulting in poor quick-drying properties. Met.
　また、比較例８では、融着部周囲の繊維密度が大きくなり、非融着部からの導水が行われず、面内での水拡散が行われないため、速乾性に劣るものであった。 In addition, in Comparative Example 8, the fiber density around the fused portion was increased, water was not conveyed from the non-fused portion, and water diffusion in the plane was not performed, resulting in poor quick-drying properties.
　本発明のスパンボンド不織布は、衛生材料として好適に用いることができる。本発明の衛生材料は、優れた吸水性、ドライ性および速乾性が得られるものである。なお、本発明の衛生材料は、医療・介護など健康に関わる目的で使用される、主に使い捨ての物品であり、紙おむつ、生理用ナプキン、ガーゼ、包帯、マスク、手袋、絆創膏等が挙げられ、その構成部材、例えば、紙おむつのトップシート、バックシート、サイドギャザー等も含まれる。中でも、以下の態様が好適な態様として挙げられる。 The spunbond nonwoven fabric of the present invention can be suitably used as a sanitary material. The sanitary material of the present invention provides excellent water absorption, dryness and quick drying properties. The sanitary material of the present invention is mainly a disposable article used for health-related purposes such as medical care and nursing care, and includes disposable diapers, sanitary napkins, gauze, bandages, masks, gloves, adhesive bandages, etc. Its constituent members, for example, the top sheet, back sheet, side gathers, etc. of disposable diapers are also included. Among them, the following aspects are mentioned as preferable aspects.
　第１の好適な実施態様としては、トップシートが前記のスパンボンド不織布で構成されてなる、おむつである。特に前記のスパンボンド不織布を、前記一方の表面（Ａ）がおむつのトップシートの肌面側として設置されるように用いた場合には、***された尿を素早く吸収し、前記他方の表面（Ｂ）に迅速に液が移行されるため、スパンボンド不織布の表面をドライに保つことができる。 A first preferred embodiment is a diaper in which the topsheet is composed of the above spunbond nonwoven fabric. In particular, when the spunbond nonwoven fabric is used so that the one surface (A) is placed as the skin surface side of the top sheet of the diaper, it quickly absorbs excreted urine and the other surface (A) Since the liquid is quickly transferred to B), the surface of the spunbond nonwoven fabric can be kept dry.
　第２の好適な実施態様としては、ウエスト部の一部が前記スパンボンド不織布で構成されてなる、おむつである。特に前記のスパンボンド不織布を、前記一方の表面（Ａ）がおむつのトップシートウエスト部の肌面側として設置されるように用いた場合には、汗を素早く吸収し、前記他方の表面（Ｂ）に迅速に液が移行されるため、スパンボンド不織布の表面をドライに保つことができる。 A second preferred embodiment is a diaper in which a part of the waist portion is made of the spunbond nonwoven fabric. In particular, when the spunbond nonwoven fabric is used so that the one surface (A) is placed as the skin side of the top sheet waist portion of the diaper, it quickly absorbs sweat and the other surface (B ), the surface of the spunbond nonwoven fabric can be kept dry.
　第３の好適な実施態様としては、内面層が前記のスパンボンド不織布で構成されてなる、マスクである。本発明でいう内面層とは、口を覆う面体のうち、最も口側に設置される層のことを指す。前記のスパンボンド不織布を、前記一方の表面（Ａ）が肌面側として設置されるように用いた場合には、汗や呼気が結露し、肌面側に水分が付着しても、スパンボンド不織布内部にすぐに吸収され、肌面をドライに保つことができるため、着用した際の不快感がなく、好ましい使用用途として挙げられる。 A third preferred embodiment is a mask in which the inner surface layer is composed of the above spunbond nonwoven fabric. The term "inner layer" as used in the present invention refers to the layer of the face piece covering the mouth that is located closest to the mouth. When the spunbond nonwoven fabric is used so that the one surface (A) is placed on the skin side, even if sweat or exhalation condenses and moisture adheres to the skin side, the spunbond Since it is quickly absorbed into the nonwoven fabric and keeps the skin dry, there is no discomfort when worn, and it is a preferred application.
　１：スパンボンド不織布
　１１：融着部
　１２：非融着部
　１３：非融着部の最小内接円
　１４：非融着部の最大内接円
　２１～２４：近接する融着部
　Ｍ１～Ｍ４：融着部２１～２４それぞれの幾何学的重心点
　Ｌ１２：Ｍ１とＭ２を結んだ線分
　Ｌ２３：Ｍ２とＭ３を結んだ線分
　Ｌ３４：Ｍ３とＭ４を結んだ線分 1: spunbond nonwoven fabric 11: fused portion 12: non-fused portion 13: minimum inscribed circle of non-fused portion 14: maximum inscribed circle of non-fused portion 21-24: adjacent fused portions M1-M4 : Geometric center of gravity of each of the fused parts 21 to 24 L12: Line segment connecting M1 and M2 L23: Line segment connecting M2 and M3 L34: Line segment connecting M3 and M4

Claims (11)

  1. 　融着部と非融着部とを有し、一方の表面（Ａ）において、融着部が他方の表面（Ｂ）に向かう凹部を形成しており、前記一方の表面（Ａ）を構成する繊維の平均単繊維直径（Ｄａ）の、他方の表面（Ｂ）を構成する繊維の平均単繊維直径（Ｄｂ）に対する比（Ｄａ／Ｄｂ）が１．１以上であって、以下の条件を満たすスパンボンド不織布。
    　(1)前記非融着部の最小内接円の直径が１．０ｍｍ以下である
    　(2)前記非融着部の最大内接円の直径が２．０ｍｍ以上である
    　(3)前記融着部が列状に連なって配置されている
    　(4)前記融着部におけるスパンボンド不織布の厚み（Ｔｍ）とスパンボンド不織布の厚み（Ｔ）との比（Ｔｍ／Ｔ）が、０．３０以下である
    　(5)前記融着部の異形度が１．１以上である     It has a fused portion and a non-fused portion, and on one surface (A), the fused portion forms a recess facing the other surface (B), and constitutes the one surface (A). The ratio (Da/Db) of the average single fiber diameter (Da) of the fibers to the average single fiber diameter (Db) of the fibers constituting the other surface (B) is 1.1 or more, and satisfies the following conditions: Spunbond nonwoven fabric.
    (1) The diameter of the minimum inscribed circle of the unfused portion is 1.0 mm or less (2) The diameter of the maximum inscribed circle of the unfused portion is 2.0 mm or more (3) The fused portion (4) The ratio (Tm/T) of the thickness (Tm) of the spunbond nonwoven fabric to the thickness (T) of the spunbond nonwoven fabric in the fused portion is 0.30 or less. (5) The fused portion has an irregularity of 1.1 or more.
  2. 　前記非融着部の最大内接円の直径が１０．０ｍｍ以下である請求項１に記載のスパンボンド不織布。 The spunbond nonwoven fabric according to claim 1, wherein the diameter of the maximum inscribed circle of the non-fused portion is 10.0 mm or less.
  3. 　前記融着部が間欠的に配置されている請求項１または請求項２のいずれかに記載のスパンボンド不織布。 The spunbond nonwoven fabric according to claim 1 or claim 2, wherein the fused parts are arranged intermittently.
  4. 　前記非融着部の最小内接円の直径が０．２ｍｍ以上である請求項１～３のいずれかに記載のスパンボンド不織布。 The spunbond nonwoven fabric according to any one of claims 1 to 3, wherein the diameter of the minimum inscribed circle of the non-fused portion is 0.2 mm or more.
  5. 　前記一方の表面（Ａ）および前記他方の表面（Ｂ）の、水との接触角がともに３０°以下である請求項１～４のいずれかに記載のスパンボンド不織布。 The spunbond nonwoven fabric according to any one of claims 1 to 4, wherein both the one surface (A) and the other surface (B) have contact angles with water of 30° or less.
  6. 　請求項１～５のいずれかに記載のスパンボンド不織布で少なくとも一部が構成されてなる衛生材料。 A sanitary material at least partially composed of the spunbond nonwoven fabric according to any one of claims 1 to 5.
  7. 　前記衛生材料がおむつである請求項６記載の衛生材料。 The sanitary material according to claim 6, wherein the sanitary material is a diaper.
  8. 　前記少なくとも一部がトップシートである請求項７記載の衛生材料。 The sanitary material according to claim 7, wherein said at least part is a topsheet.
  9. 　前記少なくとも一部がウエスト部の少なくとも一部である請求項７記載の衛生材料。 The sanitary material according to claim 7, wherein said at least part is at least part of the waist portion.
  10. 　前記衛生材料がマスクである請求項６記載の衛生材料。 The sanitary material according to claim 6, wherein the sanitary material is a mask.
  11. 　前記少なくとも一部がマスクの内面層である請求項１０記載の衛生材料。 The sanitary material according to claim 10, wherein said at least part is an inner surface layer of a mask.
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