TWI550155B - Not weaving - Google Patents

Description

Non-woven

The present invention relates to a nonwoven fabric.

The applicant of the present application has proposed a technique for producing a non-woven fabric by first disposing a web comprising low-stretched inelastic fibers on one side of a web comprising elastic fibers, and performing hot air-type hot air treatment on the webs. The fibers are thermally fused to each other, and the fiber sheets in which the webs are integrated are stretched to stretch the low-stretch non-elastic fibers, and then the fiber sheets are released to form a nonwoven fabric (Patent Document) 1). In the method for producing a nonwoven fabric described in Patent Document 1, when the fiber sheet is stretched, an extension device having a pair of uneven rollers that can mesh with each other is used. The technique of extending using such an extension device including a pair of embossing rolls is described in Patent Document 1, and is also described in, for example, Patent Documents 2, 4, and 5.

As another technique different from this technique, Patent Document 3 discloses a technique for imparting a water-permeable nonwoven fabric having a water-permeable imparting agent for a fibrous product.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-7924

Patent Document 2: Japanese Patent Laid-Open Publication No. 2013-189745

Patent Document 3: Japanese Patent Laid-Open Publication No. 2000-178876

Patent Document 4: Japanese Patent Laid-Open Publication No. 2010-119861

Patent Document 5: Japanese Patent Laid-Open Publication No. 2012-67426

The nonwoven fabric produced by the manufacturing method described in Patent Document 1 is formed to include an elastic fiber and an inelastic fiber having a non-uniform thickness in the longitudinal direction. If the thickness of the inelastic fibers is not uniform, the skin feels good. However, there is no description about the dryness of the fingertips which increase the residual liquid residue on the surface.

Further, in Patent Document 2, it is necessary to use a stretchable fiber, that is, an elastic fiber. Further, Patent Document 2 discloses that the fiber diameter of the fiber is reduced by the stretching device, but there is no description about the dryness of the finger which is less to increase the liquid residue on the surface.

Further, since the water-permeable non-woven fabric described in Patent Document 3 is provided with the water-permeable imparting agent, the liquid residue on the surface is small, and the dryness of the touch is improved. However, in Patent Document 3, there is no case where the constituent fibers are extended to form a portion having a relatively small fiber diameter and a portion having a relatively large fiber diameter, and a hydrophilic material is changed by extending the fiber to which the oil agent is adhered. Any ideas.

The nonwoven fabric produced by the manufacturing method described in Patent Document 1 is formed to include an elastic fiber and an inelastic fiber having a non-uniform thickness in the longitudinal direction. If the thickness of the inelastic fibers is not uniform, the skin feels good. However, the industry has a desire to make the skin feel better.

Further, in Patent Document 2, it is necessary to use a stretchable fiber, that is, an elastic fiber. Further, Patent Document 2 discloses that the fiber diameter of the fiber is reduced by the stretching device. However, the fiber diameter is relatively small in the portion where the fiber diameter is relatively small and the fiber diameter is thick in one fiber. There is no record of where the boundary between the part and the thicker part is placed.

Further, in Patent Document 4, there is no description about the use of high-stretch fibers. Further, in Patent Document 4, the fiber diameter of the fiber is reduced by the stretching device, and there is no description about the portion where the fiber diameter is thinner and the fiber diameter is thicker in one fiber. Any ideas.

Further, in Patent Document 5, there is no description about the use of high-stretch fibers. Further, in Patent Document 5, the core sheath is peeled off by the stretching device to reduce the fiber diameter. However, the position where the fiber diameter portion and the thick portion should be disposed at the boundary is not present. Any record.

Accordingly, it is an object of the present invention to provide a non-woven fabric which can eliminate the disadvantages of the prior art described above.

The present invention (first invention) relates to a nonwoven fabric comprising a plurality of fusion portions formed by thermally fusing the intersections of constituent fibers. The constituent fiber includes a high-stretch fiber, and the constituent fiber has a fiber diameter which is sandwiched between two adjacent small-diameter portions having a small fiber diameter between the adjacent fusion portions. Large diameter department. The hydrophilicity of the small diameter portion is lower than the hydrophilicity of the large diameter portion.

The present invention (second invention) relates to a nonwoven fabric comprising a plurality of fusion portions formed by thermally fusing the intersections of constituent fibers. The above constituent fibers include high elongation fibers. In view of the above-mentioned constituent fibers, the constituent fibers have a large diameter portion having a large fiber diameter sandwiched by two small-diameter portions having a small fiber diameter between the adjacent fusion portions. The point of change from the small-diameter portion adjacent to the fusion portion to the large-diameter portion is within a range of 1/3 of the distance from the fusion portion to the adjacent portion of the fusion portion.

1a‧‧‧Fiber sheets

1A‧‧‧Nonwoven

1B‧‧‧Nonwoven

10‧‧‧Fiber

11‧‧‧constituting fibers

12‧‧‧Fuse Department

13‧‧‧Rocks

13a‧‧‧Top area

13b‧‧‧Bottom area

13c‧‧‧Side area

14‧‧‧ recessed section

16‧‧‧Little Trails Department

17‧‧‧The Great Trails Department

18‧‧‧Change point

100‧‧‧ manufacturing equipment

100A

100B‧‧‧ manufacturing equipment

200‧‧‧Fiber web formation

201‧‧‧Fiber web forming device

300‧‧‧Hot Air Treatment Department

301‧‧‧ filter cover

302‧‧‧ conveyor belt

400‧‧‧Extension

401‧‧‧ bump roll

402‧‧‧ bump roll

403‧‧‧ Large diameter convex

404‧‧‧ Large diameter convex

A‧‧‧ non-woven front

b‧‧‧The back of the non-woven fabric

AT‧‧‧A region on the side of the fusion joint

BT‧‧‧ another fusion zone side area

CT‧‧‧Central Area

T‧‧‧injection

T‧‧‧ interval

W‧‧‧ interval

X‧‧‧ direction

Y‧‧‧ direction

Z‧‧‧ Thickness direction

Fig. 1 is a perspective view showing an embodiment of a nonwoven fabric of the present invention (first invention).

Fig. 2 is a schematic view showing a cross section of the non-woven fabric shown in Fig. 1 in the thickness direction.

Fig. 3 is a view for explaining a state in which the constituent fibers constituting the nonwoven fabric shown in Fig. 1 are fixed to each other by the heat fusion portion.

Fig. 4 is a schematic view showing a manufacturing apparatus which can be preferably used for manufacturing the nonwoven fabric shown in Fig. 1.

Fig. 5 is a schematic view showing an extending portion of the manufacturing apparatus shown in Fig. 4;

Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5.

7(a) to 7(c) are explanatory views for explaining a state in which a plurality of small-diameter portions and large-diameter portions are formed in one constituent fiber between adjacent fusion portions.

Fig. 8 is a perspective view showing an embodiment of the nonwoven fabric of the second aspect of the invention.

Fig. 9 is a schematic view showing a cross section in the thickness direction of the nonwoven fabric shown in Fig. 8.

Fig. 10 is a view for explaining a state in which the constituent fibers constituting the nonwoven fabric shown in Fig. 8 are fixed to each other by the heat fusion portion.

Fig. 11 is a schematic view showing a manufacturing apparatus which can be preferably used for manufacturing the nonwoven fabric shown in Fig. 8.

Fig. 12 is a schematic view showing an extending portion of the manufacturing apparatus shown in Fig. 11;

Figure 13 is a cross-sectional view taken along line VI-VI of Figure 12;

(a) to (c) of FIG. 14 are explanatory views for explaining a state in which a plurality of small-diameter portions and large-diameter portions are formed in one constituent fiber between adjacent fusion portions.

Hereinafter, the present invention (first invention) will be described based on preferred embodiments thereof with reference to the drawings.

Fig. 1 is a perspective view showing a nonwoven fabric 1A (hereinafter also referred to as "nonwoven fabric 1A") according to an embodiment of the present invention (first invention). Fig. 2 is a schematic view showing a cross section of the nonwoven fabric 1A shown in Fig. 1 in the thickness direction. Fig. 3 is an enlarged schematic view showing the constituent fibers 11 of the nonwoven fabric 1A shown in Fig. 1. As shown in FIG. 3, the nonwoven fabric 1A is a nonwoven fabric having a plurality of fusion portions 12 formed by thermally fusing the intersections of the constituent fibers 11 to each other. Here, the intersection of the constituent fibers 11 also constitutes a joint point between the constituent fibers 11. This joint is formed by thermally fusing the constituent fibers 11 to each other. That is, the joint is the fusion portion 12. In the present embodiment, as shown in FIG. 1, the nonwoven fabric 1A is a non-woven fabric having a concavo-convex structure in which stripe-shaped ridge portions 13 and recessed portions 14 extending in one direction (X direction) are alternately arranged. Specifically, as shown in FIG. 2, the nonwoven fabric 1A has a plurality of ridge portions 13 in which the cross-sectional shapes of the front and back surfaces a and b are convexly formed above the thickness direction (Z direction), and the adjacent ridges are located. The recesses between the parts 13, 13 Part 14. The cross-sectional shape of both the front and back sides a and b of the concave strip portion 14 is formed in a concave shape above the thickness direction (Z direction) of the nonwoven fabric. In other words, the cross-sectional shapes of the front and back surfaces a and b of the concave strip portion 14 are both convex toward the lower side in the thickness direction (Z direction) of the nonwoven fabric. Further, the plurality of ridge portions 13 are continuously extended in one direction (X direction) of the nonwoven fabric 1A, and the plurality of concave strip portions 14 are also formed in a groove shape continuously extending in one direction X of the nonwoven fabric 1A. The ridge portion 13 and the groove portion 14 are parallel to each other and alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

Further, when the non-woven fabric 1A is viewed in cross section as shown in Fig. 2, the nonwoven fabric 1A has a top portion 13a, a bottom portion 13b, and a side portion 13c located between the portions 13a, 13b. Also, the top of the ridge portion 13 is formed by the top portion 13a, and the bottom portion of the concave portion 14 is formed by the bottom portion 13b. The top portion 13a, the bottom portion 13b, and the side portion 13c continuously extend in one direction (X direction) of the nonwoven fabric 1A. When the non-woven fabric 1A is observed in a cross section as shown in FIG. 2 in the top region 13a, the bottom region 13b, and the side portion 13c, the thickness 3 of the non-woven fabric 1A in the Z direction is equally divided, and the upper portion in the thickness direction (Z direction) is set as the top portion. In the region 13a, the center portion in the thickness direction (Z direction) is defined as the side portion 13c, and the portion below the thickness direction (Z direction) is defined as the bottom portion 13b. The above distinction was made by the following method.

[Method of Distinguishing Top Area 13a, Bottom Area 13b, and Side Area 13c]

The non-woven fabric 1A was cut in the Y direction using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and a scanning electron microscope (JCM-5100 (trade name) manufactured by JEOL Ltd.) was used. The cut non-woven fabric 1A is enlarged until the portion to be measured sufficiently enters the field of view to be measured (10 to 100 times), and the thickness of the non-woven fabric 1A in the Z direction is equally divided into three, and the upper portion in the thickness direction (Z direction) is set. In the top region 13a, the center portion in the thickness direction (Z direction) is defined as the side portion 13c, and the portion below the thickness direction (Z direction) is defined as the bottom portion 13b.

In the case of a diaper or the like which is commercially available, the diaper or the like is sprayed with a cold spray to be cooled, and the adhesion is lowered. Then carefully and carefully strip the materials The material was obtained as a non-woven fabric, and the cutting and measurement were carried out as described above.

The nonwoven fabric 1A is manufactured by performing uneven processing on the fiber sheet 1a with respect to the uneven rollers 401 and 402 as one of the following. One direction (X direction) of the non-woven fabric 1A is the same direction as the machine direction (MD (Machine Direction), the traveling direction) when the nonwoven fabric 1A is formed by the uneven processing of the fiber sheet 1a, and one direction of the nonwoven fabric 1A. The direction (the Y direction) orthogonal to the (X direction) is the same direction as the orthogonal direction (CD (Cross Direction), the roller axis direction) orthogonal to the above-described machine direction (MD, traveling direction).

The constituent fibers 11 of the nonwoven fabric 1A contain high-stretch fibers. Here, the high-stretch fiber included in the constituent fiber 11 means a fiber having a high elongation at the fiber stage of the raw material and a high elongation at the stage of the nonwoven fabric 1A to be produced. The "high-stretch fiber" is a low-speed fiber, for example, as described in paragraph [0033] of JP-A-2010-168715, in addition to the elastic fiber (elastic body). After melt-spinning to obtain a composite fiber, heat treatment and/or crimping treatment without stretching treatment, thereby obtaining a heat-extensible fiber in which the crystal state of the resin is changed by heating to extend the length; or a fiber produced by using a resin such as polypropylene or polyethylene and having a spinning speed set to a relatively low condition; or dry-blending polyethylene into a polyethylene-polypropylene copolymer having a low crystallinity or polypropylene A fiber or the like produced by spinning. Among these fibers, the high-stretch fibers are preferably core-sheath type composite fibers having heat fusion properties. The core-sheath type composite fiber may be a concentric core sheath type, may be an eccentric core sheath type, may be a side-by-side type or a profiled type, and is preferably a concentric core sheath type. The fineness of the high-stretch fiber is preferably 1.0 dtex or more, more preferably 2.0 dtex or more, in terms of a raw material stage, from the viewpoint of producing a good non-woven fabric such as softness and skin feel, and the like. It is preferably 10.0 dtex or less, more preferably 8.0 dtex or less, and specifically preferably 1.0 dtex or more and 10.0 dtex or less, more preferably 2.0 dtex or more and 8.0 dtex or less. In the present specification, the skin touch refers to a property obtained by performing a sensory evaluation on the feeling when the skin is in contact with the liquid. In addition, the following finger dryness refers to the inclusion of residual liquid. The characteristics obtained by sensory evaluation when the skin is in contact with the state. Therefore, the dryness of the touch is different from the feel of the skin.

The constituent fibers 11 of the nonwoven fabric 1A may be composed of other fibers in addition to the high-stretch fibers, and are preferably composed of only non-elastic fibers, and a large amount of fibers having a small diameter and a low degree of hydrophilicity are present in the vicinity of the fusion point. Preferably, all of the fusion points are formed of high-stretch fibers, and thus it is further preferred to consist only of high-stretch fibers. Examples of the other fiber include a non-heat-extensible core-sheath type heat-fusible composite fiber including two kinds of components having different melting points and a heat-fusible fiber (for example, cotton or pulp). Natural fiber, enamel or acetate fiber, etc.). In the case where the non-woven fabric 1A0 is composed of other fibers in addition to the high-stretch fibers, the ratio of the high-stretch fibers in the nonwoven fabric 1A0 is preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably It is 100% by mass.

The heat-expandable fiber as an example of the high-stretch fiber is a composite fiber which is not subjected to elongation treatment or weak elongation treatment at the raw material stage, and has, for example, a first resin component constituting the core portion and a polyethylene resin constituting the sheath portion. In the second resin component, the first resin component has a higher melting point than the second resin component. The first resin component is a component that exhibits thermal elongation of the fiber, and the second resin component is a component that exhibits heat fusion properties. The melting point of the first resin component and the second resin component was measured by using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Co., Ltd.), and the fiber sample (sample weight: 2 mg) which was finely cut at a temperature increase rate of 10 ° C / Min was subjected to thermal analysis to determine the melting peak temperature of each resin and defined as its melting peak temperature. When the melting point of the second resin component cannot be clearly measured by the method, the resin is defined as "a resin having no melting point". In this case, the temperature at which the molecules of the second resin component start to flow is a temperature at which the second resin component is fused to the extent that the fusion point strength of the fiber can be measured, and the softening point is used instead of the melting point.

The second resin component constituting the sheath portion contains a polyethylene resin as described above. Examples of the polyethylene resin include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). More preferably, it is a high density polyethylene having a density of 0.935 g/cm ³ or more and 0.965 g/cm ³ or less. The second resin component constituting the sheath portion is preferably a polyethylene resin alone, but may be blended with other resins. Examples of the other resin to be blended include a polypropylene resin, an ethylene-vinyl acetate copolymer (EVA), and an ethylene-vinyl alcohol copolymer (EVOH). However, the second resin component constituting the sheath portion is preferably a polyethylene resin in an amount of 50% by mass or more, particularly preferably 70% by mass or more and 100% by mass or less based on the resin component of the sheath portion. Further, the polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, more preferably 11.5 nm or more and 18 nm or less.

As the first resin component constituting the core portion, a resin component having a higher melting point than the polyethylene resin as the constituent resin of the sheath portion can be used without particular limitation. Examples of the resin component constituting the core portion include polyolefin resins (excluding polyethylene resins) such as polypropylene (PP), polyethylene terephthalate (PET), and polybutylene terephthalate (for example). Polyester resin such as PBT). Further, a polyamine polymer or a resin component may be used as a copolymer of two or more kinds. A plurality of resins may be blended and used, and in this case, the melting point of the core is set to the melting point of the resin having the highest melting point. In terms of the ease of producing the nonwoven fabric, it is preferable that the difference between the melting point of the first resin component constituting the core portion and the melting point of the second resin component constituting the sheath portion (the former - the latter) is 20 ° C or higher, and more preferably Below 150 °C.

The preferred orientation index of the first resin component in the thermally extensible fiber as an example of the high-stretch fiber is naturally different depending on the resin to be used, for example, when the first resin component is a polypropylene resin, the alignment The index is preferably 60% or less, more preferably 40% or less, and still more preferably 25% or less. When the first resin component is a polyester, the orientation index is preferably 25% or less, more preferably 20% or less, still more preferably 10% or less. On the other hand, the second resin component preferably has an alignment index of 5% or more, more preferably 15% or more, still more preferably 30% or more. The alignment index is an index of the degree of alignment of the polymer chains constituting the resin of the fiber.

The orientation index of the first resin component and the second resin component can be obtained by Japanese Patent Laid-Open The method described in paragraphs [0027] to [0029] of Japanese Patent Publication No. 2010-168715 is obtained. Further, a method of achieving the above-described alignment index for each of the resin components in the thermally extensible fiber is described in paragraphs [0033] to [0036] of JP-A-2010-168715.

Further, the elongation of the high-stretch fiber is 100% or more, preferably 200% or more, more preferably 250% or more, and preferably 800% or less, more preferably 500% or less, more preferably 500% or less. 400% or less, specifically, it is preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, further preferably 250% or more and 400% or less. By using a high-stretch fiber having an elongation of the range, the fiber is smoothly stretched in the stretching device, and the following point 18 from the small-diameter portion 16 to the large-diameter portion 17 is adjacent to the fusion portion 12 The skin feels good. Further, the elongation of the high-stretch fiber is 60% or more, preferably 70% or more, more preferably 80% or more, and more preferably 200% or less, still more preferably 150% or less, and more preferably in the non-woven stage. 120% or less, specifically, it is preferably 60% or more and 200% or less, more preferably 70% or more and 170% or less, and still more preferably 80% or more and 150% or less. It is particularly preferable that the elongation of the non-woven fabric produced by the ratio of the high-stretch fibers is 100%.

The elongation of the high-stretch fiber is determined according to JIS L-1015 under the conditions of measuring the ambient temperature and humidity of 20±2°C, 65±2% RH, the clamping interval of the tensile testing machine of 20 mm, and the stretching speed of 20 mm/min. The measurement is used as a reference. Further, when the self-manufactured non-woven fabric is used to collect the fibers and the elongation is measured, and the nip interval cannot be set to 20 mm, that is, when the fiber length to be measured is less than 20 mm, the nip interval is set to 10 mm or The measurement was carried out at 5 mm.

The ratio of the first resin component to the second resin component in the high-stretch fiber (mass ratio, the former: the latter) is preferably 10:90 to 90:10, particularly 20:80 to 80:20 at the raw material stage, and further It is 50:50~70:30. The fiber length of the high-stretch fiber can be used according to the manufacturing method of the nonwoven fabric. When the nonwoven fabric is produced by the carding method as described below, for example, the fiber length is preferably about 30 to 70 mm.

The fiber diameter of the high-stretch fiber can be appropriately selected depending on the specific use of the nonwoven fabric in the raw material stage. When a non-woven fabric is used as a constituent member of an absorbent article such as a front sheet of an absorbent article, it is preferably used in an amount of 10 μm or more, particularly preferably 15 μm or more, and preferably 35 μm or less, particularly preferably When 30 μm or less is used, specifically, it is preferably 10 μm or more and 35 μm or less, particularly 15 μm or more and 30 μm or less. The above fiber diameter was measured by the following method.

[Determination of fiber diameter of fibers]

As the fiber diameter of the fiber, the fiber diameter (μm) was measured by observing the cross section of the fiber by 200 to 800 times using a scanning electron microscope (JCM-5100, manufactured by JEOL Ltd.). The cross section of the fiber was obtained by cutting a fiber using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). The fiber diameter at the time of five approximate circular shapes was measured for the extracted one fiber, and the average value of the five values measured separately was set as the diameter of the fiber.

In the case of using the heat-extensible fiber as an example of the high-stretch fiber in the raw material stage, in addition to the above-mentioned heat-extensible fiber, Japanese Patent No. 4131852, Japanese Patent Laid-Open Publication No. 2005-350836, and Japanese Patent No. The fibers described in JP-A-2007-303035, JP-A-2007-204899, JP-A-2007-204901, and JP-A-2007-204902.

As shown in Fig. 3, the non-woven fabric of the present invention (first invention) has one of the constituent fibers 11 of the non-woven fabric 1A, and the constituent fibers 11 have the adjacent fusion portions 12 and 12 therebetween. The large diameter portion 17 having a large fiber diameter sandwiched by the small diameter portions 16 and 16 having two small fiber diameters. Specifically, as shown in FIG. 3, one of the constituent fibers 11 of the nonwoven fabric 1A is formed, and the small-diameter portion 16 having a small fiber diameter is self-contained with another constituent fiber with substantially the same fiber diameter. The fusion portion 12 formed by heat fusion at the intersection of 11 is formed to be extended. Further, attention is paid to the one constituent fiber 11 which is formed between the small diameter portions 16 and 16 which are extended from the adjacent fusion portions 12 and 12, and has a fiber diameter larger than the small diameter portion 16 The large diameter portion 17 is formed by extending substantially the same fiber diameter. As described in detail, the nonwoven fabric 1A has the constituent fibers 11 which are focused on one constituent fiber 11 and have a fusion portion 12 disposed one by one from the adjacent fusion portions 12 and 12 to the other fusion portion 12 The small diameter portion 16 on the side, the one large diameter portion 17, and the small diameter portion 16 on the other fusion portion 12 side. In the non-woven fabric 1A, as shown in Fig. 3, one of the constituent fibers 11 of the nonwoven fabric 1A is formed, and a plurality of the adjacent constituent portions 12 and 12 are provided between the two nonwoven fabrics 1 and 12 (not in the nonwoven fabric 1A). The constituent fibers 11 of the large diameter portion 17 are formed. As described in detail, the nonwoven fabric 1A has the constituent fibers 11 which are focused on one constituent fiber 11 and have a fusion portion 12 disposed one by one from the adjacent fusion portions 12 and 12 to the other fusion portion 12 The small diameter portion 16 on the side, the first large diameter portion 17, the small diameter portion 16, the second large diameter portion 17, and the small diameter portion 16 on the other fusion portion 12 side. By having the small-diameter portion 16 having low rigidity adjacent to the fusion portion 12 for increasing the rigidity of the nonwoven fabric 1A as described above, the softness of the nonwoven fabric 1A is improved, and the skin feel is good. In addition, the smaller the large-diameter portion 17, in other words, the small-diameter portion 16 having a low rigidity in which the constituent fibers 11 are present, the flexibility of the nonwoven fabric 1A is further improved, and the skin feel is further improved. In the non-woven fabric 1A, from the viewpoint of improving the feeling of the skin and the strength of the non-woven fabric, attention is paid to one constituent fiber 11, and it is preferable to have one or more large diameters between the adjacent fusion portions 12 and 12. The portion 17 is preferably one or more, and preferably has five or less, and more preferably three or less. Specifically, it is preferably one or more and five or less, and more preferably It has one or more and three or less.

The small-diameter portion 16 of the fiber diameter (L ₁₆₎ with respect to the large diameter portion 17 of the fiber diameter (L ₁₇₎ of the ratio (L ₁₆ / L ₁₇₎ is preferably 0.5 or more, and further preferably 0.55 or more, and more It is preferably 0.8 or less, more preferably 0.7 or less, and specifically preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less. Specifically, the fiber diameter (diameter L ₁₆ ) of the small-diameter portion 16 is preferably 5 μm or more, more preferably 6.5 μm or more, and particularly preferably 7.5, from the viewpoint of improving the feeling of the skin and reducing the strength of the nonwoven fabric. It is preferably not more than μm, more preferably 28 μm or less, further preferably 20 μm or less, and particularly preferably 16 μm or less, and specifically preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more, more preferably 13 μm or more, and particularly preferably 15 μm or more, and preferably 35 μm or less, from the viewpoint of improving the touch of the skin. It is preferably 25 μm or less, and particularly preferably 20 μm or less. Specifically, it is preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and still more preferably 15 μm or more and 20 μm or less.

The fiber diameters (diameters L ₁₆ and L ₁₇ ) of the small diameter portion 16 and the large diameter portion 17 were measured in the same manner as the measurement of the fiber diameter of the above fibers.

Moreover, the non-woven fabric of the present invention (first invention) is formed such that the hydrophilicity of the small-diameter portion 16 is smaller than the hydrophilicity of the large-diameter portion 17. In order to impart such a change in hydrophilicity to the fiber, the nonwoven fabric 1A may be produced in accordance with the following production method.

The "hydrophilicity" described in the first aspect of the present invention is determined based on the contact angle of the fibers measured by the method described below. Specifically, the lower hydrophilicity has the same meaning as the larger contact angle, and the higher hydrophilicity has the same meaning as the smaller contact angle.

[Method of measuring contact angle]

The constituent fibers 11 of the plurality of non-woven fabrics 1A are randomly selected, and the constituent fibers 11 having the small-diameter portion 16 and the large-diameter portion 17 are selected from the constituent fibers 11 to be extracted, and the position and size of the small-diameter portion 16 in the constituent fibers 11 are large. The contact angle of water at the position of the diameter portion 17 was measured. As the measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. was used. Distilled water was used for the measurement of the contact angle. The liquid amount ejected from the ink jet type water droplet ejecting portion (pulse ejector CTC-25 manufactured by Cluster Technology Co., Ltd., having a diameter of 25 μm) was set to 15 μL, and the water droplets were dropped to the position of the small diameter portion 16 and large. The positions of the diameter portions 17 are each located at the center of each. Record the dripping pattern on a high-speed video device connected to a horizontally-set camera. From the viewpoint of image analysis thereafter, the video apparatus is preferably a personal computer in which a high-speed pickup device is incorporated. In this assay, every 17 Msec is recording. In the recorded image, use the attached software FAMAS (software version is 2.6.2, analysis method is set to drop method, analysis method is set to θ/2 method, image processing algorithm is set to no reflection, image processing image The mode is set to the frame, and the threshold is set to 200, and the curvature correction is not performed. The image of the first image of the selected constituent fibers 11 is dropped on the water droplets, and the surface of the water contact with the fibers is calculated. The corner is set to the contact angle. The selected constituent fibers 11 were cut to a fiber length of about 1 mm, and the fibers were placed on a sample stage of the contact angle meter to maintain the level. The contact angles of the two different portions were measured for the small diameter portion 16 and the large diameter portion 17 of the one fiber. The contact angle of the small diameter portion 16 and the large diameter portion 17 of N=5 is measured to one decimal place, and the measured values of the total of 10 points are averaged, and the average value obtained is rounded to the first decimal place. The bit is defined as the contact angle of the small diameter portion 16 and the large diameter portion 17.

The difference between the contact angle of the small-diameter portion 16 and the contact angle of the large-diameter portion 17 (the former - the latter) is preferably 1 degree or more, from the viewpoint that the liquid residue on the surface of the nonwoven fabric 1A is small and the dryness of the touch is improved. In particular, it is 5 degrees or more, further 10 degrees or more, and is preferably 25 degrees or less, particularly 20 degrees or less, and further 15 degrees or less. For example, the difference in contact angle is preferably 1 degree or more and 25 degrees or less, more preferably 5 degrees or more and 20 degrees or less, and still more preferably 10 degrees or more and 15 degrees or less. Specifically, the contact angle of the small diameter portion 16 is preferably 60 degrees or more, particularly 70 degrees or more, more preferably 80 degrees or more, and is preferably 100 degrees or less, particularly 95 degrees or less, and further 90 degrees or less. For example, the contact angle of the small diameter portion 16 is preferably 60 degrees or more and 100 degrees or less, more preferably 70 degrees or more and 95 degrees or less, and still more preferably 80 degrees or more and 90 degrees or less. Further, the contact angle of the large diameter portion 17 is preferably 55 degrees or more, particularly 60 degrees or more, further 65 degrees or more, and preferably 90 degrees or less, particularly 85 degrees or less, and further 80 degrees or less. For example, the contact angle of the large diameter portion 17 is preferably 55 degrees or more and 90 degrees or less, more preferably 60 degrees or more and 85 degrees or less, and still more preferably 65 degrees or more and 80 degrees or less.

Further, as shown in FIG. 3, the non-woven fabric of the present invention (first invention) focuses on one of the constituent fibers 11 of the nonwoven fabric 1A, and is adjacent to the small-diameter portion 16 adjacent to the fusion portion 12. The change point 18 to the large diameter portion 17 is disposed within a range from the fusion portion 12 to one third of the interval T between the adjacent fusion portions 12 and 12. Here, the change point 18 of the non-woven fabric of the present invention (first invention) does not include the small diameter portion 16 extending from the smaller fiber diameter continuously to the fiber diameter larger than the small diameter portion 16 A portion where the large diameter portion 17 gradually changes or a portion that continuously changes to the large diameter portion 17 through a plurality of stages means a portion where the fiber diameter extremely changes. In the case where the one constituent fiber 11 is a core-sheath type composite fiber, the change point 18 of the nonwoven fabric of the present invention (first invention) does not include the first resin component and the constituent sheath constituting the core portion. The state in which the second resin component is separated from each other and the fiber diameter is changed means a portion where the fiber diameter is always changed by stretching.

Further, the change point 18 is disposed in a range from the fusion portion 12 to the 1/3 of the interval T between the adjacent fusion portions 12 and 12, and means that the constituent fibers 11 of the nonwoven fabric 1A are randomly selected and used. JCM-5100 (trade name) manufactured by JEOL Ltd., a scanning electron microscope, in which the constituent fibers 11 can be observed as shown in Fig. 3, and the adjacent fusion portions 12 and 12 of the fibers 11 are observed. (100 times to 300 times) to zoom in. Then, the distance T between the centers of the adjacent fusion portions 12 and 12 is divided into three equal parts, and is divided into a region AT on the side of the fusion portion 12, a region BT on the side of the other fusion portion 12, and a central region CT. Then, the change point 18 is placed in the above-described area AT or the above-described area BT. Further, the change point 18 is disposed in the non-woven fabric 1A in the range from the fusion portion 12 to the 1/3 of the interval T between the adjacent fusion portions 12 and 12, and means that 20 non-woven fabrics 1A are randomly selected. When the fibers 11 are formed, the constituent fibers 11 having the change points 18 in the region AT or the region BT have at least one nonwoven fabric in the 20 constituent fibers 11. Specifically, from the viewpoint of improving the feeling of touch, it is preferably one or more, more preferably five or more, and still more preferably 10 or more.

As described below, the non-woven fabric 1A of the present embodiment is extended not only by the side portion 13c but also the top portion 13a at the top of the ridge portion 13 and the bottom portion 13b at the bottom of the concave portion 14 The fiber density of the nonwoven fabric is reduced as compared with the raw material non-woven fabric before stretching. Thereby, the liquid permeability and air permeability of the nonwoven fabric 1A as a whole are improved. In the top portion 13a, the bottom portion 13b, and the side portion 13c, the side portion 13c is particularly easy to be stretched, and the fiber density is easily lowered. In the side portion 13c, the liquid permeability and the air permeability are particularly improved.

The non-woven fabric 1A of the present embodiment is formed such that the fiber density of the side portion 13c is smaller than the fiber density of the top portion 13a which is the top of the ridge portion 13, and the fiber density of the bottom portion 13b which is the bottom of the concave portion 14. Here, the fiber density means the fiber mass per unit volume of the nonwoven fabric 1A. The higher fiber density means that the amount of fibers per unit volume of the nonwoven fabric 1A is large, and the distance between the fibers is small. The lower fiber density means that the amount of fibers per unit volume of the nonwoven fabric 1A is small and the distance between the fibers is large. Further, the capillary strength is increased in the portion where the fiber density is high, and the capillary force is lowered in the portion where the fiber density is low.

When the non-woven fabric 1A is viewed in cross section as shown in Fig. 2, the nonwoven fabric 1A is such that the fiber density of the side portion 13c between the top portion (top portion 13a) of the ridge portion 13 and the bottom portion (bottom portion 13b) of the concave strip portion 14 is minimized. The way it is formed. Therefore, in the side portion 13c, the amount of fibers per unit volume of the nonwoven fabric 1A is minimized, the distance between fibers is maximized, and the air permeability of the nonwoven fabric 1A as a whole is improved and the liquid permeability is also improved. Further, by forming the fiber density of the side portion 13c to a minimum, the ridge portion 13 easily follows the movement of the wearer's skin, and a good skin feel can be achieved. In order to impart such a fiber density to the side portion 13c, the nonwoven fabric 1A may be produced in accordance with the following production method.

Lateral zones fiber density 13c of (D ₁₅₎ with respect to the fiber density (D ₁₃₎ at the top region 13a of the rate, or relative to the fiber density (D ₁₄₎ the bottom of the region 13b of the ratio _{(D 15 / D 13, D} 15 /D ₁₄ ) is preferably 0.15 or more, more preferably 0.2 or more, and is preferably 0.9 or less, further preferably 0.8 or less, specifically, preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more. And 0.8 or less. Further, regarding the specific value of the fiber density of the nonwoven fabric 1A, the fiber density (D ₁₃ ) of the top portion 13a is preferably 80 pieces/mm ² or more, further preferably 90 pieces/mm ² or more, and preferably 200 pieces / Mm ² or less is more preferably 180 pieces/mm ² or less, and specifically, preferably 80 pieces/mm ² or more and 200 pieces/mm ² or less, and more preferably 90 pieces/mm ² or more and 180 pieces / Below mm ² . Further, the fiber density (D ₁₄ ) of the bottom portion 13b is preferably 80 pieces/mm ² or more, further preferably 90 pieces/mm ² or more, and more preferably 200 pieces/mm ² or less, and further preferably 180 pieces. / mm ² or less, specifically, is preferably 80 / mm ² or more and 200 / mm ² or less, further preferably 90 / mm ² or more and 180 / mm ² or less. Further, the fiber density (D ₁₅ ) of the side portion 13c is preferably 30 pieces/mm ² or more, more preferably 40 pieces/mm ² or more, and further preferably 80 pieces/mm ² or less, and further preferably 70 pieces. The root/mm ² or less is specifically 30 pieces/mm ² or more and 80 pieces/mm ² or less, and more preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less. The fiber density of the top portion 13a is measured at a position near the apex of the ridge portion 13. The fiber density of the bottom portion 13b is measured at a position near the bottom point of the concave portion 14. The method for measuring the fiber density is as follows.

[Method for Measuring Fiber Density of Top Zone 13a, Bottom Zone 13b or Side Zone 13c]

The nonwoven fabric was cut with a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and the fiber density of the top region 13a was measured by using a scanning electron microscope, and the thickness of the cut surface of the nonwoven fabric was 3 in the Z direction. The upper part of the time division, that is, the vicinity of the apex of the ridge portion 13 is magnified and observed (adjusted to measure the magnification of the fiber profile of 30 to 60 fibers; 150 to 500 times), by the above-mentioned area (0.5 mm ² ) Cut the surface and count the number of sections of the cut fiber. Then, the number of sections of the fiber per 1 mm ^{2 was} converted into the fiber density of the top portion 13a. The measurement was carried out at three locations, and averaged and set as the fiber density of the sample. In the same manner, the fiber density of the bottom portion 13b is determined by measuring the vicinity of the bottom point of the concave portion 14 when the thickness of the cut surface of the nonwoven fabric is equally divided in the Z direction by three. Similarly, the fiber density of the side portion 13c is determined by measuring the center portion when the thickness of the cut surface of the nonwoven fabric is equally divided in the Z direction by three. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

Further, in the nonwoven fabric 1A of the present embodiment, the number of fibers having the change point 18 among the constituent fibers constituting the side portion 13c is larger than the number of fibers having the change point 18 among the constituent fibers of the top portion 13a and the bottom portion 13b. The way is formed. Thereby, the top region 13a becomes easy to follow the movement of the wearer's skin, and a good skin feel can be achieved. The ratio of the number of fibers (N ₁₅ ) having the change point 18 in the constituent fibers constituting the side portion 13c to the number of fibers (N ₁₃ ) having the change point 18 among the constituent fibers constituting the top portion 13a, or relative to the constitution The ratio (N ₁₅ /N ₁₃ , N ₁₅ /N ₁₄ ) of the number of fibers (N ₁₄ ) having the change point 18 in the constituent fibers of the bottom portion 13b is preferably 2 or more, more preferably 5 or more, and is preferably. It is 20 or less, more preferably 20 or less, and specifically, it is preferably 2 or more and 20 or less, and more preferably 5 or more and 20 or less. Further, regarding the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1A, the number of fibers (N ₁₃ ) having the change point 18 among the constituent fibers constituting the top portion 13a is preferably one or more, and more preferably 5 or more. The roots are preferably 15 or less, more preferably 15 or less, and specifically preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less. Further, the number of fibers (N ₁₄ ) having a change point 18 in the constituent fibers constituting the bottom portion 13b is preferably one or more, more preferably five or more, and preferably 15 or less, and more preferably 15 or less. Specifically, the roots are preferably one or more and 15 or less, and more preferably five or more and 15 or less. Further, the number of fibers (N ₁₅ ) having the change point 18 in the constituent fibers constituting the side portion 13c is preferably 5 or more, more preferably 10 or more, and still preferably 20 or less, and further preferably 20 or less, specifically, it is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method of measuring the number of fibers having the change point 18 is as follows.

[Method for Measuring the Number of Fibers Having Change Point 18 among the constituent fibers of the top portion 13a, the bottom portion 13b, or the side portion 13c]

The number of fibers having the change point 18 in the constituent fibers 11 constituting the top portion 13a is enlarged by the scanning electron microscope, and the vicinity of the apex portion of the ridge portion 13 when the thickness of the nonwoven fabric is equally divided in the Z direction is enlarged. Observation (adjusted to measure 30~60 fibers The ratio of the fiber profile of the dimension is 50 to 500 times, and 20 constituent fibers 11 constituting the top portion 13a are randomly selected, and the number of fibers having the change point 18 in the constituent fibers 11 is counted. When there is one or more change points 18 between the fusion portions, the number of fibers having the change point 18 is set to be one, and when there are a plurality of fibers, the number is also one. This is taken as the number of fibers having the change point 18 among the constituent fibers constituting the top portion 13a. The measurement was carried out at three locations, and the average was made into the number of fibers having the change point 18 among the constituent fibers constituting the top portion 13a of the sample. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom portion 13b is measured in the vicinity of the bottom point of the concave portion 14 when the thickness of the nonwoven fabric is equally divided in the Z direction by three. Out. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the side portion 13c is determined by measuring the center portion when the thickness of the nonwoven fabric is equally divided in the Z direction by three. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

The nonwoven fabric 1A of the present embodiment can be used, for example, for a front sheet having a skin facing surface side, a back sheet disposed on the non-skin opposing surface side, and a disposable body interposed between the two sheets. Absorbent articles such as diapers or sanitary napkins. In particular, the front sheet of the constituent member of the absorbent article may be formed of the nonwoven fabric 1A, or the liquid permeable sublayer disposed between the front sheet and the absorbent body may be formed of the nonwoven fabric 1A. When the front sheet is formed of the nonwoven fabric 1A, since the nonwoven fabric 1A is a non-woven fabric having a concavo-convex structure, the contact area ratio with the skin is lowered, and friction is more difficult to occur. In addition, when the nonwoven fabric 1A is formed of the nonwoven fabric 1A, the nonwoven fabric 1A is a non-woven fabric having a concavo-convex structure, so that the compression resistance is improved, the cushioning feeling is improved, and the backwash of the body fluid can be prevented.

Regarding the thickness of the nonwoven fabric 1A, the overall thickness of the nonwoven fabric 1A when viewed from the side is the sheet thickness T _S , and the partial thickness of the nonwoven fabric 1A which is bent by the unevenness is defined as the layer thickness T _L . The sheet thickness T _{S may} be appropriately adjusted according to the use, and is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 7 mm or less when used as a front sheet or a secondary layer of an absorbent article. More preferably, it is 5 mm or less, and specifically, it is preferably 0.5 mm or more and 7 mm or less, more preferably 1 mm or more and 5 mm or less. By setting it as this range, the body fluid absorption rate at the time of use is accelerated, and the liquid return of the self-absorber can be suppressed, and the moderate cushioning property can be implement|achieved.

The layer thickness T _L may be different in each portion in the nonwoven fabric 1A, and may be appropriately adjusted according to the use. When used as a front sheet or a sub-layer of an absorbent article, the layer thickness T _{L1 of the} top portion 13a is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, specifically, it is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L2 of the} bottom portion 13b is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, and specifically, preferably 0.1 mm or more and 3.0 mm. Hereinafter, it is more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L3 of the} side portion 13c is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, and specifically, preferably 0.1 mm or more and 3.0. Below mm, more preferably 0.2 mm or more and 2.0 mm or less. By setting it as this range, the body fluid absorption rate at the time of use is accelerated, and the liquid return of the self-absorber can be suppressed, and the moderate cushioning property can be implement|achieved.

The sheet thickness T _S and the layer thickness T _L were measured by the following methods.

The measurement method of the sheet thickness T _S was carried out using a thickness measuring device while applying a load of 0.05 kPa to the nonwoven fabric 1A. The thickness gauge is a laser displacement meter manufactured by Omron. In the thickness measurement system, 10 points were measured, and the average value of these was calculated and made into thickness.

The layer thickness T _L was measured by a digital microscope VHX-900 manufactured by KEYENCE Co., Ltd., and the thickness of each layer was measured by magnifying the cross section of the sheet by about 20 times.

When the non-woven fabric 1A is viewed from above, the distance between the adjacent top regions 13a in the Y direction may be appropriately adjusted according to the use, and when used as a front sheet or a sub-layer of an absorbent article, it is preferably 1 mm or more. Preferably, it is 1.5 mm or more, and preferably 15 mm. More preferably, it is 10 mm or less, and specifically, it is preferably 1 mm or more and 15 mm or less, more preferably 1.5 mm or more and 10 mm or less.

Further, the basis weight of the nonwoven fabric 1A also depends on the specific use of the nonwoven fabric 1A, and in the case of being used as the front sheet or the secondary layer of the absorbent article, it is preferably 15 g/m ² or more based on the average value of the entire sheet. More preferably, it is 20 g/m ² or more, and is preferably 50 g/m ² or less, more preferably 40 g/m ² or less, and specifically, preferably 15 g/m ² or more and 50 g/m ² or less, more preferably It is 20 g/m ² or more and 40 g/m ² or less.

Further, a fiber treatment agent is adhered to the surface of the constituent fiber 11 of the nonwoven fabric 1A. More preferably, in the raw material stage, a fiber treating agent is adhered to the surface of the high-stretch fiber constituting the fiber 11. The fiber treating agent preferably contains a ductile component, and further preferably contains a ductile component and a hydrophilic component. Here, the component having ductility means a component which is easily spread on the surface of the fiber at a low temperature and has excellent fluidity at a low temperature when it adheres to the surface of the fiber. As such a ductile component, a polyoxyxylene resin having a low glass transition point and a flexible molecular chain is exemplified, and as the polyfluorene oxide resin, a Si-O-Si chain as a main chain can be preferably used. Polyorganosiloxane. When the fiber treatment agent attached to the surface of the fiber contains a ductile component and a hydrophilic component, the ductile component is easily spread when the fiber is stretched, and the hydrophilic component is difficult to expand, whereby the fiber is difficult to expand. The hydrophilicity of the extension changes.

In addition, the "fiber treatment agent" which is based on the content of the fiber treatment agent-containing component as a component having ductility is "the fiber treatment agent attached to the nonwoven fabric" unless otherwise specified, and is not attached to the nonwoven fabric. Fiber treatment agent. When the fiber treatment agent is adhered to the uneven fabric, the fiber treatment agent is usually diluted with a suitable solvent such as water. Therefore, the fiber treatment agent contains the content of the component, for example, a component having ductility in the fiber treatment agent. The content in the middle can be based on the total mass of the diluted fiber treating agent.

Moreover, whether or not it is a component having ductility is judged as follows. Specifically In other words, the fiber treatment agent to be judged is applied to the surface of the high-stretch fiber having no fiber treatment agent, and the hydrophilicity of the high-stretch fiber to which the fiber treatment agent is imparted is measured based on the above [measurement method of contact angle]. . Then, the high-stretch fiber to which the fiber treatment agent is applied is extended by 2.0 times to form the small-diameter portion 16 and the large-diameter portion 17. Then, based on the above [measurement method of contact angle], the hydrophilicity of the formed large diameter portion 17 is measured. Further, when the difference between the hydrophilicity of the high-stretch fiber before the measurement and the hydrophilicity of the large-diameter portion 17 measured is 10 degrees or more, it is determined that the component of the fiber treatment agent is ductile. The ingredients. In other words, the constituent fibers 11 having the small diameter portion 16 and the large diameter portion 17 are selected from the constituent fibers of the nonwoven fabric 1A, and the position and the large diameter portion 16 of the constituent fibers 11 are large based on the above [measurement method of the contact angle]. The contact angle of water at the position of the diameter portion 17 was measured. When the difference between the contact angle of the small diameter portion 16 to be measured and the contact angle of the large diameter portion 17 to be measured is 10 degrees or more, it is determined that the fiber treatment agent contains a ductile component. In the case where the constituent fibers of the non-woven fabric used for the products such as diapers are commercially available, the target nonwoven fabric is peeled off from the product, and the treatment agent is extracted with an ethanol or ethanol/methanol mixed solvent to carry out component analysis. Then, the above-described measurement was performed on the identified components, and it was judged whether or not each component was a ductile agent.

As the polyorganosiloxane, any one of a linear one having a crosslinked two-dimensional or three-dimensional network structure can be used. It is preferably a substantially linear one.

As a preferred example of the polyorganooxane, a polymer of an alkyl alkoxy decane or an aryl alkoxy decane, an alkyl halo oxane or a cyclic decane is used as the alkoxy group. Base, typically methoxy. The alkyl group is preferably an alkyl group which may have a side chain of 1 or more and 18 or less, preferably 1 or more and 8 or less, especially 1 or more and 4 or less. As the aryl group, a phenyl group, an alkylphenyl group, an alkoxyphenyl group or the like can be exemplified. It may also be a cyclic hydrocarbon group such as a cyclohexyl group or a cyclopentyl group, or an aralkyl group such as a benzyl group, in place of an alkyl group or an aryl group.

Preferred examples of the polyorganooxynonane which are most preferable include polydimethyl methoxy olefin, polydiethyl decane, polydipropyl decane, and the like, and more preferably polydimethyl siloxane.

The molecular weight of the polyorganosiloxane is preferably a high molecular weight, and specifically, it is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, and preferably 100, in terms of weight average molecular weight. More than 10,000, more preferably 800,000 or less, and even more preferably 600,000 or less. Further, as the polyorganosiloxane, two or more kinds of polyorganosiloxanes having different molecular weights may be used. When two or more kinds of polyorganosiloxanes having different molecular weights are used, the weight average molecular weight of one of them is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, and further preferably It is 1,000,000 or less, more preferably 800,000 or less, further preferably 600,000 or less, and the other weight average molecular weight is preferably less than 100,000, more preferably 50,000 or less, and even more preferably 35,000 or less. Further, it is preferably 20,000 or less, more preferably 2,000 or more, still more preferably 3,000 or more, still more preferably 5,000 or more. Further, a preferred blending ratio of the polyorganosiloxane having a weight average molecular weight of 100,000 or more to a polyorganosiloxane having a weight average molecular weight of less than 100,000 (the former: the latter) is preferably 1:10 to 4 by mass ratio. :1, more preferably 1:5~2:1.

The weight average molecular weight of the polyorganosiloxane is measured by GPC (gel permeation chromatography). The measurement conditions are as follows. Further, the calculation of the converted molecular weight is carried out in polystyrene.

Separation column: GMHHR-H+GMHHR-H (cation)

Dissolution: L Farmin DM20/CHCl ₃

Solvent flow rate: 1.0ml/min

Separation column temperature: 40 ° C

The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 30% by mass or less, from the viewpoint of greatly changing the hydrophilicity of the fiber. Further, it is preferably 20% by mass or less. Specifically, the content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.

As the polyorganosiloxane, a commercially available product can also be used. For example, Shin-Etsu Chemical Industry Co., Ltd. "KF-96H-100M Cs" manufactured by Co., Ltd., "SH200 Fluid 1000000Cs" manufactured by Toray-Dow Corning Co., Ltd., and, as a product containing two kinds of polyorganosiloxanes, can be manufactured by Shin-Etsu Chemical Co., Ltd. "KM-903" or "BY22-060" manufactured by Toray-Dow Corning Co., Ltd.

As the hydrophilic component, a zwitterionic surfactant or a nonionic surfactant can be used.

Examples of the amphoteric ionic surfactant include an alkyl group (having 1 to 30 carbon atoms) of a betaine, an alkyl group (having a carbon number of 1 to 30), a decylalkyl group (carbon number 1 to 4), dimethylbetaine. Alkaloid (carbon number 1 to 30) dihydroxyalkyl (carbon number 1 to 30) betaine, sulfobetaine type amphoteric surfactant, etc., betaine type zwitterionic surfactant, or alanine type [alkane Base (carbon number 1 to 30) aminopropionic acid type, alkyl group (carbon number 1 to 30) imine dipropionic acid type, etc.] amphoteric surfactant, alkyl betaine and other glycine type [alkyl ( Amino acid type amphoteric surfactant such as amphoteric surfactant, and amino acid sulfonic acid type amphoteric surfactant such as an amphoteric surfactant such as a carbon number of 1 to 30) . Among them, a betaine-type amphoteric surfactant is preferred, and an alkyl (carbon number: 1 to 30) betaine is preferred, and an alkylbetaine having a carbon number of 16 to 22 (e.g., stearyl) is preferred.

Examples of the nonionic surfactant include polyglycerol fatty acid esters such as glycerin fatty acid esters, poly (preferably n = 2 to 10) glycerin fatty acid esters, and sorbitan fatty acid esters. It is a fatty acid having a carbon number of 8 to 60), a polyoxyalkylene group (additional molar number of 2 to 20), an alkyl group (carbon number of 8 to 22), a polyamine alkyl group (additional molar number 2~) 20) an alkyl group (carbon number 8 to 22) ether, a polyoxyalkylene group-modified polyfluorene oxide, an amine group modified polyoxane, and the like.

The fiber treatment agent preferably contains a hydrophobic component in addition to a component having ductility and a hydrophilic component. The hydrophobic component may, for example, be an alkyl phosphate or an anionic surfactant represented by the following formula (1) (hereinafter also simply referred to as "anionic surfactant").

[Chemical 1]

(wherein Z represents a linear or branched alkyl chain having 1 to 12 carbon atoms which may include an ester group, a mercaptoamine group, an amine group, a polyoxyalkylene group, an ether group or a double bond, and R ₁ and R ₂ independently represents a linear or branched alkyl group having 2 to 16 carbon atoms which may include an ester group, a mercaptoamine group, a polyoxyalkylene group, an ether group or a double bond, and X represents -SO ₃ M, -OSO ₃ M or -COOM, M means H, Na, K, Mg, Ca or ammonium)

The alkyl phosphate is formulated in a fiber treating agent in order to improve the properties of the carding machine of the raw cotton or the uniformity of the fiber web, thereby improving the productivity of the nonwoven fabric and preventing the deterioration of the quality. Specific examples of the alkyl phosphate include those having a saturated carbon chain such as stearyl phosphate, myristyl phosphate, lauryl phosphate, and palmitate phosphate; or unsaturated esters such as phosphoric acid ester and myristyl phosphate. Carbon chains, and those having side chains in such carbon chains. More preferably, it is a fully neutralized or partially neutralized salt having a carbon chain of 16 to 18 mono or dialkyl phosphates. In addition, examples of the salt of the alkyl phosphate include an alkali metal such as sodium or potassium, ammonia, various amines, and the like. The alkyl phosphate may be used singly or in combination of two or more.

The blending ratio of the alkyl phosphate is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of the passability of the card or the uniformity of the fiber web, and the like, and does not hinder the generation based on the heat treatment. From the viewpoint of hydrophobization of the fibers formed of the polyorganosiloxane, it is preferably 30% by mass or less, and more preferably 25% by mass or less.

The content ratio of the polyorganosiloxane and the alkyl phosphate in the fiber treating agent (the former: the latter) is preferably from 1:5 to 10:1, more preferably from 1:2 to 3:1, in terms of mass ratio.

The anionic surfactant represented by the above formula (1) means a component which does not contain the above alkyl phosphate. Further, the anionic surfactant represented by the above formula (1) can be used alone It is used in one type or in mixture of two or more types.

The above-mentioned anionic surfactant in which X in the formula (1) is -SO ₃ M, that is, the hydrophilic group is a sulfonic acid or a salt thereof, may, for example, be a dialkylsulfonic acid or a salt thereof. Specific examples of the dialkylsulfonic acid include di(octadecyl)sulfosuccinic acid, dimercaptosulfosuccinic acid, ditridecylsulfosuccinic acid, and di(2-ethylidene). a compound obtained by esterifying a dicarboxylic acid with a dialkyl sulfosuccinic acid such as sulfosuccinic acid or a dialkyl sulfosuccinic acid, and sulfonating the α-position of the diester; or 2- Sodium sulfotetradecanoate 1-ethyl ester (or decylamine) sodium salt or 2-sulfohexadecanoic acid 1-ethyl ester (or decylamine) sodium salt or the like to saturate a fatty acid or an unsaturated fatty acid ester ( Or a sulfonated fatty acid alkyl ester (or guanamine) which is sulfonated at the alpha position of the guanamine; or a dialkyl obtained by sulfonating the internal olefin of the hydrocarbon chain or the internal olefin of the unsaturated fatty acid. Base olefin sulfonic acid, etc. The number of carbon atoms of each of the two alkyl groups of the dialkylsulfonic acid is preferably 4 or more and 14 or less, particularly preferably 6 or more and 10 or less.

The above anionic surfactant which is a sulfonic acid or its salt as a hydrophilic group, more specifically, the following anionic surfactant is mentioned.

The above-mentioned anionic surfactant in which X in the formula (1) is -SO ₃ M, that is, the hydrophilic group is sulfuric acid or a salt thereof, may, for example, be a dialkyl sulfate. Specific examples thereof include a 2-ethyl sulfate a compound obtained by sulfating a branched alcohol such as sodium hexyl hexate or sodium 2-hexyl sulphate; or polyoxyethylene 2-hexyl decyl sulfate or polyoxyethylene 2-hexyl decyl sulfate a compound having a POE chain introduced between a branched alcohol and a sulfate group; or 1-sulfate-l-methyl stearate (or decylamine) 3-sulfate-hexanoic acid 1-methyl ester (or hydrazine) A compound obtained by sulfating a hydroxy fatty acid ester (or guanamine), etc., such as an amine.

The above anionic surfactant which is a hydrophilic group of sulfuric acid or its salt, more specifically, the following anionic surfactant is mentioned.

[Chemical 4]

The above-mentioned anionic surfactant in which X in the formula (1) is -COOM, that is, the hydrophilic group is a carboxylic acid or a salt thereof, may, for example, be a dialkylcarboxylic acid, and specific examples thereof include 11-ethoxy group. a sodium heptadecanecarboxylate or a sodium salt of 2-ethoxypentacarboxylate, etc. alkoxylate a hydroxyl moiety of a hydroxy fatty acid and sodium to form a compound; or an amine such as sarcosine or glycine a compound in which an amine group of a base acid is reacted with an alkoxylated hydroxy fatty sulfonium chloride to thereby sodiumify a carboxylic acid of an amino acid moiety; or an amine group of arginine is reacted with a fat ruthenium chloride And the obtained compound and the like.

The above anionic surfactant which is a carboxylic acid or a salt thereof as a hydrophilic group, more specifically, the following anionic surfactant is mentioned.

[Chemical 5]

The blending ratio of the anionic surfactant represented by the formula (1) is preferably 1% by mass or more, more preferably 5% by mass or more, and if the hydrophilicity is too high, the liquid is easily stored and the drying property is impaired. From this viewpoint, it is preferably 20% by mass or less, and more preferably 13% by mass or less. In addition, the above-mentioned blending ratio of the anionic surfactant represented by the formula (1) is preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 13% by mass or less.

The content ratio of the polyorganosiloxane in the fiber treating agent to the anionic surfactant represented by the formula (1) (the former: the latter) is preferably from 1:3 to 4:1 by mass ratio, more preferably 1:2~3:1.

Further, in addition to the ductile component, the hydrophilic component, the alkyl phosphate, and the anionic surfactant, the fiber treating agent may be an anionic surfactant or a cationic surfactant.

Examples of the anionic surfactant include sodium alkyl phosphate, sodium alkyl phosphate, sodium dialkyl phosphate, sodium dialkyl sulfosuccinate, and benzene. Sodium sulfonate sodium salt, sodium sulfonate sodium salt, sodium alkyl sulfate salt, sodium salt of a second alkyl sulfate, etc. (Alkyl groups are preferably a carbon number of 6 or more and 22 or less, especially 8 Above and below 22). These may also use other alkali metal salts such as potassium salts instead of the sodium salt.

Examples of the cationic surfactant include halogenated alkyl (or alkenyl) trimethylammonium, halogenated dialkyl (or alkenyl) dimethyl ammonium, halogenated alkyl (or alkenyl) pyridinium, and the like. These compounds are preferably those having an alkyl group or an alkenyl group having 6 or more and 18 or less carbon atoms. Examples of the halogen in the halogen compound include chlorine, bromine, and the like.

Further, a treatment agent such as a gel-preventing agent such as a modified polyfluorene oxide, a fiber coloring agent, or a lubricant may be further added to the fiber treating agent.

As a method of attaching the fiber treating agent to the surface constituting the fiber 11, various known methods can be employed without particular limitation. For example, spray coating, application by a slit coater, application by roll transfer, immersion in a fiber treatment agent, etc. are mentioned. These treatments may be carried out on the fibers before the fiber webization, or after the fibers are networked by various methods. However, it must be processed before the extension processing described below. The fiber to which the fiber treatment agent is adhered on the surface is dried, for example, by a hot air blow dryer at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C or lower).

The non-woven fabric of the present invention (first invention) is produced by a method for producing a non-woven fabric having a step of fusing a cross-section of constituent fibers of a fiber web including a high-stretch fiber having a fiber-treating agent. a heat fusion process; and an extending step of extending the fiber web in the one side after the fusion step. In one embodiment of the method for producing a nonwoven fabric according to the present invention (first invention), a preferred manufacturing method of the nonwoven fabric 1A will be described as an example, and will be described with reference to FIG. In Fig. 4, a preferred manufacturing apparatus 100 used in the manufacturing method of the nonwoven fabric 1A is schematically shown. The manufacturing apparatus 100 can be preferably used by a manufacturer of hot air non-woven fabrics. The manufacturing apparatus 100 is provided with the web forming part 200, the hot air processing part 300, and the extension part 400 in order from the upstream side of the manufacturing process to the downstream side.

As shown in FIG. 4, the web forming part 200 is provided with the web forming apparatus 201. As the web forming device 201, a carding machine can be used. As the card, the same as the card generally used in the technical field of absorbent articles can be used without particular limitation. Depending on the specific use of the nonwoven fabric 1A, other web manufacturing equipment, such as an air spinning device, may be used instead of the carding machine.

As shown in FIG. 4, the hot air processing unit 300 is provided with a filter cover 301. In the filter cover 301, hot air can be blown by hot air. Further, the hot air treatment unit 300 includes a belt 302 having a ring shape including a permeable mesh. A conveyor belt 302 surrounds the filter housing 301. The conveyor belt 302 is formed of a resin such as polyethylene terephthalate or a metal.

The temperature of the hot air blown into the filter 301 and the heat treatment time are preferably adjusted so that the intersection of the high-stretch fibers contained in the constituent fibers 11 of the fiber web 10 is thermally fused. Specifically, the temperature of the hot air is preferably adjusted to a temperature of 0 ° C to 30 ° C higher than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 10 . The heat treatment time is preferably adjusted to 1 second to 5 seconds depending on the temperature of the hot air. Further, from the viewpoint of promoting further entanglement of the constituent fibers 11 with each other, the wind speed of the hot air is preferably about 0.3 m/sec to 1.5 m/sec. Further, the conveying speed is preferably about 5 m/min to 100 m/min.

As shown in FIGS. 4 and 5, the extending portion 400 is provided with a pair of uneven rollers 401 and 402 that can mesh with each other. The pair of uneven rollers 401 and 402 are formed to be heatable, and are formed by alternately arranging the large-diameter convex portions 403 and 404 and the small-diameter concave portions (not shown) in the roller axis direction. The embossing rolls 401 and 402 can be heated or not, and the high-stretch fibers included in the constituent fibers 11 of the fiber sheet 1a described below can be easily heated in the case of heating the embossing rolls 401 and 402. The temperature is preferably set to be greater than or equal to the melting point of the resin having the highest glass transition point in the high elongation fiber and the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, it is higher than the temperature at which the glass transition point of the fiber is 10 ° C or higher and 10 ° C lower than the melting point, and further preferably higher than the temperature of the glass transition point of the fiber by 20 ° C or higher and lower than the melting point by 20 ° C. . For example, the fiber is used as a core/sheath construction When the fiber has a glass transition point of 67 ° C, a melting point of 258 ° C, a PET (core) / glass transition point of -20 ° C, and a melting point of 135 ° C PE (sheath), it is preferably heated to 67 ° C or higher. 135 ° C or less is more preferably heated to 77 ° C or more and 125 ° C or less, and further preferably heated to 87 ° C or more and 115 ° C or less.

Further, as shown in FIG. 6, in the manufacturing apparatus 100, the interval (pitch) between the large-diameter convex portions 403 and 403 adjacent to each other in the roll axis direction of the uneven roller 401, and the roll axis direction of the uneven roller 402 are shown. The interval (pitch) between the adjacent large-diameter convex portions 404 and 404 is the same interval (pitch) w, and the high-stretch fibers contained in the constituent fibers 11 of the fiber sheet 1a are smoothly stretched in the stretching device. The distance (pitch) w is preferably 1 mm or more, and more preferably 1.5 mm or more, from the viewpoint that the change point from the small diameter portion to the large diameter portion is adjacent to the fusion portion and the skin feel is good. It is preferably 10 mm or less, and particularly preferably 8 mm or less. Specifically, it is preferably 1 mm or more and 10 mm or less, and more preferably 1.5 mm or more and 8 mm or less. From the same viewpoint, as shown in FIG. 6, the pressing amount t of the pair of uneven rollers 401, 402 (the apex of the large-diameter convex portion 403 adjacent to the roller axis direction and the apex of the large-diameter convex portion 404) The interval) is preferably 1 mm or more, more preferably 1.2 mm or more, and is preferably 3 mm or less, more preferably 2.5 mm or less, and specifically, preferably 1 mm or more and 3 mm or less, particularly preferably 1.2 mm or more and 2.5. Below mm. Further, from the same viewpoint, the mechanical stretching ratio is preferably 1.5 times or more, more preferably 1.7 times or more, and is preferably 3.0 times or less, particularly preferably 2.8 times or less, and specifically, preferably 1.5 times. The above is 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

A method of manufacturing the nonwoven fabric 1A using the manufacturing apparatus 100 having the above configuration will be described.

First, as shown in FIG. 4, in the web forming portion 200, a short fiber-like constituent fiber 11 having a high-stretching fiber to which a fiber treating agent has been applied is used as a raw material, and a web forming apparatus 201 as a carding machine is used. The web 10 is formed (web forming step). The web 10 manufactured by the web forming apparatus 201 is in a state where the constituent fibers 11 are relaxed from each other. The state of the ground complex has not yet obtained the shape retention as a sheet.

Then, as shown in FIG. 4, the intersection of the constituent fibers 11 of the fiber web 10 including the high-stretch fibers is thermally fused via the fusion portion 12 to form the fiber sheet 1a (fusion step). Specifically, the fiber web 10 is conveyed to the conveyor belt 302, and the hot air is blown by hot air while the hot air processing unit 300 passes through the filter 301. When the hot air is blown by the hot air, the fibers 11 of the fiber web 10 are further entangled with each other, and the intersection of the fibers to be entangled is thermally fused (see FIG. 7(a)) to produce a sheet-like shape. Shaped fibrous sheet 1a.

Then, as shown in Fig. 4, the fused fiber web 1a is extended in one direction (extension step). Specifically, the fused fiber web 1a having the shape retaining property as a sheet is conveyed between the pair of embossing rolls 401 and 402, and as shown in FIGS. 7(a) to 7(c), the web is made. 1a is extended, and a large-diameter portion 17 having a large fiber diameter sandwiched by two small-diameter portions 16 and 16 having a small fiber diameter is formed in one of the constituent fibers 11 between the adjacent fusion portions 12 and 12. The change point 18 from the small diameter portion 16 to the large diameter portion 17 is formed in a range from the fusion portion 12 to a distance 1/3 between the fusion portions 12 and 12 adjacent thereto. As will be described in detail, the fiber sheet 1a which is thermally fused at the intersection of the constituent fibers 11 via the fusion portion 12 is transferred between the pair of embossing rolls 401 and 402 as shown in Fig. 7(a) to form the web 1a. It extends in an orthogonal direction (CD, roller direction) orthogonal to the machine direction (MD, traveling direction). When the fiber sheet 1a is extended in the orthogonal direction (CD, roll direction), as shown in Fig. 7(a), the regions where the constituent fibers 12 and 12 are adjacent to each other are fixed to each other. It is actively stretched in the orthogonal direction (CD, roll axis direction). In particular, as shown in Fig. 7(b), in the vicinity of the respective fused portions 12 where the constituent fibers 11 are fixed to each other, first, partial shrinkage is likely to occur, and one of the adjacent fusion-welded portions 12 and 12 constitutes the fibers 11, Two small diameter portions 16 and 16 are formed at both ends, and a portion sandwiched by the two small diameter portions 16 and 16 is a large diameter portion 17 to form a large diameter portion sandwiched by the two small diameter portions 16 and 16. 17. As described above, in the vicinity of each of the fusion portions 12, local contraction is likely to occur first, and thus the change point 18 from the small diameter portion 16 to the large diameter portion 17 is shaped. It is in the range from the fusion portion 12 to the 1/3 of the interval T between the fusion portions 12 and 12 adjacent thereto.

Further, one of the constituent fibers 11 between the adjacent ones of the welded portions 12 and 12 is in the orthogonal direction in a state where the stretchable space (elongation space) remains as shown in FIG. 7(c) ( The CD (roller axis direction) is further extended to extend the large diameter portion 17 between the adjacent fusion portions 12 and 12, and the small diameter portion 16 is formed in the large diameter portion 17.

When the region between the adjacent fused portions 12 and 12 adjacent to one of the constituent fibers 11 is actively stretched, the component having a ductility in the fiber treating agent attached to the surface constituting the fiber 11 is low in temperature. Since it is excellent in fluidity, it flows in accordance with the elongation of the fiber, and maintains the state of adhering to the surface of the small-diameter portion 16. On the other hand, when the components other than the component having the ductility in the fiber treatment agent attached to the surface of the fiber 11 are actively stretched in the region between the adjacent fusion portions 12 and 12, As the fiber flows, the state of adhering to the surface of the small diameter portion 16 cannot be maintained. Therefore, the composition ratio of the attached fiber treatment agent changes by the surface of the small diameter portion 16 formed by extending the region between the adjacent fusion portions 12 and 12 and the surface of the large diameter portion 17. Specifically, on the surface of the small-diameter portion 16, only the component having ductility is likely to adhere, and on the other hand, a fiber treatment agent containing a ductile component and a hydrophilized component adheres to the surface of the large-diameter portion 17. Therefore, the hydrophilicity of the small diameter portion 16 is likely to be smaller than the hydrophilicity of the large diameter portion 17. In particular, when the polyorganosiloxane is used as the component having ductility, since the polyorganosiloxane itself is hydrophobic, the hydrophilicity of the small-diameter portion 16 is more likely to be less than the hydrophilicity of the large-diameter portion 17.

As described above, according to the manufacturing method of the nonwoven fabric 1A using the manufacturing apparatus 100, the nonwoven fabric having the constituent fibers 11 shown in FIG. 3 and having the hydrophilicity of the small-diameter portion 16 smaller than the hydrophilicity of the large-diameter portion 17 can be continuously and efficiently produced. 1A. As shown in Fig. 4, the produced non-woven fabric 1A was temporarily taken up and stored in the form of a roll, and then used by being rolled up from the roll. Alternatively, the processing is performed on the subsequent production line of the manufacturing apparatus 100 of the non-woven fabric 1A, thereby continuously manufacturing the mesh. Standard products.

As shown in FIG. 3, the non-woven fabric 1A manufactured as described above is focused on one of the constituent fibers 11 constituting the fiber 11, and is disposed from the small-diameter portion 16 adjacent to the fusion portion 12 to the change point 18 of the large-diameter portion 17. In the range from the fusion portion 12 to the 1/3 of the distance T between the adjacent fusion portions 12 and 12, it becomes soft and the skin feel is good. In particular, attention is paid to one constituent fiber 11. When a plurality of small diameter portions 16 are formed between adjacent fusion portions 12 and 12, the skin feel is better. From the viewpoint of easily exhibiting such an effect, the constituent fibers 11 preferably contain only high-stretch fibers.

When the elastic fibers are incorporated in the constituent fibers 11, the nonwoven fabric is stretched while being shrunk. Therefore, even when the manufacturing method and the mechanical stretching ratio of the nonwoven fabric 1A are the same, it is difficult to cause a change in the fiber diameter. Therefore, when the elastic fiber is incorporated in the constituent fiber 11, it is difficult to form a portion 18 which is a portion where the fiber diameter is extremely changed, and it is easy to form a portion which gradually changes from the small-diameter portion 16 to the large-diameter portion 17. Due to the incorporation of the elastic fibers, the continuously gradually changing portions thus formed do not necessarily locally extend in the vicinity of the fusion point, and are observed randomly as compared with the vicinity of the fusion point. Further, from the viewpoint of making the skin feel better, it is also preferred that the constituent fibers 11 do not contain elastic fibers.

Further, the nonwoven fabric 1A includes a constituent fiber 11 formed such that the hydrophilicity of the small-diameter portion 16 is smaller than the hydrophilicity of the large-diameter portion 17. Therefore, the portion where the hydrophilicity is lowered (the small diameter portion 16) is dispersed on the surface of the nonwoven fabric 1A, so that the liquid remaining on the surface of the nonwoven fabric 1A is less, the dryness of the touch is improved, and the distance between the fibers is widened by the small diameter portion 16. The liquid permeability is improved.

Further, the nonwoven fabric 1A is a non-woven fabric of a concavo-convex structure, and is formed such that the fiber density of the side portion 13c is smaller than the fiber density of the top portion 13a and the fiber density of the bottom portion 13b. Therefore, the distance between the fibers in the side portion 13c is wider than the distance between the fibers in the top portion 13a and the bottom portion 13b, so that the air permeability and the liquid permeability of the nonwoven fabric 1A are improved as a whole. Further by The fiber density of the side portion 13c is minimized, and the ridge portion 13 becomes easy to follow the movement of the wearer's skin, and a good skin feel can be achieved.

Further, the nonwoven fabric 1A is a non-woven fabric having a concavo-convex structure, and the number of the change points 18 of the constituent fibers 11 constituting the side portion 13c is larger than the change point of the constituent fibers 11 constituting the top portion 13a. The number of 18s and one of the bottom portions 13b constitute one of the number of change points 18 of the fibers 11. Therefore, a large amount of the portion having a reduced degree of hydrophilicity (the small diameter portion 16) is dispersed in the side portion 13c, so that the liquid residue on the surface is less, the dryness of the touch is further improved, and the distance between the fibers is widened by the small diameter portion 16. Liquid permeability is improved.

Hereinafter, the present invention (second invention) will be described below based on preferred embodiments thereof with reference to the drawings.

Fig. 8 is a perspective view showing a nonwoven fabric 1B (hereinafter also referred to as "nonwoven fabric 1B") according to an embodiment of the present invention (second invention). Fig. 9 is a schematic view showing a cross section of the nonwoven fabric 1B shown in Fig. 8 in the thickness direction. Fig. 10 is an enlarged schematic view showing the constituent fibers 11 of the nonwoven fabric 1B shown in Fig. 8. As shown in Fig. 8, the nonwoven fabric 1B is a non-woven fabric including a plurality of fusion portions 12 (see Fig. 10) formed by thermally fusing the intersections of the constituent fibers 11. In the present embodiment, as shown in FIG. 8, the nonwoven fabric 1B is a non-woven fabric having a concavo-convex structure in which stripe-shaped ridge portions 13 and recessed portions 14 extending in one direction (X direction) are alternately arranged. Specifically, as shown in FIG. 9 , the nonwoven fabric 1B has a plurality of ridge portions 13 in which the cross-sectional shapes of the front and back surfaces a and b are convexly formed above the thickness direction (Z direction), and the adjacent ridges are located. The concave portion 14 between the portions 13, 13 is in contact with each other. The cross-sectional shape of both the front and back sides a and b of the concave strip portion 14 is formed in a concave shape above the thickness direction (Z direction) of the nonwoven fabric. In other words, the cross-sectional shapes of the front and back surfaces a and b of the concave strip portion 14 are both convex toward the lower side in the thickness direction (Z direction) of the nonwoven fabric. Further, the plurality of ridge portions 13 are continuously extended in one direction (X direction) of the nonwoven fabric 1B, and the plurality of the concave strip portions 14 are also formed in a groove shape continuously extending in one direction X of the nonwoven fabric 1B. The ridge portion 13 and the groove portion 14 are parallel to each other and alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

Further, when the nonwoven fabric 1B is viewed in section as shown in Fig. 9, the nonwoven fabric 1B has a top portion 13a, a bottom portion 13b, and a side portion 13c located between the portions 13a, 13b. Also, the top of the ridge portion 13 is formed by the top portion 13a, and the bottom portion of the concave portion 14 is formed by the bottom portion 13b. The top portion 13a, the bottom portion 13b, and the side portion 13c continuously extend in one direction (X direction) of the nonwoven fabric 1B. When the non-woven fabric 1B is viewed in cross section as shown in FIG. 9 in the top region 13a, the bottom region 13b, and the side portion 13c, the thickness 3 of the non-woven fabric 1B in the Z direction is equally divided, and the upper portion in the thickness direction (Z direction) is set as the top portion. In the region 13a, the center portion in the thickness direction (Z direction) is defined as the side portion 13c, and the portion below the thickness direction (Z direction) is defined as the bottom portion 13b. The above distinction was made by the following method.

[Method of Distinguishing Top Area 13a, Bottom Area 13b, and Side Area 13c]

The non-woven fabric 1B was cut in the Y direction using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and a scanning electron microscope (JCM-5100 (trade name) manufactured by JEOL Ltd.) was used. The cut non-woven fabric 1B is enlarged until the portion to be measured sufficiently enters the field of view to be measured (10 to 100 times), and the thickness of the non-woven fabric 1B in the Z direction is equally divided into three, and the upper portion in the thickness direction (Z direction) is set. In the top region 13a, the center portion in the thickness direction (Z direction) is defined as the side portion 13c, and the portion below the thickness direction (Z direction) is defined as the bottom portion 13b.

In the case of analysis from a commercially available diaper or the like, a cold spray is sprayed on the diaper or the like to be cured, and the hot-melt adhesive is cured. Then, each material was peeled off carefully and carefully, and the non-woven fabric to be a target was obtained, and the cutting and measurement were performed as described above.

The nonwoven fabric 1B is manufactured by performing uneven processing on the fiber sheet 1a by the uneven rolls 401 and 402 as one of the following. One direction (X direction) of the nonwoven fabric 1B is the same as the machine direction (MD, traveling direction) when the nonwoven fabric 1a is formed by the uneven processing of the fiber sheet 1a, and the direction (X direction) of the nonwoven fabric 1B is positive. The direction of intersection (Y direction) is the same direction as the orthogonal direction (CD, roller direction) orthogonal to the above-described machine direction (MD, traveling direction).

The constituent fibers 11 of the nonwoven fabric 1B contain high-stretch fibers. Here, the high-stretch fiber included in the constituent fiber 11 means a fiber having a high elongation at the fiber stage of the raw material and a high elongation at the stage of the nonwoven fabric 1B to be produced. The "high-stretch fiber" is a low-speed fiber, for example, as described in paragraph [0033] of JP-A-2010-168715, in addition to the elastic fiber (elastic body). After melt-spinning to obtain a conjugate fiber, heat treatment and/or crimping treatment is performed without stretching treatment, thereby obtaining a heat-extensible fiber which is changed in length by a crystal to change its crystal state by heating; or a resin such as polypropylene or polyethylene, and a fiber produced by setting the spinning speed to a relatively low condition; or dry-blending polyethylene into a polyethylene-polypropylene copolymer having a low crystallinity or polypropylene. A fiber produced by spinning. Among these fibers, the high-stretch fibers are preferably core-sheath type composite fibers having heat fusion properties. The core-sheath type composite fiber may be a concentric core sheath type, may be an eccentric core sheath type, may be a side-by-side type or a profiled type, and is preferably a concentric core sheath type. The fineness of the high-stretch fiber is preferably 1.0 dtex or more, more preferably 2.0 dtex or more, in terms of a raw material stage, from the viewpoint of producing a good non-woven fabric such as softness and skin feel, and the like. It is preferably 10.0 dtex or less, more preferably 8.0 dtex or less, and specifically preferably 1.0 dtex or more and 10.0 dtex or less, more preferably 2.0 dtex or more and 8.0 dtex or less.

The constituent fibers 11 of the nonwoven fabric 1B may be composed of other fibers in addition to the high-stretch fibers, and are preferably composed of only non-elastic fibers, and more preferably composed only of high-stretch fibers. Examples of the other fiber include a non-heat-extensible core-sheath type heat-fusible composite fiber including two kinds of components having different melting points and a heat-fusible fiber (for example, cotton or pulp). Natural fiber, enamel or acetate fiber, etc.). In the case where the non-woven fabric 1B0 is composed of other fibers in addition to the high-stretch fibers, the ratio of the high-stretch fibers in the nonwoven fabric 1B0 is preferably 50% by mass or more, more preferably 80% by mass or more, and further preferably It is 100% by mass or less, more preferably 100% by mass or less, and specifically, preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass. The mass% or more and 100% by mass or less.

The conjugate fiber which is not subjected to the elongation treatment or the weak elongation treatment in the raw material stage as the heat-expandable fiber as an example of the high-stretch fiber has, for example, a first resin component constituting the core portion and a polyethylene resin constituting the sheath portion. In the second resin component, the first resin component has a higher melting point than the second resin component. The first resin component is a component that exhibits thermal elongation of the fiber, and the second resin component is a component that exhibits heat fusion properties. The melting point of the first resin component and the second resin component was measured by using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Co., Ltd.), and the fiber sample (sample weight: 2 mg) which was finely cut at a temperature increase rate of 10 ° C / Min was subjected to thermal analysis to determine the melting peak temperature of each resin and defined as its melting peak temperature. When the melting point of the second resin component cannot be clearly measured by the method, the resin is defined as "a resin having no melting point". In this case, the temperature at which the molecules of the second resin component start to flow is a temperature at which the second resin component is fused to the extent that the fusion point strength of the fiber can be measured, and the softening point is used instead of the melting point.

The second resin component constituting the sheath portion contains a polyethylene resin as described above. Examples of the polyethylene resin include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). More preferably, it is a high density polyethylene having a density of 0.935 g/cm ³ or more and 0.965 g/cm ³ or less. The second resin component constituting the sheath portion is preferably a polyethylene resin alone, but may be blended with other resins. Examples of the other resin to be blended include a polypropylene resin, an ethylene-vinyl acetate copolymer (EVA), and an ethylene-vinyl alcohol copolymer (EVOH). However, the second resin component constituting the sheath portion is preferably a polyethylene resin in an amount of 50% by mass or more, particularly preferably 70% by mass or more and 100% by mass or less based on the resin component of the sheath portion. Further, the polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, more preferably 11.5 nm or more and 18 nm or less.

As the first resin component constituting the core portion, a resin component having a higher melting point than the polyethylene resin as the constituent resin of the sheath portion can be used without particular limitation. Examples of the resin component constituting the core portion include polyolefin resins (excluding polyethylene resins) such as polypropylene (PP), and polycondensation. A polyester resin such as ethylene terephthalate (PET) or polybutylene terephthalate (PBT). Further, a polyamine polymer or a resin component may be used as a copolymer of two or more kinds. A plurality of resins may be blended and used, and in this case, the melting point of the core is set to the melting point of the resin having the highest melting point. In terms of the ease of producing the nonwoven fabric, it is preferable that the difference between the melting point of the first resin component constituting the core portion and the melting point of the second resin component constituting the sheath portion (the former - the latter) is 20 ° C or higher, and more preferably Below 150 °C.

The preferred orientation index of the first resin component in the thermally extensible fiber as an example of the high-stretch fiber is naturally different depending on the resin to be used, for example, when the first resin component is a polypropylene resin, the alignment The index is preferably 60% or less, more preferably 40% or less, and still more preferably 25% or less. When the first resin component is a polyester, the orientation index is preferably 25% or less, more preferably 20% or less, still more preferably 10% or less. On the other hand, the second resin component preferably has an alignment index of 5% or more, more preferably 15% or more, still more preferably 30% or more. The alignment index is an index of the degree of alignment of the polymer chains constituting the resin of the fiber.

The alignment index of the first resin component and the second resin component can be determined by the method described in paragraphs [0027] to [0029] of JP-A-2010-168715. Further, a method of achieving the above-described alignment index for each of the resin components in the thermally extensible fiber is described in paragraphs [0033] to [0036] of JP-A-2010-168715.

Further, the elongation of the high-stretch fiber is preferably 100% or more, more preferably 200% or more, further preferably 250% or more, and preferably 800% or less, more preferably 500% or less, in the raw material stage, and further It is preferably 400% or less, and specifically preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, further preferably 250% or more and 400% or less. By using a high-stretch fiber having an elongation of the range, the fiber is smoothly stretched in the stretching device, and the following point 18 from the small-diameter portion 16 to the large-diameter portion 17 is adjacent to the fusion portion 12 The skin feels good.

The elongation of high-stretch fiber is based on JIS L-1015 to measure the ambient temperature and humidity of 20±2. The measurement under the conditions of °C, 65±2% RH, a clamping interval of a tensile tester of 20 mm, and a tensile speed of 20 mm/min was used as a reference. Further, when the self-manufactured non-woven fabric is used to collect the fibers and the elongation is measured, and the nip interval cannot be set to 20 mm, that is, when the fiber length to be measured is less than 20 mm, the nip interval is set to 10 mm or The measurement was carried out at 5 mm.

The ratio of the first resin component to the second resin component in the high-stretch fiber (mass ratio, the former: the latter) is preferably 10:90 to 90:10, particularly 20:80 to 80:20 at the raw material stage, and further It is 50:50~70:30. The fiber length of the high-stretch fiber can be used according to the manufacturing method of the nonwoven fabric. When the nonwoven fabric is produced by the carding method as described below, for example, the fiber length is preferably about 30 to 70 mm.

The fiber diameter of the high-stretch fiber can be appropriately selected depending on the specific use of the nonwoven fabric in the raw material stage. When a non-woven fabric is used as a constituent member of an absorbent article such as a front sheet of an absorbent article, it is preferably used in an amount of 10 μm or more, particularly preferably 15 μm or more, and preferably 35 μm or less, particularly preferably When 30 μm or less is used, specifically, it is preferably 10 μm or more and 35 μm or less, particularly 15 μm or more and 30 μm or less. The above fiber diameter was measured by the following method.

[Determination of fiber diameter of fibers]

As the fiber diameter of the fiber, the fiber diameter (μm) was measured by observing the cross section of the fiber by 200 to 800 times using a scanning electron microscope (JCM-5100, manufactured by JEOL Ltd.). The cross section of the fiber was obtained by cutting a fiber using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). The fiber diameter at the time of five approximate circular shapes was measured for the extracted one fiber, and the average value of the five values measured separately was set as the diameter of the fiber.

In the case of using the heat-extensible fiber as an example of the high-stretch fiber in the raw material stage, in addition to the above-mentioned heat-extensible fiber, Japanese Patent No. 4131852, Japanese Patent Laid-Open Publication No. 2005-350836, and Japanese Patent No. Special opening 2007-303035 The fibers described in the Japanese Patent Laid-Open Publication No. 2007-204899, the Japanese Patent Publication No. 2007-204901, and the Japanese Patent Publication No. 2007-204902.

As shown in FIG. 10, the non-woven fabric of the present invention (second invention) focuses on one of the constituent fibers 11 of the nonwoven fabric 1B, and the constituent fibers 11 have between the adjacent fusion portions 12 and 12. The large diameter portion 17 having a large fiber diameter sandwiched by the small diameter portions 16 and 16 having two small fiber diameters. Specifically, as shown in FIG. 10, one of the constituent fibers 11 of the nonwoven fabric 1B is formed, and the small-diameter portion 16 having a small fiber diameter is self-contained with another constituent fiber with substantially the same fiber diameter. The fusion portion 12 formed by heat fusion at the intersection of 11 is formed to be extended. Further, attention is paid to the one constituent fiber 11 which is formed between the small diameter portions 16 and 16 extending from the adjacent fusion portions 12 and 12, and the fiber diameter is larger than the large diameter portion of the small diameter portion 16. 17 is formed by extending substantially the same fiber diameter. As will be described in detail, the nonwoven fabric 1B has the constituent fibers 11 which are focused on one constituent fiber 11 and have a fusing portion 12 disposed one by one from the adjacent fusing portions 12 and 12 toward the other fusing portion 12. The small diameter portion 16 on the side, the one large diameter portion 17, and the small diameter portion 16 on the other fusion portion 12 side. In addition, as for the nonwoven fabric 1B, as shown in FIG. 10, one of the constituent fibers 11 of the nonwoven fabric 1B is formed, and a plurality of the adjacent constituents 12 and 12 are provided between the adjacent fabrics 1 and 2 (not in the nonwoven fabric 1B). The constituent fibers 11 of the large diameter portion 17 are formed. As will be described in detail, the nonwoven fabric 1B has the constituent fibers 11 which are focused on one constituent fiber 11 and have a fusing portion 12 disposed one by one from the adjacent fusing portions 12 and 12 toward the other fusing portion 12. The small diameter portion 16 on the side, the first large diameter portion 17, the small diameter portion 16, the second large diameter portion 17, and the small diameter portion 16 on the other fusion portion 12 side. By having the small-diameter portion 16 having low rigidity adjacent to the fusion portion 12 for increasing the rigidity of the nonwoven fabric 1B as described above, the softness of the nonwoven fabric 1B is improved, and the skin feel is good. In addition, the larger the large diameter portion 17, in other words, the small diameter portion 16 having the low rigidity of the constituent fibers 11, the more the softness of the nonwoven fabric 1B is further improved, and the skin feel is further improved. Regarding the non-woven fabric 1B, from the viewpoint of improving the feeling of the skin and the strength of the non-woven fabric, attention is paid to one constituent fiber 11 to the adjacent fusion portion. 12 and 12 preferably have one or more large diameter portions 17 and further preferably have one or more, and preferably have five or less, and more preferably have three or less. Specifically, It is preferable to have one or more and five or less, and it is more preferable to have one or more and three or less.

The small-diameter portion 16 of the fiber diameter (L ₁₆₎ with respect to the large diameter portion 17 of the fiber diameter (L ₁₇₎ of the ratio (L ₁₆ / L ₁₇₎ is preferably 0.5 or more, and further preferably 0.55 or more, and more It is preferably 0.8 or less, more preferably 0.7 or less, and specifically preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less. Specifically, the fiber diameter (diameter L ₁₆ ) of the small-diameter portion 16 is preferably 5 μm or more, more preferably 6.5 μm or more, and particularly preferably 7.5, from the viewpoint of improving the feeling of the skin and reducing the strength of the nonwoven fabric. It is preferably not more than μm, more preferably 28 μm or less, further preferably 20 μm or less, and particularly preferably 16 μm or less, and specifically preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more, more preferably 13 μm or more, and particularly preferably 15 μm or more, and preferably 35 μm or less, from the viewpoint of improving the touch of the skin. It is preferably 25 μm or less, and particularly preferably 20 μm or less. Specifically, it is preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and still more preferably 15 μm or more and 20 μm or less.

The fiber diameters (diameters L ₁₆ and L ₁₇ ) of the small diameter portion 16 and the large diameter portion 17 were measured in the same manner as the measurement of the fiber diameter of the above fibers.

In the nonwoven fabric of the present invention (second invention), as shown in FIG. 10, one of the constituent fibers 11 of the nonwoven fabric 1B is focused on the large-diameter portion from the small-diameter portion 16 adjacent to the fusion portion 12 to the large-diameter portion. The change point 18 of 17 is disposed within a range from the fusion portion 12 to one third of the interval T between the adjacent fusion portions 12 and 12. Here, the change point 18 of the nonwoven fabric of the present invention (second invention) does not include the small diameter portion 16 extending from the smaller fiber diameter continuously to the fiber diameter larger than the small diameter portion 16 The large diameter section 17 gradually changes The portion or the portion that continuously changes to the large diameter portion 17 through a plurality of stages means a portion where the fiber diameter is extremely changed. In the case where the one constituent fiber 11 is a core-sheath type composite fiber, the change point 18 of the nonwoven fabric of the present invention (second invention) does not include the first resin component and the constituent sheath constituting the core portion. The state in which the second resin component is separated from each other and the fiber diameter is changed means a portion where the fiber diameter is always changed by stretching.

Further, the change point 18 is disposed in a range from the fusion portion 12 to the 1/3 of the interval T between the adjacent fusion portions 12 and 12, and means that the constituent fibers 11 of the nonwoven fabric 1B are randomly extracted and used. JCM-5100 (trade name) manufactured by JEOL Ltd., a scanning electron microscope, in which the constituent fibers 11 can be observed as shown in Fig. 10, and the adjacent fusion portions 12 and 12 of the fibers 11 are observed. (100 times to 300 times) to zoom in. Then, the distance T between the centers of the adjacent fusion portions 12 and 12 is divided into three equal parts, and is divided into a region AT on the side of the fusion portion 12, a region BT on the side of the other fusion portion 12, and a central region CT. Then, the change point 18 is placed in the above-described area AT or the above-described area BT. Further, the change point 18 is disposed in the non-woven fabric 1B in a range from the fusion portion 12 to the 1/3 of the interval T between the adjacent fusion portions 12 and 12, and means that 20 non-woven fabrics 1B are randomly selected. When the fibers 11 are formed, the constituent fibers 11 having the change points 18 in the region AT or the region BT have at least one nonwoven fabric in the 20 constituent fibers 11. Specifically, from the viewpoint of improving the feeling of touch, it is preferably one or more, more preferably five or more, and still more preferably 10 or more.

As described below, the non-woven fabric 1B of the present embodiment is extended not only by the side portion 13c but also the top portion 13a at the top of the ridge portion 13 and the bottom portion 13b at the bottom of the concave portion 14, as compared with the front portion The raw material is not woven, and the fiber density of the non-woven fabric is reduced. Thereby, the liquid permeability and air permeability of the nonwoven fabric 1B as a whole are improved. In the top portion 13a, the bottom portion 13b, and the side portion 13c, the side portion 13c is particularly easy to be stretched, and the fiber density is easily lowered. In the side portion 13c, the liquid permeability and the air permeability are particularly improved.

The non-woven fabric 1B of the present embodiment is formed such that the fiber density of the side portion 13c is smaller than the fiber density of the top portion 13a which is the top of the ridge portion 13, and the fiber density of the bottom portion 13b which is the bottom of the concave portion 14. Here, the fiber density means the fiber mass per unit volume of the nonwoven fabric 1B. The higher fiber density means that the amount of fibers per unit volume of the nonwoven fabric 1B is large, and the distance between the fibers is small. The lower fiber density means that the amount of fibers per unit volume of the nonwoven fabric 1B is small and the distance between the fibers is large. Further, the capillary strength is increased in the portion where the fiber density is high, and the capillary force is lowered in the portion where the fiber density is low.

When the nonwoven fabric 1B is viewed in section as shown in Fig. 9, the nonwoven fabric 1B is such that the fiber density of the side portion 13c between the top of the ridge portion 13 (the top portion 13a) and the bottom portion (the bottom portion 13b) of the concave portion 14 is minimized. The way it is formed. Therefore, in the side portion 13c, the amount of fibers per unit volume of the nonwoven fabric 1B is minimized, the distance between fibers is maximized, and the air permeability of the nonwoven fabric 1B as a whole is improved and the liquid permeability is also improved. Further, by forming the fiber density of the side portion 13c to a minimum, the ridge portion 13 easily follows the movement of the wearer's skin, and a good skin feel can be achieved. In order to impart such a fiber density to the side portion 13c, the nonwoven fabric 1B may be produced in accordance with the following production method.

Lateral zones fiber density 13c of (D ₁₅₎ with respect to the fiber density (D ₁₃₎ at the top region 13a of the rate, or relative to the fiber density (D ₁₄₎ the bottom of the region 13b of the ratio _{(D 15 / D 13, D} 15 /D ₁₄ ) is preferably 0.15 or more, more preferably 0.2 or more, and is preferably 0.9 or less, further preferably 0.8 or less, specifically, preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more. And 0.8 or less. Further, regarding the specific value of the fiber density of the nonwoven fabric 1B, the fiber density (D ₁₃ ) of the top portion 13a is preferably 80 pieces/mm ² or more, further preferably 90 pieces/mm ² or more, and preferably 200 pieces / Mm ² or less is more preferably 180 pieces/mm ² or less, and specifically, preferably 80 pieces/mm ² or more and 200 pieces/mm ² or less, and more preferably 90 pieces/mm ² or more and 180 pieces / Below mm ² . Further, the fiber density (D ₁₄ ) of the bottom portion 13b is preferably 80 pieces/mm ² or more, further preferably 90 pieces/mm ² or more, and more preferably 200 pieces/mm ² or less, and further preferably 180 pieces. / mm ² or less, specifically, is preferably 80 / mm ² or more and 200 / mm ² or less, further preferably 90 / mm ² or more and 180 / mm ² or less. Further, the fiber density (D ₁₅ ) of the side portion 13c is preferably 30 pieces/mm ² or more, more preferably 40 pieces/mm ² or more, and further preferably 80 pieces/mm ² or less, and further preferably 70 pieces. The root/mm ² or less is specifically 30 pieces/mm ² or more and 80 pieces/mm ² or less, and more preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less. The fiber density of the top portion 13a is measured at a position near the apex of the ridge portion 13. The fiber density of the bottom portion 13b is measured at a position near the bottom point of the concave portion 14. The method for measuring the fiber density is as follows.

[Method for Measuring Fiber Density of Top Zone 13a, Bottom Zone 13b or Side Zone 13c]

The nonwoven fabric was cut with a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and the fiber density of the top region 13a was measured by using a scanning electron microscope, and the thickness of the cut surface of the nonwoven fabric was 3 in the Z direction. The upper part of the time division, that is, the vicinity of the apex of the ridge portion 13 is magnified and observed (adjusted to measure the magnification of the fiber profile of 30 to 60 fibers; 150 to 500 times), by the above-mentioned area (0.5 mm ² ) Cut the surface and count the number of sections of the cut fiber. Then, the number of sections of the fiber per 1 mm ^{2 was} converted into the fiber density of the top portion 13a. The measurement was carried out at three locations, and averaged and set as the fiber density of the sample. In the same manner, the fiber density of the bottom portion 13b is determined by measuring the vicinity of the bottom point of the concave portion 14 when the thickness of the cut surface of the nonwoven fabric is equally divided in the Z direction by three. Similarly, the fiber density of the side portion 13c is determined by measuring the center portion when the thickness of the cut surface of the nonwoven fabric is equally divided in the Z direction by three. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

Further, in the nonwoven fabric 1B of the present embodiment, the number of fibers having the change point 18 among the constituent fibers constituting the side portion 13c is larger than the number of fibers having the change point 18 among the constituent fibers of the top portion 13a and the bottom portion 13b. The way is formed. Thereby, the top region 13a becomes easy to follow the movement of the wearer's skin, and a good skin feel can be achieved. The ratio of the number of fibers (N ₁₅ ) having the change point 18 in the constituent fibers constituting the side portion 13c to the number of fibers (N ₁₃ ) having the change point 18 among the constituent fibers constituting the top portion 13a, or relative to the constitution The ratio (N ₁₅ /N ₁₃ , N ₁₅ /N ₁₄ ) of the number of fibers (N ₁₄ ) having the change point 18 in the constituent fibers of the bottom portion 13b is preferably 2 or more, more preferably 5 or more, and is preferably. It is 20 or less, more preferably 20 or less, and specifically, it is preferably 2 or more and 20 or less, and more preferably 5 or more and 20 or less. Further, regarding the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1B, the number of fibers (N ₁₃ ) having the change point 18 among the constituent fibers constituting the top portion 13a is preferably one or more, and more preferably 5 or more. The roots are preferably 15 or less, more preferably 15 or less, and specifically preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less. Further, the number of fibers (N ₁₄ ) having a change point 18 in the constituent fibers constituting the bottom portion 13b is preferably one or more, more preferably five or more, and preferably 15 or less, and more preferably 15 or less. Specifically, the roots are preferably one or more and 15 or less, and more preferably five or more and 15 or less. Further, the number of fibers (N ₁₅ ) having the change point 18 in the constituent fibers constituting the side portion 13c is preferably 5 or more, more preferably 10 or more, and still preferably 20 or less, and further preferably 20 or less, specifically, it is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method of measuring the number of fibers having the change point 18 is as follows.

[Method for Measuring the Number of Fibers Having Change Point 18 among the constituent fibers of the top portion 13a, the bottom portion 13b, or the side portion 13c]

The number of fibers having the change point 18 in the constituent fibers 11 constituting the top portion 13a is enlarged by the scanning electron microscope, and the vicinity of the apex portion of the ridge portion 13 when the thickness of the nonwoven fabric is equally divided in the Z direction is enlarged. Observe (adjusted to measure the magnification of the fiber profile of 30 to 60 fibers; 50 to 500 times), randomly select 20 constituent fibers 11 constituting the top portion 13a, and count the number of fibers having 20 change points 18 in the constituent fibers 11. . When there is one or more change points 18 between the fusion portions, the number of fibers having the change point 18 is set to be one, and when there are a plurality of fibers, the number is also one. Set it to form the top area The number of fibers having a change point 18 among the constituent fibers of 13a. The measurement was carried out at three locations, and the average was made into the number of fibers having the change point 18 among the constituent fibers constituting the top portion 13a of the sample. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom portion 13b is measured in the vicinity of the bottom point of the concave portion 14 when the thickness of the nonwoven fabric is equally divided in the Z direction by three. Out. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the side portion 13c is determined by measuring the center portion when the thickness of the nonwoven fabric is equally divided in the Z direction by three. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

The nonwoven fabric 1B of the present embodiment can be used, for example, for a disposable sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin opposing surface side, and a disposable body interposed between the two sheets. Absorbent articles such as diapers or sanitary napkins. In particular, the front sheet of the constituent member of the absorbent article may be formed of the nonwoven fabric 1B, or the liquid permeable sublayer disposed between the front sheet and the absorbent body may be formed of the nonwoven fabric 1B. When the front sheet is formed of the nonwoven fabric 1B, since the nonwoven fabric 1B is a non-woven fabric having a concavo-convex structure, the contact area ratio with the skin is lowered, and friction is less likely to occur. In addition, when the nonwoven fabric 1B is formed of the nonwoven fabric 1B, the nonwoven fabric 1B is a non-woven fabric having a concavo-convex structure, so that the compression resistance is improved, the cushioning feeling is improved, and the backwash of the body fluid can be prevented.

Regarding the thickness of the nonwoven fabric 1B, the overall thickness of the nonwoven fabric 1B when viewed from the side is the sheet thickness T _S , and the partial thickness of the nonwoven fabric 1B which is bent by the unevenness is defined as the layer thickness T _L . The sheet thickness T _{S may} be appropriately adjusted according to the use, and is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 7 mm or less when used as a front sheet or a secondary layer of an absorbent article. More preferably, it is 5 mm or less, and specifically, it is preferably 0.5 mm or more and 7 mm or less, more preferably 1 mm or more and 5 mm or less. By setting it as this range, the body fluid absorption rate at the time of use is accelerated, and the liquid return of the self-absorber can be suppressed, and the moderate cushioning property can be implement|achieved.

The layer thickness T _L may be different in each portion in the nonwoven fabric 1B, and may be appropriately adjusted according to the use. When used as a front sheet or a sub-layer of an absorbent article, the layer thickness T _{L1 of the} top portion 13a is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, specifically, it is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L2 of the} bottom portion 13b is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, and specifically, preferably 0.1 mm or more and 3.0 mm. Hereinafter, it is more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L3 of the} side portion 13c is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 3.0 mm or less, more preferably 2.0 mm or less, and specifically, preferably 0.1 mm or more and 3.0. Below mm, more preferably 0.2 mm or more and 2.0 mm or less. By setting it as this range, the body fluid absorption rate at the time of use is accelerated, and the liquid return of the self-absorber can be suppressed, and the moderate cushioning property can be implement|achieved.

The sheet thickness T _S and the layer thickness T _L were measured by the following methods.

The measurement method of the sheet thickness T _S was carried out using a thickness measuring device while applying a load of 0.05 kPa to the nonwoven fabric 1B. The thickness gauge is a laser displacement meter manufactured by Omron. In the thickness measurement system, 10 points were measured, and the average value of these was calculated and made into thickness.

The layer thickness T _L was measured by a digital microscope VHX-900 manufactured by KEYENCE, which magnified the cross section of the sheet by about 20 times, thereby measuring the thickness of each layer.

When the non-woven fabric 1B is viewed from above, the distance between the adjacent top regions 13a in the Y direction may be appropriately adjusted according to the use, and when used as a front sheet or a sub-layer of an absorbent article, it is preferably 1 mm or more. It is preferably 1.5 mm or more, and is preferably 15 mm or less, more preferably 10 mm or less, and specifically preferably 1 mm or more and 15 mm or less, more preferably 1.5 mm or more and 10 mm or less.

Further, the basis weight of the nonwoven fabric 1B also depends on the specific use of the nonwoven fabric 1B, and in the case of being used as the front sheet or the secondary layer of the absorbent article, it is preferably 15 g/m ² or more based on the average value of the entire sheet. More preferably, it is 20 g/m ² or more, and is preferably 50 g/m ² or less, more preferably 40 g/m ² or less, and specifically, preferably 15 g/m ² or more and 50 g/m ² or less, more preferably It is 20 g/m ² or more and 40 g/m ² or less.

Further, a small amount of a fiber coloring agent, an antistatic property agent, a lubricant, a hydrophilic agent or the like may be applied to the surface of the constituent fiber 11 of the nonwoven fabric 1B at the raw material stage.

As a method of attaching the fiber treating agent to the surface constituting the fiber 11, various known methods can be employed without particular limitation. For example, spray coating, application by a slit coater, application by roll transfer, immersion in a fiber treatment agent, etc. are mentioned. These treatments may be carried out on the fibers before the fiber webization, or the fibers may be subjected to fiber meshing by various methods. However, it must be processed before the hot air blowing process described below. The fiber to which the fiber treatment agent is adhered on the surface is dried, for example, by a hot air blow dryer at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C or lower).

The non-woven fabric of the present invention (second invention) is produced by a method for producing a non-woven fabric having a step of melting a portion of the constituent fibers of the web including the high-stretch fibers by heat fusion through the fusion portion. a fiber sheet; and an extending step of extending the fiber sheet in one direction. In one embodiment of the method for producing a nonwoven fabric according to the present invention (second invention), a preferred manufacturing method of the nonwoven fabric 1B will be described as an example, and will be described with reference to FIG. In Fig. 11, a preferred manufacturing apparatus 100B used in the manufacturing method of the nonwoven fabric 1B is schematically shown. The manufacturing apparatus 100B can be preferably used for the manufacturer of the hot air non-woven fabric. The manufacturing apparatus 100B is provided with the web forming part 200, the hot air processing part 300, and the extension part 400 in order from the upstream side of the manufacturing process to the downstream side.

As shown in FIG. 11, the web forming part 200 is provided with the web forming apparatus 201. As the web forming device 201, a carding machine can be used. As the card, the same as the card generally used in the technical field of absorbent articles can be used without particular limitation. Depending on the specific use of the nonwoven fabric 1B, other web manufacturing equipment, such as an air spinning device, may be used instead of the carding machine.

As shown in FIG. 11 , the hot air treatment unit 300 includes a filter cover 301 . In the filter cover 301, hot air can be blown by hot air. Further, the hot air treatment unit 300 includes a belt 302 having a ring shape including a permeable mesh. A conveyor belt 302 surrounds the filter housing 301. The conveyor belt 302 is formed of a resin such as polyethylene terephthalate or a metal.

The temperature of the hot air blown into the filter 301 and the heat treatment time are preferably adjusted so that the intersection of the high-stretch fibers contained in the constituent fibers 11 of the fiber web 10 is thermally fused. Specifically, the temperature of the hot air is preferably adjusted to a temperature of 0 ° C to 30 ° C higher than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 10 . The heat treatment time is preferably adjusted to 1 second to 5 seconds depending on the temperature of the hot air. Further, from the viewpoint of promoting further entanglement of the constituent fibers 11 with each other, the wind speed of the hot air is preferably about 0.3 m/sec to 1.5 m/sec. Further, the conveying speed is preferably about 5 m/min to 100 m/min.

As shown in FIGS. 11 and 12, the extending portion 400 is provided with a pair of uneven rollers 401 and 402 that can mesh with each other. The pair of uneven rollers 401 and 402 are formed to be heatable, and are formed by alternately arranging the large-diameter convex portions 403 and 404 and the small-diameter concave portions (not shown) in the roller axis direction. The embossing rolls 401 and 402 can be heated or not, and the high-stretch fibers included in the constituent fibers 11 of the fiber sheet 1a described below can be easily heated in the case of heating the embossing rolls 401 and 402. The temperature is preferably set to be greater than or equal to the melting point of the resin having the highest glass transition point in the high elongation fiber and the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, it is higher than the temperature at which the glass transition point of the fiber is 10 ° C or higher and 10 ° C lower than the melting point, and further preferably higher than the temperature of the glass transition point of the fiber by 20 ° C or higher and lower than the melting point by 20 ° C. . For example, when the fiber is used as a core/sheath structure fiber, the glass transfer point is 67 ° C, the melting point is 258 ° C, the PET (core) / glass transition point is -20 ° C, and the melting point is 135 ° C PE (sheath). In the case of heating, it is preferably heated to 67 ° C or more and 135 ° C or less, more preferably to 77 ° C or more and 125 ° C or less, and further preferably heated to 87 ° C or more and 115 ° C or less.

Further, as shown in FIG. 13, in the manufacturing apparatus 100B, in the roll axis direction of the uneven roller 401 The interval (pitch) between the adjacent large-diameter convex portions 403 and 403 and the interval (pitch) between the large-diameter convex portions 404 and 404 adjacent to each other in the roll axis direction of the uneven roller 402 are the same interval (pitch) w) The high-stretch fibers included in the constituent fibers 11 of the fiber sheet 1a are smoothly stretched in the stretching device, and the change from the small-diameter portion to the large-diameter portion is adjacent to the fusion portion to make the skin feel From the viewpoint of being good, the interval (pitch) w is preferably 1 mm or more, more preferably 1.5 mm or more, and is preferably 10 mm or less, particularly preferably 8 mm or less, and specifically, preferably 1 mm or more and 10 mm. Hereinafter, it is particularly preferably 1.5 mm or more and 8 mm or less. From the same viewpoint, as shown in FIG. 13, the pressing amount t of the pair of uneven rollers 401, 402 (the apex of the large-diameter convex portion 403 adjacent to the roller axis direction and the apex of the large-diameter convex portion 404) The interval) is preferably 1 mm or more, more preferably 1.2 mm or more, and is preferably 3 mm or less, more preferably 2.5 mm or less, and specifically, preferably 1 mm or more and 3 mm or less, particularly preferably 1.2 mm or more and 2.5. Below mm. Further, from the same viewpoint, the mechanical stretching ratio is preferably 1.5 times or more, more preferably 1.7 times or more, and is preferably 3.0 times or less, particularly preferably 2.8 times or less, and specifically, preferably 1.5 times. The above is 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

A method of manufacturing the nonwoven fabric 1B using the manufacturing apparatus 100B having the above configuration will be described.

First, as shown in Fig. 11, in the web forming portion 200, a short fiber-like constituent fiber 11 having a high-stretch fiber is used as a raw material, and a web 10 is formed by using the web forming device 201 as a card (fiber) Net formation step). The fiber web 10 manufactured by the web forming apparatus 201 is in a state in which the constituent fibers 11 are loosely entangled with each other, and the shape retaining property as a sheet has not yet been obtained.

Then, as shown in FIG. 11, the intersection of the constituent fibers 11 of the fiber web 10 including the high-stretch fibers is thermally fused via the fusion portion 12 to form the fiber sheet 1a (fusion step). Specifically, the fiber web 10 is conveyed to the conveyor belt 302, and the hot air is blown by hot air while the hot air processing unit 300 passes through the filter 301. If hot air is blown in this way, Then, the fibers 11 of the fiber web 10 are further entangled with each other, and the intersection of the fibers to be entangled is thermally fused (see Fig. 14 (a)) to produce a fiber sheet 1a having a sheet shape retaining property.

Then, as shown in Fig. 11, the fused fiber web 1a is extended in one direction (extension step). Specifically, the fused fibrous web 1a having the shape retaining property as a sheet is conveyed between the pair of embossing rolls 401 and 402, and as shown in FIGS. 14(a) to 14(c), the web is made. 1a is extended, and a large-diameter portion 17 having a large fiber diameter sandwiched by two small-diameter portions 16 and 16 having a small fiber diameter is formed in one of the constituent fibers 11 between the adjacent fusion portions 12 and 12. The change point 18 from the small diameter portion 16 to the large diameter portion 17 is formed in a range from the fusion portion 12 to a distance 1/3 between the fusion portions 12 and 12 adjacent thereto. As will be described in detail, the fiber sheet 1a which is thermally fused at the intersection of the constituent fibers 11 via the fusion portion 12 is transferred between the pair of embossing rolls 401 and 402 as shown in Fig. 14(a) to form the web 1a. It extends in an orthogonal direction (CD, roller direction) orthogonal to the machine direction (MD, traveling direction). When the fiber sheet 1a is extended in the orthogonal direction (CD, roll direction), as shown in Fig. 14 (a), the regions where the constituent fibers 12, 12 are adjacent to each other, which are fixed to each other, are fixed to each other. It is actively stretched in the orthogonal direction (CD, roll axis direction). In particular, as shown in Fig. 14 (b), in the vicinity of the respective fused portions 12 where the constituent fibers 11 are fixed to each other, first, partial shrinkage is likely to occur, and one of the adjacent fusion-welded portions 12 and 12 constitutes the fibers 11, Two small diameter portions 16 and 16 are formed at both ends, and a portion sandwiched by the two small diameter portions 16 and 16 is a large diameter portion 17 to form a large diameter portion sandwiched by the two small diameter portions 16 and 16. 17. As described above, in the vicinity of each of the fusion portions 12, partial contraction is likely to occur first. Therefore, the change point 18 from the small diameter portion 16 to the large diameter portion 17 is formed in the fusion portion 12 from the fusion portion 12 to the adjacent portion. 12 is within 1/3 of the interval T of each other.

Further, a part of the constituent fibers 11 between the adjacent ones of the welded portions 12 and 12 is in the orthogonal direction in a state where the stretchable space (elongation space) remains as shown in FIG. 14(c) ( CD, roller direction) is further extended to make the adjacent fusion parts 12, 12 The large diameter portion 17 extends therebetween, and the small diameter portion 16 is formed in the large diameter portion 17.

As described above, according to the manufacturing method of the nonwoven fabric 1B using the manufacturing apparatus 100B, the nonwoven fabric 1B which has the structural fiber 11 shown in FIG. 10 can be manufactured continuously and efficiently. As shown in Fig. 11, the nonwoven fabric 1B to be produced is temporarily taken up and stored in the form of a roll, and then taken out from the roll and used. Alternatively, the processing is performed on the subsequent step production line of the manufacturing apparatus 100B of the nonwoven fabric 1B, thereby continuously producing the target article.

As shown in FIG. 10, the non-woven fabric 1B manufactured as described above is focused on one of the constituent fibers 11 of the constituent fibers 11, and is arranged from the small-diameter portion 16 adjacent to the fusion portion 12 to the change point 18 of the large-diameter portion 17. In the range from the fusion portion 12 to the 1/3 of the distance T between the adjacent fusion portions 12 and 12, it becomes soft and the skin feel is good. In particular, attention is paid to one constituent fiber 11. When a plurality of small diameter portions 16 are formed between adjacent fusion portions 12 and 12, the skin feel is better. From the viewpoint of easily exhibiting such an effect, the constituent fibers 11 preferably contain only high-stretch fibers.

When the elastic fibers are incorporated in the constituent fibers 11, the nonwoven fabric is stretched while being shrunk. Therefore, even when the manufacturing method and the mechanical stretching ratio of the nonwoven fabric 1B are the same, it is difficult to cause a change in the fiber diameter. Therefore, when the elastic fiber is incorporated in the constituent fiber 11, it is difficult to form a portion 18 which is a portion where the fiber diameter is extremely changed, and it is easy to form a portion which gradually changes from the small-diameter portion 16 to the large-diameter portion 17. Due to the incorporation of the elastic fibers, the continuously gradually changing portions thus formed do not necessarily locally extend in the vicinity of the fusion point, and are observed randomly as compared with the vicinity of the fusion point. Further, from the viewpoint of making the skin feel better, it is also preferred that the constituent fibers 11 do not contain elastic fibers.

Further, the nonwoven fabric 1B is a non-woven fabric having a concave-convex structure, and is formed such that the fiber density of the side portion 13c is smaller than the fiber density of the top portion 13a and the fiber density of the bottom portion 13b. Therefore, the distance between the fibers of the side portion 13c is wider than the distance between the fibers of the top portion 13a and the bottom portion 13b, so that the air permeability and the liquid permeability of the entire nonwoven fabric 1B are improved. Further by The fiber density of the side portion 13c is minimized, and the ridge portion 13 becomes easy to follow the movement of the wearer's skin, and a good skin feel can be achieved.

Further, the nonwoven fabric 1B is a non-woven fabric having a concavo-convex structure, and the number of the change points 18 of the constituent fibers 11 constituting the side portion 13c is larger than the change point of the constituent fibers 11 constituting the top portion 13a. The number of 18s and one of the bottom portions 13b constitute one of the number of change points 18 of the fibers 11. Therefore, the rib portion 13 easily follows the movement of the wearer's skin and achieves a good skin feel.

The non-woven fabric of the present invention (first invention) is not limited to the nonwoven fabric 1A of the above-described embodiment, and can be appropriately modified.

Further, the method for producing the nonwoven fabric of the present invention (first invention) is not limited to the above-described production method, and can be appropriately changed.

For example, as shown in FIG. 1, the nonwoven fabric 1A is a non-woven fabric having a concave-convex structure in which stripe-shaped ridge portions 13 and concave strip portions 14 extending in one direction (X direction) are alternately arranged, but the convex portions may be The non-woven fabric of the three-dimensional concavo-convex structure in which the X-direction and the Y-direction are intermittently arranged at a predetermined interval in a zigzag-like arrangement pattern. Moreover, from the viewpoint of improving the shape retention property of the uneven structure, the non-woven fabric of the uneven structure may be placed on the other nonwoven fabric and bonded, or the embossing process may be performed on the nonwoven fabric of the uneven structure. Further, the nonwoven fabric 1A may be a non-woven fabric having a flat structure without being uneven.

Further, according to the manufacturing method of the nonwoven fabric 1A using the above-described manufacturing apparatus 100, the web 1a is extended in the orthogonal direction (CD, roll direction) orthogonal to the machine direction (MD, traveling direction), but it may be further The machine direction (MD, direction of travel) extends. When extending in the machine direction (MD, traveling direction) as described above, the convex portions provided in the pair of the uneven rollers 401 and 402 may be arranged on the circumferential surface in the direction of the rotation axis.

Further, according to the manufacturing method of the nonwoven fabric 1A using the above-described manufacturing apparatus 100, fusion between the web forming step using the web forming portion 200 and the fusing step using the hot air treating portion 300, or the fusion using the hot air treating portion 300 may be employed. Step and extension of using extension 400 A coating step using a fiber treatment agent coating portion is provided between the stretching steps. This coating step may be performed before the extension step of using the extension portion 400.

The non-woven fabric of the present invention (second invention) is not limited to the nonwoven fabric 1B of the above-described embodiment, and can be appropriately changed.

Further, the method for producing the nonwoven fabric of the present invention (second invention) is not limited to the above-described production method, and can be appropriately changed.

For example, as shown in FIG. 8, the nonwoven fabric 1B is a non-woven fabric having a concave-convex structure in which stripe-shaped ridge portions 13 and concave strip portions 14 extending in one direction (X direction) are alternately arranged, but the convex portions may be The non-woven fabric of the three-dimensional concavo-convex structure in which the X-direction and the Y-direction are intermittently arranged at a predetermined interval in a zigzag-like arrangement pattern. Moreover, from the viewpoint of improving the shape retention property of the uneven structure, the non-woven fabric of the uneven structure may be placed on the other nonwoven fabric and bonded, or the embossing process may be performed on the nonwoven fabric of the uneven structure. Further, the nonwoven fabric 1B may be a non-woven fabric having a flat structure without being uneven.

Further, according to the manufacturing method of the nonwoven fabric 1B using the above-described manufacturing apparatus 100B, the web 1a is extended in the orthogonal direction (CD, roll direction) orthogonal to the machine direction (MD, traveling direction), but it may be further The machine direction (MD, direction of travel) extends. When extending in the machine direction (MD, traveling direction) as described above, the convex portions provided in the pair of the uneven rollers 401 and 402 may be arranged on the circumferential surface in the direction of the rotation axis.

The omission of the description of the above-described embodiments and the requirements of only one embodiment can be appropriately applied to other embodiments, and the requirements of the respective embodiments can be appropriately replaced with each other between the embodiments.

Regarding the above embodiment, the following non-woven fabrics are further disclosed.

<1> A non-woven fabric comprising a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers, and the constituent fibers comprising high-stretch fibers, focusing on one of the constituent fibers, the constituent fibers being adjacent to each other The above-mentioned fusion parts are mutually There is a large diameter portion having a large fiber diameter sandwiched by two small diameter portions having a small fiber diameter, and the small diameter portion has a hydrophilicity smaller than that of the large diameter portion.

<2> The non-woven fabric according to the above <1>, wherein a difference between the contact angle of the small-diameter portion and the contact angle of the large-diameter portion (the former one is the latter) is 1 degree or more, more preferably 5 degrees or more, and further Preferably, it is 10 degrees or more, and is preferably 25 degrees or less, more preferably 20 degrees or less, still more preferably 15 degrees or less, and specifically, preferably 1 degree or more and 25 degrees or less, and further preferably 5 or less. The degree is not less than 20 degrees, more preferably not less than 10 degrees and not more than 15 degrees.

<3> The nonwoven fabric according to the above <1> or <2>, wherein the contact angle of the small diameter portion is preferably 60 degrees or more, more preferably 70 degrees or more, still more preferably 80 degrees or more, and more preferably It is 100 degrees or less, more preferably 95 degrees or less, further preferably 90 degrees or less, and specifically, preferably 60 degrees or more and 100 degrees or less, more preferably 70 degrees or more and 95 degrees or less, and furthermore Good is 80 degrees or more and 90 degrees or less.

The non-woven fabric according to any one of the above-mentioned items, wherein the contact angle of the large diameter portion is preferably 55 degrees or more, more preferably 60 degrees or more, and still more preferably 65 degrees or more. It is preferably 90 degrees or less, more preferably 85 degrees or less, still more preferably 80 degrees or less, and specifically, preferably 55 degrees or more and 90 degrees or less, and more preferably 60 degrees or more and 85 degrees. Hereinafter, it is more preferably 65 degrees or more and 80 degrees or less.

The non-woven fabric according to any one of the above-mentioned items, wherein the ratio of the fiber diameter (diameter L ₁₆ ) of the small-diameter portion to the fiber diameter (diameter L ₁₇ ) of the large-diameter portion ( L ₁₆ /L ₁₇ ) is preferably 0.5 or more, more preferably 0.55 or more, and is preferably 0.8 or less, more preferably 0.7 or less, and specifically preferably 0.5 or more and 0.8 or less, and further preferably 0.55 or more and 0.7 or less.

The non-woven fabric according to any one of the above-mentioned <1>, wherein the small-diameter portion adjacent to the fusion portion is disposed from the fusion portion to the change point In the range of 1/3 of the distance between the adjacent fused portions, the non-woven fabric is a non-woven fabric having a concave-convex structure in which stripe-like ridge portions and concave portions extending in one direction are alternately arranged, and the non-woven fabric is woven on the top portion. a bottom portion and a side portion between the sides, wherein a top portion of the ridge portion is formed by a top portion, and a bottom portion of the concave portion is formed by a bottom portion, and the constituent fibers constituting the side portion have a change point The ratio of the number of fibers (N ₁₅ ) to the number of fibers having a change point (N ₁₃ ) in the constituent fibers constituting the top portion, or the number of fibers having a change point in the constituent fibers constituting the bottom portion (N ₁₄₎ of the ratio _{(N 15 / N 13, N} 15 / N 14) is preferably 2 or more, and further preferably 5 or more, and preferably 20 or less, and further preferably 20 or less, specifically, It is 2 or more and 20 or less, preferably 5 or more and 20 or less.

The non-woven fabric according to any one of the above-mentioned items, wherein the fiber-treating agent is adhered to the constituent fiber, and the fiber-treating agent contains a component having ductility.

<8> The absorbent article according to the above <7>, wherein the component having the ductility is a component which is easily attached to the surface of the fiber and which is easily spread on the surface of the fiber at a low temperature and is excellent in fluidity at a low temperature.

<9> The non-woven fabric according to <7> or <8> above, wherein the ductile component is polyorganosiloxane.

<10> The non-woven fabric according to the above <9>, wherein the polyorganosiloxane is selected from the group consisting of polydimethyl siloxane, polydimethoxy siloxane, and polydipropyl siloxane.

The non-woven fabric according to any one of the above-mentioned items, wherein the fiber treatment agent further contains a hydrophilic component.

<12> The non-woven fabric according to the above <11>, wherein the hydrophilic component is an amphoteric ionic surfactant or a nonionic surfactant.

<13> The non-woven fabric according to the above <12>, wherein the amphoteric ionic interface The active agent is a betaine-type zwitterionic surfactant, preferably an alkyl (carbon number 1 to 30) betaine, more preferably an alkylbetaine having a carbon number of 16-22 (for example, stearyl).

<14> The non-woven fabric according to the above <12>, wherein the nonionic surfactant is selected from the group consisting of glycerin fatty acid esters, poly(preferably n=2-10) glycerin fatty acid esters, sorbitan fatty acid esters, Polyol fatty acid esters (both preferably fatty acids having a carbon number of 8 to 60), polyoxyalkylene alkyl groups (additional molar number 2 to 20) alkyl groups (carbon number 8 to 22) decylamine, polyoxyalkylene oxide Base (additional molar number 2~20) alkyl (carbon number 8~22) ether, polyoxyalkylene modified polyxanthine, amine modified polyoxylium.

The non-woven fabric according to any one of the above aspects, wherein the fiber treatment agent further contains a hydrophobic component.

<16> The non-woven fabric according to the above <15>, wherein the hydrophobic component is selected from the group consisting of an alkyl phosphate, an anionic surfactant represented by the following formula (1), and the like.

(wherein Z represents a linear or branched alkyl chain having 1 to 12 carbon atoms which may include an ester group, a mercaptoamine group, an amine group, a polyoxyalkylene group, an ether group or a double bond, and R ₁ and R ₂ independently represents a linear or branched alkyl group having 2 to 16 carbon atoms which may include an ester group, a mercaptoamine group, a polyoxyalkylene group, an ether group or a double bond, and X represents -SO ₃ M, -OSO ₃ M or -COOM, M represents H, Na, K, Mg, Ca or ammonium).

<17> The non-woven fabric according to the above <16>, wherein the alkyl phosphate-based carbon chain is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate of 16 to 18.

The non-woven fabric according to any one of the above <1> to <17> wherein The constituent fibers comprise only high elongation fibers.

<19> The non-woven fabric according to the above <18>, wherein the high-stretch fiber is excluding the elastic fiber (elastomer) and stretchable, and is selected from the group consisting of fibers which are melt-spun at a low speed to obtain a composite. After the fiber is subjected to a heat treatment and/or a crimping treatment without stretching treatment, a heat-extensible fiber obtained by heating to change a crystal state of the resin to extend in length, or a resin such as polypropylene or polyethylene is used. A fiber produced by setting a spinning speed to a relatively low condition; or a fiber produced by dry-blending polyethylene and spinning into a polyethylene-polypropylene copolymer having a low crystallinity or polypropylene.

<20> The non-woven fabric according to the above <18> or <19>, wherein the ratio of the high-stretch fibers in the nonwoven fabric is 50% by mass or more, preferably 80% by mass or more, and particularly preferably 100% by mass.

The non-woven fabric according to any one of the above-mentioned items, wherein the high-stretch fiber is not only high in the fiber stage of the raw material but also high in the non-woven stage produced. Fiber of degree.

The non-woven fabric according to any one of the above-mentioned items, wherein the elongation of the high-stretch fiber is preferably 100% or more, more preferably 200% or more, more preferably 200% or more. 250% or more, and preferably 800% or less, more preferably 500% or less, further preferably 400% or less, specifically 100% or more and 800% or less, preferably 200% or more and 500% or less. Further, it is preferably 250% or more and 400% or less.

The non-woven fabric according to any one of the above-mentioned items, wherein the elongation of the high-stretch fiber is 60% or more, preferably 70% or more, more preferably 80% or more in the non-woven stage. And preferably 200% or less, more preferably 150% or less, further preferably 120% or less, and specifically, preferably 60% or more and 200% or less, more preferably 70% or more and 170% or less. Further, it is preferably 80% or more and 150% or less.

<24> The non-woven fabric according to any one of <1> to <23> above, wherein the self-adjacent The change point of the small-diameter portion connected to the fusion portion to the large-diameter portion is within a range of one-third of a distance from the fusion portion to the adjacent portion of the fusion portion.

<25> The non-woven fabric according to any one of the above-mentioned items, wherein the plurality of constituent fibers are disposed, and a plurality of the large-diameter portions are disposed between the adjacent fusion portions.

The non-woven fabric according to any one of the above-mentioned items, wherein the non-woven fabric is a non-woven fabric having a concave-convex structure in which stripe-like ridge portions and concave strip portions extending in one direction are alternately arranged.

<27> The non-woven fabric according to the above <26>, wherein the non-woven fabric has a top portion, a bottom portion, and a side portion between the sides, and a top portion of the ridge portion is formed by a top portion, and a bottom portion of the concave portion Formed by the bottom region, the fiber density of the side regions is less than the fiber density of the top region and the fiber density of the bottom region.

<28> The non-woven fabric according to the above <25> or <27>, wherein the non-woven fabric has a top portion, a bottom portion, and a side portion between the sides, and a top portion of the ridge portion is formed by a top portion, the concave portion The bottom of the strip is formed by the bottom portion, and the number of fibers having a change point in the constituent fibers constituting the side portion is larger than the number of fibers having a change point in the constituent fibers constituting the top portion and the composition constituting the bottom portion The number of fibers in the fiber that have a change point.

<29> The non-woven fabric according to the above <7>, wherein the constituent fiber is formed by attaching the fiber treating agent to the constituent fiber before extending the fiber web including the constituent fiber, and It is obtained by drying the polyethylene resin at a temperature sufficiently low (for example, 120 ° C or lower).

<30> The non-woven fabric according to any one of <1> to <29> above, wherein the above The intersection point of the constituent fibers is a joint, and the joint is the above-mentioned fusion portion.

<31> An absorbent article comprising: a front sheet disposed on the opposite side of the skin; a back sheet disposed on the non-skin opposing surface side; and an absorbent body interposed between the two sheets, and The front sheet is formed of the nonwoven fabric described in any one of the above <1> to <30>.

The non-woven fabric according to any one of the above-mentioned items, wherein the non-woven fabric according to any one of the above-mentioned items, wherein the constituting fibers are formed by a plurality of fused fabrics which are formed by thermally fusing the intersections of the constituent fibers, and the constituent fibers include high-stretch fibers. Focusing on one of the constituent fibers, the constituent fibers have a large diameter portion having a large fiber diameter sandwiched by two small diameter portions having a small fiber diameter between the adjacent fusion portions, and are adjacent to the above-mentioned The point of change of the small-diameter portion of the fusion portion to the large-diameter portion is within a range of one-third of the distance from the fusion portion to the adjacent portion of the fusion portion.

<33> The non-woven fabric according to the above <32>, wherein the fiber diameter (diameter L ₁₆ ) of the small diameter portion is preferably 5 μm or more, more preferably 6.5 μm or more, still more preferably 7.5 μm or more, and preferably It is 28 μm or less, more preferably 20 μm or less, and particularly preferably 16 μm or less. Specifically, it is preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less.

The nonwoven fabric according to any one of the above-mentioned <32>, wherein the fiber diameter (diameter L ₁₇ ) of the large diameter portion is preferably 10 μm or more, more preferably 13 μm or more, and particularly preferably 15 μm. The above is preferably 35 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less, and specifically preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and particularly preferably 15 μm or more. And 20 μm or less.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the change point is formed by changing a fiber diameter by stretching.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the non-woven fabric has one or more, preferably five or more, more preferably 10 or more of the 20 constituent fibers. The constituent fibers of the above change points.

The absorbent article according to the above <6>, wherein the number of fibers (N ₁₃ ) having the change point in the constituent fibers constituting the top region is preferably one or more, and more preferably five or more. It is preferably 15 or less, more preferably 15 or less, and specifically preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less.

<38> The nonwoven fabric according to the above <6> or <37>, wherein the number of fibers (N ₁₄ ) having the above-described change point in the constituent fibers constituting the bottom portion is preferably one or more, and more preferably five. The above is preferably 15 or less, more preferably 15 or less, and specifically preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less.

The non-woven fabric according to any one of the above-mentioned <6>, wherein the number of fibers (N ₁₅ ) having the change point in the constituent fibers constituting the side portion is preferably 5 The roots are more preferably 10 or more, more preferably 20 or less, still more preferably 20 or less, and specifically preferably 5 or more and 20 or less, and more preferably 10 or more. 20 or less.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the constituent fibers include only inelastic fibers.

The non-woven fabric according to any one of the above-mentioned items, wherein the fineness of the high-stretch fiber is preferably 1.0 dtex or more, more preferably 2.0 dtex or more, and preferably 10.0. The dtex or lower is more preferably 8.0 dtex or less, and specifically, preferably 1.0 dtex or more and 10.0 dtex or less, more preferably 2.0 dtex or more and 8.0 dtex or less.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the plurality of constituent fibers are disposed, and a plurality of the large diameter portions are disposed between the adjacent fusion portions.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the one of the constituent fibers is provided, and one or more and five or less of the adjacent fusion portions are preferably provided. It is one or more and three or less of the above-mentioned large diameter portions.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the non-woven fabric is a non-woven fabric having a concavo-convex structure in which stripe-like ridge portions and concave strip portions extending in one direction are alternately arranged.

<45> The non-woven fabric according to the above <44>, wherein the non-woven fabric has a top portion, a bottom portion, and a side portion between the sides, and a top portion of the ridge portion is formed by a top portion, and a bottom portion of the concave portion Formed by the bottom region, the fiber density of the side regions is less than the fiber density of the top region and the fiber density of the bottom region.

The non-woven fabric according to any one of the above-mentioned <32>, wherein the non-woven fabric is a non-woven fabric having a concave-convex structure in which stripe-like ridge portions and concave strip portions extending in one direction are alternately arranged, and The non-woven fabric has a top region, a bottom region and a side portion between the top, the top of the ridge portion is formed by a top portion, and the bottom portion of the concave portion is formed by a bottom portion, and the bottom portion is the fiber density of the wall portion of the (D ₁₅₎ with respect to the fiber density (D ₁₃₎ above the top of the zone, or with respect to fiber density (D ₁₄₎ of said bottom region of the ratio _{(D 15 / D 13, D} 15 / D 14) It is preferably 0.15 or more, more preferably 0.2 or more, and is preferably 0.9 or less, further preferably 0.8 or less, specifically 0.15 or more and 0.9 or less, preferably 0.2 or more and 0.8 or less.

<47> The non-woven fabric according to the above <46>, wherein the fiber density (D ₁₃ ) of the top portion is preferably 80 pieces/mm ² or more, more preferably 90 pieces/mm ² or more, and preferably 200 pieces. /mm ² or less, more preferably 180 / mm ² or less, specifically 80 / mm ² or more and 200 / mm ² or less, preferably 90 / mm ² or more and 180 / mm ² or less .

<48> The non-woven fabric according to the above <46> or <47>, wherein the fiber density (D ₁₄ ) of the bottom portion is preferably 80 pieces/mm ² or more, more preferably 90 pieces/mm ² or more, and It is preferably 200 pieces/mm ² or less, more preferably 180 pieces/mm ² or less, specifically 80 pieces/mm ² or more and 200 pieces/mm ² or less, preferably 90 pieces/mm ² or more and 180 pieces. /mm ² or less.

The non-woven fabric according to any one of the above-mentioned, wherein the fiber density (D ₁₅ ) of the bottom portion is preferably 30 pieces/mm ² or more, and more preferably 40 pieces/mm ^{2 .} The above is preferably 80 pieces/mm ² or less, more preferably 70 pieces/mm ² or less, specifically 30 pieces/mm ² or more and 80 pieces/mm ² or less, preferably 40 pieces/mm ^{2 .} Above 70 pieces/mm ² or less.

The non-woven fabric according to any one of the above-mentioned <45>, wherein the number of fibers having a change point in the constituent fibers constituting the side portion is larger than the number of constituent fibers constituting the top portion. The number of fibers and the number of fibers having a change point in the constituent fibers constituting the bottom portion.

<51> A method for producing a non-woven fabric, comprising: a fusing step of thermally fusing an intersection of constituent fibers of a fiber web including a high-stretch fiber having a fiber treating agent via a fusion portion; and an extending step, After the fusing step, the fused fiber web is extended in one direction; and in the extending step, the fiber web is extended, and one of the constituent fibers is adjacent to the adjacent fused portions. The formation of a small diameter portion with two smaller fiber diameters The large diameter portion of the fiber having a larger diameter is sandwiched, and the hydrophilicity of the small diameter portion is made smaller than the hydrophilicity of the large diameter portion.

The method for producing a non-woven fabric according to the above <51>, wherein the fiber sheet is stretched in the extending step, and the fiber is formed in one of the constituent fibers between the adjacent fusion portions. a large diameter portion having a large fiber diameter sandwiched by a small diameter portion having a small fiber diameter, and a change point from the small diameter portion to the large diameter portion is formed from the fusion portion to the adjacent fusion portion Within one-third of the interval between the parts.

In the manufacturing method of the non-woven fabric according to the above <52>, the manufacturing apparatus used in the manufacturing method of the nonwoven fabric includes an extending portion, and the extending portion includes one pair of the first uneven roller and the second uneven roller that can mesh with each other. The distance (pitch) w between the large-diameter convex portions adjacent to each other in the roll axis direction of the first uneven roller, and the interval between the large-diameter convex portions adjacent to each other in the roll axis direction of the second uneven roller (interval) w is preferably 1 mm or more, more preferably 1.5 mm or more, and is preferably 10 mm or less, particularly preferably 8 mm or less, specifically 1 mm or more and 10 mm or less, preferably 1.5 mm or more and 8 mm or less.

The manufacturing method of the non-woven fabric according to any one of the above-mentioned <5>, wherein the first uneven roller and the second uneven roller have a pressing amount t (adjacent to the roller axis direction) The distance between the apex of the large-diameter convex portion of the uneven roller and the apex of the large-diameter convex portion of the second uneven roller is preferably 1 mm or more, more preferably 1.2 mm or more, and preferably 3 mm or less, and particularly preferably 2.5 mm. Hereinafter, specifically, it is 1 mm or more and 3 mm or less, and is preferably 1.2 mm or more and 2.5 mm or less.

The method for producing a non-woven fabric according to any one of the above-mentioned, wherein the first unevenness roller and the second uneven roller preferably have a mechanical stretch ratio of 1.5 or more, and more preferably 1.7. The ratio is preferably 3.0 or less, more preferably 2.8 or less, and specifically 1.5 or more and 3.0 or less, and preferably 1.7 or more and 2.8 or less.

<56> A non-woven fabric produced by the production method according to any one of the above <51> to <55>.

<57> An absorbent article comprising a front sheet disposed on the opposite side of the skin, a back sheet disposed on the non-skin opposing surface side, and an absorbent body interposed between the two sheets. And The front sheet is formed of the nonwoven fabric described in any one of the above <32> to <50> and <56>.

[Examples]

Hereinafter, the nonwoven fabric of the present invention will be described in more detail by way of examples. However, the scope of the invention is not limited by the embodiment.

[Example 1A]

The non-woven fabric of Example 1A in the form shown in Figs. 1 and 2 was produced by using the manufacturing apparatus 100 shown in Fig. 4 . The constituent fibers supplied to the manufacturing apparatus 100 are shown in Table 1 below. The composition of the fiber treating agent applied to the constituent fibers is as shown in Table 1, and the polyorganosiloxane is contained as a component having ductility in the fiber treating agent, and contains a hydrophilic component in addition to the ductile component. Hydrophobic component (alkyl phosphate, anionic surfactant). As shown in Table 1, the constituent fibers contained only high-stretch fibers, and were fibers having no elasticity (elastomer). Further, the high-stretch fiber-based core portion is polyethylene terephthalate and the sheath portion is a concentric core-sheath type composite fiber of polyethylene. The elongation of the high elongation fiber is 350%. In the manufacturing apparatus 100, the interval (pitch) between the large-diameter convex portions 404 and 404 of the pair of uneven rollers 401 and 402 is 2.0 mm, and the pressing amount of the pair of uneven rollers 401 and 402 is 1.2 mm, and The mechanical extension ratio is 1.9 times. Further, the application of the fiber treating agent to the constituent fibers is before the stretching step.

[Example 2A]

In the manufacturing apparatus 100 of the first embodiment, the amount of press-fitting of the pair of embossing rolls 401 and 402 is changed to 1.4 mm, and the mechanical stretching ratio is changed to 2.1 times. The non-woven fabric of Example 2A was produced in the same manner as in Example 1A.

[Example 3A]

In the manufacturing apparatus 100 of the first embodiment, the amount of press-fitting of the pair of embossing rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times, and the same manner as in the example 1A was carried out. Example 3A is not woven.

[Example 4A]

The nonwoven fabric of Example 4A was produced in the same manner as in Example 1A except that the composition of the fiber treating agent in Example 1A was changed as shown in Table 1.

[Example 5A]

The composition of the fiber treating agent in Example 1A was changed as shown in Table 1. In the manufacturing apparatus 100 of the first embodiment, the amount of press-fitting of the pair of embossing rolls 401 and 402 was changed to 1.4 mm, and the mechanical stretching ratio was changed to 2.1 times. A nonwoven fabric of Example 5A was produced in the same manner as in Example 1A except for the above.

[Example 6A]

The composition of the fiber treating agent in Example 1A was changed as shown in Table 1. In the manufacturing apparatus 100 of the first embodiment, the amount of press-fitting of the pair of uneven rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times. A nonwoven fabric of Example 6A was produced in the same manner as in Example 1A except the above.

[Example 7A]

The fiber treating agent in Example 1A was changed as shown in Table 1. The fiber treatment agent applied to the constituent fibers does not contain a ductile component and contains a hydrophilic component. A nonwoven fabric of Example 7A was produced in the same manner as in Example 1A except the above.

[Example 8A]

The composition of the fiber treating agent in Example 1A was changed as shown in Table 1. In the manufacturing apparatus 100 of the first embodiment, the amount of press-fitting of the pair of uneven rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times. In addition to these, The nonwoven fabric of Example 8A was produced in the same manner as in Example 1A.

[Example 9A]

The composition of the fiber treating agent in Example 1A was changed as shown in Table 1. Further, in the manufacturing apparatus 100 of the first embodiment, the amount of pressing of the pair of uneven rollers 401 and 402 was changed to 1.6 mm. A nonwoven fabric of Example 9A was produced in the same manner as in Example 1A except the above.

[Comparative Example 1A]

The constituent fibers in Example 1A were changed as shown in Table 1. The fiber treatment agent applied to the constituent fibers does not contain a ductile component and contains a hydrophilic component. Further, the application of the fiber treating agent to the constituent fibers is performed after the stretching step. A nonwoven fabric of Comparative Example 1A was produced in the same manner as in Example 1A except the above.

<evaluation>

With respect to the non-woven fabrics of Examples 1A to 9A and Comparative Example 1A, the thickness was measured by the above method, and the basis weight of the nonwoven fabric was calculated. The results are shown in Table 1 below. Moreover, the contact angle of the small diameter portion 16 and the large diameter portion 17 was measured by the above method. The results are shown in Table 1 below.

Further, regarding the nonwoven fabrics of Examples 1A to 9A and Comparative Example 1A, liquid residual property, dry touch property, and skin feel were evaluated by the following methods. The results are shown in Table 1 below.

[Evaluation of liquid residue]

The absorbent body was taken out from the commercially available product name "Water Absorbent Safety Relief (~80cc)" (manufactured in 2014), and the taken absorbent body was placed horizontally. The non-woven fabrics of Examples 1A to 7A or Comparative Example 1A were placed on the absorbent body, and a rectangular acrylic material having a cylindrical portion (having an inner diameter of 10 mm and a height of 40 mm) disposed at a center of 200 mm × 100 mm was placed on the absorbent body. board. 20 g of artificial urine was injected into the cylindrical portion at a rate of 5 g/sec in a state where the pressure applied by the acrylic plate was 0.5 kPa. After 7 seconds, the acrylic sheet was removed, and the commercially available toilet paper 2PL was folded 3 Next, the folded paper of about 5 cm × about 12 cm in size was placed on the injection port, and the pressure was applied at 0.5 kρa for 5 seconds. Thereafter, the pressure was released, and the weight (g) of the toilet paper absorbing artificial urine was measured. The weight (g) of the toilet paper before the artificial urine was absorbed was subtracted from the weight, and this value was taken as the residual amount (mg) of the liquid remaining in the nonwoven fabric. The smaller the value of the liquid residual amount (mg), the more excellent the liquid residual property was judged, and the evaluation was high.

Furthermore, the composition of artificial urine is as follows. 1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (hexahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788 mass% of potassium sulfate, 0.0035 mass% of polyoxyethylene lauryl ether and Ion exchange water (remaining amount).

[Evaluation of dryness of fingerless non-woven fabric]

The dryness of the non-woven fabric is measured by the "153.0-02 REPEATED Liquid Strike-Through Time" method of EDANA (European Nonwovens Industry Association) using the through-printing time measuring device Lister manufactured by Lenzing Technik. . The Liquid Strike-Through Time refers to the time (seconds) required for a specific amount of physiological saline to pass from the front side of the non-woven fabric to the back side. Specifically, 10 sheets of special filter paper were placed on the support of the test machine, and a non-woven fabric was placed thereon. Then, the plate having the electrode is placed on the non-woven fabric, and 10 ml of physiological saline (4.5 g of sodium chloride in 500 mL) is added from the liquid inlet port connected to the plate-transparent plate, and then the power of the testing machine is turned on. . The test machine measures the time (seconds) from the state of the physiological saline contact electrode to the time when the physiological saline passes through the non-woven fabric to lower the water level and the physiological saline does not contact the electrode. The measurement was performed 3 times, and the average value was set as the liquid permeation time of the non-woven fabric. The shorter the liquid permeation time, the less liquid residue on the surface, and the better the dryness of the finger touch.

[Evaluation of skin feel]

For the skin touch of the non-woven fabric, 10 adult women were asked for functional evaluation. Specifically, it is scored according to the score benchmark shown below, and will be targeted at all non-woven fabrics. The average value is rounded to the integer number to find out.

5 points: The texture of the non-woven fabric is very good.

4 points: The skin of the non-woven fabric feels good.

3 points: The texture of the non-woven fabric is normal.

2 points: The texture of the non-woven fabric is poor.

1 point: The skin of the non-woven fabric is very bad.

From the results of Table 1, it was found that the hydrophilicity of the small-diameter portion 16 of the non-woven fabrics of Examples 1A to 9A and the hydrophilicity of the large-diameter portion 17 were changed as compared with the nonwoven fabric of Comparative Example 1A. Further, in the non-woven fabrics of Examples 1A to 9A, the hydrophilicity of the small-diameter portion 16 is smaller than the hydrophilicity of the large-diameter portion 17. Further, it was found that the non-woven fabrics of Examples 1A to 9A had less liquid residue on the surface of the nonwoven fabric of Comparative Example 1A, and the dryness of the touch was good. Further, it was found that the non-woven fabrics of Examples 1A to 9A had not only the effect of good dryness of the touch but also the skin feel of the nonwoven fabric of the same or more than the non-woven fabric of Comparative Example 1A.

Hereinafter, the nonwoven fabric of the present invention (second invention) will be described in more detail by way of examples. However, the scope of the present invention (the second invention) is not limited to the embodiment.

[Example 1B]

The non-woven fabric of Example 1B in the form shown in Figs. 8 and 9 was produced by using the manufacturing apparatus 100B shown in Fig. 11 . The constituent fibers supplied to the manufacturing apparatus 100B are shown in Table 2 below. As shown in Table 2, the constituent fibers contained only high-stretch fibers, and were fibers having no elasticity (elastomer). Further, the high-stretch fiber-based core portion is polyethylene terephthalate and the sheath portion is a concentric core-sheath type composite fiber of polyethylene. The elongation of the high elongation fiber is 350%. In the manufacturing apparatus 100B, the interval (pitch) between the large-diameter convex portions 404 and 404 of the pair of uneven rollers 401 and 402 is 2 mm, and the pressing amount of the pair of uneven rollers 401 and 402 is 1.2 mm, and the mechanical amount is The stretching ratio is 1.9 times.

[Example 2B]

In the manufacturing apparatus 100B of the example 1B, the amount of press-fitting of the pair of uneven rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times, and the same manner as in the example 1B was carried out. Example 2B is not woven.

[Example 3B]

In the manufacturing apparatus 100B of the first embodiment, the amount of pressing of the pair of uneven rollers 401 and 402 is changed to 2.0 mm, and the mechanical stretching ratio is changed to 2.7 times. The nonwoven fabric of Example 3B was produced in the same manner as in Example 1B.

[Example 4B]

The non-woven fabric of Example 4B was produced in the same manner as in Example 1B except that the constituent fibers in Example 1B were changed to fibers having a high elongation fiber of 250%.

[Example 5B]

The non-woven fabric of Example 5B was produced in the same manner as in Example 2B except that the constituent fibers in Example 2B were changed to fibers having a high elongation fiber of 250%.

[Example 6B]

The non-woven fabric of Example 6B was produced in the same manner as in Example 3B except that the constituent fibers in Example 3B were changed to fibers having a high elongation fiber of 250%.

[Comparative Example 1B]

The constituent fibers in Example 1B were changed to the expanded composite fibers. Specifically, the conjugate fiber has an elongation of 80% of the extended fiber. A non-woven fabric of Comparative Example 1B was produced in the same manner as in Example 1B except that the fibers were changed.

[Comparative Example 2B]

The constituent fibers in Example 3B were changed to the expanded composite fibers. Specifically, the conjugate fiber has an elongation of 80% of the extended fiber. A non-woven fabric of Comparative Example 2B was produced in the same manner as in Example 3B except that the fibers were changed.

[Comparative Example 3B]

The non-woven fabric of Comparative Example 3B was formed by the method based on the manufacturing method described in Patent Document 1 so as to include the high-stretch fibers and the elastic fibers constituting the fibers in Example 4B. The amount of press-fitting and the mechanical stretching ratio of the pair of uneven rollers 401 and 402 are the same as those in the fourth embodiment.

[Comparative Example 4B]

In the method based on the production method described in Patent Document 1, the comparative example 4B was formed to include the high-stretch fibers and the elastic fibers constituting the fibers in Example 6B. Not woven. The amount of press-fitting and the mechanical stretching ratio of the pair of uneven rollers 401 and 402 were the same as those in the sixth embodiment.

<evaluation>

With respect to the non-woven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, the existence ratio of the change point 18 from the small-diameter portion 16 to the large-diameter portion 17 was evaluated by the following method, and when the change point 18 was present, The position of the change point 18 is measured. Moreover, the fiber diameters of the small diameter portion 16 and the large diameter portion 17 were measured by the above method. The results are shown in Table 2 below.

Further, regarding the non-woven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, the fiber density of the top portion 13a, the bottom portion 13b or the side portion 13c by the above method, and the top portion 13a, the bottom portion 13b or the side portion The number of change points 18 of the zone 13c was measured. The results are shown in Table 2 below.

Further, regarding the non-woven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, skin feel and liquid permeability were evaluated by the following methods. The results are shown in Table 2 below.

[Evaluation of the existence ratio of change point 18]

A total of 20 non-woven fabrics were randomly selected, and each of the constituent fibers was magnified 110 times using a scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd., and the presence or absence of the small diameter portion 16 to the large diameter was observed. Point 17 changes point 18. The existence ratio was calculated in the following manner. Existence ratio (%) = number of fibers with change point 18 / 20 x 100

Here, the change point 18 does not include a portion that gradually changes from the small diameter portion to the large diameter portion continuously or a portion that continuously changes from the small diameter portion to the large diameter portion due to the small diameter portion, and the configuration The state in which the first resin component constituting the core portion of the fiber is separated from the second resin component constituting the sheath portion and the fiber diameter is changed means a portion where the fiber diameter extremely changes.

[Evaluation of the position of change point 18]

When there is a change point 18, the adjacent fusion portions 12, 12 are spaced apart from each other. It is divided into three equal parts and divided into a region AT on the side of the fusion portion 12, a region BT on the side of the other fusion portion 12, and a central region CT. Further, it is observed in the region of the region AT, the region BT, or the central region CT where the change point 18 is disposed.

<evaluation result>

A: In the fiber having a change point, a fiber having a plurality of root point changes existing in the above region AT or the above region BT and also present in the central region CT.

B: Among the fibers having a change point, fibers having a plurality of root point changes existing only in the above region AT or the above region BT.

C: Among the fibers having a change point, a fiber having a plurality of root point changes existing only in the central region CT.

[Evaluation of skin feel of non-woven fabric]

20 observers were touched in a state where the non-woven fabric was not seen, and the feelings such as softness, softness, and cushioning properties were comprehensively used as the skin feel of the non-woven fabric, and evaluated according to the following five stages of criteria. The results are expressed as an average of 20 people.

<Evaluation criteria>

5: Very good

4: Good

3: ordinary

2: Poor

1: very bad

In addition, when the evaluation result of the average value of 20 is 4 or more, it is expected that the user can recognize the improvement of the skin feel and obtain a higher evaluation level.

[Evaluation of liquid permeability of non-woven fabric]

The liquid permeability of the non-woven fabric is based on the "153.0-02 REPEATED Liquid Strike-Through Time" method of the EDANA (European Nonwoven Industrial Association) using the through-printing time measuring device Lister manufactured by Lenzing Technik. Determination. The Liquid Strike-Through Time refers to the time (seconds) required for a specific amount of physiological saline to pass from the front side of the non-woven fabric to the back side. Specifically, 10 sheets of special filter paper were placed on the support of the test machine, and a non-woven fabric was placed thereon. Then, the plate having the electrode is placed on the non-woven fabric, and the physiological saline solution is added to the liquid inlet port connected to the plate-transparent plate (the Japanese Pharmacopoeia physiological salt solution manufactured by Otsuka Pharmaceutical Co., Ltd.) Then, the power of the testing machine is turned on. The testing machine measures the time from the state of the physiological saline contact electrode to the time when the physiological saline passes through the non-woven fabric to lower the water level and the physiological saline does not contact the electrode. The measurement is performed 3 times. The average value is set as the liquid permeation time of the non-woven fabric. The shorter the liquid permeation time, the better the liquid permeability.

According to the results of Table 2, it is understood that the non-woven fabrics of the first to sixth embodiments of the first to sixth embodiments have a change from the small-diameter portion 16 to the large-diameter portion 17 by the region AT or the region BT as compared with the nonwoven fabric of the comparative example 1B to the comparative example 4B. 18. In other words, adjacent to the fusion portion 12 that increases the rigidity of the nonwoven fabric In the manner of the small-diameter portion 16 having low rigidity, the softness of the nonwoven fabric is improved, and the skin feel is good.

Further, it is understood that the nonwoven fabrics of the first to sixth embodiments have a large number of side portions 13c in the position of the change point 18, so that the ridge portion 13 easily follows the movement of the wearer's skin and is a good skin feel. Further, it has been found that the nonwoven fabrics of the first to sixth embodiments have a large number of side portions 13c due to the position of the change point 18, and the side portion 13c has a low fiber density, so that the liquid permeability is good.

Further, according to the results of Table 2, the non-woven fabrics of Comparative Examples 1B to 2B were used because of the use of the extended fibers having a low elongation, so that the first resin component constituting the core portion of the fibers and the second resin component constituting the sheath portion were Extending to cause peeling. Therefore, the peeled portion of the sheath will smear the skin, and the touch of the skin is lowered. Since it is difficult to maintain the uneven shape, the core is exposed and dialed, so that the liquid passage time is reduced. Then, the non-woven fabric of Comparative Example 3B was constituted by incorporating the elastic fibers into the nonwoven fabric of Example 4B. When the elastic fiber is blended as described above, the nonwoven fabric is stretched while being shrunk. Therefore, even when the mechanical stretching ratio is the same, it is difficult to form a change point, and the fiber density is not easily lowered. Thereby, the non-woven fabric of Comparative Example 3B is less likely to have an effect of improving the skin feel and improving the liquid permeability. Then, the non-woven fabric of Comparative Example 4B was constructed by incorporating elastic fibers into the nonwoven fabric of Example 6B. When the elastic fiber is blended as described above, the non-woven fabric is stretched while being stretched, so that the portion where the fiber diameter of the present invention is extremely changed, that is, the change point is hard to occur, and the small-diameter portion 16 is gradually formed to gradually change toward the large-diameter portion 17. The part. In the non-woven fabric of Comparative Example 4B, since the elastic fiber was incorporated, the continuously gradually formed portion was hardly partially extended in the vicinity of the fusion point, and thus was not observed in the vicinity of the fusion point. As a result, the non-woven fabric of Comparative Example 4B is less likely to have an effect of improving the skin feel and improving the liquid permeability.

[Industrial availability]

According to the invention (first invention), the liquid residue on the surface is small, and the dryness of the touch is improved.

According to the invention (second invention), the skin feel can be made better.

1A‧‧‧Nonwoven

11‧‧‧constituting fibers

13‧‧‧Rocks

13a‧‧‧Top area

13b‧‧‧Bottom area

13c‧‧‧Side area

14‧‧‧ recessed section

A‧‧‧ non-woven front

b‧‧‧The back of the non-woven fabric

Y‧‧‧ direction

Z‧‧‧ Thickness direction

Claims (15)

A non-woven fabric comprising a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers, and the constituent fibers comprising high-stretch fibers, focusing on one of the constituent fibers, the constituent fibers being fused adjacent to each other The portions have a large diameter portion having a large fiber diameter sandwiched by two small diameter portions having a small fiber diameter, and the small diameter portion has a hydrophilicity smaller than that of the large diameter portion. The non-woven fabric of claim 1, wherein a fiber treating agent is adhered to the constituent fibers, and the fiber treating agent contains a ductile component. The non-woven fabric of claim 2, wherein the ductile component is a polyorganosiloxane. The non-woven fabric of claim 1, wherein the constituent fibers comprise only high-stretch fibers. In the non-woven fabric of claim 1, the change point from the small-diameter portion adjacent to the fusion portion to the large-diameter portion is disposed at a distance of 1/3 of the distance from the fusion portion to the adjacent portion of the fusion portion Within the scope. An absorbent article comprising a front sheet disposed on a side opposite to the skin, a back sheet disposed on a non-skin opposing side, and an absorbent interposed between the two sheets, and the front surface The sheet is formed by the non-woven fabric of claim 1. The non-woven fabric of claim 1, comprising a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers, and the constituent fibers comprising high-stretch fibers, focusing on one of the constituent fibers, the constituent fibers being in phase The adjacent fusion portions have a larger fiber diameter sandwiched by two small diameter portions having a smaller fiber diameter. The large-diameter portion is disposed within a range of one-third of a distance from the fusion portion to the adjacent portion of the fusion portion from the small-diameter portion adjacent to the fusion portion to the large-diameter portion. The non-woven fabric of claim 7, wherein the constituent fibers comprise only non-elastic fibers. In the non-woven fabric of claim 7, the one of the above-mentioned constituent fibers is focused on, and a plurality of the large-diameter portions are disposed between the adjacent fusion portions. In the non-woven fabric of claim 7, the non-woven fabric is a non-woven fabric having a concave-convex structure in which stripe-like ridge portions and concave strip portions extending in one direction are alternately arranged. The non-woven fabric of claim 10, wherein the non-woven fabric has a top region, a bottom region, and a side portion between the top, the top of the ridge portion is formed by the top portion, and the bottom portion of the concave portion is formed by the bottom portion. The fiber density of the side region is smaller than the fiber density of the top region and the fiber density of the bottom region. The non-woven fabric of claim 10, wherein the non-woven fabric has a top region, a bottom region, and a side portion between the top, the top of the ridge portion is formed by the top portion, and the bottom portion of the concave portion is formed by the bottom portion. The number of fibers having a change point in the constituent fibers constituting the side portion is larger than the number of fibers having a change point in the constituent fibers constituting the top portion and the number of fibers having a change point in the constituent fibers constituting the bottom portion . An absorbent article comprising a front sheet disposed on a side opposite to the skin, a back sheet disposed on a non-skin opposing side, and an absorbent interposed between the two sheets, and the front surface The sheet is formed by the non-woven fabric of claim 7. A manufacturing method of a non-woven fabric, comprising: a fusing step of thermally fusing an intersection of constituent fibers of a fiber web including a high-stretch fiber having a fiber treating agent through a fusion portion; and an extending step of the fusing After the step, the fused fiber web is extended in one direction; and in the extending step, the fiber web is extended, and two of the constituent fibers between the adjacent fused portions are formed by two The small-diameter portion having a small fiber diameter has a large diameter portion having a large fiber diameter, and the hydrophilic portion of the small-diameter portion is smaller than the hydrophilicity of the large-diameter portion. The method of manufacturing a non-woven fabric according to claim 14, wherein in the extending step, the fiber web is extended, and two fiber diameters are formed in one of the constituent fibers between the adjacent fusion portions. a large-diameter portion having a large fiber diameter sandwiched by the small-diameter portion, and a change point from the small-diameter portion to the large-diameter portion is formed at a distance from the fusion portion to the adjacent portion of the fusion portion Within the range of /3.