JP2015108202A - Nonwoven fabric and absorbent article including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric that permits a liquid to quickly pass therethrough, and is capable of effectively prevent the liquid from flowing along a surface and hardly allows the liquid to remain on the surface and the liquid to return.SOLUTION: The nonwoven fabric 10 has first projections 11 projecting on a first surface Z1 side and second projections 12 projecting on a second surface. The first projection 11 has a wall part 13 with an annular structure between its apex 11T and an opening 11H of its interior space. The first and second projections 11, 12 are alternatively and continuously arranged along two different directions X, Y which intersect each other when the nonwoven fabric 10 is planarly viewed. The nonwoven fabric 10 comprises fibers to which a fiber treating agent is attached. The fiber treating agent includes (A) polyorganosiloxane, (B) alkyl phosphate ester and (C) an anionic surfactant.

Description

  The present invention relates to a nonwoven fabric. Moreover, this invention relates to the absorbent article which has this nonwoven fabric.

  As a surface sheet of an absorbent article made of non-woven fabric, there are used a plurality of protrusions protruding toward the wearer's skin side, and the protrusions have an internal space where the absorber side is open. A technique is known (see Patent Document 1). A skin care agent is attached to the protruding portion of the nonwoven fabric constituting the surface sheet. And the adhesion amount of the skin care agent per unit area is larger on the skin facing surface than on the non-skin facing surface at the top.

  The technique described above relates to attaching a skin care agent to a nonwoven fabric used as a surface sheet. However, a technique of attaching a hydrophilizing agent to a nonwoven fabric instead of the skin care agent is also known. For example, the present applicant firstly heat-treats a core-sheath type composite fiber having a hydrophilizing agent attached to the surface thereof, and changes the hydrophilicity of the fiber, and the hydrophilicity is partially lowered using the technique. The technique which manufactures the nonwoven fabric which did it was proposed (refer patent document 2).

By the way, the thing which mix | blended the silicone type compound as a processing agent which processes a fiber is known, for example, in patent document 3, in order to prevent the sticking of the fiber at the time of manufacturing an elastic fiber, highly polymerized The use of an oil agent comprising a polyorganosiloxane and a base oil is described.
Patent Document 4 describes the use of an oil containing a highly polymerized polyorganosiloxane for the purpose of maintaining the dryness of the nonwoven fabric surface after contact with a liquid without inferior high-speed card properties. .

JP 2012-143543 A JP 2010-168715 A JP 2003-201678 A JP-A-5-51872

  However, in Patent Document 2, it is indispensable to use a heat-extensible fiber, and other fibers are not assumed, and further improvement is desired in terms of reducing the liquid residue on the surface of the surface sheet. It was rare.

Moreover, the technique of patent document 3 is a technique which prevents sticking of elastic fibers, and there is no suggestion that the oil agent used in the same document is used other than elastic fibers.
Furthermore, Patent Document 4 does not describe inclusion of an alkyl sulfate ester salt or an alkyl sulfonate in the oil agent described in the same document.

  Therefore, the subject of this invention is providing the nonwoven fabric which can eliminate the fault which the prior art mentioned above has, and an absorbent article which has it.

The present invention has a first surface and a second surface located on the opposite side,
A non-woven fabric having a plurality of first protrusions protruding toward the first surface and having an internal space, and a plurality of second protrusions protruding toward the second surface and having an internal space,
The first protrusion has a wall portion of an annular structure between the top and the opening of the internal space,
The first and second protrusions are arranged alternately and continuously along two different directions intersecting each other when the nonwoven fabric is viewed in plan view,
The non-woven fabric includes fibers to which a fiber treatment agent is attached,
The fiber treatment agent provides a nonwoven fabric containing the following component (A), component (B) and component (C).

（式中、Ｚはエステル基、アミド基、アミン基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数１〜１２の直鎖又は分岐鎖のアルキル鎖を表し、Ｒ₁及びＲ₂はそれぞれ独立に、エステル基、アミド基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数２〜１６の直鎖又は分岐鎖のアルキル基を表し、Ｘは―ＳＯ₃Ｍ、―ＯＳＯ₃Ｍ又は―ＣＯＯＭを表し、ＭはＨ、Ｎａ、Ｋ、Ｍｇ、Ｃａ又はアンモニウムを表す。） (A) Polyorganosiloxane (B) Alkyl phosphate ester (C) Anionic surfactant represented by the following general formula (1)

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

  ADVANTAGE OF THE INVENTION According to this invention, a liquid can be permeate | transmitted quickly, it is prevented effectively that a liquid flows along the surface, and the nonwoven fabric and absorbent article which a liquid does not remain on the surface are obtained. Moreover, the nonwoven fabric and absorbent article with which the liquid which once permeate | transmitted hardly occur can be obtained.

FIG. 1 is a perspective view showing an embodiment of the nonwoven fabric of the present invention. FIG. 2 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric shown in FIG. FIG. 3 is a schematic view showing an apparatus suitably used for manufacturing the nonwoven fabric shown in FIG. FIG. 4 is an enlarged view showing a main part of the support in the manufacturing apparatus shown in FIG. FIG. 5 is a schematic diagram showing a state where the web is shaped by the apparatus shown in FIG. FIG. 6 is a schematic view showing a state in which the fibers of the web are heat-sealed by the apparatus shown in FIG. FIG. 7 is a schematic view showing another apparatus suitably used for manufacturing the nonwoven fabric shown in FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The perspective view of one Embodiment of the nonwoven fabric of this invention is shown by FIG. FIG. 2 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric shown in FIG. The nonwoven fabric 10 shown in FIG.1 and FIG.2 has the 1st surface Z1 and the 2nd surface Z2 located in the other side. The nonwoven fabric 10 is preferably applied to a surface sheet of an absorbent article such as a sanitary napkin or a disposable diaper, and the first surface side Z1 is used facing the wearer's skin surface, and the second surface side Z2 is absorbed. It is preferable to arrange and use the absorbent article inside the absorbent article. Hereinafter, although it demonstrates considering the embodiment which uses the 1st surface side Z1 of the nonwoven fabric 10 shown in drawing toward a wearer's skin surface, this invention is limited to this and is not interpreted.

  The nonwoven fabric 10 uses an air-through nonwoven fabric as the nonwoven fabric 10 when the nonwoven fabric 10 is produced by a preferred method described later. The nonwoven fabric 10 has a single layer structure or a multilayer structure in which a plurality of layers are laminated. When the nonwoven fabric 10 has a multi-layer structure, each layer is distinguished depending on factors such as the type of fiber material constituting the layer, the thickness of the fiber, the presence or absence of a hydrophilic treatment, and the method of forming the layer. When the cross section in the thickness direction of the nonwoven fabric 10 is enlarged with an electron microscope, the boundary portion between both layers can be observed due to these factors.

  As shown in FIG.1 and FIG.2, the nonwoven fabric 10 has the some 1st protrusion part 11 which protrudes in the 1st surface side Z1 of the side which planarly viewed the sheet-like nonwoven fabric. The 1st protrusion part 11 has the internal space 11K with which the 2nd surface side was open | released. Moreover, the nonwoven fabric 10 has the several 2nd protrusion part 12 which protrudes in the 2nd surface side Z2 on the opposite side to the 1st surface side Z1. The second protrusion 12 has an internal space 12K that is open on the first surface side. These first and second protrusions 11 and 12 are arranged alternately and continuously along each of two different directions intersecting each other in plan view, for example, over the entire surface of the nonwoven fabric 10. The two different directions are, as a specific example, an X direction that is one direction of a different direction and a Y direction that is another direction different from the X direction. In the form shown in FIGS. 1 and 2, the convex portion viewed from the first surface side Z <b> 1 is the first projecting portion 11, and the concave portion is the second projecting portion 12. On the contrary, the convex part seen from the 2nd surface side Z2 is the 2nd protrusion part 12, and a recessed part becomes the 1st protrusion part 11. FIG. Therefore, the first protrusion 11 and the second protrusion 12 are partially shared.

  The first and second protrusions 11 and 12 have tops 11T and 12T, respectively. Moreover, the 1st, 2nd protrusion parts 11 and 12 have the wall parts 13 and 14 of an annular structure between the top parts 11T and 12T and the opening parts 11H and 12H of internal space, respectively. The top portions 11T and 12T are formed in a circular truncated cone shape or a hemispherical shape.

  If the first and second projecting portions 11 and 12 are viewed in more detail, the projecting shape of the first projecting portion 11 is somewhat hemispherical, while the projecting shape of the second projecting portion 12 is rounded at the top. It has a certain cone or truncated cone shape. In addition, in this embodiment, the 1st, 2nd protrusion parts 11 and 12 are not limited to the said shape, What kind of protrusion form may be sufficient. For example, it is practical to have various cone shapes (in this specification, the cone shape means a wide range including a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, and the like). In this embodiment, the 1st, 2nd protrusion parts 11 and 12 hold | maintain the frustoconical shape or hemispherical internal space 11K and 12K with the roundness in the top part similar to the outer diameter.

  The wall 13 located between the top of the first protrusion 11 (hereinafter also referred to as the first protrusion 11) 11T and the opening 11H forms an annular structure in the first protrusion 11. The wall 14 located between the top of the second protrusion 12 (hereinafter also referred to as the second protrusion top) 12T and the opening 12H forms an annular structure in the second protrusion 12. The wall portion 14 shares a part with a part of the wall portion 13. The “annular” is not particularly limited as long as it has an endless series of shapes in a plan view of the nonwoven fabric 10, and may be any shape such as a circle, an ellipse, a rectangle, or a polygon in the plan view of the nonwoven fabric 10. May be. From the viewpoint of suitably maintaining the continuous state of the nonwoven fabric 10, a circular shape or an elliptical shape is preferable. Furthermore, speaking of “annular” as a three-dimensional shape, a cylindrical shape, an oblique cylindrical shape, an elliptical columnar shape, a truncated cone shape, a truncated oblique cone shape, a truncated elliptical cone shape, a truncated rectangular pyramid shape, and a truncated oblique pyramid shape From the viewpoint of realizing a continuous sheet state, a cylindrical shape, an elliptic cylinder shape, a truncated cone shape, and a truncated elliptical cone shape are preferable.

  The non-woven fabric 10 having the first and second projecting portions 11 and 12 provided as described above does not have a bent portion, and is composed of a curved surface that is continuous as a whole. Thus, it is preferable that the nonwoven fabric 10 has a continuous structure in the surface direction. “Continuous” means that there are no intermittent portions or small holes. However, micropores such as gaps between fibers are not included in the small holes. The small hole can be defined, for example, as a hole having a diameter equivalent to a circle of 1.0 mm or more.

  In the nonwoven fabric 10, the fiber densities of the constituent fibers are different in the thickness direction. Specifically, the fiber density increases from the first protrusion top part 11T toward the second protrusion top part 12T. The fiber density is the mass of the fiber per unit volume of the nonwoven fabric 10. High fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 10 is large and the distance between fibers is small. Low fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 10 is small and the distance between fibers is large. Therefore, the part where the fiber density is high has a high capillary force, and the part where the fiber density is low has a low capillary force.

  When the fiber density is viewed along the thickness direction of the nonwoven fabric 10, the fiber density of the first protruding portion top portion 11T is the lowest and the fiber density of the second protruding portion top portion 12T is the highest. The fiber density of the wall parts 13 and 14 located between the 1st protrusion part top part 11T and the 2nd protrusion part top part 12T is the fiber density of the 1st protrusion part top part 11T, and the fiber density of the 2nd protrusion part top part 12T. It is an intermediate value. Thus, in the nonwoven fabric 10, the fiber density is higher in the order of the first protruding portion top portion 11T <wall portion 13, 14 <second protruding portion top portion 12T. Therefore, also about capillary force, capillary force becomes high in order of 1st protrusion part top part 11T <wall part 13,14 <2nd protrusion part top part 12T. In this case, the fiber density and the capillary force may be gradually increased in the order of the first protrusion top portion 11T <the wall portion 13, 14 <the second protrusion top portion 12T, or stepwise in a stepwise manner. It may increase. In order to impart such a fiber density gradient to the nonwoven fabric 10, the nonwoven fabric 10 may be manufactured according to the manufacturing method described later.

The specific value of the fiber density of the nonwoven fabric 10 is preferably 30 / mm ² or more, particularly 50 / mm ² or more, and 130 / mm ² or less, particularly 120, with respect to the first protrusion 11. / Mm ² or less is preferable. For example the fiber density of the first protrusion 11 is preferably 30 present / mm ² or more 130 present / mm ² or less, further preferably 50 present / mm ² or more, 120 / mm ² or less. On the other hand, regarding the 2nd protrusion part 12, it is preferable that it is 250 pieces / mm < ² > or more, especially 270 pieces / mm < ² > or more, 500 pieces / mm < ² > or less, and especially 480 pieces / mm < ² > or less are preferable. For example, the fiber density of the second protrusions 12 is preferably 250 / mm ² or more and 500 / mm ² or less, and more preferably 270 / mm ² or more and 480 / mm ² or less. The fiber density of the first protrusion 11 is measured at a position near the center of the layer thickness T _L1 in the first protrusion 11. The fiber density of the second protrusion 12 is measured at a position near the center of the layer thickness T _L2 in the second protrusion 12. The method for measuring the fiber density is as follows.

[Measurement method of fiber density]
The cut surface of the nonwoven fabric portion is magnified using a scanning electron microscope (adjusted to a magnification capable of measuring about 30 to 60 fiber cross sections; 150 to 500 times), and the cut per fixed area (about 0.5 mm ² ). The number of cross-sections of the fibers cut by the face was counted. Next, it was converted into the number of cross-sections of fibers per 1 mm ² and this was defined as the fiber density. The measurement was performed at three locations, and the fiber density of the sample was averaged.
Scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd.

Next, the dimension specification in the nonwoven fabric 10 of this embodiment is demonstrated. The thickness of the nonwoven fabric 10, the entire thickness of when the side view of the nonwoven fabric 10 and the sheet thickness T _S, the local thickness of the nonwoven fabric 10 which is curved in the unevenness and the layer thickness T _L. Sheet thickness _{T S} is may be adjusted as appropriate depending on the application, when used as a topsheet, such as diapers and sanitary products, preferably 1mm or 7mm or less, more preferably 5mm or 1.5 mm. By setting it as this range, the bodily fluid absorption speed | velocity at the time of use is quick, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable.

The layer thickness T _L may be different at each site in the nonwoven fabric 10 and may be appropriately adjusted depending on the application. When used as a topsheet, such as diapers and sanitary products, it is preferable, more preferably 0.4mm or more 2mm or less layer thickness _{T L1} of the first projecting portion top 11T is 0.1mm or more 3mm or less. The preferable ranges of the layer thickness T _{L2 of} the second protrusion top 12T and the layer thickness T _L3 of the walls 13 and 14 are the same as the layer thickness of the first protrusion top 11T. The relationship between the layer thicknesses T _L1 , T _L2 , and T _L3 is preferably T _L1 > T _L3 > T _L2 . Thereby, in the 1st protrusion part 11, especially on the skin surface side, fiber density is low and can implement | achieve favorable skin contact. On the other hand, the second protrusion 12 has a high fiber density, is not easily crushed, and can be made of a nonwoven fabric excellent in cushioning properties and liquid absorption speed without being deformed.

The sheet thickness T _S and the layer thickness T _L are measured by the following methods.
Method of measuring the thickness of the sheet T _S is in a state of applying a load of 0.05kPa nonwoven was measured with a thickness gauge. A laser displacement meter manufactured by OMRON Corporation was used as the thickness measuring instrument. The thickness was measured at 10 points, and the average value was calculated as the thickness.
Measurement of layer thickness T _L is to enlarge the cross section of the sheet at about 20 times by Keyence digital microscope VHX-900, you can measure the thickness of each layer.

The distance between the first protruding portion 11 and the second protruding portion 12 that are closest to the nonwoven fabric 10 when viewed in plan may be appropriately adjusted depending on the application. When used as a surface sheet for diapers, sanitary products, etc., 1 mm It is preferably 15 mm or less and more preferably 3 mm or more and 10 mm or less. The basis weight of the nonwoven fabric 10, depending on the specific application of the nonwoven fabric 10, preferably from 15 g / ^{m 2} or more 50 g / ^{m 2} or less the average value of the entire sheet, 20 g / ^{m 2} or more 40 g / ^{m 2} or less More preferred.

  In addition to the fiber density increasing from the first protrusion top 11T toward the second protrusion top 12T in the thickness direction, the nonwoven fabric 10 has the first protrusion 11T from the first protrusion top 11T in the thickness direction. 2 The hydrophilicity increases toward the protruding top portion 12T.

  When the hydrophilicity is seen along the thickness direction of the nonwoven fabric 10, the hydrophilicity of the first protruding portion top portion 11T is the lowest and the hydrophilicity of the second protruding portion top portion 12T is the highest. The hydrophilicity of the wall parts 13 and 14 located between the 1st protrusion part top part 11T and the 2nd protrusion part top part 12T is the hydrophilicity of the 1st protrusion part top part 11T, and the hydrophilicity of the 2nd protrusion part top part 12T. It is an intermediate value. Thus, in the nonwoven fabric 10, the hydrophilicity is higher in the order of the first protruding portion top portion 11T <wall portion 13, 14 <second protruding portion top portion 12T. In this case, the hydrophilicity may be gradually increased in the order of the first protrusion top portion 11T <the wall portion 13, 14 <the second protrusion top portion 12T, or may be increased stepwise. May be. In order to give such a gradient of hydrophilicity to the nonwoven fabric 10, the nonwoven fabric 10 may be manufactured according to the manufacturing method described later.

  The “hydrophilicity” referred to in the present invention is determined based on the contact angle of the fiber measured by the method described below. Specifically, a low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

[Measurement method of contact angle]
A fiber is taken out from a predetermined portion in the thickness direction of the nonwoven fabric, and the contact angle of water with the fiber is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The amount of liquid discharged from an ink jet type water droplet discharge part (manufactured by Cluster Technology, Inc., pulse injector CTC-25 having a discharge part pore diameter of 25 μm) is set to 20 picoliters, and a water drop is dropped directly above the fiber. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. The recording device is preferably a personal computer incorporating a high-speed capture device from the viewpoint of image analysis later. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water droplets landing on the fiber taken out from the air-through nonwoven fabric is the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2 Method, image processing algorithm is non-reflective, image processing image mode is frame, threshold level is 200, and curvature correction is not performed). Calculate the contact angle. The fiber taken out from the nonwoven fabric is cut into a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and kept horizontal. Two different contact angles are measured for each fiber. N = 5 contact angles are measured to one decimal place, and a value obtained by averaging a total of 10 measured values (rounded to the first decimal place) is defined as the contact angle.

  As described above, when the nonwoven fabric 10 is supplied with a liquid density gradient and a hydrophilicity gradient in the thickness direction of the nonwoven fabric 10, the liquid is supplied to the first surface Z1 side. Quickly penetrates through the nonwoven fabric 10. Accordingly, it is difficult for the liquid to flow along the surface on the first surface Z1 side. As a result, it is difficult for the liquid to remain on the surface on the first surface Z1 side, which is the surface supplied with the liquid. Moreover, the liquid that has once passed through the nonwoven fabric 10 is difficult to reverse. These remarkable effects become particularly remarkable when the nonwoven fabric 10 is used as a surface sheet of an absorbent article in which the surface on the first layer Z1 side is a skin facing surface.

  In particular, in the first projecting portion top portion 11T, it is preferable that the hydrophilicity is higher on the second surface Z2 side than on the first surface Z1 side. By doing so, the drawability of the liquid at the first protrusion top portion 11T is further increased, and when the liquid is supplied to the first surface Z1 side of the nonwoven fabric 10, the liquid quickly penetrates the nonwoven fabric 10 more quickly. become. From this viewpoint, the contact angle of water with respect to the fiber existing on the first surface side at the top of the first protrusion is preferably 65 degrees or more, particularly preferably 70 degrees or more, and 85 degrees or less, particularly 80 degrees or less. Is preferred. For example, the contact angle is preferably from 65 degrees to 85 degrees, and more preferably from 70 degrees to 80 degrees. On the other hand, the contact angle of water with respect to the fiber existing on the second surface side at the top of the first protrusion is smaller than the contact angle of water with respect to the fiber existing on the first surface at the top of the first protrusion. As above, it is preferably at least 65 °, particularly preferably at least 70 °, more preferably at most 85 °, particularly preferably at most 80 °. For example, the contact angle is preferably from 65 degrees to 85 degrees, and more preferably from 70 degrees to 80 degrees.

  From the viewpoint of making the above-mentioned effect in the first protrusion top portion 11T more prominent, the difference between the contact angle of water with respect to the fibers existing on the first surface side and the contact angle of water with respect to the fibers existing on the second surface side ( The former-the latter) is preferably 1 degree or more, preferably 20 degrees or less, particularly 10 degrees or less, and more preferably 4 degrees or less. For example, the difference in contact angle is preferably 1 degree or more and 20 degrees or less, more preferably 1 degree or more and 10 degrees or less, and still more preferably 1 degree or more and 4 degrees or less.

  Although the above description was the description regarding the 1st protrusion part top part 11T, it is preferable that it is as follows about the contact angles of the wall parts 13 and 14 and the 2nd protrusion part 12. FIG. The contact angle of water with respect to the fibers present in the walls 13 and 14 is 60 degrees or more, particularly 65, provided that the contact angle of water with respect to the fibers present on the second surface side of the first protrusion top 11T is smaller. It is preferably at least 80 °, more preferably at most 80 °, particularly preferably at most 75 °. For example, the contact angle is preferably 60 ° or more and 80 ° or less, and preferably 65 ° or more and 75 ° or less. When measuring the contact angle of water with the fibers present in the walls 13 and 14, the fiber collection site is the intermediate position between the first protruding portion top portion 11 </ b> T and the second protruding portion top portion 12 </ b> T in the thickness direction of the nonwoven fabric 10. And

  The contact angle of water with respect to the fibers existing in the second protrusion 12 is 60 degrees or more, particularly 65 degrees or more, provided that the contact angle of water with respect to the fibers existing in the walls 13 and 14 is smaller. Preferably, it is 80 degrees or less, and particularly preferably 75 degrees or less. For example, the contact angle is preferably 60 degrees or more and 80 degrees or less, and more preferably 65 degrees or more and 75 degrees or less. When measuring the contact angle of water with respect to the fiber which exists in the 2nd protrusion part 12, let the collection | recovery site | part of a fiber be a site | part on the 2nd surface side of the 2nd protrusion part top part 12T.

  From the viewpoint of making the permeability of the liquid in the nonwoven fabric 10 and the anti-reverse property of the liquid once permeated more remarkable, the contact angle of water with the fibers present on the second surface side of the first protrusion top 11T, and the wall The difference between the contact angle of water and the fibers present in the portions 13 and 14 (the former-the latter) is preferably 1 degree or more, particularly preferably 2 degrees or more, 20 degrees or less, particularly 10 degrees or less, and further 4 degrees or less. It is preferable that For example, the difference in contact angle is preferably 1 to 20 degrees, more preferably 2 to 10 degrees, and still more preferably 1 to 4 degrees.

  From the same viewpoint, the difference between the contact angle of water with respect to the fibers existing in the walls 13 and 14 and the contact angle of water with respect to the fibers present in the second protrusion 12 (the former-the latter) is preferably 1 degree or more, It is preferably 20 ° or less, particularly 7 ° or less, and more preferably 4 ° or less. For example, the difference in contact angle is preferably from 1 degree to 20 degrees, more preferably from 1 degree to 7 degrees, and still more preferably from 1 degree to 4 degrees.

  From the same viewpoint, the difference between the contact angle of water with respect to the fibers existing on the first surface side of the first protrusion top portion 11T and the contact angle of water with respect to the fibers existing in the second protrusion 12 (the former-the latter) is It is preferably 2 ° or more, particularly 4 ° or more, preferably 20 ° or less, particularly preferably 10 ° or less. For example, the difference in contact angle is preferably 2 degrees or more and 20 degrees or less, more preferably 4 degrees or more and 10 degrees or less.

The said fiber processing agent adhering to the fiber which comprises the nonwoven fabric 10 contains the following (A) component, (B) component, and (C) component.
(A) Polyorganosiloxane (B) Alkyl phosphate ester (C) Anionic surfactant represented by the general formula (1)

  The fiber treatment agent is preferably attached to the heat-fusible fiber among the fibers constituting the nonwoven fabric 10. By using the heat-fusible fiber to which the fiber treatment agent is adhered and adopting the manufacturing method described later, the nonwoven fabric 10 can be easily provided with a desired hydrophilicity gradient. In detail, the fiber treatment agent containing the anionic surfactant represented by (A) component, (B) component, and (C) component mentioned above, ie, polyorganosiloxane, alkyl phosphate ester, and General formula (1). In the case of the fiber with attached, the polyorganosiloxane promotes the penetration of the anionic surfactant having an alkyl chain into the fiber by heat-treating the fiber. To change. This is because the polysiloxane chain of the polyorganosiloxane and the alkyl chain of the anionic surfactant are incompatible with each other, so the anionic surfactant penetrates into the more familiar fiber when the fiber is heated and melted. It is thought to happen because of this. Among them, the anionic surfactant represented by the general formula (1) has a bulky alkyl group and can penetrate into the fiber so as to wrap around the hydrophilic group. Penetration into the fiber is easy to promote. Thus, for example, in the step of blowing hot air to the web, which is one step of the manufacturing process described later, the amount of heat received by the fibers in the web is naturally different between the hot air blowing surface and the surface on the opposite side. The amount of heat received is different between the surface fiber and the fiber on the opposite side, and the value of the contact angle of the fiber varies between the fiber on the hot air blowing surface and the fiber on the opposite side. Using this, a nonwoven fabric having a gradient in hydrophilicity is produced from one surface side, which is the first surface when viewed in plan, to the other surface side, which is the second surface opposite to the first surface. can do. Hereinafter, each component will be described.

[Component (A)]
As the polyorganosiloxane, any one having a straight chain or a crosslinked two-dimensional or three-dimensional network structure can be used. Preferably it is substantially linear.

  Specific examples of suitable polyorganosiloxanes are alkylalkoxysilanes, arylalkoxysilanes, alkylhalosiloxane polymers or cyclic siloxanes, and the alkoxy groups are typically methoxy groups. As the alkyl group, an alkyl group which may have a side chain having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms, particularly 1 to 4 carbon atoms is suitable. Examples of the aryl group include a phenyl group, an alkylphenyl group, and an alkoxyphenyl group. Instead of an alkyl group or an aryl group, a cyclic hydrocarbon group such as a cyclohexyl group or a cyclopentyl group, or an aralkyl group such as a benzyl group may be used. Further, the polyorganosiloxane referred to in the present invention is a polyorganosiloxane modified with a highly hydrophilic POE chain from the viewpoint of further promoting the penetration of the surfactant and increasing the contact angle of the fiber surface by heating. It is a concept that does not include.

  The most typical polyorganosiloxane preferred in the present invention includes polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane and the like, and polydimethylsiloxane is particularly preferred.

  The molecular weight of the polyorganosiloxane is preferably a high molecular weight. Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, preferably 1,000,000. Hereinafter, more preferably 800,000 or less, still more preferably 600,000 or less. Two or more types of polyorganosiloxanes having different molecular weights may be used as the polyorganosiloxane. When two or more types of polyorganosiloxanes having different molecular weights are used, one of them has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, and preferably Is not more than 1 million, more preferably not more than 800,000, still more preferably not more than 600,000. The other one has a weight average molecular weight of preferably less than 100,000, more preferably not more than 50,000, more preferably 30,000. It is 5,000 or less, more preferably 20,000 or less, preferably 2000 or more, more preferably 3000 or more, and still more preferably 5000 or more. Further, a preferable blending ratio (the former: latter) of the polyorganosiloxane having a weight average molecular weight of 100,000 or more and the polyorganosiloxane having a weight average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1. More preferably, it is 1: 5 to 2: 1.

The weight average molecular weight of the polyorganosiloxane is measured using GPC. The measurement conditions are as follows. The calculated molecular weight is calculated with polystyrene.
Separation column: GMHHR-H + GMHHR-H (cation)
Eluent: L Farmin DM20 / CHCl ₃
Solvent flow rate: 1.0 ml / min
Separation column temperature: 40 ° C

  The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, and more preferably 5% by mass or more from the viewpoint of increasing the change in hydrophilicity due to heat treatment. Moreover, 30 mass% or less is preferable from a viewpoint which is easy to absorb a liquid on the nonwoven fabric surface, and 20 mass% or less is still more preferable. For example, 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.

  A commercially available product can also be used as the polyorganosiloxane. For example, “KF-96H-1 million Cs” manufactured by Shin-Etsu Silicone Co., “SH200 Fluid 1000000 Cs” manufactured by Toray Dow Corning Co., Ltd. and those containing two types of polyorganosiloxane include “ KM-903 "or" BY22-060 "manufactured by Toray Dow Corning Co. can be used.

[(B) component]
The component (B), an alkyl phosphate ester, is intended to improve the properties of raw cotton through the card machine and the uniformity of the web, thereby improving the productivity of the nonwoven fabric and preventing the quality from deteriorating. It is blended in the treatment agent. Specific examples of the alkyl phosphate ester include those having a saturated carbon chain such as stearyl phosphate ester, myristyl phosphate ester, lauryl phosphate ester, palmityl phosphate ester, oleyl phosphate ester, palmitoleyl phosphate ester, etc. Examples include unsaturated carbon chains and those having side chains in these carbon chains. More preferably, it is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. Examples of the alkyl phosphate ester salt include alkali metals such as sodium and potassium, ammonia, and various amines. Alkyl phosphate ester can be used individually by 1 type or in mixture of 2 or more types.

  The blending ratio of the component (B) in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of card machine passability and web uniformity, etc. From the viewpoint of not hindering the hydrophobicity of the fibers by the resulting polyorganosiloxane, it is preferably 30% by mass or less, more preferably 25% by mass or less.

[Component (C)]
The component (C) is an anionic surfactant represented by the general formula (1) shown above. (C) component points out the component which does not contain the alkyl phosphate ester which is (B) component. Moreover, (C) component can be used individually by 1 type or in mixture of 2 or more types.

Examples of the anionic surfactant in which X in the general formula (1) is —SO ₃ M, that is, the hydrophilic group is a sulfonic acid or a salt thereof, include, for example, a dialkylsulfonic acid or a salt thereof. Specific examples of the dialkyl sulfonic acid include dioctadecyl sulfosuccinic acid, didecyl sulfosuccinic acid, ditridecyl sulfosuccinic acid, di-2-ethylhexyl sulfosuccinic acid, and the like, and dicarboxylic acids such as dialkyl sulfosuccinic acid and dialkyl sulfoglutaric acid. Saturated fatty acids and unsaturated fatty acids such as 2-sulfonadecanoic acid 1-ethyl ester (or amide) sodium salt and 2-sulfohexadecanoic acid 1-ethyl ester (or amide) sodium salt Alpha sulfo fatty acid alkyl esters (or amides) sulfonated at the α-position of esters (or amides), dialkyl alkenes obtained by sulfonating internal olefins of hydrocarbon chains and unsaturated fatty acids Such as sulfonic acid can be mentioned. The number of carbon atoms in each of the two-chain alkyl groups of the dialkyl sulfonic acid is preferably 4 or more and 14 or less, particularly 6 or more and 10 or less.

  Specific examples of the anionic surfactant in which the hydrophilic group is sulfonic acid or a salt thereof include the following anionic surfactants.

Examples of the anionic surfactant in which X in the general formula (1) is —OSO ₃ M, that is, the hydrophilic group is sulfuric acid or a salt thereof, include dialkyl sulfates. Specific examples thereof include 2-ethylhexyl. Compounds having sulfated alcohol such as sodium sulfate and sodium 2-hexyldecyl sulfate, alcohols having branched chain such as polyoxyethylene 2-hexyldecyl sulfate and polyoxyethylene 2-hexyldecyl sulfate Or a fatty acid ester (or 12-sulfate stearic acid 1-methyl ester (or amide) 3-sulfate hexanoic acid 1-methyl ester (or amide) or the like And compounds obtained by sulfating amides).

More specific examples of the anionic surfactant in which the hydrophilic group is sulfuric acid or a salt thereof include the following anionic surfactants.

  As the anionic surfactant in which X in the general formula (1) is —COOM, that is, the hydrophilic group is a carboxylic acid or a salt thereof, a dialkylcarboxylic acid can be mentioned, and specific examples thereof include 11-ethoxyhepta. Hydroxy fatty acid chlorides, such as compounds in which the hydroxy moiety of hydroxy fatty acids such as sodium decanecarboxylate and sodium 2-ethoxypentacarboxylate is alkoxylated and the fatty acid moiety is sodiumated, and the amino group of amino acids such as sarcosine and glycine are alkoxylated And compounds obtained by reacting carboxylic acid in the amino acid part with sodium, and compounds obtained by reacting fatty acid chloride with the amino group of arginic acid.

Specific examples of the anionic surfactant in which the hydrophilic group is a carboxylic acid or a salt thereof include the following anionic surfactants.

  In the present invention, as a fiber treating agent, a heat treating property treated with a fiber treating agent is obtained by using a fiber treating agent in which an anionic surfactant represented by the general formula (1) and polyorganosiloxane are blended. The fiber becomes a fiber whose hydrophilicity tends to be lowered by heat treatment. The reason for this is that polyorganosiloxane promotes the penetration of an anionic surfactant having two or more alkyl chains into the fiber, so that the hydrophilicity of the fiber surface tends to be lowered by heat treatment. This is because the polysiloxane chain of the polyorganosiloxane and the alkyl chain of the anionic surfactant are incompatible with each other, so that the anionic surfactant penetrates when the fiber is heated and melted into the more familiar fiber. Presumed to happen.

  The blending ratio of the component (C) in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass or more from the viewpoint of increasing the change in hydrophilicity due to heat treatment. When it becomes too high, it is preferably 20% by mass or less, more preferably 13% by mass or less, from the viewpoint of easily holding the liquid and impairing dryness. The blending ratio of the component (C) is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 13% by mass or less.

  The content ratio (the former: latter) of the polyorganosiloxane of the component (A) and the anionic surfactant of the component (C) in the fiber treatment agent is a mass ratio, preferably 1: 3 to 4: 1. More preferably, it is 1: 2 to 3: 1. Moreover, the content ratio (the former: latter) of the polyorganosiloxane of the component (A) and the alkyl phosphate ester of the component (B) in the fiber treatment agent is a mass ratio, preferably 1: 5 to 10: 1. Yes, more preferably 1: 2 to 3: 1.

  The fiber treatment agent used in the present invention may contain other components in addition to the components (A) to (C) described above. As other components to be blended in addition to the components (A) to (C), anionic, cationic, zwitterionic and nonionic surfactants can be used.

  Examples of anionic surfactants include alkyl phosphate sodium salt, alkyl ether phosphate sodium salt, dialkyl phosphate sodium salt, dialkyl sulfosuccinate sodium salt, alkylbenzene sulfonate sodium salt, alkyl sulfonate sodium salt, alkyl sulfate sodium salt, secondary Examples include alkyl sulfate sodium salt (all alkyls preferably have 6 to 22 carbon atoms, particularly preferably 8 to 22 carbon atoms). These may use other alkali metal salts such as potassium salts in place of sodium salts.

  Examples of the cationic surfactant include alkyl (or alkenyl) trimethyl ammonium halide, dialkyl (or alkenyl) dimethyl ammonium halide, alkyl (or alkenyl) pyridinium halide, and these compounds have 6 or more carbon atoms. Those having 18 or less alkyl groups or alkenyl groups are preferred. Examples of the halogen in the halide compound include chlorine and bromine.

Examples of the zwitterionic surfactant include alkyl (C1-30) betaine, alkyl (C1-30) amidoalkyl (C1-4) dimethylbetaine, alkyl (C1-30). Betaine-type zwitterionic surfactants such as dihydroxyalkyl (carbon number 1-30) betaine, sulfobetaine-type amphoteric surfactants, alanine type [alkyl (carbon number 1-30) aminopropionic acid type, alkyl (carbon Formula 1-30) Iminodipropionic acid type, etc.] Amphoteric surfactant, Glycine type such as alkylbetaine [Alkyl (C1-30) aminoacetic acid type, etc.] Amino acid type amphoteric surfactant, such as amphoteric surfactant, Examples thereof include aminosulfonic acid type amphoteric surfactants such as alkyl (C1-30) taurine type. Among them, betaine-type zwitterionic surfactants are preferable, alkyl (C1-30) betaines are more preferable, and alkylbetaines having 16 to 22 carbon atoms (for example, stearyl) are particularly preferable.

  Examples of nonionic surfactants include polyhydric alcohol fatty acid esters such as glycerin fatty acid ester, poly (preferably n = 2 to 10) glycerin fatty acid ester, sorbitan fatty acid ester (all preferably 8 to 8 carbon atoms of fatty acid). 60), polyoxyalkylene (addition mole number 2-20) alkyl (carbon number 8-22) amide, polyoxyalkylene (addition mole number 2-20) alkyl (carbon number 8-22) ether, polyoxyalkylene-modified silicone And amino-modified silicone.

  The fiber treating agent used in the present invention may contain a treating agent such as an anti-sticking agent such as modified silicone.

  Next, the fiber to which the fiber treatment agent is attached, which is included in the nonwoven fabric 10, will be described. The constituent fiber of the nonwoven fabric 10 has a higher degree of hydrophilicity on the surface of the fiber compared to before the fiber treatment agent is attached. The adhesion amount of the fiber treatment agent is preferably 0.1% by mass or more, more preferably 0.1% by mass or more from the viewpoint that the ratio of the fiber treatment agent to the total mass of the fiber excluding the fiber treatment agent increases the hydrophilicity of the fiber. It is 5 mass% or less, More preferably, it is 0.2 mass% or more and 1.0 mass% or less.

  As a method for attaching the fiber treatment agent to the surface of the fiber, various known methods can be employed without any particular limitation. For example, application by spraying, application by a slot coater, application by roll transfer, immersion in a fiber treatment agent, and the like can be mentioned. These treatments may be performed on the fibers before being made into a web, or after the fibers are made into a web by various methods. However, it is necessary to perform the process before the hot air blowing process described later. The fiber having the fiber treatment agent attached to the surface is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing type dryer.

  When the nonwoven fabric 10 is manufactured according to the method described later, the constituent fibers of the nonwoven fabric 10 are preferably heat-fusible fibers. Examples of the heat-fusible fiber include a heat-fusible core-sheath composite fiber, a non-heat-stretchable fiber, a heat-shrinkable fiber, a three-dimensional crimped fiber, a latent crimped fiber, and a hollow fiber. These fibers can be used alone or in combination of two or more. Of these fibers, it is particularly preferable to use a heat-fusible core-sheath composite fiber.

  The heat-fusible fiber has a heat-fusible property before and after the fiber treatment agent is attached, and has a core-sheath type composite structure. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or a deformed type. In particular, a concentric core-sheath type is preferable. Regardless of the form of the fibers, from the viewpoint of producing a flexible nonwoven fabric having good touch and the like, the fineness of the heat-fusible fiber is preferably 1.0 dtex or more and 10.0 dtex or less. More preferably, it is 0 dtex or more and 8.0 dtex or less.

  The fineness of the fibers may be the same throughout the thickness direction of the nonwoven fabric 10. Or you may differ in the 1st surface Z1 side and the 2nd surface Z2 side. When the fineness of the fiber is different between the first surface Z1 side and the second surface Z2 side, the fineness of the fiber present on the second surface Z2 side is smaller than the fineness of the fiber present on the first surface Z1 side. It is preferable. By doing so, a gradient in which the capillary force is further increased from the first surface Z1 side toward the second surface Z2 side is generated, and this is combined with the gradient of the hydrophilicity attributed to the fiber treatment agent, and the first surface Z1. The advantageous effect that the drawability of the liquid from the side toward the second surface Z2 side is improved is achieved. However, in the present invention, since the gradient of the hydrophilicity attributed to the fiber treatment agent and the gradient of the capillary force attributed to the fiber density are sufficiently imparted, a fiber having a small fineness is not used on the second surface Z2 side. However, the drawability of the liquid from the first surface Z1 side toward the second surface Z2 side is sufficient.

As described above, it is preferable to use a heat-fusible core-sheath type conjugate fiber as a constituent fiber of the nonwoven fabric 10. As a particularly preferred heat-fusible core-sheath type conjugate fiber, for example, JP 2010-168715 A “A core-sheath type composite fiber having a sheath part containing a polyethylene resin and a core part made of a resin component having a melting point higher than that of the polyethylene resin (hereinafter, this fiber is referred to as a core-sheath type composite fiber P)” Can be mentioned. Examples of the polyethylene resin constituting the sheath of the core-sheath type composite fiber P include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). In particular, high density polyethylene having a density of 0.935 to 0.965 g / cm ³ is preferable. The resin component constituting the sheath portion of the core-sheath type composite fiber P is preferably a polyethylene resin alone, but other resins can also be blended. Other resins to be blended include polypropylene resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and the like. However, as for the resin component which comprises a sheath part, it is preferable that 50 mass% or more in the resin component of a sheath part is especially 70 mass% or more and 100 mass% or less is a polyethylene resin. Further, the polyethylene resin constituting the sheath part of the core-sheath type composite fiber P preferably has a crystallite size of 10 nm or more and 20 nm or less, and more preferably 11.5 nm or more and 18 nm or less.

The sheath part of the core-sheath type composite fiber P plays a role of incorporating the above-described fiber treatment agent into the inside during heat treatment while imparting heat-fusibility to the heat-sealable core-sheath type composite fiber. On the other hand, a core part is a part which provides intensity | strength to a heat-fusible core-sheath-type composite fiber. As the resin component constituting the core part of the core-sheath type composite fiber P, a resin component having a melting point higher than that of the polyethylene resin that is the constituent resin of the sheath part can be used without particular limitation. Examples of the resin component constituting the core include polyolefin resins such as polypropylene (PP) (excluding polyethylene resin), polyester resins such as polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Furthermore, a polyamide-type polymer, the copolymer of 2 or more types of the resin component mentioned above, etc. can be used. A plurality of types of resins can be blended and used. In this case, the melting point of the core is the melting point of the resin having the highest melting point.
The heat-fusible core-sheath composite fiber to which the fiber treatment agent is attached has a difference in melting point between the resin component constituting the core part and the resin component constituting the sheath part (the former-the latter) at 20 ° C. or higher. It is preferable that the non-woven fabric is easily produced, and is preferably 150 ° C. or lower.

  The heat-fusible core-sheath composite fiber to which the fiber treatment agent is attached is preferably a heat-extensible fiber (hereinafter also referred to as a heat-extensible composite fiber) that is a fiber whose length is extended by heating. Examples of the heat-extensible fiber include a fiber that spontaneously extends as the crystal state of the resin changes due to heating. The heat-extensible fiber is present in the nonwoven fabric in a state where its length is extended by heating and / or in a state where it can be extended by heating. When heat-extensible fibers are heated, the fiber treatment agent on the surface is easily taken into the inside, and it becomes easy to form a plurality of portions having greatly different hydrophilicity by heat treatment in the fibers and the nonwoven fabric produced using the fibers.

A preferable heat-extensible conjugate fiber has a first resin component that constitutes a core portion and a second resin component that comprises a polyethylene resin and constitutes a sheath portion, and the first resin component is a second resin component. Has a higher melting point. A 1st resin component is a component which expresses the heat | fever extensibility of this fiber, and a 2nd resin component is a component which expresses heat-fusibility.
The melting points of the first resin component and the second resin component were determined by thermal analysis of a finely cut fiber sample (sample weight 2 mg) using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min. The melting peak temperature of each resin is measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the temperature at which the second resin component is fused to such an extent that the strength of the fusion point of the fiber can be measured is used as the temperature at which the molecular flow of the second resin component begins, and this is used instead of the melting point.

  The preferred orientation index of the first resin component in the heat-stretchable conjugate fiber is naturally different depending on the resin used. For example, in the case of a polypropylene resin, the orientation index is preferably 60% or less, more preferably 40% or less. More preferably, it is 25% or less. When the first resin component is polyester, the orientation index is preferably 25% or less, more preferably 20% or less, and still more preferably 10% or less. On the other hand, the second resin component preferably has an orientation index of 5% or more, more preferably 15% or more, and still more preferably 30% or more. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber. And when the orientation index of a 1st resin component and a 2nd resin component is each said value, a heat | fever extensible composite fiber comes to expand | extend by heating.

  The orientation index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP2010-168715A. Moreover, the method in which each resin component in the thermally stretchable conjugate fiber achieves the orientation index as described above is described in paragraphs [0033] to [0036] of JP-A No. 2010-168715.

  The heat stretchable conjugate fiber can be stretched by heat at a temperature lower than the melting point of the first resin component. The heat-extensible conjugate fiber preferably has a thermal elongation rate of 0.5 to 20% at a temperature 10 ° C. higher than the melting point of the second resin component (softening point in the case of a resin having no melting point). Preferably it is 3 to 20%, More preferably, it is 5.0 to 20%. A nonwoven fabric containing fibers having such a thermal elongation rate becomes bulky due to the elongation of the fibers or has a three-dimensional appearance. The thermal elongation rate of the fiber is determined by the method described in paragraphs [0031] to [0032] of JP2010-168715A.

  The ratio (mass ratio, the former: latter) of the first resin component and the second resin component in the heat-extensible conjugate fiber is 10:90 to 90:10, particularly 20:80 to 80:20, especially 50:50 to 70. : 30 is preferable. As the fiber length of the heat-extensible conjugate fiber, one having an appropriate length is used according to the method for producing the nonwoven fabric. For example, when the nonwoven fabric is manufactured by the card method as described later, the fiber length is preferably about 30 to 70 mm.

  The fiber diameter of the heat-extensible composite fiber is appropriately selected according to the specific use of the nonwoven fabric. When using a nonwoven fabric as a constituent member of an absorbent article such as a surface sheet of the absorbent article, it is preferable to use a nonwoven fabric having a thickness of 10 to 35 μm, particularly 15 to 30 μm. In addition, the fiber diameter of the heat-extensible composite fiber is reduced when the fiber diameter is reduced, and the fiber diameter is a fiber diameter when the nonwoven fabric is actually used.

  As the heat-extensible composite fiber, in addition to the above-described heat-extensible composite fiber, Japanese Patent No. 4131852, Japanese Patent Laid-Open No. 2005-350836, Japanese Patent Laid-Open No. 2007-303035, Japanese Patent Laid-Open No. 2007-204899, The fibers described in JP 2007-204901 A and JP 2007-204902 A can also be used.

  In the present invention, as the heat-fusible fiber, a fiber blended with a heat-extensible fiber and a non-heat-extensible fiber may be used. The non-heat-extensible fiber is a bicomponent composite fiber that includes a high-melting component and a low-melting component, and the low-melting component is continuously present in the length direction on at least a part of the fiber surface. The form of the composite fiber (non-heat-extensible fiber) includes various forms such as a core-sheath type and a side-by-side type, and any form can be used. The heat-fusible composite fiber is drawn at the raw material stage. The stretching treatment referred to here is a stretching operation with a stretching ratio of about 2 to 6 times. The mixing ratio of the heat-extensible fiber and the non-heat-extensible fiber is a mass ratio, and the former: the latter is preferably 1: 9 to 9: 1, and more preferably 4: 6 to 6: 4. Thereby, it becomes easier to recover the bulk of the nonwoven fabric with hot air, and an air-through nonwoven fabric having better touch and dryness than using each fiber alone can be obtained.

  When the nonwoven fabric 10 has a multilayer structure, for example, a two-layer structure, it is possible to easily make the gradient of hydrophilicity more remarkable. For example, on the upper side of the first layer having the above-described gradient of hydrophilicity, a second layer hydrophilized with a hydrophilizing agent called fiber oil agent is laminated, and the hydrophilicity of the first layer is higher than the hydrophilicity of the second layer. By increasing the degree, a non-woven fabric having a gradient in which the degree of hydrophilicity increases from the second layer toward the first layer can be obtained. The fiber oil agent used in this case has a lower hydrophilicity than that of the fiber treatment agent described above when applied to the fiber. In addition, as the fiber oil agent, one that does not easily penetrate into the inside of the fiber even when heat is applied is used.

  Moreover, the 2nd layer hydrophilized with the fiber oil agent is laminated | stacked under the 1st layer which has the gradient of the hydrophilicity mentioned above, and the hydrophilicity of a 2nd layer is raised rather than the hydrophilicity of a 1st layer. Thereby, the nonwoven fabric which has the gradient from which a hydrophilic degree becomes high toward a 2nd layer from a 1st layer can be obtained. The fiber oil agent used in this case has a higher degree of hydrophilicity when applied to the fibers than the hydrophilicity of the fiber treatment agent described above. In addition, as the fiber oil agent, one that does not easily penetrate into the inside of the fiber even when heat is applied is used.

  FIG. 3 shows a manufacturing apparatus that is preferably used to manufacture the nonwoven fabric 10. This apparatus is suitably used for manufacturing an air-through nonwoven fabric. Therefore, an air-through nonwoven fabric can be obtained by using this apparatus. As shown in the figure, the manufacturing apparatus 100 includes a support 110 that conveys a web 105 containing heat-fusible fibers. The web 105 is supplied to the surface of the support 110 by a feeding conveyor as the feeding unit 121. The web 105 is shaped by the support body 110, and the shaped web 105 is separated from the support body 110 and is sent out in a predetermined direction by a guide roller as a guide portion 122.

  The support 110 has a drum shape. Further, the support 110 is rotatable around the rotation shaft 110C. A driving device (not shown) is connected to the rotating shaft 110C. Details of the support 110 will be described later.

  A first nozzle 111 that blows the first hot air W1 and a second nozzle 112 that blows the second hot air W2 are provided on the outer surface side of the support 110 in order along the supply direction of the web 105. The first nozzle 111 includes a heater 113. The first hot air W <b> 1 heated by the heater 113 is blown, for example, substantially perpendicularly to the surface of the support 10 through the air-permeable conveyor 123 having air permeability.

  The first nozzle 111 is provided with a spray hole (not shown) at its tip. The length of the spray hole is preferably 1 mm or more and 20 mm or less in the machine direction (MD) of the web 105, and the length in the width direction (CD) of the web 105 is equal to or greater than the width of the web 105 or a width for shaping. It is. The spray holes have a shape in which one or more rows of slit holes are formed, and round holes, long holes, and square holes are arranged in a staggered manner or in parallel in one or more rows. Preferably, it has a slit shape in a row of 2 mm or more and 20 mm or less. Since the spray holes of the first nozzle 111 are formed in this way, the first hot air W1 is sprayed at a uniform wind speed in the width direction of the surface of the web 105. As the first hot air W1, air, nitrogen or water vapor heated to a predetermined temperature by the heater 113 can be used. Preferably, air that does not cost is used.

  The first hot air W <b> 1 blown from the first nozzle 111 is controlled by the heater 113 to a temperature at which the fibers of the web 105 are temporarily fused so that the concavo-convex shape is maintained. For example, when the constituent fiber of the web 105 is a core-sheath type composite fiber having a low melting point component and a high melting point component having a higher melting point than the low melting point component, the first hot air W1 is used as the low melting point component of the fiber of the web 105. It is controlled to be hot air at a temperature of 60 ° C. lower than its melting point and 15 ° C. lower than its melting point. Preferably, the temperature is controlled to be 50 ° C. or higher than the melting point of the low melting point component and 10 ° C. or lower than the melting point of the low melting point component. For example, when polyethylene having a melting point of 132 ° C. is used as the low melting point component, a preferable temperature range is from 82 ° C. to 142 ° C., more preferably from 132 ° C. to 142 ° C.

  The wind speed of the 1st hot air W1 is adjusted suitably. Preferably, the wind speed is controlled to be 10 m / sec or more and 120 m / sec or less. If the wind speed of the first hot air W1 blown from the first nozzle 111 is too slow, the fibers are not sufficiently along the support 110, and the fusion of the fibers is weakened, so that shaping is difficult. On the other hand, it is difficult to form the web 105 even if the wind speed is too high. Therefore, the wind speed of the first hot air W1 is preferably in the above range. More preferably, it is 20 m / sec or more and 80 m / sec or less, and particularly preferably 40 m / sec or more and 60 m / sec or less.

  The aeration conveyor 123 supplies the web 105 to the feeding side along the surface of the support 110 while sandwiching the web 105 with the support 110. Specifically, a belt 124 having air permeability, a plurality of rollers 125 that support the belt 124, and a drive device (not shown) that drives the belt 124 via the rollers 125 are provided. At least two rollers 125 </ b> A and 125 </ b> B of the plurality of rollers 125 are arranged on the surface of the support 110 so that the belt 124 extends along the web 5. The ventilation conveyor 123 can prevent the web 105 from being disturbed and scattered by the first hot air W1 from the first nozzle 111.

  The second nozzle 112 includes a heater 114. The second hot air W2 heated by the heater 114 is blown, for example, substantially perpendicularly to the surface of the support 10. The second nozzle 112 is provided with a spray hole (not shown) at its tip. As the spray hole, it is desirable to use a punching metal that is regularly opened in the width direction and the flow direction. The open area ratio is preferably 10% or more and 40% or less, and more preferably 20% or more and 30% or less. Thus, since the blowing hole of the second nozzle 112 is formed, the second hot air W2 is blown at a uniform wind speed in the width direction of the surface of the web 105. As the second hot air W2, air, nitrogen, or water vapor heated by the heater 114 can be used. Preferably, air that does not cost is used.

  The second hot air W2 is controlled by the heater 114 to a temperature at which the fibers 105 of the web 105 are fused to fix the uneven shape while holding the uneven shape of the web 105 formed by the first hot air W1. ing. For example, when the constituent fiber of the web 105 is a core-sheath type composite fiber having a low melting point component and a high melting point component having a higher melting point than the low melting point component, the second hot air W2 is a low melting point component of the web 105 fiber. It is controlled to a temperature not lower than the melting point and lower than the melting point of the high melting point component of the fibers of the web 105, preferably 40 ° C. or higher than the melting point of the low melting point component. More preferably, it is controlled to a temperature not lower than the melting point of the low melting point component and not higher than 20 ° C. above this melting point, particularly preferably not lower than the melting point of the low melting point component and not higher than 15 ° C. above this melting point. For example, when polyethylene having a melting point of 132 ° C. is used as the low melting point component, a more preferable temperature range is from 132 ° C. to 152 ° C., particularly preferably from 132 ° C. to 147 ° C.

  The wind speed of the second hot air W2 blown from the second nozzle 112 is appropriately determined in consideration of the purpose. Preferably, the wind speed is controlled to 1 m / sec or more and 10 m / sec or less. If the wind speed of the second hot air W2 blown from the second nozzle 112 is too slow, heat transfer to the fiber may not be sufficient, and the fiber may be difficult to fuse and the uneven shape may be insufficiently fixed. On the other hand, if the wind speed is too high, the fiber will be too hot and the texture will tend to be poor. Therefore, the wind speed of the second hot air W2 is preferably in the above range. More preferably, it is 1 m / sec or more and 8 m / sec or less, and particularly preferably 2 m / sec or more and 4 m / sec or less.

  In the blowing direction of the first nozzle 111, a suction section 115 that sucks the first hot air W1 that has passed through the aeration conveyor 123, the web 105, and the support 110 is disposed. An exhaust device 117 that exhausts the sucked first hot air W <b> 1 is connected to the suction unit 115. Further, in the blowing direction of the second nozzle 112, a suction part 116 for sucking the second hot air W2 that has passed through the web 105 and the support 110 is disposed. The suction unit 116 is connected to an exhaust device 118 that exhausts the sucked second hot air W2. Any of the suction portions can have a structure in which the length in the CD direction can be appropriately adjusted. By arranging such suction portions 115 and 116, the web is prevented from being disturbed due to the rebound of the air to be blown, etc., and can be stably shaped into a desired shape. Further, the temperature around the drum is prevented from becoming too high, and the web 105 in contact with the drum is prevented from being excessively fused and hardened. Furthermore, it becomes easy to hold the web 105 on the support 110, and the conveyance becomes easy. In consideration of the stabilization of hot air temperature and the running cost of utilities, it is desirable to circulate and use hot air.

FIG. 4 is an enlarged view of a main part of the support 110 in the apparatus 100 shown in FIG. 4 corresponds to a state in which the support 110 having the shape of the peripheral surface of the drum in FIG. 3 is formed into a flat plate shape. The support 110 has a base 110B made of a plate-like body. A large number of through holes are formed in the base portion 110B, and the through holes serve as ventilation portions 110H that are concave portions. Moreover, the support body 110 has a plurality of protruding portions 110T that stand up from one surface of the base portion 110B. The protrusion 110T is located between the adjacent ventilation portions 110H. The protruding portions 110T and the ventilation portions 110H are alternately arranged along the A direction which is one direction in the plane of the support 110. Further, the protruding portions 110T and the ventilation portions 110H are alternately arranged along the B direction which is another direction in the plane of the support 110. The A direction and the B direction are orthogonal to each other. When viewed along the A direction, the distance d _A between the adjacent protruding portion 110T and the ventilation portion 110H, and when viewed along the B direction, the adjacent protruding portion 110T and the ventilation portion 110H the distance d _B between may be may be the same or different. The A direction coincides with the rotation direction of the support 110, and the B direction coincides with the width direction of the support 110. Thus, the support body 110 has an uneven structure on one surface of the base portion 110B.

  The protrusion 110T has a shape that tapers toward the tip, and the tip is rounded. The protruding portion 110T has, for example, a plate shape or a spindle shape. The height of the protruding portion 110T can be appropriately set according to the use, standard, etc. of the nonwoven fabric. The height H of the protrusion 110T (see FIG. 4), that is, the height based on the upper surface of the base 110B is preferably 3 mm to 30 mm, more preferably 3 mm to 10 mm. The pitch of the protrusions 110T is preferably 6 mm to 15 mm, more preferably 6 mm to 10 mm in the A direction, and preferably 4 mm to 8 mm, and more preferably 4 mm to 6 mm in the B direction.

  The ventilation portion 110H of the support 110 is composed of a plurality of openings formed in the support 110, and the opening ratio is preferably 20% or more and 45% or less, more preferably 25% or more with respect to the surface area of the support 110. It is set to 40% or less, more preferably 30% to 35%. By setting the aperture ratio within this range, a sufficient uneven shape can be formed on the web 105, and the deterioration of the shaped shape and the formation of fluff are effectively prevented.

  The shape of the ventilation portion 110H can be, for example, a circle in plan view. However, the shape of the ventilation part 110H is not limited to this, and other shapes such as an ellipse, a polygon, or a combination thereof may be employed.

  FIG. 5 schematically shows a state in which the web 105 is shaped using the support 110. In FIG. 5, the ventilation conveyor 123 is not shown. In a state where the web 105 is placed on the support 110, the first hot air W1 is blown from the outer surface of the web 105. The blown first hot air W1 passes through the web 105, further passes through the ventilation portion 110H of the support 110, and is sucked by the suction portion 115 (see FIG. 3). Thus, the 1st hot air W1 is sprayed with respect to the web 105 by an air through system.

  A portion of the web 105 spanned by two or more adjacent projecting portions 110T receives pressure by the blowing of the first hot air W1 and deforms downward. The protrusion 11A is formed by this deformation. The protruding portion 11A is a portion corresponding to the first protruding portion 11 in the target nonwoven fabric 10. In the protrusion 11 </ b> A, the closer to the bottom, the greater the degree of deformation due to the pressure due to the blowing of the first hot air W <b> 1, and as a result, the inter-fiber distance becomes larger than the second protrusion 12. . In other words, the fiber density is reduced.

  On the other hand, even if the portion of the web 105 supported by the protruding portion 110T receives pressure due to the blowing of the first hot air W1, the downward deformation is suppressed by the restriction by the protruding portion 110T. As a result, the portion supported by the protruding portion 110T has a convex shape with a skirt extending downward. This convex-shaped part is a part corresponding to the 2nd protrusion part 12 in the target nonwoven fabric 10. FIG. At the highest position of the convex portion, the inter-fiber distance is small. In other words, the fiber density is increased. On the other hand, since the web 105 is deformed at the base of the convex portion, the inter-fiber distance is larger than that of the first protruding portion 11. In other words, the fiber density is reduced. However, it does not become as small as the fiber density of the protrusion 11A (see FIG. 5) described above.

  As described above, a gradient is generated in the fiber density along the thickness direction of the shaped web 105 by the blowing of the first hot air W1. This gradient is a gradient in which the fiber density decreases from the surface to which the first hot air W1 is blown toward the opposite surface. In FIG. 5, a two-dot chain line indicates the fiber web 105 after shaping.

  In this manufacturing method, a gradient occurs in the fiber density along the thickness direction of the shaped web 105, and at the same time, a gradient also occurs in the hydrophilicity along the thickness direction of the shaped web 105. The reason is as follows. According to the blowing of the first hot air W1, the protruding portion 11A, which is a portion of the web 105 that has been deformed under the pressure of the blowing of the first hot air W1, has the largest amount of passage of the first hot air W1. . In other words, it receives the largest amount of heat. As a result, in the protruding portion 11A, the degree of penetration of the fiber treatment agent into the fiber increases, and as a result, the hydrophilicity is lower than before the first hot air W1 is blown. On the other hand, the portion of the support 110 that is supported by the protrusion 110T is relatively less deformed by the blowing of the first hot air W1 than the protrusion 11A, and therefore the first hot air W1 passes by that much. The amount is relatively small. Due to this, in the portion supported by the protrusion 110T, the degree of penetration of the fiber treatment agent into the fiber becomes relatively small, and as a result, compared with before the first hot air W1 is blown. The degree of decrease in hydrophilicity is reduced.

  As described above, the lower the degree of hydrophilicity the closer to the base 110B in the web 105 due to the blowing of the first hot air W1, the greater the degree of hydrophilicity the closer to the part supported by the protrusion 110T. The gradient of hydrophilicity that the degree of decrease becomes small appears.

  FIG. 6 shows a state where the target nonwoven fabric 10 is obtained by blowing the second hot air W2 to the shaped web 105 and fusing the intersections of the constituent fibers. The second hot air W2 is blown by an air-through method.

  The nonwoven fabric 10 thus obtained can be applied to various fields by taking advantage of the gradient of fiber density and the gradient of hydrophilicity along the uneven shape. For example, a top sheet, a second sheet (a sheet disposed between the top sheet and the absorbent body) in an absorbent article used to absorb liquid discharged from the body such as sanitary napkins, panty liners, disposable diapers, and incontinence pads , A back sheet, a leak-proof sheet, or a personal wipe sheet, a skin care sheet, and an objective wiper. When using the nonwoven fabric 10 as a surface sheet or a second sheet of an absorbent article, it is preferable to use the first surface Z1 side of the air-through nonwoven fabric as the skin facing surface side.

  An absorbent article used for absorbing liquid discharged from the body typically includes a top sheet, a back sheet, and a liquid-retaining absorbent body interposed between both sheets. As the absorber and the back sheet when the air-through nonwoven fabric of the present invention is used as the top sheet, materials usually used in the technical field can be used without particular limitation. For example, as the absorbent body, a fiber assembly made of a fiber material such as pulp fiber or a fiber assembly in which an absorbent polymer is held can be coated with a covering sheet such as tissue paper or nonwoven fabric. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability. The absorbent article may further include various members according to specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when applying an absorbent article to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the manufacturing apparatus 100 shown in FIG. 3, as shown in FIG. 7, the belt 124 of the aeration conveyor 123 is extended to the position where the second nozzle 112 is arranged, and the second hot air is directed from the second nozzle 112 toward the web 105. When spraying W2, the web 105 may be sandwiched between the belt 124 and the support 110.

（式中、Ｚはエステル基、アミド基、アミン基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数１〜１２の直鎖又は分岐鎖のアルキル鎖を表し、Ｒ₁及びＲ₂はそれぞれ独立に、エステル基、アミド基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数２〜１６の直鎖又は分岐鎖のアルキル基を表し、Ｘは―ＳＯ₃Ｍ、―ＯＳＯ₃Ｍ又は―ＣＯＯＭを表し、ＭはＨ、Ｎａ、Ｋ、Ｍｇ、Ｃａ又はアンモニウムを表す。） This invention discloses the following nonwoven fabrics further regarding embodiment mentioned above.
<1>
Having a first surface and a second surface opposite to the first surface;
A non-woven fabric having a plurality of first protrusions protruding toward the first surface and having an internal space, and a plurality of second protrusions protruding toward the second surface and having an internal space,
The first protrusion has a wall portion of an annular structure between the top and the opening of the internal space,
The first and second protrusions are arranged alternately and continuously along two different directions intersecting each other when the nonwoven fabric is viewed in plan view,
The non-woven fabric includes fibers to which a fiber treatment agent is attached,
The nonwoven fabric in which the said fiber processing agent contains the following (A) component, (B) component, and (C) component.
(A) Polyorganosiloxane (B) Alkyl phosphate ester (C) Anionic surfactant represented by the following general formula (1)

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

<2>
The nonwoven fabric according to <1>, wherein the hydrophilicity increases in the order of the first protrusion, the wall, and the second protrusion.
<3>
The nonwoven fabric according to <1> or <2>, wherein the hydrophilicity is higher on the second surface side than on the first surface side at the top of the first protrusion.
<4>
The non-woven fabric according to <3>, wherein a contact angle of water with respect to fibers existing on the first surface side at the top of the first protrusion is 65 degrees or more and 85 degrees or less.
<5>
The contact angle of water with respect to the fibers present on the first surface side at the top of the first protrusion is preferably 65 degrees or more, particularly preferably 70 degrees or more, and preferably 85 degrees or less, particularly preferably 80 degrees or less. The nonwoven fabric as described in 3> or <4>.
<6>
The non-woven fabric according to any one of <3> to <5>, wherein a contact angle of water with respect to fibers existing on the second surface side at the top of the first protrusion is 65 degrees or more and 85 degrees or less.

<7>
On the condition that the contact angle of water with respect to the fibers present on the second surface side at the top of the first protrusion is smaller than the contact angle of water with respect to the fibers present on the first surface at the top of the first protrusion. The non-woven fabric according to any one of <3> to <6>, preferably 65 ° or more, particularly preferably 70 ° or more, and preferably 85 ° or less, particularly preferably 80 ° or less.
<8>
At the top of the first protrusion, the difference between the contact angle of water with the fiber existing on the first surface side and the contact angle of water with the fiber on the second surface side (the former-the latter) is 1 degree or more and 20 degrees. The nonwoven fabric according to any one of <3> to <7>, which is the following.
<9>
The difference between the contact angle of water with respect to the fibers present on the first surface side and the contact angle of water with respect to the fibers present on the second surface side (the former-the latter) is preferably 1 degree or more, preferably 20 degrees or less. In particular, the nonwoven fabric according to any one of <3> to <8>, preferably 10 degrees or less, and more preferably 4 degrees or less.
<10>
The non-woven fabric according to any one of <1> to <9>, wherein a contact angle of water with respect to fibers existing in the second protrusion is 60 degrees or greater and 80 degrees or less.
<11>
The contact angle of water with respect to the fibers existing in the second protrusion is preferably 60 degrees or more, particularly preferably 65 degrees or more, provided that the contact angle of water with respect to the fibers existing in the wall is smaller. Hereinafter, the nonwoven fabric according to any one of <1> to <10>, particularly preferably 75 degrees or less.

<12>
The non-woven fabric according to any one of <1> to <11>, wherein a contact angle of water with respect to fibers existing in the wall is 60 degrees or greater and 80 degrees or less.
<13>
The contact angle of water with the fibers present in the wall is 60 degrees or more, particularly 65 degrees or more, provided that the contact angle of water with the fibers present on the second surface side of the top of the first protrusion is smaller. The nonwoven fabric according to any one of <1> to <12>, preferably 80 degrees or less, particularly preferably 75 degrees or less.
<14>
The difference (the former-the latter) between the contact angle of water with respect to the fiber existing on the second surface side at the top of the first protrusion and the contact angle of water with respect to the fiber existing on the wall is 1 degree or more and 20 degrees or less. The nonwoven fabric according to any one of <1> to <13>.
<15>
The difference between the contact angle of water with the fiber existing on the second surface side at the top of the first protrusion and the contact angle of water with the fiber existing on the wall (the former-the latter) is 1 degree or more, particularly 2 degrees or more. The nonwoven fabric according to any one of <1> to <14>, which is preferably 20 degrees or less, particularly preferably 10 degrees or less, and more preferably 4 degrees or less.
<16>
<1> to <15, wherein the difference between the contact angle of water with respect to the fibers present in the wall portion and the contact angle of water with respect to the fibers present in the second protrusion (the former-the latter) is not less than 1 degree and not more than 20 degrees. > Any one of>.

<17>
The difference between the contact angle of water with respect to the fibers existing in the wall portion and the contact angle of water with respect to the fibers present in the second protrusion (the former-the latter) is preferably 1 degree or more, 20 degrees or less, particularly 7 degrees or less, Furthermore, the nonwoven fabric according to any one of <1> to <16>, preferably 4 degrees or less.
<18>
The difference between the contact angle of water with respect to the fibers existing on the first surface side at the top of the first protrusion and the contact angle of water with respect to the fibers existing in the second protrusion (the former-the latter) is 2 degrees or more, particularly 4 degrees. The non-woven fabric according to any one of <1> to <17>, wherein the above is preferable, and preferably 20 degrees or less, particularly preferably 10 degrees or less.
<19>
The nonwoven fabric according to any one of <1> to <18>, wherein the fibers present on the second surface side are thinner than the fibers present on the first surface side.
<20>
The nonwoven fabric according to any one of <1> to <19>, wherein the polyorganosiloxane as the component (A) is polydimethylsiloxane.
<21>
The molecular weight of the polyorganosiloxane as the component (A) is preferably a high molecular weight. Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 150,000 or more, and still more preferably 200,000 or more. The nonwoven fabric according to any one of <1> to <20>, preferably 1 million or less, more preferably 800,000 or less, and still more preferably 600,000 or less.

<22>
The nonwoven fabric according to any one of <1> to <21>, wherein two or more types of polyorganosiloxanes having different molecular weights are used as the polyorganosiloxane that is the component (A).
<23>
Two or more types of polyorganosiloxanes having different molecular weights are used as the component (A), and one of them has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, and still more preferably 200,000 or more. And preferably 1 million or less, more preferably 800,000 or less, still more preferably 600,000 or less, and the other one is a weight average molecular weight of preferably less than 100,000, more preferably 50,000 or less, More preferably, it is 35,000 or less, more preferably 20,000 or less, preferably 2000 or more, more preferably 3000 or more, still more preferably 5000 or more, any one of the above items <1> to <22> The nonwoven fabric described in 1.
<24>
A preferable blending ratio (the former: latter) of the polyorganosiloxane having a weight average molecular weight of 100,000 or more and the polyorganosiloxane having a weight average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1. Preferably the nonwoven fabric as described in said <23> which is 1: 5-2: 1.
<25>
The <1> to <24>, wherein the polyorganosiloxane as the component (A) is contained in a ratio of 1% by mass to 30% by mass with respect to the total mass of the fiber treatment agent. Non-woven fabric.
<26>
The content of the polyorganosiloxane as the component (A) 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, The non-woven fabric according to any one of <1> to <27>, further preferably having a mass% or less.

<27>
(B) The alkyl phosphate ester which is the component is any one of the above <1> to <26>, wherein the mono- or dialkyl phosphate ester having a carbon chain of 16 to 18 is a completely neutralized or partially neutralized salt. Non-woven fabric.
<28>
The blending ratio of the component (B) in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less. The nonwoven fabric according to any one of 1> to <27>.
<29>
The nonwoven fabric according to any one of <1> to <28>, wherein the component (C) is a dialkylsulfonic acid or a salt thereof.
<30>
The blending ratio of the component (C) in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 20% by mass or less, more preferably 13% by mass or less. The nonwoven fabric according to any one of <1> to <29>.
<31>
The content ratio (the former: latter) of the polyorganosiloxane of the component (A) and the anionic surfactant of the component (C) in the fiber treatment agent is a mass ratio, preferably 1: 3 to 4: 1. The nonwoven fabric according to any one of <1> to <30>, more preferably 1: 2 to 3: 1.

<32>
The content ratio (the former: latter) of the polyorganosiloxane of the component (A) and the alkyl phosphate ester of the component (B) in the fiber treatment agent is a mass ratio, preferably 1: 5 to 10: 1. The nonwoven fabric according to any one of <1> to <31>, more preferably 1: 2 to 3: 1.
<33>
The nonwoven fabric according to any one of <1> to <32>, wherein a heat-extensible fiber is used as the constituent fiber.
<34>
The heat-extensible fiber is a heat-extensible composite fiber, and the heat-extensible composite fiber has a thermal elongation rate at a temperature 10 ° C. higher than the melting point of the second resin component (softening point in the case of a resin having no melting point). Is preferably 0.5 to 20%, more preferably 3 to 20%, and still more preferably 5.0 to 20%, according to <33>.
<35>
The nonwoven fabric according to any one of <1> to <34>, wherein the fiber density increases from the top of the first protrusion toward the top of the second protrusion.
<36>
The nonwoven fabric according to any one of <1> to <35>, wherein the fiber density increases in the order of the first protrusion top portion <wall portion <second protrusion top portion.

<37>
Fiber density of the first protrusion, 30 lines / mm ² or more, preferably particularly 50 present / mm ² or more, 130 present / mm ² or less, wherein it is particularly preferably 120 present / mm ² or less < The nonwoven fabric according to any one of 1> to <36>.
<38>
Fiber density of the second protrusion 250 present / mm ² or more, preferably particularly 270 present / mm ² or more, 500 / mm ² or less, particularly 480 / mm ² or less is preferably the < The nonwoven fabric according to any one of 1> to <37>.
<39>
In an absorbent article including a top sheet, a back sheet, and an absorbent body disposed between both sheets, the non-woven fabric according to any one of <1> to <38> is used as the top sheet, An absorbent article arranged so that one surface faces the wearer's skin.
<40>
The non-woven fabric according to any one of <1> to <38>, wherein the protruding shape of the first protruding portion is hemispherical, and the protruding shape of the second protruding portion is a cone or a truncated cone shape with a rounded top.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” means “mass%”.

[Examples 1 and 2]
The air through nonwoven fabric of the form shown in FIG.1 and FIG.2 was manufactured using the manufacturing apparatus 100 shown in FIG.3 and FIG.4. The fibers of the web 105 supplied to the manufacturing apparatus 100 are shown in Table 1 below. The table also describes the composition of the fiber treatment agent applied to the fibers. Conditions in the manufacturing apparatus 100 are also described in the table. Thus, the air through nonwoven fabric of the single layer structure which has the basic weight shown to the same table was obtained. The heat-fusible fiber shown in Table 1 is a concentric core-sheath type composite fiber whose core is polyethylene terephthalate and whose sheath is polyethylene, and the mass ratio between the core and the sheath is core: sheath = 50: 50. Yes, the fineness was 3.3 dtex, and the fiber length was 51 mm.

[Examples 3 and 4]
In this example, an air-through nonwoven fabric having a multilayer structure consisting of two layers was produced. The heat-fusible fiber shown in Table 1 is a concentric core-sheath type composite fiber in which the core is polyethylene terephthalate and the sheath is polyethylene. The mass ratio was core: sheath = 50: 50, the fineness was 3.3 dtex, and the fiber length was 51 mm. The fiber of the layer on the second protrusion 12 side is a concentric core-sheath type composite fiber whose core is polyethylene terephthalate and whose sheath is polyethylene, and the mass ratio of the core to the sheath is core: sheath = 50: 50. The fineness was 2.2 dtex and the fiber length was 51 mm. The composition and adhesion amount of the fiber treatment agent applied to each fiber are as shown in the table. Except this, it carried out similarly to Example 1, and obtained the air through nonwoven fabric of 2 layer structure.

[Examples 5 and 6]
In this example, heat-extensible fibers having heat-fusibility were used as the constituent fibers of the nonwoven fabric. The fineness of this heat-extensible fiber is as shown in Table 1. Moreover, the composition and the amount of adhesion of the fiber treatment agent applied to the fibers are as shown in the same table. Except this, an air-through nonwoven fabric having a single layer structure was obtained in the same manner as in Example 1. The heat-extensible fiber shown in the table is a concentric core-sheath type composite fiber whose core is polyethylene terephthalate and whose sheath is polyethylene, and the mass ratio of the core to the sheath is core: sheath = 50: 50. The fiber length was 51 mm at a fineness of 3.3 dtex.

[Comparative Example 1]
A nonwoven fabric specimen was manufactured by the method for manufacturing a nonwoven fabric disclosed in JP-A-2008-002034.

[Comparative Example 2]
A nonwoven fabric test body was manufactured by the method for manufacturing a nonwoven fabric of Example 1 disclosed in Patent Document 1 described above.

[Evaluation]
Absorbent articles were manufactured using the obtained nonwoven fabric. The surface sheet was removed from a commercially available baby diaper (trade name “Merry's Sarah Air-Through M Size” manufactured by Kao Corporation) manufactured by Kao Corporation to obtain an absorbent body of this absorbent article. Instead, the air-through nonwoven fabric obtained above was used as the surface sheet. This air-through nonwoven fabric was incorporated into an absorbent article such that the surface on the first protrusion side became a skin facing surface and the surface on the second protrusion side opposed to the absorbent body. About the absorbent article obtained in this way, the liquid return amount and the liquid absorption time were measured by the following methods. These results are shown in Table 1 below.

[Liquid return amount]
A load of 20 g / cm ² was evenly applied on the top sheet of the absorbent article. A cylinder with a cross-sectional area of 1000 mm ² was applied to the approximate center of the test body, and artificial urine was injected therefrom. Saline was used as the artificial urine. After injecting artificial urine three times by 40 g every 10 minutes, the load of 20 g / cm ² was removed. Next, a filter paper loaded with a load of 35 g / cm ² was placed on the top sheet and allowed to stand for 2 minutes. The mass change of the filter paper was measured, and the value was defined as the liquid return amount (g).

[Liquid absorption time]
The time (seconds) from the start of injection at the time of the third injection of artificial urine at the time of the liquid return amount measurement until the artificial urine was completely absorbed was defined as the liquid absorption time.

  As is apparent from the results shown in Table 1, it can be seen that the absorbent article using the nonwoven fabric of the present invention as the top sheet has a fast liquid absorption time and a small amount of returned liquid. In particular, as is clear from the comparison between Examples 1 and 2 and Examples 3 and 4, when the nonwoven fabric has a multilayer structure and thin fibers are used as constituent fibers of the second protrusion side rather than the first protrusion side. It can be seen that the liquid absorption time is further shortened and the liquid return amount is further decreased. In addition, as is clear from the comparison between Examples 1 and 2 and Examples 5 and 6, when heat-extensible fibers are used as the raw cotton of the nonwoven fabric, the liquid absorption time is further shortened and the liquid return amount is further decreased. I understand.

DESCRIPTION OF SYMBOLS 10 Nonwoven fabric 11 1st protrusion part 11T 1st protrusion part top part 11K Internal space 11H Opening part 12 2nd protrusion part 12T 2nd protrusion part top part 12K Internal space 12H Opening part 13 and 14 Wall part Z1 1st surface Z2 2nd surface

Claims (8)

Having a first surface and a second surface opposite to the first surface;
A non-woven fabric having a plurality of first protrusions protruding toward the first surface and having an internal space, and a plurality of second protrusions protruding toward the second surface and having an internal space,
The first protrusion has a wall portion of an annular structure between the top and the opening of the internal space,
The first and second protrusions are arranged alternately and continuously along two different directions intersecting each other when the nonwoven fabric is viewed in plan view,
The non-woven fabric includes fibers to which a fiber treatment agent is attached,
The nonwoven fabric in which the said fiber processing agent contains the following (A) component, (B) component, and (C) component.
(A) Polyorganosiloxane (B) Alkyl phosphate ester (C) Anionic surfactant represented by the following general formula (1)

(In the formula, Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond, R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)   The nonwoven fabric according to claim 1, wherein the hydrophilicity increases in the order of the first protrusion, the wall, and the second protrusion.   The nonwoven fabric according to claim 1 or 2, wherein the second surface side has a higher degree of hydrophilicity than the first surface side at the top of the first protrusion.   The nonwoven fabric as described in any one of Claims 1 thru | or 3 in which the fiber which exists in the 2nd surface side is thinner than the fiber which exists in the 1st surface side.   The nonwoven fabric as described in any one of Claims 1 thru | or 4 in which the said polyorganosiloxane is contained in the ratio of 1 to 30 mass% with respect to the total mass of the said fiber treatment agent.   The nonwoven fabric according to any one of claims 1 to 5, wherein the component (C) is a dialkylsulfonic acid or a salt thereof.   The nonwoven fabric as described in any one of Claims 1 thru | or 6 which uses the heat | fever extensible fiber as said component fiber.   In the absorbent article provided with the surface sheet, the back sheet, and the absorbent body disposed between both sheets, the nonwoven fabric according to any one of claims 1 to 7 is used as the surface sheet, and the first surface of the nonwoven fabric is used. Absorbent article arranged so as to face the skin of the wearer.

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