JP2021003512A - Absorbent article - Google Patents

Abstract

To provide an absorbent article capable of reducing a load of an operator when exchanging an absorbent article such as a disposable diaper.SOLUTION: An absorbent article includes a front surface sheet arranged on a skin facing surface, a rear surface sheet arranged on a skin non-facing surface, and an absorbent core arranged between both sheets, and has a length direction corresponding to a cross direction of a wearer, and a width direction orthogonal to the length direction. The absorbent article further has an abdominal side part arranged on the abdominal side of the wearer, a back side part arranged on the back side of the wearer, and a crotch part positioned therebetween. In the absorbent article, at least in the back side parts of two absorbent articles, a coefficient of static friction μ11 is 0.43 or less, in a length direction between the rear surface sheet of one absorbent article and the front surface sheet of the other absorbent article.SELECTED DRAWING: Figure 4

Description

The present invention relates to absorbent articles.

In general, the task of changing absorbent articles, such as disposable diapers, is a heavy burden on the operator. For example, when replacing a used diaper, the dorsal part of the diaper is caught between the wearer wearing the diaper and the workbench, and a large force is required to pull out the diaper. In particular, the heavier the diaper wearer, the greater the force required to pull out the diaper.

In addition, when replacing a used diaper by laying a cloth such as a towel between the wearer and the workbench, the cloth may be pulled out or bent when the diaper is pulled out. There is a risk of contaminating the table.

In addition, when the diaper is pulled out, the wearer's waist and buttocks may rub against the diaper, causing skin troubles.

On the other hand, in order to reduce skin troubles of the wearer, disposable diapers in which an oil agent such as a lubricant is applied to the surface facing the skin are known. For example, Patent Document 1 discloses a pants-type disposable diaper that has a skin-facing surface and a lubricant is applied around a leg opening. Further, Patent Document 2 discloses a deployable disposable diaper in which an oil agent for reducing friction is applied to a surface facing the skin.

Further, in Patent Document 3, in order to reduce skin troubles caused by the bulging portion of the outer surface side surface of the diaper (non-skin facing surface of the diaper) rubbing against the inner crotch of the wearer, the non-skin of the lower crotch is described. Disposable diapers having an oil agent for reducing friction are disclosed on a part or the entire surface of the facing surface.

Further, Patent Document 4 discloses a disposable diaper having an average deviation SMD of the surface roughness of the outer layer sheet of 3.20 μm or less and an average deviation MMD of the friction coefficient of 0.0085 or less.

Further, in Patent Document 5, at least a part of the sheet on the side facing the skin contains a friction reducing agent, and the friction coefficient of the portion containing the friction reducing agent is 40 with respect to the friction coefficient of the portion not containing the friction reducing agent. Water-absorbent articles of% or less are disclosed.

Further, Patent Document 6 discloses a disposable diaper in which the coefficient of dynamic friction of the surface of the coating sheet in contact with the hook tape of the mechanical fastener or the fixing portion made of the adhesive layer is 0.85 or more.

Japanese Unexamined Patent Publication No. 2006-271421 Japanese Unexamined Patent Publication No. 2004-305598 Japanese Unexamined Patent Publication No. 2010-131081 Japanese Unexamined Patent Publication No. 2016-005545 Japanese Patent No. 6063236 Japanese Patent No. 5420995

When exchanging used diapers, the unused diapers are deployed and placed between the wearer wearing the used diapers and the workbench, the used diapers are pulled out, and the wearer wears the unused diapers. Sometimes. When the used diaper is replaced in this way, when the used diaper is pulled out, the unused diaper is also pulled out, which may lead to a decrease in work efficiency. Further, Patent Documents 1 to 6 describe a technique capable of reducing friction between the used diaper and the unused diaper for the purpose of improving work efficiency when exchanging the used diaper, for example, Techniques such as applying an oil agent to the non-skin facing surface of the back side of the diaper are not disclosed.

An object of the present invention is to provide a disposable diaper capable of reducing the burden on the operator when exchanging an absorbent article such as a disposable diaper.

The present invention includes a front surface sheet arranged on the skin facing surface, a back surface sheet arranged on the non-skin facing surface, and an absorbent core arranged between these two sheets, and the longitudinal direction corresponding to the front-back direction of the wearer. Absorption having a width direction orthogonal to the longitudinal direction and having a ventral portion arranged on the ventral side of the wearer, a dorsal portion arranged on the dorsal side of the wearer, and a crotch located between them. A sex article, the absorbent article, in at least the dorsal portion of the two absorbent articles, in the longitudinal direction between the back sheet of one absorbent article and the front sheet of the other absorbent article. It provides an absorbent article having a static friction coefficient μ11 of 0.43 or less.

According to the absorbent article of the present invention, it is possible to reduce the burden on the operator when exchanging the absorbent article such as a disposable diaper.

FIG. 1 is a plan view of a non-skin facing surface showing a stretched state of a deployable disposable diaper according to an embodiment of the present invention. FIG. 2 is a plan view of a skin-facing surface showing a stretched state of a deployable disposable diaper according to an embodiment of the present invention. FIG. 3 is a sectional view taken along line X1-X1 of FIG. FIG. 4 is a diagram for explaining a method of exchanging the diaper 1. FIG. 5 is a schematic view showing a method for measuring the static friction coefficient μ11 using a tensile tester.

Hereinafter, a preferred embodiment of the deployable disposable diaper, which is an absorbent article of the present invention, will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the deployable disposable diaper 1 (hereinafter, also simply referred to as “diaper 1”) has a dorsal side A, a ventral side B, and an inseam C. Note that FIG. 1 illustrates the non-skin facing surface O of the diaper 1. FIG. 2 illustrates the skin-facing surface I of the diaper 1. FIG. 3 is a sectional view taken along line X1-X1 of FIG. In the present specification, the "skin facing surface I" is the surface of the diaper 1 facing the skin side of the wearer wearing the diaper 1, and the "non-skin facing surface O" is the skin side of the wearer. This is the side of the diaper 1 facing the opposite side (clothing side).

As shown in FIGS. 1 and 2, the diaper 1 is formed symmetrically with respect to the center line CL. Therefore, in the following description, the symmetrical portion will be mainly described on the right side.

As shown in FIGS. 1 to 3, the diaper 1 includes a liquid-permeable first sheet 2, a liquid-impermeable second sheet 3, and an absorbent core 4 arranged between the sheets 2 and 3. It includes an absorbent main body 5 having a third sheet 61 and an outer packaging material 6 having a fourth sheet 62. As shown in FIG. 3, the outer packaging material 6 is fixed by arranging the third sheet 61 on the non-skin facing surface O of the absorbent main body 5. The outer packaging material 6 of the diaper 1 has a dorsal side A, a ventral side B, and a crotch C in the longitudinal direction (hereinafter referred to as “Y direction”; Y direction: a direction parallel to the center line CL). doing.

As shown in FIG. 1, the outer packaging material 6 has constricted portions 6d and 6d whose side edges are constricted inward in the central portion in the longitudinal direction (Y direction), and the outer packaging material 6 has constricted portions 6d and 6d in the longitudinal direction (Y direction). ) Is wider than the width of the central portion in the longitudinal direction (Y direction). The pair of constricted portions 6d and 6d are portions arranged around the legs of the pair of wearers.

Here, the inseam C is a portion arranged in the crotch portion of the wearer, and as shown in FIG. 1, indicates a region sandwiched between the pair of constricted portions 6d and 6d. The dorsal part A is a part arranged on the dorsal side of the wearer when the diaper 1 is worn, and the ventral part B is a part arranged on the ventral side of the wearer. As shown in FIG. 1, the dorsal side A and the ventral side B indicate regions extending from the inseam C in the longitudinal direction (Y direction) in the anteroposterior direction. As shown in FIG. 1, the dorsal side A, the ventral side B, and the inseam C are the portions divided into three equal parts in the longitudinal direction in the unfolded state of the absorbent article.

As shown in FIGS. 1 to 3, the outer packaging material 6 is formed between the fourth sheet 62 forming the outer surface of the diaper 1, the third sheet 61 arranged on the inner surface side of the fourth sheet 62, and both sheets 61 and 62. It is formed of a plurality of waist elastic members 63 arranged and fixed in the above and a plurality of leg elastic members 64 for forming leg gathers. The fourth sheet 62 and the third sheet 61 have the same shape and the same size. A plurality of waist elastic members 63 are provided on the dorsal side A and the ventral side B, and each waist elastic member 63 is arranged and fixed in the width direction (X direction) in an extended state. .. The width direction (X direction) is orthogonal to, for example, the longitudinal direction (Y direction). As shown in FIG. 1, the plurality of leg elastic members 64 are arranged along a pair of constricted portions 6d and 6d, which are portions arranged around the wearer's legs. Each leg elastic member 64 is arranged and fixed in an extended state.

A pair of left and right fastening tapes 8 and 8 are provided on both the left and right sides of the dorsal side portion A. A target tape 9 for fastening the fastening tape 8 is provided on the outer surface of the ventral side portion B.

As shown in FIG. 3, the absorbent main body 5 is interposed between the liquid-permeable first sheet 2, the liquid-impermeable (including water-repellent) second sheet 3, and both sheets 2 and 3. It has a liquid-retaining absorbent core 4 and is substantially vertically elongated. As shown in FIGS. 1 and 2, the absorbent main body 5 is arranged so as to extend from the dorsal side A to the ventral side B of the outer packaging material 6, and both ends of the absorbent main body 5 in the longitudinal direction (Y direction). The portions are located at positions recessed inward in the longitudinal direction (Y direction) from both ends in the longitudinal direction (Y direction) of the outer packaging material 6. As shown in FIG. 3, in the absorbent main body 5, the non-skin facing surface of the second sheet 3 of the absorbent main body 5 is a third sheet of the outer packaging material 6 by a joining method using an adhesive, a heat seal, an ultrasonic seal or the like. It is joined to the skin facing surface side of 61.

As shown in FIG. 3, lateral cuffs 51 and 51 made of a liquid-impermeable or water-repellent and breathable material are provided on both sides of the absorbent body 5 in the longitudinal direction (Y direction). There is. An elastic member 52 for forming the side cuffs is arranged and fixed in an extended state in the vicinity of the free end portion of each side cuff 51. The side cuffs 51 stand up on the free end side when the diaper is worn, and can prevent the outflow of excrement in the width direction (X direction) of the absorbent body 5. As shown in FIG. 3, in the side cuff 51 forming sheet, a portion 51a having a predetermined width outside the width direction (X direction) of the absorbent body 5 is caught in the non-skin facing surface side of the absorbent core 4. It is fixed between the absorbent core 4 and the second sheet 3. The portion 51a having a predetermined width may be fixed between the second sheet 3 and the outer packaging material 6.

As shown in FIGS. 1 and 3, the fourth seat 62 is the furthest away from the wearer wearing the diaper 1. The surface of the fourth sheet 62 opposite to the third sheet 61 corresponds to the non-skin facing surface O of the diaper 1. As shown in FIGS. 2 and 3, the surface of the first sheet 2, the elastic member 52 for forming the lateral cuffs, and the third sheet 61 opposite to the fourth sheet 62 is the skin of the diaper 1. Corresponds to the facing surface I.

Here, the sheets arranged on the non-skin facing surface О of the diaper 1 are collectively referred to as a back surface sheet. That is, in the diaper 1 shown in FIGS. 1 and 3, the fourth sheet constitutes the back surface sheet. The sheets arranged on the skin-facing surface I of the diaper 1 are collectively referred to as a surface sheet. That is, in the diaper 1 shown in FIGS. 2 and 3, a first sheet 2, an elastic member 52 for forming lateral cuffs, and a part of the third sheet 61 constitute a surface sheet. As described above, the front surface sheet and the back surface sheet may each be composed of one sheet, or may be composed of a combination of a plurality of sheets. Further, the diaper 1 has an absorbent core 4 arranged between the front surface sheet and the back surface sheet, but in all of the plurality of sheets constituting the front surface sheet and the back surface sheet, the absorbent core 4 is arranged between the two sheets. It does not have to be, and it is sufficient that the absorbent core 4 is arranged between the two sheets in a part of the plurality of sheets.

The dorsal portion A has a non-skin facing surface AO. The non-skin facing surface AO corresponds to the entire region shown by diagonal lines in FIG. 1 and is included in the above-mentioned non-skin facing surface O. In one example, the non-skin facing surface AO is a region symmetrical with respect to the center line CL in the back side portion A, and has a width equivalent to that of the absorbent body 5 in the width direction (X direction). .. The non-skin facing surface AO of the dorsal side A is, for example, a portion of the non-skin facing surface AO1 of the portion overlapping the waist elastic member 63 and a portion overlapping the absorbent body 5 that is close to the waist elastic member 63. It has a non-skin facing surface AO2, a portion of the waist elastic member 63 that overlaps with the absorbent body 5, and a non-skin facing surface AO3 between the absorbent body and the overlapping portion.

The dorsal side A has a skin-facing surface AI. The skin facing surface AI corresponds to the entire region shown by the diagonal line in FIG. 2, and is included in the skin facing surface I described above. In one example, the skin-facing surface AI is a region symmetrical with respect to the center line CL on the back side portion A, and has a width equivalent to that of the absorbent main body 5 in the width direction (X direction). The skin-facing surface AI is a region that comes into contact with the non-skin-facing surface AO when the two deployable disposable diapers 1 are stacked in an extended state.

In the present embodiment, at least on the dorsal side A of the two diapers 1, the static friction coefficient μ11 between the back sheet of one diaper 1 and the front sheet of the other diaper 1 is 0.43 or less. The coefficient of static friction μ11 is preferably 0.25 to 0.43, more preferably 0.25 to 0.41, and even more preferably 0.25 to 0.38. The detailed measurement method of the static friction coefficient μ11 will be described later.

In order to realize the value of the static friction coefficient μ11, in the diaper 1, for example, friction is applied to a part or the entire surface of the skin facing surface AI of the dorsal side A and / or the non-skin facing surface AO of the dorsal side A. A reduction treatment and / or a surface roughness reduction treatment is performed.

In the diaper 1, as shown in FIG. 1, an oil agent 7 for reducing friction is applied to the entire surface of the non-skin facing surface AO of the dorsal side A (the entire region shown by the diagonal line in FIG. 1) as a friction reducing treatment. There is. Specifically, in the diaper 1A, the oil agent 7 is applied to the entire surface of the non-skin facing surface AO of the dorsal side A of the fourth sheet 62, which is the outermost layer sheet.

In the diaper 1, the portion 7d to which the oil agent 7 is applied is further subjected to a treatment for reducing the surface roughness. Specifically, in the diaper 1, the portion of the non-skin facing surface of the fourth sheet 62 to which the oil agent 7 is applied is processed by compression to reduce the surface roughness of the non-skin facing surface of the fourth sheet 62. It is decreasing.

Therefore, in the diaper 1, the friction and surface roughness of the portion 7d to which the oil agent 7 is applied is reduced with respect to the friction and surface roughness of the non-skin facing surface O of the ventral side B or the inseam C. There is. The portion of the diaper 1 to which the oil agent is applied is not limited to this, and may be applied to, for example, a portion of the non-skin facing surface AO of the inseam C that is close to the dorsal side A.

The material for forming the diaper 1 of the present embodiment will be described.
The first sheet 2, the second sheet 3, the side cuff 51 forming sheet, the third sheet 61 and the fourth sheet 62 are not particularly limited as long as they are usually used for absorbent articles such as disposable diapers. Can be used. For example, as the first sheet 2, a liquid-permeable non-woven fabric, a perforated film, a laminate thereof or the like can be used, and as the second sheet 3, a resin film or a laminate of a resin film and a non-woven fabric or the like can be used. Can be used. As the sheet for forming the lateral cuffs 51, an elastic film, a non-woven fabric, a woven fabric, or a laminated sheet thereof or the like can be used. As the third sheet 61 and the fourth sheet 62, a water-repellent non-woven fabric or the like can be used.

Here, the ratio of the compression work WCb of the front sheet (for example, the first sheet 2) to the compression work WCa of the back sheet (for example, the fourth sheet 62) (that is, WCb / WCa) is 2.0 to 12. It is preferably .0, more preferably 5.0 to 10.0, and even more preferably 6.5 to 8.5. The compression work amount WC is a value indicating the ease of compression of the sheet. Generally, the larger the compression work amount WC, the softer the sheet feels when it touches the wearer's skin, but the friction on the surface of the sheet tends to increase. By doing so, the friction between the front sheet (for example, the first sheet) and the back sheet (for example, the fourth sheet) is not impaired without impairing the texture of the front sheet (for example, the first sheet) that touches the wearer's skin. It can be reduced and the pullability of the diaper after use can be improved. The compression work amount WC can be measured using, for example, KES-FB3 (trade name) manufactured by Kato Tech Co., Ltd., which is a compression tester.

The absorbent core 4 can be used without particular limitation as long as it is usually used for absorbent articles such as disposable diapers. For example, as the absorbent core 4, a fiber aggregate of a fiber material such as pulp or a material in which a highly absorbent polymer is supported thereof is wrapped with a covering material such as tissue paper or a water-permeable non-woven fabric. Can be used.

The elastic member 52 for forming the lateral cuffs, the waist elastic member 63, and the leg elastic member 64 can be used without particular limitation as long as they are usually used for absorbent articles such as disposable diapers. For example, a stretchable material made of natural rubber, polyurethane, a polystyrene-polyisoprene copolymer, a polystyrene-polybutadiene copolymer, a polyethylene-α-olefin copolymer such as ethyl-ethylene acrylate, or the like can be used.

Examples of the components of the oil agent 7 applied to the non-skin facing surface AO of the dorsal side A include liquid paraffin, silicone oil, animal and vegetable oils (olive oil, jojoba oil, benivana oil, squalane, squalene, etc.), mono, di, and so on. Triglyceride, aliphatic ethers (myristyl-1,3-dimethylbutyl ether, palmityl-1,3-dimethylbityl ether, stearyl-1,3-dimethylbutyl ether, palmityl-1,3-methylpropyl ether and stearyl-1,3- Methylpropyl ether, etc.), isostearyl-cholesterol ester, etc. can be used, and silicone oil is particularly preferable from the viewpoint of reducing friction and causing less irritation to the skin. Of these, modified silicone oil containing an amino group is most preferable from the viewpoint of reducing friction.

As a coating method of the oil agent 7, known coating methods such as slot coating, die coating, bead coating, spiral coating, and gravure coating can be used. The oil agent can be applied as an oil agent or a coating liquid containing the oil agent. The coating amount (coating amount after drying) of the oil agent 7 is preferably about 1 to 50 g / m ² , particularly about 5 to 15 g / m ² , from the viewpoint of achieving both a friction reducing effect and a good touch.

The fastening tape 8 can be used without particular limitation as long as it is usually used for absorbent articles such as disposable diapers. For example, "Magic tape (registered trademark)" (manufactured by Kuraray Co., Ltd.) or the like can be used. Can be done. As the target tape 9, a loop material (female member) that can engage with the hook material of the fastening tape 8 can be used without particular limitation.

Next, the action and effect when the above-mentioned diaper 1 is used will be described.
FIG. 4 is a diagram for explaining a method of exchanging the diaper 1. When replacing the used diaper 1, the operator inserts the unfolded unused diaper 1 between the diaper 1 worn by the wearer H and the workbench T. Hereinafter, the diaper 1 worn by the wearer H is referred to as 1A, and the unused diaper 1 is referred to as 1B.

The operator pulls out the diaper 1A after removing the fastening tape 8 of the diaper 1A from the target tape 9. At this time, if the diaper 1A and the diaper 1B are not slippery, the diaper 1B may be pulled out together with the diaper 1A. In this case, the operator needs to reinsert the diaper 1B below the buttocks of the wearer H, which deteriorates the work efficiency. Further, if the diaper 1A and the diaper 1B are not slippery, the work of inserting the diaper 1B between the diaper 1A and the workbench T may not be smoothly performed. In the state of FIG. 4, the non-skin facing surface O of the dorsal side A of the diaper 1A and the skin facing surface I of the dorsal side A of the diaper 1B are pressed against each other with a particularly large force.

Therefore, in the present embodiment, the static friction coefficients μ11, μ12, and μ13 of the back surface sheet arranged on the non-skin facing surface O of the diaper 1 and the front surface sheet arranged on the skin facing surface I are preferably determined to be the diaper 1 Improve workability when replacing.

In the present embodiment, at least on the dorsal side A of the two diapers 1, the coefficient of static friction μ11 between the back sheet of one diaper 1A and the front sheet of the other diaper 1B is 0.43 or less. With the static friction coefficient μ11 in such a range, when the diaper 1A is slid in the longitudinal direction (Y direction) with respect to the diaper 1B, the diaper 1A can be pulled out smoothly, and the workability at the time of changing the diaper 1 is improved. can do. Further, the work of inserting the diaper 1B between the diaper 1A and the workbench T becomes easy.

In at least the back side A of the two diapers 1, the static friction coefficient μ12 in the width direction (X direction) between the back sheet of one diaper 1A and the front sheet of the other diaper 1B is the static friction in the longitudinal direction. It may be larger than the coefficient μ11 (μ11 <μ12). In this way, the diaper 1A and the diaper 1B are less likely to shift in the width direction (X direction). The static friction coefficient μ12 is preferably 0.05 or more larger than the static friction coefficient μ11, and more preferably 0.10 or more.

The static friction coefficient μ13 between the back sheet of one diaper 1A and the front surface sheet of the other diaper 1B in the ventral portion B of the two diapers 1 may be larger than the static friction coefficient μ11 (μ11 <μ13). In this way, when replacing the used diaper 1, the worker grabs the ventral side B of the diaper 1A and pulls it out, so that the worker's hand holding the diaper 1A does not slip easily, and when the diaper 1 is replaced. Workability can be improved. The static friction coefficient μ13 is preferably 0.02 or more larger than the static friction coefficient μ11, and more preferably 0.05 or more.

The static friction coefficients μ11, μ12 and μ13 can be measured by the following methods.
<Measurement method of static friction coefficient μ11>
FIG. 5 is a schematic view showing a method for measuring the static friction coefficient μ11 using a tensile tester. The measurement can be performed using an autograph AG-X (trade name) manufactured by Shimadzu Corporation, which is a tensile tester.

Specific measurement is performed as follows (1) to (5).
(1) Two absorbent articles (diapers 1a and diapers 1b in FIG. 5) having the same configuration are prepared as measurement samples. Next, one of the absorbent articles (diaper 1b) is attached to the measuring table on a smooth metal surface in an unfolded state so that the non-skin facing surface O is in contact with the measuring table. That is, the diaper 1b is fixed to the measuring table with the skin facing surface I of the diaper 1b facing upward.
(2) Next, the other absorbent article (diaper 1a) in the unfolded state is placed on the skin-facing surface I of the diaper 1b so as to be aligned with each other in a plan view. At this time, the skin-facing surface I of the back side A of the diaper 1b and the non-skin-facing surface O of the back side A of the diaper 1a are in contact with each other.

(3) Next, a columnar weight (diameter 45 mm) weighing 590 g on the skin-facing surface I of the dorsal side A of the diaper 1a and at the center position in the width direction and the longitudinal direction is attached to a double-sided tape. And fix it. The weight applies a pressure of 3.7 kPa to the diapers 1a and 1b, imitating the pressure exerted by the wearer's buttocks on the used diapers when changing the used diapers. For example, when the wearer is a newborn baby, an infant or an infant, a pressure of 2 kPa to 5 kPa is applied to the two diapers sandwiched between the wearer and the workbench as shown in FIG.
(4) Next, the diaper 1a is folded in half in the longitudinal direction so that the skin facing surface I is on the inside and the ventral side B of the diaper 1a is on the top, and the non-skin facing surface O of the folded portion is folded. A clip (manufactured by KOKUYO Co., Ltd., double clip CLI33 (trade name)) is sandwiched at the center position in the width direction of. One end of the polyethylene index thread is fixed to the load cell, and one end is passed through a pulley and connected to a clip attached to the diaper 1a.
(5) Next, the load cell is raised at a speed of 300 mm / min, the diaper 1a is pulled in the horizontal direction, the frictional force at the moment when the diaper 1a starts to move is set as the maximum static friction coefficient (Fμs), and the static friction coefficient (μ11) is set. It is measured by μ11 = Fμs (maximum static friction force {gf}) / Fn (vertical load due to weight {gf} + vertical load due to own weight of diaper 1a {gf}). The tension direction of the diaper 1a is the longitudinal direction of the diaper 1a and the diaper 1b.

<Measurement method of static friction coefficient μ12>
The static friction coefficient μ12 is set to the center position in the longitudinal direction of the diaper 1a in which the position where the clip is sandwiched is folded in half in the longitudinal direction in (4) of the measurement method of the static friction coefficient μ11, and in (5). The measurement is performed in the same manner as the static friction coefficient μ11 in the longitudinal direction, except that the tensile direction of the diaper 1a is the width direction of the diaper 1a and the diaper 1b.

<Measurement method of static friction coefficient μ13>
The static friction coefficient μ13 is the position where the weight is fixed on the skin-facing surface I of the ventral side B of the diaper 1a in the measurement method (3) of the static friction coefficient μ11 in the longitudinal direction, and the width direction and the longitudinal length thereof. When the diaper 1a is folded back in half in the longitudinal direction in the central position in the direction and in (4), the skin facing surface I is on the inside and the back side A of the diaper 1a is on the top. The measurement is performed in the same manner as the coefficient of static friction μ11 in the longitudinal direction except that the material is folded back.

(Examples and comparative examples)
Hereinafter, examples and comparative examples of the present invention will be described.
Using two disposable diapers (diapers 1a and diaper 1b) as measurement samples according to Examples, Comparative Example 1 and Comparative Example 2, measurement of static friction coefficients μ11, μ12 and μ13, insertability / withdrawal when changing diapers The properties were evaluated, and the compressive work WCb and WCa of the front sheet and the back sheet were measured. The static friction coefficients μ11, μ12, and μ13 are 5 according to the above measurement method so that the two disposable diapers (diapers 1a and diaper 1b) as measurement samples are in contact with each other so that the front sheet of the diaper 1b and the back sheet of the diaper 1a are in contact with each other. Measured times. The average values of the static friction coefficients μ11 and μ12 are shown in Table 1 below. Further, the difference between the static friction coefficients (μ13-μ11) was calculated from the average values of the static friction coefficients μ11 and μ13, and the results are shown in Table 1 below. The method of evaluating the insertability and pullability at the time of changing the diaper and the method of measuring the compression work amount WCb and WCa of the front sheet and the back sheet will be described later.

As the two disposable diapers (diapers 1a and diaper 1b) used as measurement samples according to the examples, 100 mg (12) of silicone, which is an oil for reducing friction, was applied to a specific region of the non-skin facing surface of the deployable disposable diaper. .5 g / m ² ) After application, a dried product was used. As the measurement sample according to the example, two deployable disposable diapers (weight 23 g) using the following as a front sheet, a back sheet, and an absorber were used. The other configuration of the measurement sample is the same as that of the absorbent article according to the embodiment shown in FIGS. 1 to 3. The surface sheet has a core-sheath structure in which the core component is polyethylene terephthalate (PET) and the sheath component is polyethylene (PE), and is composed of fibers having a fiber diameter of 16 μm, and has a basis weight produced by an air-through method. A 24 g / m ² non-woven fabric was used. For the back sheet, a non-woven fabric having a basis weight of 21 g / m ² produced by the spunbond method, which was mainly composed of polypropylene (PP) and had a fiber diameter of 14 μm, was used. As the absorber, a mixture of pulp and a highly absorbent polymer (basis weight 360 g / m ² ) was used.
As the silicone, KF-96-100CS (trade name) manufactured by Shin-Etsu Chemical Co., Ltd. was used. Silicone is 100 mm in the direction of having the back side from the center line bisected in the longitudinal direction and 2 mag in the width direction on the non-skin facing surface on which the back sheet of the outer packaging material of the unfolded unused disposable diaper is arranged. The coating was applied to a region (length x width: 100 mm x 80 mm) of 40 mm in the width direction from the center line to be divided.

The application of the silicone was carried out by the following procedure. First, silicone was applied to the entire surface of a PET film (Star OHP film (trade name), manufactured by Star Shoji Co., Ltd.) (length x width: 100 mm x 80 mm) using a brush. Next, the PET film was placed on the non-skin facing surface of the unfolded unused disposable diaper with the silicone-coated side facing down. Next, a 1 kg roller was reciprocated 5 times from the PET film to transfer the silicone applied to the PET film to the region on the non-skin facing surface of the disposable diaper. At this time, the value obtained by subtracting the weight of the PET film after the silicone transfer from the weight of the PET film immediately after the silicone was applied was defined as the amount of the silicone applied before drying. The amount of silicone applied after drying is 7.8 g / m ² .

As the two disposable diapers (diapers 1a and diaper 1b) used as measurement samples according to Comparative Example 2, only the back sheet of the deployable disposable diaper according to the above embodiment was changed. The back sheet has a core-sheath structure in which the core component is polyethylene terephthalate (PET) and the sheath component is polyethylene (PE), and is composed of fibers having a fiber diameter of 12 μm, and has a basis weight produced by an air-through method. A 24 g / m ² non-woven fabric was used.

<Evaluation of insertability / pullability when changing diapers>
Using the measurement samples (diapers 1a and diapers 1b) according to Example 1, Comparative Example 1 and Comparative Example 2, a panel of 5 people exchanged disposable diapers for infant models and exchanged disposable diapers. The burden on the operator (insertability and pull-out property) was evaluated. As the infant model, a model (weight 2.5 kg) from the thigh to the chest that imitated the average size of an infant wearing an S size disposable diaper was used. This evaluation will be described with reference to FIG. In this measurement, diapers 1a and 1b, which are measurement samples, were used so as to correspond to diapers 1A and diapers 1B in FIG. 4, respectively.

First, the infant model, which is the wearer H wearing the disposable diaper 1A, is placed on the table on which the towelette is laid in a supine position so that the non-skin facing surface O of the back side A of the disposable diaper 1A is in contact. To do. Next, the panel, which is the worker, places the dorsal part A of the unfolded disposable diaper 1B between the dorsal part A of the diaper 1A worn by the wearer H and the towelette along the longitudinal direction from the inseam side. And plug it in. In this insertion operation, the diaper 1B is inserted in the direction in which the skin-facing surface I of the back side A of the diaper 1B and the non-skin-facing surface O of the back side A of the diaper 1A are in contact with each other. Further, in this insertion operation, the diapers 1B are inserted until the positions of the diapers 1A and 1B in the plan view match (that is, until the ends of the dorsal side A side in the longitudinal direction of the diapers 1A and 1B match). Plug in. Subsequently, the panel, which is the operator, removes the fastening tape of the diaper 1A, then grasps the ventral side B of the diaper 1A, and pulls out the diaper 1A from under the buttocks of the infant model along the longitudinal direction.

The insertability of disposable diapers is "2" when the panel of 5 people feels that the insertability is very good (when inserting the diaper 1B, it can be inserted smoothly without getting caught in the diaper 1A). , "1" if you feel that the insertability is a little good, "0" if you feel that the insertability is neither, "-1" if you feel that the insertability is a little bad, the insertability is If you feel that it is not good (when you insert the diaper 1B, it gets caught in the diaper 1A and cannot be inserted smoothly), it is evaluated with a five-step numerical value of "-2", and the value is averaged. The results are shown in Table 1 below.

The pullability of disposable diapers is "2" when the panel of 5 people feels that the pullability is very good (when pulling out the diaper 1A, the diaper 1B does not shift) during the above pulling work, and the pullability is slightly. "1" if you feel it is good, "0" if you feel that the pullability is neither, "-1" if you feel that the pullability is not good, the pullability is not good (diaper 1A) If you feel that the diaper 1B is also pulled out when you pull out the diaper, evaluate it with a numerical value of "-2" in five stages, and the value is averaged. The results are shown in Table 1 below.

<Measurement method of compression work WCb and WCa of front sheet and back sheet>
From two disposable diapers (diapers 1a and diaper 1b) to be measurement samples according to Example 1, Comparative Example 1 and Comparative Example 2, the front surface sheet of the back side of the diaper 1b and the back surface of the back side of the diaper 1a. The sheet was peeled off using a cold spray. Next, each of the peeled sheets was allowed to stand for 12 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50% in a state where wrinkles were stretched on an acrylic plate.

Next, using each sheet adjusted in this way, the compression work amount WC was measured using KES-FB3 (trade name) manufactured by Kato Tech Co., Ltd., which is a compression tester. First, a 7 cm × 7 cm test piece was cut out from each sheet and attached to a test table. Next, the test piece was compressed between steel plates having a circular plane with an area of 2 cm ² . The compression rate was 20 μm / sec and the maximum compression load was 4.9 kPa. The recovery process was also measured at the same rate. The compression work amount WC was measured at three points for each test piece, and three times for each sheet. Here, the compression work of the back sheet of the diaper 1a is WCa, the compression work of the front sheet of the diaper 1b is WCb, and the average value of the measurement results of these nine points is shown in Table 1 below. In addition, the ratio of compression work (WCb / WCa) was calculated, and the results are shown in Table 1 below.

Static friction coefficient (μ11 and μ12) according to Examples, Comparative Example 1 and Comparative Example 2, difference in static friction coefficient (μ13-μ11), insertability when changing diapers, pullability when changing diapers, back surface of diaper 1a Table 1 shows the measurement results of the compression work amount WCa of the sheet, the compression work amount WCb and WCb / WCa of the surface sheet of the diaper 1b.

In the measurement sample according to the example, since the static friction coefficient μ11 is 0.43 or less, the evaluation result of the insertability / pull-out property at the time of changing the diaper is 1.0 as compared with the measurement sample according to Comparative Examples 1 and 2. It was good because it exceeded. From this, it can be seen that in the measurement sample according to Example 1, the operator was able to smoothly insert and pull out the absorbent article when changing the diaper, and was able to improve the workability when changing the absorbent article. .. Further, in the measurement sample according to the example, since the static friction coefficient μ12 is larger than the static friction coefficient μ11, it is considered that it is unlikely to shift in the width direction when the absorbent article is replaced. Further, in the measurement sample according to the example, since the oil for reducing friction is applied only to the dorsal side and a part of the inseam of the non-skin facing surface, the difference in static friction coefficient (μ13-μ11) is from 0. Is also big. Therefore, in the measurement sample according to the example, it is considered that the hand gripping the ventral side of the diaper is not slippery when the absorbent article is replaced. Further, in the measurement sample according to the example, since the ratio of the amount of compression work (WCb / WCa) is 2.0 to 12.0, the surface sheet and the surface sheet do not impair the texture of the surface sheet that comes into contact with the wearer's skin. Friction with the back sheet can be reduced.

The disposable diaper of the present invention is not limited to the disposable diaper 1 of the above-described embodiment, and can be appropriately changed.

1 ... Disposable diaper 2 ... 1st sheet 3 ... 2nd sheet 4 ... Absorbent core 5 ... Absorbent body 6 ... Outer packaging material 61 ... 3rd sheet 62 ... 4th sheet 63 ... Waist elastic member 64 ... Leg elastic member 7 ... Oil 8 ... Fastening tape 9 ... Target tape

Claims (5)

It is provided with a front surface sheet arranged on the skin facing surface, a back surface sheet arranged on the non-skin facing surface, and an absorbent core arranged between these two sheets, and has a longitudinal direction corresponding to the front-back direction of the wearer and the longitudinal direction. In an absorbent article having a width direction orthogonal to and having a ventral portion arranged on the ventral side of the wearer, a dorsal portion arranged on the dorsal side of the wearer, and a crotch located between them. There,
At least on the dorsal side of the two absorbent articles, the static friction coefficient μ11 in the longitudinal direction between the back sheet of one absorbent article and the front surface sheet of the other absorbent article is 0. Absorbent article of .43 or less. At least on the dorsal side of the two absorbent articles, the static friction coefficient μ12 in the width direction between the back sheet of one absorbent article and the front sheet of the other absorbent article is in the longitudinal direction. The absorbent article according to claim 1, which has a coefficient of static friction greater than μ11. The coefficient of static friction μ13 between the skin-facing surface of one absorbent article and the non-skin-facing surface of the other absorbent article on the ventral side of the two absorbent articles.
The first or second claim, wherein the coefficient of static friction between the one absorbent article and the surface sheet of the other absorbent article in the crotch portion or the dorsal portion of the two absorbent articles is larger than the static friction coefficient μ11. Absorbent article. The absorbent article according to any one of claims 1 to 3, wherein a part or the entire surface of the back surface sheet on the back side portion has an oil agent for reducing friction. The absorbent article includes a first sheet arranged on the skin-facing surface side, a second sheet arranged on the non-skin-facing surface side, and an absorbent body having an absorbent core arranged between the two sheets. , With an outer packaging material having a third sheet and a fourth sheet,
The outer packaging material is fixed by arranging the third sheet on the non-skin facing surface of the absorbent body.
The absorbent article according to claim 4, wherein the oil agent is applied to the fourth sheet.

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