TWI727966B - Non-woven fabric, absorbent article with the same, and manufacturing method of non-woven fabric - Google Patents

Abstract

When the non-woven fabric (10) of the present invention passes 90 g of artificial urine at a speed of 5.0 g/s under no pressure, a first region (11) with different hydrophilicity of the constituent fibers is generated along the thickness direction (T) And the second area (12). The first area (11) is an area including the surface of the nonwoven fabric (10), and the second area (12) is an area adjacent to the first area (11) when viewed in the thickness direction (T) of the nonwoven fabric (10). When the hydrophilicity is expressed by the contact angle with water, the contact angle of the constituent fibers in the first region (11) is greater than the contact angle of the constituent fibers in the second region (12).

Description

Non-woven fabric, absorbent article with the same, and manufacturing method of non-woven fabric

The present invention relates to a non-woven fabric and absorbent articles provided with the non-woven fabric.

In various absorbent articles represented by disposable diapers or menstrual sanitary napkins, the body fluid excreted by the wearer is absorbed and retained by the absorbent, and the retained body fluid is required to not seep back to the wearer's body side. The phenomenon of the body fluid retained in the absorbent body is usually called wet-back, and various solutions have been proposed to prevent this phenomenon. As a method for preventing the occurrence of dehumidification, there is known a method of controlling the hydrophilicity of the surface sheet as a member located on the skin facing side of the absorber, that is, the degree of affinity with water.

For example, Patent Document 1 describes that the surface sheet of an absorbent article has two layers, namely, the upper layer on the liquid-receiving side surface and the lower layer on the absorbent body side. The upper layer and the lower layer are formed of continuous filaments, and the hydrophilicity of the lower layer is higher than upper layer. Patent Document 2 describes a surface sheet of an absorbent article in which recesses and protrusions are formed alternately adjacent to each other by providing embossing in a specific pattern. The concave portion has hydrophilicity, while the convex portion has hydrophobicity, and the concave portion becomes a high-density area with a relatively high fiber density, and at the same time the convex portion becomes a low-density area with a relatively low fiber density. This document describes that according to the surface sheet, the concave portion has hydrophilicity instead of providing openings to increase the water absorption. Therefore, even if the body fluid absorbed by the absorber is subjected to pressure afterwards, it is possible to prevent back seepage.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2002-65738

Patent Document 2: Japanese Patent Laid-Open No. 2009-268559

The technologies up to now, including those described in Patent Documents 1 and 2, have focused on the hydrophilicity of the surface sheet in the state before the passage of body fluids to prevent the occurrence of dehumidification. However, the body fluid excreted to the absorbent article is not limited to one time, and multiple excretion occurs with prolonged wear. In addition, treatment agents such as hydrophilizing agents applied to the surface sheet will flow out with body fluids every time it is excreted, so the hydrophilicity of the surface sheet will change accordingly. There is no research focusing on this change to prevent the occurrence of anti-humidity. The present invention provides a non-woven fabric, which when 90 g of artificial urine is passed at a speed of 5.0 g/s under non-pressurized conditions, a first region and a second region with different hydrophilicity of constituent fibers are generated along the thickness direction The first area is the area including the surface of the non-woven fabric, and the second area is the area adjacent to the first area when viewed in the thickness direction of the non-woven fabric. When the above-mentioned hydrophilicity is expressed by the contact angle with water, the first area The contact angle of the constituent fibers of the region is greater than the contact angle of the constituent fibers of the second region. In addition, the present invention provides an absorbent article provided with the non-woven fabric described above, and the first region of the non-woven fabric is arranged to face the wearer's skin.

The present invention relates to an improvement of a non-woven fabric and an absorbent article provided with the non-woven fabric. More specifically, it relates to a non-woven fabric capable of maintaining control of liquid permeability even after a plurality of passes through the liquid, and an absorbent article provided with the non-woven fabric. The inventors of the present invention have made diligent research and found that when liquid is allowed to pass through two or more non-woven fabrics with different hydrophilicity in the thickness direction, the layer located on the liquid-receiving side, that is, the area on the upper layer side, and the area located on the absorber side The layer, that is, the area on the lower layer side is all hydrophobic, and compared with the area on the upper layer side, the area on the lower layer side is more hydrophobized. Hereinafter, the present invention will be described based on its preferred embodiments with reference to the drawings. Fig. 1 shows a cross-sectional view in the thickness direction showing an embodiment of the nonwoven fabric of the present invention. The non-woven fabric 10 shown in the figure includes a laminated structure including a first non-woven fabric layer 11 and a second non-woven fabric layer 12. In the non-woven fabric 10, the first non-woven fabric layer 11 and the second non-woven fabric layer 12 are partially joined to form a plurality of joined portions 13. The first non-woven fabric layer 11 protrudes in a direction away from the second non-woven fabric layer 12 at locations other than the joining portion 13. Thereby, a plurality of convex portions 14 are formed on the non-woven fabric 10. A space 16 defined by the first non-woven fabric layer 11 and the second non-woven fabric layer 12 is formed inside the convex portion 14. A recessed portion 15 is formed between adjacent convex portions 14, and the aforementioned joint portion 13 is located in the recessed portion 15. As a result, the nonwoven fabric 10 has an uneven structure on the surface of the first nonwoven fabric layer 11. On the other hand, the surface of the second non-woven fabric layer 12 of the non-woven fabric 10 becomes a substantially flat state. Fig. 1 is a view obtained by observing the non-woven fabric 10 in the thickness direction. As shown in Fig. 2(a), the convex portions 14 of the non-woven fabric 10 may be arranged in a scattered dot shape. Specifically, in the nonwoven fabric 10, the convex parts 14 and the concave parts 15 are alternately arranged along one direction X in the surface. In addition, the convex portions 14 and the concave portions 15 are alternately arranged in the Y direction orthogonal to the X direction. The nonwoven fabric of such a structure can be manufactured by, for example, the method described in Japanese Patent Laid-Open No. 2004-174234. The structure shown in Figure 2(b) can also be used instead of the structure shown in Figure 2(a). The non-woven fabric 10 shown in Fig. 2(b) has the following structure: convex portions 14 extending in one of the directions X in the surface thereof, and concave portions 15 extending in the same direction in the X direction are alternately arranged in the Y direction orthogonal to the X direction . In the embodiments of (a) and (b) of FIG. 2, a space 16 is formed inside the convex portion 14. One of the characteristics of the non-woven fabric 10 is that after the artificial urine is passed through the non-woven fabric 10, the state of the hydrophilicity in the thickness direction T of the non-woven fabric 10 is different. Specifically, when the non-woven fabric 10 passes artificial urine therethrough, a first region and a second region in which the hydrophilicity of the constituent fibers are different from each other is generated along the thickness direction T. The first area is an area including the surface of the non-woven fabric 10. On the other hand, the second region is a region adjacent to the first region when viewed in the thickness direction T of the nonwoven fabric 10. The so-called "adjacent" refers to the state where there is no other area between the two areas under observation and the two areas are in direct contact. In addition, the adjacency mentioned here also includes the following situations: Although there is a space between the two regions, when the non-woven fabric 10 is used, for example, the non-woven fabric 10 is incorporated into an absorbent article and worn on the absorbent article When (during liquid flood back), the space is squashed and the two areas are in direct contact. In the non-woven fabric 10, the first non-woven fabric layer 11 becomes an area corresponding to the first area. In addition, the second nonwoven fabric layer 12 becomes an area corresponding to the second area. Regarding the first non-woven fabric layer 11 and the second non-woven fabric layer 12, after the artificial urine is passed through the non-woven fabric 10, the hydrophilic properties of the constituent fibers become different from each other. The so-called hydrophilicity is the nature of the affinity with water. The so-called high hydrophilicity means that it is easily compatible with water. Fibers with high hydrophilicity can easily wet and diffuse water on their surface. The so-called low hydrophilicity means that the affinity with water is not good, and the fiber with low hydrophilicity is not easy to get water on its surface. In the present invention, the degree of hydrophilicity of the fiber is quantitatively expressed by the contact angle with water. The contact angle with water is measured by the following method. "Lower hydrophilicity" is synonymous with "larger contact angle", and "higher hydrophilicity" is synonymous with "smaller contact angle". Furthermore, in the nonwoven fabric 10, the contact angle of the constituent fibers of the first nonwoven fabric layer 11 as the first region is larger than the contact angle of the constituent fibers of the second nonwoven fabric layer 12 as the second region in the state after the liquid is passed through. That is, the first non-woven fabric layer 11 has a lower hydrophilicity than the second non-woven fabric layer 12 in the state after the liquid is passed through. As a result, when observing the entire non-woven fabric 10 after passing the liquid, a gradient of hydrophilicity of the constituent fibers from the first non-woven fabric layer 11 to the second non-woven fabric layer 12 is formed along the thickness direction T. In this way, the non-woven fabric 10 maintains the control of the liquid permeability even after a plurality of passes of the liquid. Especially by forming a hydrophilic gradient along the thickness direction T of the non-woven fabric 10, the non-woven fabric 10 is used as the surface sheet of the absorbent article and the first non-woven fabric layer in the non-woven fabric 10 is arranged in a manner facing the wearer's skin Among the absorbent articles of 11, the non-woven fabric 10 with a hydrophilic gradient effectively prevents the liquid temporarily absorbed and retained by the absorbent body from dehumidifying. In contrast to the non-woven fabric of the present invention, the inventors of the present invention discovered for the first time that the previous non-woven fabric having two or more layers of different hydrophilicity in the thickness direction is different from that on the upper layer side when liquids such as artificial urine are allowed to pass through the non-woven fabric. Compared with the area, the area on the lower layer side is more hydrophobic. Therefore, if this previous non-woven fabric is used as a surface sheet of an absorbent article, for example, the hydrophilicity of the part close to the surface is higher, thus forming a hydrophilic gradient in which the liquid moves from the absorbent body side to the surface side of the surface sheet. , The liquid temporarily absorbed and retained by the absorber is prone to dehumidification. The aforementioned so-called artificial urine permeation means that 90 g of artificial urine is passed through the non-woven fabric 10 at a speed of 5.0 g/s under the condition of no pressure when the non-woven fabric 10 is placed on the absorbent body. The supply of artificial urine to the non-woven fabric 10 is performed by using a silicon tube to guide the liquid ejection port to the upper side of the non-woven fabric placed on the absorbent body 10 mm away from the non-woven fabric, using a liquid injection pump (manufactured by ISMATEC, MCP-J). The absorption system is the Merries (registered trademark) tape type S size removal surface sheet manufactured by Kao Co., Ltd. in 2013, and its absorber is used. The supply of 90 g is assumed to be the average excretion of infants and young children. In addition, the supply rate of 5.0 g/s is assumed to be the rate of urine excretion in infants and young children. The composition of artificial urine is as follows: urea 1.940% by mass, sodium chloride 0.795% by mass, magnesium sulfate 0.110% by mass, calcium chloride 0.062% by mass, potassium sulfate 0.197% by mass, red No. 2 (dye) 0.010% by mass, water ( About 96.88% by mass) and polyoxyethylene lauryl ether (about 0.07% by mass), and the surface tension was adjusted to 53±1 dyne/cm (23°C). The method for measuring the contact angle with water is as follows. After passing the artificial urine through the non-woven fabric 10 under the above conditions, fibers were taken out from the first non-woven fabric layer 11 and the second non-woven fabric layer 12 in the non-woven fabric 10, and the contact angle of the fibers with water was measured. Furthermore, the present inventors confirmed that no change in the contact angle was observed within about half a day after the passage of artificial urine. In the Examples and Comparative Examples, the contact angle after the passage was obtained by measuring within half a day. As the measuring device, the automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. was used. The contact angle is measured using distilled water. The amount of liquid ejected from an inkjet water droplet ejection unit (Cluster Technology, a pulse jet CTC-25 with an aperture of 25 μm) was set to 20 microliters, and water droplets were dropped from directly above the fiber. Record the dripping situation to a high-speed recording device connected to a horizontally set camera. From the point of view of subsequent image analysis, the camera is preferably a personal computer equipped with a high-speed capture device. In this measurement, images are taken every 17 msec. In the recorded image, the first image after the water droplets fall onto the fibers from the first non-woven layer 11 and the second non-woven layer 12 uses the attached software FAMAS (software version is set to 2.6.2, and the analysis method is set to For the droplet method, the analysis method is set to the θ/2 method, the image processing algorithm is set to no reflection, the image processing image mode is set to frame, the limit level is set to 200, and curvature correction is not performed) for image analysis, Calculate the angle formed by the surface of the water droplet in contact with the air and the fiber, and set it as the contact angle. The fibers taken from the first non-woven fabric layer 11 and the second non-woven fabric layer 12 were cut to a fiber length of 1 mm, and the fibers were placed on the sample table of the contact angle meter and kept horizontal. The contact angles of two different parts of the fiber were measured. Measure the contact angle of N=5, accurate to one decimal place, and define the average value of the measured values of a total of 10 points (rounded to one decimal place) as the contact angle. In order to control the hydrophilicity of the non-woven fabric 10 after the artificial urine is passed through as described above, it is preferable to apply a fiber treatment agent to the fibers constituting the first non-woven fabric layer 11 and the second non-woven fabric layer 12 in advance. The so-called fiber treatment agent is a substance that can adhere to the surface of the fiber to change the hydrophilicity of the fiber. Generally, a surfactant is preferably used. It is particularly preferable to apply a method such that the contact angle of the constituent fibers of the first non-woven fabric layer 11 is greater than the contact angle of the constituent fibers of the second non-woven fabric layer 12 before the artificial urine is passed through. Fiber treatment agent. Thereby, the non-woven fabric 10 has formed a hydrophilic gradient along the thickness direction T of the non-woven fabric 10 before the liquid is passed, and the hydrophilic gradient is maintained after the liquid is passed. As a result, when the non-woven fabric 10 is used as a surface sheet of an absorbent article, the occurrence of dehumidification can be more effectively prevented. The relative hydrophilicity of the first non-woven fabric layer 11 and the second non-woven fabric layer 12 is as described above. The contact angle of the constituent fibers of the first non-woven fabric layer 11 is preferably 80 degrees or more after the liquid is passed through. Preferably it is 85 degrees or more, More preferably, it is 90 degrees or more. Furthermore, it is preferably 100 degrees or less, more preferably 97 degrees or less, and still more preferably 94 degrees or less. The contact angle of the constituent fibers of the first non-woven fabric layer 11 is preferably 80 degrees or more and 100 degrees or less after passing the liquid, more preferably 85 degrees or more and 97 degrees or less, and still more preferably 90 degrees or more and 94 degrees or less. On the other hand, the contact angle of the constituent fibers of the second non-woven fabric layer 12 is set to be smaller than the contact angle of the constituent fibers of the first non-woven fabric layer 11. It is preferably 65 degrees or more, more preferably 70 degrees or more after the liquid is passed. , More preferably 75 degrees or more. Furthermore, it is preferably 90 degrees or less, more preferably 87 degrees or less, and still more preferably 84 degrees or less. The contact angle of the constituent fibers of the second non-woven fabric layer 12 is preferably 65 degrees or more and 90 degrees or less after passing the liquid, more preferably 70 degrees or more and 87 degrees or less, and still more preferably 75 degrees or more and 84 degrees or less. From the viewpoint of reducing the amount of dehumidification and preventing the liquid from seeping back to the user, after the liquid is passed, the contact angle of the constituent fibers of the first non-woven fabric layer 11 as the first area and the second non-woven fabric layer 12 as the second area The difference (the former-the latter) of the contact angles of the constituent fibers is preferably greater than 0 degrees, more preferably greater than 3 degrees, and still more preferably greater than 5 degrees. Basically, the larger the difference in contact angle, the better, but in order to allow the liquid to penetrate the first non-woven fabric layer 11 quickly, it is preferable to suppress the hydrophilicity to a certain extent, and to control the mobility of the liquid from the second non-woven fabric layer 12 to the absorber. , Preferably has a certain degree of hydrophobicity, so the upper limit of the contact angle difference is preferably 30 degrees or less, more preferably 25 degrees or less, and even more preferably 20 degrees or less. The contact angles of the constituent fibers of the first and second non-woven fabric layers 11 and 12 after the liquid flow are described above. The contact angles of the constituent fibers of the first and second non-woven fabric layers 11 and 12 before the liquid flow are preferably as follows Said. That is, the contact angle of the constituent fibers of the first non-woven fabric layer 11 is preferably 75 degrees or more, more preferably 78 degrees or more, and still more preferably 81 degrees or more before the liquid is passed. Moreover, it is preferably less than 90 degrees, more preferably 87 degrees or less, and still more preferably 84 degrees or less. The contact angle of the constituent fibers of the first non-woven fabric layer 11 is preferably 75 degrees or more and less than 90 degrees before passing the liquid, more preferably 78 degrees or more and 87 degrees or less, and still more preferably 81 degrees or more and 84 degrees or less. The contact angle of the constituent fibers of the first non-woven fabric layer 11 before the liquid is preferably smaller than the contact angle of the constituent fibers of the first non-woven fabric layer 11 after the liquid is passed. On the other hand, the contact angle of the constituent fibers of the second non-woven fabric layer 12 is conditioned to be smaller than the contact angle of the constituent fibers of the first non-woven fabric layer 11. It is preferably 60 degrees or more, more preferably 65 degrees or more before passing the liquid. Preferably it is 70 degrees or more. Furthermore, it is preferably 85 degrees or less, more preferably 80 degrees or less, and still more preferably 75 degrees or less. The contact angle of the constituent fibers of the second non-woven fabric layer 12 is preferably 60 degrees or more and 85 degrees or less before passing the liquid, more preferably 65 degrees or more and 80 degrees or less, and still more preferably 70 degrees or more and 75 degrees or less. From the viewpoint of reducing the amount of dehumidification and preventing the liquid from seeping back to the user, before the liquid is passed, the contact angle of the constituent fibers of the first non-woven fabric layer 11 as the first area and the second non-woven fabric layer as the second area The difference in contact angle of the constituent fibers of 12 (the former-the latter) is preferably greater than 0 degrees, more preferably greater than 3 degrees, and still more preferably greater than 5 degrees. Basically, the larger the difference in contact angle, the better. However, if the first non-woven fabric layer 11 is hydrophobized too much, it may hinder the passage of liquid. In addition, if the second non-woven fabric layer 12 is strongly hydrophilized, there is excessive liquid retention. It is high and hinders liquid mobility to the absorber, so the upper limit of the difference in contact angle is preferably 30 degrees or less, more preferably 25 degrees or less, and still more preferably 20 degrees or less.

In order to control the degree of hydrophilicity of each nonwoven fabric layer 11, 12 as described above, it is important to appropriately select the type of fiber treatment agent applied to each nonwoven fabric layer 11, 12. It is particularly preferable to make the main component of the fiber treatment agent applied to the constituent fibers of the first area different from the main component of the fiber treatment agent applied to the constituent fibers of the second area. The so-called "main component" refers to a component of the fiber treatment agent in the state before being applied to the fiber, and the content ratio of the total component of the fiber treatment agent is 10% by mass or more. The adhesion amount of the fiber treatment agent to the fiber is generally 2% by mass or less. The reason for setting the adhesion amount so low is that if an excessive amount is given, it will contaminate the manufacturing machinery or make the user's skin feel sticky. Therefore, in the above-mentioned fiber treatment agent that is only used in a very small amount, if the ratio of the main component in the fiber treatment agent is not set to 10% by mass or more, the function of hydrophilicity and the like on the non-woven fabric is insufficient. For example, when the ratio of the main component is 10% by mass, the ratio of the main component added to the fiber is only 0.2% by mass relative to the fiber. Therefore, there are also cases where there are more than two main components. When there are two or more main components, it is preferable to make the main components in the first non-woven fabric layer 11 and the second non-woven fabric layer 12 be different regardless of which main component is focused on. As long as the main components are different, the type of the minor component in the fiber treatment agent applied to the constituent fibers of the first nonwoven fabric layer 11 and the minor component in the fiber treatment agent applied to the constituent fibers of the second nonwoven fabric layer 12 does not matter.

The main component of the fiber treatment agent applied to the constituent fibers of the first non-woven fabric layer 11 (the first region) (hereinafter also referred to as the "first region main component") and the second non-woven fabric layer 12 (second region) When the main components of the fiber treatment agent applied to the fibers are different (hereinafter also referred to as the "second region main components"), it is preferable that the two main components have different elution degrees in water when they are in contact with water. It is particularly preferable that the degree of dissolution of the main component in the first region in water is greater than that of the main component in the second region. By using the main component of the first region and the main component of the second region with such properties, the second non-woven fabric layer 12 maintains a higher hydrophilicity than the first non-woven fabric layer 11 after repeated liquid passes, effectively preventing dehumidification. From the viewpoint of more effective prevention of re-wetting, it is advantageous to apply to the constituent fibers of the second non-woven fabric layer 12 (the second region), preferably 40% by mass or more, more preferably 50% by mass or more, which is different from the second non-woven fabric layer 12 (second region). 1 The non-woven fabric layer 11 (the first region) constitutes the main component of the main component applied by the fiber. In particular, regarding the second non-woven fabric layer 12, it is preferable that one of the main components of the fiber treatment agent applied to the constituent fibers is polyorganosiloxane having a hydrophilic group. The reason is that it can maintain a high level even after passing the liquid. The hydrophilicity of the constituent fibers in the first non-woven fabric layer 11. Examples of the hydrophilic group include a hydroxyl group, a polyoxyalkylene group, an amino group, a diamine group, a polyglyceryl group, an epoxy group, a methanol group, a carboxyl group, a glycol group, and a methacryl group. These hydrophilic groups can be used alone or in combination of two or more kinds. Among the above-mentioned hydrophilic groups, it is preferable to use polyoxyalkylene groups or polyoxyalkylene groups from the viewpoint of imparting sufficient hydrophilicity to the fiber surface and improving the dispersibility in water to improve the handleability as a fiber treatment agent. Glyceryl. Particularly preferred is polyoxyalkylene-modified polyoxyalkylene-modified polysiloxane. The reason is that even after the liquid is passed through, the hydrophilicity of the constituent fibers of the first non-woven fabric layer 11 can be maintained ( That is, the contact angle can be kept small). Polyoxyalkylene modified polysiloxane is a polymer compound made by modifying polysiloxane with polyoxyalkylene. As the polyoxyalkylene used for modification, it is preferable to use a lower alkylene having a carbon number of 2 or more and 4 or less. As a specific example, polyoxyethylene (hereinafter also referred to as "POE") ) Or polyoxypropylene (hereinafter also referred to as "POP"), polyoxybutylene (hereinafter also referred to as "POB"). In addition, polyoxyalkylene groups including multiple types of POE, POP, and POB can also be used. The number of repetitions of the oxyalkylene group in the polyoxyalkylene group is preferably 3 or more, more preferably 5 or more, and still more preferably 7 or more. Moreover, it is preferably 40 or less, more preferably 30 or less, and still more preferably 20 or less. The number of repeating oxyalkylene groups is preferably 3 or more and 40 or less, more preferably 5 or more and 30 or less, and still more preferably 7 or more and 20 or less. As the polyoxyalkylene-modified polysiloxane, commercially available products can also be used. Examples of such commercially available products include "Shin-Etsu Silicones KF-6012" and "Shin-Etsu Silicones X-22-4515" manufactured by Shin-Etsu Chemical Co., Ltd. The ratio of the polyoxyalkylene-modified polysiloxane contained in the fiber treatment agent applied to the constituent fibers of the second nonwoven fabric layer 12 is preferably 15% by mass or more, more preferably 20% by mass or more, and still more preferably It is 25% by mass or more. Furthermore, it is preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less. The ratio of the polyoxyalkylene-modified polysiloxane contained in the fiber treatment agent is preferably 15% by mass or more and 60% by mass or less, more preferably 20% by mass or more and 50% by mass or less, and more preferably 25% by mass % Or more and 40% by mass or less. Examples of substances used as main components other than the above-mentioned polyoxyalkylene-modified polysiloxane include: alkali metal salts of alkyl phosphates, POE polyol fatty acid esters, alkyl betaines, and alkyl sulfonates Acid, alkyl sulfuric acid, dialkyl sulfonic acid, POE alkyl amide, etc. Examples of minor components that are not the main component include alkylhydroxysulfobetaine, imidazolium-type cationic surfactants, polyethylene glycol, polypropylene glycol, and the like. Regarding the fiber treatment agent applied to the constituent fibers of the first non-woven fabric layer 11, it is easier to make the hydrophilicity of the constituent fibers of the first and second non-woven fabric layers 11 and 12 after the liquid pass is different from each other. It is preferable to contain a hydrophobic substance as a main component. In detail, the main component of the fiber treatment agent is preferably selected from hydrocarbon oils, fluorine oils, fatty acid esters, polyoxyalkylene modified polysiloxanes, polyorganosiloxanes, and alkanes having a carbon number of 16 or more. At least one of the group consisting of nonionic and ionic surfactants. Among these substances, it is particularly preferable to use a nonionic and ionic surfactant selected from the group consisting of polyoxyalkylene-modified polysiloxane, polyorganosiloxane, and an alkyl group with a carbon number of 16 or more. At least one of the group, and more preferably at least one selected from the group consisting of polyorganosiloxane, nonionic and ionic surfactants having an alkyl group with 16 or more carbon atoms. Among the fiber treatment agents applied to the constituent fibers of the first non-woven fabric layer 11, minor components that are not the main components include, for example, alkyl sulfonic acid, alkyl sulfuric acid, dialkyl sulfonic acid, and alkyl hydroxy sulfonate. Betaine, imidazolium type cationic surfactants, polyethylene glycol, polypropylene glycol, etc. The identification and quantification of the type of the fiber treatment agent in the nonwoven fabric to which the fiber treatment agent is applied can be performed, for example, by the method described below. When the non-woven fabric is the surface sheet of an absorbent article, collect the product of the required amount for measurement, peel the surface sheet of the product from the absorbent body, and use a solvent such as methanol or ethanol to extract from the peeled surface sheet Fiber treatment agent. After the fiber treatment agent is extracted, the residue is separated by column, GPC (Gel Permeation Chromatography), GC-MS (Gas Chromatography-Mass Spectrometry), LC-MS (Liquid Chromatography-Mass Spectrometry), NMR (Nuclear Magnetic Resonance, Nuclear Magnetic Resonance), IR (infrared radiation), solvent extraction using solubility in solvents, or mixing Solvent recrystallization and element analysis are used to identify and quantify the structure of the substance. A component containing 10% by mass or more with respect to the total amount becomes the above-mentioned main component. When the fiber treatment agent is applied to the first non-woven fabric layer 11 and the second non-woven fabric layer 12, for example, there are cases where the fiber treatment agent is applied to the fibers before the non-woven fabric, and the fiber treatment agent is applied to the non-woven fabric after the non-woven fabric is formed. Specific methods for applying the fiber treatment agent include, for example, immersing the fiber or non-woven fabric in the fiber treatment agent, spraying the fiber or non-woven fabric with the fiber treatment agent, using various rollers such as touch rollers to mechanically coat the fiber or non-woven fabric, Coating of various printing methods such as inkjet, gravure, screen, and flexible printing. After the fiber treatment agent is applied, the excess amount of the fiber treatment agent is removed, and then the volatile components are removed by heating or natural drying, thereby allowing the fiber treatment agent to adhere to the surface of the fiber. Fig. 3 shows another embodiment of the non-woven fabric of the present invention. The nonwoven fabric 10 shown in this figure also has the laminated structure of the 1st nonwoven fabric layer 11 and the 2nd nonwoven fabric layer 12 like the nonwoven fabric of the embodiment shown in FIG. However, the non-woven fabric 10 of this embodiment is the non-woven fabric of the embodiment shown in FIG. 1, no space is formed inside the convex portion 14, and the inside of the convex portion 14 is filled with fibers. In addition, in the concave portion 15 located between the adjacent convex portions 14, the surface of the second non-woven fabric layer 12 is exposed. The nonwoven fabric 10 of the embodiment shown in FIG. 4 also has the laminated structure of the 1st nonwoven fabric layer 11 and the 2nd nonwoven fabric layer 12 like the nonwoven fabric demonstrated so far. However, the nonwoven fabric 10 of this embodiment has substantially flat surfaces, and does not have an uneven structure. In order to ensure the liquid permeability of the entire non-woven fabric 10, it is preferable that the two non-woven fabric layers 11, 12 are discontinuously joined over the entire area of the opposing surfaces thereof. The non-woven fabric 10 of this embodiment has no difference in appearance between the front and the back. Therefore, it is determined which side of the non-woven fabric layer belongs to the first non-woven fabric layer 11 according to the size of the contact angle of the constituent fibers in the non-woven fabric 10 after the liquid is passed. Specifically, the non-woven fabric layer where the fiber with the larger contact angle is located belongs to the first non-woven fabric layer 11. The non-woven fabric 10 of the embodiment shown in FIG. 5 is different from the non-woven fabric of the above embodiment in that it is a single layer. In the non-woven fabric 10, after passing artificial urine through the non-woven fabric 10, a first region 11A and a second region 12A of which the hydrophilicity of the constituent fibers are different from each other are generated in the thickness direction T. The first area 11A is an area including one surface of the non-woven fabric 10. The second region 12A is a region adjacent to the first region 11A when viewed in the thickness direction T of the nonwoven fabric 10. In the nonwoven fabric 10, after the liquid is passed, the contact angle of the constituent fibers in the first region 11A becomes larger than the contact angle of the constituent fibers in the second region 12A. As a result, when observing the entire nonwoven fabric 10 after passing the liquid, a gradient of the hydrophilicity of the constituent fibers in which the hydrophilicity of the constituent fibers increases from the first region 11A to the second region 12A is formed along the thickness direction T. In the nonwoven fabric 10 of this embodiment, which side belongs to the first region 11A is judged in the same manner as in the case of the embodiment shown in FIG. 4. When manufacturing the non-woven fabric 10 of this embodiment, for example, a first fiber treatment agent may be applied from one side of the non-woven fabric, and a second fiber treatment agent having a composition different from the first fiber treatment agent may be applied from the other side. As another method, a first fiber web containing fibers applied with a first fiber treatment agent and a second fiber web containing fibers applied with a second fiber treatment agent different in composition from the first fiber treatment agent are laminated, and then The laminated fiber web can be made into a non-woven fabric. Or apply a first fiber treatment agent to the first fiber web, and apply a second fiber treatment agent with a composition different from the first fiber treatment agent to the second fiber web, and then layer the two fiber webs, and then make the laminated fiber web non-woven That's it. As the resin constituting the fibers of the non-woven fabric in each of the above embodiments, various thermoplastic resins having fiber-forming properties can be used. Examples of such resins include polyolefin resins such as polyethylene (PE) or polypropylene, polyester resins such as polyethylene terephthalate (PET) or polybutylene terephthalate, Vinyl resins such as polystyrene or polyvinyl chloride, polyacrylic or polymethacrylic resins containing polyacrylic acid, polymethacrylic acid, or esters of these, and the like. These resins may be used individually by 1 type, and may be used in combination of 2 or more types. When two or more resins are used in combination, it includes a blend of two or more resins to produce a single-structure fiber, and a composite structure such as a core-sheath type or side by side type fiber. The condition of the fiber. For example, when the laminated fiber web is subjected to hot-air treatment to make it nonwoven to produce the non-woven fabric 10 of this embodiment, from the viewpoint of hot-air treatment conditions and the physical properties of the non-woven fabric, it is preferable to use polyester resin for the core and The sheath uses a core-sheath composite structure fiber made of polyolefin resin with a lower melting point than the core. In the embodiment shown in FIGS. 1 to 4, the types of the constituent fibers of the first non-woven fabric layer 11 and the second non-woven fabric layer 12 may be the same or different. The same applies to the basis weight, and the basis weights of the first non-woven fabric layer 11 and the second non-woven fabric layer 12 may be the same or different. According to the present invention, there is also provided an absorbent article provided with the non-woven fabric described so far. In the absorbent article, it is preferable to arrange the first non-woven fabric layer 11 (the first region 11A) of the non-woven fabric so as to face the wearer's skin in terms of preventing the occurrence of rewetting. That is, the nonwoven fabric is preferably used as a surface sheet of absorbent articles. Absorbent articles are generally composed of a liquid-permeable surface sheet, a liquid-retaining absorber, and a liquid-impermeable or poorly-permeable back sheet. As the absorber, a mixed fiber stack of flap pulp and a water-absorbent polymer, or an absorbent sheet in which a water-absorbent polymer is interposed between a pair of pulp sheets can be used. As the back sheet, a film made of synthetic resin, a film obtained by imparting moisture permeability, a non-woven fabric with impermeable liquid permeability, or the like can be used. The absorbent article can further include various members according to the specific use of the absorbent article. Such components are well known by the industry. For example, when the absorbent article is applied to disposable diapers or menstrual sanitary napkins, one or more pairs of three-dimensional protections can be arranged on the left and right sides of the surface sheet. The non-woven fabric of the present invention utilizes the gradient of hydrophilicity generated after the liquid is passed, and in addition to the above-mentioned surface sheet for absorbent articles, it can also be used as a secondary sheet for absorbent articles. The secondary sheet is generally a liquid-permeable sheet arranged between the surface sheet of the absorbent article and the absorbent body. The present invention has been described above based on its preferred embodiments, but the present invention is not limited to the above-mentioned embodiments. For example, in the embodiment shown in FIGS. 1 to 4, the non-woven fabric 10 is a double-layer structure of the first non-woven fabric layer 11 and the second non-woven fabric layer 12. It can also be used on the outer surface of the second non-woven fabric layer 12 instead of the double-layer structure. Furthermore, one layer or two or more other non-woven fabric layers are laminated. Similarly, in the embodiment shown in FIG. 5, one or two or more other non-woven fabric layers can be laminated on the outer surface of the second region 12A. Regarding the above-mentioned embodiment, the present invention further discloses the following non-woven fabrics and absorbent articles. ＜1＞ A non-woven fabric, when 90 g of artificial urine is passed at a speed of 5.0 g/s under no pressure, the first and second regions of the fibers are formed along the thickness direction, and the hydrophilicity of the constituent fibers is different from each other. The first area is the area including the surface of the non-woven fabric, and the second area is the area adjacent to the first area when viewed in the thickness direction of the non-woven fabric. When the above-mentioned hydrophilicity is expressed by the contact angle with water, the first area The contact angle of the constituent fibers of the region is greater than the contact angle of the constituent fibers of the second region. <2> The non-woven fabric as described in the above <1>, in which a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and when the above fiber treatment agent has two or more main components, no matter what In the case of which principal component, the principal components in the first region and the second region are different. <3> The non-woven fabric described in the above <1> or <2>, in which a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the main component of the fiber treatment agent is applied to the constituent fibers of the first region It is different from the main component of the fiber treatment agent applied to the constituent fibers of the second region. <4> The nonwoven fabric described in any one of the above <1> to <3>, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the above fibers are applied to the constituent fibers of the second region The main component of the treatment agent is polyorganosiloxane with a hydrophilic group. <5> The non-woven fabric as described in the above <4>, wherein the hydrophilic group is a hydroxyl group, a polyoxyalkylene group, an amino group, a diamine group, a polyglycerol group, an epoxy group, a methanol group, a carboxyl group, a glycol group, or a methyl group. Acrylic acid group, or a combination of two or more of these. <6> The nonwoven fabric as described in the above <4> or <5>, wherein the hydrophilic group is a polyoxyalkylene group or a polyglycerin group. <7> The nonwoven fabric described in any one of the above <1> to <6>, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the fiber treatment agent is applied to the second region One of the main components is polyoxyalkylene modified polysiloxane. <8> The non-woven fabric as described in the above <7>, wherein the ratio of the polyoxyalkylene-modified polysiloxane contained in the fiber treatment agent applied to the constituent fibers of the second region is preferably 15% by mass or more , More preferably 20% by mass or more, still more preferably 25% by mass or more, more preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less. <9> The non-woven fabric as described in the above <8>, wherein the number of repetitions of the oxyalkylene group in the polyoxyalkylene group is preferably 3 or more, more preferably 5 or more, still more preferably 7 or more, and more preferably It is 40 or less, more preferably 30 or less, and still more preferably 20 or less. <10> The nonwoven fabric described in any one of the above <1> to <9>, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the fiber treatment agent is applied to the first region The main component is preferably nonionic and ionic selected from hydrocarbon oils, fluorine oils, fatty acid esters, polyoxyalkylene-modified polysiloxanes, polyorganosiloxanes, and alkyl groups with a carbon number of 16 or more At least one of the group consisting of surfactants. Among these substances, it is particularly preferable to use a polyoxyalkylene-modified polysiloxane, polyorganosiloxane, and an alkane having a carbon number of 16 or more. At least one of the group consisting of nonionic and ionic surfactants, and it is more preferable to use nonionic and ionic surfactants selected from polyorganosiloxanes and alkyl groups with a carbon number of 16 or more. At least one of the group consisting of. <11> The nonwoven fabric described in any one of the above <1> to <10>, which contains a laminated structure including a first nonwoven fabric layer and a second nonwoven fabric layer, and the first nonwoven fabric layer becomes a region corresponding to the first region, The second nonwoven fabric layer becomes an area corresponding to the second area. <12> The non-woven fabric described in any one of the above <1> to <11>, wherein the contact angle of the constituent fibers of the first region after the artificial urine is passed through is preferably 80 degrees or more, more preferably 85 degrees or more, more preferably 90 degrees or more, more preferably 100 degrees or less, more preferably 97 degrees or less, and still more preferably 94 degrees or less. <13> The nonwoven fabric described in any one of the above <1> to <12>, wherein the contact angle of the constituent fibers in the second region is set to be smaller than the contact angle of the constituent fibers in the first region as a condition for artificial urine After passing through the liquid, it is preferably 65 degrees or more, more preferably 70 degrees or more, more preferably 75 degrees or more, more preferably 90 degrees or less, more preferably 87 degrees or less, and still more preferably 84 degrees or less . <14> The non-woven fabric described in any one of the above <1> to <13>, after the artificial urine is passed through, the contact angle of the constituent fibers in the first region and the contact angle of the constituent fibers in the second region are The difference (the former-the latter) is preferably greater than 0 degrees, more preferably 3 degrees or more, more preferably 5 degrees or more, more preferably 30 degrees or less, more preferably 25 degrees or less, and still more preferably Below 20 degrees. <15> The non-woven fabric described in any one of the above <1> to <14>, wherein the contact angle of the constituent fibers of the first region before the artificial urine is passed is preferably 75 degrees or more, more preferably 78 degrees Above, it is more preferably 81 degrees or more, more preferably less than 90 degrees, more preferably 87 degrees or less, and still more preferably 84 degrees or less. <16> The non-woven fabric described in any one of the above <1> to <15>, wherein the contact angle of the constituent fibers in the second region is set to be smaller than the contact angle of the constituent fibers in the first region. Before passing the liquid, it is preferably 60 degrees or more, more preferably 65 degrees or more, still more preferably 70 degrees or more, more preferably 85 degrees or less, more preferably 80 degrees or less, and still more preferably 75 degrees or less. <17> The non-woven fabric described in any one of the above <1> to <16>, before the artificial urine is passed through, the contact angle of the constituent fibers in the first region is equal to the contact angle of the constituent fibers in the second region The difference (the former-the latter) is preferably greater than 0 degrees, more preferably 3 degrees or more, more preferably 5 degrees or more, more preferably 30 degrees or less, more preferably 25 degrees or less, and still more preferably Below 20 degrees. <18> The non-woven fabric described in any one of the above <1> to <17>, in the state before the artificial urine is passed, the contact angle of the constituent fibers in the first area is less than 90 degrees, which is used in the artificial urine In the state after the liquid is passed through, the contact angle of the constituent fibers in the first area is 90 degrees or more. <19> The non-woven fabric described in any one of the above <1> to <18>, in the state before the artificial urine is passed through, the contact angle of the constituent fibers in the first region is greater than that of the constituent fibers in the second region Contact angle. <20> The nonwoven fabric described in any one of the above <1> to <19> has an uneven structure on the surface of the first region. <21> The non-woven fabric described in the above <20>, which contains a laminated structure including a first non-woven fabric layer corresponding to the first region and a second non-woven fabric layer corresponding to the second region, the first non-woven fabric layer and the second non-woven fabric layer portion The first non-woven fabric layer protrudes away from the second non-woven fabric layer in the direction away from the second non-woven fabric layer to form a plurality of convex portions. The first non-woven fabric layer and the second non-woven fabric layer are formed inside the convex portions. The space delineated by the second non-woven layer. <22> The non-woven fabric described in any one of the above <1> to <21>, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the above fiber treatment agent is applied to the second region One of the main components is polyoxyalkylene-modified polysiloxane. The main components other than polyoxyalkylene-modified polysiloxane are alkali metal salts of alkyl phosphates and polyoxyethylene polyols. Fatty acid ester, alkyl betaine, alkyl sulfonic acid, alkyl sulfuric acid, dialkyl sulfonic acid, or polyoxyethylene alkyl amide. <23> An absorbent article comprising the non-woven fabric described in any one of the above <1> to <22>, and the first region in the non-woven fabric is arranged to face the wearer's skin. <24> The absorbent article as described in the above <23>, which uses the above-mentioned non-woven fabric as a surface sheet, and arranges the first region in the non-woven fabric so as to face the wearer's skin. <25> A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as described in any one of the above <1> to <22>, which has the following steps: Apply the first fiber treatment agent from one side of the non-woven fabric, and separate On one side, a second fiber treatment agent having a composition different from the first fiber treatment agent is applied, and the main components of the first fiber treatment agent and the second fiber treatment agent are different. <26> A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as described in any one of the above <1> to <22>, which has the following steps: The first fiber containing the fiber to which the first fiber treatment agent is applied The web is laminated with a second fiber web containing fibers applied with a second fiber treatment agent whose composition is different from the first fiber treatment agent, and the laminated fiber web is then non-woven, and the first fiber treatment agent and the second fiber treatment agent The main components are different. <27> A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as described in any one of the above <1> to <22>, which has the following steps: applying a first fiber treatment agent to the first fiber web, and applying a first fiber treatment agent to the first fiber web; 2 The second fiber treatment agent with a different composition from the first fiber treatment agent is applied to the fiber web, and then the two fiber webs are laminated, and then the laminated fiber web is non-woven, and the main components of the first fiber treatment agent and the second fiber treatment agent different. <28> The manufacturing method as described in any one of the above <25> to <27>, wherein the main components of the first fiber treatment agent and the second fiber treatment agent are different, and the first region adjacent in the thickness direction of the non-woven fabric and In the second area, the first fiber treatment agent is applied to the first area, and the second fiber treatment agent is applied to the second area. <29> The manufacturing method as described in any one of the above <25> to <28>, wherein one of the main components of the second fiber treatment agent is polyoxyalkylene-modified polysiloxane. <30> The manufacturing method described in the above <29>, wherein the ratio of the polyoxyalkylene-modified polysiloxane contained in the second fiber treatment agent is preferably 15% by mass or more, more preferably 20% by mass or more, It is more preferably 25% by mass or more, more preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less. <31> The manufacturing method described in any one of the above <25> to <30>, wherein the main component of the first fiber treatment agent is preferably selected from hydrocarbon oil, fluorine oil, fatty acid ester, and polyoxyalkylene At least one of the group consisting of modified polysiloxanes, polyorganosiloxanes, and nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more. Among these substances, particularly preferred To use at least one selected from the group consisting of polyoxyalkylene-modified polysiloxane, polyorganosiloxane, nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more, and more It is preferable to use at least one selected from the group consisting of polyorganosiloxanes and nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more. Examples Hereinafter, the present invention will be explained in more detail with examples. However, the scope of the present invention is not limited to these embodiments. Unless otherwise specified, "%" means "mass%". [Example 1] According to the method described in Japanese Patent Laid-Open No. 2004-174234, the nonwoven fabric 10 having the structure shown in Figs. 1 and 2(a) was manufactured. The first non-woven fabric layer 11 uses two types of constituent fibers (one is referred to as "fiber 1" and the other is referred to as "fiber 2"), and the second non-woven fabric layer 12 uses one type of constituent fiber. Both the first fiber and the second fiber are core-sheath fibers whose core is polyethylene terephthalate (PET) and sheath is polyethylene (PE). Fiber 1 has a fineness of 2.2 dtex, and fiber 2 is a core-sheath fiber. The fineness is 4.4 dtex. The constituent fibers used in the second non-woven fabric layer 12 are core-sheath fibers in which the core is polyethylene terephthalate (PET) and the sheath is polyethylene (PE), and the fineness is 2.2 dtex. The basis weights of the first non-woven fabric layer 11 and the second non-woven fabric layer 12 are both 18 g/m ² . The composition ratio of the fibers and the fiber treatment agent used in the fibers are shown in Table 1. Each non-woven fabric layer 11, 12 is composed of hot-air non-woven fabric. In order to prepare each of the non-woven fabric layers 11 and 12 before lamination, first, about 12 g of the fibers weighed were immersed in the fiber treatment agent shown in Table 1, and the fiber treatment agent was applied to the fiber. The adhesion amount of the fiber treatment agent is 0.40% with respect to the entire non-woven fabric. Then, the fiber is carded to form a fiber web, and the fiber web is subjected to hot air treatment, thereby obtaining non-woven fabrics 11 and 12. After that, the non-woven fabrics 11 and 12 are laminated, and while the non-woven fabric 11 is sucked into a convex shape by a roller with a suction function, the non-woven fabrics 11 and 12 are thermally welded to the joint 13 to form a concave-convex structure. In this way, the target non-woven fabric 10 is obtained. [Examples 2 to 8 and Comparative Examples 1 to 4] In Example 1, as the fiber treatment agent applied to the first nonwoven fabric layer 11 and the second nonwoven fabric layer 12, those shown in Table 1 were used. Except for this, the non-woven fabric 10 having the structure shown in Figs. 1 and 2(a) was obtained in the same manner as in Example 1. In Comparative Example 3 and Comparative Example 4, Moony (registered trademark) Air Fit (trade name) No. S manufactured by Unicharm Co., Ltd. and Dawang Paper Co., Ltd. were used directly as disposable diapers on the market in October 2013. The surface sheet of GOON (registered trademark) はじめての肌着 (trade name) S size manufactured by the company. The details of the fiber treatment agents shown in Table 1 and Table 2 below are as follows. Potassium lauryl phosphate: manufactured by Toho Chemical Industry Co., Ltd., neutralized potassium hydroxide of "Phosphanol ML-200" · Potassium stearyl phosphate: manufactured by Kao Co., Ltd., hydrogen of "GRIPPER 4131" Potassium oxide neutralizer · Dimethyl polysiloxane: Shin-Etsu Chemical Co., Ltd., "KM-903" · POE (addition molar number 3) lauryl phosphate potassium salt: Miyoshi Oil & Fat Co., Ltd. Manufacturing, "Amphorex MP-2K" ·POE, POP modified polysiloxane: manufactured by Shin-Etsu Chemical Co., Ltd., "X-22-4515"

. POE (addition molar number 1) stearylamine: manufactured by Kawaken Fine Chemicals, "Amisol SDE"

. Stearyl betaine: manufactured by Kao Co., Ltd., "Amphitol 86B"

. Dioctyl sulfosuccinate: manufactured by Kao Co., Ltd., "Pelex OT-P"

[Evaluation]

Regarding the non-woven fabrics obtained in the Examples and Comparative Examples (diapers in Comparative Examples 3 and 4), the first non-woven fabric layer 11 before the passage of artificial urine and after the passage of artificial urine was measured by the above method And the contact angle of the constituent fibers of the second non-woven fabric layer 12. The first non-woven fabric layer 11 is measured at the position of the top of the convex portion 14, and the second non-woven fabric layer 12 is measured at the position of the concave portion. The results are shown in Table 1 and Table 2.

In addition, in Comparative Example 3, the top of the concavo-convex structure continuously extending in the longitudinal direction of the surface sheet of the diaper was regarded as the first nonwoven fabric layer 11, and the bottom was evaluated as the bottom of the second nonwoven fabric layer 12. In the evaluation of the contact angle after passing the liquid, after passing a specific amount of liquid, spray a cold spray without spraying to the passing part to solidify the hot melt and weaken the adhesive force. Carefully peel off the surface sheet. Evaluation of the contact angle after passing the liquid. Furthermore, regarding Comparative Example 4, the top of the uneven structure of the surface sheet of the diaper was evaluated as the first nonwoven fabric layer 11, and the bottom of the nonwoven fabric existing below it was regarded as the second nonwoven fabric layer 12. The evaluation of the contact angle after passing the liquid was carried out by the same method as in Comparative Example 3.

In addition, absorbent articles were manufactured using the nonwoven fabrics obtained in Examples and Comparative Examples as surface sheets, and the amount of moisture repellent was measured by the following method. The moisture repellent amount is measured by dividing it into the surface sheet-derived material and the absorber-derived material. The results are also shown in Table 1 and Table 2.

[Determination of dehumidification capacity]

The Merries (registered trademark) belt type (S size) of the disposable diaper manufactured by Kao Co., Ltd. commercially available in October 2013 was sprayed with cold spray to cure the adhesive and remove the surface sheet. The non-woven fabrics obtained in the examples and comparative examples were re-attached to replace the removed surface sheet, and an absorbent article to be measured was produced. Among them, in Comparative Examples 3 and 4, this operation was not performed, and the diaper itself was used for the measurement of the amount of dehumidification. Spread the absorbent article to be measured into a flat shape, and place it horizontally with the skin facing side (surface sheet side) facing upward. In this state, 30 g of artificial urine was injected 3 times at a flow rate of 5 g/s (90 g in total). After the first injection, 10 minutes later, the second injection was performed. The injection site of the artificial urine is set to be the center in the horizontal direction at a position 130 mm inward in the vertical direction from the end on the abdominal side in the vertical direction (longitudinal direction) of the absorber. After injecting the second artificial urine twice into the absorbent article, let it stand for 10 minutes. After that, place the superimposed 4 pieces of collagen film (Coffi J manufactured by Viscofan Co., Ltd.) cut into 7 cm squares in the absorbent article At the injection site of the artificial urine, press the collagen membrane at 7kPa for 1 minute. This allows the collagen membrane to absorb the artificial urine absorbed and retained by the absorbent article. Thereafter, the quality of the collagen membrane absorbed by the artificial urine was measured. Subtract the mass of the collagen membrane before absorption from this mass to calculate the mass of the artificial urine absorbed by the collagen membrane. This value was taken as the moisture repelling amount (the sum of the moisture repelling amount derived from the surface sheet and the moisture repelling amount derived from the absorber). In addition, for the measurement of the amount of moisture from the surface sheet, the artificial urine was injected for the third time and left for 10 minutes. After that, only the surface sheet was peeled off, and an OHP film was interposed between the absorber and the surface sheet. (VF1300 manufactured by KOKUYO), measure the amount of liquid back by the same method as above, as the amount of dehumidification derived from the surface sheet. The dehumidification amount derived from the absorber is obtained by subtracting the dehumidification amount derived from the surface sheet from the above-mentioned liquid return amount.

[表2]

如表1及表2所示之結果所示，可知若使用各實施例中所獲得之不織布作為吸收性物品用之表面片材，則與比較例之不織布相比，反濕量變少。尤其對第2不織布層施加主成分與第1不織布層相同之纖維處理劑的比較例2於通液後接觸角差為0度，與任一實施例相比反濕均較嚴重。相對於比較例2，第2不織布層中包含50%之不同於第1不織布層之主成分的實施例8於通液後之接觸角差大於0度，與比較例2相比反濕較輕度。 [產業上之可利用性] 根據本發明，提供一種即便於複數次通液後亦能夠維持對液體透過性之控制的不織布。使用該不織布之吸收性物品有效防止發生反濕。[Table 1]

[Table 2]

As shown in the results shown in Table 1 and Table 2, it can be seen that when the nonwoven fabric obtained in each example is used as a surface sheet for absorbent articles, the amount of moisture repelling becomes smaller than that of the nonwoven fabric of the comparative example. In particular, Comparative Example 2 in which a fiber treatment agent with the same main component as that of the first non-woven fabric layer was applied to the second non-woven fabric layer had a contact angle difference of 0 degrees after passing the liquid, and the dehumidification was more serious than that of any of the examples. Compared with Comparative Example 2, Example 8 in which the second non-woven fabric layer contains 50% of the main component different from that of the first non-woven fabric layer has a contact angle difference of greater than 0 degrees after the liquid is passed, and the anti-wetting is lighter than that of Comparative Example 2. degree. [Industrial Applicability] According to the present invention, there is provided a non-woven fabric that can maintain control of liquid permeability even after passing the liquid several times. Absorbent articles using this non-woven fabric can effectively prevent moisture reversal.

10‧‧‧Non-woven 11‧‧‧The first non-woven layer 11A‧‧‧Region 1 12‧‧‧The second non-woven layer 12A‧‧‧Section 2 13‧‧‧Joint 14‧‧‧Protrusion 15‧‧‧Concave 16s‧‧‧Space

Fig. 1 is a cross-sectional view in the thickness direction showing an embodiment of the nonwoven fabric of the present invention. Fig. 2(a) is a perspective view of an example of the non-woven fabric shown in Fig. 1, and Fig. 2(b) is a perspective view of another example of the non-woven fabric shown in Fig. 1. Fig. 3 is a cross-sectional view in the thickness direction showing another embodiment of the nonwoven fabric of the present invention. Fig. 4 is a cross-sectional view in the thickness direction showing still another embodiment of the nonwoven fabric of the present invention. Fig. 5 is a cross-sectional view in the thickness direction showing still another embodiment of the nonwoven fabric of the present invention.

10: Non-woven fabric

11: The first non-woven layer

12: The second non-woven layer

13: Joint

14: Convex

15: recess

16: space

Claims (31)

A non-woven fabric that produces a first zone and a second zone in which the hydrophilicity of the constituent fibers is different from each other in the thickness direction when 90 g of artificial urine is passed at a speed of 5.0 g/s under no pressure, and The first area is the area including the surface of the non-woven fabric, and the second area is the area adjacent to the first area when viewed in the thickness direction of the non-woven fabric. When the hydrophilicity is expressed by the contact angle with water, the structure of the first area The contact angle of the fiber is greater than the contact angle of the constituent fibers in the second area. Such as the non-woven fabric of claim 1, in which a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and when the fiber treatment agent has two or more main components, no matter which main component is focused on In this case, the principal components in the first area and the second area are both different. Such as the non-woven fabric of claim 1 or 2, in which the fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the main component of the fiber treatment agent applied to the constituent fibers of the first region and the configuration of the second region The main components of the fiber treatment agent applied to the fiber are different. Such as the non-woven fabric of claim 1, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the main component of the above-mentioned fiber treatment agent applied to the constituent fibers of the second region is polyorganosilicon having a hydrophilic group Oxane. The non-woven fabric of claim 4, wherein the above-mentioned hydrophilic group is a hydroxyl group, a polyoxyalkylene group, an amino group, a diamine group, a polyglycerol group, an epoxy group, a methanol group, a carboxyl group, a glycol group or a methacrylic group, or A combination of two or more of these. The non-woven fabric of claim 4 or 5, wherein the above-mentioned hydrophilic group is a polyoxyalkylene group or a polyglycerin group. Such as the non-woven fabric of claim 1, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and one of the main components of the above-mentioned fiber treatment agent applied to the second region is polyoxyalkylene-modified poly Silica. The non-woven fabric of claim 7, wherein the ratio of the polyoxyalkylene-modified polysiloxane contained in the fiber treatment agent applied to the constituent fibers of the second region is preferably 15% by mass or more, more preferably 20 Mass% or more, more preferably 25% by mass or more, more preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less. Such as the non-woven fabric of claim 8, wherein the repeating number of the oxyalkylene group in the polyoxyalkylene group is preferably 3 or more, more preferably 5 or more, more preferably 7 or more, and more preferably 40 or less, more Preferably it is 30 or less, More preferably, it is 20 or less. Such as the non-woven fabric of claim 1, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and the main component of the fiber treatment agent applied to the first region is preferably selected from hydrocarbon oil, fluorine oil, At least one of the group consisting of fatty acid ester, polyoxyalkylene modified polysiloxane, polyorganosiloxane, and nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more, It is more preferable to use at least one selected from the group consisting of polyoxyalkylene-modified polysiloxane, polyorganosiloxane, and nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more , It is more preferable to use at least one selected from the group consisting of polyorganosiloxanes and nonionic and ionic surfactants having an alkyl group with 16 or more carbon atoms. For example, the non-woven fabric of claim 1 contains a laminated structure including a first non-woven fabric layer and a second non-woven fabric layer. The first non-woven fabric layer becomes an area corresponding to the first area, and the second non-woven fabric layer becomes an area corresponding to the second area. Such as the non-woven fabric of claim 1, wherein the contact angle of the constituent fibers of the first area after the artificial urine is passed through is preferably 80 degrees or more, more preferably 85 degrees or more, more preferably 90 degrees or more, and more It is preferably 100 degrees or less, more preferably 97 degrees or less, and still more preferably 94 degrees or less. Such as the non-woven fabric of claim 1, wherein the contact angle of the constituent fibers in the second region is set to be smaller than the contact angle of the constituent fibers in the first region. After the artificial urine is passed through, it is preferably 65 degrees or more, more preferably 70 degrees or more, more preferably 75 degrees or more, more preferably 90 degrees or less, more preferably 87 degrees or less, and still more preferably 84 degrees or less. For the non-woven fabric of claim 1, after the artificial urine is passed through, the difference between the contact angle of the constituent fibers in the first region and the contact angle of the constituent fibers in the second region (the former-the latter) is preferably greater than 0 degrees, It is more preferably 3 degrees or more, still more preferably 5 degrees or more, more preferably 30 degrees or less, more preferably 25 degrees or less, and still more preferably 20 degrees or less. Such as the non-woven fabric of claim 1, wherein the contact angle of the constituent fibers of the first region before the artificial urine is passed is preferably 75 degrees or more, more preferably 78 degrees or more, and still more preferably 81 degrees or more. It is preferably less than 90 degrees, more preferably 87 degrees or less, and still more preferably 84 degrees or less. Such as the non-woven fabric of claim 1, wherein the contact angle of the constituent fibers in the second region is set to be smaller than the contact angle of the constituent fibers in the first region. It is preferably 60 degrees or more before the artificial urine is passed through, and more preferably 65 degrees or more, more preferably 70 degrees or more, more preferably 85 degrees or less, more preferably 80 degrees or less, and still more preferably 75 degrees or less. For the non-woven fabric of claim 1, before the artificial urine is passed through, the difference between the contact angle of the constituent fibers in the first region and the contact angle of the constituent fibers in the second region (the former-the latter) is preferably greater than 0 degrees, It is more preferably 3 degrees or more, still more preferably 5 degrees or more, more preferably 30 degrees or less, more preferably 25 degrees or less, and still more preferably 20 degrees or less. For example, the non-woven fabric of claim 1, in the state before the artificial urine is passed, the contact angle of the constituent fibers in the first area is less than 90 degrees, and in the state after the artificial urine is passed, the first area is The contact angle of the constituent fibers is 90 degrees or more. For the non-woven fabric of claim 1, in the state before the artificial urine is passed through, the contact angle of the constituent fibers in the first region is greater than the contact angle of the constituent fibers in the second region. Such as the non-woven fabric of claim 1, which has an uneven structure on the surface of the first area. For example, the non-woven fabric of claim 20, which contains a laminated structure including a first non-woven fabric layer corresponding to the first area and a second non-woven fabric layer corresponding to the second area. The first non-woven fabric layer and the second non-woven fabric layer are partially joined to form a plurality of The first non-woven fabric layer protrudes away from the second non-woven fabric layer at a portion other than the joint portion, forming a plurality of convex portions, and the first non-woven fabric layer and the second non-woven fabric layer are formed inside the convex portions The space delineated. Such as the non-woven fabric of claim 1, wherein a fiber treatment agent is applied to the constituent fibers of the first region and the second region, and one of the main components of the above-mentioned fiber treatment agent applied to the second region is polyoxyalkylene-modified poly Silicone, except for polyoxyalkylene-modified polysiloxane, the main component is the alkali metal salt of alkyl phosphate, polyoxyethylene polyol fatty acid ester, alkyl betaine, alkyl sulfonic acid , Alkyl sulfuric acid, dialkyl sulfonic acid or polyoxyethylene alkyl amide. An absorbent article comprising the non-woven fabric as claimed in claim 1, and the first area in the non-woven fabric is arranged in a manner facing the wearer's skin. Such as the absorbent article of claim 23, which uses the above-mentioned non-woven fabric as a surface sheet, and arranges the first area in the non-woven fabric in such a way as to face the wearer's skin. A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as in claim 1, and has the following steps: applying a first fiber treatment agent from one side of the non-woven fabric, and applying a second fiber treatment agent with a composition different from the first fiber treatment agent from the other side A fiber treatment agent, and the main components of the first fiber treatment agent and the second fiber treatment agent are different. A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as claimed in claim 1, and has the following steps: a first fiber web containing fibers applied with a first fiber treatment agent and a first fiber web containing fibers having a composition different from the first fiber treatment agent The second fiber web of the fibers of the second fiber treatment agent is laminated, and then the laminated fiber web is non-woven, and the main components of the first fiber treatment agent and the second fiber treatment agent are different. A method for manufacturing a non-woven fabric, which is the method for manufacturing a non-woven fabric as in claim 1, and has the following steps: applying a first fiber treatment agent to the first fiber web, and applying a composition different from the first fiber treatment agent to the second fiber web In the second fiber treatment agent, two fiber webs are laminated, and then the laminated fiber web is non-woven, and the main components of the first fiber treatment agent and the second fiber treatment agent are different. The manufacturing method of any one of claims 25 to 27, wherein the first fiber treatment agent and the second fiber treatment agent have different main components, and the first and second areas adjacent in the thickness direction of the nonwoven fabric are The first fiber treatment agent is applied to one area, and the second fiber treatment agent is applied to the second area. The manufacturing method according to any one of claims 25 to 27, wherein one of the main components of the second fiber treatment agent is polyoxyalkylene-modified polysiloxane. The manufacturing method of claim 29, wherein the ratio of the polyoxyalkylene-modified polysiloxane contained in the second fiber treatment agent is preferably 15% by mass or more, more preferably 20% by mass or more, and still more preferably 25 Mass% or more, more preferably 60 mass% or less, more preferably 50 mass% or less, and still more preferably 40 mass% or less. The manufacturing method according to any one of claims 25 to 27, wherein the main component of the first fiber treatment agent is preferably selected from hydrocarbon oil, fluorine oil, fatty acid ester, polyoxyalkylene modified polysiloxane, polyoxyethylene At least one of the group consisting of organosiloxanes and nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more, more preferably selected from the group consisting of polyoxyalkylene-modified polysiloxanes , Polyorganosiloxane, and at least one of the group consisting of nonionic and ionic surfactants having an alkyl group with a carbon number of 16 or more, and it is more preferred to use polyorganosiloxanes and those with At least one of the non-ionic and ionic surfactants of an alkyl group with 16 or more carbon atoms.

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