JP2016067897A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article which achieves both thinness and absorption capacity of an absorber at a high level, and gives a sense of security and comfortable wearing feeling when the absorbent article is worn.MEANS: An absorbent article comprises a front surface sheet, a rear surface sheet, and a fluid holding absorber disposed between the front surface sheet and the rear surface sheet. A second sheet is disposed between the front surface sheet and the absorber. The absorber has a density higher than 0.12 g/cm. The second sheet has a capillary force of 1.5×10N or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to absorbent articles such as sanitary napkins and disposable diapers.

  Absorbent articles such as sanitary napkins usually have a top sheet, a back sheet, and an absorbent body between the two sheets, and are used with the surface of the top sheet facing the skin of the wearer. In such an absorbent article, it is required as a basic absorption performance that the excretory liquid is quickly transmitted from the top sheet to the absorbent body so that the liquid does not touch the skin. In order to enhance the absorption performance, there is a technique of arranging a liquid-permeable sheet member between the top sheet and the absorber (see, for example, Patent Documents 1 to 3). Moreover, there exists a technique which improves a nonwoven fabric in order to improve the liquid permeability of a surface sheet (for example, refer patent document 4).

JP 2004-33236 A JP 2004-49529 A JP 2013-74934 A JP 2004-256935 A

The liquid permeability of the above-mentioned sheet member or the like can contribute to the improvement of the absorption performance in combination with other members, particularly the absorber. With respect to the absorbent body, the thickness tends to be thinner in order to reduce the uncomfortable feeling when the absorbent body is worn. In particular, in order to reduce the thickness without reducing the liquid holding capacity of the absorber, the density may be increased without reducing the basis weight. In this case, the gap into which the liquid enters is narrowed, and excretory liquids such as menstrual blood and vaginal discharge that have a high viscosity and a low diffusion rate are difficult to travel throughout the absorbent body. Therefore, when the excretion amount is large, it may occur that it cannot be handled quickly. Therefore, even if such a thin absorber is used, there is a demand for a material that does not leave a liquid on the top sheet, has a high absorbency, and can feel a comfortable and comfortable feeling.
In view of the above points, the present invention relates to an absorbent article that provides both a thin absorbent body and excellent absorbency at a high level, and provides a safe and comfortable wearing feeling when worn.

The present invention includes a top sheet, a back sheet, and a liquid-retaining absorbent disposed between the top sheet and the back sheet, and a second sheet is disposed between the top sheet and the absorbent. There is provided an absorbent article, wherein the absorbent body has a density higher than 0.12 g / cm ³ , and the second sheet has a capillary force of 1.5 × 10 ³ N or more.

  The absorptive article of the present invention can make the thinness of an absorber and excellent absorption power compatible at a high level.

It is the partial notch perspective view which showed typically the sanitary napkin as one Embodiment in this invention from the skin surface direction. (I) is a perspective view which shows preferable one Embodiment of a surface sheet, (ii) is a partially expanded view of sectional drawing in alignment with the thickness direction of the surface sheet of (i).

About the absorbent article of this invention, the sanitary napkin 10 as the preferable embodiment is shown, and it demonstrates below, referring drawings.
As shown in FIG. 1, a sanitary napkin 10 (hereinafter, also simply referred to as a napkin 10) of the present embodiment is a liquid-permeable surface sheet 1 disposed on the skin contact surface side, the non-skin contact surface side. The back sheet 2 is disposed on the front side, and the absorbent body 3 is disposed between the two sheets. A liquid-permeable second sheet 4 is disposed between the top sheet 1 and the absorber 3. The top sheet 1 and the back sheet 2 are joined outside the outer peripheral edge of the absorbent body 3 without the absorbent body 3 interposed. Furthermore, on the skin contact surface side of the sanitary napkin 10, a leak-proof groove 5 squeezed from the top sheet 1 to the absorber 3 is disposed, and the leak-proof groove 5 has an annular shape in plan view. .
The sanitary napkin 10 thus formed has a vertically long shape having a vertical direction (Y direction) and a horizontal direction (X direction) orthogonal to the vertical direction. The sanitary napkin 10 is arranged with the top sheet 1 side facing the wearer's skin contact surface and the vertical direction extending from the lower abdomen side to the buttocks side, and the width direction along the line connecting the left and right feet. Worn out in the direction.

  The sanitary napkin 10 has a crotch part C covering the excretion part of the wearer, a front part F corresponding to the lower abdominal part side in front of the crotch part C, and a rear part R corresponding to the rear buttocks side. In the crotch part C, there is a liquid absorption part C1 that directly receives excretion liquid at the center in the width direction. The crotch part C in this embodiment is a central region when the sanitary napkin 10 is divided into three regions in the vertical direction. In this section, the front part F and the rear part R are determined based on the crotch part C. Therefore, a division position changes with lengths of an absorptive article set up according to a purpose of use. For example, in the case of an absorbent article having a wide rear flap that covers the buttocks, the crotch C is closer to the front of the napkin.

  In the present invention, unless otherwise specified, the side in contact with the human body is referred to as the skin surface side, the skin contact surface side or the surface side, and the opposite side is referred to as the non-skin surface side, the non-skin contact surface side or the back surface side. That's it. The direction positioned on the front side of the human body when worn is referred to as the front, and its end is referred to as the front end, and the direction positioned on the rear is referred to as the rear, and the end is referred to as the rear end. The direction connecting the front end portion and the rear end portion, that is, the direction extending from the wearer's belly side portion to the back side portion via the crotch portion is referred to as the longitudinal direction (Y direction) of the absorbent article. A direction orthogonal to the vertical direction is referred to as a horizontal direction (X direction). Moreover, the normal line direction of the surface or back surface of an absorbent article is called thickness direction, and the quantity is called thickness.

The absorber 3 has a density higher than 0.12 g / cm ³ . Further, the density, 0.13 g / cm ³ or more preferably, 0.14 g / cm ³ or more is more preferable. Thereby, it is possible to reduce the thickness while ensuring a sufficient liquid holding capacity of the absorbent body 3, and to reduce the uncomfortable feeling when the napkin 10 is attached. On the other hand, the upper limit of the density is appropriately determined from the viewpoint of preventing curing of the absorber and securing the absorption performance. For example, preferably 3.0 g / cm ³ or less, more preferably 2.75 g / cm ³ or less, 2.5 g / cm ³ or less is more preferable.
In addition, the said density is a density of the absorber 3 whole obtained by the following measuring method, and when it consists of an absorptive core and a core wrap sheet | seat, it is a density of an absorptive core part.

(Density measurement method)
The density of the absorber 3 is measured according to JIS-P8118: 1998, and is specifically calculated by the following equation.
Density D (g / cm ³ ) = basis weight W (g / m ² ) × 10 ³ / thickness T (mm)
The basis weight W in the above formula is measured according to the method described in JIS-P8124. Specifically, the mass of the absorber 3 is measured with a scale, and the basis weight W is calculated by dividing the measured value by the area. The thickness T in the above formula is measured according to JIS-P8118: 1998. However, the thickness T is measured using a peacock precision measuring instrument (model R1-C), which is a micrometer having two parallel pressure surfaces (a fixed pressure surface and a movable pressure surface). The diameter is 5 mm, the pressure is 100 kPa or less, and the size of the measurement test piece is not less than the size of the following plate. A 20 mm × 20 mm plate (mass 5.4 g) is placed on the test piece, the measuring element movable pressurizing surface is operated at a speed of 2 mm / s, applied to the plate, and the value immediately after stabilization is read. The pressure between the pressing surfaces (pressure applied to the test piece) is 1.3 kPa or less.

In addition, when the thickness of the absorber 3 is not constant, for example, there is a portion where the thickness is locally thicker, such as a middle-high portion, or there is a step by folding the sheet-like absorber in two, or a leak-proof groove In some cases, there may be a concave groove. The thickness of the absorber 3 in this case is measured by selecting the thickness of the portion near the center where the liquid excreted during use by the user is absorbed. Based on this, the portion where the thickness is measured is cut out in a predetermined area, and the weight is measured to calculate the basis weight, and the value is substituted into the above formula to measure the density of the absorbent body 3.
In addition, when the absorber 3 has a partially rough portion and a dense portion, if the dense portion and the rough portion can be clearly discerned by visual inspection, only the dense portion of the absorber is removed with a razor or the like. It is the average density of the whole which extracts by cutting and calculates the value of a predetermined density by calculating thickness and area. When it cannot be discriminated visually, such as when it is continuously changing, the absorber is cut into 3 cm x 3 cm, and only the middle part of the absorber is divided into three parts, and the density from the thickness and area. And the average density is adopted.

When taking out the absorber to be measured from a commercially available napkin or the like, the hot melt that bonds the materials is solidified by cold spray or the like, and then carefully peeled off. In the state where the absorbent core and the core wrap sheet are integrated, the absorber is subjected to a load of 1.3 kPa and the thickness is measured. Then, the absorber is immersed in an organic solvent or the like, and the core wrap sheet is separated from the absorbent core. And thickness of this core wrap sheet | seat is measured under 1.3 kPa load, and the thickness of an absorptive core is calculated by drawing from the thickness of the whole absorber.
Note that the above-described method for taking out the member is applied in various measurements described later.

The thickness of the liquid absorption part C1 of the absorber 3 is preferably 3.2 mm or less, more preferably 3.0 mm or less, and even more preferably 2.8 mm or less, according to the measurement method described above. As described above, the liquid absorption part C1 corresponds to a part that directly receives excretion liquid in the crotch part C of the napkin 10. When the thickness is within the above range, the user can easily recognize that the napkin is thin. Further, the lower limit is preferably 1.0 mm or more, more preferably 1.2 mm or more, and further preferably 1.4 mm or more from the viewpoint of securing the absorption capacity and imparting appropriate fit to the user. In addition, the thickness here is the thickness before liquid absorption of the absorber 3, and is the thickness before mounting.
Moreover, it is preferable that the thickness of the liquid absorbing portion C1 is in the above range, and the thickness around the liquid absorbing portion C1 is thinner than this. Thereby, liquid absorption part C1 can be fitted to a wearer's excretion point, and the uncomfortable feeling in the peripheral part contact | abutted to an inner crotch can be reduced.

  Further, the absorption rate under pressure (absorption time under pressure) of the absorbent body 3 is preferably 14.5 seconds or more, more preferably 16.5 seconds or more, and further preferably 18.5 seconds or more. Thereby, the liquid stays easily in the second sheet 4 and the influence of the physical properties of the second sheet 4 appears more remarkably. That is, the liquid diffusibility of the second sheet 4 is sufficiently exhibited, and the liquid can be evenly absorbed over a wide area of the absorbent body. In addition, the upper limit is preferably 40 seconds or less, more preferably 35 seconds or less, and even more preferably 30 seconds or less, from the viewpoint of not impeding liquid absorbency when the consumer excretes in the sitting state.

(Measurement method of absorption rate under pressure (absorption time under pressure))
The absorption rate under pressure here is the absorption rate under pressure of the sanitary napkin, and is measured by the following method.
With the sanitary napkin to be measured spread in a flat shape and fixed on a horizontal surface with the top sheet facing up, an acrylic plate with a cylindrical injection section is placed on the top sheet in the liquid absorbing section C1. Make it. Further, a weight is placed on the acrylic plate, and a load of 5 g / cm ² is applied to the center of the sanitary napkin. The injection part provided in the acrylic plate has a cylindrical shape with an inner diameter of 10 mm. In the acrylic plate, the central axis of the cylindrical injection portion coincides with the central axis in the longitudinal direction and the width direction, and an inner diameter of 10 mm communicates between the inside of the cylindrical injection portion and the surface sheet facing surface of the acrylic plate. Through-holes are formed.
Next, the acrylic plate is arranged so that the central axis of the cylindrical injection portion coincides with the central portion of the sanitary napkin in plan view, and 4 g of blood is injected from the cylindrical injection portion and absorbed by the sanitary napkin. The time (seconds) from when the blood reaches the surface of the napkin until the total amount of 4 g is absorbed by the napkin is measured, and this is taken as the absorption rate. That is, this absorption rate indicates the time required for a predetermined amount (4 g) of blood to be absorbed.
The blood used herein is equine defibrillated blood manufactured by Japan Biotest Laboratories Co., Ltd. adjusted to 8.0 cP.

  In the absorbent body 3, the above-mentioned density for thinning acts to increase the capillary force between the fibers. That is, the liquid drawing force at the liquid uptake point of the absorber 3 is increased. However, at the same time, the distance between the fibers of the absorbent body 3 is also shortened, so that the liquid diffusibility inside the absorbent body 3 of the excretory fluid having high viscosity such as menstrual blood and cage is lowered. For this reason, the liquid drawn into the absorber 3 tends to stay around the liquid absorbing portion C1, and there is a limit to the amount of liquid drawn quickly and continuously from the top sheet.

  On the other hand, the second sheet 4 described below supplements the drawing of the liquid from the top sheet 1. That is, the superposition of the absorber 3 having the above density and the second sheet 4 having the following capillary force contributes to a high level of both thinning of the napkin 10 and prevention of liquid residue on the top sheet 1. This point will be described below.

The second sheet 4 is a separate sheet from the absorbent body 3 and is superimposed on the skin contact surface of the absorbent body 3 between the topsheet 1 and the absorbent body 3. The second sheet 4 is made of hydrophilic fibers and has a capillary force of 1.5 × 10 ³ N or more. Further, the capillary force is preferably 1.6 × 10 ³ N or more, and more preferably 1.7 × 10 ³ N or more.
This capillary force is effective in supplementing the absorbing power of the absorbent body 3 in combination with the above-described density of the absorbent body 3 and enhancing the drawability of the liquid from the topsheet 1. In particular, it is effective to draw a highly viscous liquid such as menstrual blood or a cage from the surface sheet 1 without clogging the absorber.
Furthermore, the second sheet 4 having the above-described capillary force has high diffusibility in the planar direction of the liquid drawn from the top sheet 1. Due to this liquid diffusibility, the liquid collecting ability of the second sheet 4 is high, and even if there is repeated excretion or a large amount of excretion at a time, the retention of the liquid in the top sheet 1 can be suppressed. Further, due to the liquid diffusibility in the second sheet 4, the liquid can be delivered over a wide area to the absorber 3 in contact therewith. Thereby, the liquid absorption power of the high-density absorber 3 is utilized without surplus, and the liquid is smoothly delivered. As a result, the retention of the liquid in the second sheet 4 is also suppressed, and the action of promoting the liquid transfer from the top sheet 1 to the absorber 3 can be sustained.
Such an action of the capillary force of the second sheet 4 cannot sufficiently contribute to the absorption power of the napkin for an absorber having a density that is too low, and the above combination is effective.
In this way, by superposing the second sheet 4 having a high capillary force on the skin contact surface side of the absorbent body 3 having the above-described density, the liquid remaining on the top sheet is small and the redness of menstrual blood is not noticeable. Thereby, the user can realize that the sanitary napkin is thin and has good absorbency.

Furthermore, the upper limit of the capillary force of the second sheet 4 is appropriately determined from the viewpoint of preventing the second sheet 4 from being cured and maintaining liquid diffusibility. For example, 3.0 × 10 ³ N or less is preferable, 2.9 × 10 ³ N or less is more preferable, and 2.0 × 10 ³ N or less is more preferable.
The capillary force of the second sheet 4 in the above range is preferably higher than the capillary force of the top sheet 1 from the viewpoint of liquid drawability.

(Measurement method of capillary force)
The method for measuring the capillary force can be calculated by the following Laplace equation.
w (capillary force) = 2 × γ (surface tension of the target liquid) × cos θ (calculated from the contact angle of the fiber) / R (capillary radius; in this calculation, ½ of the interfiber distance is calculated as the capillary radius)
In addition, about the contact angle of a fiber and the distance between fibers in the said formula, what was computed by the method of the following description is used.

(Measurement method of contact angle)
A fiber is taken out from a predetermined portion in the thickness direction of the second sheet, 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 Co., Ltd., 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 ms.
In the recorded video, the first image of water drops on the fiber taken out from the non-woven fabric is attached to the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2 method) The image processing algorithm is non-reflective, the image processing image mode is frame, the threshold level is 200, and no curvature correction is performed). Based on this, the angle formed by the surface of the water droplet that touches the air and the fiber is calculated as 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 second decimal place) is defined as the contact angle.

(Measurement method of distance between fibers)
The inter-fiber distance is obtained by measuring the thickness of the nonwoven fabric to be measured as follows and applying it to Equation (1).
First, the nonwoven fabric to be measured is cut into a longitudinal direction of 50 mm and a width direction of 50 mm to produce a cut piece of the nonwoven fabric. This cut piece is placed on the napkin absorbent body, and a sanitary napkin using a nonwoven fabric to be measured as a surface sheet is prepared.
The thickness of the nonwoven fabric is measured under a pressure of 49 Pa under the state of being placed on the napkin absorber. The measurement environment is a temperature of 20 ± 2 ° C., the relative humidity is 65 ± 5%, and the measurement instrument is a microscope (manufactured by Keyence Corporation, VHX-1000). First, an enlarged photograph of the nonwoven fabric cross section is obtained. In the magnified picture, a photograph of a known size is taken at the same time. A scale is matched with the enlarged photograph of the cross section of the nonwoven fabric, and the thickness of the nonwoven fabric is measured. The above operation is performed three times, and the average value of the three times is defined as the thickness [mm] of the dried nonwoven fabric. In the case of a laminated product, the boundary is determined from the fiber diameter, and the thickness is calculated.
Next, the inter-fiber distance of the fibers constituting the nonwoven fabric to be measured is determined by the following formula based on Wrotnowski's assumption. An expression based on the assumption of Wrotnowski is generally used when determining the inter-fiber distance of the fibers constituting the nonwoven fabric. According to a formula based on the assumption of Wrotnowski, the interfiber distance A (μm) is the thickness h (mm) of the nonwoven fabric, the basis weight e (g / m ² ), the fiber diameter d (μm) of the fibers constituting the nonwoven fabric, It is calculated | required by the following formula | equation (1) by fiber density (rho) (g / cm < ³ >).
In addition, fiber diameter d (micrometer) measures 10 fiber cross sections of the cut fiber using a scanning electron microscope (Seiko Instruments Co., Ltd. DSC6200), and makes the average value the fiber diameter.
The fiber density ρ (g / cm ³ ) is measured using a density gradient tube in accordance with the measurement method of the density gradient tube method described in the JIS L1015 chemical fiber staple test method (URL is http: // kikakuui. com / l / L1015-2010-01.html, JIS Handbook Fiber-2000 for books, described in P.764-765 of (Japan Standards Association).
The basis weight e (g / m ² ) is cut into a predetermined size (0.12 m × 0.06 m or the like), and after mass measurement, the basis weight is calculated by the following formula.
Mass / Area obtained from a predetermined size = basis weight (g / m ² )

It is preferable that both the members are in contact, that is, in direct contact, between the second sheet 4 and the absorbent body 3 in order to allow mutual capillary forces to interact with each other and to ensure cooperation of liquid delivery. Moreover, it is more preferable that both members are fixed so that the contact state is not separated. Examples of the immobilization method include a method of adhering with a rough coating pattern such as a spiral shape with an adhesive such as a hot melt adhesive.
Moreover, it is preferable that the 2nd sheet | seat 4 is a magnitude | size which covers the skin contact surface of the absorber 3 from said liquid diffusibility viewpoint. Furthermore, from the viewpoint of preventing liquid leakage from the peripheral edge of the napkin 10 due to liquid diffusion, it is more preferable that the length is smaller in the vertical direction and the width direction than the outer shape of the absorber 3.
In addition, in order for the second sheet 4 to smoothly draw in the liquid from the top sheet 1, it is preferable that both members are in contact, that is, in direct contact, and the contact state is preferably fixed. Examples of the immobilization method include a method of adhering with a rough coating pattern such as a spiral shape with an adhesive such as a hot melt adhesive.

  Various methods can be used to obtain the above-described capillary force. For example, the second sheet 4 is made of a fiber material, and a method of increasing the hydrophilicity of the fiber is exemplified. Moreover, the method of shortening the distance between fibers of this fiber (namely, raising a fiber density) is mentioned. Any one of various methods including these methods may be adopted, or a plurality of methods may be combined.

  As a method for increasing the hydrophilicity of the fiber, for example, it is preferable that a heat-fusible fiber having a fiber treatment agent attached to the second sheet 4 is included, and the fiber treatment agent contains polyoxyalkylene-modified silicone. The polyoxyalkylene-modified silicone is preferably contained in an amount exceeding 10% by mass, more preferably 12% by mass or more, based on the mass of the fiber treatment agent attached to the fiber. More preferably, the content is 14% by mass or more. The fiber treatment agent referred to here is to increase the hydrophilicity of the surface of the fiber as compared with that before the fiber treatment agent is adhered.

In the sheet member of the present invention, such as a non-woven fabric to which the fiber treatment agent is adhered, when analyzing the adhered fiber treatment agent, it is preferable to analyze according to the following procedure. First, the nonwoven fabric to be analyzed is washed with a suitable solvent. Examples of the cleaning solvent include a mixed solvent of ethanol and methanol and a mixed solvent of ethanol and water. When the sheet member to be analyzed is a sanitary product or a surface sheet or a second sheet of an absorbent article such as a disposable diaper for children or adults, the sheet member is joined to another member in the absorbent article. After the adhesive used is melted and softened by heating with a heating means such as a dryer, the surface sheet is peeled off, and the peeled sheet member is washed with a washing solvent.
Next, the total amount of the fiber treatment agent adhering to the sheet member is determined by drying the solvent (washing solvent containing the fiber treatment agent) used for washing the nonwoven fabric to be analyzed and quantifying the residue. Can be measured. In addition, after selecting an appropriate column and solvent according to the composition of the residue, each component is fractionated by high performance liquid chromatography, and each fraction is further subjected to MS measurement, NMR measurement, elemental analysis, etc. By performing the above, the structure of each fraction can be identified. When the fiber treatment agent contains a polymer compound, it becomes easier to identify the constituent components by using a technique such as gel permeation chromatography (GPC) together.
The above analysis method is similarly used for other components described later attached to various sheet members.

  The polyoxyalkylene-modified silicone is suitable for the second sheet 4 to have a capillary force that exhibits the above action. This is because the polyoxyalkylene-modified silicone has a polysiloxane chain, so that it does not easily penetrate into the inside of the synthetic resin fiber and tends to remain on the surface. Among silicones, polyoxyalkylene-modified silicone can easily increase the hydrophilicity by changing the type and degree of modification of the polyoxyalkylene-modified group. In addition, due to the property of easily remaining on the surface of the fiber, even if the second sheet 4 is subjected to a partial heat melting process (for example, formation of a leak-proof groove or an embossed part), the hydrophilicity in that part is maintained. is there. The second sheet is generally provided with a leak-proof groove, embossing, and the like due to the arrangement of the absorbent article. That is, it is preferable to use a polyoxyalkylene-modified silicone that has a property that tends to remain on the fiber surface and can maintain a high degree of hydrophilicity for hot melt processing.

The polyoxyalkylene-modified silicone is not particularly limited, and examples thereof include those described in paragraphs [0010] to [0012] of JP-A No. 2002-161474.
More specifically, as polyoxyalkylene modified silicone, what is represented by the following general formula (M) is preferable.

  In the formula, Me represents a methyl group, R represents a methylene group, a propylene group, a butylene group, an N- (aminoethyl) methylimino group, an N- (aminopropyl) propylimino group, or the like, and X represents a polyoxyalkylene group. . Examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and those obtained by copolymerizing these constituent monomers.

  The polyoxyalkylene-modified silicone preferably has an HLB (hydrophilic-lipophilic balance) of 5 or more, more preferably 6 or more, and even more preferably 7 or more in order to achieve the above-described capillary force. As a result, the polyoxyalkylene-modified silicone has an effect of a polyoxyalkylene group and easily increases the hydrophilicity of the fiber. Further, the upper limit of the HLB is preferably 16 or less, more preferably 15.5 or less, and even more preferably 15 or less, from the viewpoint of leaving the polyoxyalkylene-modified silicone on the fiber surface during various processing.

The polyoxyalkylene-modified silicone preferably has a modified group of either or both of polyoxyethylene (POE) modification and polyoxypropylene (POP) modification. Although it does not restrict | limit especially as what has this modification group, For example, there exists a thing of the paragraphs [0006] and [0012] of Unexamined-Japanese-Patent No. 2002-161474.
That is, examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, and a polyoxybutylene group, and polyoxyethylene alone or a random or block copolymer of polyoxyethylene and polyoxypropylene is particularly preferable. The added mole number is 2 to 20 moles, more preferably 5 to 15 moles. The polyoxyethylene to be copolymerized is preferably equimolar to or more than polyoxypropylene. The added mole number of polyoxyethylene is more preferably 10 moles or more from the viewpoint of ensuring water solubility. Further, the Si content in the modified silicone needs to be 20% or more and 70% or less. If it exceeds 70%, the stability of the product is poor and the cost is increased. Moreover, when less than 20%, sufficient hydrophilic performance cannot be obtained, which is not preferable. Examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and those obtained by copolymerizing these constituent monomers. It is necessary to contain 20% by weight or more based on polyoxyalkylene. If it is less than this, sufficient hydrophilic performance and water solubility cannot be obtained, which is not preferable. Further, the molecular weight of the modified silicone must be 1,000 or more and 100,000 or less, and if it is out of this range, the hydrophilicity is lowered, and this tendency is particularly remarkable when it is less than 1,000.
More specifically, polyoxyethylene (POE) polyoxypropylene (POP) modified silicone, polyoxyethylene (POE) modified silicone and the like can be mentioned.

  Further, the fibers constituting the second sheet 4 preferably contain more than 0.15% by mass of titanium oxide in a mass ratio of the fibers, and the content is more preferably 0.5% by mass or more. 1.0 mass% or more is still more preferable. By using fibers containing titanium oxide, the nonwoven fabric has increased whiteness and concealment. In particular, when a fiber containing titanium oxide is used as a constituent material of the second sheet 4, it has a high concealment property against body fluids such as menstrual blood and urine absorbed in the absorbent body, and a visual dry feeling from the appearance after use. Can be obtained. Moreover, 5 mass% or less is preferable and 4.5 mass% or less is more preferable from a viewpoint of productivity, the fiber elongation property, the card process property in the case of setting it as a nonwoven fabric, and the cut property in a post-processing process.

Titanium oxide preferably has a particle size in the range of, for example, 0.1 μm or more and 2 μm or less, and can be spun by containing it in a resin in the fiber spinning step.
In particular, when the fiber is a composite fiber having a core-sheath structure, the titanium oxide is preferably in the core from the viewpoint of preventing wear of the blade used when cutting the nonwoven fabric.

On the other hand, the interfiber distance for obtaining the above-mentioned capillary force is preferably 80 μm or less, more preferably 75 μm or less, and even more preferably 70 μm or less. Further, the lower limit is preferably 35 μm or more, more preferably 40 μm or more, and further preferably 45 μm or more from the viewpoint of preventing an increase in the amount of remaining liquid and a decrease in absorption rate due to the distance between fibers becoming too small. This inter-fiber distance can be obtained by the measurement method described above.
Further, in order to obtain the above-mentioned interfiber distance, the fineness of the fiber used is preferably 3.3 dtex or less, more preferably 2.7 dtex or less, and further preferably 2.2 dtex or less. Also, the lower limit is that if the fiber is made too fine, the film thickness of the oil agent decreases as the surface area of the fiber increases, the contact angle becomes hydrophobic, and the desired hydrophilicity is achieved. From the viewpoint of becoming difficult to achieve the target capillary force as a result, 1.0 dtex or more is preferable, 1.2 dtex or more is more preferable, and 1.5 dtex or more is more preferable. In addition, the hydrophilicity in a nonwoven fabric can be shown by the relative comparison of the contact angle of a constituent fiber. A small contact angle value indicates that the hydrophilicity is high, and a large contact angle value indicates that the hydrophilicity is low.

(Fineness measurement method)
The cross-sectional shape of the fiber is measured with an electron microscope, etc., and the cross-sectional area of the fiber (the cross-sectional area of each resin component in a fiber formed of a plurality of resins) is measured, and the resin is measured with a DSC (differential thermal analyzer). Is specified (in the case of multiple resins, the approximate component ratio is also), the specific gravity is determined, and the fineness is calculated.
For example, in the case of short fibers composed only of PET, the cross section is first observed and the cross sectional area is calculated. Then, by measuring with DSC, it is comprised from single component resin from melting | fusing point and peak shape, and it identifies that it is a PET core. Then, the fineness is calculated by calculating the mass of the fiber using the density and cross-sectional area of the PET resin.

Further, in the second sheet 4, it is preferable that a plurality of embossed portions (not shown) are dispersedly arranged in the plane direction on the skin contact surface side from the viewpoint of the liquid drawing property and liquid diffusibility described above. This embossed portion serves as a starting point for liquid drawing from the top sheet 1 and liquid delivery to the absorber 3, and in the fiber network structure, the embossed portion serves as a relay point for liquid diffusion.
In addition, the polyoxyalkylene-modified silicone is preferable because the embossed portion maintains hydrophilicity because it hardly enters the fiber and remains on the surface even when the fiber is consolidated during emboss formation.

  As the absorber 3 described above, an embodiment used for this type of article can be arbitrarily adopted as long as it has the above-described density. For example, the thing formed by coat | covering the absorptive core which consists of a hydrophilic fiber assembly with a core wrap sheet, a sheet-like thing, etc. are mentioned. The absorbent core may further contain a superabsorbent polymer. Examples of the sheet-like material include paper and pulp sheets manufactured using hydrophilic fibers as raw materials. Further, a water-absorbent sheet (for example, a water-absorbent sheet described in JP-A-8-246395 or JP-A-2004-275225) in which particles of a superabsorbent polymer are sandwiched and fixed between two sheets of absorbent paper or nonwoven fabric. Polymer sheet). The fibers constituting the fiber assembly include, for example, natural fibers such as wood pulp and plant pulp such as softwood and hardwood pulp, regenerated fibers such as cupra and rayon, semi-synthetic fibers such as acetate, polyolefins, polyamides, and polyesters. Synthetic fibers and the like can be mentioned, and one of these can be used alone, or two or more can be used in combination. Examples of the material for the core wrap sheet include paper and pulp sheets manufactured using hydrophilic fibers as raw materials, and hydrophilic nonwoven fabrics.

As the second sheet 4, as long as it has the above-described capillary force, an aspect used for this type of article can be arbitrarily adopted. For example, paper or nonwoven fabric obtained by wet papermaking can be used. Examples of the nonwoven fabric include air-through nonwoven fabric, airlaid nonwoven fabric, suction heat bond nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, and chemical bond nonwoven fabric. In particular, from the viewpoint of liquid permeation, an air-through nonwoven fabric, an airlaid nonwoven fabric, and a chemical bond nonwoven fabric are preferably used. When these nonwoven fabrics are comprised of hydrophobic fibers (for example, heat-fusible fibers), it is preferable to make them hydrophilic using the fiber treatment agent described above. When the second sheet 4 is made of a nonwoven fabric, the basis weight of the nonwoven fabric is 20 g / m ² or more and 50 g / m ² or less, and the water retention and liquid diffusibility of the second sheet 4 are impaired without impairing the wearing feeling. It is preferable from the point of not. The thickness of the second sheet 4 is preferably 0.5 mm or more and 2.0 mm or less, more preferably 0.5 mm or more and 1.5 mm or less.

  On the other hand, the surface sheet 1 is liquid permeable, and those used for this type of article can be used without particular limitation. From the viewpoint of increasing the liquid permeability, it is preferably made of a non-woven fabric using heat-fusible fibers to which a fiber treating agent is attached. The fiber treatment agent includes (A) polyorganosiloxane, (B) phosphate ester type anionic surfactant, and (C) an anionic surfactant represented by the following general formula (I), polyoxyalkylene-modified It is preferable to contain a polyhydric alcohol fatty acid ester or an alkylhydroxysulfobetaine. Such a surface sheet 1 has a gradient of hydrophilicity, promotes the drawing of the liquid by the second sheet 4, and further increases the absorbability of the napkin 10.

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. Represent. X represents _-SO 3 M, -OSO ₃ M or -COOM, M represents H, Na, K, Mg, Ca or ammonium.

Furthermore, Z is preferably a linear or branched alkyl chain having 1 to 8 carbon atoms, more preferably a linear or branched alkyl chain having 1 to 4 carbon atoms. R ¹ and R ² are each independently preferably a linear or branched alkyl chain having 4 to 14 carbon atoms, more preferably a linear or branched alkyl chain having 6 to 12 carbon atoms. is there.

  The top sheet 1 may have a single layer structure or a multilayer structure of two or more layers. Moreover, it may be comprised only from the heat-fusible fiber containing a component (A), (B), and (C), and another 1 type, or 2 or more types of fiber is additionally added with this heat-fusible fiber. May be included. Furthermore, various nonwoven fabrics are mentioned as those containing the heat-fusible fiber, and an air-through nonwoven fabric is preferable from the viewpoint of obtaining a soft touch and high liquid permeability. The “air-through nonwoven fabric” as used herein refers to a nonwoven fabric produced through a process of spraying a fluid of 50 ° C. or higher, for example, gas or water vapor, onto the web or the nonwoven fabric. This means not only non-woven fabrics produced only in this step, but also non-woven fabrics produced by adding this step to non-woven fabrics produced by other methods or non-woven fabrics produced by performing some steps after this step. Moreover, what consists not only of what consists only of an air through nonwoven fabric but the fiber sheet and film materials, such as an air through nonwoven fabric and another nonwoven fabric, is also included.

The fiber treatment agent adheres to the surface of the heat-fusible fiber, and the hydrophilicity of the surface of the fiber is increased as compared with that before attaching the fiber treatment agent. In particular, when the surface sheet is made of a nonwoven fabric and formed with heat treatment, the combination of the components (A), (B) and (C) acts to give a gradient to the hydrophilicity as follows.
That is, since the polyorganosiloxane as the component (A) promotes the penetration of the component (C) having high hydrophobicity and high hydrophilicity into the inside of the fiber, the hydrophilicity of the fiber surface is low by heat treatment. To change. This is because the polysiloxane chain of the polyorganosiloxane and the alkyl chain of the component (C) are incompatible with each other, so that the component (C) is heated inside the hydrophobic heat-fusible fiber, which is easier to adapt. It is thought to occur because it penetrates when melted.
The anionic surfactant represented by the general formula (I) has a bulky alkyl group and can penetrate into the fiber so as to enclose the hydrophilic group. Penetration into is easy to promote.
The polyoxyalkylene-modified polyhydric alcohol fatty acid ester has a structure in which hydrophobic chains are easily arranged radially and easily surround a hydrophilic group. Therefore, compared to a surfactant having a normal linear hydrocarbon chain, Even if the hydrophilicity is high, it easily penetrates into the fiber.
Since alkylhydroxysulfobetaine has both an anionic group and a cationic group, when adsorbed on the fiber surface, the electrostatic repulsion between components (C) is suppressed and the inside of the fiber becomes relatively dense. Easy to penetrate into. Moreover, since it has a hydroxy group between an anionic group and a cationic group, it produces a hydrogen bonding action, and the alkylhydroxysulfobetaine is more easily attracted to each other and is in a dense state. As a result, alkylhydroxysulfobetaine can be adsorbed densely and imparted a high degree of hydrophilicity even with a small addition amount (thin film thickness) with respect to a heat-fusible fiber having a small fiber diameter. Further, since the hydrophilic group is easily accessible, the hydrophilic group is easily taken up by a hydrophobic group and easily penetrates into the fiber.
Regarding the ease of penetration of each component of component (C) into the fiber, the relationship of alkylhydroxysulfobetaine <anionic surfactant represented by general formula (I) <polyoxyalkylene-modified polyhydric alcohol fatty acid ester> There is.

  Thereby, for example, in the process of blowing hot air onto the web, which is one process for producing an air-through nonwoven fabric, the value of the contact angle of the fiber varies depending on the amount of heat as follows. That is, the amount of heat received by the fibers in the web is naturally different between the hot air blowing surface and the opposite surface (net surface). As a result, the amount of heat received differs between the fiber on the hot air blowing surface and the fiber on the opposite surface, and the fiber on the hot air blowing surface has a lower hydrophilicity and a higher contact angle than the fiber on the opposite surface. It becomes. By utilizing this fact, it is possible to provide a hydrophilicity gradient that increases the hydrophilicity from one surface (skin contact surface) side to the other surface (non-skin contact surface) side.

  The above-mentioned gradient of hydrophilicity means a state in which the hydrophilicity on the non-skin contact surface side is higher than the skin contact surface side in the thickness direction of the topsheet 1 unless otherwise specified. This “gradient” broadly includes various modes in which there is a difference in hydrophilicity between the skin contact surface side and the skin contact surface side. An aspect may be sufficient.

  Moreover, if the manufacturing method of the nonwoven fabric which makes the surface sheet 1 is a method which can form the gradient of the hydrophilicity by a heat | fever, it will not be limited to an air through method, Arbitrary methods are employable.

The adhering amount (content) of the fiber treatment agent containing the component (A), the component (B) and the component (C) to the heat-fusible fiber is the total amount of the heat-fusible fiber excluding the fiber treatment agent. As a ratio with respect to mass, from a viewpoint of improving hydrophilicity, 0.1 mass% or more is preferable, 0.15 mass% or more is more preferable, and 0.2 mass% or more is further more preferable. The upper limit is preferably 1.5% by mass or less, more preferably 1.0% by mass or less, and further preferably 0.5% by mass or less from the viewpoint of preventing mechanical contamination. For example, the adhesion amount of the fiber treatment agent to the heat-fusible fiber is preferably 0.1% by mass or more and 1.5% by mass or less as a ratio to the total mass of the heat-fusible fiber excluding the fiber treatment agent, 0.15 mass% or more and 1.0 mass% or less are more preferable, and 0.2 mass% or more and 0.5 mass% or less are more preferable.
Hereinafter, each component will be described.

(Ingredient (A))
As the polyorganosiloxane, any one of a linear one and a crosslinked two-dimensional or three-dimensional network structure can be used. Preferably it is substantially linear. The term “substantially” as used herein may include a polyorganosiloxane having a branched structure by modifying a part of the polyorganosiloxane skeleton or by making a part of the alkyl group a long chain. It means that the content of the polyorganosiloxane is 5% or less.

Specific examples of suitable polyorganosiloxanes are alkylalkoxysilanes, arylalkoxysilanes, alkylhalosiloxane polymers, and cyclic siloxanes. The alkoxy group is typically a methoxy group. 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 further promotes the penetration of the component (C), and from the viewpoint of increasing the contact angle of the fiber surface from the state where the component (C) is adhered by heating, the highly hydrophilic POE This is a concept that does not include a chain-modified polyorganosiloxane.

  The most typical polyorganosiloxanes preferred in the present invention include polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane and the like. Of these, 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, and further preferably 200,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 800,000 or less, and 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 mass average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, and still more preferably 200,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 800,000 or less, and still more preferably 600,000 or less. Another type has a mass average molecular weight of preferably less than 100,000, more preferably 50,000 or less, more preferably 35,000 or less, and particularly preferably 20,000 or less. The lower limit is preferably 2000 or more, more preferably 3000 or more, and still more preferably 5000 or more. Moreover, the preferable compounding ratio of the polyorganosiloxane having a mass average molecular weight of 100,000 or more and the polyorganosiloxane having a mass average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1, more preferably 1. : 5 to 2: 1.

The mass average molecular weight of the polyorganosiloxane is measured using GPC (manufactured by Tosoh Corporation, trade name CCPD). 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

  As the component (A), any one of the above-mentioned agents can be used alone or in admixture of two or more.

  The content ratio of the polyorganosiloxane in the fiber treatment agent attached to the fibers 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 of making it easy to absorb the liquid from the 1st layer 1, 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.

  Furthermore, the content of the polyorganosiloxane in the fiber treatment agent is within the above range from the viewpoint of preventing the hydrophilicity of the surface sheet from being excessively lowered, that is, from the viewpoint of suppressing the amount of excretory liquid adhering to the skin. It is preferable that

  A commercial item can also be used as polyorganosiloxane as a component (A). For example, “KF-96H-1 million Cs” manufactured by Shin-Etsu Chemical Co., Ltd., “SH200 Fluid 1000000 Cs” manufactured by Toray Dow Corning Co., Ltd., and those containing two types of polyorganosiloxane include Shin-Etsu Chemical Co., Ltd. “KM-903” manufactured by Co., Ltd. or “BY22-060” manufactured by Toray Dow Corning Co., Ltd. can be used.

In addition, unless otherwise explained, the “fiber treatment agent” used as a reference for the content of the component of the fiber treatment agent, such as the component (A) and the component (B) and the component (C) described later, "Fiber treatment agent attached", not the fiber treatment agent before adhering to the surface sheet. When the fiber treatment agent is attached to the nonwoven fabric, since the fiber treatment agent is usually diluted with a suitable solvent such as water, the content of the component of the fiber treatment agent, for example, in the fiber treatment agent of component (A) The content of can be based on the total mass of the diluted fiber treatment agent.
The above analysis method is similarly applied to other components.

(Ingredient (B))
The phosphoric acid ester type anionic surfactant as component (B) improves properties such as carding ability of the raw cotton and uniformity of the web, thereby preventing an increase in the productivity of the nonwoven fabric and a reduction in quality. For this purpose, it is added to the fiber treatment agent S1. Specific examples include alkyl ether phosphates, dialkyl phosphates, and alkyl phosphates. Of these, alkyl phosphates are preferred from the viewpoint of processability.

  Various alkyl ether phosphates can be used without particular limitation. For example, those having saturated carbon chains such as stearyl ether phosphate, myristyl ether phosphate, lauryl ether phosphate, palmityl ether phosphate, oleyl ether phosphate, palmitoleyl ether phosphate, etc. 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 a carbon chain of 16 or more and 18 or less. Examples of the salt of alkyl ether phosphate 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.

  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 those having 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 a carbon chain of 16 or more and 18 or less. 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 content ratio of the component (B) in the fiber treatment agent attached to the fibers is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of card machine passability and web uniformity. . Further, from the viewpoint of not preventing the fiber from being hydrophobized by polyorganosiloxane due to heat treatment, the content is preferably 30% by mass or less, more preferably 25% by mass or less.

(Ingredient (C))
(I) When component (C) is an anionic surfactant represented by the general formula (I):
The anionic surfactant represented by the general formula (I) refers to a component that does not contain the phosphate ester type anionic surfactant that is the component (B). Moreover, a component (C) 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 (I) is —SO ₃ M, that is, the hydrophilic group is a sulfo group or a salt thereof, include 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 dialkylsulfonic 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 a sulfo group or a salt thereof include the following anionic surfactants.

Examples of the anionic surfactant in which X in the general formula (I) is -OSO ₃ M, that is, the hydrophilic group is a sulfate group or a salt thereof, include dialkyl sulfates. Specific examples thereof include compounds obtained by sulfating alcohols having a branched chain such as 2-ethylhexyl sulfate sodium salt and 2-hexyldecyl sulfate sodium salt, polyoxyethylene sulfate 2-hexyldecyl sulfate and polyoxyethylene sulfate 2- A compound in which a POE chain is introduced between an alcohol having a branched chain such as hexyldecyl and a sulfate group, or 12-sulfate stearic acid 1-methyl ester (or amide) 3-sulfate hexanoic acid 1-methyl ester (or And a compound obtained by sulfating a hydroxy fatty acid ester (or amide) such as amide).

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

  Examples of the anionic surfactant in which X in the general formula (I) is —COOM, that is, the hydrophilic group is a carboxy group or a salt thereof, include dialkyl carboxylic acids. Specific examples thereof include compounds in which the hydroxy moiety of hydroxy fatty acid such as 11-ethoxyheptadecane carboxylic acid sodium salt and 2-ethoxypentacarboxylic acid sodium salt is alkoxylated and the fatty acid moiety is sodiumated, and amino acids such as sarcosine and glycine. Examples thereof include a compound obtained by reacting an amino group with an alkoxylated hydroxy fatty acid chloride to sodiumize the carboxylic acid in the amino acid part, a compound obtained by reacting an amino group of arginic acid with a fatty acid chloride, and the like.

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

  As described above, by using the fiber treatment agent in which the component (C) and the component (A) are blended, the heat-fusible fiber treated with this fiber treatment agent is a fiber whose hydrophilicity is likely to be lowered by heat treatment. It becomes. The reason is that the above-described polyorganosiloxane further promotes the penetration of an anionic surfactant having two or more alkyl chains into the fiber. As a result, the hydrophilicity of the fiber surface tends to decrease due to heat treatment. This is because the polysiloxane chain of the polyorganosiloxane and the alkyl chain of the anionic surfactant are incompatible with each other, and when the fiber is heated and melted into the more easily adaptable hydrophobic heat-fusible fiber, Presumed to occur due to penetration of anionic surfactant.

  The content ratio of the component (C) in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass with respect to the total mass of the fiber treatment agent, from the viewpoint of increasing the change in hydrophilicity due to heat treatment. That's it. Moreover, when hydrophilicity becomes high too much, it is 20 mass% or less from a viewpoint which it becomes easy to have a liquid and impairs dryness, More preferably, it is 13 mass% or less. The content 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 of the polyorganosiloxane of the component (A) and the anionic surfactant represented by the general formula (I) of the component (C) in the fiber treatment agent is a mass ratio, preferably 1: 1. 6 to 1: 0.6, more preferably 1: 1.3 to 1: 0.9. In the fiber treatment agent, the content ratio of the polyorganosiloxane of component (A) to the phosphate ester type anionic surfactant of component (B) is a mass ratio, preferably 1: 5 to 10: 1, more preferably 1: 2 to 3: 1.

(Ii) When component (C) is a polyoxyalkylene-modified polyhydric alcohol fatty acid ester:
The polyoxyalkylene-modified polyhydric alcohol fatty acid ester makes the decrease in hydrophilicity due to heat treatment during the production of the nonwoven fabric forming the top sheet 1 more remarkable, that is, significantly improves the hydrophilicity of a desired portion in the nonwoven fabric. It is a kind of nonionic surfactant that is added to the fiber treatment agent for the purpose of lowering. The polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a kind of polyhydric alcohol fatty acid ester obtained by esterifying a hydroxyl group of a polyhydric alcohol with a fatty acid, and is a modified product obtained by adding an alkylene oxide to the polyhydric alcohol fatty acid ester. The polyoxyalkylene-modified polyhydric alcohol fatty acid ester can be produced according to a conventional method, and can be produced, for example, according to Japanese Patent Application Laid-Open No. 2007-91852.

  Examples of the polyhydric alcohol that is one of the raw materials of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester (or polyhydric alcohol fatty acid ester) include, for example, ethylene glycol, diethylene glycol, polyethylene glycol (molecular weight 200 to 11000), propylene glycol, di Propylene glycol, polypropylene glycol (molecular weight 250-4000), 1,3-butylene glycol, glycerin, polyglycerin (degree of polymerization 2-30), erythritol, xylitol, sorbitol, mannitol, inositol, sorbitan, sorbide, sucrose, trehalose, Examples include erulose, lactosucrose, cyclodextrin, maltitol, lactitol, palatinit, panitol, and reduced starch syrup. Preferred are polyethylene glycol, glycerin, erythritol, sorbitol, sorbitan, sorbide, and sucrose, and particularly preferred are sorbitol, sorbitan, and sorbide.

  Examples of the fatty acid that is another raw material of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester (or polyhydric alcohol fatty acid ester) include, for example, a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, and these as a main component. Mixed fatty acids or branched chain fatty acids having 8 to 36 carbon atoms. The fatty acid may partially contain a hydroxyl group. Specifically, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid , 2-ethylhexylic acid, isostearic acid, and the like, and coconut oil fatty acid and beef tallow fatty acid which are naturally derived mixed fatty acids may be used, preferably fatty acids having 8 to 18 carbon atoms, particularly preferably dodecanoic acid, octadecane. Acid, cis-9-octadecenoic acid.

  The main component of the polyhydric alcohol fatty acid ester constituting the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is not to increase the shape of the molecule linearly when the hydrophobic chain is enlarged and the hydrophobicity is increased. From the viewpoint of increasing the dimension dimensionally, it is preferable to use a trivalent or higher alcohol esterified product with an alcohol component esterification rate of 90% or higher from the viewpoint of obtaining a shape that can be easily taken into the fiber. Here, the main component is the most abundant component in the polyhydric alcohol fatty acid ester, and is preferably contained in an amount of 50% by mass or more based on the total mass of the polyhydric alcohol fatty acid ester. For example, examples of the trivalent alcohol include glycerin, examples of the tetravalent alcohol include erythritol, and examples of the pentavalent alcohol include xylitol.

  Particularly preferred as the polyhydric alcohol fatty acid ester constituting the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is castor oil (hardened castor oil). Castor oil is a glycerin fatty acid ester derived from the seeds of castor, which is a plant belonging to the family Dromeliaceae, and about 90% of the constituent fatty acid is ricinoleic acid. That is, the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is preferably an ester oil of glycerin and a fatty acid mainly composed of ricinoleic acid.

  In the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, examples of the alkylene oxide added to the polyhydric alcohol fatty acid ester include ethylene oxide, propylene oxide, butylene oxide, and the like. Particularly preferred as the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a polyoxyethylene (POE) -modified polyhydric alcohol fatty acid ester in which the alkylene oxide added to the polyhydric alcohol fatty acid ester is ethylene oxide, and particularly preferred are Polyhydric alcohol fatty acid ester is POE-modified castor oil (POE-modified hardened castor oil), which is castor oil (hardened castor oil).

  In the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, the number of moles of alkylene oxide added to the polyhydric alcohol fatty acid ester is from the viewpoint of improving the liquid absorption performance of the hydrophilic nonwoven fabric (reducing the amount of liquid remaining and reducing the amount of liquid flow). , Preferably exceeding 20 mol, particularly preferably 40 mol or more. However, if the number of added moles of alkylene oxide is too large, the hydrophilicity of the hydrophilic non-woven fabric will increase too much.For example, when the hydrophilic non-woven fabric is used as a surface sheet in an absorbent article, the amount of residual liquid will increase. Since there exists a possibility that it may connect, this addition mole number becomes like this. Preferably it is 80 mol or less, More preferably, it is 60 mol or less.

  The content of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester in the fiber treatment agent increases the hydrophilicity of the hydrophilic non-woven fabric so that the effect of lowering the hydrophilicity due to heat treatment during the production of the hydrophilic non-woven fabric is significantly manifested. From the viewpoint of suppressing the increase in the remaining amount of liquid due to strong hydrophilization, preferably 5% by mass or more, more preferably 10% by mass or more with respect to the total mass of the fiber treatment agent. Preferably it is 20 mass% or less with respect to the total mass, More preferably, it is 15 mass% or less.

  In the fiber treatment agent, the content ratio of the polyorganosiloxane of the component (A) and the polyoxyalkylene-modified polyhydric alcohol fatty acid ester of the component (C) is a mass ratio, preferably 1: 2 to 3: 1. More preferably, it is 1: 1 to 2: 1. In this case, the content ratio of the polyorganosiloxane of the component (A) and the phosphate ester type anionic surfactant of the component (B) is as described above.

(Iii) When component (C) is alkylhydroxysulfobetaine:
Alkylhydroxysulfobetaine has the property of adsorbing closely to the fiber surface as described above. For this reason, alkylhydroxysulfobetaine can realize high hydrophilicity, which is difficult to obtain with a normal fiber treatment agent, for fibers having a reduced fiber diameter.
Specifically, alkylhydroxysulfobetaine is a surfactant represented by the following general formula (II).

In the formula, R ¹ represents an alkyl group having 6 to 24 carbon atoms. Among these, in addition to the dense adsorption of sulfobetaine groups, the number of carbon atoms is more preferably 8 or more, from the viewpoint of forming a denser adsorption surface on the fiber surface by hydrophobic interaction with hydrocarbon groups. Is more preferable, 22 or less is more preferable, and 18 or less is more preferable.

  More specifically, lauryl hydroxysulfobetaine, myristyl hydroxysulfobetaine, palmityl hydroxysulfobetaine, and stearyl hydroxysulfobetaine can be used.

  As alkylhydroxysulfobetaine, any one of the above-mentioned agents can be used alone or in admixture of two or more.

  The content ratio of the alkylhydroxysulfobetaine in the fiber treatment agent is preferably less than 10% by mass, more preferably less than 9% by mass, and still more preferably less than 8% by mass with respect to the total mass of the fiber treatment agent. It is. Thereby, the hydrophilicity gradient by the said component (A) is easy to be formed more clearly, and the low liquid remaining property and low liquid return property of a nonwoven fabric can be maintained. The lower limit is preferably 3% by mass or more, more preferably 5% by mass or more, from the viewpoint of imparting sufficient hydrophilicity to the fiber.

  The content ratio of the polyorganosiloxane of the component (A) and the alkylhydroxysulfobetaine of the component (C) in the fiber treatment agent is a mass ratio, preferably 1: 1.6 to 1: 0.6. Preferably it is 1: 1.3 to 1: 0.9. In this case, the content ratio of the polyorganosiloxane of component (A) and the phosphate ester type anionic surfactant of component (B) is as described above.

(Other ingredients)
The fiber treatment agent S1 attached to the heat-fusible fiber of the topsheet 1 may contain other components in addition to the components (A), (B) and (C) described above. As other components, 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 zwitterionic surfactants include alkylbetaines. Among alkylbetaines, alkyl (C1 to 30) dimethylbetaine, alkyl (C1 to 30) amide alkyl (C1 to 4) dimethylbetaine, alkyl (C1 to 30) dihydroxyalkyl (C1-C30) Betaine-type amphoteric surfactant such as betaine, sulfobetaine-type amphoteric surfactant, alanine type [alkyl (C1-C30) aminopropionic acid type, alkyl (carbon number) 1 to 30) iminodipropionic acid type, etc.] amphoteric surfactants, glycine types such as alkylbetaines [alkyl (carbon number of 1 to 30) aminoacetic acid type, etc.] amino acid type amphoteric surfactants such as amphoteric surfactants Aminosulfonic acid type amphoteric surfactants such as alkyl (1 to 30 carbon atoms) taurine type It is below. Among them, alkyl (1 to 30 carbon atoms) dimethyl betaine is preferable, and alkyl dimethyl betaine having 16 to 22 carbon atoms (for example, stearyl) is particularly preferable.

  Examples of nonionic surfactants include polyalcohol 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 carbon atoms of fatty acid). 60 or less), polyoxyalkylene (addition mole number 2 or more and 60 or less) alkyl (carbon number 8 or more and 22 or less) amide, polyoxyalkylene (addition mole number 2 or more and 60 or less) alkyl (carbon number 8 or more and 22 or less) ether , Polyoxyalkylene-modified silicone, amino-modified silicone, polyoxyethylene alkylamide, polyoxyethylene, polyoxypropylene-modified silicone, and the like. Of these, glycerin fatty acid ester is preferable, and glycerin monocaprylate is more preferable.

  A treatment agent such as an anti-sticking agent such as modified silicone may be added to the fiber treatment agent.

(Fiber treated with fiber treatment agent)
The heat-fusible fiber constituting the nonwoven fabric constituting the top sheet 1 is treated with a fiber treatment agent, and at least the fiber treatment agent adheres to the surface. As the heat-fusible fiber before adhering, the fiber used for the nonwoven fabric can be used without particular limitation. For example, 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, a hollow fiber, and the like can be given.

  It is preferable that at least the surface of the heat-fusible fiber used in the present invention is formed of a polyolefin resin. If the surface of the heat-fusible fiber, which is a constituent fiber of the hydrophilic nonwoven fabric, is formed of a polyolefin resin, the fiber surface is melted by heat treatment during the manufacture of the hydrophilic nonwoven fabric, and the fiber treatment agent penetrates into the fiber. As a result, the hydrophilicity of a desired portion can be effectively reduced. Examples of the polyolefin-based resin that forms the surface of the heat-fusible fiber include polyethylene and polypropylene, and one of these can be used alone or two or more of them can be used in combination.

  The heat-fusible fiber used in the present invention is preferably a heat-fusible core-sheath composite fiber. The heat-fusible core-sheath type composite fiber subjected to the fiber treatment is a heat-sealable and core-sheath type composite fiber similar to the heat-fusible core-sheath type composite fiber before attaching the fiber treatment agent. is there. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or an irregular shape, and is preferably a concentric core-sheath type.

As the heat-fusible fiber to which the fiber treatment agent is attached, various types of fibers that do not inhibit the penetration of the components in the fiber treatment agent into the fiber can be used. For example, “core-sheath type composite fiber having a sheath part containing polyethylene resin and a core part made of a resin component having a melting point higher than that of the polyethylene resin (hereinafter referred to as“ core-sheath type composite fiber ”) Fiber S) ”. Examples of the polyethylene resin constituting the sheath of the core-sheath type composite fiber S include low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and the density is 0.935 g. It is preferably a high-density polyethylene that is not less than / cm ^{3 and not} more than 0.965 g / cm ³ . The resin component constituting the sheath portion of the core-sheath type composite fiber S is preferably a polyethylene resin alone. However, the present invention is not limited to this, and a blend of polyethylene resin and another resin may be used. 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 a polyethylene resin, and it is preferable that 70 mass% or more and 100 mass% or less are especially polyethylene resins. Further, the polyethylene resin constituting the sheath portion of the core-sheath type composite fiber S 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 S plays a role of providing the heat-fusible core-sheath type composite fiber with heat-fusibility and taking in the fiber treatment agent described above during heat treatment. Thereby, the penetration | infiltration of the component in the fiber processing agent mentioned above to the inside of a fiber is accelerated | stimulated, and it becomes further easy to form the hydrophilization gradient in a surface sheet. However, the heat-fusible fiber used for the top sheet is not limited to the core-sheath type composite fiber S. For example, the sheath may be polypropylene (PP) or copolymer polyester depending on the resin component of the core.
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 S, 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 melting point when the resin component constituting the core is a blend of a plurality of types of resins is the melting point of the resin having the highest melting point.

  The heat-fusible fiber to which the fiber treatment agent is attached is preferably a fiber whose length is increased by heating (hereinafter also referred to as heat-extensible fiber). 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, a state where it can be extended by heating, or both. When heat-extensible fibers are heated, the fiber treatment agent on the surface is easily taken into the interior, 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 fiber is a composite fiber (hereinafter also referred to as a heat-extensible composite fiber) having a first resin component that constitutes a core part and a second resin component that constitutes a sheath part. The second resin component has a lower melting point or softening point than the first resin component, and at least part of the fiber surface is continuously present in the length direction. 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 are defined as temperatures measured by the following method using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.). That is, thermal analysis of a finely cut fiber sample (sample mass 2 mg) is performed at a heating rate of 10 ° C./min, the melting peak temperature of each resin is measured, and the melting peak temperature is defined. 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-extensible 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, and still more preferably 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% or more and 20% or less 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). More preferably, it is 3% or more and 20% or less, and further preferably 5.0% or more and 20% or less. 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 specific mass ratio between the first resin component and the second resin component in the heat-extensible composite fiber is 10:90 to 90:10, particularly 20:80 to 80:20, especially 50:50 to 70: in mass ratio. 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 mm 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 the nonwoven fabric is used 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 size of 10 μm to 35 μm, particularly 15 μm 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 Application Laid-Open No. 2005-350836, Japanese Patent Application Laid-Open No. 2007-303035, Japanese Patent Application Laid-Open No. 2007-204899, The fibers described in JP 2007-204901 A and JP 2007-204902 A can also be used.

  Moreover, you may use the fiber which contained the titanium oxide mentioned above from a viewpoint of raising the whiteness of the surface sheet 1 and improving the concealment property of redness, such as menstrual blood.

(Treatment of fiber with fiber treatment agent)
As a method for attaching the above-mentioned fiber treatment agent to the surface of the fiber, various known methods can be employed without particular limitation. For example, application by spraying, application by slot coater, application by roll transfer, immersion in a hydrophilic oil, and the like can be mentioned. These treatments may be performed on the fibers before being formed into a web, or may be performed after the fibers are formed into a web by various methods. The fiber having the fiber treatment agent attached to the surface thereof is dried at a temperature sufficiently lower than the melting point of the ethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing dryer.

  The non-woven fabric forming the top sheet 1 may be a mixture of heat-extensible fibers and non-heat-extensible fibers as heat-fusible fibers. 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 term “stretching treatment” as used herein refers to a stretching operation at a stretching ratio of 2 to 6 times. The mixing ratio of the heat-extensible fibers and the non-heat-extensible fibers is, by mass ratio, preferably 1: 9 to 9: 1 for the former: latter and more preferably 4: 6 to 6: 4. Thereby, it becomes easier to recover the bulk of the nonwoven fabric with hot air, and it is possible to obtain a nonwoven fabric with better touch and dryness than using each fiber alone.

  Thus, the nonwoven fabric which has several parts from which hydrophilicity mutually differs is obtained by heat-processing to the web and nonwoven fabric manufactured using the heat-fusible fiber.

  The heat-fusible fiber preferably has a water contact angle of 90 degrees or less with respect to the fiber taken out from the nonwoven fabric. When the hydrophilicity of the surface is further increased by the fiber treatment agent, it becomes possible to form a plurality of regions having greatly different hydrophilicities on the fiber itself or a nonwoven fabric produced using the fiber. From the same point of view, the heat-fusible core-sheath conjugate fiber taken out from the nonwoven fabric has a contact angle with water of preferably 90 degrees or less, more preferably 85 degrees or less, and is too hydrophilic. Since it becomes easy to have a liquid, it is preferably 60 degrees or more, more preferably 65 degrees or more. Moreover, it is preferably 65 degrees or more and 85 degrees or less, and more preferably 70 degrees or more and 80 degrees or less. A decrease in hydrophilicity is synonymous with an increase in contact angle. This contact angle can be obtained by the aforementioned (contact angle measurement method).

  As an embodiment of the surface sheet that takes advantage of the bulkiness by the combination of the above-described heat-extensible fibers and non-heat-extensible heat-fusible fibers and the bulkiness recoverability by hot air after loading, for example, FIG. There are those shown in i) and (ii).

  As shown in FIGS. 2 (i) and (ii), the nonwoven fabric 20 constituting the topsheet 1 has a concavo-convex surface 51 having a concavo-convex shape on the first surface side (front surface side), and the second surface side (back surface). The flat surface 52 is flat or has a small degree of unevenness compared to the uneven surface. That is, the uneven surface 51 is on the first layer 1 side, and the flat surface 52 is on the second layer 2 side. The thick portion 59 and the thin portion 58 in the nonwoven fabric 20 correspond to the positions of the convex portions 69 and the concave portions 68 formed on the concave and convex surface 51 of the nonwoven fabric 20. The recess 68 includes a first linear recess 68A extending in parallel with each other and a second linear recess 68B extending in parallel with each other, and the first linear recess 68A and the second linear recess 68B. And intersect at a predetermined angle. The convex portion 69 is formed in a rhomboid closed region surrounded by the concave portion 69.

  The top portion T of the convex portion 69 is a top portion formed on the uneven surface 51 of the nonwoven fabric by the thick portion 59. In the nonwoven fabric 20, as described above, the hydrophilicity of the thin portion 58 and the portion on the flat surface 52 side is higher than that of the top portion T. Thereby, when a liquid enters from the uneven surface 51 side, the liquid easily escapes to the flat surface 52 side, and the remaining liquid in the nonwoven fabric 20 decreases. Further, it is preferable that the hydrophilicity gradually increases from the top portion T of the thick portion 59 toward the thin portion (embossed portion) 58 and the portion on the flat surface 52 side.

  The uneven surface 51 of the nonwoven fabric 1 is directed to the embossing roll side during embossing, and is directed to the side opposite to the net surface (breathable support) when hot air treatment is performed by an air-through method, and directly blows hot air. It is a side surface. Therefore, when a heat-extensible conjugate fiber is used as the constituent fiber of the nonwoven fabric, the heat-extensible conjugate fiber extends more greatly on the uneven surface 51 than on the flat surface 52. Therefore, the fiber diameter in the surface of the flat surface 52 becomes larger than the fiber diameter in the surface of the uneven surface 51 in the heat-extensible composite fiber. Further, the hydrophilicity of the thick portion 59 is lower on the uneven surface 51 side than on the flat surface 52 side.

  The difference between the contact angle of water with respect to the fibers contained in the top portion T and the contact angle of water with respect to the fibers contained in the back surface TR (top portion) from the viewpoint of smoother liquid permeation from the top T side to the back surface TR side. P1-back surface P2) is preferably 3 ° or more, particularly preferably 5 ° or more, and preferably 25 ° or less, particularly preferably 20 ° or less. For example, the difference is preferably 3 ° to 25 °, more preferably 5 ° to 20 °. In order to produce a hydrophilic nonwoven fabric in which the difference in the contact angle of the constituent fibers between the top T and the back surface TR is within the above range, the fiber treatment agent is used, and the hot air blowing conditions in the heat treatment by the air-through method described above, That is, the temperature and amount of hot air may be appropriately controlled.

  In the production of the nonwoven fabric 20, the temperature applied to the web during embossing is from the viewpoint of suppressing changes in the hydrophilicity in either the embossed part and its vicinity (peripheral part) or the embossed part and its vicinity (peripheral part). It is preferable that the temperature is 20 ° C. or more lower than the melting point of the polyethylene resin constituting the sheath part and less than the melting point of the resin component constituting the core part. On the other hand, the temperature applied during the hot air treatment is at least 10 ° C. lower than the melting point of the polyethylene resin, in particular, more than the melting point of the polyethylene resin, and more preferably the melting point of the polyethylene resin +5 from the viewpoint of surely causing a change in hydrophilicity. It is preferable that the temperature is not lower than ° C.

The basis weight of the nonwoven fabric 20 is preferably 10 g / m ² or more and 80 g / m ² or less, particularly preferably 15 g / m ² or more and 60 g / m ² or less. The thickness of the convex portion 69 (thick portion 59) in the nonwoven fabric 20 is preferably 0.5 mm or more and 3 mm or less, particularly 0.7 mm or more and 3 mm or less in a state after bulk recovery by hot air. On the other hand, the thickness of the recess 68 (thin portion 58) is preferably 0.01 mm or more and 0.4 mm or less, particularly preferably 0.02 mm or more and 0.2 mm or less. The thickness of the recess 68 is not substantially changed before and after the hot air is blown. The thickness of the convex part 69 and the concave part 68 is measured by observing the longitudinal section of the nonwoven fabric 20. First, the nonwoven fabric is cut into a size of 100 mm × 100 mm, and a measurement piece is collected. A plate of 12.5 g (diameter 56.4 mm) is placed on the measurement piece, and a load of 49 Pa is applied. Under this condition, the longitudinal section of the nonwoven fabric is observed with a microscope (VHX-1000, manufactured by Keyence Corporation), and the thicknesses of the convex portions 69 and the concave portions 68 are measured. In addition, when the convex part (thick part) and the concave part (thin part) are formed in the nonwoven fabric, the “thickness of the nonwoven fabric” refers to the thickness of the convex part (thick part).

The area ratio between the recesses 68 and the protrusions 69 in the nonwoven fabric 20 is expressed by an embossing rate (embossed area ratio, that is, the ratio of the total area of the recesses with respect to the entire nonwoven fabric 1), and affects the bulkiness and strength of the nonwoven fabric 1. give. From these viewpoints, the embossing rate in the nonwoven fabric 1 is preferably 5% to 35%, particularly preferably 10% to 25%. The embossing rate is measured by the following method. First, using a microscope (manufactured by Keyence Co., Ltd., VHX-1000), obtain a surface enlarged photograph of the nonwoven fabric 1, adjust the scale to this surface enlarged photograph, and measure the dimensions of the embossed part in the entire area T of the measurement part, An embossed area U is calculated.
The embossing rate can be calculated by the formula (U / T) × 100.

  The embossed part formation pattern in the nonwoven fabric 20 can be an arbitrary pattern such as a multi-row stripe, dot, checkered, or spiral, instead of the lattice shown in FIG. The shape of each point in the case of a dot shape may be a circle, an ellipse, a triangle, a quadrangle, a hexagon, a heart shape, or an arbitrary shape. Moreover, you may employ | adopt the shape which makes a square or rectangular lattice shape, or a tortoiseshell pattern.

As a material of the constituent members of the napkin 10 of the present embodiment, those employed for this type of article can be used without particular limitation. For example, the raw material of the absorber 3, the second sheet 4, and the surface sheet 1 mentioned above is mentioned.
Moreover, as a raw material of the back surface sheet 2, a moisture-permeable film alone, a pasting of a film and a nonwoven fabric, or a water-repellent nonwoven fabric (such as SMS or SMMS) can be used. It is most preferable to use a moisture permeable film alone as a leak-proof material from the viewpoint of cost and matching with an anti-displacement adhesive. As the film material in this case, a film obtained by melt-kneading a thermoplastic resin and an inorganic filler that is not compatible with the thermoplastic resin and extruding the film to a predetermined size to make fine holes, or essentially moisture The non-porous film which is highly compatible and can discharge water vapor, such as a permeable membrane.

  The sanitary napkin 10 of the embodiment is not limited to the above-described member configuration and shape as long as the sanitary napkin 10 includes the absorber 3 having the density and the second sheet 4 having the capillary force. For example, the absorbent article of the present invention may be a combination of grooves separated into a plurality of leak-proof grooves 5 instead of annular. Further, the rear portion R may have a rear flap portion that extends long so as to cover the wearer's buttocks, and the crotch portion C has a pair of wing portions that are fixed to the crotch of the underwear. May be. Furthermore, the water-repellent side sheet | seat which prevents the side leakage of excretion liquid may be distribute | arranged on the both sides of the vertical direction (Y direction) on the surface sheet 1. FIG. Moreover, you may have the adhesion part fixed to underwear in the non-skin contact surface side of the back surface sheet 2, and also there may be a peeling sheet etc. which covers this adhesion part so that peeling is possible.

  Moreover, the absorbent article of this invention is not limited to said sanitary napkin, It can be set as the various thing which absorbs and retains excretory fluid. For example, a panty liner, an incontinence pad, a disposable diaper, a urine collecting pad, or the like may be used.

  This invention discloses the following absorbent articles further regarding embodiment mentioned above.

<1>
An absorbent article comprising a top sheet, a back sheet, and a liquid-retaining absorbent disposed between the top sheet and the back sheet, wherein a second sheet is disposed between the top sheet and the absorbent The absorbent article has a density higher than 0.12 g / cm ³ and the second sheet has a capillary force of 1.5 × 10 ³ N or more.

<2>
Density of the absorber, 0.10 g / cm ³ or more preferably, 0.12 g / cm ³ or more, and also preferably from 3.0 g / cm ³ or less, more preferably 2.75 g / cm ³ or less The absorbent article according to <1>, further preferably 2.5 g / cm ³ or less.
<3>
The absorbent article according to <1> or <2>, wherein the absorbent body has a thickness of a liquid absorbing portion at a width center of the absorbent article of 3.2 mm or less.
<4>
The absorbent article according to any one of <1> to <3>, wherein the absorption rate of the absorber is 14.5 seconds or more.

（式中、Ｍｅはメチル基、Ｒはメチレン基、プロピレン基、ブチレン基、Ｎ-（アミノエチル）メチルイミノ基、又はＮ-（アミノプロピル）プロピルイミノ基などを表し、Ｘはポリオキシアルキレン基を表す。上記のポリオキシアルキレン基としては、ポリオキシエチレン基、ポリオキシプロピレン基、ポリオキシブチレン基、及びこれ等の構成モノマーが共重合されたものなどが挙げられる。）
＜９＞
前記ポリオキシアルキレン変性シリコーンが、ポリオキシエチレン（ＰＯＥ）変性及びポリオキシプロピレン（ＰＯＰ）変性のいずれか又は双方の変性基を有することが好ましく、ポリオキシエチレン（ＰＯＥ）ポリオキシプロピレン（ＰＯＰ）変性シリコーン及びポリオキシエチレン変性シリコーンからなる群から選ばれる少なくとも１種であることがより好ましい、前記＜６＞〜＜８＞のいずれか１に記載の吸収性物品。
＜１０＞
前記セカンドシートに含まれる繊維が、該繊維の質量割合で、酸化チタンを０．１５質量％を超えて含有しており、該含有量は０．５質量％以上がより好ましく、１．０質量％以上が更に好ましく、また、５質量％以下が好ましく、４．５質量％以下がより好ましい、前記＜１＞〜＜９＞のいずれか１に記載の吸収性物品。
＜１１＞
前記セカンドシートの毛管力が１．５×１０^３Ｎ以上３．０×１０^３Ｎ以下である前記＜１＞〜＜６＞のいずれか１に記載の吸収性物品。
＜１２＞
前記セカンドシートの毛管力が、１．６×１０^３Ｎ以上が好ましく、１．７×１０^３Ｎ以上がより好ましく、また、３．０×１０^３Ｎ以下が好ましく、２．９×１０^３Ｎ以下がより好ましく、２．０×１０^３Ｎ以下が更に好ましい、前記＜１＞〜＜１１＞のいずれか１に記載の吸収性物品。
＜１３＞
前記セカンドシートの繊維間距離は、８０μｍ以下が好ましく、７５μｍ以下がより好ましく、７０μｍ以下が更に好ましく、また、３５μｍ以上が好ましく、４０μｍ以上がより好ましく、４５μｍ以上が更に好まし、前記＜１＞〜＜１２＞のいずれか１に記載の吸収性物品。
＜１４＞
前記セカンドシートに用いられる繊維の繊度は、３．３ｄｔｅｘ以下が好ましく、２．７ｄｔｅｘ以下がより好ましく、２．２ｄｔｅｘ以下が更に好ましく、また、１．０ｄｔｅｘ以上が好ましく、１．２ｄｔｅｘ以上がより好ましく、１．５ｄｔｅｘ以上が更に好まし、前記＜１＞〜＜１３＞のいずれか１に記載の吸収性物品。
＜１５＞
前記セカンドシートが、ＨＬＢが５以上のポリオキシアルキレン変性シリコーンを有し、該ＨＬＢは６以上がより好ましく、７以上が更に好ましく、また、１６以下が好ましく、１５．５以下がより好ましく、１５以下が更に好ましい、前記＜１＞〜＜１４＞のいずれか１に記載の吸収性物品。
＜１６＞
前記セカンドシートがポリオキシアルキレン変性シリコーンを有し、該ポリオキシアルキレン変性シリコーンが、ポリオキシエチレン変性及びポリオキシプロピレン変性から選ばれる少なくとも１の変性基を有する前記＜１＞〜＜１５＞のいずれか１に記載の吸収性物品。 <5>
The absorbent sheet according to any one of <1> to <4>, wherein the second sheet is disposed in contact with an absorbent body.
<6>
The fibers contained in the second sheet have a fiber treatment agent, and the polyoxyalkylene-modified silicone exceeds 10% by mass with respect to the total mass of the fiber treatment agent. The absorbent article according to any one of 5>.
<7>
The polyoxyalkylene-modified silicone is more preferably contained in an amount of 12% by mass or more, more preferably 14% by mass or more, based on the mass of the fiber treatment agent attached to the fiber. The absorbent article as described in>.
<8>
The absorbent article according to <6> or <7>, wherein the polyoxyalkylene-modified silicone is represented by the following general formula (M).

(In the formula, Me represents a methyl group, R represents a methylene group, a propylene group, a butylene group, an N- (aminoethyl) methylimino group, an N- (aminopropyl) propylimino group, etc., and X represents a polyoxyalkylene group) Examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and those obtained by copolymerizing these constituent monomers.
<9>
The polyoxyalkylene-modified silicone preferably has a modification group of either or both of polyoxyethylene (POE) modification and polyoxypropylene (POP) modification, and polyoxyethylene (POE) polyoxypropylene (POP) modification. The absorbent article according to any one of <6> to <8>, more preferably at least one selected from the group consisting of silicone and polyoxyethylene-modified silicone.
<10>
The fiber contained in the second sheet contains titanium oxide in a mass ratio of more than 0.15% by mass, and the content is more preferably 0.5% by mass or more, and 1.0% by mass. % Or more is more preferable, 5 mass% or less is preferable, and 4.5 mass% or less is more preferable, Absorbent article in any one of said <1>-<9>.
<11>
The absorbent article according to any one of <1> to <6>, wherein the capillary force of the second sheet is 1.5 × 10 ³ N or more and 3.0 × 10 ³ N or less.
<12>
The capillary force of the second sheet is preferably 1.6 × 10 ³ N or more, more preferably 1.7 × 10 ³ N or more, and preferably 3.0 × 10 ³ N or less, and 2.9 × 10 ^3. more preferably not more than N, 2.0 × more preferably not more than 10 ³ N, the <1> to absorbent article according to any one of <11>.
<13>
The inter-fiber distance of the second sheet is preferably 80 μm or less, more preferably 75 μm or less, further preferably 70 μm or less, more preferably 35 μm or more, more preferably 40 μm or more, and further preferably 45 μm or more, <1> The absorbent article according to any one of ~ <12>.
<14>
The fineness of the fiber used for the second sheet is preferably 3.3 dtex or less, more preferably 2.7 dtex or less, further preferably 2.2 dtex or less, more preferably 1.0 dtex or more, and more preferably 1.2 dtex or more. 1.5 dtex or more is further preferable, The absorbent article according to any one of <1> to <13>.
<15>
The second sheet has a polyoxyalkylene-modified silicone having an HLB of 5 or more, and the HLB is more preferably 6 or more, more preferably 7 or more, and preferably 16 or less, more preferably 15.5 or less, 15 The absorbent article according to any one of <1> to <14>, wherein the following is more preferable.
<16>
Any of <1> to <15>, wherein the second sheet has a polyoxyalkylene-modified silicone, and the polyoxyalkylene-modified silicone has at least one modified group selected from polyoxyethylene modification and polyoxypropylene modification. Or an absorbent article according to claim 1.

（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以上１２以下の直鎖又は分岐鎖のアルキル鎖を表わす。Ｒ^１及びＲ^２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以上１６以下の直鎖又は分岐鎖のアルキル基を表わす。Ｘは−ＳＯ_３Ｍ、−ＯＳＯ_３Ｍ又は−ＣＯＯＭを表わし、ＭはＨ、Ｎａ、Ｋ、Ｍｇ、Ｃａ又はアンモニウムを表わす。）
＜１８＞
前記成分（Ａ）、成分（Ｂ）及び成分（Ｃ）を含有する繊維処理剤の熱融着性繊維への付着量は、該繊維処理剤を除く熱融着性繊維の全質量に対する割合として、０．１質量％以上が好ましく、０．１５質量％以上がより好ましく、０．２質量％以上がさらに好ましく、また、１．５質量％以下が好ましく、１．０質量％以下がより好ましく、０．５質量％以下がさらに好ましい、前記＜１７＞に記載の吸収性物品。 <17>
<1> in which the surface sheet is made of a nonwoven fabric using heat-fusible fibers to which a fiber treatment agent is attached, and the fiber treatment agent contains the following components (A), (B), and (C). The absorbent article according to any one of ~ <16>.
(A) polyorganosiloxane,
(B) Phosphate ester type anionic surfactant,
(C) Anionic surfactant represented by the following general formula (I), polyoxyalkylene-modified polyhydric alcohol fatty acid ester, or alkylhydroxysulfobetaine

(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 are each independently 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 representing the is _-SO 3 M, represents -OSO ₃ M or -COOM, M represents H, Na, K, Mg, Ca or ammonium.)
<18>
The amount of the fiber treatment agent containing the component (A), the component (B) and the component (C) attached to the heat-fusible fiber is a ratio to the total mass of the heat-fusible fiber excluding the fiber treatment agent. 0.1% by mass or more is preferable, 0.15% by mass or more is more preferable, 0.2% by mass or more is more preferable, 1.5% by mass or less is preferable, and 1.0% by mass or less is more preferable. The absorbent article according to <17>, further preferably 0.5% by mass or less.

<19>
The absorbent article according to <17> or <18>, wherein the component (A) contains at least one selected from the group consisting of polydimethylsiloxane, polydiethylsiloxane, and polydipropylsiloxane.
<20>
The absorbent article according to <17> or <18>, wherein the component (A) is polydimethylsiloxane.
<21>
As the component (A), the mass average molecular weight is preferably 100,000 or more, more preferably 15
Any one of the above <17> to <20> containing polyorganosiloxane which is 10,000 or more, more preferably 200,000 or more, and preferably 1,000,000 or less, more preferably 800,000 or less, and still more preferably 600,000 or less. 2. The absorbent article according to 1.
<22>
The content ratio of 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, and 20% by mass. The absorbent article according to any one of <17> to <21>, wherein the following is more preferable.

<23>
The component (B) is an alkyl phosphate ester having stearyl phosphate ester, myristyl phosphate ester, lauryl phosphate ester, and palmityl phosphate ester saturated carbon chain, oleyl phosphate ester and palmitoleyl phosphate ester Any one of the above <17> to <22>, comprising at least one selected from the group consisting of those having an unsaturated carbon chain and those having a side chain in these carbon chains. Absorbent articles.
<24>
<17> to <<, wherein the component (B) contains at least one selected from the group consisting of mono- or dialkyl phosphates having a carbon chain of 16 or more and 18 or less and a partially neutralized salt. The absorbent article according to any one of 23>.
<25>
The content ratio of the component (B) in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less. The absorbent article according to any one of <17> to <24>, wherein

<26>
The component (C) is an anionic surfactant represented by the general formula (I), and the anionic surfactant represented by the general formula (I) is such that X in the formula is —SO ₃ M, That is, the absorbent article according to any one of <17> to <25>, wherein the hydrophilic group is a sulfo group or a salt thereof, and a dialkylsulfonic acid or a salt thereof is more preferable.
<27>
The component (C) is an anionic surfactant represented by the general formula (I), and the anionic surfactant represented by the general formula (I) is such that X in the formula is -OSO ₃ M, That is, the absorbent article according to any one of <17> to <25>, wherein the hydrophilic group is a sulfate group or a salt thereof, and a dialkyl sulfate is more preferable.
<28>
The component (C) is an anionic surfactant represented by the general formula (I), and the anionic surfactant represented by the general formula (I) is such that X in the formula is —COOM, that is, hydrophilic. The absorbent article according to any one of <17> to <25>, wherein the group is a carboxy group or a salt thereof, and a dialkylcarboxylic acid is more preferable.
<29>
The component (C) is an anionic surfactant represented by the general formula (I), and the content ratio of the component (C) in the fiber treatment agent is preferably 1% by mass or more, more preferably The absorbent article according to any one of <17> to <28>, which is 5% by mass or more, preferably 20% by mass or less, more preferably 13% by mass or less.
<30>
The component (C) is an anionic surfactant represented by the general formula (I), and the content ratio of the component (A) and the component (C) in the fiber treatment agent is a mass ratio. The absorbent article according to any one of <17> to <29>, preferably from 1: 1.6 to 1: 0.6, more preferably from 1: 1.3 to 1: 0.9. .

<31>
The component (C) is the polyoxyalkylene-modified polyhydric alcohol fatty acid ester. As the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, an alkylene oxide is added to a polyhydric alcohol fatty acid ester that is an esterified product of a polyhydric alcohol and a fatty acid. The absorbent article according to any one of the above items <17> to <25>, containing a product to which is added.
<32>
The absorbent article according to <31>, wherein the polyhydric alcohol fatty acid ester is an esterified product of an alcohol having a valence of 3 or more and an alcohol component has an esterification rate of 90% or more.
<33>
The absorbent article according to <31> or <32>, wherein the alkylene oxide added to the polyhydric alcohol fatty acid ester is ethylene oxide, propylene oxide, or butylene oxide.
<34>
Any one of the above <31> to <33>, wherein the number of added moles of the alkylene oxide is preferably more than 20 moles, more preferably 40 moles or more, and preferably 80 moles or less, more preferably 60 moles or less. Absorbent article according to item.
<35>
<17> to <25>, wherein the component (C) is the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, and the polyoxyalkylene-modified polyhydric alcohol fatty acid ester contains polyoxyethylene-modified hydrogenated castor oil. The absorbent article according to any one of <31> to <34>.
<36>
The component (C) is the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, and the content of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is preferably 5% by mass with respect to the total mass of the fiber treatment agent. The above <17> to <25> and <31> to <35>, more preferably 10% by mass or more, and preferably 20% by mass or less, and more preferably 15% by mass or less. Absorbent article as described in 1.
<37>
The component (C) is the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, and the content ratio of the component (A) to the component (C) is preferably a mass ratio, preferably 1: 2 to 3: 1. The absorbent article according to any one of <17> to <25> and <31> to <36>, more preferably 1: 1 to 2: 1.

<38>
The component (C) is the alkylhydroxysulfobetaine, and the alkylhydroxysulfobetaine is at least one selected from the group consisting of laurylhydroxysulfobetaine, myristylhydroxysulfobetaine, palmitylhydroxysulfobetaine, and stearylhydroxysulfobetaine. The absorbent article according to any one of <17> to <25>, which is contained.
<39>
The component (C) is the alkylhydroxysulfobetaine, and the alkylhydroxysulfobetaine is contained in a proportion of less than 10% by mass, more preferably in a proportion of less than 9% by mass, based on the total mass of the fiber treatment agent. More preferably, it is contained in a proportion of less than 8% by mass, preferably in a proportion of 3% by mass or more, more preferably in a proportion of 5% by mass or more, in any one of the above <17> to <25> The absorbent article as described.
<40>
The component (C) is the alkylhydroxysulfobetaine, and the content ratio of the component (A) and the component (C) is 1: 1.6 to 1: 0.6 by mass ratio, more preferably. Is the absorbent article according to any one of <17> to <25>, wherein the ratio is 1: 1.3 to 1: 0.9.

<41>
The content ratio of the component (A) and the component (B) in the fiber treatment agent is a mass ratio, preferably 1: 5 to 10: 1, more preferably 1: 2 to 3: 1. The absorbent article according to any one of <17> to <40>.

<42>
The fiber treatment agent further has an alkyl phosphate having 6 to 22 carbon atoms, particularly 8 to 22 carbon atoms, an alkyl phosphate sodium salt, an alkyl ether phosphate sodium salt, a dialkyl phosphate sodium salt, a dialkyl sulfosuccinate sodium salt, and an alkylbenzene sulfonate sodium salt. And at least one anionic surfactant selected from the group consisting of alkyl sulfonate sodium salt, alkyl sulfate sodium salt and secondary alkyl sulfate sodium salt, and other alkali metal salts thereof. 41> The absorbent article according to any one of 41>.
<43>
The fiber treatment agent is further alkyl (or alkenyl) trimethylammonium halide, dialkyl (or alkenyl) dimethylammonium halide and alkyl (or alkenyl) pyridinium halide, and an alkyl group or alkenyl group having 6 to 18 carbon atoms in these compounds. Any one of the above <17> to <42>, wherein the halogen compound in the halide compound is preferably chlorine or bromine, and includes at least one cationic surfactant selected from the group consisting of The absorbent article as described.
<44>
The fiber treatment agent further contains a zwitterionic surfactant made of alkylbetaine, and the alkylbetaine is alkyl (1 to 30 carbon atoms) dimethylbetaine, alkyl (1 to 30 carbon atoms) amide alkyl ( 1 to 4 carbon atoms) dimethyl betaine, alkyl (1 to 30 carbon atoms) dihydroxyalkyl (1 to 30 carbon atoms) betaine, sulfobetaine-type amphoteric surfactant, betaine-type zwitterionic surfactant, alanine Type [alkyl (C1 or more and 30 or less) aminopropionic acid type, alkyl (C1 or more and 30 or less) iminodipropionic acid type, etc.] Amphoteric surfactant, glycine type such as alkylbetaine [alkyl (C1 or more) 30 or less) aminoacetic acid type and the like] amino acid type amphoteric surfactant such as amphoteric surfactant, alkyl 1 to 30 carbon atoms) containing at least one selected from the group consisting of amino acid type amphoteric surfactants such as taurine-type absorbent article according to any one of the <17> - <43>.
<45>
The fiber treatment agent is a polyalcohol fatty acid ester such as glycerin fatty acid ester, poly (preferably n = 2 to 10) glycerin fatty acid ester, sorbitan fatty acid ester (all preferably fatty acid having 8 to 60 carbon atoms). , Polyoxyalkylene (added mole number 2 to 60) alkyl (carbon number 8 to 22) amide, polyoxyalkylene (addition mole number 2 to 60) alkyl (carbon number 8 to 22) ether, polyoxyalkylene <17> to <44> comprising at least one nonionic surfactant selected from the group consisting of modified silicone, amino-modified silicone, polyoxyethylene alkylamide and polyoxyethylene, polyoxypropylene-modified silicone Absorbent article given in any 1

<46>
The heat-fusible fiber is an absorbent article according to any one of <17> to <45>, wherein at least a surface is formed of a polyolefin resin.
<47>
The absorbent article according to any one of <17> to <46>, wherein the heat-fusible fiber is a heat-fusible core-sheath composite fiber.
<48>
The heat-fusible fiber is an absorbent article according to any one of <17> to <47>, wherein the heat-fusible fiber is a heat-extensible composite fiber whose length is increased by heating.
<49>
The absorbent article according to any one of <17> to <48>, wherein the heat-fusible fiber contains titanium oxide.

<50>
The nonwoven fabric forming the surface sheet has irregularities composed of a plurality of convex portions projecting to the surface side and concave portions located between the convex portions,
The difference between the contact angle of water with respect to the fibers contained at the top of the convex portion and the contact angle of water with respect to the fibers contained on the back surface located on the opposite side of the surface is preferably 3 degrees or more, more preferably 5 The absorbent article according to any one of the above items <17> to <49>, which is at least 25 degrees, preferably 25 degrees or less, and more preferably 20 degrees or less.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is limited to this and is not interpreted. In the examples, “part” and “%” are based on mass unless otherwise specified.

Example 1
(1) Creation of surface sheet The surface sheet which consists of two types of fibers with which the fiber 1 and the fiber 2 were mixed by 1: 1 as follows was produced.
First, as the fiber 1, the core part was made of PET resin, the sheath part was made of PE resin, and a heat-extensible fiber having a fineness of 4.2 dtex was used and immersed in a fiber treatment agent P-1 having the following composition. The thermally extensible fiber contained 3.0% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After soaking, drying was performed to obtain a heat-extensible fiber to which the fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.

(Fiber treatment agent P-1)
Alkyl phosphate ester potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 25.0% by mass
Dioctyl sulfosuccinic acid [the above component (C), manufactured by Kao Corporation, Perex OT-P (trade name)]: 10.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the above components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 20.0% by mass
Polyoxyethylene (added mole number: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemical Co., Ltd., Amisole SDE (trade name)]: 30.0% by mass
Alkyl (stearyl) betaine [components other than the above components (A) to (C), manufactured by Kao Corporation, Anhitoal 86B (trade name)]: 15.0% by mass

  Moreover, as the fiber 2, the core part was made of PET resin, the sheath part was made of PE resin, and a heat-fusible core-sheath composite fiber having a fineness of 3.3 dtex was used and immersed in a fiber treatment agent Q-1 having the following composition. The heat-fusible core-sheath composite fiber contained 3.0% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.

(Fiber treatment agent Q-1)
Alkyl phosphate ester potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 25.0% by mass
Dioctyl sulfosuccinic acid [the above component (C), manufactured by Kao Corporation, Perex OT-P (trade name)]: 10.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the above components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 20.0% by mass
Polyoxyethylene (added mole number: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemical Co., Ltd., Amisole SDE (trade name)]: 30.0% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Anhitoal 86B]: 15.0% by mass

Subsequently, the nonwoven fabric for surface sheets was manufactured using the obtained fibers 1 and 2. A specific manufacturing method is as follows. First, the fibers 1 and 2 were mixed with 1: 1 and embossed. The embossing was performed such that a grid-like embossed part was formed and the area ratio of the embossed part (compressed part) was 22%. The embossing processing temperature was 110 ° C. Next, air-through processing was performed. In the air-through process, heat treatment was performed once by blowing hot air from the embossed surface side in the embossing process. The heat treatment temperature for air-through processing was 136 ° C.
As shown in FIGS. 2 (i) and 2 (ii), the obtained nonwoven fabric has a thin portion (embossed portion) 58 and a thick portion 59 other than that, and one side has a convex portion 69 and a concave portion. The uneven surface 51 having a large undulation having 68 and the other surface are a substantially flat surface 52.
The thickness of the obtained nonwoven fabric was 1.2 mm at the thick portion 58.

(2) Production of second sheet A second sheet was produced as follows.
First, an air-through nonwoven fabric is formed by air-through processing at 136 ° C. using a heat-fusible core-sheath composite fiber having a core part made of polyethylene terephthalate resin and a sheath part made of polyethylene resin and a fineness of 2.2 dtex, and then embossed. Processed. The embossing was performed so that a dot-like embossed part was formed and the area ratio of the embossed part was 25%. Moreover, the said fiber was immersed in the fiber processing agent R-1 of the following composition. The heat-fusible core-sheath composite fiber contained 0.15% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fiber was 0.38% by mass.

(Fiber treatment agent R-1)
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [manufactured by Shin-Etsu Chemical Co., Ltd., KF6012 (HLB7) (trade name)]: 100.0% by mass

The resulting nonwoven fabric had a thickness of 0.6 mm and a basis weight of 26.9 g / m ² .
The contact angle in the nonwoven fabric was 46 degrees as measured based on the above-described (Measurement Method of Contact Angle). In addition, the fiber used as a measurement object is cut out with a fiber length of 1 mm using precision scissors and tweezers, and is taken out from the nonwoven fabric.
Furthermore, the capillary force of the nonwoven fabric was 2.7 × 10 ³ N as measured based on the above-described (Method for measuring capillary force).

(3) Production of Absorber Absorber A composed of two types of absorbent sheets was produced as follows. Each absorbent sheet was prepared according to the method described in Japanese Patent No. 29963647 (mainly the method described in paragraphs [0079] to [0087]), and has a high water absorption between two hydrophilic fiber assemblies. The water-absorbent sheet sandwiched and fixed polymer particles. The size of one of the two water-absorbing sheets was 90 mm wide and 90 mm long, and the size of the other water-absorbing sheet was 160 mm wide and 215 mm long.
First, the absorbent body B was produced by folding a water-absorbent sheet having a width of 90 mm and a length of 90 mm into a three-fold state to have a width of 35 mm and a length of 90 mm. Further, the absorbent body A was created by folding an absorbent sheet having a width of 160 mm and a length of 215 mm so as to cover the absorbent body B into a length of 215 mm and a width of 75 mm.
The thickness of the liquid absorption part of the obtained absorbent body was 3.2 mm.
The density of the obtained absorber was 0.15 g / cm ^{3 as} measured based on the above-described (Density Measuring Method).
Moreover, the absorption rate under pressure of the obtained absorber was 14.5 seconds as measured based on the above-described (Measurement method of absorption rate).

(Example 2 to Example 6)
The nonwoven fabric for the surface sheet was produced in the same manner as in Example 1.
In the production of the nonwoven fabric for the second sheet, as the fiber treatment agent R-2, polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name) )] Comprising 100% was used. Other than that was carried out similarly to Example 1, and produced the nonwoven fabric for 2nd sheets.

In addition, the thickness of the nonwoven fabric for second sheets of Examples 2 to 6 was 0.8 mm, and the basis weight was 26.9 g / m ² . Moreover, the contact angle of the nonwoven fabric for second sheets of Example 2 to Example 6 was 52 degrees, and the capillary force was 2.0 × 10 ³ N.

The absorber of Example 2 was produced in the same manner as Example 1.
The absorber of Example 3 was made to have a thickness of 2.5 mm using the absorber A of Example 1. The reason why the thickness was thinner than in Example 1 was that the number of times the absorber B was folded was reduced to one (because it was folded in two instead of three). Moreover, the density of the absorber of Example 3 was 0.15 g / m ² , and the absorption rate under pressure was 21.5 seconds.
The absorbent body of Example 4 is made of only one absorbent sheet excluding the absorbent body B in the configuration of the absorbent body A, and the water absorbent body in the outer folded state of the absorbent body A. It consisted of only a sheet. The thickness was 1.5 mm. Moreover, the density of the absorber of Example 4 was 0.15 g / m ² , and the absorption rate under pressure was 32.4 seconds.
The absorbent body of Example 5 is an absorbent body C produced by sandwiching SAP between a spunlace nonwoven fabric having a basis weight of 35 gsm made of rayon and PP / PE and an air-through nonwoven fabric having a basis weight of 18 gsm made of PP / PE. Yes, the thickness was 1.3 mm. The density of the absorber was 0.2 g / cm ³ and the absorption rate under pressure was 38.3 seconds.
The absorber of Example 6 was an absorber C manufactured in the same manner as in Example 5, and was folded once. Its thickness was 2.5 mm. The density of the absorber was 0.21 g / cm ³ and the absorption rate under pressure was 22.8 seconds.

(Example 7)
The nonwoven fabric and the absorbent body for the top sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was produced as follows.
First, an air-through nonwoven fabric is formed by air-through processing at 136 ° C. using a heat-fusible core-sheath composite fiber having a core part made of polyethylene terephthalate resin and a sheath part made of polyethylene resin and a fineness of 2.2 dtex, and then embossed. Processed. The embossing was performed so that a dot-like embossed part was formed and the area ratio of the embossed part was 25%. Moreover, the said fiber was immersed in the fiber processing agent R-3 of the following composition. In addition, 0.15 mass% of titanium oxide was contained in the heat | fever extensible fiber with the mass ratio of the fiber. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fiber was 0.37% by mass.

(Fiber treatment agent R-3)
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [manufactured by Shin-Etsu Chemical Co., Ltd., KF6012 (HLB7) (trade name)]: 80.0 mass%
Polyoxyethylene (added mole number: 2) alkylamide [manufactured by Kawaken Fine Chemical Co., Ltd., Amizole SDE (trade name)]: 20.0% by mass

Subsequently, the nonwoven fabric for second sheets was manufactured similarly to Example 1 using the obtained fiber.
The resulting nonwoven fabric had a thickness of 0.8 mm and a basis weight of 25.2 g / m ² .
The contact angle in the nonwoven fabric was 60 degrees as measured based on the above-described (Measurement Method of Contact Angle). Furthermore, the capillary force of the nonwoven fabric was 1.5 × 10 ³ N as measured based on the above-described (Method for measuring capillary force).

(Example 8)
The nonwoven fabric and the absorbent body for the top sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 7, except that the fineness of the fiber used was 2.8 dtex, and the amount of the fiber treatment agent R-3 attached was 0.40% by mass. The resulting nonwoven fabric had a thickness of 0.7 mm and a basis weight of 24.3 g / m ² . The contact angle was 56 degrees. Furthermore, the capillary force was 1.7 × 10 ³ N.

Example 9
The nonwoven fabric and the absorbent body for the top sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 7 except that the fineness of the fiber used was 3.3 dtex and the amount of the fiber treatment agent R-3 attached was 0.40% by mass. The resulting nonwoven fabric had a thickness of 0.7 mm and a basis weight of 24.5 g / m ² . The contact angle was 54 degrees. Furthermore, the capillary force was 1.9 × 10 ³ N.

(Example 10)
The nonwoven fabric and the absorbent body for the top sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 1 except that the fineness of the fibers used was 2.2 dtex and the content of titanium oxide was 3.0% by mass. The resulting nonwoven fabric had a thickness of 0.6 mm and a basis weight of 24.8 g / m ² . The contact angle was 55 degrees. Furthermore, the capillary force was 2.0 × 10 ³ N.

(Example 11)
The absorber was obtained in the same manner as in Example 1. The nonwoven fabric for the second sheet was obtained in the same manner as in Example 10.
The nonwoven fabric for the surface sheet 1 was obtained as follows.
A surface material composed of two types of fibers in which the fibers 1 and 2 were mixed at a ratio of 1: 1 was prepared. First, as the fiber 1, the core part was made of PET resin, the sheath part was made of PE resin, and a heat-extensible fiber having a fineness of 4.2 dtex was used and immersed in a fiber treatment agent P-2 having the following composition. The thermally extensible fiber contained 3.0% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After soaking, drying was performed to obtain a heat-extensible fiber to which the fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.

(Fiber treatment agent P-2)
Alkyl phosphate ester potassium salt [the above component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 22.5% by mass
Polydimethylsiloxane [said component (A), silicone “KM903” manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Dioctylsulfosuccinic acid [the above component (C), manufactured by Kao Corporation, Perex OT-P (trade name)]: 9.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 18.0% by mass
Polyoxyethylene (number of added moles: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 27.0% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 13.5% by mass

  Moreover, as the fiber 2, the core part was made of PET resin, the sheath part was made of PE resin, and a heat-fusible core-sheath composite fiber having a fineness of 3.3 was used and immersed in a fiber treatment agent Q-2 having the following composition. The heat-fusible core-sheath composite fiber contained 3.0% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.

(Fiber treatment agent Q-2)
Alkyl phosphate ester potassium salt [the above component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 22.5% by mass
Polydimethylsiloxane [the component (A), silicone “KM903” (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Dioctylsulfosuccinic acid [the above component (C), manufactured by Kao Corporation, Perex OT-P (trade name)]: 9.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 18.0% by mass
Polyoxyethylene (number of added moles: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 27.0% by mass
Alkyl (stearyl) betaine [components other than the above components (A) to (C), manufactured by Kao Corporation, Anhitoal 86B (trade name)]: 13.5% by mass

  In addition, the compounding quantity of a component (A) is a compounding quantity of only silicone among the composition of said "KM-903", and is not the compounding quantity of "KM-903" whole. That is, the blending ratio of each component of the fiber treatment agent shown in Table 2 is a value calculated by excluding the dispersant and water in KM-903.

  Subsequently, using the obtained fibers 1 and 2, a nonwoven fabric for a surface sheet was produced in the same manner as in Example 1.

(Example 12 to Example 15)
The absorber was obtained in the same manner as in Example 1. Moreover, the nonwoven fabric for second sheets was obtained in the same manner as in Example 10.
The nonwoven fabric for the surface sheet was obtained as follows.
A surface material composed of two types of fibers in which the fibers 1 and 2 were mixed at a ratio of 1: 1 was prepared. First, as the fiber 1, the core part is made of PET resin, the sheath part is made of PE resin, and a heat-fusible core-sheath composite fiber having a fineness of 3.3 dtex is used and immersed in the same fiber treatment agent P-1 as in Example 1. . The heat-fusible core-sheath composite fiber contained 3.0% by mass of titanium oxide in the mass ratio of the fiber. The titanium oxide was contained in the core part of the core-sheath structure. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.
As fiber 2, it was immersed in the same fiber treating agent Q-1 as Example 1, and the heat-fusible core-sheath composite fiber was obtained. The adhesion amount of the fiber treatment agent to the fibers was 0.4% by mass.
Subsequently, using the obtained fibers 1 and 2, a nonwoven fabric for a surface sheet was produced in the same manner as in Example 1 except that embossing was not performed. The obtained nonwoven fabrics of Example 12 to Example 15 were not uneven and both surfaces were flat.
The thickness of the nonwoven fabric of Example 12 is 1.2 mm, the thickness of the nonwoven fabric of Example 13 is 2.0 mm, the thickness of the nonwoven fabric of Example 14 is 1.6 mm, and the thickness of the nonwoven fabric of Example 15 is It was 0.8 mm. Each of the nonwoven fabrics of Examples 12 to 15 was sampled and crushed by pressurizing at 10 kPa for 24 hours, and then put into an electric dryer at 100 ° C. to restore the thickness to the desired thickness. Obtained.

(Example 16)
The nonwoven fabric and the absorbent body for the surface sheet were obtained in the same manner as in Example 1.
The non-woven fabric for the second sheet is dioctylsulfosuccinic acid [manufactured by Kao Corporation, PELEX OT-P (trade name)] 100 mass% as the fiber treatment agent R-4, and the amount of the fiber treatment agent attached to the fiber Was obtained in the same manner as in Example 1 except that the content was changed to 0.4% by mass. The obtained nonwoven fabric had a thickness of 0.6 mm and a basis weight of 25.4 g / m ² . The contact angle was 32 degrees. The capillary force was 3.1 × 10 ³ N.

(Example 17)
The nonwoven fabric for the top sheet was obtained in the same manner as in Example 1. The absorber was obtained in the same manner as in Example 1 except that in the absorber A, the water absorbent sheet used as the absorber B was folded in four. However, the thickness of the absorber was 4.0 mm, the density was 0.15 g / cm ³ , and the absorption rate under pressure was 12.1 seconds.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 2. The resulting nonwoven fabric had a thickness of 0.8 mm and a basis weight of 26.9 g / m ² . The contact angle was 52 degrees. The capillary force was 2.0 × 10 ³ N.

(Example 18)
A nonwoven fabric and an absorbent body for the second sheet were obtained in the same manner as in Example 10.
The non-woven fabric for the topsheet has a fiber treatment agent P-3 having the following composition with respect to the fiber 1 and an amount of adhesion to the fiber of 0.43% by mass, and a fiber treatment agent Q- having the following composition with respect to the fiber 2. 3 was used in the same manner as in Example 10 except that the amount of adhesion to the fiber was 0.43% by mass.

(Fiber treatment agent P-3)
Alkyl phosphate potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 22.2% by mass
Polydimethylsiloxane [said component (A), silicone “KM903” manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Polyoxyethylene (POE) (added mole number 40) modified polyhydric alcohol fatty acid ester [the component (C), manufactured by Kao Corporation, Emanon CH40]: 10.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the above components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 17.8% by mass
Polyoxyethylene (number of moles added: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 26.7% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 13.3% by mass

(Fiber treatment agent Q-3)
Alkyl phosphate potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 22.2% by mass
Polydimethylsiloxane [said component (A), silicone “KM903” manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Polyoxyethylene (POE) (added mole number 40) modified polyhydric alcohol fatty acid ester [the component (C), manufactured by Kao Corporation, Emanon CH40]: 10.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the above components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 17.8% by mass
Polyoxyethylene (number of moles added: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 26.7% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 13.3% by mass

(Example 19)
A nonwoven fabric and an absorbent body for the second sheet were obtained in the same manner as in Example 10.
The nonwoven fabric for the topsheet is a fiber treatment agent P-4 having the following composition with respect to the fiber 1 and the amount of adhesion to the fiber is 0.42% by mass. 4 was used in the same manner as in Example 10 except that the amount of adhesion to the fiber was 0.42% by mass.

(Fiber treatment agent P-4)
Alkyl phosphate potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 23.6% by mass
Polydimethylsiloxane [said component (A), silicone “KM903” manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Alkylhydroxysulfobetaine [the above component (C), manufactured by Kao Corporation, Amphital 20HD]: 5.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 18.9% by mass
Polyoxyethylene (number of moles added: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 28.3% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 14.2% by mass

(Fiber treatment agent Q-4)
Alkyl phosphate potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 23.6% by mass
Polydimethylsiloxane [said component (A), silicone “KM903” manufactured by Shin-Etsu Chemical Co., Ltd.]: 10.0% by mass
Alkylhydroxysulfobetaine [the above component (C), manufactured by Kao Corporation, Amphital 20HD]: 5.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [components other than the components (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515 (HLB5) (trade name)]: 18.9% by mass
Polyoxyethylene (number of moles added: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemicals Co., Ltd., Amizole SDE (trade name)]: 28.3% by mass
Alkyl (stearyl) betaine [components other than the above-mentioned components (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 14.2% by mass

(Comparative Example 1)
The nonwoven fabric and the absorbent body for the surface sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 1 except that the following fiber treatment agent R-5 was used and the amount of the fiber treatment agent attached to the fibers was 0.4% by mass. The obtained nonwoven fabric had a thickness of 0.7 mm and a basis weight of 26.7 g / m ² . The contact angle was 73 degrees. The capillary force was 1.0 × 10 ³ N.

(Fiber treatment agent R-5)
Alkyl phosphate potassium salt (Kao Corporation, neutralized potassium hydroxide of gripper 4131): 30.0% by mass
Dioctyl sulfosuccinic acid [manufactured by Kao Corporation, PELEX OT-P (trade name)]: 15.0% by mass
Polyoxyethylene (POE) polyoxypropylene (POP) modified silicone [manufactured by Shin-Etsu Chemical Co., Ltd., KF6012 (HLB7)]: 10.0% by mass
Polyoxyethylene (added mole number: 2) alkylamide [components other than the above components (A) to (C), manufactured by Kawaken Fine Chemical Co., Ltd., Amisole SDE (trade name)]: 30.0% by mass
Alkyl (stearyl) betaine [Kao Co., Ltd., Amphitol 86B]: 15.0% by mass

(Comparative Example 2 to Comparative Example 8)
The nonwoven fabric for the top sheet and the nonwoven fabric for the second sheet were obtained in the same manner as in Comparative Example 1.

The absorber of Comparative Example 2 was obtained in the same manner as Example 3. The obtained absorber had a thickness of 2.5 mm and a density of 0.15 g / cm ³ . The absorption rate under pressure was 21.5 seconds.
The absorber of Comparative Example 3 was obtained in the same manner as Example 4. The obtained absorber had a thickness of 1.5 mm and a density of 0.15 g / cm ³ . The absorption rate under pressure was 32.4 seconds.
The absorber of Comparative Example 4 was obtained in the same manner as Example 5. The obtained absorber had a thickness of 1.5 mm and a density of 0.20 g / cm ³ . The absorption rate under pressure was 38.3 seconds.
The absorbent body of Comparative Example 5 was obtained in the same manner as in Example 6. The obtained absorber had a thickness of 2.5 mm and a density of 0.21 g / cm ³ . The absorption rate under pressure was 22.8 seconds.

The absorbent bodies of Comparative Examples 6 to 8 are those in which an aggregate of pulp fibers is wrapped with a covering sheet made of cellulose fibers (this is referred to as a pulp absorbent body).
The thickness of the absorbent body of Comparative Example 6 was 4.6 mm, the density was 0.06 g / cm ³ , and the absorption rate under pressure was 6.4 seconds.
The thickness of the absorbent body of Comparative Example 7 was 3.5 mm, the density was 0.08 g / cm ³ , and the absorption rate under pressure was 10.4 seconds.
The thickness of the absorber of Comparative Example 8 was 2.3 mm, the density was 0.12 g / cm ³ , and the absorption rate under pressure was 11.9 seconds.

(Comparative Example 9)
The nonwoven fabric and the absorbent body for the surface sheet were obtained in the same manner as in Example 1.
The nonwoven fabric for the second sheet was obtained in the same manner as in Example 1 except that the following fiber treatment agent R-6 was used and the amount of the fiber treatment agent attached to the fibers was 0.42% by mass. The obtained nonwoven fabric had a thickness of 0.7 mm and a basis weight of 25.3 g / m ² . The contact angle was 67 degrees. The capillary force was 1.3 × 10 ³ N.

(Fiber treatment agent R-6)
Alkyl phosphate ester potassium salt [manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131 (trade name)]: 40.0% by mass
Dioctylsulfosuccinic acid [manufactured by Kao Corporation, Perex OT-P (trade name)]: 30.0% by mass
Alkyl (stearyl) betaine [manufactured by Kao Corporation, Anhitoal 86B (trade name)]: 30.0% by mass

(Comparative Example 10 to Comparative Example 12)
The nonwoven fabric for the top sheet and the nonwoven fabric for the second sheet were obtained in the same manner as in Example 2.
The absorber was obtained in the same manner as in Comparative Example 6.
The thickness of the absorbent body of Comparative Example 10 was 4.6 mm, the density was 0.06 g / cm ³ , and the absorption rate under pressure was 6.4 seconds.
The thickness of the absorbent body of Comparative Example 11 was 3.5 mm, the density was 0.08 g / cm ³ , and the absorption rate under pressure was 10.4 seconds.
The thickness of the absorber of Comparative Example 12 was 2.3 mm, the density was 0.12 g / cm ³ , and the absorption rate under pressure was 11.9 seconds.

(Concealment rate: red plate concealment rate)
The red plate concealment ratio was measured as follows by placing the attached standard plate (red) on the nonwoven fabric for second sheets obtained in Examples 1 to 17 and Comparative Examples 1 to 12.
First, the attached standard plate (with the red surface as the measurement surface) was measured using a simple spectral color difference meter NF333 manufactured by Nippon Denshoku Industries Co., Ltd. Among the obtained absorption wavelengths, 500 cm −1 was particularly selected, and the reflectance at this time was recorded (Ra). Next, remove the red plate, place the sample on the sample stage, and further so that the back surface of the sample (the surface opposite to the measurement surface, the second surface 10B (surface with the second layer 2) and the red surface of the red plate face each other. A red plate was placed, and the measurement was performed five times at different sites for one sample, and the average value (Rb) of the reflectance of 500 cm −1 was calculated. Was determined by the following equation (1).
Red plate concealment rate (%)
= [(Rb-Ra) / (100-Ra)] x 100 (1)
The higher the value obtained as a result of the above measurement, the higher the concealability of the nonwoven fabric, and the higher the whiteness (L value) after liquid absorption, and the surface material of the non-liquid absorption part. In addition, the redness of the absorber of the liquid absorbing portion is concealed, leading to an improvement in the whiteness (L value) of the blood of the absorber over the surface material.

(Evaluation)
First, a sanitary napkin for evaluation was prepared as follows. As an example of the absorbent article, members from the top sheet to the absorbent body were removed from a sanitary napkin (manufactured by Kao Corporation: Laurie Speed + Skin Clean Guard, manufactured in 2013). There, the absorbent body of each example and each comparative example is placed, the non-woven fabric for the second sheet is cut into a predetermined size and laminated, and the non-woven fabric for the top sheet is further cut into a predetermined size. Laminated and fixed around it. This was used as a sanitary napkin for evaluation of each example and each comparative example.

(Liquid remaining amount)
An acrylic plate having a transmission hole with an inner diameter of 1 cm is overlaid on the surface of each evaluation sanitary napkin, and a constant load of 100 Pa is applied to the napkin. Under such a load, 3.0 g of defibrinated horse blood (a product obtained by adjusting equine defibrinated blood manufactured by Japan Biotest Laboratories to 8.0 cP) is poured from the perforation hole of the acrylic plate. Adjustment was performed under the condition of 30 rpm with a Toki Sangyo TVB10 viscometer. When the horse blood is allowed to stand, a high-viscosity part (such as red blood cells) precipitates, and a low-viscosity part (plasma) remains as a supernatant. The mixing ratio of the part was adjusted to 8.0 cP. 120 seconds after the defibrinated horse blood is poured, 3.0 g of defibrinated horse blood is further poured. Acrylic board is removed 30 minutes after injecting a total of 6.0 g of defibrinated horse blood. Subsequently, the mass (W2) of the nonwoven fabric test body of the surface sheet is measured, and the difference (W2−W1) from the previously measured mass (W1) of the nonwoven fabric test body before pouring horse blood is calculated. The above operation is performed three times, and the average value of the three times is defined as the remaining liquid amount (mg). The liquid remaining amount is an index of how much the wearer's skin gets wet. The smaller the liquid remaining amount, the better the result.

(Measurement of concealment)
About the sanitary napkin for each evaluation, L value of the surface sheet (nonwoven fabric test body) surface was measured. Specifically, the L value at the position where defibrinated horse blood was introduced was measured using a simple spectral color difference meter NF333 manufactured by Nippon Denshoku Industries Co., Ltd. One was to measure the L value (lightness) of the portion where the redness of the topsheet and the redness of the absorber overlapped. The other was to measure the L value of the portion of the surface sheet where there was no redness and the portion of the absorber where the redness was present, using the spectral color difference meter. In Tables 1 to 3, the former value is shown in the “whiteness after 30 minutes” column, and the latter value is shown in the “blood whiteness of the absorbent body as seen over the surface material” column. That is, “whiteness after 30 minutes” indicates the redness hiding property of both the surface sheet itself and the absorber, and “the whiteness of the blood of the absorber seen through the surface material” indicates the redness hiding property of the absorber. Show.
L value (lightness) indicates that the larger the value, the closer the color is to white, and the less redness is visible on the top sheet (nonwoven fabric test body). That is, the concealment property is high. If the “whiteness after 30 minutes” is 62 or more and the “whiteness of the blood of the absorbent body seen through the surface material” is 70 or more, it is determined that the nonwoven fabric has high performance as a concealing property.
The L value was measured when 30 g had passed after 3.0 g of defibrinated horse blood was poured in through 3.0 g from the perforation hole of the acrylic plate.

(Absorptive sensory evaluation)
Similar to the evaluation of the remaining liquid, after putting 6.0 g of defibrinated horse blood, put the sample after 30 minutes on a flat table, and just determine the appearance after absorption according to the following three criteria. did. The results were obtained with 10 monitors (adult women in their 20s to 40s) as subjects, and the results were shown as an average.
Judgment criteria 3: It looks white and feels good absorbency.
2: Appears red and slightly absorbs.
1: Appearance is reddish and absorbability is poor.

(Evaluation of wearing feeling)
Two sanitary napkins for each evaluation were distributed for each type of napkin, and 5 panels (adult women in their 20s to 40s) were allowed to wear them for 2 hours or more per sheet. The wearing feeling in the part was subjected to sensory evaluation based on the following criteria.
Evaluation of wearing feeling A: 80% or more panels do not feel uncomfortable (4 or more / 5 people)
B: 40-60% or more panels do not feel uncomfortable (2-3 people / 5 people)
C: Less than 40% of panels that do not feel strange (less than 2 people / 20 people)

  The composition of the above Examples and Comparative Examples, and the results of each evaluation for the Examples and Comparative Examples are shown in Tables 1 to 3 below.

As shown in Table 1-3, Examples 1 to 17, a density 0.12 g / ^{m 3} greater than the absorber, the capillary force 1.5 × 10 ³ N or more conditions of the second sheet filled, capillary forces the defining The liquid residue was suppressed less than Comparative Examples 1 to 5 and 9 below the value, and the L values of the two types of “whiteness” were high, and the whiteness could be experienced as the user's time. This is considered that the capillary force of the second sheet is sufficiently exerted on the absorbent body having a specified density, the liquid remaining is small, and the L value representing whiteness is high.
Moreover, all Examples 1-16, 18, and 19 were evaluated that the wearing feeling was “A” and “80% or more of the panels did not feel strange”. That is, it can be said that due to the thinning, the wearing feeling is so excellent that it is not conscious that it has been attached without feeling a foreign object. On the other hand, Comparative Examples 6-8 and 10-12 were evaluated as "B" or "C", and did not reach the wearing feeling like an Example. This seems to be due to the difference in thickness depending on the density of the absorber.
As described above, as shown in the above examples, it can be understood that the present invention achieves both the thinness of the absorber and the excellent absorbing power at a high level.

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorber 4 Second sheet 10 Sanitary napkin

Claims (10)

Absorbent article comprising a top sheet, a back sheet, and a liquid-retaining absorbent disposed between the top sheet and the back sheet, and a second sheet disposed between the top sheet and the absorbent Because
An absorbent article, wherein the absorbent body has a density higher than 0.12 g / cm ³ , and the second sheet has a capillary force of 1.5 × 10 ³ N or more.   2. The absorbent article according to claim 1, wherein the absorbent body has a thickness of a liquid absorbing portion at a width center of the absorbent article of 3.2 mm or less.   The absorptive article according to claim 1 or 2 whose absorption speed of said absorber is 14.5 seconds or more.   The absorbent article according to any one of claims 1 to 3, wherein the second sheet is disposed in contact with the absorber.   The fiber contained in the said 2nd sheet | seat has a fiber treatment agent, and contains polyoxyalkylene modified silicone exceeding 10 mass% with respect to the total mass of the said fiber treatment agent. The absorbent article of any one of Claims.   The absorbent article of any one of Claims 1-5 in which the fiber contained in the said 2nd sheet contains titanium oxide exceeding 0.15 mass% with the mass ratio of this fiber. The absorbent article according to claim 1 capillary force is not more than 1.5 × 10 ³ N or 3.0 × 10 ³ N of the second sheet.   The absorbent article according to any one of claims 1 to 7, wherein the second sheet has a polyoxyalkylene-modified silicone having an HLB of 5 or more.   The said 2nd sheet | seat has polyoxyalkylene modified silicone, This polyoxyalkylene modified silicone has at least 1 modified group chosen from polyoxyethylene modification and polyoxypropylene modification, The any one of Claims 1-8. Absorbent article as described in 1. The said surface sheet is a nonwoven fabric using the heat-fusible fiber which the fiber processing agent adhered, The said fiber processing agent contains the following component (A), (B) and (C). 10. The absorbent article according to any one of 9 above.
(A) polyorganosiloxane,
(B) Phosphate ester type anionic surfactant,
(C) Anionic surfactant represented by the following general formula (I), polyoxyalkylene-modified polyhydric alcohol fatty acid ester, or alkylhydroxysulfobetaine

(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 are each independently 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 representing the is _-SO 3 M, represents -OSO ₃ M or -COOM, M represents H, Na, K, Mg, Ca or ammonium.)

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