JP7117957B2 - absorbent article - Google Patents

Description

The present invention relates to absorbent articles used for absorbing bodily fluids.

Absorbent articles such as disposable diapers and sanitary napkins typically have a topsheet arranged to be in contact with the wearer's skin and a backside arranged farther from the wearer's skin than the topsheet. It is composed of a sheet and an absorbent body interposed between the two sheets, and the absorbent body absorbs and retains body fluids such as urine, feces, and menstrual blood excreted from the crotch region. In the absorbent article having such a structure, the topsheet is required to be excellent in liquid absorption performance and dry feeling that the user feels after excretion, because the topsheet may come into contact with the wearer's skin when worn. In addition, when the absorbent article is worn, liquid once absorbed by the absorbent body may migrate to the topsheet side due to body pressure during wearing, or so-called liquid return may occur. It is also required to suppress permeation of the liquid that has migrated from the absorbent body side due to liquid return to the wearer's skin side.

In addition to the topsheet, the absorbent article usually includes a member arranged to be in contact with the wearer's skin (hereinafter also referred to as "skin-contacting sheet") other than the topsheet. Other skin-contacting sheets are also exposed to liquids such as the wearer's perspiration. For example, as the skin-contacting sheet, there is an absorbent article including a sweat absorbing sheet. Since the sweat-absorbing sheet may come into contact with the wearer's skin when worn, it is required to absorb the wearer's sweat and keep the wearer's skin dry at all times. It is required to prevent redeposition to human skin. In an absorbent article having such a configuration, the sweat-absorbing sheet may be arranged at a position (for example, around the waist) that does not overlap with the absorber, unlike the topsheet that is arranged at a position overlapping with the absorber. The sweat-absorbent sheet itself is required to quickly absorb sweat adhering to the wearer's skin and quickly evaporate the absorbed sweat. As described above, the sweat-absorbing sheet is required to quickly evaporate the absorbed liquid without leaving any residue, that is, it is required to have little remaining liquid. On the other hand, the sweat-absorbent sheet has a smaller amount of body fluid to be absorbed than the top sheet due to its arrangement position, etc., and the body fluid once absorbed by the sweat-absorbent sheet is not returned to the wearer's skin side. Since the liquid evaporates in many cases, the problem of liquid return is often less apparent than in the case of the top sheet.

Patent Document 1 discloses a laminated nonwoven fabric suitable for a surface sheet or the like, which has embossed portions in which long fibers are bonded together by thermocompression bonding, and the hydrophilicity of the embossed portions is lower than the hydrophilicity of the non-embossed portions. Have been described. The laminated nonwoven fabric described in Patent Document 1 is produced by hot embossing a web of long fibers coated with a specific fiber treatment agent to form the embossed portions. Since the hydrophilicity of the attached fiber surface is reduced by heat treatment, the embossed portion is less hydrophilic than the non-embossed portion which is not subjected to heat embossing.

Patent Literature 2 describes an absorbent article in which the skin-facing surface of the waist area is formed of a sweat-absorbing sheet in which an elastic member is arranged between two fiber sheets. In one embodiment of the sweat-absorbent sheet, the fiber sheet positioned closer to the wearer's body has a lower degree of hydrophilicity than the fiber sheet positioned farther from the wearer's body (claim of Patent Document 2). Item 4, etc.). Further, in [0051] of Patent Document 2, of the two fiber sheets constituting the sweat-absorbing sheet, the fiber sheet located on the side relatively far from the wearer's body is a spunbond-meltblown (SM) nonwoven fabric. and spunbond-meltblown-spunbond (SMS) nonwovens can be used.

Patent Document 3 discloses an absorbent article comprising a liquid-permeable topsheet and an absorbent body, wherein the topsheet is given surface embossing from the surface side of the topsheet, and the absorbent body is subjected to the surface embossing. It is described that core embossing is provided from the surface side of the absorbent body to a region that does not overlap with the. [0033] of Patent Document 3 describes that a laminated nonwoven fabric obtained by a spunbond method, a meltblown method, or the like can be used as the surface sheet. According to Patent Document 3, by combining surface embossing and core embossing that directly contact the skin, the problem of the embossing directly coming into contact with the skin is reduced while the core embossing maintains the effect of preventing side leakage of bodily fluids. , is said to improve wearing comfort. Patent Document 3 does not describe the degree of hydrophilicity of each layer of the laminated nonwoven fabric used as the surface sheet.

JP 2015-132038 A JP 2016-112167 A JP 2013-248309 A

As mentioned above, absorbent articles use multiple types of skin-contacting sheets, such as topsheets and sweat-absorbing sheets, and these multiple types of skin-contacting sheets have a common feature of excellent liquid absorption performance. However, depending on the position of the skin-contacting sheet, the functions for enhancing the surface dryness may differ from each other, for example, the surface sheet has a function of suppressing liquid return, and the sweat-absorbent sheet has a function of suppressing liquid residue. . Therefore, in order to obtain a high-performance absorbent article with excellent liquid absorption performance and surface dry feeling, it is necessary to determine the type and required functions of the skin-contacting sheet contained in the absorbent article, and improve the performance of the skin-contacting sheet. It is important to plan individually.

Conventional absorbent articles have room for improvement in terms of the performance of skin-contacting sheets such as topsheets and sweat-absorbing sheets. Accordingly, an object of the present invention is to provide an absorbent article in which the skin-contacting sheet has excellent liquid absorption performance.

The present invention comprises a skin-contacting sheet arranged so as to be in contact with the wearer's skin when worn, the skin-contacting sheet having a laminated structure of a plurality of fiber layers, and the plurality of fiber layers fused together. An absorbent article including a laminated nonwoven fabric having a fused part that is bonded and integrated, wherein the fused part is formed on each of a first surface that is one surface and a second surface that is the other surface of the laminated nonwoven fabric. There are a fused portion and a non-fused portion where the plurality of fiber layers are not fused to each other, and the non-fused portion on the first surface is larger than the non-fused portion on the second surface. on the first surface, the non-fused portion has a lower hydrophilicity than the fused portion, and a square unit area of 10 mm square in plan view including the fused portion is defined as the When virtually provided on the first surface, the first surface has a high hydrophilicity region that is a unit region with a relatively high surface hydrophilicity and a low hydrophilicity that is a unit region with a relatively low surface hydrophilicity. region.

In addition, the present invention includes a skin-contacting sheet disposed so as to be in contact with the wearer's skin when worn, the skin-contacting sheet having a laminated structure of a plurality of fiber layers, and the plurality of fiber layers integrated together. A method for producing an absorbent article comprising a laminated nonwoven fabric having a fused part that is physically fused, comprising: a step for producing the laminated nonwoven fabric; and an absorbent article using the laminated nonwoven fabric produced by the production step In the manufacturing process of the laminated nonwoven fabric, a plurality of fiber webs are laminated to obtain a laminated body, and the laminated body is partially compressed in the thickness direction by compression processing while heating, A fused portion forming step of forming the fused portion in the compressed portion of the laminate, wherein in the fused portion forming step, a partial area and another partial area of the laminate in plan view and performing the compression processing on the laminate so that at least one of the pressure applied to the compressed portion, the area of the compressed portion, and the number of compressed portions per unit area is different. The method.

ADVANTAGE OF THE INVENTION According to this invention, the absorbent article which is excellent in the liquid absorption performance of a skin contact sheet is provided.

FIG. 1 is a perspective view schematically showing an underpants-type disposable diaper that is one embodiment of the absorbent article of the present invention. FIG. 2 is a developed plan view schematically showing the skin-facing surface side (inner surface side) of the diaper shown in FIG. 1 in an unfolded and stretched state. FIG. 3 is a cross-sectional view schematically showing a section taken along line II in FIG. 2 (a section along the horizontal direction). FIG. 4 is a cross-sectional view schematically showing the II-II line cross section (cross section along the longitudinal direction) of FIG. 2, and one longitudinal end portion of the diaper shown in FIG. ) is an enlarged schematic longitudinal sectional view. FIG. 5 is a schematic perspective view of the first surface side (skin-facing surface side) of one embodiment of the laminated nonwoven fabric that constitutes the skin-contacting sheet of the diaper shown in FIG. 6 is a schematic plan view of part of the first surface (skin-facing surface) of the laminated nonwoven fabric shown in FIG. 5. FIG. FIG. 7 is a schematic cross-sectional view taken along the line III-III in FIG. 6 (a cross section along the thickness direction of the laminated nonwoven fabric). FIG. 8 is a schematic plan view of one embodiment of each of the high hydrophilicity region and the low hydrophilicity region on the first surface of the laminated nonwoven fabric according to the present invention. FIG. 9 is a schematic plan view of another embodiment of each of the high hydrophilicity region and the low hydrophilicity region on the first surface of the laminated nonwoven fabric according to the present invention. FIG. 10 is a schematic configuration diagram of one embodiment of a manufacturing apparatus that can be used to carry out the manufacturing process of the laminated nonwoven fabric. FIG. 11 is a schematic configuration diagram of another embodiment of a manufacturing apparatus that can be used for carrying out the manufacturing process of the laminated nonwoven fabric. FIGS. 12(a) to 12(c) are cross-sectional views of main parts of the compression means provided in the manufacturing apparatus shown in FIGS. 10 and 11, respectively. It is a sectional view showing typically a section along a height direction of the convex part.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the absorbent article of the present invention will be described based on its preferred embodiments with reference to the drawings. 1 to 4 show an underpants-type disposable diaper 1 that is one embodiment of the absorbent article of the present invention. As shown in FIGS. 1 and 2, the diaper 1 has a longitudinal direction X corresponding to the front-rear direction of the wearer, that is, a direction extending from the abdomen to the back through the crotch, and a lateral direction Y orthogonal thereto. , and a ventral portion F and a dorsal portion R disposed on the dorsal side of the wearer when worn, and a crotch portion M located between the ventral portion F and the dorsal portion R and The ventral portion F is positioned forward of the crotch portion M in the longitudinal direction X, and the back portion R is positioned rearward of the crotch portion M in the longitudinal direction X. (around the waist). The crotch part M includes an excretory part facing part (not shown) that is disposed between the wearer's crotch when the diaper 1 is worn and faces the wearer's excretory part such as the penis.

The diaper 1 includes an absorbent main body 2 including a liquid-retaining absorbent 23 (absorbent core 24) in the central portion in the lateral direction Y, and the non-skin-facing side of the absorbent main body 2, that is, the absorbent main body. 2, and both side edges along the longitudinal direction X of the exterior body 3 in the ventral part F and the dorsal part R are bonded with an adhesive or heat. are joined to each other by known joining means such as seals, ultrasonic seals, etc., and as shown in FIG. A pair of leg openings LH, LH are formed through which the lower legs are passed.

As used herein, the term “skin-facing surface” refers to the surface of the absorbent article or its constituent members (for example, the sweat-absorbing sheet 4 described later) that faces the wearer's skin when the absorbent article is worn, that is, the surface facing the wearer's skin when the absorbent article is worn. The side close to the skin of the wearer, and the "non-skin facing surface" is the side of the absorbent article or its constituent members that faces away from the skin when the absorbent article is worn. The side farthest from the skin. It should be noted that the term "when worn" as used herein means a state in which the absorbent article is maintained in a normal and appropriate wearing position, that is, in a correct wearing position of the absorbent article.

The absorbent main body 2 has a rectangular shape in plan view in the unfolded and stretched state of the diaper 1 as shown in FIG. is aligned with the longitudinal direction X of the diaper 1 in the unfolded and stretched state, arranged in the center of the outer body 3 in the lateral direction Y, and joined to the outer body 3 with an adhesive. The "unfolded and stretched state" of the diaper 1 means that the diaper 1 is cut off at the side seal portion S to be in the unfolded state, and the elastic members of each part of the diaper 1 in the unfolded state are stretched to the design size (the influence of the elastic member is completely removed). It means the state in which it is expanded until it becomes the same dimension as when it is expanded in a flat state in the excluded state).

As shown in FIG. 3, the absorbent body 2 comprises a liquid-permeable top sheet 21 forming a skin-facing surface and a liquid-impermeable, liquid-impermeable or water-repellent back sheet 22 forming a non-skin facing surface. , and a liquid-retaining absorber 23 interposed between the sheets 21 and 22, which are integrated by a known bonding means such as an adhesive. As the top sheet 21 and the back sheet 22, various types of materials conventionally used for this type of absorbent article can be used without particular limitation. For example, various non-woven fabrics, perforated films, etc. can be used as the top sheet 21, and resin films, laminates of resin films and non-woven fabrics, etc. can be used as the back sheet 22. FIG.

The absorbent body 23 includes a liquid-retaining absorbent core 24 mainly made of an absorbent material, and a core wrap sheet 25 covering the outer surface of the absorbent core 24, that is, the skin-facing surface and the non-skin-facing surface. It is The absorbent core 24 and the core wrap sheet 25 may be joined by a known joining means such as a hot-melt adhesive. The absorbent core 24 has a rectangular shape elongated in the vertical direction X in plan view as shown in FIG. In this embodiment, the absorbent core 24 extends in the longitudinal direction X from the ventral portion F to the dorsal portion R. As shown in FIG. As the absorbent material that forms the main body of the absorbent core 24, any material that is used as an absorbent body material in this type of absorbent article can be used without particular limitation. , water-absorbing polymers, and the like. As a typical form of the absorbent core 24, a fiber aggregate of hydrophilic fibers such as wood pulp, or a fiber aggregate holding particulate water-absorbent polymer can be exemplified. As the core wrap sheet 25, for example, liquid-permeable sheets such as paper, various nonwoven fabrics, and perforated films can be used.

As shown in FIGS. 2 and 3, both sides along the longitudinal direction X of the skin-facing surface of the absorbent body 2 are provided with liquid-resistant or water-repellent and air-permeable leak-proof cuff-forming sheets 27. A pair of leakproof cuffs 26, 26 are also provided. One or more thread-like elastic members 28 for forming a leak-preventing cuff are arranged in the longitudinal direction X in a stretched state near the free end of each leak-preventing cuff 26 . The leakage-preventing cuff 26 stands up at least at the crotch portion M by contracting the elastic member 28 arranged in a stretched state when the diaper 1 is put on, thereby preventing excreted fluid such as urine from flowing outward in the lateral direction Y. prevent

The outer body 3 forms the outer shape of the diaper 1 in the unfolded and stretched state as shown in FIG. It forms the outline of each dorsal part R. As shown in FIG. 2, the exterior body 3 has a rectangular shape in which the ventral part F and the dorsal part R are longer in the lateral direction Y than the longitudinal direction X, and the ventral part F and the dorsal part In the crotch portion M located between R, both side edges along the longitudinal direction X of the exterior body 3, that is, a pair of leg edges LS, LS are curved in a convex arc shape toward the center in the lateral direction Y. In a plan view as shown in FIG. 2, the center region in the vertical direction X is constricted inward in the horizontal direction Y to form an hourglass shape.

As shown in FIGS. 3 and 4, the outer body 3 includes an outer layer sheet 31 that forms the outer surface of the diaper 1 in the worn state, that is, the non-skin facing surface, and an inner layer sheet 32 that is arranged to face the skin facing surface of the outer layer sheet 31. It is configured including a laminate of When the diaper 1 is worn, the outer layer sheet 31 is located farther from the wearer's body and forms the non-skin facing surface (outer surface) of the diaper 1, and the inner layer sheet 32 is located closer to the wearer's body. Then, the skin facing surface (inner surface) of the diaper 1 is formed. The outer layer sheet 31 and the inner layer sheet 32 are joined to each other at a predetermined site through a joining means such as an adhesive.

In this embodiment, as shown in FIGS. 2 and 4, the outer layer sheet 31 extends from the longitudinal ends of the inner layer sheet 32 to the ventral side F and the dorsal side R, and the inner layer sheet 32 faces the skin. It has a folded portion 31E that is folded back to the side, and the folded portion 31E covers the end portion of the absorbent body 2 in the longitudinal direction X. As shown in FIG. Although FIG. 4 shows an enlarged longitudinal end of the dorsal portion R and does not show an enlarged view of the ventral portion F, the ventral portion F is configured in the same manner as the dorsal portion R. Unless otherwise specified, the description of the dorsal portion R applies to the ventral portion F as appropriate.

The sheets 31 and 32 forming the exterior body 3 may be sheets of the same type or different types of sheets, and examples of the latter include forms having different stretchability. Specifically, for example, a stretchable sheet having stretchability in the lateral direction Y can be used as the outer layer sheet 31 , and a non-stretchable sheet having no stretchability can be used as the inner layer sheet 32 . Further, for example, the stretchability of the outer layer sheet 31 may be partially different. and the portion of the outer layer sheet 31 located at the crotch portion M is made of a non-stretchable sheet having no stretchability. Examples of the stretchable sheet that can be used as the exterior body 3 include a stretchable sheet in which stretchable fiber layers are integrated on both sides or one side of an elastic fiber layer. Methods of integration include, for example, a method of laminating and hydroentangling the two, a method of entangling fibers by air-through or the like, and a method of bonding by heat embossing, an adhesive, ultrasonic waves, or the like. Non-stretchable sheets that can be used as the exterior body 3 include, for example, nonwoven fabrics produced by various methods, and specific examples include spunbond nonwoven fabrics, air-through nonwoven fabrics, and needle-punched nonwoven fabrics.

As shown in FIGS. 1, 2 and 4, a plurality of thread-like or band-like waist elastic members 33 are arranged in the lateral direction Y in a stretched state in the ventral portion F and the dorsal portion R, respectively. The waist elastic members 33 of the book are intermittently arranged in the vertical direction X at predetermined intervals. Since the waist elastic member 33 is arranged in such a manner that its elastic stretchability is exhibited, the opening edge of the waist opening WH has an annular waist that is substantially continuous over the entire circumference. Gathers are formed. In addition, one or a plurality of thread-like or belt-like leg elastic members 34 for forming leg gathers are arranged in a stretched state at the leg edge LS forming the opening edge of each of the pair of leg openings LH, LH. As a result, substantially continuous annular leg gathers are formed at the opening edges of the pair of leg openings LH, LH. These elastic members 33 and 34 are sandwiched and fixed between the outer layer sheet 31 and the inner layer sheet 32 that constitute the exterior body 3 by a bonding means such as an adhesive.

The diaper 1 has waist flaps WF arranged outward in the longitudinal direction X from the longitudinal ends 24 a of the absorbent core 24 on at least one of the abdominal part F and the back part R. In this embodiment, as shown in FIGS. 1 and 2, waist flaps WF are arranged on both the ventral side F and the dorsal side R. As shown in FIGS. The waist flap WF is a portion of the diaper 1 located outside in the longitudinal direction X of an imaginary straight line VL extending parallel to the lateral direction Y through the longitudinal ends 24a of the absorbent core 24. It is the end portion in the direction X and the portion where the absorbent core 24 (absorbent material) is not arranged. The waist flap WF corresponds to the circumference of the wearer's waist when the diaper 1 is worn.

As shown in FIG. 4, the waist flap WF is mainly composed of the exterior body 3 (the outer layer sheet 31 and the inner layer sheet 32). The waist flap WF has a folded portion 31E of the outer layer sheet 31, and the folded portion 31E is the member closest to the wearer's skin of the diaper 1 in the exterior body 3 of the waist flap WF. As shown in FIG. 2, the folded portion 31E has a shape that is elongated in one direction in a plan view, specifically a rectangular shape, and the longitudinal direction thereof is aligned with the lateral direction Y, and the ventral portion F and the dorsal portion are formed. It is distributed over the full length of each horizontal direction Y of R.

At least one of the waist flap WF of the ventral portion F and the waist flap WF of the back portion R, preferably the latter, and more preferably both, is provided with a sweat absorbing function. More specifically, as shown in FIGS. 1, 2 and 4, at least a portion of the waist flap WF on the side facing the skin is formed of a sweat absorbing sheet 4 having a sweat absorbing function. The sweat-absorbent sheet 4 has a shape elongated in one direction, specifically a rectangular shape, in plan view as shown in FIG. are distributed. In the illustrated example, the sweat-absorbent sheet 4, which is separate from the outer layer sheet 31, is adhered to the skin-facing side of the outer layer sheet 31 at the folded portion 31E, which is closest to the wearer's skin. (The folded portion 31E) itself does not have a sweat absorbing function. However, in the absorbent article of the present invention, the outer layer sheet 31 itself at the folded portion 31E may be composed of the sweat absorbent sheet 4 .

In this embodiment, the sweat absorbent sheet 4 is bonded to the skin-facing surface of the folded portion 31E of the outer layer sheet 31 of the waist flap WF by a known bonding means such as adhesive, heat sealing, or ultrasonic sealing. Therefore, the waist flap WF has the sweat absorbing sheet 4, the folded portion 31E, the inner layer sheet 32, and the outer layer sheet 31 in order from the wearer's skin of the diaper 1. As shown in FIG. In addition, the waist flap WF is stretchable in the lateral direction Y due to having the waist elastic member 33 fixed in the lateral direction Y stretched state between the outer layer sheet 31 and the inner layer sheet 32. have.

In this embodiment, at least the surface of the folded portion 31E of the outer layer sheet 31 to which the sweat absorbent sheet 4 is fixed is hydrophobic, and is typically made of a nonwoven fabric containing hydrophobic fibers. As the nonwoven fabric constituting the folded portion 31E, nonwoven fabrics produced by various manufacturing methods that can be used as a constituent member of this type of absorbent article can be used without particular limitation, and nonwoven fabrics mainly composed of short fibers (short fiber nonwoven fabrics) may also be used. Alternatively, a nonwoven fabric mainly composed of long fibers (long fiber nonwoven fabric) may be used. The folded portion 31E may be, for example, a short-fiber nonwoven fabric such as an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlaced nonwoven fabric, a needle-punched nonwoven fabric, or a chemical-bonded nonwoven fabric, or may be a long-fiber nonwoven fabric such as a spunbond nonwoven fabric or a meltblown nonwoven fabric.

The diaper 1 includes a skin-contacting sheet arranged so as to be in contact with the wearer's skin when worn. The skin-contacting sheet is a sheet that forms the skin-facing surface (inner surface) of the diaper 1, and the skin-facing surface side (inner surface side) of the diaper 1 as shown in FIG. It is a sheet that can be viewed with In this embodiment, the skin-contacting sheets are the sweat absorbing sheet 4, the surface sheet 21, the leak-proof cuff forming sheet 27, and the inner layer sheet 32. As shown in FIG.

In the absorbent article of the present invention, the skin-contacting sheet includes a laminated nonwoven fabric, and the laminated nonwoven fabric has a laminated structure of a plurality of fiber layers, and the plurality of fiber layers are fused together. It has a fused portion that is bonded and integrated. When the absorbent article includes a plurality of the skin-contacting sheets, at least one of the plurality of skin-contacting sheets may be the laminated nonwoven fabric. All may be said laminated nonwoven fabrics. The skin-contacting sheet may include only the laminated nonwoven fabric, or may include other sheets. In the latter case, it is preferable that another sheet is arranged on the non-skin facing side of the laminated nonwoven fabric, that is, the laminated nonwoven fabric forms the skin facing side of the skin contacting sheet.

5 to 7 show a laminated nonwoven fabric 10, which is one embodiment of the laminated nonwoven fabric. In the diaper 1, the skin-contacting sheets are the sweat-absorbing sheet 4, the top sheet 21, the leak-proof cuff-forming sheet 27, and the inner layer sheet 32, so at least one of these sheets contains the laminated nonwoven fabric 10. be done. The laminated nonwoven fabric 10 has a laminated structure of a plurality of fiber layers 11 and 12, and has a first surface 10a as one surface and a second surface 10b as the other surface. In this embodiment, the laminated nonwoven fabric 10 has a two-layer structure of the fiber layers 11 and 12 , the first surface 10 a is formed from the fiber layer 11 and the second surface 10 b is formed from the fiber layer 12 . In the figure, reference numeral 11F indicates constituent fibers of the fiber layer 11, and reference numeral 12F indicates constituent fibers of the fiber layer 12. FIG. The plurality of fiber layers 11 and 12 are integrally fused at the fused portion 13 . The fused portion 13 is a portion where the plurality of fiber layers 11 and 12 forming the laminated structure of the laminated nonwoven fabric 10 are fused and integrated with each other. It is continuous in the thickness direction Z of the laminated nonwoven fabric 10 across the surface 10a and the second surface 10b. As will be described later, the fusing part 13 applies a melting promoting means (for example, heat, ultra It is formed by subjecting the laminate to compression processing accompanied by sound waves and heating while partially compressing the laminate in the thickness direction.

As shown in FIGS. 5 to 7, the first surface 10a and the second surface 10b of the laminated nonwoven fabric 10 have fused portions 13 and non-fused portions 14, respectively. The non-fused portion 14 is a portion where the plurality of fiber layers 11 and 12 constituting the laminated structure of the laminated nonwoven fabric 10 are not fused to each other. A portion other than 13 is a non-fused portion 14 .

In the present embodiment, as shown in FIGS. 5 and 6, a plurality of fused portions 13 are intermittently arranged on the first surface 10a. They are arranged in a zigzag manner, and each fused portion 13 is surrounded by a non-fused portion 14 . The pattern (planar view shape and arrangement) of the fused portion 13 is not limited to the illustrated form. For example, the planar view shape of the fused portion 13 may be an elliptical shape, a triangular shape, a polygonal shape having a quadrilateral shape or more, an irregular shape, a linear shape, a curved shape, or the like. Alternatively, for example, a lattice-like pattern in which a plurality of continuous linear fused portions 13 are arranged so as to intersect with each other may be used. As shown in FIG. 7, since the fused portions 13 are continuous in the thickness direction Z of the laminated nonwoven fabric 10, the pattern of the fused portions 13 is generally substantially the same on the first surface 10a and the second surface 10b. essentially the same. Therefore, in the present embodiment, a plurality of fused portions 13 are arranged in a staggered manner on the second surface 10b as well as on the first surface 10a, and each fused portion 13 is surrounded by a non-fused portion 14. there is

In the laminated nonwoven fabric 10, the non-fused portion 14 on the first surface 10a has a lower degree of hydrophilicity than the non-fused portion 14 on the second surface 10b. The non-fused portion 14 is an unprocessed portion of the laminated nonwoven fabric 10 that has not been subjected to compression processing, and the hydrophilicity originally possessed by the plurality of fiber layers 11 and 12 constituting the laminated nonwoven fabric 10 is substantially maintained. This is the part where In the present invention, the "contact angle of constituent fibers with water" is used as an index of hydrophilicity, and the smaller the contact angle, the higher the hydrophilicity of the surface of the laminated nonwoven fabric containing the constituent fibers (hydrophobicity is lower), and the larger the contact angle, the lower the hydrophilicity (the higher the hydrophobicity) of the surface of the laminated nonwoven fabric containing the constituent fibers. Therefore, in the laminated nonwoven fabric 10, as described above, the relationship of "hydrophilicity of the non-fused portion 14 of the first surface 10a<hydrophilicity of the non-fused portion 14 of the second surface 10b" is established. This means that the magnitude relationship of contact angle of non-fused portion 14 of first surface 10a>contact angle of non-fused portion 14 of second surface 10b is established. In this embodiment, the first surface 10a is formed from the fiber layer 11, and the second surface 10b is formed from the fiber layer 12. Therefore, "hydrophilicity of fiber layer 11 (constituent fiber 11F) < fiber layer 12 (constituent fiber 12F)". Hydrophilicity is measured by the following method.

<Method for measuring hydrophilicity>
A fiber is taken out from the surface (first surface 10a, second surface 10b) of the fiber layer to be measured, and the contact angle of water with respect to the fiber is measured. When taking out the fibers, scissors and tweezers are used, and the parts of the laminated nonwoven fabric to be measured where the fibers are taken out are the outermost surfaces of the unfused portion 14 on the first surface 10a and the unfused portion 14 on the second surface 10b. (outermost surface). As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Deionized water is used for contact angle measurements. The amount of liquid ejected from an ink-jet type water droplet ejector (a pulse injector CTC-25 with an ejector hole diameter of 25 μm, manufactured by Cluster Technology) is set to 15 picoliters, and water droplets are dropped just above the fibers. The state of dripping is recorded on a high-speed recording device connected to a camera placed horizontally. From the viewpoint of image analysis later, the recorder is preferably a personal computer with a built-in high-speed capture device. In this measurement, an image is recorded every 17 msec. In the recorded image, the first image of water droplets landing on the fiber is captured by the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2 method, image processing algorithm is non-reflective, the image processing image mode is frame, the threshold level is 200, and no curvature correction is performed. angle. The fiber taken out from the object to be measured is cut into a fiber length of 1 mm, and the fiber is placed on a sample stand of a contact angle meter and maintained horizontally. Two different contact angles are measured for each fiber. N = 5 contact angles are measured to the first decimal place, and the average value (rounded to the second decimal place) of a total of 10 measured values is defined as the contact angle of the fiber with water. The measurement environment is a room temperature of 22±2° C. and a humidity of 65±2% RH. A smaller contact angle value means a higher hydrophilicity.

In addition, when a constituent member including a measurement target (for example, a skin contact sheet) is collected from an absorbent article, the constituent member that is the object to be collected is attached to another constituent member via a joining means such as an adhesive or fusion. If it is joined, it is necessary to reduce the joining force of the joining means before collecting the object to be collected. In that case, as a method for reducing the bonding strength, there is a method of cooling a bonding means such as an adhesive using a commercially available cooling means such as a cold spray. After cooling the joining means to reduce the joining force, the constituent member to be collected is carefully peeled off from the other constituent members and collected. Such a method of collecting an object to be measured from an absorbent article can be applied to various measurements including the contact angle measurement described above. In addition to the above-mentioned "cooling of the joining means", methods for reducing the joining force of the joining means include, for example, applying a solvent and blowing hot air with a dryer. If a hydrophilizing agent is applied to the constituent member, the hydrophilizing agent may deteriorate or disappear. It is desirable not to adopt it from the viewpoint of minimizing the effect on the agent.

The skin-facing surface of the skin-contacting sheet (for example, the sweat-absorbing sheet 4) may be the first surface 10a or the second surface 10b of the laminated nonwoven fabric 10, but the dry feeling after liquid absorption is improved. From this point of view, it is preferable to use the first surface 10a, which has a relatively low hydrophilicity of the non-fused portion 14, that is, the first surface 10a which has a naturally low hydrophilicity, as the skin-facing surface of the skin-contacting sheet.

In the first surface 10 a of the laminated nonwoven fabric 10 , the non-fused portion 14 has a lower degree of hydrophilicity than the fused portion 13 . That is, on the first surface 10a, the contact angle measured by the above method has a magnitude relationship of "the contact angle of the non-fused portion 14>the contact angle of the fused portion 13".

As described above, the fused portion 13 is a portion where the plurality of fiber layers 11 and 12 constituting the laminated structure of the laminated nonwoven fabric 10 are fused and integrated with each other. , the hydrophilicity (contact angle of the constituent fibers) of the fused portion 13 is the hydrophilicity (contact angle of the constituent fibers 11F, 12F) of each of the plurality of fiber layers 11 and 12 integrated at the fused portion 13. average or close to it. The fused portion 13 is a portion where the constituent fibers 11F and 12F are fused together, and can be considered as a non-uniform surface according to the Cassie-Baxter formula. Since the non-uniform surface shows intermediate wettability of each component (cos θ=f ₁ cos θ ₁ +f ₂ cos θ ₂ (f ₁ +f ₂ =1)), applying this idea, the hydrophilicity of the fused portion 13 The degree is the average value of each fiber layer of the plurality of fiber layers 11 and 12 or something close to it. In the present embodiment, as described above, since the magnitude relationship of "hydrophilicity of fiber layer 11 (constituent fibers 11F)<hydrophilicity of fiber layer 12 (constituent fibers 12F)" is established, On the first surface 10a, the non-fused portion 14, which is not subjected to compression processing such as heat embossing for forming the fused portion 13, maintains the original hydrophilicity of the fiber layer 11 (constituent fibers 11F). . On the other hand, in the fused portion 13, the fiber layer 11 (component fiber 11F) having relatively low hydrophilicity and the fiber layer 12 (component fiber 12F) having relatively high hydrophilicity are melted by heat accompanying compression processing. Therefore, the hydrophilicity is improved (the contact angle measured by the above method is decreased) compared to before compression processing. Therefore, on the first surface 10a of the laminated nonwoven fabric 10, as described above, the magnitude relationship of "the contact angle of the non-fused portion 14>the contact angle of the fused portion 13" is established.

In addition, in addition to the difference in hydrophilicity caused by the presence of the fused portions 13 and the non-fused portions 14 having different hydrophilicities on the first surface 10a of the laminated nonwoven fabric 10, , when the first surface 10a is viewed in units of predetermined regions having an area larger than that of the fused portion 13, there is also a difference in hydrophilicity between the regions. That is, as shown in FIG. 6, when a unit area 15 having a square shape in a plan view of 10 mm square including the fused portion 13 is virtually provided on the first surface 10a, the first surface 10a has a surface hydrophilicity of There are high hydrophilicity regions 15A, which are unit regions with relatively high surface hydrophilicity, and low hydrophilicity regions 15B, which are unit regions with relatively low surface hydrophilicity. The "surface hydrophilicity" here is different from the above-mentioned "hydrophilicity", and the index is the "contact angle of the fiber layer (nonwoven fabric), which is an aggregate of fibers, with water", and the contact angle is small. The higher the contact angle, the lower the surface hydrophilicity (higher surface hydrophobicity). However, surface hydrophilicity is measured by a different method from that of hydrophilicity because it targets a region having a larger area than hydrophilicity. Surface hydrophilicity is measured by the following method.

<Method for measuring surface hydrophilicity>
A unit area 15 having a square shape in a plan view and measuring 10 mm square including the fused portion 13 is cut out from the fiber layer (nonwoven fabric) to be measured to obtain a measurement sample. If the fiber layer (nonwoven fabric) to be measured is placed on an absorbent article such as a diaper, cold spray is sprayed on the absorbent article such as a diaper to solidify the adhesive and the fiber layer (nonwoven fabric) to be measured ) is removed, and from the removed fiber layer (nonwoven fabric), a 10 mm square unit area 15 including the fused portion 13 and having a square shape in a plan view is cut out and used as a measurement sample. The measurement sample includes an end face parallel to the direction (CD direction) perpendicular to the flow direction (MD direction) of the fiber layer during manufacturing, and the fiber layer is arranged in the absorbent article. In some cases, end faces parallel to the lateral direction of the absorbent article are included. A droplet of deionized water is attached to the surface of the measurement sample for contact angle measurement, the droplet is recorded, and the contact angle is measured based on the recorded image. More specifically, a microscope VHX-1000 manufactured by KEYENCE CORPORATION is used as a measuring device, and a medium-magnification zoom lens is attached to the microscope in a state tilted at 90°. The measurement sample is set on the measurement stage of the measurement apparatus so that the surface to be measured faces upward and can be observed from the CD direction of the measurement sample. Then, a droplet of 3 μL of deionized water is attached to the surface to be measured of the measurement sample set on the measurement stage, and the image of the droplet is recorded and loaded into the measuring device. Among the recorded images, select 10 images in which both ends or one end of the droplet in the CD direction or the lateral direction of the absorbent article is clear, and the contact angle of the droplet for each of the 10 images is 1 after the decimal point. The contact angle between the fiber layer (nonwoven fabric), which is an aggregate of the fibers, and water, that is, the "surface hydrophilicity" defined as The measurement environment is a room temperature of 22±2° C. and a humidity of 65±2% RH. A smaller contact angle value means a higher hydrophilicity.

The laminated nonwoven fabric 10 configured as described above has excellent liquid absorption performance and can effectively suppress liquid residue. That is, in the laminated nonwoven fabric 10, there is a relationship of "hydrophilicity of the non-fused portion 14 of the first surface 10a<hydrophilicity of the non-fused portion 14 of the second surface 10b". The side has lower inherent hydrophilicity (hydrophilicity before compression processing for forming the fused portion 13) than the second surface 10b side. Therefore, when the first surface 10a with relatively low hydrophilicity is used as the skin-facing surface of a skin-contacting sheet such as the sweat-absorbing sheet 4 or the topsheet 21, the skin-facing surface ( A hydrophilicity gradient is imparted in which the degree of hydrophilicity increases from the first surface 10a side) toward the non-skin facing surface side (second surface 10b side). The skin-contacting sheet having such a hydrophilic gradient is excellent in liquid drawing property from the side of the first surface 10a to the side of the second surface 10b, and quickly absorbs body fluids such as urine and sweat existing on the first surface 10a. Since it is pulled in, the problem of liquid remaining on the first surface 10a is effectively suppressed.

In addition, the first surface 10a of the laminated nonwoven fabric 10 is inherently less hydrophilic than the second surface 10b, and typically the non-fused portion 14 of the first surface 10a is inherently hydrophobic (see the method described above). The contact angle measured by the above method is 90 degrees or more), so when the first surface 10a is the skin-facing surface of the skin-contacting sheet, the skin-facing surface is hydrophilic (contact angle measured by the above method). Compared to cases where the angle is less than 90 degrees), the feeling of dryness after absorbing the liquid is improved, so the skin tends to be kept dry after absorbing the body fluid, causing discomfort due to stickiness, eczema, heat rash, rash, etc. of skin troubles are effectively reduced. On the first surface 10a, in addition to the non-fused portion 14 that maintains its inherent hydrophobicity, there is a fused portion 13 that is less hydrophobic and more hydrophilic than the non-fused portion 14. Therefore, even if the first surface 10a of the laminated nonwoven fabric 10 forming the skin-facing surface of the skin-contacting sheet is originally hydrophobic, aqueous liquids such as body fluids are likely to adhere to the first surface 10a, thereby improving the liquid absorption performance. realizable. That is, on the first surface 10a, since there is a difference in hydrophilicity between the fused portion 13 and the non-fused portion 14 surrounding it, the bodily fluid adhering to the wearer's skin is It preferentially adheres to the periphery thereof, and is absorbed toward the second surface 10b through the periphery of the fused portion 13 and the vicinity thereof.

In addition, the first surface 10a of the laminated nonwoven fabric 10 has a fused portion 13 having a relatively high degree of hydrophilicity and a non-fused portion 14 having a relatively low degree of hydrophilicity and is typically hydrophobic. Therefore, in the case where the first surface 10a is the skin-facing surface of the skin-contacting sheet, if the diaper 1 is worn, the liquid returns, and the liquid flows from the second surface 10b toward the first surface 10a. When the liquid is transferred, the transfer of the liquid is inhibited at least in the non-fused portion 14, so the liquid return is suppressed. The effect of suppressing liquid return is particularly remarkable in the surface sheet 21, which is a skin-contacting sheet placed at a position overlapping the absorber 4, and the urine once absorbed by the surface sheet 21 returns to the wearer's skin side. Inconvenience to do is suppressed effectively.

In particular, on the first surface 10a of the laminated nonwoven fabric 10, in addition to the hydrophilicity difference (microscopic hydrophilicity difference) between the fused portions 13 and the non-fused portions 14, which have relatively small areas, a 10 mm square There is a hydrophilicity difference (macrohydrophilicity difference) between the relatively large areas of the high hydrophilicity region 15A and the low hydrophilicity region 15B, which are square in plan view, and the hydrophilicity of the entire first surface 10a is Since it is clearly non-uniform, the effect of suppressing liquid residue and liquid return described above and the dry feeling after liquid absorption are exhibited when the first surface 10a is the skin-facing surface of the skin-contacting sheet. The effect is a particularly remarkable effect that cannot be achieved with the conventional technology.

As described above, in the absorbent article of the present invention, the surface sheet as the skin-contacting sheet is unlikely to cause liquid return, and the sweat-absorbing sheet as the skin-contacting sheet quickly absorbs perspiration to keep the wearer's skin dry. It can diffuse away from the skin and quickly evaporate the absorbed sweat. Therefore, according to the absorbent article of the present invention, it is possible to effectively prevent skin troubles caused by stuffiness and wetness, such as rashes after perspiration. The liquid absorption performance as the surface sheet can be evaluated as the amount of liquid returned, and the liquid absorption performance as the sweat absorbent sheet can be evaluated as the amount of residual liquid.

From the viewpoint of ensuring the effects described above, the contact angle, which is an index of the hydrophilicity and surface hydrophilicity of each part of the laminated nonwoven fabric 10, preferably falls within the following specific range.
The contact angle of the non-fused portion 14 of the first surface 10a is greater than the contact angle of the non-fused portion 14 of the second surface 10b, that is, the degree of hydrophilicity of the non-fused portion 14 of the first surface 10a<second On the premise of "hydrophilicity of non-fused portion 14 of surface 10b", it is preferably 80 degrees or more, more preferably 90 degrees or more, and preferably 140 degrees or less, more preferably 135 degrees or less.
The contact angle of the non-fused portion 14 on the second surface 10b is smaller than the contact angle of the non-fused portion 14 on the first surface 10a. On the premise of "hydrophilicity of the non-fused portion 14 of the surface 10a", it is preferably 30 degrees or more, more preferably 40 degrees or more, and preferably 80 degrees or less, more preferably 70 degrees or less.
The difference between the contact angle of the non-fused portion 14 of the first surface 10a and the contact angle of the non-fused portion 14 of the second surface 10b is preferably 3 degrees or more assuming that the former > the latter, and the former minus the latter. More preferably 5 degrees or more, preferably 70 degrees or less, more preferably 65 degrees or less.

The contact angle of the fused portion 13 on the first surface 10a is smaller than the contact angle of the non-fused portion 14 on the first surface 10a. is preferably 55 degrees or more, more preferably 60 degrees or more, and preferably 90 degrees or less, more preferably 85 degrees or less.
The difference between the contact angle of the non-fused portion 14 on the first surface 10a and the contact angle of the fused portion 13 on the first surface 10a is premised on the former > the latter, and the difference between the former and the latter is preferably 3 degrees or more, or more. It is preferably 5 degrees or more, preferably 45 degrees or less, more preferably 40 degrees or less.

The contact angle of the high hydrophilicity region 15A measured by the above method is smaller than that of the low hydrophilicity region 15B, that is, "surface hydrophilicity of high hydrophilicity region 15A > surface hydrophilicity of low hydrophilicity region 15B". On the premise that there is, it is preferably 75 degrees or more, more preferably 80 degrees or more, and preferably 105 degrees or less, more preferably 100 degrees or less.
The contact angle of the low hydrophilicity region 15B measured by the above method is larger than that of the high hydrophilicity region 15A, that is, "surface hydrophilicity of low hydrophilicity region 15B<surface hydrophilicity of high hydrophilicity region 15A". On the premise that there is, it is preferably 65 degrees or more, more preferably 70 degrees or more, and preferably 115 degrees or less, more preferably 110 degrees or less.
The difference between the contact angle of the low hydrophilicity region 15B and the contact angle of the high hydrophilicity region 15A is, on the premise that the former > the latter, the former minus the latter, preferably 3 degrees or more, more preferably 5 degrees or more, and preferably is 30 degrees or less, more preferably 25 degrees or less.

Since both the high hydrophilicity region 15A and the low hydrophilicity region 15B are unit regions 15 having a square shape in a plan view of 10 mm square including the fused portion 13, the factors affecting the surface hydrophilicity of the unit region 15 are includes not only the hydrophilicity of the fused portion 13 itself, but also the area of the fused portion 13, the density of the fused portion 13 (the number per unit area of the fused portion 13), and the like. In other words, one unit region 15 and another unit region 15 on the first surface 10a of the laminated nonwoven fabric 10 are affected by the factors affecting the surface hydrophilicity of the unit region 15 (one fused portion 13 Hydrophilicity, area of one fused portion 13, number of fused portions 13) are made different from each other so that high hydrophilicity region 15A and low hydrophilicity region 15B exist on first surface 10a. , it becomes possible to impart the above-mentioned macroscopic hydrophilicity difference.

For example, the hydrophilicity of one fused portion 13 included in the high hydrophilicity region 15A is higher than the hydrophilicity of one fused portion 13 included in the low hydrophilicity region 15B, and such fused The difference in hydrophilicity between the portions 13 (microscopic difference in hydrophilicity) contributes to the expression of the macroscopic difference in hydrophilicity that "the surface hydrophilicity of the high-hydrophilicity region 15A > the surface hydrophilicity of the low-hydrophilicity region 15B". There may be cases. In such a case, the difference in hydrophilicity between the fused portions 13 in the high hydrophilicity region 15A and the low hydrophilicity region 15B is based on the comparison between the fused portions 13 having the same area. It can also be said that "the difference in hydrophilicity per unit area of the attachment portion 13".

The hydrophilicity of the fused portion 13 can be controlled by the fused strength of the plurality of fiber layers 11 and 12 integrally fused at the fused portion 13 . According to the findings of the present inventors, increasing the compressive strength during compression processing such as hot embossing for forming the fused portion 13 improves the hydrophilicity of the fused portion 13 (decreases the contact angle), When the compressive strength is weakened, the hydrophilicity of the fused portion 13 tends to decrease (the contact angle increases). This is based on the premise that there is inherently a hydrophilicity difference between the plurality of fiber layers 11 and 12, which are the objects to be processed. The constituent fibers 11F and 12F of 11 and 12 are sufficiently melted, and as a result, on the first surface 10a composed of the fiber layer 11 having relatively low hydrophilicity, the hydrophilicity of the fused portion 13, which is the portion to be compressed, is reduced. However, it is presumed that this is due to the improvement compared to the non-fused portion 14 which is not subjected to compression processing and maintains its original hydrophilicity. If the compressive strength during compression processing is weak, the constituent fibers 11F and 12F in the compressed portion are insufficiently melted. Hydrophilicity hardly changes, and as a result, the hydrophilicity of the fused portion 13 and the non-fused portion 14 on the first surface 10a becomes substantially the same.

The contact angle of the fused portion 13 included in the high hydrophilicity region 15A measured by the <Method for Measuring Hydrophilicity> is smaller than that of the fused portion 13 included in the low hydrophilicity region 15B. On the premise that the hydrophilicity of the fused portion 13 in the hydrophilic region 15A>the hydrophilicity of the fused portion 13 in the low hydrophilicity region 15B", preferably 55 degrees or more, more preferably 60 degrees or more, and , preferably 90 degrees or less, more preferably 85 degrees or less.
The contact angle of the fused portion 13 included in the low hydrophilicity region 15B measured by the <method for measuring hydrophilicity> is larger than that of the fused portion 13 included in the high hydrophilicity region 15A, that is, “low On the premise that the hydrophilicity of the fused portion 13 in the hydrophilic region 15B<hydrophilicity of the fused portion 13 in the high hydrophilicity region 15A", preferably 55 degrees or more, more preferably 60 degrees or more, and , preferably 90 degrees or less, more preferably 85 degrees or less.
In some cases, the fused portion 13 included in the high hydrophilicity region 15A and the fused portion 13 included in the low hydrophilicity region 15B have the same hydrophilicity (contact angle). The density of the fused portions 13 (the number of fused portions 13 per unit area) is different between the former and the latter, and the density of the fused portions 13 is greater than the former.

Further, for example, as shown in FIG. 8, the area of one fused portion 13 included in the high hydrophilicity region 15A is larger than the area of one fused portion 13 included in the low hydrophilicity region 15B. When the difference in area between the fused portions 13 is large and contributes to the manifestation of a macroscopic hydrophilicity difference such as "surface hydrophilicity of the high hydrophilicity region 15A>surface hydrophilicity of the low hydrophilicity region 15B". can be. That is, even if the number of fused portions 13 and the hydrophilicity of each fused portion 13 (compressive strength when forming the fused portions 13) are the same in the high hydrophilicity region 15A and the low hydrophilicity region 15B, each fused portion If the area of the portion 13 is different, a macroscopic hydrophilicity difference may occur between the regions 15A and 15B.

On the premise that the area of one fused portion 13 included in the high hydrophilicity region 15A is larger than that of the fused portion 13 included in the low hydrophilicity region 15B, it is preferably 0.3 mm ² or more, or more. It is preferably 0.4 mm ² or more, preferably 1.5 mm ² or less, more preferably 1.4 mm ² or less.
On the premise that the area of one fused portion 13 included in the low hydrophilicity region 15B is smaller than that of the fused portion 13 included in the high hydrophilicity region 15A, it is preferably 0.1 mm ² or more, or more. It is preferably 0.2 mm ² or more, preferably 1.3 mm ² or less, more preferably 1.2 mm ² or less.

Further, for example, as shown in FIG. 9, the number of fused portions 13 included in the high hydrophilicity region 15A is larger than the number of fused portions 13 included in the low hydrophilicity region 15B), such a unit The difference in the number of fused portions 13 per area (10 mm×10 mm) contributes to the development of a macro hydrophilicity difference of “surface hydrophilicity of high hydrophilicity region 15A>surface hydrophilicity of low hydrophilicity region 15B”. It is possible that In FIG. 9, nine fused portions 13 are included in the high hydrophilicity region 15A, and four fused portions 13 are included in the low hydrophilicity region 15B. That is, even if the hydrophilicity (compressive strength when forming the fused portion 13) and area of one fused portion 13 are the same in the high hydrophilicity region 15A and the low hydrophilicity region 15B, the unit of the fused portion 13 is If the number per area is different, a macro hydrophilicity difference may develop between the regions 15A and 15B.

On the premise that the number of fused portions 13 included in the high hydrophilicity region 15A is greater than the number of the fused portions 13 included in the low hydrophilicity region 15B, preferably 4 or more, more preferably 6 or more. , and preferably 50 or less, more preferably 40 or less.
On the premise that the number of fused portions 13 included in the low hydrophilicity region 15B is less than the number of fused portions 13 included in the high hydrophilicity region 15A, preferably 4 or more, more preferably 6 or more. , and preferably 50 or less, more preferably 40 or less.
In some cases, the high hydrophilicity region 15A and the low hydrophilicity region 15B have the same number of fused portions 13. In this case, the degree of hydrophilicity (contact angle) and The areas are different, and for example, the hydrophilicity of the fused portion 13 is region 15A>region 15B (the contact angle is region 15A<region 15B).

On the first surface 10a of the laminated nonwoven fabric 10, the distribution pattern of the high hydrophilicity regions 15A and the low hydrophilicity regions 15B is not particularly limited, and depends on the type and application of the skin contact sheet to which the laminated nonwoven fabric 10 is applied. It can be set as appropriate.

For example, the surface sheet 21, which is the skin-contacting sheet, includes the laminated nonwoven fabric 10, the skin-facing surface of the surface sheet 21 is the first surface 10a of the laminated nonwoven fabric 10, and the skin-facing surface of the surface sheet 21 ( On the first surface 10a), the high hydrophilicity region 15A extends in the longitudinal direction X, and the low hydrophilicity region 15B extends along the high hydrophilicity region 15A on both sides of the high hydrophilicity region 15A in the horizontal direction Y. A configuration extending in the longitudinal direction X is possible. As a specific example of such a form, there is a form in which the high hydrophilicity region 15A is positioned at the center of the topsheet 21 in the lateral direction Y, and the low hydrophilicity region 15B is positioned at both sides of the topsheet 21 in the lateral direction Y. be done. According to such a configuration, since both ends in the lateral direction Y of the surface facing the skin of the topsheet 21 are the low hydrophilicity regions 15B, lateral leakage can be effectively prevented. In addition, in the diaper 1, as shown in FIGS. 2 and 3, the leak-proof cuff 26 is arranged so as to cover the edge of the skin-facing surface of the topsheet 21 in the horizontal direction Y. The length (width) in the lateral direction Y of the low-hydrophilicity region 15B arranged in the horizontal direction is longer than the length (width) in the same direction of the portion covered by the leak-proof cuff 26 on the skin-facing surface of the topsheet 21. By doing so, the low hydrophilicity region 15B and the leak-preventing cuff 26 can work together to prevent side leakage more effectively.

Further, for example, the surface sheet 21, which is the skin-contacting sheet, includes the laminated nonwoven fabric 10, and the skin-facing surface of the surface sheet 21 is the first surface 10a of the laminated nonwoven fabric 10, and the skin-facing surface of the surface sheet 21. In (the first surface 10a), there may be a mode in which a high hydrophilicity region 15A exists in the portion facing the excretory part, and a low hydrophilicity region 15B exists so as to surround the high hydrophilicity region 15A. According to such a configuration, the high hydrophilicity region 15A is positioned in the portion facing the excretion part where body fluids such as urine are first excreted, so that the excreted body fluids can be transferred to the laminated nonwoven fabric via the high hydrophilicity region 15A. The presence of the low hydrophilicity region 15B that surrounds the high hydrophilicity region 15A while rapidly migrating to the inside in the thickness direction of 10 effectively prevents not only lateral leakage but also leakage from the front and rear ends in the vertical direction X. can be prevented.

Further, for example, the sweat-absorbent sheet 4 which is the skin-contacting sheet includes the laminated nonwoven fabric 10, and the skin-facing surface of the sweat-absorbent sheet 4 is the first surface 10a of the laminated nonwoven fabric 10, and the skin-facing surface of the sweat-absorbent sheet 4. In (the first surface 10a), there may be a form in which the low hydrophilicity region 15B exists outside the high hydrophilicity region 15A in the longitudinal direction X. As a specific example of such a form, the low hydrophilicity region 15B extends in the horizontal direction Y at the end of the sweat absorbent sheet 4 in the vertical direction X, and the low hydrophilicity region 15B extends inward in the vertical direction X from the low hydrophilicity region 15B. A form in which the high hydrophilicity region 15A extends in the horizontal direction Y is exemplified. According to such a configuration, leakage from the ends of the diaper 1 in the longitudinal direction X can be effectively prevented while bodily fluids such as sweat around the waist of the wearer are absorbed.

On the second surface 10b of the laminated nonwoven fabric 10, similarly to the first surface 10a, there are the fused portions 13 and the non-fused portions 14 (see FIG. 7). The fused portion 14 has a higher degree of hydrophilicity than the fused portion 13 . This is in contrast to the fact that the non-fused portion 14 is less hydrophilic than the fused portion 13 on the first surface 10a, as described above. The reason why the degree of hydrophilicity between the fused portion 13 and the non-fused portion 14 on the second surface 10b is opposite to that on the first surface 10a is that This is because the hydrophilicity of 14 is relatively high. That is, on the second surface 10b formed from the fiber layer 12, the non-fused portion 14, which is not subjected to compression processing such as heat embossing for forming the fused portion 13, is formed in the fiber layer 12 (the constituent fibers 12F ) maintains the original hydrophilicity, but in the fused portion 13, the fiber layer 11 (constituent fiber 11F) having relatively low hydrophilicity and the fiber layer 12 (constituent fiber 12F) having relatively high hydrophilicity are formed. is melted by the compression processing, the hydrophilicity decreases compared to before compression processing (the contact angle measured by the above method increases). Therefore, on the second surface 10b of the laminated nonwoven fabric 10, as described above, the relationship of "hydrophilicity of the unfused portion 14>hydrophilicity of the fused portion 13" is established. A magnitude relationship of angle <contact angle of fused portion 13 is established.

In this way, on the second surface 10b of the laminated nonwoven fabric 10 as well as on the first surface 10a, there is a difference in hydrophilicity (microscopic difference in hydrophilicity) between the fused portions 13 and the non-fused portions 14. Therefore, even when the second surface 10b is the skin-facing surface of the skin-contacting sheet, the same effects as when the first surface 10a is the skin-facing surface of the skin-contacting sheet can be obtained. However, the micro-hydrophilicity difference on the second surface 10b is opposite to that on the first surface 10a. From the viewpoint of improving the dry feeling after absorbing the liquid, it is preferable that the first surface 10a is the skin-facing surface of the skin-contacting sheet.

In the laminated nonwoven fabric 10, the hydrophilicity of the fused portions 13 on one or both of the first surface 10a and the second surface 10b is higher than the hydrophilicity of the non-fused portions 14 on the first surface 10a, and It is lower than the hydrophilicity of the non-fused portion 14 on the second surface 10b. In other words, regarding the hydrophilicity of the laminated nonwoven fabric 10, "non-fused portion 14 on first surface 10a<fused portion 13 on first surface 10a, fused portion 13 on second surface 10b<non-fused portion on second surface 10b" In other words, regarding the contact angle, "non-fused portion 14 on first surface 10a>fused portion 13 on first surface 10a, fused portion 13 on second surface 10b>second A size relationship of "non-fused portion 14 of surface 10b" is established. By establishing such a magnitude relationship of hydrophilicity, the laminated nonwoven fabric 10 is reliably provided with a hydrophilicity gradient in which the hydrophilicity increases from the first surface 10a side to the second surface 10b side, and the second surface 10b side. Since the difference in hydrophilicity between the fused portion 13 and the non-fused portion 14 is reliably imparted to the one surface 10a, the predetermined effects of the present invention can be achieved more reliably.

On the premise that the contact angle of the fused portion 13 of the second surface 10b is larger than the contact angle of the non-fused portion 14 of the second surface 10b, it is preferably 55 degrees or more, more preferably 60 degrees or more, and It is preferably 90 degrees or less, more preferably 85 degrees or less.
The difference between the contact angle of the fused portion 13 of the second surface 10b and the contact angle of the non-fused portion 14 of the second surface 10b is, on the premise that the former > the latter, the former minus the latter, preferably 3 degrees or more, or more. It is preferably 5 degrees or more, preferably 30 degrees or less, and more preferably 25 degrees or less.
The contact angle of the non-fused portion 14 of the second surface 10b is as described above.

As the constituent fibers 11F of the fiber layer 11 constituting the first surface 10a of the laminated nonwoven fabric 10, those having a lower hydrophilicity than the constituent fibers 12F of the fiber layer 12 constituting the second surface 10b are used. Hydrophobic fibers are used. As hydrophobic fibers, hydrophobic synthetic fibers, especially hydrophobic thermoplastic fibers can be used. Examples of thermoplastic fiber materials include polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET); polyamides such as nylon 6 and nylon 66; polyacrylic acid and polymethacrylic acid alkyl esters. , polyvinyl chloride, polyvinylidene chloride, etc., and these can be used alone or in combination of two or more.

The fiber layer 11 is preferably composed mainly of hydrophobic fibers and is hydrophobic. The ratio of the hydrophobic fibers to all constituent fibers of the fiber layer 11 is at least 50% by mass or more, preferably 70% by mass or more, and may be 100% by mass.

As the constituent fibers 12F of the fiber layer 12 constituting the second surface 10b of the laminated nonwoven fabric 10, those having a higher hydrophilicity than the constituent fibers 11F of the fiber layer 11 constituting the first surface 10a are used. Hydrophilic fibers are used. As hydrophilic fibers, hydrophilic synthetic fibers, particularly hydrophilic thermoplastic fibers can be used. For example, inherently hydrophilic thermoplastic fibers made of hydrophilic thermoplastic resins such as polyacrylonitrile fibers Alternatively, it may be one obtained by subjecting an inherently hydrophobic thermoplastic fiber made of a hydrophobic thermoplastic resin to a hydrophilic treatment, and these may be used alone or in combination of two or more. can. Examples of the latter "hydrophilized thermoplastic fibers" include thermoplastic fibers kneaded with a hydrophilizing agent, thermoplastic fibers having a hydrophilizing agent attached to the surface, and plasma-treated thermoplastic fibers. etc. As the hydrophilizing agent, general hydrophilizing agents (such as various surfactants) used for sanitary products can be used without particular limitation.

The fiber layer 12 is preferably composed mainly of hydrophilic fibers and is hydrophilic. The ratio of the hydrophilic fibers to all constituent fibers of the fiber layer 12 is at least 50% by mass or more, preferably 70% by mass or more, and may be 100% by mass.

Each of the constituent fibers 11F and 12F of the laminated nonwoven fabric 10 may be a single fiber made of one type of synthetic resin or a blend polymer obtained by mixing two or more types of synthetic resins, or may be a composite fiber. The composite fiber referred to here is a synthetic fiber obtained by combining two or more types of synthetic resins with different components with a spinneret and spinning them at the same time. It refers to those that are mutually bonded within the fiber. The form of the composite fiber includes core-sheath type, side-by-side type, etc., and is not particularly limited.

The constituent fibers 11F and 12F of the laminated nonwoven fabric 10 may be short fibers (staple) or long fibers (filament). That is, each of the fiber layers 11 and 12 may be a short-fiber nonwoven fabric such as an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlaced nonwoven fabric, a needle-punched nonwoven fabric, or a chemical-bonded nonwoven fabric, or may be a long-fiber nonwoven fabric such as a spunbond nonwoven fabric or a meltblown nonwoven fabric. . The term "short fiber" as used herein means a fiber having a fiber length of 100 mm or less, preferably 15 mm or more, and the term "long fiber" means a fiber having a fiber length of 30 mm or more. In particular, so-called continuous filaments having a fiber length of 150 mm or more are preferable because a filament nonwoven fabric having high breaking strength can be obtained. In addition, the upper limit of the fiber length in the said "long fiber" is not specifically limited.

The basis weight (basis weight) of the fiber layer 11 and the fiber layer 12 is preferably 24 g/m ² or more, more preferably 28 g/m 2 or more, from the viewpoint of not being bulky while ensuring practically sufficient strength and absorption capacity. m ² or more, preferably 45 g/m ² or less, more preferably 40 g/m ² or less.

Next, a method for manufacturing an absorbent article of the present invention will be described based on a method for manufacturing a diaper 1, which is a preferred embodiment thereof. The method for manufacturing the diaper 1 comprises a laminated nonwoven fabric forming at least one of the skin-contacting sheets (the sweat-absorbing sheet 4, the top sheet 21, the leakage-preventive cuff-forming sheet 27, and the inner layer sheet 32) of the diaper 1. 10 manufacturing steps, and a step of manufacturing the diaper 1 using the laminated nonwoven fabric 10 manufactured by the manufacturing steps. The manufacturing process of the diaper 1 using the laminated nonwoven fabric 10 can be carried out according to a conventional method.

FIG. 10 shows a production apparatus 50A, which is an embodiment of the apparatus for producing the laminated nonwoven fabric 10. As shown in FIG. The manufacturing apparatus 50A is an apparatus for manufacturing a staple fiber nonwoven fabric. It is used when it is a short fiber nonwoven fabric.

As shown in FIG. 10, the manufacturing apparatus 50A includes a web forming section 51 and a compression processing section 52 in this order from the upstream side to the downstream side (along the machine direction MD) of the manufacturing process of the laminated nonwoven fabric 10. do. The long laminated nonwoven fabric 10 manufactured through the compression processing section 52 is wound into a roll and used in the manufacturing process of the diaper 1 .

The web forming unit 51 is an apparatus for manufacturing the laminate 10W of the fiber webs 11W and 12W, which are the precursors of the laminated nonwoven fabric 10, which is the object of manufacture. has two web forming devices 510 and 511 . In this embodiment, the two web forming devices 510, 511 are carding machines 510, 511, respectively. As the carding machine, the same one as that commonly used in the production of nonwoven fabrics can be used without particular limitation. Instead of a carding machine, other web forming equipment, such as an airlaid equipment, can be used.

The compression processing unit 52 is a device that performs thermal embossing, which is a type of compression processing, on the workpiece (laminate 10W), and includes compression means 520 and receiving means 521 . In this embodiment, the compression means 520 is an engraved roll 520 in which a plurality of protrusions 5 are intermittently arranged on the peripheral surface of a cylindrical roll body (the surface facing the workpiece), and the receiving means 521 is It is a cylindrical smooth roll 521 with no irregularities on its peripheral surface, and both rolls 520 and 521 are arranged opposite to each other with the workpiece conveying path interposed therebetween. The engraving roll 520 has heating means such as a heater inside the roll body, and the heating means can heat the projections 5 to a predetermined temperature.

A manufacturing process of the laminated nonwoven fabric 10 carried out using the manufacturing apparatus 50A having the above configuration will be described. In such a manufacturing process, a plurality of fiber webs 11W and 12W are laminated to obtain a laminated body 10W, and the laminated body 10W is partially compressed in the thickness direction by compression and heated to form a compressed portion of the laminated body 10W. and a fused portion forming step for forming the fused portion 13 in the second step.

First, as shown in FIG. 10, fiber webs 11W and 12W are respectively formed in the web forming section 51 to form a laminated body 10W. Specifically, in the web forming apparatus 510, a long fiber web 11W is formed using the constituent fibers 11F described above as a raw material, and then a long fiber web 12W is formed on the running fiber web 11W. are directly laminated to obtain a long laminate 10W. The fiber web 12W is formed by a web forming device 511 located downstream of the web forming device 510 in the machine direction MD, using the constituent fibers 12F described above as raw materials. In each of the fiber webs 11W and 12W constituting the laminate 10W, the constituent fibers 11F and 12F are loosely entangled with each other, and the shape retention property as a sheet-like fiber layer is not obtained.

Next, as shown in FIG. 10, the laminated body 10W is subjected to compression processing in the compression processing section 52 to form the fused portions 13, thereby manufacturing the laminated nonwoven fabric 10 (fused portion forming step). Specifically, the laminated body 10W is supplied between the engraved roll 520 and the smoothing roll 521, and the laminated body 10W is smoothed while the convex portions 5 of the engraved roll 520 heated to a predetermined temperature are brought into contact with the laminated body 10W. By pressing to the roll 521 side, the laminate 10W is partially compressed in the thickness direction and heated. In this embodiment, the laminate 10W is pressed by the projections 5 from the side of the fiber web 11W, which is the precursor of the fiber layer 11 . By subjecting the layered body 10W to compression processing accompanied by a melting promoting means (heat in this embodiment) that promotes melting of the constituent fibers 11F and 12F, the compressed portion of the layered body 10W (with the convex portion 5 At the contact portion), the constituent fibers 11F and 12F are melted and fused, and the compressed portion becomes the fused portion 13 . The laminated body 10W in which the fused portion 13 is formed is the laminated nonwoven fabric 10 having shape retention as a sheet-shaped nonwoven fabric.

The manufacturing process of the laminated nonwoven fabric 10 using the manufacturing apparatus 50A described above is applied when the laminated nonwoven fabric 10 to be manufactured is a short-fiber nonwoven fabric. When the laminated nonwoven fabric 10 to be manufactured is a long-fiber nonwoven fabric, for example, a manufacturing apparatus 50B shown in FIG. 11 can be used. Concerning the manufacturing apparatus 50B, the components different from those of the manufacturing apparatus 50A will be mainly described, and the same components will be denoted by the same reference numerals, and description thereof will be omitted. The description of the manufacturing apparatus 50A is appropriately applied to components that are not particularly described.

The web forming unit 51 provided in the manufacturing apparatus 50B includes a conveyer 512 and spinning devices 513 and 514, which are the same in number as the fiber webs forming the laminate 10W, which are two in this embodiment. The spinning devices 513 and 514 are arranged above the transfer conveyor 512 . The spinning devices 513, 514 respectively comprise spinning heads 513h, 514h for spinning the fibers 11F, 12F toward the transport conveyor 512 below. As the spinning devices 513 and 514, those commonly used in the production of nonwoven fabrics can be used without particular limitation.

In the web forming section 51 of the manufacturing device 50B, the fibers 11F are spun from the spinning head 513h of the spinning device 513, deposited on the conveyer 512 to form the fiber web 11W, and then the running fiber web 11W is coated with the fiber 11F. The fibers 12F are spun from the spinning head 514h of the spinning device 514, and the fibers 12F are deposited directly on the fiber web 11W to obtain the long laminate 10W. Thus, the manufacturing apparatus 50B employs a direct spinning method in which the fibers 12F are directly spun onto the fiber web 11W by a melt spinning method or the like.

On the first surface 10a of the laminated nonwoven fabric 10 manufactured by the manufacturing apparatus 50A or 50B, as shown in FIG. In addition, when viewed from the unit area 15 having a square shape in a plan view of 10 mm square including the fused part 13, the high hydrophilicity area 15A having a relatively high surface hydrophilicity and the surface hydrophilicity In the planar direction of the laminated nonwoven fabric 10, there is a micro hydrophilicity difference between the fused portions 13 and the non-fused portions 14 and the high hydrophilicity region 15A. and the low hydrophilicity region 15B.

Conventionally, when providing a hydrophilicity difference in the plane direction of a nonwoven fabric, a fiber treatment agent such as a hydrophilizing agent that increases the hydrophilicity of the constituent fibers of the nonwoven fabric is applied to predetermined locations of the nonwoven fabric or its precursor fiber web. A coating method is used. However, in this method, due to the operation of "partial application of the agent", there are problems such as uneven application of the agent, strike-through, and peripheral areas of the planned application area (no application of the hydrophilizing agent is planned). There is a problem that the agent oozes out to the part), the agent scatters, and the manufacturing equipment is contaminated due to poor drying after application.

In view of such problems in the prior art, in the manufacturing method of the present invention, the above-described hydrophilicity difference is provided in the laminated nonwoven fabric 10 without performing "partial application of the agent". According to the findings of the present inventors, by adjusting the strength of the compressive strength (the pressure applied to the compressed portion of the workpiece) during compression processing such as hot embossing for forming the fused portion 13, the fused portion 13 can be fused. It is possible to adjust the degree of hydrophilicity of the adhesive portion 13. By increasing the compressive strength, the degree of hydrophilicity of the fused portion 13 is improved (the contact angle is decreased), and by decreasing the compressive strength, It is possible to reduce the hydrophilicity of the fused portion 13 (increase the contact angle). Based on such knowledge, in the manufacturing method of the present invention, the laminated body 10W is partially subjected to compression processing to partially form the fused portion 13 without performing "partial application of the agent". , By providing a microscopic difference in hydrophilicity between the fused portion 13 and the non-fused portion 14 in the plane direction of the laminated nonwoven fabric 10 and partially varying the compressive strength during compression processing, high hydrophilicity A macro hydrophilicity difference is provided between the region 15A and the low hydrophilicity region 15B.

Providing a macro hydrophilicity difference between the high hydrophilicity region 15A and the low hydrophilicity region 15B in the plane direction of the laminated nonwoven fabric 10 is one region and another region in the planar view of the laminated body 10W, which is the object to be processed. It is also possible by changing not only the "pressure applied to the compressed part" (compressive strength), but also the "area of the compressed part" and the "number of compressed parts per unit area" depending on the region of the part. . In the compression processing of the laminate 10W, when only the “area of the compressed portion” is partially changed, the high hydrophilicity region 15A and the low hydrophilicity region 15B of the laminated nonwoven fabric 10 thus manufactured are, for example, shown in FIG. 8, the fused portion 13 in the high hydrophilicity region 15A has a larger area than the fused portion 13 in the low hydrophilicity region 15B. Also, in the compression processing of the laminate 10W, when only the "number of compressed parts per unit area" is partially changed, the high hydrophilicity region 15A and the low hydrophilicity of the laminated nonwoven fabric 10 manufactured in this way The region 15B is, for example, as shown in FIG. 9, and the number of fused portions 13 is larger in the high hydrophilicity region 15A than in the low hydrophilicity region 15B.

In short, in the method of manufacturing the diaper 1, in the fusion-bonded portion forming step, the "pressure applied to the compressed portion" is determined between a part of the area and the other part of the laminate 10W, which is the workpiece, in a plan view. (compressive strength), "area of compressed portions", and "number of compressed portions per unit area" are different. And, due to such characteristics, by simply performing compression processing, high hydrophilicity regions can be formed in the plane direction of the laminated nonwoven fabric 10 without using the conventional method of imparting a hydrophilicity difference by separately coating the fiber treatment agent. It becomes possible to provide a macro hydrophilicity difference between 15A and the low hydrophilicity region 15B.

In the compression processing of the laminate 10W in the present embodiment, an engraving roll 520, which is compression means having a plurality of protrusions 5 intermittently arranged on the surface facing the workpiece, is used to press the laminate 10W with the protrusions 5. By doing so, the laminate 10W is compressed in the thickness direction. Therefore, by appropriately adjusting the pattern (shape and arrangement) of the convex portions 5, the aforementioned "pressure applied to the compressed portion", "area of the compressed portion", and "number of compressed portions per unit area" can be partially different.

12(a) to 12(c) illustrate patterns A to C of the convex portions 5 on the engraved roll 520. FIG. By applying one or more patterns selected from the group consisting of patterns A to C to the surface (peripheral surface) 520a of the engraving roll 520 facing the workpiece (laminate 10W), the laminated nonwoven fabric 10 is formed. It is possible to provide a macro hydrophilicity difference between the high hydrophilicity region 15A and the low hydrophilicity region 15B in the planar direction.

The pattern A shown in FIG. 12(a) has a region P1 having a convex portion 5A having a relatively high height H from the facing surface 520a and a region P2 having a convex portion 5B having a relatively low height H. It is a pattern that exists. The compressive strength of the portion to be compressed pressed by the convex portion 5A having a relatively high height H is stronger than the compressive strength of the portion to be compressed pressed by the convex portion 5B having a relatively low height H. Therefore, for example, the region formed in the laminated nonwoven fabric 10 by being pressed by the region P1 of the engraving roll 520 is the high hydrophilicity region 15A, and is formed in the laminated nonwoven fabric 10 by being pressed by the region P2 of the engraving roll 520. The region becomes the low hydrophilicity region 15B, and a macro hydrophilicity difference is imparted in the plane direction of the laminated nonwoven fabric 10 by the high hydrophilicity region 15A and the low hydrophilicity region 15B. Each of the regions P1 and P2 has an area in which a plurality of convex portions 5 can exist, and is typically larger than the unit region 15 (a 10 mm square region having a square shape in plan view). In some cases, it occupies half the area of the facing surface 520a. The same applies to regions P3 to P6, which will be described later.

Pattern B shown in FIG. 12B is a pattern in which a region P3 having a convex portion 5A having a relatively large top area S and a region P4 having a convex portion 5C having a relatively small top area S are present. . Since the convex portion 5A and the convex portion 5C have the same height H, the compressive strength applied to the compressed portion compressed by them is the same. and the single fused portion 13 formed in the compressed portion of the convex portion 5C have the same hydrophilicity. However, as for the total area of the fused portions 13, the area corresponding to the area P3 of the engraved roll 520 on the first surface 10a of the laminated nonwoven fabric 10 is larger than the area corresponding to the area P4 of the engraved roll 520. Therefore, the former has higher surface hydrophilicity than the latter. The high hydrophilicity region 15A shown in FIG. 8 is an example of the former (region corresponding to the region P3), and the low hydrophilicity region 15B shown in FIG. 8 is an example of the latter (region corresponding to the region P4). In this way, by pressing the workpiece (laminated body 10W) using the compressing means in which the convex portions 5 are arranged in the pattern B, the high hydrophilicity region 15A and the low hydrophilicity region are formed in the plane direction of the laminated nonwoven fabric 10. 15B can provide a macroscopic hydrophilicity difference. The preferable range of the top area S of each of the convex portion 5A having a relatively large top area S and the convex portion 5C having a relatively small top area S is the high hydrophilicity region 15A or the low hydrophilicity region described above. It is the same as the area of one fused portion 13 included in 15B.

A pattern C shown in FIG. 12(c) is a pattern in which a region P5 in which the interval G between adjacent convex portions 5A is relatively short and a region P6 in which the interval G is relatively long are present. The plurality of protrusions 5A in the pattern C have the same shape and size, and the gaps G are only partially different. As the interval G becomes shorter, the number of fused portions 13 included in the unit area (the density of the fused portions 13) increases, and as the interval G becomes longer, the density of the fused portions 13 decreases. The higher the density of the fused portion 13, the higher the surface hydrophilicity. It has a higher surface hydrophilicity than the corresponding area. The high hydrophilicity region 15A shown in FIG. 9 is an example of the former (region corresponding to the region P5), and the low hydrophilicity region 15B shown in FIG. 9 is an example of the latter (region corresponding to the region P6). In this way, by pressing the workpiece (laminated body 10W) using the compressing means in which the convex portions 5 are arranged in the pattern C, the high hydrophilicity region 15A and the low hydrophilicity region are formed in the plane direction of the laminated nonwoven fabric 10. 15B can provide a macroscopic hydrophilicity difference. Per unit area (10 mm × 10 mm) of the surface of the engraving roll 520, each of the convex portions 5A in a region P5 in which the interval G between the adjacent convex portions 5A is relatively short and in a region P6 in which the interval G is relatively long. A preferable range of the number is the same as the number of fused portions 13 included in the high hydrophilicity region 15A or the low hydrophilicity region 15B described above.

Although the present invention has been described above based on its preferred embodiments, the absorbent article of the present invention is not limited to the above embodiments and can be modified as appropriate.
For example, in the diaper 1, as shown in FIG. 4, the sweat absorbing sheet 4 is joined to the folded portion 31E of the outer layer sheet 31. However, the sweat absorbing sheet 4 alone is not joined to such other members, and the waist is adjusted to the waist. A flap WF may be configured.
In addition, in the diaper 1, as shown in FIG. 2, the outer body 3 has a continuous shape extending over the abdominal part F, the crotch part M, and the back side part R, but instead of this, the outer body 3 It may have a split type shape in which the abdominal exterior body, the dorsal exterior body, and the crotch exterior body are separated as separate members.
In addition, the absorbent article of the present invention is not limited to a pants-type disposable diaper such as the diaper 1 described above, but can be applied to general articles used for absorbing bodily fluids. can be applied to

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to such Examples.

[Examples 1 to 5 and Comparative Examples 1 and 2]
Using the manufacturing apparatus shown in FIG. 10, a laminated nonwoven fabric 10 having a two-layer structure consisting of fiber layers 11 and 12 was manufactured according to the manufacturing method described above. Concentric core-sheath composite fibers having a polyethylene terephthalate core and a polyethylene sheath were used as raw material fibers for the fiber webs 11W and 12W. The raw fibers of the fiber web 12W were coated with a hydrophilizing agent for increasing the hydrophilicity of the fibers. The basis weight of the fiber layer 11 was 8 g/m ² and the basis weight of the fiber layer 12 was 20 g/m ² . In the fused portion forming step, a part of the workpiece (laminated body 10W) in plan view (hereinafter also referred to as a “first region”) and the other region (hereinafter referred to as a “second region”) ), the workpiece is subjected to compression processing so that any one of the pressure applied to the compressed portion, the area of the compressed portion, and the number of compressed portions per unit area is different. .

[Comparative Example 3]
Except that a fluorine-based water and oil resistant agent (product name: AG-E060, manufactured by Asahi Glass Co., Ltd.) was applied to the entirety of the first surface 10a and the second surface 10b of the laminated nonwoven fabric 10, including the fused portions 13 and the non-fused portions 14. A laminated nonwoven fabric was produced in the same manner as in Examples 1 to 5 and Comparative Examples 1 and 2.

[Comparative Example 4]
Potassium stearyl phosphate (product name: gripper 4131 neutralized potassium hydroxide Kao Corporation) A laminated nonwoven fabric was produced in the same manner as in Examples 1 to 5 and Comparative Examples 1 and 2, except that the material was applied.

〔evaluation〕
Regarding the laminated nonwoven fabrics of each example and comparative example, the remaining liquid amount and the liquid retention amount were measured by the following methods. The results are shown in Table 1 below.

<Method for measuring remaining liquid>
Two acrylic plates each having a square shape in a plan view and having a length of 10 cm, a width of 10 cm, and a weight of 36 g were prepared. An acrylic plate was placed so that one surface was horizontal, and 49 droplets of 1 μL of the test solution (deionized water) were intermittently placed in a 5 cm square area in the center of the one surface with a pipette. Next, the laminated nonwoven fabric to be measured is placed on the acrylic plate so that the first surface faces the acrylic plate and covers all the droplets on the acrylic plate, and another one is placed on the laminated nonwoven fabric. An acrylic plate was placed. After 60 seconds have passed since the acrylic plate was placed on the laminated nonwoven fabric, the uppermost acrylic plate and the laminated nonwoven fabric below it were removed, and the test solution remaining on the lowermost acrylic plate was weighed (W0 ) was absorbed with one sheet of filter paper (No. 2, manufactured by Toyo Roshi Kaisha, Ltd.), and the weight (W1) of the water absorbing paper was measured with an electronic balance. The weight difference (W1-W0) between the measured value (W1) and the weight of the filter paper before water absorption (W0) was calculated and used as the remaining liquid amount (mg) of the laminated nonwoven fabric. As the amount of remaining liquid is smaller, the laminated nonwoven fabric is evaluated to be more excellent in water absorption performance.

<Method for measuring liquid return amount>
Merries (registered trademark) tape (S size), a disposable diaper manufactured by Kao Corporation that was commercially available in March 2018, was sprayed with cold spray to solidify the adhesive and remove the top sheet. Instead of the removed topsheet, the laminated nonwoven fabrics obtained in Examples and Comparative Examples were reattached to prepare an absorbent article to be measured. The absorbent article to be measured was spread flat and placed horizontally so that the side facing the skin (the side of the top sheet) faced upward. Under this condition, 30 g of artificial urine was injected three times at a flow rate of 5 g/sec under non-pressurized conditions (a total of 90 g injection). Artificial urine was supplied by using a liquid injection pump (manufactured by ISMATEC, MCP-J) by guiding the liquid discharge port to 10 mm above the laminated nonwoven fabric placed on the absorbent with a silicon tube. The 90g supply assumes the average urine volume of an infant. In addition, the supply rate of 5 g/sec is based on the urinary excretion speed of infants. The composition of artificial urine is 1.940% by mass of urea, 0.795% by mass of sodium chloride, 0.111% by mass of magnesium sulfate, 0.062% by mass of calcium chloride, 0.198% by mass of potassium sulfate, Red No. 2 (dye ) 0.005% by weight, water (96.882% by weight) and polyoxyethylene lauryl ether (0.007% by weight), and the surface tension was adjusted to 53±1 dyne/cm (23° C.). A second injection was performed 10 minutes after the first injection. The injection site of the artificial urine was the central portion in the horizontal direction, which was 130 mm apart in the longitudinal direction from the end of the absorber on the ventral side in the longitudinal direction (longitudinal direction). After injecting artificial urine for the third time into the absorbent article, this was left for 10 minutes, after which a collagen film (manufactured by Viscofan Co., CoffiJ) was cut into 7 cm squares and 4 sheets were stacked to form an absorbent article. , and the weight (WC1) of the collagen film was measured with an electronic balance. The weight difference between this weight (WC1) and the weight of the collagen film before absorption (WC0) was calculated (WC1-WC0) and used as the liquid return amount (mg) of the laminated nonwoven fabric.
As the liquid return amount is smaller, the laminated nonwoven fabric is evaluated to be more excellent in water absorption performance.

As shown in Table 1, the laminated nonwoven fabric of each example has: 1) the non-fused portion on the first surface has a lower hydrophilicity than the non-fused portion on the second surface; 3) the non-fused portion has a lower hydrophilicity than the fused portion; The low hydrophilicity region, which is a low unit region, was satisfied, and thus the amount of liquid returning and the amount of remaining liquid were relatively small and were highly evaluated. On the other hand, in Comparative Examples 1 to 4, the contact angle is the same on the first surface of the first region and the first surface of the second region, and the above 3) is not satisfied. 3 and 4 also did not satisfy 2) above, and due to this, the results were inferior to those of the examples.

1 Absorbent article (underpants-type disposable diaper)
F Abdominal part M Inseam part R Back part WF Waist flap 2 Absorbent main body 21 Surface sheet (skin contact sheet)
22 Back sheet 23 Absorbent body 24 Absorbent core 25 Core wrap sheet 3 Exterior body 31 Outer layer sheet 32 Inner layer sheet (skin contact sheet)
4 sweat absorbing sheet (skin contact sheet)
REFERENCE SIGNS LIST 10 laminated nonwoven fabric 10a first surface 10b second surface 11, 12 fiber layers 11F, 12F constituent fibers of fiber layers 13 fused portion 14 non-fused portion 15 unit area 15A high hydrophilicity area 15B low hydrophilicity area X longitudinal direction Y Lateral direction 50A, 50B Laminated nonwoven fabric manufacturing apparatus 520 Engraving roll (compressing means)
5, 5A, 5B, 5C Convex part

Claims (8)

A skin-contacting sheet is disposed so as to be in contact with the wearer's skin when worn, the skin-contacting sheet has a laminated structure of a plurality of fiber layers, and the plurality of fiber layers are fused together to form an integral body. An absorbent article comprising a laminated nonwoven fabric having a fused portion that is softened,
The first surface, which is one surface, and the second surface, which is the other surface, of the laminated nonwoven fabric have the fused portions and non-fused portions in which the plurality of fiber layers are not fused to each other. ,
the non-fused portion of the first surface has a lower hydrophilicity than the non-fused portion of the second surface;
In the first surface, the non-fused portion has a lower hydrophilicity than the fused portion,
When a unit area having a square shape in a plan view of 10 mm square including the fused portion is virtually provided on the first surface, a highly hydrophilic unit area having a relatively high surface hydrophilicity is formed on the first surface. and a low hydrophilicity region, which is a unit region having a relatively low surface hydrophilicity , and the total area of the fused portion is the same between the high hydrophilicity region and the low hydrophilicity region. absorbent article. 2. The absorbent according to claim 1, wherein the hydrophilicity of the single fused portion included in the high hydrophilicity region is higher than the hydrophilicity of the single fused portion included in the low hydrophilicity region. sexual goods. 3. The absorbent according to claim 1 or 2, wherein the area of the single fused portion included in the high hydrophilicity region is larger than the area of the single fused portion included in the low hydrophilicity region. sexual goods. The absorbent according to any one of claims 1 to 3, wherein the number of the fused portions included in the high hydrophilicity region is larger than the number of the fused portions included in the low hydrophilicity region. Goods. The absorbent article according to any one of claims 1 to 4, wherein, on the second surface, the non-fused portion has higher hydrophilicity than the fused portion. The hydrophilicity of the fused portion on one or both of the first surface and the second surface is higher than the hydrophilicity of the non-fused portion on the first surface, and the non-fused portion on the second surface 6. The absorbent article according to claim 5, wherein the hydrophilicity is lower than the hydrophilicity of the fused portion. The absorbent article according to any one of claims 1 to 6, wherein the skin-facing surface of the skin-contacting sheet comprises the first surface of the laminated nonwoven fabric. 8. The absorbent according to any one of claims 1 to 7, comprising a liquid-retaining absorbent and a surface sheet disposed on the skin-facing side of the absorbent, wherein the surface sheet includes the skin-contacting sheet. absorbent article.

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