Nonwoven cloth, nonwoven cloth laminate, and sanitary article

Abstract

To provide a nonwoven cloth having both suppression of bleed through of an adhesive constituent and feeling.SOLUTION: A nonwoven cloth includes a fiber of a thermoplastic resin, where the irregular shape degree ratio (irregular shape degree A / irregular shape degree B) of an irregular shape degree (R / r, irregular shape degree A) defined by a diameter R of a circumcircle to a cross section orthogonal to a lengthwise direction of a single fiber of a fiber of a place which is not emboss-processed on one side face of the emboss-processed nonwoven cloth, and a diameter r of an incircle to a cross section orthogonal to a lengthwise direction of the single fiber of the fiber to an irregular shape degree (irregular shape degree B) of a fiber of a place which is not emboss-processed on another face of the nonwoven cloth is 1.5-2.5.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to nonwoven fabrics, nonwoven fabric laminates, and sanitary products.

Background Art

[0002] Nonwoven fabrics made of polyolefin (e.g., polypropylene) are excellent in air permeability, texture, etc., and thus are used as materials constituting sanitary products such as disposable diapers and sanitary napkins. When manufacturing sanitary products, in the process of bonding nonwoven fabrics to each other or nonwoven fabrics to other members using an adhesive component such as a hot melt adhesive, the adhesive component may penetrate the nonwoven fabric and seep through, contaminating the production line. In order to suppress the seepage of the hot melt adhesive, Patent Document 1 discloses a long fiber nonwoven fabric made of a thermoplastic resin, wherein the contact area ratio on at least one surface of the nonwoven fabric is 30% or more and 60% or less, and the minimum unevenness ratio with respect to the nonwoven fabric thickness is 15% or more and 50% or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the long fiber nonwoven fabric described in Patent Document 1 has a rough and dense structure in which single filaments are separated in the non-embossed portion, so there is a possibility that the adhesive component may seep through from the low-density portion. Even with the long fiber nonwoven fabric described in Patent Document 1, it may not be possible to sufficiently suppress the seepage of the adhesive component. The present disclosure has been made in view of the above conventional circumstances, and an object thereof is to provide a nonwoven fabric and a nonwoven fabric laminate in which suppression of seepage of an adhesive component and texture are compatible, and a sanitary product using the same.

Means for Solving the Problem

[0005] The specific means for achieving the above problem are as follows. <1> A non-woven fabric containing fibers of a thermoplastic resin and embossed, For the fibers at the unembossed portion on one surface of the non-woven fabric, the degree of irregularity (degree of irregularity A) defined by the following formula, and for the fibers at the unembossed portion on the other surface of the non-woven fabric, the degree of irregularity (degree of irregularity B) defined by the following formula, a non-woven fabric in which the degree of irregularity ratio (degree of irregularity A / degree of irregularity B) is 1.5 to 2.5. Degree of irregularity = R / r (formula) (In the above formula, R refers to the diameter of the circumscribed circle with respect to the cross-section orthogonal to the longitudinal direction of the single fiber of the fiber, and r refers to the diameter of the inscribed circle with respect to the cross-section orthogonal to the longitudinal direction of the single fiber of the fiber.) <2> The non-woven fabric according to <1>, wherein the fibers of the thermoplastic resin contain polyolefin. <3> The non-woven fabric according to <1> or <2>, wherein the fibers of the thermoplastic resin are hollow fibers. <4> The basis weight is 5 g / m 2 ~20 g / m 2 The non-woven fabric according to any one of <1> to <3>. <5> The air permeability is 30 cm 3 / cm 2 / sec to 300 cm 3 / cm 2 / sec The non-woven fabric according to any one of <1> to <4>. <6> A non-woven fabric laminate including a non-woven fabric layer which is the non-woven fabric according to any one of <1> to <5>. <7> A non-woven fabric laminate including at least two non-woven fabric layers containing fibers of a thermoplastic resin and embossed, A nonwoven fabric laminate in which the ratio of the degree of irregularity (degree of irregularity A) defined by the following formula for the fibers at the unembossed portion on one surface of the nonwoven fabric laminate to the degree of irregularity (degree of irregularity B) defined by the following formula for the fibers at the unembossed portion on the other surface of the nonwoven fabric laminate (degree of irregularity A / degree of irregularity B) is 1.5 to 2.5. Degree of irregularity = R / r (formula) (In the above formula, R refers to the diameter of the circumscribed circle with respect to the cross-section orthogonal to the length direction of the single fiber of the fiber, and r refers to the diameter of the inscribed circle with respect to the cross-section orthogonal to the length direction of the single fiber of the fiber.) <8> The nonwoven fabric laminate according to <7>, wherein the fibers of the thermoplastic resin contain polyolefin. <9> The nonwoven fabric laminate according to <7> or <8>, wherein the fibers of the thermoplastic resin contained in at least one layer of the nonwoven fabric layer are hollow fibers. <10> The basis weight is 5 g / m 2 ~20 g / m 2 and is the nonwoven fabric laminate according to any one of <7> to <9>. <11> The air permeability is 30 cm 3 / cm 2 / sec to 300 cm 3 / cm 2 / sec and is the nonwoven fabric laminate according to any one of <7> to <10>. <12> The nonwoven fabric laminate according to any one of <7> to <11>, wherein the nonwoven fabric layer located on the surface on one side of the nonwoven fabric laminate and the nonwoven fabric layer located on the surface on the other side are both spunbond nonwoven fabric layers. <13> The nonwoven fabric laminate according to <12>, further comprising a meltblown nonwoven fabric layer as an intermediate layer. <14> A sanitary product having the nonwoven fabric according to any one of <1> to <5> or the nonwoven fabric laminate according to any one of <6> to <13>.

Advantages of the Invention

[0006] According to the present disclosure, it is possible to provide a nonwoven fabric and a nonwoven fabric laminate in which suppression of bleeding-through of the adhesive component and texture are compatible, and a sanitary product using these.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0008] Hereinafter, the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, which do not limit the present disclosure.

[0009] In the present disclosure, the term "step" includes, in addition to steps independent of other steps, the step even if it cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. In the numerical range indicated by "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, the terms "layer" or "film" include not only the case where it is formed over the entire area when observing the area where the layer or film is present, but also the case where it is formed only in a part of the area. In the present disclosure, the term "lamination" indicates stacking layers, and two or more layers may be bonded, and two or more layers may be detachable.

[0010] <Nonwoven fabric> The nonwoven fabric of the present disclosure contains fibers of a thermoplastic resin and is an embossed nonwoven fabric, and the degree of irregularity (degree of irregularity A) defined by the following formula for the fibers at the unembossed portion on one surface of the nonwoven fabric and the degree of irregularity (degree of irregularity B) defined by the following formula for the fibers at the unembossed portion on the other surface of the nonwoven fabric have an irregularity ratio (degree of irregularity A / degree of irregularity B) of 1.5 to 2.5. Degree of irregularity = R / r (formula) In the above formula, R refers to the diameter of the circumscribed circle with respect to the cross-section orthogonal to the longitudinal direction of the single fiber of the fiber, and r refers to the diameter of the inscribed circle with respect to the cross-section orthogonal to the longitudinal direction of the single fiber of the fiber. According to the nonwoven fabric of the present disclosure, suppression of bleeding of the adhesive component and texture are compatible. The reason is not clear, but it is presumed as follows.

[0011] FIG. 1 is a diagram showing a cross-section orthogonal to the longitudinal direction of a single fiber of a fiber (hereinafter, may be referred to as a single-fiber cross-section), FIG. 1(A) is a single-fiber cross-section of a fiber showing the degree of irregularity A, and FIG. 1(B) is a single-fiber cross-section of a fiber showing the degree of irregularity B. The degree of irregularity A of the single fiber 10A of the fiber shown in FIG. 1(A) is the diameter R of the circumscribed circle represented by the dashed line tangent to the single-fiber cross-section of the single fiber 10A Aand the diameter r of the inscribed circle represented by a two-dot chain line inscribed in the cross-section of the single fiber 10A A Based on A R A is defined by The degree of deformation B of the single fiber 10B of the fiber shown in Fig. 1(B) is the diameter R of the circumscribed circle represented by a one-dot chain line circumscribing the cross-section of the single fiber 10B B and the diameter r of the inscribed circle represented by a two-dot chain line inscribed in the cross-section of the single fiber 10B B Based on B R B is defined by The cross-section of the single fiber of the fiber with a relatively large degree of deformation tends to be flatter than the cross-section of the single fiber of the fiber with a relatively small degree of deformation. For example, the degree of deformation of the single fiber 10A of the fiber shown in Fig. 1(A) is larger than the degree of deformation of the single fiber 10B of the fiber shown in Fig. 1(B), and it can be seen that the cross-section of the single fiber 10A has a flatter shape compared to the cross-section of the single fiber 10B. It is presumed that the presence of fibers with flat single fiber cross-sections on one surface of the nonwoven fabric results in a dense structure on the surface of that surface, suppressing the penetration of the adhesive component in the thickness direction of the nonwoven fabric. On the other hand, it is presumed that the texture required for the nonwoven fabric is ensured on the other surface of the nonwoven fabric.

[0012] In the present disclosure, the degree of deformation ratio of the nonwoven fabric refers to a value calculated according to the following method from the obtained cross-sectional photograph by photographing a cross-sectional photograph of the nonwoven fabric with a magnification of 300 to 1000 times (for example, 600 times) using a scanning electron microscope. Fig. 2 shows an example of a cross-sectional photograph of a nonwoven fabric taken with a magnification of 300 times using a scanning electron microscope. In the unembossed portion of the single fiber constituting the nonwoven fabric, for the single fiber exposed on the surface of one surface of the nonwoven fabric and having a cross-sectional cut surface perpendicular to the length direction visible, the diameter (R A ) of the circumscribed circle and the diameter (r A ) of the inscribed circle are obtained, and the degree of deformation A (R A / r A ) is calculated from the obtained values. In addition, in the unembossed portion of the single filaments constituting the nonwoven fabric, for the single filaments exposed on the surface on the side opposite to one surface of the nonwoven fabric (i.e., the other surface), the diameter (R B ) of the circumscribed circle of the single filaments where the cross-sectional cut perpendicular to the length direction is visible, and the diameter (r B ) of the inscribed circle are obtained, and the degree of irregularity B (R B / r B ) is calculated from the obtained values. In the present disclosure, 10 single filaments are arbitrarily selected from each surface of the nonwoven fabric, the average value of the degree of irregularity A and the average value of the degree of irregularity B are obtained, and the degree of irregularity ratio is calculated from the following formula. Degree of irregularity ratio = average value of degree of irregularity A / average value of degree of irregularity B Note that one surface and the other surface are set such that the degree of irregularity A for one surface and the degree of irregularity B for the other surface satisfy the relationship of degree of irregularity A ≥ degree of irregularity B. One surface may be the surface that has been surface-treated so that the cross-section of the single filaments becomes a flat shape by the calendar treatment described later.

[0013] The nonwoven fabric of the present disclosure has a degree of irregularity ratio of 1.5 to 2.5. The degree of irregularity ratio is 1.5 or more from the viewpoint of suppressing the penetration of the adhesive component, preferably 1.6 or more, more preferably 1.8 or more. The degree of irregularity ratio is 2.5 or less from the viewpoint of texture, preferably 2.3 or less, more preferably 2.1 or less. The nonwoven fabric of the present disclosure preferably has a degree of irregularity ratio of 1.6 to 2.3, more preferably 1.8 to 2.1.

[0014] For the degree of irregularity A of one surface of the nonwoven fabric of the present disclosure, from the viewpoint of preventing the adhesive component from oozing out, it is preferably 1.8 or more, more preferably 2.0 or more, and even more preferably 2.2 or more. From the viewpoint of strength, the degree of irregularity A is preferably 3.5 or less, more preferably 3.2 or less, and even more preferably 3.0 or less. For the degree of irregularity A of one surface of the nonwoven fabric of the present disclosure, 1.8 to 3.5 is preferable, 2.0 to 3.2 is more preferable, and 2.2 to 3.0 is even more preferable. For the irregularity B of the other side of the nonwoven fabric of the present disclosure, from the viewpoint of the penetration of the adhesive component, it is preferably 1.1 or more, more preferably 1.2 or more, and even more preferably 1.3 or more. From the viewpoint of texture, the irregularity B is preferably 1.8 or less, more preferably 1.7 or less, and even more preferably 1.6 or less. For the irregularity B of the other side of the nonwoven fabric of the present disclosure, 1.1 to 1.8 is preferable, 1.2 to 1.7 is more preferable, and 1.3 to 1.6 is even more preferable.

[0015] Hereinafter, the components constituting the nonwoven fabric of the present disclosure, the physical properties of the nonwoven fabric of the present disclosure, etc. will be specifically described. The nonwoven fabric of the present disclosure contains fibers of a thermoplastic resin. The thermoplastic resin constituting the fiber is not particularly limited, and includes homopolymers or copolymers of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene (hereinafter, the homopolymer or copolymer of α-olefin may be referred to as "polyolefin"), polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamides such as nylon-6, nylon-66, polymetaxylylene adipamide, polyvinyl chloride, polyimide, ethylene-vinyl acetate copolymer, polyacrylonitrile, polycarbonate, polystyrene, ionomer, etc. Among these, the fibers of the thermoplastic resin preferably contain polyolefin from the viewpoints of heat resistance and flexibility. The thermoplastic resin may consist of one kind or may be a mixture of two or more kinds. The proportion of polyolefin in the thermoplastic resin contained in the fibers of the thermoplastic resin is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 99% by mass or more.

[0016] Examples of polyolefins include ethylene polymers such as ethylene-propylene random copolymers, high-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), high-density polyethylene, and ethylene random copolymers such as ethylene-1-butene random copolymers; propylene polymers such as polypropylene (propylene homopolymer), propylene-ethylene random copolymers, and propylene-1-butene random copolymers; poly-1-butene, poly-4-methyl-1-pentene, and the like.

[0017] The thermoplastic resin preferably contains at least one selected from the group consisting of high-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), high-density polyethylene, propylene polymers, polyethylene terephthalate, and polyamide. From the viewpoint of excellent spinnability, drawability, etc., the thermoplastic resin preferably contains a propylene polymer. The proportion of the propylene polymer in the thermoplastic resin contained in the fiber of the thermoplastic resin is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and particularly preferably 99% by mass or more.

[0018] Examples of the propylene polymer include propylene homopolymers and propylene random copolymers which are copolymers of propylene as the main component and one or more α-olefins as the sub-components. Among them, propylene homopolymers are preferred. In the propylene random copolymer, the content of the structural unit derived from the α-olefin is preferably 1 mol% to 10 mol% of the whole, and more preferably 1 mol% to 6 mol% of the whole.

[0019] As the α-olefin used for copolymerization of the propylene random copolymer, α-olefins having 2 or more carbon atoms (excluding propylene) are preferred, and α-olefins having 2 or 4 to 8 carbon atoms are more preferred. Specific examples of the α-olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, etc.

[0020] The melting point (Tm) of the propylene-based polymer is not particularly limited, and for example, it may be 125°C or higher, or may be 125°C to 165°C.

[0021] In the present disclosure, the melting point can be measured as follows using differential scanning calorimetry (DSC). Using a differential scanning calorimeter (DSC), DSC Pyris1 manufactured by PerkinElmer or DSC7020 manufactured by SII NanoTechnology Inc., under a nitrogen atmosphere (20 mL / min), the sample (about 5 mg) is heated to the reaching temperature set for each thermoplastic resin (230°C in the case of the propylene-based polymer), held at that temperature for 3 minutes, then cooled to 30°C at 10°C / min and held at 30°C for 1 minute, and then heated to the above reaching temperature at 10°C / min. The melting point (Tm) is calculated from the peak top of the crystal melting peak in the heating process. When multiple crystal melting peaks are observed, the peak on the high-temperature side is taken as the melting point (Tm).

[0022] When using a propylene-α-olefin random copolymer as the propylene-based polymer, its melting point (Tm) is preferably 153°C or lower, and more preferably 125°C to 150°C. When using a propylene homopolymer as the propylene-based polymer, its melting point (Tm) is preferably 155°C or higher, and more preferably 157°C to 165°C.

[0023] The melt flow rate (MFR) (ASTM D-1238, 230 °C, load 2160 g) of the propylene-based polymer is not particularly limited as long as a nonwoven fabric can be produced. For example, it is preferably 10 g / 10 min to 100 g / 10 min, and more preferably 20 g / 10 min to 70 g / 10 min. When a propylene-based polymer with an MFR of 10 g / 10 min or more is used, the melt viscosity is low and the spinnability tends to improve. On the other hand, when a propylene-based polymer with an MFR of 100 g / 10 min or less is used, the tensile strength of the resulting nonwoven fabric and the like tend to improve.

[0024] The propylene-based polymer is usually obtained by slurry polymerization, gas-phase polymerization, or bulk polymerization using a Ziegler-Natta catalyst that combines a so-called titanium-containing solid transition metal component and an organometallic component, or a metallocene catalyst composed of a transition metal compound of Groups 4 to 6 of the periodic table having at least one cyclopentadienyl skeleton and a cocatalyst component, by homopolymerizing propylene or copolymerizing propylene with a small amount of α-olefin.

[0025] Also, the fibers contained in the nonwoven fabric of the present disclosure may be composite fibers containing two or more thermoplastic resins. Examples of the composite fibers include sea-island type, side-by-side type, concentric core-sheath type, and eccentric core-sheath type. The eccentric core-sheath type composite fiber may be an exposed type in which the core portion is exposed on the surface or a non-exposed type in which the core portion is not exposed on the surface.

[0026] Additives such as antioxidants, weather stabilizers, light stabilizers, antistatic agents, hydrophilic agents, antifogging agents, antiblocking agents, lubricants, nucleating agents, pigments, or other polymers can be blended into the thermoplastic resin as needed within a range that does not impair the object of the present disclosure.

[0027] In the present disclosure, the "nonwoven fabric" refers to a fiber aggregate in which fibers are entangled and fused to each other to form a sheet. Specifically, when observed with an electron microscope (magnification: ×500), the total area is 0.2 mm 2When the number of fiber-to-fiber fusion points is 50 or more within the range, it is called a "nonwoven fabric". On the other hand, when the number of fiber-to-fiber fusion points is less than 50, it is called "fluffy" and is distinguished from "nonwoven fabric".

[0028] The type of nonwoven fabric is not particularly limited, and various known short fiber nonwoven fabrics and long fiber nonwoven fabrics (for example, long fiber cellulose nonwoven fabric) such as spunbond nonwoven fabric, meltblown nonwoven fabric, wet nonwoven fabric, spunlace nonwoven fabric, dry nonwoven fabric, dry pulp nonwoven fabric, airlaid nonwoven fabric, waterjet nonwoven fabric, flash spun nonwoven fabric, fibrillated nonwoven fabric, needle punched nonwoven fabric, etc. can be mentioned.

[0029] From the viewpoint of productivity, the nonwoven fabric of the present disclosure is preferably composed of long fibers. In the present disclosure, "short fiber" refers to fibers having an average fiber length of 200 mm or less. Also, "long fiber" refers to fibers having an average fiber length exceeding 200 mm.

[0030] The fibers of the thermoplastic resin contained in the nonwoven fabric of the present disclosure may be hollow fibers or solid fibers, and from the viewpoint that the degree of deformation ratio can be easily adjusted by the calendar treatment described later, it is preferably a hollow fiber, and more preferably a spunbond nonwoven fabric made of hollow fibers. When the fibers of the thermoplastic resin contained in the nonwoven fabric of the present disclosure are hollow fibers, the hollowness ratio of the hollow fibers is not particularly limited, and from the viewpoints of light weight and tensile strength, it is preferably 5% to 30%, more preferably 10% to 30%, and even more preferably 14% to 30%.

[0031] The hollowness ratio of the hollow fiber can be determined as follows. Embed the nonwoven fabric in an epoxy resin, then cut it with a microtome to obtain a sample piece. Observe this with an electron microscope (for example, S-3500N type, scanning electron microscope manufactured by Hitachi, Ltd.), and determine the cross-sectional area of the entire fiber and the cross-sectional area of the hollow part in the fiber cross-sectional image observed from the obtained cross-sectional image, and calculate from the following formula. Hollowness ratio [%] = (Cross-sectional area of hollow part / Cross-sectional area of entire fiber) × 100 Note that the value of the hollowness ratio is the average value measured for 100 hollow fibers.

[0032] The C-axis orientation degree of the hollow fibers contained in the nonwoven fabric of the present disclosure is not particularly limited, and from the viewpoint of the uniformity of the nonwoven fabric, it is preferably 0.85 or more, and more preferably 0.90 or more. The upper limit of the C-axis orientation degree of the hollow fibers is not particularly limited, and for example, it may be 0.95 or less.

[0033] The C-axis orientation degree of the hollow fibers can be obtained as follows. Using a wide-angle X-ray diffractometer (for example, RINT2550 manufactured by Rigaku Corporation, accessory device: fiber sample stage, X-ray source: CuKα, output: 40 kV 370 mA, detector: scintillation counter), arrange the nonwoven fabric in the fiber axis direction and fix it to the sample holder. In the azimuthal distribution curve (X-ray interference diagram) obtained by measuring the azimuthal distribution intensity of the crystal plane peak [(110) plane], the orientation degree (C-axis orientation degree) of the fiber axis direction of the hollow fibers is calculated from the following formula using the half-width (α) of the peak. Orientation degree (F) = (180° - α) / 180° (α is the half-width of the peak in the azimuthal distribution curve)

[0034] The hollow fibers contained in the nonwoven fabric may have an eccentric hollow part. For example, it may be an eccentric hollow fiber in which the center position of the hollow part in the single fiber cross section of the hollow fiber is different from the center position of the single fiber cross section. The eccentric hollow fiber may have the fiber curled.

[0035] The average fiber diameter of the fibers contained in the nonwoven fabric of the present disclosure is not particularly limited, and from the viewpoints of light weight and tensile strength, it is preferably 5 μm to 20 μm, and more preferably 5 μm to 17 μm.

[0036] The average fiber diameter of the fibers can be obtained as follows. Observe the nonwoven fabric with an optical microscope (for example, ECLIPSE E-400 manufactured by Nikon Corporation), select 100 fibers from the fibers forming the nonwoven fabric on the screen and measure their fiber diameters, and take the average value as the average fiber diameter of the nonwoven fabric.

[0037] The thickness of the nonwoven fabric is preferably 0.5 mm or less, more preferably 0.005 mm to 0.5 mm, even more preferably 0.01 mm to 0.3 mm, and particularly preferably 0.02 mm to 0.2 mm. The smaller the thickness, the more capable it is of capturing small particles and the thinner it can be when used as a filter.

[0038] The thickness of the nonwoven fabric can be determined as follows. For 10 nonwoven fabrics to be measured, measure the thickness at a total of 5 locations including the center and the four corners, and average these values to obtain the thickness for each nonwoven fabric. Calculate the average value of the thicknesses of the 10 nonwoven fabrics, and use this as the thickness of the nonwoven fabric. For measuring the thickness, use a thickness gauge with a load of 7 gf / cm 2 (probe diameter 25 mmφ).

[0039] From the perspective of air permeability, the air permeability of the nonwoven fabric is preferably 30 cm 3 / cm 2 / sec or more, more preferably 50 cm 3 / cm 2 / sec or more, even more preferably 80 cm 3 / cm 2 / sec or more. From the perspective of the penetration of the adhesive component, the air permeability of the nonwoven fabric is preferably 300 cm 3 / cm 2 / sec or less, more preferably 250 cm 3 / cm 2 / sec or less, even more preferably 180 cm 3 / cm 2 / sec or less. The air permeability of the nonwoven fabric is preferably 30 cm 3 / cm 2 / sec to 300 cm 3 / cm 2 / sec. In the present disclosure, the air permeability refers to the value obtained by measuring the flow rate at a pressure difference of 125 Pa using a Frazier air permeability measuring machine in accordance with JIS L 1096 (2010).

[0040] From the perspective of flexibility, the basis weight of the nonwoven fabric is 20 g / m 2It is preferably as follows, 17 g / m 2 It is more preferably as follows, 15 g / m 2 It is even more preferably as follows. Further, from the viewpoint of improving the rewettability resistance, the basis weight is preferably 5 g / m 2 or more, more preferably 7 g / m 2 or more, and even more preferably 8 g / m 2 or more. The basis weight of the nonwoven fabric is 5 g / m 2 ~20 g / m 2 is preferable.

[0041] The nonwoven fabric of the present disclosure may contain additives such as commonly used antioxidants, weather stabilizers, light stabilizers, antistatic agents, hydrophilic agents, antifogging agents, antiblocking agents, lubricants, nucleating agents, and pigments, as long as the object of the present disclosure is not impaired. These additives may be blended as necessary with the thermoplastic resin that can be used in manufacturing the nonwoven fabric of the present disclosure.

[0042] Hereinafter, the manufacturing method of the nonwoven fabric of the present disclosure in the case where it is a spunbond nonwoven fabric containing hollow fibers will be described.

[0043] The spunbond nonwoven fabric containing hollow fibers can be manufactured by a closed-type spunbond process shown in, for example, JP-A-60-155765, Patent No. 3442896, and Patent No. 3883818.

[0044] The spunbond nonwoven fabric containing hollow fibers is manufactured by, for example, the spunbond nonwoven fabric manufacturing apparatus shown in Fig. 7. The spunbond nonwoven fabric manufacturing apparatus shown in Fig. 7 includes an extruder 1, a spinneret 2, a diffuser 5, a capturing device 6, and a suction device 7. The hollow fibers 3 spun from the spinneret 2 are cooled by the cooling air 4 in the sealed cooling chamber. After the hollow fibers 3 are cooled, they are drawn (traction) by the stretching air through a constriction (stretching part) for using the cooling air used for cooling as stretching air on the downstream side of the cooling chamber, and the fibers are dispersed by the diffuser 5 installed on the downstream side and deposited on the moving collection surface (on the mesh belt), and the spunbond nonwoven fabric 8 is obtained. Further, as a specific shape of the spinneret 2, for example, one having the hole shape shown in Fig. 3 can be mentioned, and the spunbond nonwoven fabric manufacturing apparatus has a die having a large number of spinning holes (nozzles) having the hole shape shown in Fig. 3. When the nozzle hole shape shown in Fig. 3 is used, hollow fibers having a hollow cross-section as shown in Fig. 4 can be formed.

[0045] Further, as another specific shape of the spinneret 2, one having the hole shape as shown in Fig. 5 can be mentioned. When the nozzle hole shape shown in Fig. 5 is used, hollow fibers having a hollow cross-section as shown in Fig. 6 can be formed.

[0046] The melting temperature of the thermoplastic resin which is the raw material of the nonwoven fabric is not particularly limited. When the thermoplastic resin is a propylene-based polymer, it can preferably be set to a temperature of 180°C to 280°C, more preferably 190°C to 270°C, and still more preferably 200°C to 260°C.

[0047] The temperature of the cooling air is not particularly limited as long as it is the temperature at which the thermoplastic resin solidifies. When the thermoplastic resin is a propylene-based polymer, it is preferably 5°C to 50°C, more preferably 10°C to 40°C, and still more preferably 15°C to 30°C. Since the cooling air acts as a dispersion medium for sufficiently dispersing the fibers when it reaches the diffuser, from the viewpoint of ensuring uniformity, the air volume is usually 30 Nm 3 / min / m to 100 Nm 3 / min. Here, the temperature of the cooling air is preferably 20°C to 30°C. The air volume of the cooling air is preferably 60 Nm 3 / min.m or more, more preferably 75 Nm 3 / min.m or more, and even more preferably 90 Nm 3 / min.m or more. From the viewpoint of stable production, when the temperature of the cooling air is 20°C to 30°C, the upper limit value of the air volume may be 150 Nm 3 / min.m or less. The wind speed of the stretching air is usually 100 m / min to 10,000 m / min, preferably 500 m / min to 10,000 m / min.

[0048] As the spinning hole (nozzle), the outer diameter is 0.5 mm to 5.0 mm, the slit width is 0.05 mm to 0.5 mm, the number of slits is 2 to 10, preferably 3 to 6, and the canal width which is the interval between a plurality of slits is 0.04 mm to 0.15 mm, and the nozzle hole area is 0.1 mm 2 ~0.5 mm 2 It is preferable to use a die having a spinning hole. In order to obtain a non-woven fabric with high uniformity, the value obtained by dividing the canal width by the nozzle hole area (canal width / nozzle hole area) is preferably 0.35 mm -1 or more, more preferably 0.40 mm -1 or more.

[0049] In the present disclosure, the canal width in the above spinning hole is, for example, the width (interval) between the slits of a plurality of slits (nozzle holes) through which a thermoplastic resin shown in FIG. 3 or FIG. 5 is melt-extruded, and the nozzle hole area is the total area of all the slits (nozzle holes).

[0050] The non-woven fabric of the present disclosure is embossed. Therefore, the non-woven fabric of the present disclosure has a crimped portion and a non-crimped portion crimped by embossing. The degree of deformation A and the degree of deformation B of the non-woven fabric are calculated based on the single fiber cross-section of the fiber in the non-crimped portion which is a portion not embossed. The area ratio of the crimping part is preferably 5% to 20%, more preferably 6% to 19%. The area ratio of the crimping part is obtained by collecting a test piece with a size of 10 mm × 10 mm from the nonwoven fabric, observing the contact surface of the test piece with the embossing roll with an electron microscope (magnification: 100 times), and taking the ratio of the area of the thermally crimped part to the area of the observed nonwoven fabric. Also, the area ratio of the convex part formed on the embossing roll capable of forming the crimping part is also referred to as the "crimping area ratio".

[0051] When the nonwoven fabric of the present disclosure is a spunbond nonwoven fabric made of solid fibers, the spunbond nonwoven fabric can be manufactured by a conventional method.

[0052] The method for adjusting the degree of deformation ratio (degree of deformation A / degree of deformation B) of the nonwoven fabric to the range of 1.5 to 2.5 is not particularly limited, and from the viewpoint of productivity, it is preferable to perform calendering on the nonwoven fabric. The surface temperature of the main roll in the calendering process is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher, so as to deform the shape of the single fiber cross-section of one surface of the nonwoven fabric in contact with the calender roll, and it becomes possible to easily adjust the degree of deformation ratio (degree of deformation A / degree of deformation B) of the nonwoven fabric to the range of 1.5 to 2.5. The surface temperature of the main roll in the calendering process is preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower, so as to suppress the film formation of the nonwoven fabric due to excessive fusion of fibers and impart a preferable texture as a material for sanitary products and the like. The surface temperature of the main roll in the calendering process is preferably 50°C to 150°C. The linear pressure in the calendering process is preferably 0.3 MPa or higher, more preferably 0.4 MPa or higher, and even more preferably 0.5 MPa or higher, so as to deform the shape of the single fiber cross-section of one surface of the nonwoven fabric in contact with the calender roll, and it becomes possible to easily adjust the degree of deformation ratio (degree of deformation A / degree of deformation B) of the nonwoven fabric to the range of 1.5 to 2.5. The linear pressure in calendar processing is preferably 2.0 MPa or less, more preferably 1.5 MPa or less, and even more preferably 1.2 MPa or less, so that the voids inside the nonwoven fabric can be maintained and a preferable texture can be imparted as a material for sanitary products and the like. The linear pressure in calendar processing is preferably 0.3 MPa to 2.0 MPa. Examples of the material of the main roll used in calendar processing include metals such as steel. Examples of the material of the backup roll used in calendar processing include resins such as epoxy, special polyester, and aramid, and metals such as steel. The degree of irregularity ratio, degree of irregularity A, and degree of irregularity B can be within a predetermined range by adjusting the processing conditions of calendar processing. For example, by setting the temperature condition in calendar processing to a high temperature, the values of the degree of irregularity ratio, degree of irregularity A, and degree of irregularity B tend to increase. Also, by setting the pressure condition to a high pressure, the values of the degree of irregularity ratio, degree of irregularity A, and degree of irregularity B tend to increase.

[0053] <Nonwoven fabric laminate> (First nonwoven fabric laminate) The first nonwoven fabric laminate of the present disclosure includes a nonwoven fabric layer that is the nonwoven fabric of the present disclosure. As long as the first nonwoven fabric laminate includes a nonwoven fabric having a degree of irregularity ratio (degree of irregularity A / degree of irregularity B) of 1.5 to 2.5, it may have a structure in which two or more layers of the nonwoven fabric of the present disclosure are laminated, or at least one layer of the nonwoven fabric of the present disclosure and a knitted fabric, a woven fabric, a nonwoven fabric other than the nonwoven fabric of the present disclosure (for example, a nonwoven fabric having a degree of irregularity ratio (degree of irregularity A / degree of irregularity B) outside the range of 1.5 to 2.5), a film (including a sheet), etc. may be laminated in any order. Examples of the nonwoven fabric other than the nonwoven fabric of the present disclosure include various known short fiber nonwoven fabrics and long fiber nonwoven fabrics (for example, long fiber cellulose nonwoven fabrics) such as spunbond nonwoven fabric, meltblown nonwoven fabric, wet nonwoven fabric, spunlace nonwoven fabric, dry nonwoven fabric, dry pulp nonwoven fabric, airlaid nonwoven fabric, waterjet nonwoven fabric, flash spun nonwoven fabric, fibrillation nonwoven fabric, needle punched nonwoven fabric, etc.

[0054] The first nonwoven laminate preferably further includes a meltblown nonwoven layer together with the nonwoven layer which is the nonwoven of the present disclosure. The first nonwoven laminate may be configured to have nonwoven layers which are the nonwovens of the present disclosure on both sides of the meltblown nonwoven layer.

[0055] When manufacturing the first nonwoven laminate by laminating two or more layers of the nonwovens of the present disclosure, or when manufacturing the first nonwoven laminate by laminating at least one layer of the nonwovens of the present disclosure and materials other than the nonwovens in any order, the method of laminating (for example, bonding) each layer is not particularly limited. For example, various known methods can be adopted, including heat embossing, heat bonding methods such as ultrasonic welding, mechanical entanglement methods such as needle punching and water jet, methods using adhesives such as hot melt adhesives and urethane-based adhesives, and extrusion lamination.

[0056] (Second nonwoven laminate) The second nonwoven laminate of the present disclosure includes at least two nonwoven layers containing fibers of a thermoplastic resin, and is an embossed nonwoven laminate. The degree of irregularity (degree of irregularity A) defined by the following formula for the fibers at the unembossed portion on one surface of the nonwoven laminate, and the degree of irregularity (degree of irregularity B) defined by the following formula for the fibers at the unembossed portion on the other surface of the nonwoven laminate, the degree of irregularity ratio (degree of irregularity A / degree of irregularity B) is 1.5 to 2.5. Degree of irregularity = R / r (formula) In the above formula, R refers to the diameter of the circumscribed circle with respect to the cross-section orthogonal to the length direction of the single fiber of the fiber, and r refers to the diameter of the inscribed circle with respect to the cross-section orthogonal to the length direction of the single fiber of the fiber.

[0057] According to the second nonwoven fabric laminate of the present disclosure, suppression of bleeding of the adhesive component and texture are compatible. The reason is not clear, but similar to the case of the nonwoven fabric of the present disclosure, it is presumed that the surface of one side of the second nonwoven fabric laminate becomes a dense structure due to the presence of fibers with a flat single-fiber cross-section on one side of the second nonwoven fabric laminate, and bleeding of the adhesive component in the thickness direction of the second nonwoven fabric laminate is suppressed. On the other hand, it is presumed that the texture required for the nonwoven fabric laminate is ensured on the other side of the second nonwoven fabric laminate. The degree-of-irregularity ratio (degree of irregularity A / degree of irregularity B) for the second nonwoven fabric laminate is calculated in the same manner as for the nonwoven fabric of the present disclosure. The preferred range of the degree-of-irregularity ratio for the second nonwoven fabric laminate, and the preferred ranges of the degree of irregularity A for one side of the nonwoven fabric laminate and the degree of irregularity B for the other side of the nonwoven fabric laminate are the same as in the case of the nonwoven fabric of the present disclosure. Also, specific examples and preferred examples of the fibers of the thermoplastic resin used in the second nonwoven fabric laminate, the production method of the nonwoven fabric constituting the nonwoven fabric layer, the conditions of calendering, etc. are the same as in the case of the nonwoven fabric of the present disclosure.

[0058] The second nonwoven fabric laminate can be produced by laminating at least two layers of nonwoven fabric layers containing fibers of a thermoplastic resin and then performing the above-described calendering. The type of nonwoven fabric constituting the second nonwoven fabric laminate is not particularly limited, and examples include various known short-fiber nonwoven fabrics and long-fiber nonwoven fabrics (for example, long-fiber cellulose nonwoven fabrics) such as spunbond nonwoven fabric, meltblown nonwoven fabric, wet nonwoven fabric, spunlace nonwoven fabric, dry nonwoven fabric, dry pulp nonwoven fabric, airlaid nonwoven fabric, waterjet nonwoven fabric, flash-spun nonwoven fabric, fibrillated nonwoven fabric, needle-punched nonwoven fabric, etc. The second nonwoven fabric laminate is preferably a nonwoven fabric laminate in which two or more layers of one type of nonwoven fabric selected from the various nonwoven fabrics described above are laminated, or a nonwoven fabric laminate in which at least two types of nonwoven fabrics selected from the various nonwoven fabrics described above are each laminated in one or more layers. In the second nonwoven laminate, the fibers of the thermoplastic resin preferably contain polyolefin from the viewpoints of spinnability and drawability. The proportion of polyolefin in the thermoplastic resin contained in the fibers of the thermoplastic resin is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and particularly preferably 99% by mass or more. Further, the fibers of the thermoplastic resin contained in at least one layer of the nonwoven fabric layer may be hollow fibers.

[0059] As the second nonwoven laminate, it is preferable from the viewpoint of texture such as flexibility that the nonwoven fabric layer located on the surface on one side and the nonwoven fabric layer located on the surface on the other side are both spunbond nonwoven fabric layers. In this case, it is preferable from the viewpoints of preventing the adhesive component from bleeding through and quality (uniformity) that the second nonwoven laminate further includes a meltblown nonwoven fabric layer as an intermediate layer of the spunbond nonwoven fabric layer. For example, the second nonwoven laminate may have a two-layer structure of a spunbond nonwoven fabric layer / spunbond nonwoven fabric layer, or may have a three-layer structure of a spunbond nonwoven fabric layer / meltblown nonwoven fabric layer / spunbond nonwoven fabric layer. When the nonwoven fabric layer located on the surface on one side and the nonwoven fabric layer located on the surface on the other side are both spunbond nonwoven fabric layers, from the viewpoint of easily adjusting the degree of deformation ratio by calendar processing, the spunbond nonwoven fabric layer is preferably composed of hollow fibers.

[0060] The second nonwoven laminate is embossed. The area ratio of the crimped portion for the second nonwoven laminate is preferably 5% to 20%, and more preferably 6% to 19%. The area ratio of the crimped portion can be determined in the same manner as in the case of nonwoven fabric.

[0061] The basis weight of the second nonwoven laminate is preferably 20 g / m 2 or less from the viewpoint of flexibility, more preferably 17 g / m 2 or less, and still more preferably 15 g / m 2 or less. Further, the basis weight is preferably 5 g / m2 It is preferably the above, 7 g / m 2 More preferably, it is the above, 8 g / m 2 Even more preferably, it is the above. The basis weight of the second nonwoven laminate is 5 g / m 2 ~20 g / m 2 It is preferable that it is.

[0062] From the viewpoint of air permeability, the air permeability of the second nonwoven laminate is 30 cm 3 / cm 2 / sec or more is preferable, 50 cm 3 / cm 2 / sec or more is more preferable, 80 cm 3 / cm 2 / sec or more is even more preferable. From the viewpoint of bleeding through of the adhesive component, the air permeability of the second nonwoven laminate is 300 cm 3 / cm 2 / sec or less is preferable, 290 cm 3 / cm 2 / sec or less is more preferable, 280 cm 3 / cm 2 / sec or less is even more preferable. The air permeability of the second nonwoven laminate is 30 cm 3 / cm 2 / sec to 300 cm 3 / cm 2 / sec is preferable.

[0063] <Hygiene product> The hygiene product of the present disclosure has the nonwoven fabric of the present disclosure, the first nonwoven laminate of the present disclosure, or the second nonwoven laminate of the present disclosure. Examples of the hygiene product include absorbent articles such as paper diapers, sanitary napkins, and incontinence pads, medical hygiene materials such as bandages, medical gauze, and towels, and sanitary masks. The hygiene product of the present disclosure is not limited to these, and can also be suitably used for other hygiene product applications.

Examples

[0064] Hereinafter, embodiments of the present invention will be described in more detail based on examples. However, the present invention is not limited to these examples which are one embodiment of the present invention. Physical property values and the like in the examples and comparative examples were measured by the following methods.

[0065] (1) Degree of irregularity ratio The degree of irregularity ratio was calculated from the cross-sectional photographs of the nonwoven fabric or nonwoven fabric laminate observed with an SEM at a magnification of 600 times (SU3500 scanning electron microscope manufactured by Hitachi, Ltd.) according to the following method. In the unembossed portion of the single fiber constituting the nonwoven fabric or nonwoven fabric laminate, for the single fiber exposed on the surface of one side of the nonwoven fabric or nonwoven fabric laminate subjected to calendar processing, the diameter of the circumscribed circle (R A ) and the diameter of the inscribed circle (r A ) were obtained, and the degree of irregularity A (R A / r A ) was calculated from the obtained values. Also, in the unembossed portion of the single fiber constituting the nonwoven fabric or nonwoven fabric laminate, for the single fiber exposed on the surface on the side opposite to one side (that is, the other side) of the nonwoven fabric or nonwoven fabric laminate subjected to calendar processing, the diameter of the circumscribed circle (R B ) and the diameter of the inscribed circle (r B ) were obtained, and the degree of irregularity B (R B / r B ) was calculated from the obtained values. Arbitrarily select 10 single fibers from each surface of the nonwoven fabric or nonwoven fabric laminate, obtain the average value of the degree of irregularity A and the average value of the degree of irregularity B, and calculate the degree of irregularity ratio from the following formula. Degree of irregularity ratio = Average value of degree of irregularity (A) / Average value of degree of irregularity (B) Note that the nonwoven fabric laminate in this paragraph means the aforementioned first nonwoven fabric laminate and second nonwoven fabric laminate. In a nonwoven fabric laminate having a laminated structure with a nonwoven fabric, film, etc. other than the first nonwoven fabric laminate and the second nonwoven fabric laminate, the degree of irregularity ratio can be measured by separating the first nonwoven fabric laminate or the second nonwoven fabric laminate from its cross-sectional shape.

[0066] (2) Average fiber diameter The average fiber diameter was determined as follows. The nonwoven fabric or nonwoven fabric laminate to be measured was observed with an optical microscope (ECLIPSE E-400, manufactured by Nikon Corporation). One hundred fibers forming the nonwoven fabric on the screen were selected, and their fiber diameters were measured. The average value was taken as the average fiber diameter of the fibers.

[0067] (3) Basis weight Ten test pieces of 100 mm (flow direction: MD) × 100 mm (direction perpendicular to the flow direction: CD) were collected from the nonwoven fabric or nonwoven fabric laminate. The sampling locations of the test pieces were ten locations across the CD direction. Next, in an environment of 20°C and 50% RH relative humidity, the mass (g) of each collected test piece was measured using an upper-pan electronic balance (manufactured by Ken Seiko Kogyo Co., Ltd.). The average value of the masses of the test pieces was determined. The average value obtained was converted to the mass (g) per 1 m 2 and rounded to the first decimal place to obtain the basis weight (g / m 2 ) of each sample.

[0068] (4) Air permeability A test piece of 200 mm (MD) × 200 mm (CD) was collected from the nonwoven fabric or nonwoven fabric laminate, and the flow rate at a pressure difference of 125 Pa was measured using a Frazier air permeability measuring machine conforming to JIS L 1096 (2010).

[0069] (5) Hot melt (HM) shedding A coater gun unit (standard type) manufactured by Santool Co., Ltd. was mounted on the pass line of a winder device having a pay-off machine and a take-up machine, and a rotating drive roll with a diameter of 125 mm and a wrap angle of 90° was arranged 60 cm downstream from the back surface of the nonwoven fabric or nonwoven fabric laminate. In the above process, a nonwoven fabric or nonwoven fabric laminate with a width of 300 mm was guided from the pay-off machine to the take-up machine and run at a line speed of 100 m / min and a process tension of 50 N / m. Then, a hot melt adhesive (JM-8714ZP) manufactured by Sekisui Fuller Co., Ltd. was melted at 170°C in the coater gun and applied with a coating width of 50 mm and a coating amount of 5 g / m 2Coating was performed under the following conditions. After coating for 2 minutes, the weight of the hot melt adhesive that had penetrated through and been transferred onto the rotating drive roll was measured, and this value was taken as the hot melt penetration weight, and the determination was made according to the following criteria. A: 30 mg or less B: 31 mg or more and 60 mg or less C: 61 mg or more and 90 mg or less D: 91 mg or more and 120 mg or less E: 121 mg or more

[0070] (6) Texture Ten evaluators evaluated the texture of the nonwoven fabric or nonwoven fabric laminate. The evaluation results are shown according to the following criteria. A (Soft): When 10 - 8 out of 10 people felt that the touch was soft B (Normal): When 7 - 4 out of 10 people felt that the touch was soft E (Hard): When 3 - 1 out of 10 people felt that the touch was soft

[0071] (7) Comprehensive Judgment In the hot melt penetration and texture evaluation, those with all evaluations being "A" or "B" were given a comprehensive evaluation of "Pass", and if there was even one item of "C", "D", or "E", the comprehensive evaluation was "Fail".

[0072] [Example 1] Polypropylene (PP) resin with an MFR of 60 g / 10 min (measured at a temperature of 230°C and a load of 2160 g according to ASTM D - 1238) (melting point 161°C) was extruded by the spunbond method at a discharge rate of 0.81 g / min·Hole and a spinning temperature of 255°C through a nozzle with a diameter of φ0.4 mm, and the filament group was extruded toward the moving collection surface to prepare a solid - cross - section long - fiber nonwoven fabric (spinning speed 5000 m / min, average single - filament fineness 1.6 dtex). On top of it, polypropylene resin with an MFR of 300 g / 10 min was used, and by the melt - blown method, it was extruded at a discharge rate of 0.50 g / min·Hole, 190 kg / m / hour, and a spinning temperature of 270°C through a nozzle with a diameter of φ0.2 mm, and then spunbond was extruded on top of it under the same conditions as above. Next, the obtained nonwoven fabric laminate was passed between a flat roll and an embossing roll (pressure bonding area ratio 18.0%, pressure bonding temperature 130°C), and heat and pressure were adjusted by temperature and linear pressure to bond the fibers together, resulting in a nonwoven fabric laminate with a basis weight of 5 g / m 2 . Next, the obtained nonwoven fabric laminate was passed between calender rolls (main roll: mirror surface, surface temperature 90°C, sub roll: mirror surface, surface temperature 40°C, roll linear pressure 1.0 MPa, processing speed 20 m / min), and heat and pressure were adjusted by temperature and linear pressure to obtain a nonwoven fabric laminate. The properties of the obtained nonwoven fabric laminate were evaluated as described above. The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0073] [Example 2] A nonwoven fabric laminate was obtained and its properties were evaluated in the same manner as in Example 1, except that the basis weight was 15 g / m 2 . The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0074] [Example 3] A nonwoven fabric laminate was obtained and its properties were evaluated in the same manner as in Example 1, except that the basis weight was 20 g / m 2 . The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0075] [Example 4] Polypropylene (PP) resin (melting point 161°C) with an MFR of 60 g / 10 min (measured at a temperature of 230°C and a load of 2160 g according to ASTM D-1238) was extruded by the spunbond method at a discharge rate of 0.52 g / min·Hole and a spinning temperature of 240°C through a discharge hole having the shape shown in Figure 3 of -1 0.41 mm of canal width / nozzle hole area, and the filament group was extruded toward the moving collection surface to prepare a hollow cross-section long fiber nonwoven fabric (spinning speed 4365 m / min, average single fiber fineness 2.0 dtex). Next, the obtained nonwoven fabric was passed between a flat roll and an embossing roll (pressure bonding area ratio 18.0%, pressure bonding temperature 130°C), and heat and pressure were adjusted by temperature and linear pressure to bond the fibers together, resulting in a nonwoven fabric with a basis weight of 15 g / m 2 . Next, the same calendar processing as in Example 1 was performed to obtain a nonwoven fabric and its properties were evaluated. The properties of the obtained nonwoven fabric are shown in Table 1 below.

[0076] [Example 5] A nonwoven fabric was obtained and its properties were evaluated in the same manner as in Example 4, except that the basis weight was 20 g / m 2 . The properties of the obtained nonwoven fabric are shown in Table 1 below.

[0077] [Example 6] Polypropylene (PP) resin (melting point 161°C) with an MFR of 60 g / 10 min (measured at a temperature of 230°C and a load of 2160 g according to ASTM D-1238) was extruded by the spunbond method at a discharge rate of 0.42 g / min·Hole and a spinning temperature of 240°C through a discharge hole having a shape as shown in FIG. 3 with a canal width / nozzle hole area = 0.41 mm -1 , and the filament group was extruded toward the moving collection surface to prepare a hollow cross-section long fiber nonwoven fabric (spinning speed 4365 m / min, average single fiber fineness 1.6 dtex). On top of that, polypropylene resin with an MFR of 300 g / 10 min was used, and by the meltblown method, it was extruded at a discharge rate of 0.50 g / min·Hole, 190 kg / m / hour, and a spinning temperature of 270°C through a nozzle diameter of φ0.2 mm, and then spunbond was extruded on top of it under the same conditions as above. Next, the obtained nonwoven fabric laminate was passed between a flat roll and an embossing roll (pressure bonding area ratio 18.0%, pressure bonding temperature 130°C), and the heat and pressure were adjusted by temperature and linear pressure to bond the fibers together to obtain a nonwoven fabric laminate with a basis weight of 5 g / m 2 . Next, the obtained nonwoven fabric laminate was passed between calendar rolls (main roll: mirror surface, surface temperature 90°C, sub roll: mirror surface, surface temperature 40°C, roll linear pressure 1.0 MPa, processing speed 20 m / min), and the heat and pressure were adjusted by temperature and linear pressure to obtain a nonwoven fabric laminate. The properties of the obtained nonwoven fabric laminate were evaluated as described above. The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0078] [Example 7] The basis weight was 15 g / m 2and a nonwoven fabric laminate was obtained in the same manner as in Example 6 except that the conditions of calendar processing were changed (main roll: mirror finish, surface temperature 50°C, sub roll: mirror finish, surface temperature 40°C, roll linear pressure 0.5 MPa, processing speed 20 m / min). The properties of the obtained nonwoven fabric laminate were evaluated. The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0079] [Example 8] With a basis weight of 20 g / m 2 A nonwoven fabric laminate was obtained in the same manner as in Example 7 except for this, and its properties were evaluated. The properties of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0080] [Comparative Example 1] A nonwoven fabric laminate was obtained in the same manner as in Example 1 except that calendar processing was not performed, and its properties were evaluated. The properties of the obtained nonwoven fabric are shown in Table 1 below.

[0081] [Comparative Example 2] Polypropylene (PP) resin (melting point 161°C) with an MFR of 60 g / 10 min (measured at a temperature of 230°C and a load of 2160 g according to ASTM D-1238) was extruded by the spunbond method at a discharge rate of 1.01 g / min·Hole and a spinning temperature of 255°C through a nozzle with a diameter of φ0.4 mm, and the filament group was extruded toward the moving collection surface to prepare a solid cross-section long fiber nonwoven fabric (spinning speed 5000 m / min, average single fiber fineness 2.0 dtex). Next, the obtained nonwoven fabric was passed between a flat roll and an embossing roll (pressure bonding area ratio 18.0%, pressure bonding temperature 130°C), and heat and pressure were adjusted by temperature and linear pressure to bond the fibers to obtain a nonwoven fabric with a basis weight of 15 g / m 2 and its properties were evaluated. The properties of the obtained nonwoven fabric are shown in Table 1 below.

[0082] [Comparative Example 3] With a basis weight of 20 g / m 2 A nonwoven fabric was obtained in the same manner as in Comparative Example 2 except for this, and its properties were evaluated. The properties of the obtained nonwoven fabric are shown in Table 1 below.

[0083] [Comparative Example 4] A nonwoven laminate was obtained and its properties were evaluated in the same manner as in Example 2, except that the conditions for calendar processing were changed (main roll: mirror finish, surface temperature 50°C, sub roll: mirror finish, surface temperature 40°C, roll linear pressure 0.5 MPa, processing speed 20 m / min). The properties of the obtained nonwoven laminate are shown in Table 1 below.

[0084] [Comparative Example 5] A nonwoven laminate was obtained and its properties were evaluated in the same manner as in Example 2, except that the conditions for calendar processing were changed (main roll: mirror finish, surface temperature 100°C, sub roll: mirror finish, surface temperature 40°C, roll linear pressure 1.5 MPa, processing speed 20 m / min). The properties of the obtained nonwoven laminate are shown in Table 1 below.

[0085] [Comparative Example 6] A nonwoven laminate was obtained and its properties were evaluated in the same manner as in Example 6, except that calendar processing was not performed. The properties of the obtained nonwoven laminate are shown in Table 1 below.

[0086] [Comparative Example 7] Polypropylene (PP) resin (melting point 161°C) with an MFR of 30 g / 10 min (measured at a temperature of 230°C and a load of 2160 g according to ASTM D-1238) was spun by the spunbond method at a discharge rate of 0.52 g / min·Hole and a spinning temperature of 245°C, and discharged from a discharge hole having a shape as shown in FIG. 3 of 0.41 mm -1 of the canal width / nozzle hole area, and the filament group was extruded toward the moving collection surface to prepare a hollow cross-section long fiber nonwoven fabric (spinning speed 4365 m / min, average single fiber fineness 1.6 dtex). On top of that, polypropylene resin with an MFR of 300 g / 10 min was used, and by the meltblown method, at a discharge rate of 0.50 g / min·Hole, 190 kg / m / hour, and a spinning temperature of 270°C, it was discharged from a nozzle diameter of φ0.2 mm, and then spunbond was extruded on top of it under the same conditions as above. Next, the obtained nonwoven laminate was passed between a flat roll and an embossing roll (pressure bonding area ratio 18.0%, pressure bonding temperature 130°C), and heat and pressure were adjusted by temperature and linear pressure to bond the fibers together to obtain a nonwoven laminate with a basis weight of 20 g / m 2 . Next, the obtained nonwoven fabric laminate was passed between calender rolls (main roll: mirror surface, surface temperature 90°C, sub-roll: mirror surface, surface temperature 40°C, roll linear pressure 1.0 MPa, processing speed 20 m / min) to adjust the heat and pressure with temperature and linear pressure to obtain a nonwoven fabric laminate. The characteristics of the obtained nonwoven fabric laminate were evaluated as described above. The characteristics of the obtained nonwoven fabric laminate are shown in Table 1 below.

[0087]

Table 1

[0088] In Table 1, S in "layer structure" means a spunbond nonwoven fabric, and SMS means a nonwoven fabric laminate having a three-layer structure of a spunbond nonwoven fabric layer / meltblown nonwoven fabric layer / spunbond nonwoven fabric layer. In Table 1, "solid" in "cross-sectional shape" means that the fibers contained in the spunbond nonwoven fabric are solid fibers, and "hollow" means that the fibers contained in the spunbond nonwoven fabric are hollow fibers. As is clear from the evaluation results in Table 1, the nonwoven fabric or nonwoven fabric laminate of the example in which the degree of irregularity ratio is in the range of 1.5 to 2.5 is compared with the nonwoven fabric or nonwoven fabric laminate of the comparative example in which the degree of irregularity ratio is less than 1.5, and it can be seen that the penetration of the hot melt adhesive as an adhesive component is suppressed and the texture is excellent.

Explanation of symbols

[0089] 1 ··· Extruder 2 ··· Spinning die 3 ··· Hollow fiber 4 ··· Cooling air 5 ··· Diffuser 6 ··· Catching device 7 ··· Suction device 8 ··· Spunbond nonwoven fabric

Claims

1. A nonwoven fabric containing fibers of a thermoplastic resin and having an embossed pattern, wherein the degree of irregularity (degree of irregularity A) defined by the following formula for the fibers at the unembossed portion on one surface of the nonwoven fabric and the degree of irregularity (degree of irregularity B) defined by the following formula for the fibers at the unembossed portion on the other surface of the nonwoven fabric satisfy a degree of irregularity ratio (degree of irregularity A / degree of irregularity B) of 1.5 to 2.

5. Degree of irregularity = R / r (formula) (In the above formula, R represents the diameter of the circumscribed circle with respect to the cross section orthogonal to the longitudinal direction of the single fiber of the fiber, and r represents the diameter of the inscribed circle with respect to the cross section orthogonal to the longitudinal direction of the single fiber of the fiber.)

2. The nonwoven fabric according to claim 1, wherein the fibers of the thermoplastic resin contain polyolefin.

3. The nonwoven fabric according to claim 1, wherein the fibers of the thermoplastic resin are hollow fibers.

4. The basis weight is 5 g / m ２ to 20 g / m ２ The nonwoven fabric according to claim 1, wherein the basis weight is 5 g / m

5. The air permeability is 30 cm ３ / cm ２ / sec to 300 cm ３ / cm ２ / sec, and the nonwoven fabric according to claim 1

6. A nonwoven fabric laminate comprising a nonwoven fabric layer which is the nonwoven fabric according to claim 1.

7. A nonwoven fabric laminate comprising at least two nonwoven fabric layers containing fibers of a thermoplastic resin and having an embossed pattern, wherein the degree of irregularity (degree of irregularity A) defined by the following formula for the fibers at the unembossed portion on one surface of the nonwoven fabric laminate and the degree of irregularity (degree of irregularity B) defined by the following formula for the fibers at the unembossed portion on the other surface of the nonwoven fabric laminate satisfy a degree of irregularity ratio (degree of irregularity A / degree of irregularity B) of 1.5 to 2.

5. Degree of irregularity = R / r (formula) (In the above formula, R represents the diameter of the circumscribed circle with respect to the cross section orthogonal to the longitudinal direction of the single fiber of the fiber, and r represents the diameter of the inscribed circle with respect to the cross section orthogonal to the longitudinal direction of the single fiber of the fiber.)

8. The nonwoven fabric laminate according to claim 7, wherein the fibers of the thermoplastic resin contain polyolefin.

9. The nonwoven fabric laminate according to claim 7, wherein the fibers of the thermoplastic resin contained in at least one of the nonwoven fabric layers are hollow fibers.

10. The basis weight is 5 g / m ２ to 20 g / m ２ The nonwoven fabric laminate according to claim 7, wherein the basis weight is 5 g / m

11. The air permeability is 30 cm ３ / cm ２ / sec to 300 cm ３ / cm ２ / sec, and the nonwoven fabric laminate according to claim 7.

12. The nonwoven fabric laminate according to claim 7, wherein the nonwoven fabric layer located on the surface on one side of the nonwoven fabric laminate and the nonwoven fabric layer located on the surface on the other side thereof are both spunbond nonwoven fabric layers.

13. The nonwoven fabric laminate according to claim 12, further comprising a meltblown nonwoven fabric layer as an intermediate layer.

14. A sanitary product having the nonwoven fabric according to claim 1 or the nonwoven fabric laminate according to claim 6 or claim 7.

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