JP2019063229A - Sanitary napkin - Google Patents

Abstract

To prevent a skin trouble as much as possible by making a friction coefficient of an embossment imparting area be not more than a friction coefficient of an embossment non-imparting area in both of a standing position (0.49 kPa) and a seating position (1.6 kPa), while using a liquid-permeable surface sheet subjected to embossing.SOLUTION: A non-woven fabric is used as a liquid-permeable surface sheet 3, and a surface embossment is formed by any pattern in the use-surface side. The liquid-permeable surface sheet 3 uses a fiber with a fiber diameter of 1.9 dt or more and 3.0 dt or less. In a sliding friction test method, when a friction coefficient is measured with respect to am embossment imparting area including a portion where the surface embossment is formed and an embossment non-imparting area where the surface embossment is not imparted, the friction coefficient of the embossment imparting area is not more than the friction coefficient of the embossment non-imparting area, in both cases of a pressure loading state of 0.49 kPa assuming a standing position and the pressure loading state of 1.6 kPa assuming a seating position.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a sanitary napkin that absorbs and holds menstrual blood and prevents leakage to the back side, and in particular, a nonwoven fabric is used for the liquid-permeable surface sheet, and surface embossing is formed on the liquid-permeable surface sheet. Related to a sanitary napkin.

  Conventionally, an absorbent body made of cotton-like pulp or the like is interposed between a liquid-impervious back sheet made of polyethylene sheet or polyethylene-laminated non-woven fabric as a sanitary napkin and a liquid-permeable surface sheet made of non-woven fabric. It has been known.

  An important function required of the liquid-permeable surface sheet is to absorb body fluid quickly so that the body fluid does not come in contact with the skin for a long time, to be absorbed by the absorber, and to prevent reversion of the body fluid once absorbed. In other words, it is responsible for the liquid permeability and the liquid return and liquid residual suppression function. In addition, since it is a part that touches the skin directly, it is required that the skin be less irritating and that the touch be good.

  The interior of the sanitary napkin is humid when used, but when the body fluid is discharged, it is thought that if the body fluid is not removed from the surface of the skin, it may lead to the user's discomfort such as stuffiness and stickiness. Moreover, the thickness of the horny layer is as thin as about 1/3 to 1/2 as compared with the trunk and limbs of the vulva that the sanitary napkin contacts. Since the horny layer has a role of protecting the skin from external bacteria and irritation, it can be said that the vulva has a relatively low barrier function of the skin. As a means to solve these problems, the former problem is effective in reducing the humidity near the skin by increasing the liquid permeability of the non-woven fabric, and the latter problem is effective in reducing the friction between the permeable top sheet and the skin It becomes.

  On the other hand, the liquid-pervious surface sheet may be embossed from the surface side for the purpose of control of the diffusion region of body fluid and reduction of the surface residue of menstrual blood and food. For example, in the following Patent Document 1, in the absorbent article having a liquid-permeable surface material layer, a liquid-impermeable back surface material layer, and an absorber disposed between the two material layers, the absorber is A width dimension is narrower than the surface material layer and the back surface material layer, and a side edge extending in a longitudinal direction of the absorber is positioned inside a side edge of the surface material layer and the back surface material layer, When the region where the absorber is provided is a central region, and the side edge between the absorber and the side edges of the surface material layer and the back surface material layer is a side region, both sides of the central region are provided. In the part, an embossed compression part obtained by compressing only the surface material layer is formed continuously in the longitudinal direction or arranged in the longitudinal direction, and the embossed compression part is formed of each of the absorbers. From the central region across the side edge of the Absorbent articles are formed with a width dimension over part regions is disclosed.

  Further, in Patent Document 2 described below, in the absorbent article in which an absorbent is interposed between the liquid-permeable surface sheet and the back surface sheet, the liquid-permeable surface sheet is made of non-woven fabric, and the liquid-permeable surface sheet and The liquid-permeable top sheet is extended outward from the edge of the back sheet at least at the front and back ends of the absorbent article among the outer peripheral flaps in which the back sheet is extended outward from the edge of the absorber. A plurality of squeezing grooves arranged along the substantially longitudinal direction of the absorbent article and spaced in the width direction of the absorbent article in plan view The squeezing groove is provided with a first wave-like pattern alternately repeating a protrusion to one side and a protrusion to the other side in the width direction of the absorbent article, and the first wave-like pattern can be absorbed. Second wave reversed in the width direction of the article The pattern is formed in a wave pattern in which the pattern is alternately arranged in the width direction of the absorbent article, and the wave pattern of the squeezing groove is formed for one or more cycles at least at the front and rear ends of the absorbent article at the outer extension. An absorbent article is disclosed.

Patent No. 4278963 Patent No. 5972584 gazette

  As described above, for the control of the diffusion region of body fluid and the reduction of the surface residue of menstrual blood and food, the effect is recognized by the embossing applied to the liquid-permeable surface sheet. As clarified in the previous experiment>, when embossing is applied to the non-woven fabric, the coefficient of friction is reduced more than the non-embossed non-woven fabric in the low contact pressure state (0.49 kPa) as in the standing position. Although it can be achieved, the coefficient of friction increases in non-embossed non-woven fabrics due to the increase in the “true contact area” based on the friction adhesion theory described later under high contact pressure conditions (1.6 kPa) such as when seated. It turns out that fear is high.

  The specimen used in the above <pre-experiment> is a non-woven fabric of any specific physical property, but as described above, the vulva to which the sanitary napkin contacts is 1/3 to the thickness of the keratin compared to the trunk and limbs Since it is thin at about 1/2, the increase in the coefficient of friction should be avoided as much as possible, considering the influence on the skin.

  Therefore, the main object of the present invention is that the coefficient of friction of the embossed region is not embossed in both the standing position (0.49 kPa) and the sitting position (1.6 kPa) while using the embossed liquid-pervious surface sheet. By making the coefficient of friction of the application area or less, it is possible to avoid skin troubles as much as possible.

According to a first aspect of the present invention, there is provided a sanitary napkin in which an absorbent is interposed between a liquid-permeable top sheet and a back sheet.
A non-woven fabric is used as the liquid-pervious surface sheet, and a surface emboss is formed on the non-woven fabric at least on the use side in an arbitrary pattern,
In the liquid-permeable surface sheet, fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used as constituent fibers of the non-woven fabric of the surface layer in contact with the skin,
The coefficient of friction of the liquid-pervious surface sheet was measured using a predetermined sliding friction test method with respect to the embossed region including the portion on which the surface emboss was formed and the non-embossed region not having the surface embossed. When
The measured value under a vertical pressure load condition of 0.49 kPa, assuming a standing position, is such that the coefficient of friction of the embossed region is less than or equal to the coefficient of friction of the unembossed region,
A sanitary napkin is provided, wherein the coefficient of friction of the embossed region is equal to or less than the coefficient of friction of the non-embossed region, as measured under a vertical pressure load condition of 1.6 kPa, assuming seating. .

  In the invention according to the first aspect, a liquid-permeable surface sheet is used which is formed of a non-woven fabric having a surface emboss formed in an arbitrary pattern at least on the use surface side. In the liquid-permeable surface sheet, a fiber having a fiber diameter of 1.9 dt or more and 3.0 dt or less is used as a constituent fiber of the non-woven fabric of the surface layer in contact with the skin. As shown in the test, the coefficient of friction of the embossed region can be made equal to or less than the coefficient of friction of the unembossed region in both standing (0.49 kPa) and sitting (1.6 kPa).

  With regard to the fiber diameter, the coefficient of friction of the embossed region is equal to or less than the coefficient of friction of the non-embossed region both at standing (0.49 kPa) and sitting (1.6 kPa) with the lower limit "1.9 dt or more" as the boundary value. Can be In addition, with the upper limit value “3.0 dt or less”, if the fiber diameter is increased too much, the voids between the fibers will increase and the liquid permeability will improve, but problems such as reversion tend to occur, so this type of sanitary napkin As the surface sheet 3 of this, it was set as the numerical value of the upper limit side which can generally be taken.

  Generally, when discussing the friction of materials, there are various models such as the unevenness theory of the friction model, the adhesion theory, the digging theory, and the junction-growth model, but in the present invention, with regard to the increasing or decreasing tendency of the friction coefficient, Apply to the model of arrival theory and think.

  As will be described in detail later, according to the cohesion theory, in the case of the embossed surface material, the side portions of the embossing first have a relatively dense structure because the surrounding fibers enter during embossing. There is. Under low load such as standing (0.49 kPa), the embossed side does not deform significantly under load, and the bottom of the emboss is kept out of contact with the skin. The coefficient of friction is reduced at times (0.49 kPa) than the surface of the non-embossed nonwoven.

  On the other hand, when the load is high (1.6 kPa) such as when sitting down, the embossed side portion can not bear the load, and the embossed bottom portion comes in contact with the skin, and the embossed side portion is densely present Therefore, it was considered that the contact area increased and the true contact area tended to increase.

  Therefore, according to the present invention, as a result of intensive research into which non-woven fabric structure does not increase the contact area with the skin at the time of sitting (1.6 kPa), the cushioning property of the non-woven fabric, compression followability and compressive force are received. As a result of finding that it is effective to improve physical property characteristics such as deformation resistance at the time of bending, it came to focus on the fiber diameter of the non-woven fabric.

  In the present invention, in particular, fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used as constituent fibers of the non-woven fabric, and cushion properties of the non-woven fabric, compression followability, and deformation resistance when subjected to compressive force are improved. I made it. As a result, even under high load (1.6 kPa) such as sitting, the embossed side portion is not significantly deformed even when a load is applied, and the bottom portion of the emboss is kept in a non-contact state with the skin, Even when seated (1.6 kPa), the coefficient of friction of the embossed region can be made equal to or less than the coefficient of friction of the unembossed region.

Next, as the present invention according to claim 2, the sanitary napkin according to claim 1, wherein the sliding friction test method is a friction test carried out in accordance with the following procedures (1) to (6).
(1) A friction test is performed using a direct acting sliding friction test apparatus (Trinity Lab Co., Ltd. Speed fluctuation friction testing machine Type: μv-1000).
(2) Using an artificial skin piece made of polyurethane simulating human skin, attach the artificial skin piece to the lower part of the load cell, fix the non-woven fabric sample on the stage, and bring the artificial skin piece into contact.
(3) The weight is applied to the upper part of the load cell by the weight so that the vertical load is equivalent to the apparent contact pressure (0.49 kPa in standing position, 1.6 kPa in sitting position) applied to the attached napkin when standing and sitting. The sliding friction test is performed by loading and reciprocating the stage.
(4) The test is conducted in the air without lubrication under a sliding speed of 1 mm / s, a sliding distance of 5 mm, and a friction cycle of 10 times.
(5) The sliding direction is the machine direction which is the flow direction of the fibers of the nonwoven fabric, and the test is repeated three times under the same conditions to obtain reproducibility.
(6) The average value of the coefficient of friction in a period corresponding to 10 to 90% of the slip time at the 10th repetition is used as the coefficient of friction.

  The invention according to the second aspect specifically lists the test procedure of the sliding friction test method.

  According to a third aspect of the present invention, the liquid-pervious surface sheet is a non-woven fabric having a two-layer structure comprising an upper layer and a lower layer, and the upper layer is a high molecular weight polymer having a fiber diameter of 1.9 dt to 3.0 dt. The sanitary napkin according to any one of claims 1 and 2, wherein the lower layer comprises a high molecular weight polymer and a crimped fiber having a fiber diameter of 4.0 dt or more and 7.0 dt or less. .

  In the invention according to the third aspect, preferred examples of the liquid-permeable top sheet are specifically shown. The liquid-pervious surface sheet is a non-woven fabric having a two-layer structure comprising an upper layer and a lower layer, and the upper layer is made of a polymer polymer and fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used. It is preferable to use a polymer as a base material and a crimped fiber having a fiber diameter of 4.0 dt or more and 7.0 dt or less. Although the fiber diameter of the upper layer has been described in claim 1, by using a crimped fiber having a fiber diameter of 4.0 dt or more and 7.0 dt or less using a high molecular weight polymer as a lower layer, the crimped fiber layer It is possible to elastically support vertical pressure, and it is possible to improve the cushioning property in the thickness direction with respect to the non-woven fabric, compression followability, deformation resistance when subjected to compression force, and the like.

  According to a fourth aspect of the present invention, the liquid-pervious surface sheet is a non-woven fabric having a two-layer structure comprising an upper layer and a lower layer, and the upper layer is a polyethylene terephthalate core with a 1.9 sheath fiber diameter of polyethylene. The lower layer is a crimped fiber composed of polyethylene terephthalate as a core and a sheath of polyethylene and the thickness of the fiber is 4.0 dt or more and 7.0 dt or less, and the upper layer is a total of 40 The sanitary napkin according to any one of claims 1 and 2, wherein a non-woven fabric having a weight ratio of% or less is used.

  In the invention according to the fourth aspect, preferred examples of the liquid-permeable top sheet are shown more specifically. In the upper layer, in particular, core-sheath fibers having polyethylene terephthalate as a core material are used. Polyethylene terephthalate is relatively higher in shape stability than polyolefin fibers, and can improve cushioning properties, compression followability, and resistance to deformation when subjected to a compressive force.

  According to a fifth aspect of the present invention, there is provided the sanitary napkin according to any one of the first to fourth aspects, wherein the depth of the surface embossing is 400 μm or more and 700 μm or less.

  In the invention according to the fifth aspect, the general numerical range of the depth of the surface emboss formed on the liquid-permeable surface sheet is defined.

  The present invention according to claim 6 provides the sanitary napkin according to any one of claims 1 to 5, wherein the surface embossment is formed in a region including at least a body fluid discharge site.

  The invention according to claim 6 defines the formation area of the surface embossing. By forming a surface embossment in at least the area including the body fluid discharge site, it is possible to rapidly and longitudinally diffuse the body fluid discharged to the body fluid discharge site in the area including the body fluid discharge site, and the vulva The skin trouble can be alleviated as much as possible by applying an embossed area, which is thinner than the trunk and limbs and intended to reduce friction, to the vulva.

  In addition, in this invention, it does not exclude forming over the whole of a liquid-permeable surface sheet as a formation area of surface embossing. In this case, in the measurement of the coefficient of friction of the non-embossed area where the surface embossing is not applied, the coefficient of friction may be measured with the area where the embossing is not formed between the embossing as the measurement target. When the area to be measured is narrow, it can be dealt with by reducing the area of the artificial skin piece of the sliding friction test device or reducing the sliding distance. The present invention is an embossed area including a portion on which surface embossing is formed in a vertical pressure load condition of 0.49 kPa assuming standing and a vertical pressure load condition of 1.6 kPa assuming sitting. Since the magnitude relationship of the coefficient of friction with the non-emboss applied area not having been applied is defined, there is no problem even if the measurement conditions are optionally slightly changed. In particular, it is considered that the measurement of the coefficient of friction of the non-embossed area can be performed even with a very small area.

  According to the present invention as set forth in claim 7, an emboss applied region including a portion on which the surface emboss is formed is disposed in a longitudinal middle portion including the body fluid discharge portion of the liquid permeable top sheet, and the liquid permeable top sheet The sanitary napkin according to any one of claims 1 to 6, wherein an unembossed area not provided with the surface embossing is disposed at the front and rear end portions.

  The invention according to claim 7 shows an example of the arrangement pattern of the specific surface embossed area. Specifically, the body fluid discharged to the body fluid discharge site is arranged by arranging the embossed provision area including the portion on which the surface emboss is formed in the longitudinal middle portion including the body fluid discharge site of the liquid-permeable surface sheet. Diffuses quickly and the front and back end portions in the longitudinal direction become non-embossed regions to suppress diffusion, and in the middle portion in the longitudinal direction including the fluid discharge region, the embossed regions intended to reduce friction Skin contact can be alleviated as much as possible.

  According to the present invention as described above, according to the present invention, the coefficient of friction of the emboss applied region is in both the standing position (0.49 kPa) and the sitting position (1.6 kPa) using the embossed liquid permeable top sheet. By setting the coefficient of friction of the non-embossed area equal to or less than that of the non-embossed area, skin problems can be avoided as much as possible.

The test piece used by the preliminary test is shown, (A) is an embossed non-woven fabric sample, (B) is a surface optical microscope image of the non-embossed non-woven fabric sample. It is the schematic which shows a linear-motion-type sliding friction test apparatus. It is a time-dependent change graph of the friction coefficient of samples A and B. It is a graph which shows the change of the average friction coefficient with respect to the change of the apparent contact pressure of sample A, B. FIG. It is the schematic of the apparatus used for the optical microscope observation test. It is a graph which shows the change of the true contact rate of each sample with respect to the change of a contact pressure. 1 is a plan view of a sanitary napkin 1 according to the present invention. FIG. It is a principal part enlarged plan view of surface embossing 20. As shown in FIG. It is a top view of the sanitary napkin which concerns on a 2nd embodiment. It is the table | surface which showed the nonwoven fabric physical-property list | wrist of sample AD, and a friction coefficient measurement result list. It is a graph which shows the change of the average friction coefficient with respect to the change of the apparent contact pressure of samples C and D. It is a graph which shows the relationship between the fiber diameter of a nonwoven fabric, and a friction coefficient in contact pressure 1.6 kPa.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Pre-test]
First of all, the research conducted by the present inventors in advance for clarifying the influence of non-woven fabric embossing on the friction characteristics will be described in detail.
(1) Test piece As the non-woven fabric used for the test, the first layer is “PP / PE, 1.6 dt (concentric) regular hydrophilicity: 8 gsm”, and the second layer is “PET / PE, 3.3 dt (eccentric) regular A non-woven fabric having a two-layer structure of “hydrophilicity: 17 gsm” was used.

  FIG. 1 shows an optical microscope image of the surface of the non-woven fabric sample used in this study. (A) is a surface optical microscope image of an embossed nonwoven fabric sample (hereinafter referred to as sample A) and (B) is a non-embossed nonwoven fabric sample (hereinafter referred to as sample B). The sample A is embossed with a pattern shown by a thick wavy line in the figure, and this portion is a recess. The depth is 577 μm on average.

(2) Sliding friction test
(a) Test method A friction test was conducted using a linear motion sliding friction test device shown in FIG. An artificial skin piece (contact area: 30 mm × 30 mm) made of polyurethane simulating human skin was used as the counterpart material. The artificial skin piece is attached to the lower part of the load cell, and the non-woven fabric sample is fixed on the stage using a double-sided tape to bring the artificial skin piece into contact. Then, a predetermined load was applied to the top of the load cell by a weight, and a sliding friction test was performed by reciprocating the stage. The test was conducted in the air without lubrication under a sliding speed of 1 mm / s, a sliding distance of 5 mm, and a friction cycle of 10 times. The vertical load was set to 0.49 kPa and 1.6 kPa, assuming a low contact pressure state and a high contact pressure state applied to the napkin mounted at the time of standing and sitting. The sliding direction was the machine direction which is the flow direction of the fibers of the non-woven fabric, and the test was repeated three times under the same conditions to obtain reproducibility. Moreover, in order to simulate an actual use environment, temperature control and humidity control were carried out at a temperature of 36 ± 1 ° C. and a humidity of 60 ± 2% using a heater and a humidifier.

  Standing: 0.49kPa, sitting: 1.6kPa setting, attached to the shorts with an air pack type continuous contact pressure measuring instrument (AIM Techno., Part number: AMI 3037-2), Based on the results of continuous measurement of the contact pressure at standing and at the time of sitting, it was set after considering the constraints from the sliding friction test device. The air pack type continuous contact pressure measuring device is a measuring device which confines air in a flat pack, guides it to a pressure sensor outside the contact with a tube connected to the pack, and measures the contact pressure by a differential pressure with the atmosphere. It has the advantage of being easy to install on a flexible surface.

(b) Experimental Results and Discussion FIG. 3 shows the change over time of the friction coefficient at an apparent contact pressure of 1.6 kPa as a representative example of the change over time of the friction coefficient. In the figure, the solid line and the broken line respectively show the friction coefficients of the sample A and the sample B in the tenth repetition. From the same figure, it can be seen that the value of the coefficient of friction exhibits a large fluctuation range and shows a substantially constant value as the average value in both samples. In order to compare between sample and contact pressure conditions, the average value of the friction coefficient in a period corresponding to 10 to 90% of the slip time at the 10th repetition was used as the average friction coefficient.

  The results of measurement of the coefficient of friction are shown in Table 1 below, and changes in the average coefficient of friction with changes in apparent contact pressure of each sample are shown in FIG. From the figure, for both samples, the coefficient of friction tends to decrease with the increase of the contact pressure. In addition, when the contact pressure is 0.49 kPa, the embossed sample A has a lower coefficient of friction, but when the contact pressure is 1.6 kPa, the sample B has a lower coefficient of friction, and the change in the contact pressure It can be seen that the magnitude of the coefficient of friction is reversed.

Based on the adhesion theory of friction, the coefficient of friction is proportional to the "real contact area" if the shear strength of the adhesion contact surface is constant under the same material and load conditions. Therefore, in order to clarify the change in the true contact area when a load is applied to the non-woven fabric, an optical microscope observation test was performed to estimate the approximate value of the true contact area. In addition, when the thing and the thing are contacting with the said "real contact area", not the apparent contact area but the area of the actual contact part becomes important. The friction itself is a phenomenon which causes a portion which is actually in contact in a microscopic manner, and the area of the portion which is actually in contact is called a "true contact area".
FIG. 5 shows a schematic view of an apparatus used for the optical microscope observation test. As shown in the figure, a glass plate was placed on the non-woven fabric, and a weight having a predetermined weight was placed on the glass plate. The weight of the weight was adjusted to match the apparent contact pressure 2 condition in the friction test. The contact surface of the non-woven fabric and the glass plate was focused by an optical microscope, and the area of the fiber present in the in-focus area was used for evaluation as the true contact area. At the time of observation, temperature was adjusted using a hot plate so that the non-woven fabric sample had the same temperature as 36 ° C. in the friction test. The observation range was 6.5 × 5.0 mm, observation was performed at three randomly selected points, and the average value was used for evaluation.

  FIG. 6 shows the change in the true contact ratio of each sample with respect to the change in contact pressure. The true contact ratio is a ratio of the true contact area to the apparent contact area (area of the imaging range). In the figure, the solid line plot shows the data of sample A, and the wavy plot shows the data of sample B. From the figure, it can be seen that when the contact pressure is 0.49 kPa, the embossed sample A has a smaller true contact ratio than the sample B. On the other hand, in the case of 1.6 kPa, the true contact ratio is smaller in sample B. The large and small changes between the two samples show the same tendency as the change in the average friction coefficient with respect to the contact pressure shown in FIG. 4, which means that the coefficient of friction and the true contact area in the above-mentioned friction cohesion theory Match qualitatively with the relationship. The difference in the relationship between the contact pressure and the contact area due to the presence or absence of the embossing is considered to be due to the deformation characteristics of the side portion of the embossed portion. The embossed side portion has a relatively dense structure because surrounding fibers are drawn in during embossing. Since the embossed bottom portion is a concave portion, it is difficult to contact, and it is considered that the side portion bears the load corresponding to that. In the low load region, the side portion does not significantly deform even when the load is applied, and the embossed bottom portion does not contact, so it is considered that the true contact ratio is lower in the embossed sample A. On the other hand, in the high load area, the side surface can not bear the load, the embossed bottom contacts, and the side surface has fibers densely present, so the contact area tends to be large and the true contact ratio increases. Conceivable.

  From the above, when the nonwoven fabric is embossed, it is expected that the coefficient of friction is reduced in the low load area (0.49 kPa) as in the standing position. On the other hand, in the high load area (1.6 kPa) such as at the time of sitting, it has been found that the increase in the true contact area may increase the friction coefficient.

[This sanitary napkin]
According to the artificial menstrual blood dropping test, it can be understood that the diffusion area is increased by about 60% by applying the embossing, and it is possible to control the diffusion area of the body fluid and to reduce the surface residue of menstrual blood and cages. The effect is recognized by the embossing applied to the liquid top sheet. However, in the sliding friction test, the coefficient of friction of the sample A subjected to embossing during seating is greater than that of the sample B not subjected to embossing, and the magnitude of the coefficient of friction may be reversed due to a change in contact pressure. It has been found.

  In other words, although embossing is effective in controlling the diffusion area of body fluid and reducing the surface residue of menstrual blood and wounds, friction becomes large at the time of sitting, making it easy to cause skin problems such as rubbing. It turns out that there is a drawback.

In the sanitary napkin according to the present invention for coping with this problem, a non-woven fabric is used as the liquid-permeable surface sheet, and a surface emboss is formed on the non-woven fabric at least on the use side in an arbitrary pattern. Yes,
In the liquid-permeable surface sheet, fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used as constituent fibers of the non-woven fabric of the surface layer in contact with the skin,
The coefficient of friction of the liquid-pervious surface sheet was measured using a predetermined sliding friction test method with respect to the embossed region including the portion on which the surface emboss was formed and the non-embossed region not having the surface embossed. When
The measured value under a vertical pressure load condition of 0.49 kPa, assuming a standing position, is such that the coefficient of friction of the embossed region is less than or equal to the coefficient of friction of the unembossed region,
The measured value in the vertical pressure applied state of 1.6 kPa assuming the sitting time is also the one in which the coefficient of friction of the embossed region is equal to or less than the coefficient of friction of the unembossed region.

  Hereinafter, this sanitary napkin will be described in detail.

[Basic configuration of sanitary napkin 1]
The sanitary napkin 1 according to the present invention, as shown in FIG. 7, has a liquid-impervious back sheet 2 made of polyethylene sheet, polypropylene sheet, etc. An absorbent body 4 comprising a sheet 3 and cotton-like pulp or synthetic pulp interposed between the both sheets 2 and 3 and surrounding the absorbent body 4 for improving shape retention and diffusion of the absorbent body 4 A crepe paper 5, a second sheet 6 made of a hydrophilic non-woven fabric laminated on the lower layer side of the liquid-permeable surface sheet 3 and interposed between the liquid-permeable surface sheet 3 and the crepe paper 5; The non-woven fabrics 7 and 7 are disposed along the longitudinal direction. At the front and rear end edges of the absorbent body 4 in the longitudinal direction of the napkin, the outer edges of the liquid-impervious backsheet 2 and the liquid-permeable topsheet 3 are adhesive such as hot melt, heat seal, etc. The liquid-impervious backsheet 2 and the side non-woven fabric 7 which are joined by adhesive means and which extend laterally beyond the edge of the absorbent body 4 at the side edges thereof are made of an adhesive such as a hot melt or heat The outer peripheral flap part F which is joined by adhesion | attachment means, such as a seal | sticker, and the absorber 4 does not exist is formed in outer periphery.

  The liquid-impervious back sheet 2 is a sheet material having at least water blocking properties such as an olefin-based resin sheet such as polyethylene or polypropylene, etc. In addition to this, a laminated non-woven fabric obtained by laminating non-woven fabric on polyethylene sheet etc. A non-woven fabric sheet (in this case, a liquid-impervious back sheet is composed of the waterproof film and the non-woven fabric) can be used after the liquid-imperviousness is substantially ensured by interposing the waterproof film. In recent years, it has tended to use what has moisture permeability from a viewpoint of muzzle prevention. This water-impervious and moisture-permeable sheet material is a microporous sheet obtained by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet in a uniaxial or biaxial direction. It is.

  Next, a porous or non-porous non-woven fabric is preferably used as the liquid-permeable top sheet 3. The material fibers constituting the non-woven fabric can be, for example, synthetic fibers such as olefins, polyesters, polyamides, etc. such as polyethylene or polypropylene, regenerated fibers such as rayon or cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a lace method, a spun bond method, a thermal bond method, a meltblown method, a needle punch method or the like can be used. Among these processing methods, the spun lace method is excellent in flexibility, the spun bond method is excellent in drapability, and the thermal bond method and the air through method are excellent in bulk and softness. The synthetic fiber may be, for example, a polyolefin type such as polyethylene or polypropylene, a polyester type such as polyethylene terephthalate or polybutylene terephthalate, a polyamide type such as nylon, or a mixture of two or more of these copolymers. . In addition, composite fibers such as core-sheath fibers, side-by-side fibers, and split-type fibers, in which fibers having a high melting point are cored and fibers having a low melting point are sheathed, can also be used.

  In the liquid-permeable surface sheet 3, as described in detail later, surface embossments 20 are formed in an arbitrary pattern at least on the use surface side of the nonwoven fabric. The illustrated example is a surface embossing 20 consisting of a combination of a predetermined wave pattern and a dot pattern. The liquid-permeable top sheet 3 will be described in more detail later.

  The absorber 4 interposed between the liquid-impervious backsheet 2 and the liquid-permeable topsheet 3 is made of, for example, fluff pulp and a water-absorbing polymer. The water-absorbing polymer is mixed, for example, as granular powder in the pulp constituting the absorbent. Examples of the pulp include cellulose fibers such as chemical pulp and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate, and softwood pulp having a longer fiber length than hardwood pulp functions and It is suitably used in terms of price.

  In addition, synthetic fibers may be mixed in the absorber 4. Examples of the synthetic fibers include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, copolymers of these, and the like. It may be a mixture. In addition, composite fibers such as core-sheath fibers, side-by-side fibers, and split-type fibers, in which fibers having a high melting point are cored and fibers having a low melting point are sheathed, can also be used. In the case of a hydrophobic fiber, it is desirable to use the synthetic fiber surface-treated with a hydrophilizing agent so as to have an affinity for body fluid.

  When the crepe paper 5 surrounding the absorber 4 is provided as in this example, the crepe paper 5 intervenes between the liquid-pervious surface sheet 3 and the absorber 4 as a result, and the absorbability is improved. The crepe paper 5 which is superior to the above makes it possible to rapidly diffuse the body fluid and to prevent the regurgitation of menstrual blood and the like.

  The second sheet 6 made of a hydrophilic non-woven fabric laminated on the lower layer side of the liquid-permeable surface sheet 3 is, for example, synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, polyamides, rayon and cupra It can be a regenerated fiber or a natural fiber such as cotton, and a non-woven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, a meltblown method or a needle punch method can be used. In order to impart hydrophilicity, a method of causing a compound having a hydrophilic group, for example, an oxidized product of polyethylene glycol, etc. to coexist in the production process of the synthetic fiber, or treating with a metal salt such as stannic chloride, The synthetic fiber can be made to swell or become porous by a method of partially dissolving the surface to make it porous and depositing a metal hydroxide, etc., and applying capillary action to impart hydrophilicity. The second sheet 6 is preferably joined to the liquid-permeable top sheet 3.

  On the other hand, side non-woven fabrics 7 and 7 are provided on both sides of the surface of the present sanitary napkin 1 along the longitudinal direction and over substantially the entire length of the napkin 1, and a part of the side non-woven fabrics 7 and 7 is Wing-shaped flaps W, W are formed by the laterally extending and a part of the liquid-impervious back sheet 2 also extending laterally.

  As the side nonwoven fabric 7, a water repellent treated nonwoven fabric or a hydrophilic treated nonwoven fabric can be used from the viewpoint of the function to be emphasized. For example, if importance is attached to the function of preventing menstrual blood and vaginal discharge from permeating, or enhancing the feel of the touch, a water repellent treatment coated with a silicone, paraffin or alkylchromic chloride water repellent etc. It is desirable to use a non-woven fabric. Also, if emphasis is placed on the absorbability of the wing-shaped flap W, such as menstrual blood, a method of causing a compound having a hydrophilic group, for example, an oxidized product of polyethylene glycol, etc. to coexist in the production process of synthetic fiber Treated with a metal salt such as stannic chloride, and the surface is partially dissolved to make the surface porous and deposit metal hydroxide, etc. to make the synthetic fiber swell or porous, and apply capillary action to make it hydrophilic It is desirable to use a hydrophilic treated nonwoven fabric given

<Liquid permeable surface sheet 3>
In the present invention, a non-woven fabric is used particularly as a liquid-permeable surface sheet, and a surface emboss 20 is formed in an arbitrary pattern at least on the use surface side of the non-woven fabric.

  The surface emboss 20 shown in FIG. 7 is formed on the entire surface of the liquid-permeable surface sheet 3 but is formed in a partial area including at least a body fluid discharge site. The surface emboss 20 can be formed by a pattern consisting of straight lines, dotted lines, wavy lines, curves or a combination thereof. The illustrated example is formed by the following wave pattern.

  The wavelike pattern, as shown in detail in FIG. 9, in a plan view, along the substantially longitudinal direction of the napkin, the projecting portion 21 to one side of the napkin width direction and the projecting portion 22 to the other side Are alternately arranged in the width direction of the napkin, and the first wave pattern 23 alternately repeating the above and the second wave pattern 24 obtained by inverting the first wave pattern 23 in the width direction of the napkin. . By providing the surface emboss 20 of such a wavelike pattern on the liquid-pervious surface sheet 3, it becomes possible to diffuse the body fluid in the longitudinal direction, and at the same time the liquid-pervious surface sheet starting from the protrusions 21 and 22 3 is likely to be deformed along the shape of the body, and the occurrence of wrinkles and deflection due to the liquid-permeable top sheet 3 not conforming to the shape of the body can be prevented.

  As shown in FIG. 9, by providing the surface embossing 20 of the wavelike pattern, the wide part 25 and the narrow part 26 with different separation width between the first wavelike pattern 23 and the second wavelike pattern 24. And are alternately formed repeatedly in the longitudinal direction of the napkin.

  The liquid-permeable surface sheet 3 is bonded to the lower planar second sheet 6 by an adhesive such as heat fusion or hot melt at least at the contact surface with the bottom surface of the surface emboss 20 of the wave pattern. It is integrated with the seat 6.

  On the other hand, in order to reduce the surface residue of the body fluid in the wide portion 25 and to reduce the contact area with the skin, as in the illustrated example, dot-shaped embossments 27 are provided on all or part of the wide portion 25. Is preferred.

  The surface emboss 20 of the wavelike pattern is such that the wavelike pattern is intermittently provided in the substantially longitudinal direction of the napkin by forming periodic intermittent portions 28, 28 ... in accordance with the period of the wavelike pattern. Can. In the example of the figure, the intermittent part 28 is provided in the top part of the projecting part 22 to the other side of the napkin width direction. By providing the intermittent portion 28, the liquid-permeable surface sheet 3 is easily deformed along the shape of the body with the intermittent portion 28 as a base point. If the intermittent length of the intermittent portion 28 is too large, the continuity of the wave pattern is significantly impaired, and the effect as the above-mentioned base point is lost. Therefore, the intermittent length of the intermittent portion 28 in the napkin longitudinal direction Is preferably 1 mm or less.

  The liquid-permeable top sheet 3 is a fiber having a fiber diameter of 1.9 dt or more and 3.0 dt or less as a constituent fiber of a non-woven fabric in contact with the skin. By setting the fiber diameter to 1.9 dt or more, the surface of the liquid-permeable surface sheet 3 is subjected to the predetermined sliding friction test method as shown in the section of <Sliding friction test of liquid-permeable surface sheet> described later. When the coefficient of friction is measured with respect to the embossed region including the portion on which the emboss 20 is formed and the non-embossed region not having the surface emboss 20, as shown in FIG. The measured value in the vertical pressure load condition of 0.49 kPa is the vertical pressure load condition of 1.6 kPa assuming that the coefficient of friction of the embossed region is equal to or less than the coefficient of friction of the non-embossed region and assuming seating. The measured value of で き る can also be set so that the coefficient of friction of the embossed region is less than or equal to the coefficient of friction of the non-embossed region.

  That is, by setting the fiber diameter of the non-woven fabric to 1.9 dt or more, the magnitude of the coefficient of friction varies with the change in the contact pressure in the magnitude relationship between the coefficient of friction at standing (0.49 kPa) and the coefficient of friction at seating (1.6 kPa). Can be prevented, and in both the standing and sitting maintenance cases, the coefficient of friction of the embossed area can be made equal to or less than that of the non-embossed area, thus causing skin problems It becomes possible to prevent or alleviate. In addition, the embossing 20 of the said embossing provision area | region is a recessed part dented in the non-skin side, and the said embossing non-application area | region comprises the plane.

  Moreover, about the upper limit side numerical value: 3.0 dt of the fiber diameter of the nonwoven fabric used as the liquid-permeable surface sheet 3, when the fiber diameter is increased too much, the space between the fibers increases and the liquid permeability is improved. Since a problem is likely to occur, the upper side of the surface sheet 3 of this type of sanitary napkin is generally taken as the upper limit value.

  The depth of the surface embossing 20 is desirably 400 μm to 700 μm, preferably 500 μm to 600 μm in average value.

The sliding friction test method is a friction test carried out in accordance with the following procedures (1) to (6).
(1) A friction test is performed using a direct acting sliding friction test apparatus (Trinity Lab Co., Ltd. Speed fluctuation friction testing machine Type: μv-1000).
(2) Using an artificial skin piece made of polyurethane simulating human skin, attach the artificial skin piece to the lower part of the load cell, fix the non-woven fabric sample on the stage, and bring the artificial skin piece into contact.
(3) The weight is applied to the upper part of the load cell by the weight so that the vertical load is equivalent to the apparent contact pressure (0.49 kPa in standing position, 1.6 kPa in sitting position) applied to the attached napkin when standing and sitting. The sliding friction test is performed by loading and reciprocating the stage.
(4) The test is conducted in the air without lubrication under a sliding speed of 1 mm / s, a sliding distance of 5 mm, and a friction cycle of 10 times.
(5) The sliding direction is the machine direction which is the flow direction of the fibers of the nonwoven fabric, and the test is repeated three times under the same conditions to obtain reproducibility.
(6) The average value of the coefficient of friction in a period corresponding to 10 to 90% of the slip time at the 10th repetition is used as the coefficient of friction.

  When the surface emboss 20 is formed on the entire surface of the surface sheet according to the present embodiment, the measurement of the coefficient of friction for the non-embossed area not having the surface emboss applied is performed between the embossing and the embossing. The coefficient of friction may be measured with the unapplied area as the measurement target, but if the area to be measured is particularly narrow, reduce the area of the artificial skin piece of the sliding friction test device or reduce the sliding distance. It is possible to cope. Alternatively, if it is possible to obtain a nonwoven sheet of the same material before embossing, it may be possible to conduct a friction test on the obtained nonwoven.

  The liquid-permeable top sheet 3 is preferably a two-layer non-woven fabric integrally provided with a crimped fiber layer on the lower side thereof separately from the layer in contact with the skin. Specifically, it is a non-woven fabric having a two-layer structure consisting of an upper layer and a lower layer, wherein the upper layer is made of a polymer polymer and fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used. A non-woven fabric can be used in which a crimped fiber having a fiber diameter of 4.0 dt or more and 7.0 dt or less is used. The lower crimped fiber layer can elastically support the vertical compressive force, thereby improving the cushioning property in the thickness direction with respect to the non-woven fabric, the compression followability, the deformation resistance when subjected to the compressive force, etc. It becomes possible.

  Furthermore, as a preferred example of the two-layer structure, a non-woven fabric having a two-layer structure comprising an upper layer and a lower layer is used, and the upper layer is a short with a diameter of 1.9 dt or more and 3.0 dt or less. The lower layer is a crimped fiber comprising polyethylene terephthalate as a core and polyethylene sheath as a core, the thickness of the fiber is a short fiber of 4.0 dt or more and 7.0 dt or less, and the upper layer is 40% or less by weight of the whole It can be a certain nonwoven fabric. In this preferred embodiment, a core-sheath type fiber having polyethylene terephthalate as a core material is used. Polyethylene terephthalate is relatively higher in shape stability than polyolefin fibers, and can improve cushioning properties, compression followability, and resistance to deformation when subjected to a compressive force.

  In manufacturing the liquid-pervious surface sheet 3 on which the surface emboss 20 is formed, for example, an embossment in which the first embossing roll, the second embossing roll, and the anvil roll having a smooth surface are arranged in the longitudinal direction from the lower side. A roll device is used. The first embossing roll and the second embossing roll are combined, and the liquid-pervious surface sheet is passed between the embossing rolls to give uneven embossing, and the second embossing roll and the anvil roll are The second sheet 6 of the lower layer is made to enter between the second embossing roll and the anvil roll while passing the liquid-pervious surface sheet 3, and the liquid-pervious top sheet 3 and the second sheet 6 are superposed, At least one side of the emboss roll and the anvil roll is kept heated to a predetermined temperature, and the bottom surface of the concave portion of the liquid-pervious surface sheet 3 and the second sheet 6 are joined by heat fusion. The liquid-pervious surface sheet 3 and the second sheet 6 may be joined by an adhesive such as hot melt.

  The assembly of the above-mentioned sanitary napkin 1 is a liquid-permeable surface sheet 3 in which an absorbent body 4 surrounded by a crepe paper 5 and a surface emboss 20 are formed on a liquid-impervious back sheet 2 cut into a predetermined product shape. The second sheet 6 and the side non-woven fabric 7 are laminated, and the liquid-pervious surface sheet 3, the second sheet 6 and the side non-woven fabric 7 are simultaneously cut into a predetermined shape.

Second Embodiment
In the sanitary napkin 1 of the above embodiment, the surface emboss 20 is formed over the entire surface of the liquid-pervious surface sheet 3, but the surface emboss 20 can be partially formed. For example, as shown in FIG. 10, an emboss applied area including a portion in which the surface emboss 20 is formed is disposed at a longitudinal middle portion including the body fluid discharge site H of the liquid permeable top sheet 3. The non-embossed area where the surface emboss is not imparted may be arranged at the front and rear end portions of the sheet 3.

  While diffusing the body fluid discharged to the body fluid discharge site H in the longitudinal direction quickly, the longitudinal longitudinal end portions are made to be non-embossed regions to suppress the diffusion, and the longitudinal middle portion including the body fluid discharge site H Is an embossed area where friction is reduced, and by applying this to the vulva, it is possible to alleviate skin problems as much as possible.

<Sliding Friction Test of Permeable Surface Sheet>
In the case where the contact pressure is standing (0.49 kPa) in the <preliminary test> described above, the case where the contact pressure is seated (1.6 kPa) although the coefficient of friction of the embossed sample A is smaller In the case of the sample B which was not embossed, the coefficient of friction was smaller, and the magnitude relationship of the coefficient of friction was reversed due to the change in the contact pressure. As a result of repeating various examinations and tests, it came to the conclusion that the fiber diameter of the non-woven fabric layer in contact with the skin is largely related.

  Then, the result of having performed the same sliding friction test with respect to the test piece which changed the fiber diameter is explained in full detail.

(1) Test piece The material of the non-woven fabric is the first layer "PET / PE, 2.2 dt (concentric) regular hydrophilicity: 8 gsm", the second layer "PET / PE, 6.6 dt (eccentric) regular hydrophilicity: 17 gsm Of the two-layer structure.

  With respect to this non-woven fabric, the sample subjected to embossing shown in FIG. 1A is referred to as sample C, and the sample not subjected to embossing is referred to as sample D. The embossing depth is 577 μm on average.

  The difference from the test piece used in the above <pre-test> is that the material of the first layer was changed from PP / PE to PET / PE, and the fiber diameter was changed from 1.6 dt to 2.2 dt, and 2 layers The fiber diameter of the eye is changed from 3.3 dt to 6.6 dt. For easy comparison of the physical property values of the samples A to D, they are shown in the list of FIG.

  The friction test was performed on the sample C and the sample D by the same method as the sliding friction test performed in <preliminary test>. The results are shown in the following Table 2 and graphically shown in FIG.

  In these samples C and D, when the contact pressure is standing (0.49 kPa), the embossed sample C has a smaller coefficient of friction and the contact pressure is seated (1.6 kPa). The coefficient of friction of the embossed sample C was smaller, and the change in contact pressure did not reverse the magnitude relationship of the coefficient of friction.

  In the present invention, the contact pressure at the time of sitting is set to 1.6 kPa, but it has been found that the contact pressure may be up to 4.9 kPa depending on the posture, so the lower column of the table in FIG. In each of the samples A to D, the value of the coefficient of friction when the contact pressure is 4.9 kPa is shown. As with seating (1.6 kPa), the relative relationship between the samples A and B is that the coefficient of friction is larger in the presence of embossing than in the absence of embossing, as in the case of seating (1.66 kPa). Between samples C and D, the relative relationship in which the coefficient of friction is smaller in the presence of embossing than in the absence of embossing when seated shows the same tendency.

  As a result of obtaining the above-mentioned findings, if the fiber diameter is as follows next, even when the contact pressure is sitting (1.6 kPa), the coefficient of friction of the embossed sample C becomes smaller, and the contact pressure Whether the magnitude relationship of the coefficient of friction is not reversed due to the change of Δ is derived from the results of the friction test of the samples A to D according to the following procedure.

  As shown in FIG. 13, on the graph in which the horizontal axis represents the fiber diameter (dt) of the non-woven fabric and the vertical axis represents the friction coefficient, the fiber diameter 1.6 dt for sample A (with embossing) and sample B (without embossing). The coefficient of friction 0.27 of sample A (with embossing) and the coefficient of friction 0.25 of sample B (without embossing) are plotted at the contact pressure of 1.6 kPa. And for sample C (with embossing) and sample D (without embossing), the friction coefficient of sample C (with embossing) and friction of sample D (without embossing) at a contact pressure of 1.6 kPa at a fiber diameter of 2.2 dt Plot the coefficient 0.24.

  And while connecting sample A (with embossing) and sample C (with embossing) by a line, connecting sample B (without embossing) and sample D (without embossing) with a line. It is inferred that the position of the point of intersection of these two straight lines is the fiber diameter when the coefficient of friction at a contact pressure of 1.6 kPa has the same value in the case of embossing and without embossing.

  Therefore, the fiber diameter at the intersection of the two straight lines from FIG. 13 is 1.9 dt, so by setting the fiber diameter of the non-woven fabric in contact with the skin at 1.9 dt or more, standing (0.49 kPa) and sitting (1.6 kPa) In both cases, it has been found that the coefficient of friction of the embossed region can be less than or equal to the coefficient of friction of the unembossed region.

  In addition, assuming that the fiber diameter of the non-woven fabric in contact with the skin is 1.9 dt, the coefficient of friction of the embossed region is predicted to be the same value as the coefficient of friction of the unembossed region when seated (1.6 kPa). In order to make the coefficient of friction of the embossed region smaller than the coefficient of friction of the unembossed region, the fiber diameter of the non-woven fabric in contact with the skin is preferably 2.0 dt or more.

  DESCRIPTION OF SYMBOLS 1 ... Sanitary napkin, 2 ... Liquid impermeable back sheet, 3 ... Liquid permeable surface sheet, 4 ... Absorber, 5 ... Crepe paper, 6 ... Second sheet, 7 ... Side nonwoven fabric, 20 .. Surface embossing, 21 .. Projections to one side, 22: Projections to the other side, 23: First wave pattern, 24: second wave pattern, 25: wide area, 26: narrow area, 27: dot-like embossing

Claims (7)

In a sanitary napkin in which an absorbent is interposed between a liquid-permeable top sheet and a back sheet,
A non-woven fabric is used as the liquid-pervious surface sheet, and a surface emboss is formed on the non-woven fabric at least on the use side in an arbitrary pattern,
In the liquid-permeable surface sheet, fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used as constituent fibers of the non-woven fabric of the surface layer in contact with the skin,
The coefficient of friction of the liquid-pervious surface sheet was measured using a predetermined sliding friction test method with respect to the embossed region including the portion on which the surface emboss was formed and the non-embossed region not having the surface embossed. When
The measured value under a vertical pressure load condition of 0.49 kPa, assuming a standing position, is such that the coefficient of friction of the embossed region is less than or equal to the coefficient of friction of the unembossed region,
The measured value in the vertical pressure load state of 1.6 kPa supposing the time of seating also has a coefficient of friction of the above-mentioned emboss applied area below the coefficient of friction of the above-mentioned non-emboss applied area. The sanitary napkin according to claim 1, wherein the sliding friction test method is a friction test carried out in accordance with the following procedures (1) to (6).
(1) A friction test is performed using a direct acting sliding friction test apparatus (Trinity Lab Co., Ltd. Speed fluctuation friction testing machine Type: μv-1000).
(2) Using an artificial skin piece made of polyurethane simulating human skin, attach the artificial skin piece to the lower part of the load cell, fix the non-woven fabric sample on the stage, and bring the artificial skin piece into contact.
(3) The weight is applied to the upper part of the load cell by the weight so that the vertical load is equivalent to the apparent contact pressure (0.49 kPa in standing position, 1.6 kPa in sitting position) applied to the attached napkin when standing and sitting. The sliding friction test is performed by loading and reciprocating the stage.
(4) The test is conducted in the air without lubrication under a sliding speed of 1 mm / s, a sliding distance of 5 mm, and a friction cycle of 10 times.
(5) The sliding direction is the machine direction which is the flow direction of the fibers of the nonwoven fabric, and the test is repeated three times under the same conditions to obtain reproducibility.
(6) The average value of the coefficient of friction in a period corresponding to 10 to 90% of the slip time at the 10th repetition is used as the coefficient of friction.   The liquid-pervious surface sheet is a non-woven fabric having a two-layer structure comprising an upper layer and a lower layer, and the upper layer is made of a polymer polymer and fibers having a fiber diameter of 1.9 dt or more and 3.0 dt or less are used. The sanitary napkin according to any one of claims 1 and 2, wherein a crimped fiber having a fiber diameter of 4.0 dt or more and 7.0 dt or less is used as a material of a high molecular weight polymer.   The liquid-pervious surface sheet is a non-woven fabric having a two-layer structure including an upper layer and a lower layer, and the upper layer is a short fiber having a diameter of 1.9 dt or more and 3.0 dt or less. The nonwoven fabric wherein the lower layer is a crimped fiber comprising a polyethylene terephthalate core and a polyethylene sheath and the thickness of the fiber is a short fiber of 4.0 dt or more and 7.0 dt or less and the upper layer is 40% or less by weight of the whole The sanitary napkin according to any one of claims 1 and 2, which is used.   The sanitary napkin according to any one of claims 1 to 4, wherein the depth of the surface embossing is 400 μm or more and 700 μm or less.   The sanitary napkin according to any one of claims 1 to 5, wherein the surface embossment is formed in an area including at least a body fluid discharge site.   An emboss applied area including a portion in which the surface emboss is formed is disposed in a longitudinal direction intermediate portion including a body fluid discharge portion of the liquid permeable surface sheet, and the surface emboss is applied to front and rear end portions of the liquid permeable surface sheet. The sanitary napkin according to any one of claims 1 to 6, wherein an unembossed non-embossed area is disposed.