Absorbent article and method for manufacturing same

Abstract

Provided is an absorbent article which is provided with an absorbent body including an absorbent core of a core covering sheet enclosed in crepe paper, and which is capable of improving back-permeation and suppressing breakage of the core covering sheet by using an improvement in liquid diffusivity in the plane direction in the core covering sheet. An absorbent article (1) is provided with an absorbent body (11). The absorbent body comprises an absorbent core (11a), a skin-side core wrapping sheet (11b1) positioned on the skin side in the thickness direction of the absorbent core, and a non-skin-side core wrapping sheet (11b2) positioned on the non-skin side in the thickness direction of the absorbent core. The skin-side core wrapping sheet and the non-skin-side core wrapping sheet are configured from crepe paper having irregularities. The degree of unevenness of the skin-side core wrapping sheet is smaller than the degree of unevenness of the non-skin-side core wrapping sheet.

Description

Technical Field

[0001] This invention relates to absorbent articles and methods for manufacturing such absorbent articles. Background Technology

[0002] Absorbent articles with absorbent bodies are known, the absorbent body comprising an absorbent core wrapped by a core sheet of crepe paper. For example, Patent Document 1 discloses an absorbent article having an elongated absorbent body, the absorbent body comprising: an absorbent core containing a water-absorbing polymer; an inner sheet disposed on the skin-facing side of the absorbent core; and an outer sheet that completely encloses the absorbent core with the inner sheet disposed thereon. The outer sheet and the inner sheet each carry functional particles of the same type. The liquid penetration rate of the outer sheet is faster than that of the inner sheet. The wrinkling rate of the outer sheet is greater than that of the inner sheet.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-68680 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In Patent Document 1, the absorbent core is enclosed as a whole by an outer sheet, thus the outer sheet is a core-encased sheet. However, the outer sheet has a high wrinkling rate, meaning a greater degree of unevenness (the number and / or size of wrinkles). Therefore, the diffusivity of bodily fluids along the planar direction (hereinafter also referred to as "liquid diffusivity") tends to be low in the outer sheet. In this case, bodily fluids reaching the outer sheet from the surface sheet tend to transfer directly to the absorbent core. Consequently, the absorption of bodily fluids in the absorbent core tends to concentrate in a relatively narrow area of ​​the absorbent body when viewed from above. As a result, there is a concern that the absorbent article is prone to backflow after absorbing bodily fluids.

[0008] To improve liquid diffusion and suppress backflow, it is considered to reduce the wrinkling rate of the outer sheet, i.e., to reduce its unevenness. However, if the unevenness is reduced, the outer sheet becomes difficult to deform. Therefore, there is a concern that during use, the outer sheet may break due to the external force applied to the absorbent material in response to the wearer's movements.

[0009] Therefore, the object of the present invention is to provide an absorbent article and a method for manufacturing the absorbent article, wherein the absorbent article having an absorbent core including an absorbent core wrapped by a core sheet of crepe paper can simultaneously improve rewetting by increasing the planar liquid diffusion in the core sheet and suppress core sheet breakage.

[0010] Solution for solving the problem

[0011] One aspect of the present invention is an absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet. The absorbent body comprises: an absorbent core containing pulp fibers; a skin-side core sheet located on the skin side of the absorbent core in the thickness direction; and a non-skin-side core sheet located on the non-skin side of the absorbent core in the thickness direction. The skin-side core sheet and the non-skin-side core sheet are made of crepe paper with an uneven surface, the unevenness of the skin-side core sheet being less than that of the non-skin-side core sheet.

[0012] Another aspect of the present invention is a method for manufacturing an absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet. The absorbent body includes: an absorbent core comprising pulp fibers; a skin-side core sheet located on the skin side of the absorbent core in the thickness direction; and a non-skin-side core sheet located on the non-skin side of the absorbent core in the thickness direction. The method for manufacturing the absorbent article includes: a preparation step in which a continuous surface sheet formed from the surface sheet is prepared, a continuous skin-side core sheet formed from the skin-side core sheet formed from textured crepe paper, a continuous non-skin-side core sheet formed from the non-skin-side core sheet formed from textured crepe paper, and a plurality of absorbent cores are prepared. The continuous back sheet formed by the continuous back sheet; and a forming process in which a laminate is formed by stacking portions of the continuous surface sheet, portions of the continuous skin-side core packing, the absorbent core, portions of the continuous non-skin-side core packing, and portions of the continuous back sheet in the above-described order, the forming process including a coating process in which at least one of the portions of the continuous surface sheet and the portions of the continuous skin-side core packing is coated with a composition containing a hydrophilic solvent, wherein the unevenness of the portions of the continuous skin-side core packing after the forming process is less than the unevenness of the portions of the continuous non-skin-side core packing.

[0013] The effects of the invention

[0014] According to the present invention, an absorbent article and a method for manufacturing the absorbent article are provided, wherein the absorbent article having an absorbent core including an absorbent core wrapped by a core sheet of crepe paper can simultaneously improve rewetting by increasing the planar liquid diffusion in the core sheet and suppress core sheet breakage. Attached Figure Description

[0015] Figure 1 This is a top view of an example of the structure of a disposable diaper in an unfolded state, illustrating the implementation method.

[0016] Figure 2 This is a bottom view of an example of the structure of a disposable diaper in an unfolded state, illustrating the implementation method.

[0017] Figure 3 It is along Figure 1 A cross-sectional view of the CW-CW line.

[0018] Figure 4 This is a top view showing an example of the structure of the absorber in the embodiment.

[0019] Figure 5 This is a schematic diagram illustrating an example of a method for manufacturing an absorbent article according to an embodiment. Detailed Implementation

[0020] The disclosure of this invention relates to the following methods.

[0021] [Method 1]

[0022] An absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet, wherein the absorbent body comprises: an absorbent core containing pulp fibers; a skin-side core sheet located on the skin side of the absorbent core in the thickness direction; and a non-skin-side core sheet located on the non-skin side of the absorbent core in the thickness direction, the skin-side core sheet and the non-skin-side core sheet being made of crepe paper with an uneven surface, the unevenness of the skin-side core sheet being less than that of the non-skin-side core sheet.

[0023] In this absorbent article, the unevenness (number and / or size of folds) of the skin-side core pack, which is made of textured crease paper, is less than that of the non-skin-side core pack. That is, the unevenness of the skin-side core pack is relatively small. This improves the planar fluid diffusion within the skin-side core pack, thereby increasing the contact area between the surface sheet and the skin-side core pack, as well as the contact area between the skin-side core pack and the absorbent core. Therefore, during use, bodily fluids (including sweat) released into the absorbent article and transferred from the surface sheet to the skin-side core pack can diffuse along the planar direction within the skin-side core pack before transferring to the absorbent core. Consequently, because bodily fluids can be absorbed over a very large area within the absorbent body, the amount of bodily fluid absorbed per unit area when viewed from above is reduced. This makes the absorbent article less prone to backflow after absorbing bodily fluids. On the other hand, by making the non-skin-side core of the crepe paper relatively more textured, it is easier to deform the non-skin-side core. Therefore, during use, even if the absorbent article stretches or contracts due to the wearer's body movement, the non-skin-side core can follow suit, thus preventing breakage. At this time, the texture of the non-skin-side core absorbs the external force generated by body movement, thereby reducing the external force acting on the skin-side core (which has a smaller texture and can withstand less force), and also preventing breakage of the skin-side core. Thus, in absorbent articles having an absorbent core including an absorbent core wrapped in a crepe paper core, it is possible to simultaneously improve backflow by increasing the planar liquid diffusion in the skin-side core and to suppress core breakage.

[0024] [Method 2]

[0025] In the absorbent article described in Method 1, the skin-side core pack comprises: fibers constituting the skin-side core pack; and a composition supported on the fibers, comprising a hydrophilic solvent.

[0026] In this absorbent article, the fibers constituting the skin-side core pack carry a composition containing a hydrophilic solvent (water is also acceptable), thus utilizing the effect of the hydrophilic solvent to facilitate the fibers' affinity for bodily fluids. Therefore, during use, bodily fluids released into the absorbent article and transferred from the surface sheet to the skin-side core pack can further diffuse along the planar direction within the skin-side core pack. That is, the planar fluid diffusivity within the skin-side core pack can be further improved. This further inhibits the backflow of the absorbent article.

[0027] [Method 3]

[0028] In the absorbent article described in Method 2, the composition further comprises a hydrophilic antibacterial agent.

[0029] In this absorbent article, the fibers constituting the skin-side core pack carry a composition also containing a hydrophilic antibacterial agent. Through the effect of the hydrophilic antibacterial agent, the fibers become more readily compatible with bodily fluids. Therefore, during use, bodily fluids released into the absorbent article and transferred from the surface sheet to the skin-side core pack can further diffuse along the planar direction within the skin-side core pack. That is, the planar fluid diffusivity within the skin-side core pack can be further improved. This further inhibits the backflow of the absorbent article. Furthermore, the antibacterial agent can impart antibacterial properties to bodily fluids transferred from the surface sheet to the absorbent body.

[0030] [Method 4]

[0031] In the absorbent article described in Method 3, the solvent comprises a non-volatile organic compound.

[0032] In this absorbent article, the fibers constituting the skin-side core pack carry a solvent containing a hydrophilic and non-volatile organic compound. Through the effect of the hydrophilic and non-volatile organic compound, the affinity between body fluids and fibers is stably and continuously maintained. Therefore, during use, body fluids released into the absorbent article and transferred from the surface sheet to the skin-side core pack can further diffuse along the planar direction within the skin-side core pack. That is, the planar liquid diffusivity within the skin-side core pack can be further improved. This further inhibits the backflow of the absorbent article. Furthermore, because the hydrophilic and non-volatile organic compound is not easily volatilized, it can suppress skin irritation.

[0033] [Method 5]

[0034] In the absorbent article described in any of methods 1 to 4, the unevenness at the central portion in the length direction and the central portion in the width direction of the skin-side core pack is less than the unevenness at the two ends in the length direction and the two ends in the width direction.

[0035] In this absorbent article, the unevenness of the central portion in both the length and width directions of the skin-side core is relatively small (hereinafter also referred to as the "excretion port contact area"). Therefore, the planar fluid diffusion in the excretion port contact area of ​​the skin-side core is relatively large. Consequently, during use, the fluid released into the excretion port contact area can diffuse more rapidly along the planar direction and then transfer to the absorbent core. Therefore, a very large area of ​​the fluid within the absorbent body can be absorbed, thus preventing backflow of the absorbent article. Furthermore, the unevenness of the two ends in both the length and width directions of the skin-side core is relatively large (hereinafter also referred to as the "end areas"). Therefore, the planar fluid diffusion in the end areas of the skin-side core is relatively small. Consequently, during use, the diffusion of fluid from the excretion port contact area outwards can be suppressed in the end areas. Therefore, it can suppress the leakage of bodily fluids from the end area into the outside of the absorbent article during use.

[0036] [Method 6]

[0037] In any of the absorbent articles described in methods 1 to 5, the unevenness of the skin-side core pack is less than the unevenness of the skin-side surface pack.

[0038] In this absorbent article, by making the unevenness of the skin-side core pocket smaller than that of the skin-side surface piece, it is easier for the skin-side core pocket to come into contact with the surface piece. Therefore, during use, bodily fluids released onto the surface piece can rapidly transfer from the surface piece to the skin-side core pocket, and can then diffuse along the planar direction within the skin-side core pocket before transferring to the absorbent core. Furthermore, by making the unevenness of the skin-side surface piece relatively larger, bodily fluids absorbed by the absorbent core are less likely to come into contact with the wearer's skin via the surface piece, thus reducing the likelihood of backflow.

[0039] [Method 7]

[0040] In any of the absorbent articles described in methods 1 to 6, for the crepe paper in the skin-side core pack and the crepe paper in the non-skin-side core pack, the surface opposite to the convex portion of the concavity is formed as concave, and the concave portion includes a portion of the pulp fibers of the absorbent core.

[0041] In this absorbent article, a portion of the pulp fibers of the absorbent core are contained in the concave portion of the crease paper in the skin-side core pack, opposite to the convex portion. This allows for a larger contact area between the skin-side core pack and the absorbent core. Consequently, during use, bodily fluids drained into the absorbent article can be rapidly transferred from the skin-side core pack to the absorbent core. Furthermore, in the crease paper of the non-skin-side core pack, a portion of the pulp fibers of the absorbent core are contained in the concave portion of the crease paper, opposite to the convex portion. This allows bodily fluids that are not fully absorbed by the absorbent core to easily diffuse in the planar direction and be absorbed by the absorbent core at its ends in the length and / or width directions. Moreover, the presence of pulp fibers in the concave portion of the opposite side of the convex portion helps prevent excessive deformation of both the skin-side and non-skin-side core packs, which could lead to a decrease in absorbency.

[0042] [Method 8]

[0043] In any of the absorbent articles described in methods 1 to 7, a non-skin-side elastic member extending along the length direction is provided at a position that overlaps with the absorbent in the thickness direction and is located on the non-skin side of the absorbent in the thickness direction.

[0044] In this absorbent article, a non-skin-side elastic member extending along its length is provided at a position overlapping the absorbent body in the thickness direction and on the non-skin side of the absorbent body in the thickness direction. This allows the skin-side portion of the absorbent body to be easily pressed against the body. Consequently, during use, bodily fluids released into the absorbent article can be transferred more rapidly from the surface sheet to the absorbent body. Furthermore, the non-skin-side elastic member can reinforce the non-skin-side core packing, thereby further suppressing breakage of the non-skin-side core packing.

[0045] [Method 9]

[0046] The absorbent article described in Method 8 further comprises a pair of leak-proof walls located on both sides of the surface sheet in the width direction and extending along the length direction. Each pair of leak-proof walls includes a leak-proof elastic member extending along the length direction, wherein the contractile force per unit length of the leak-proof elastic member is smaller than the contractile force per unit length of the non-skin-side elastic member.

[0047] In this absorbent article, each of the pair of leak-proof walls located on both sides of the surface sheet in the width direction and extending along the length direction is further provided with a leak-proof elastic member extending along the length direction, thereby suppressing side leakage of bodily fluids in the width direction. Furthermore, since the non-skin side elastic member has a contractile force per unit length greater than that of the leak-proof elastic member, it is easier to press the skin side portion of the absorbent onto the body. Therefore, during use, side leakage of bodily fluids released into the absorbent article can be suppressed, and the bodily fluids can be transferred more rapidly from the surface sheet to the absorbent.

[0048] [Method 10]

[0049] In any of the absorbent articles described in methods 1 to 9, there is a pair of embossed portions formed as grooves extending from the surface of the surface sheet toward the absorbent body and along the length direction, wherein the unevenness in the region between the pair of embossed portions of the skin-side core sheet is less than the unevenness in the region of the skin-side core sheet located outside the width direction of each of the embossed portions of the pair of embossed portions.

[0050] In this absorbent article, a pair of embossed portions extending along the length direction are provided, and the unevenness in the region between the pair of embossed portions of the skin-side core pack (hereinafter also referred to as the "inner region") is relatively small. Therefore, the planar liquid diffusion in the inner region of the skin-side core pack is relatively large. Consequently, in the skin-side core pack, during use, bodily fluid released into the inner region can diffuse more rapidly along the planar direction and then transfer to the absorbent core. Therefore, a very large area of ​​bodily fluid within the absorbent body can be absorbed, thereby preventing backflow of the absorbent article. Furthermore, the unevenness in the region of the skin-side core pack located on the outer side of the width direction of each of the pair of embossed portions (hereinafter also referred to as the "outer region") is relatively large. Therefore, the planar liquid diffusion in the outer region of the skin-side core pack is relatively small. Therefore, during use, the diffusion of bodily fluids from the inner region outwards (across the embossed portion) can be suppressed in the outer region, and the bodily fluids can be transferred to the absorbent core. Thus, leakage of bodily fluids from the outer region to the outside of the absorbent article during use can be suppressed.

[0051] [Method 11]

[0052] A method for manufacturing an absorbent article, the absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet, the absorbent body comprising: an absorbent core containing pulp fibers; a skin-side core sheet located on the skin side of the absorbent core in the thickness direction; and a non-skin-side core sheet located on the non-skin side of the absorbent core in the thickness direction, wherein the method for manufacturing the absorbent article comprises: a preparation step, in which a continuous surface sheet formed by the continuous surface sheet, a continuous skin-side core sheet formed by the continuous skin-side core sheet formed by the continuous skin-side core sheet formed by the continuous skin-side core sheet formed by the continuous skin-side core sheet formed by the continuous non-skin ..., a plurality of the absorbent cores, and a... The document describes a continuous back sheet formed by continuously forming a back sheet; and a forming process in which a laminate is formed by stacking portions of the continuous surface sheet, portions of the continuous skin-side core packing, the absorbent core, portions of the continuous non-skin-side core packing, and portions of the continuous back sheet in the above-described order, the forming process including a coating process in which at least one of the portions of the continuous surface sheet and the portions of the continuous skin-side core packing is coated with a composition containing a hydrophilic solvent, wherein the unevenness of the portions of the continuous skin-side core packing after the forming process is less than the unevenness of the portions of the continuous non-skin-side core packing.

[0053] In this method of manufacturing an absorbent article, the composition coated on a surface sheet and transferred to a skin-side core pack in contact with the surface sheet, or the composition coated on the skin-side core pack, can be used to make the skin-side core pack relatively less uneven. Therefore, the contact area between the surface sheet and the skin-side core pack can be larger. This improves the stability of the bond between the surface sheet and the skin-side core pack. Simultaneously, because the skin-side core pack of the manufactured absorbent article has a relatively small unevenness, during use, bodily fluids (including sweat) released into the absorbent article and transferred from the surface sheet to the skin-side core pack can diffuse along the planar direction of the skin-side core pack and then transfer to the absorbent core. Therefore, since bodily fluids can be absorbed over a very large area within the absorbent body, the amount of bodily fluid absorbed per unit area when viewed from above is reduced. This makes the absorbent article less prone to backflow after absorbing bodily fluids. In addition, by making the non-skin side core of the crepe paper relatively more uneven, it is easier to deform the non-skin side core, thereby preventing the non-skin side core and skin side core from breaking during use.

[0054] [Method 12]

[0055] In the method described in Method 11, during the coating step, the composition is coated on at least one of the central portions in the length direction and the central portions in the width direction of the portion of the surface sheet in the continuous surface sheet, and the central portions in the length direction and the central portions in the width direction of the portion of the skin-side core pack in the continuous skin-side core pack.

[0056] In this method of manufacturing an absorbent article, the composition is applied to the central portion in both the length and width directions of the surface sheet or skin-side core pack, i.e., the discharge port contact area. This reduces the degree of unevenness in the skin-side core pack. Consequently, the contact area between the surface sheet and the skin-side core pack in the discharge port contact area can be further increased. This further improves the bonding stability between the surface sheet and the skin-side core pack in the discharge port contact area. Furthermore, the composition is not applied to the ends of the surface sheet or skin-side core pack other than the central portion in both the length and width directions. By not applying the composition to the ends in both the length and width directions where the adhesive is primarily applied when the sheets are joined together, the adhesive can function properly at the ends. This prevents obstacles such as sheet curling at the ends of the absorbent article caused by the adhesive failing to function properly during transport.

[0057] [Method 13]

[0058] In the method described in mode 11 or mode 12, during the coating step, the composition, when viewed from above, is coated on at least one of the regions in the continuous surface sheet where the absorbent core is disposed, and the regions in the continuous skin-side core sheet where the absorbent core is disposed.

[0059] In this method of manufacturing an absorbent article, when viewed from above, the composition is applied only to the area where the absorbent core is disposed within the surface sheet or skin-side core pack. By limiting the area where the composition is applied, even when the skin-side core pack and non-skin-side core pack are joined outside the area where the absorbent core is disposed, diffusion of the composition from the skin-side core pack to the non-skin-side core pack can be suppressed. This prevents the non-skin-side core pack from becoming less smooth and the adhesive from failing to function properly when the sheets are joined together.

[0060] [Method 14]

[0061] In any of the methods described in methods 11 to 13, the composition further comprises a hydrophilic antibacterial agent, and the solvent comprises water and an organic solvent, wherein the amount of water is less than the amount of the organic solvent.

[0062] In the manufacturing method of this absorbent article, the composition further includes a hydrophilic antibacterial agent, and the solvent includes water and an organic solvent, with the amount of water being less than the amount of organic solvent. Thus, by reducing the water ratio in the composition, rust formation in the manufacturing apparatus can be suppressed. On the other hand, by increasing the organic solvent ratio in the composition, the possibility of the antibacterial agent itself being exposed on the surface of the surface sheet and irritating the wearer's skin can be suppressed.

[0063] Hereinafter, the absorbent article of the embodiment and the method of manufacturing the absorbent article will be described using a shorts-type disposable diaper (hereinafter also simply referred to as "disposable diaper") as an example. However, the type of absorbent article is not limited to this example, and other types of absorbent articles may be used as long as they do not depart from the scope of the present invention. Examples of such absorbent articles include band-type diapers, incontinence pads, sanitary napkins, and panty liners.

[0064] First, the absorbent article of the embodiment will be described. Figures 1-4 This is a diagram illustrating a structural example of the disposable diaper 1 according to an embodiment. Figure 1 This is a top view of an example of the structure of a disposable diaper in its unfolded state, illustrating an embodiment of the invention. Figure 2 This is a bottom view showing the unfolded state of a structural example of a disposable diaper according to an embodiment. Figure 3 It is along Figure 1 A schematic cross-sectional view of the CW-CW line. Figure 4 This is a top view showing an example of the structure of the absorber in the embodiment.

[0065] For disposable diaper 1, in Figure 1In the unfolded state shown, there are mutually orthogonal length directions L, width directions W, and thickness directions T, and a length direction centerline CL that passes through the center of the width direction W and extends along the length direction L, and a width direction centerline CW that passes through the center of the length direction L and extends along the width direction W. Here, the orientation close to the length direction centerline CL is defined as the inward orientation of the width direction W, the side close to the length direction centerline CL is defined as the inner side of the width direction W, the orientation away from the length direction centerline CL is defined as the outward orientation of the width direction W, and the side away from the length direction centerline CL is defined as the outer side of the width direction W. On the other hand, the orientation close to the width direction centerline CW is defined as the inward orientation of the length direction L, the side close to the width direction centerline CW is defined as the inner side of the length direction L, the orientation away from the width direction centerline CW is defined as the outward orientation of the length direction L, and the side away from the width direction centerline CW is defined as the outer side of the length direction L. Furthermore, the side of the disposable diaper 1 facing the abdomen of the wearer in the length direction L (the ventral edge) is called the front side in the length direction L, and the side of the disposable diaper 1 facing the back of the wearer in the length direction L (the dorsal edge) is called the rear side in the length direction L. Additionally, "top view" refers to the observation of the disposable diaper 1 unfolded in a planar state including the length direction L and the width direction W from above in the thickness direction T; "top view shape" refers to the shape observed during top view. "Planar direction" refers to any direction parallel to the plane including the width direction W and the length direction L. "Skin side" refers to the side of the disposable diaper 1 that is relatively close to the wearer's skin in the thickness direction T when worn by the wearer; "non-skin side" refers to the side of the disposable diaper 1 that is relatively far from the wearer's skin in the thickness direction T when worn by the wearer. A direction along the length direction L is not limited to being parallel to the length direction L, but includes a range of ±30° relative to the length direction L. A direction along the width direction W means, not limited to the case of being parallel to the width direction W, but including a range of ±30° relative to the width direction W. This definition applies not only to disposable diapers 1, but also to the absorbent body of disposable diapers 1 and the various materials in which they are configured.

[0066] like Figure 1 As shown, in a disposable diaper 1, a ventral portion (ventral waistband) 2 located at the front, a dorsal portion (dorsal waistband) 3 located at the rear, and an absorbent body 10 located between the ventral portion 2 and the dorsal portion 3 are provided along the length direction L. In this embodiment, the ventral portion 2 has a rectangular shape that extends substantially along the width direction W, the dorsal portion 3 has a rectangular shape that extends substantially along the width direction W, but has a portion at the front in the length direction L that extends forward, and the absorbent body 10 has a rectangular shape that extends substantially along the length direction L.

[0067] The ventral portion 2 is the part that abuts against the wearer's abdomen. The dorsal portion 3 is the part that abuts against the wearer's buttocks or back. The absorbent body 10 is the part that abuts against the wearer's groin (excretion opening). One end of the absorbent body 10 in the longitudinal direction L is overlapped and joined to the skin-side surface of the ventral portion 2, and the other end of the absorbent body 10 in the longitudinal direction L is overlapped and joined to the skin-side surface of the dorsal portion 3. The two ends 2a, 2a in the width direction W of the ventral portion 2 and the two ends 3a, 3a in the width direction W of the dorsal portion 3 overlap in the thickness direction T and are joined along the length direction L, thereby forming a disposable diaper 1. In this case, in the disposable diaper 1, the waist opening for the wearer's waist to pass through is defined by the outer ends in the longitudinal direction L of the ventral portion 2 and the outer ends in the longitudinal direction L of the dorsal portion 3. In addition, in the disposable diaper 1, a pair of leg openings for the wearer's legs to pass through are defined by the two ends of the absorbent body 10 in the width direction W, the inner end of the abdominal side 2 in the length direction L, and the inner end of the dorsal side 3 in the length direction L.

[0068] In this embodiment, Figure 1 In the illustrated state, the ventral portion 2 and the dorsal portion 3 are separated from each other in the length direction L. That is, the ventral portion 2 and the dorsal portion 3 are formed separately. Furthermore, in another embodiment, the disposable diaper 1 also includes a crotch portion located between the ventral portion 2 and the dorsal portion 3, with one end connected to the ventral portion 2 and the other end connected to the dorsal portion 3. In this case, the ventral portion 2, the dorsal portion 3, and the crotch portion are formed integrally or separately.

[0069] In this embodiment, the ventral portion 2 has liquid-impermeable cover sheets 21, 22, and 24. Cover sheet 21 is located on the skin side, and cover sheet 22 is located on the non-skin side. Cover sheets 21 and 22 are stacked in the thickness direction T and bonded together using an adhesive or heat fusion. Cover sheet 24 is stacked on cover sheet 21 to cover the front end of the absorbent body 10 in the length direction L from the skin side. Similarly, in this embodiment, the dorsal portion 3 has liquid-impermeable cover sheets 31, 32, and 34. Cover sheet 31 is located on the skin side, and cover sheet 32 ​​is located on the non-skin side. Cover sheets 31 and 32 are stacked in the thickness direction T and bonded together using an adhesive or heat fusion. Cover sheet 34 is stacked on cover sheet 31 to cover the rear end of the absorbent body 10 in the length direction L from the skin side. Examples of materials for each cover sheet include liquid-impermeable nonwoven fabrics and synthetic resin films. The types of liquid-impermeable nonwoven fabrics and synthetic resin films, and their materials, will be described later. Furthermore, at least one of the cover sheets 24 and 34 may be omitted. Each cover sheet may also consist of multiple sheets.

[0070] In this embodiment, in the ventral portion 2, a plurality of elastic members 23 for waist pleats are provided between the cover sheet 21 and the cover sheet 22. The plurality of elastic members 23 extend along the width direction W and are spaced apart in the length direction L in the ventral portion 2, and are joined to the cover sheet 21 and the cover sheet 22 by adhesive or heat fusion. Alternatively, the elastic members 23 may be provided in a region of the absorbent body 10 that is not in the ventral portion 2 but on the non-skin side. Similarly, in this embodiment, in the dorsal portion 3, a plurality of elastic members 33 for waist pleats are provided between the cover sheet 31 and the cover sheet 32. The plurality of elastic members 33 extend along the width direction W and are spaced apart in the length direction L in the dorsal portion 3, and are joined to the cover sheet 31 and the cover sheet 32 ​​by adhesive or heat fusion. Alternatively, the elastic members 33 may be provided in a region of the absorbent body 10 that is not in the dorsal portion 3 but on the non-skin side. In this embodiment, the back side portion 3 also has a plurality of elastic members 35 for leg pleats between the cover sheet 31 and the cover sheet 32. The plurality of elastic members 35 are configured to protrude toward the ventral side portion 2 when viewed from above, on the inner side of the elastic member 33 in the longitudinal direction L. Elastic bands can be exemplified as the material of each elastic member.

[0071] In this embodiment, the absorbent body 10 includes a liquid-permeable surface sheet 12, a liquid-impermeable back sheet 13, and an absorbent body 11 located between the surface sheet 12 and the back sheet 13, which absorbs and retains liquid. Examples of materials for the surface sheet 12 include liquid-permeable nonwoven fabrics, woven fabrics, synthetic resin films with liquid-permeable pores, and combinations of similar or different types thereof. Examples of materials for the back sheet 13 include liquid-impermeable and air-permeable nonwoven fabrics, synthetic resin films with air-permeable pores, and combinations of similar or different types thereof. Furthermore, a liquid-permeable diffusion sheet may be provided between the surface sheet 12 and the absorbent body 11, which allows liquid to diffuse in a planar direction.

[0072] As the surface sheet 12, examples include a flat sheet without any bumps or depressions, a sheet having a plurality of protrusions that extend along the length direction L and are arranged at intervals in the width direction W and a plurality of recesses provided between each of the protrusions, and a sheet in which the plurality of protrusions are generally circular when viewed from above and are arranged in a checkered pattern when viewed from above.

[0073] There are no particular restrictions on the types of nonwoven fabrics, whether they are permeable or impermeable to liquid, as long as they can be used as absorbent materials. Examples include meltblown nonwoven fabrics, spunbond nonwoven fabrics, air-laid nonwoven fabrics, and hot-air nonwoven fabrics. There are no particular restrictions on the materials used in nonwoven fabrics, as long as they can be used as absorbent materials. Examples include synthetic resin fibers and pulp fibers. There are no particular restrictions on the synthetic resins used, as long as they can be used as absorbent materials. Examples include olefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate. Pulp fibers will be discussed later. There are no particular restrictions on the types of synthetic resin films, whether they are permeable or impermeable to liquid, as long as they can be used as absorbent materials. There are no particular restrictions on the materials used in synthetic resin films, as long as they can be used as absorbent materials. Examples include the aforementioned synthetic resins.

[0074] The absorbent 11 includes an absorbent core 11a that absorbs and retains liquid, and a core sheet 11b enclosing the absorbent core 11a. Examples of absorbent core 11a materials include absorbent materials such as pulp fibers and superabsorbent polymers. Examples of pulp fibers include cellulose fibers. Examples of cellulose fibers include wood pulp, cross-linked pulp, non-wood pulp, regenerated cellulose, and semi-synthetic cellulose. Examples of superabsorbent polymers (SAP) include polyacrylates, polysulfonates, and maleic anhydride salts. Examples of core sheet 11b materials include, for example, liquid-permeable nonwoven fabrics (including tissue paper) formed from synthetic resin fibers or pulp fibers, and composite sheets thereof. There are no particular limitations on the type of synthetic resin fiber, as long as it can be used as an absorbent article; known synthetic fibers can be cited. The types of nonwoven fabrics, synthetic resins, and pulp fibers are as described above. Details of absorber 11 will be described later.

[0075] The absorbent body 11 and the surface sheet 12, as well as the absorbent body 11 and the back sheet 13, are bonded together using an adhesive. The surface sheet 12 and the back sheet 13 are bonded together at their peripheral portions using an adhesive. Examples of adhesives include hot melt adhesives. Furthermore, the shape of the absorbent body 10 is not limited to the above examples as long as it is longer in the length direction L; examples include rounded rectangles, rectangles with convex curves on the shorter sides, and hourglass shapes.

[0076] The unit area weight of the surface sheet 12, back sheet 13, and absorbent body 11 can be appropriately adjusted according to the required absorbency of the disposable diaper 1, but there are no particular restrictions as long as it can be used as a sheet material for the disposable diaper 1. For example, a unit area weight of 5 g / m² can be given for the surface sheet 12. 2 ~200g / m 2 As for the weight per unit area of ​​the back sheet 13, for example, it can be 5g / m². 2 ~200g / m 2 The weight per unit area of ​​the absorbent core 11a can be, for example, 10 g / m². 2 ~2000g / m 2 As for the unit area weight of the core sheet 11b, for example, 5 g / m² can be cited. 2 ~100g / m 2 .

[0077] The average fiber diameter of the fibers constituting the core sheet 11b is not particularly limited as long as it can be used as a sheet material for disposable diapers 1. Examples of the average fiber diameter are 5 μm to 100 μm, preferably 10 μm to 50 μm. By setting the average fiber diameter to 5 μm or more, the fibers are not made too thin, which prevents the liquid composition coated on the core sheet 11b from easily moving (or falling) vertically downwards due to gravity. By setting the average fiber diameter to 100 μm or less, the fibers are not made too thick, which allows for a larger surface area per unit volume of the fibers, making it easier to retain a larger liquid composition.

[0078] In this embodiment, the absorbent body 10 further includes an outer sheet 14 laminated on the non-skin side of the back sheet 13. In the outer sheet 14, portions on both sides in the width direction W wrap around to the skin side of the laminate of the surface sheet 12, absorbent body 11, and back sheet 13, forming a pair of leak-proof walls 15 extending in the length direction L. In each leak-proof wall 15, the outer edge in the width direction W is fixed to the end edge in the width direction W of the absorbent body 10, while the inner edge in the width direction W is not fixed. The two ends in the length direction L of the leak-proof wall 15 are covered and fixed by cover sheets 24 and 34. For example, hydrophobic sheets such as hydrophobic nonwoven fabric can be used as materials for the outer sheet 14 and the leak-proof walls 15. In another embodiment, for example, hydrophilic sheets such as hydrophilic nonwoven fabric can be used as materials for the outer sheet 14 and the leak-proof walls 15. Each leak-proof wall 15 includes two leak-proof elastic members 16 extending along the length direction L at its inner end in the width direction W. The leak-proof elastic members 16 are exemplified as elastic bands. In another embodiment, in each of a pair of leak-proof walls 15, the inner end in the width direction W is further folded back outward in the width direction W. In another embodiment, there is one or more leak-proof elastic members 16.

[0079] In this embodiment, the absorbent body 10 also includes one or more non-skin-side elastic members 17 and one or more non-skin-side elastic members 18 at a position overlapping the absorbent body 11 in the thickness direction T, between the back panel 13 and the outer panel 14. The non-skin-side elastic members 17 extend along the length direction L at both ends in the width direction W of the absorbent body 10. The non-skin-side elastic members 17 are used for leg pleats. On the other hand, the non-skin-side elastic members 18 extend along the length direction L from the center in the width direction W and the rear end in the length direction L of the absorbent body 10 to near the center. The non-skin-side elastic members 18 are used to press the rear (back) portion of the absorbent body 10 in the length direction L against the wearer's buttocks or back. Elastic bands can be used as the material for each non-skin-side elastic member.

[0080] Next, the absorber 11 will be described. The absorber 11 is a layer having both liquid absorption and liquid retention properties. In this embodiment, the absorber 11 has a single-layer structure. Furthermore, in another embodiment, the absorber 11 has a double-layer structure having an upper layer and a lower layer. In this case, the lengths of the upper layer in the width direction W and the lower layer in the width direction W can be the same or different, the lengths of the upper layer in the length direction L and the lower layer in the length direction L can be the same or different, and the amount and type of absorbent material can also be different. In another embodiment, the absorber 11 has a multi-layer structure having three or more layers.

[0081] The shape of the absorber 11 (and the core sheet 11b) when viewed from above is not particularly limited as long as it extends along the length direction L. In this embodiment, the absorber 11 (and the core sheet 11b) has a rectangular shape extending along the length direction L. However, its shape is not limited to this example; for example, a rectangle with a short side protruding in an arc shape, a rectangle with rounded corners, an ellipse, or an hourglass shape can be included. The length (thickness) of the absorber 11 in the thickness direction T can be, for example, 0.5 mm to 20 mm, the length (length) of the absorber 11 in the length direction L can be, for example, 15 cm to 40 cm, and the length (width) of the absorber 11 in the width direction W can be, for example, 5 cm to 15 cm.

[0082] The shape of the absorbent core 11a when viewed from above is an extension along the length direction L, and there are no particular limitations as long as it can be accommodated in the core sheet 11b. In this embodiment, the absorbent 11 has a generally hourglass shape that narrows inward from the center in the length direction L. However, its shape is not limited to this example, and examples include a rectangle with a short side protruding in an arc shape, a rectangle with rounded corners, and an ellipse.

[0083] The core sheet 11b includes a skin-side core sheet 11b1 disposed on the skin side in the thickness direction T of the absorbent core 11a, and a non-skin-side core sheet 11b2 disposed on the non-skin side in the thickness direction T of the absorbent core 11a. In this embodiment, the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 are integrally formed, i.e., formed from a single sheet. Furthermore, the two ends of the sheet in the width direction W are joined together to form a cylindrical shape, inside which the absorbent core 11a is enclosed, and the two ends in the length direction L are sealed, thereby constituting the absorbent body 11. In this case, the core sheet that is half the size (thickness) of the absorbent core 11a in the thickness direction T and is located on the skin side is designated as the skin-side core sheet 11b1, and the core sheet that is half the size (thickness) of the absorbent core 11a in the thickness direction T and is located on the non-skin side is designated as the non-skin-side core sheet 11b2. In another embodiment, the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 are formed separately from each other. Furthermore, in another embodiment, at least one of the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 is formed from a plurality of sheets.

[0084] Both the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 are made of crepe paper. The crepe paper is a nonwoven fabric (including paper) formed from synthetic resin fibers or pulp fibers, etc., that has undergone a creping process, and has an uneven structure with concave and convex portions composed of multiple folds. Furthermore, the unevenness of the skin-side core sheet 11b1 is less than that of the non-skin-side core sheet 11b2. Here, the unevenness refers to the number and / or size of the folds per unit length in a direction perpendicular to the extension direction (e.g., length direction L) of the folds. Figure 3 As shown in (b), the size of the irregularity refers to the height H and / or width D of the irregularity. The height H refers to the height from the bottom of the recess (the portion between adjacent protrusions 51) to the top of the protrusion 51. The width D refers to the distance between the tops of adjacent protrusions 51 or the distance between the bottoms of adjacent recesses. A smaller degree of irregularity refers to a smaller number of irregularities, a lower height H, and / or a larger width D, excluding cases where there are no irregularities. This is to maintain the deformability of the absorbent 11 on the skin side to a certain extent. Furthermore, the method for measuring the degree of irregularity of the core sheet will be described later.

[0085] Furthermore, the texture of crepe paper can be adjusted by the crepe processing conditions and the application of liquid to the crepe paper. For example, when liquid is applied to crepe paper, the coated area becomes soft due to the liquid immersion, and the texture easily flattens out. This results in a smaller texture. In this case, from the viewpoint of easily maintaining affinity with bodily fluids and the desired texture, a hydrophilic and non-volatile liquid is preferred as the liquid applied to the crepe paper.

[0086] In this embodiment, in terms of the degree of unevenness, it is not necessary for the skin-side core piece 11b1 to be smaller than the non-skin-side core piece 11b2 throughout the entire surface. Examples of parts with a smaller degree of unevenness include, when viewed from above, the central portion (1 part) excluding the two ends (1 part each) of the entire surface of the skin-side core piece 11b1, when the skin-side core piece 11b1 is divided into 3 parts in the width direction W; the central portions (two parts) excluding the two ends (1 part each) of the skin-side core piece 11b1, when the skin-side core piece 11b1 is divided into 4 parts in the width direction W; and the central portions (3 or 1 parts) excluding the two ends (1 or 2 parts each) of the skin-side core piece 11b1, when the skin-side core piece 11b1 is divided into 5 parts in the width direction W. And / or, as a part with a smaller degree of unevenness as described above, examples include, when viewed from above, the central portion (1) other than the two ends (1 each) of the entire surface of the skin-side core package 11b1, for example, when the skin-side core package 11b1 is divided into 3 parts in the length direction L, the central portion (2) other than the two ends (1 each) of the skin-side core package 11b1 is divided into 4 parts in the length direction L, and the central portion (3) other than the two ends (1 each) of the skin-side core package 11b1 is divided into 5 parts in the length direction L.

[0087] In another embodiment, as the part with less unevenness described above, a portion of more than 20% of the entire surface of the skin-side core pack 11b1 when viewed from above can be taken as an example, including the center in the length direction L and the center in the width direction W (the intersection of the center line CL in the length direction and the center line CW in the width direction), and preferably a portion of more than 40% of the area including the aforementioned centers, and more preferably a portion of more than 60% of the area including the aforementioned centers.

[0088] In any of the above cases, the portion with less unevenness preferably includes the discharge port contact area when viewed from above, and is preferably the area overlapping with the absorbent core 11a. Furthermore, the discharge port contact area refers to the area that faces or contacts the wearer's discharge port when using the absorbent article (including disposable diapers 1). The discharge port contact area can be appropriately set according to the type and purpose of the absorbent article. For example, the discharge port contact area is set in the length direction L at the center of the absorbent body or slightly in front of the center, with a length of approximately 1 / 10 to 1 / 2 of the total length of the absorbent body, and in the width direction W at approximately the center of the absorbent body, with a width of approximately 1 / 3 to 1 / 2 of the total width of the absorbent body.

[0089] In this embodiment, the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 enclose the absorbent core 11a in such a way that the creases and wrinkles of their crease paper extend along the length direction L. However, each core sheet 11b1 and the non-skin-side core sheet 11b2 does not need to have creases or wrinkles on its entire surface. It is sufficient that creases and wrinkles are present in at least 90% of the entire surface of each core sheet 11b1 and the non-skin-side core sheet 11b2, preferably at least 95% of the area including the area where the discharge port abuts, and more preferably at least 98% of the area including the area where the discharge port abuts. As a result, breakage caused by external forces can be easily suppressed in each core sheet 11b1 and the non-skin-side core sheet 11b2.

[0090] In the disposable diaper 1 described above, the degree of unevenness (number and / or size of the unevenness) of the skin-side core pack 11b1, which is made of textured paper, is less than that of the non-skin-side core pack 11b2. That is, the degree of unevenness of the skin-side core pack 11b1 is relatively small in the disposable diaper 1. As a result, the liquid diffusivity in the planar direction of the skin-side core pack 11b1 can be improved, thereby increasing the contact area between the surface sheet 12 and the skin-side core pack 11b1, as well as the contact area between the skin-side core pack 11b1 and the absorbent core 11a. Therefore, during use, bodily fluids (including sweat) released into the disposable diaper 1 and transferred from the surface sheet 12 to the skin-side core pack 11b1 can diffuse along the planar direction of the skin-side core pack 11b1 and then transfer to the absorbent core 11a. Therefore, because it can absorb bodily fluids over a very large area within the absorbent body 11, the amount of bodily fluid absorbed per unit area when viewed from above is reduced. This makes it less prone to backflow after the disposable diaper 1 has absorbed bodily fluids.

[0091] On the other hand, by making the non-skin side core piece 11b2 of the crepe paper relatively large, it is easier to deform the non-skin side core piece 11b2. Therefore, during use, even if the disposable diaper 1 stretches or contracts due to the wearer's body movement, the non-skin side core piece 11b2 can follow the stretching and contraction, thus suppressing breakage. At this time, the unevenness of the non-skin side core piece 11b2 absorbs the external force generated by body movement, thus reducing the external force acting on the skin side core piece 11b1 (which has a smaller unevenness and can withstand relatively small external forces), and also suppressing breakage of the skin side core piece 11b1.

[0092] In this way, in a disposable diaper 1 having an absorbent core 11a wrapped by a core sheet 11b of crepe paper, it is possible to improve backflow by increasing the planar liquid diffusion in the core sheet 11b1 on the skin side and to suppress breakage of the core sheet 11b.

[0093] In this embodiment, the number of protrusions per unit length in the skin-side core sheet 11b1 in the direction perpendicular to the direction of extension of the protrusions (folds), i.e., the number of protrusions extending along the length direction L per 1 cm unit length in the width direction W (on average), can be 1 to 50. By having more than 1 protrusion, the skin-side core sheet 11b1 can be easily deformed, and breakage of the skin-side core sheet 11b1 can be suppressed. By having fewer than 50 protrusions, the liquid diffusivity in the planar direction of the skin-side core sheet 11b1 can be improved, and the contact area between the skin-side core sheet 11b1 and the surface sheet 12, as well as the contact area between the skin-side core sheet 11b1 and the absorbent core 11a, can be larger.

[0094] In this embodiment, the average height H of the unevenness (folds) in the skin-side core piece 11b1 can be, for example, 0.1 mm to 1 mm. By making the height H of the unevenness 0.1 mm or more, the skin-side core piece 11b1 can be easily deformed, and breakage of the skin-side core piece 11b1 can be suppressed. By making the height H of the unevenness 1 mm or less, the liquid diffusivity in the planar direction of the skin-side core piece 11b1 can be improved, and the contact area between the skin-side core piece 11b1 and the surface sheet 12, as well as the contact area between the skin-side core piece 11b1 and the absorbent core 11a, can be larger. In addition, the average width D of the unevenness can be, for example, 0.2 mm to 10 mm. By making the width D of the unevenness 0.2 mm or more, the skin-side core piece 11b1 can be easily deformed, and breakage of the skin-side core piece 11b1 can be suppressed. By making the width D of the uneven surface less than 10 mm, the liquid diffusion in the planar direction of the skin-side core pack 11b1 can be improved, and the contact area between the skin-side core pack 11b1 and the surface sheet 12, as well as the contact area between the skin-side core pack 11b1 and the absorbent core 11a, can be larger.

[0095] In this embodiment, the number (on average) of the irregularities (folds) extending along the length direction L per 1 cm unit length in the width direction W of the non-skin side core sheet 11b2 can be, for example, 2 to 100. By having two or more irregularities, the non-skin side core sheet 11b2 can be easily deformed, and breakage of both the non-skin side core sheet 11b2 and the skin side core sheet 11b1 can be suppressed. By having fewer than 100 irregularities, the liquid diffusivity in the planar direction of the non-skin side core sheet 11b2 can be improved to a certain extent, and the contact area between the non-skin side core sheet 11b2 and the back sheet 13, as well as the contact area between the non-skin side core sheet 11b2 and the absorbent core 11a, can be larger.

[0096] In this embodiment, the height (average) of the unevenness (wrinkles) in the non-skin side core sheet 11b2, which is the size of the unevenness, can be, for example, 0.2 mm to 2 mm. By making the height H of the unevenness 0.2 mm or more, the non-skin side core sheet 11b2 can be easily deformed, and the breakage of the non-skin side core sheet 11b2 and the skin side core sheet 11b1 can be suppressed. By making the height H of the unevenness 6 mm or less, the liquid diffusion in the planar direction of the non-skin side core sheet 11b2 can be improved to a certain extent, and the contact area between the non-skin side core sheet 11b2 and the back sheet 13, as well as the contact area between the non-skin side core sheet 11b2 and the absorbent core 11a, can be larger. In addition, the width D (average) of the unevenness, which is the size of the unevenness, can be, for example, 0.1 mm to 5 mm. By making the width D of the uneven surface 0.1 mm or more, the non-skin side core sheet 11b2 can be easily deformed, and the breakage of both the non-skin side core sheet 11b2 and the skin side core sheet 11b1 can be suppressed. By making the width D of the uneven surface 5 mm or less, the liquid diffusion in the planar direction of the non-skin side core sheet 11b2 can be improved to a certain extent, and the contact area between the non-skin side core sheet 11b2 and the back sheet 13, as well as the contact area between the non-skin side core sheet 11b2 and the absorbent core 11a, can be larger.

[0097] In a preferred embodiment of this invention, the skin-side core pack 11b1 comprises fibers constituting the skin-side core pack 11b1 and a composition containing a hydrophilic solvent supported on the fibers. In other words, the skin-side core pack 11b1 comprises (is coated with) a composition containing a hydrophilic solvent.

[0098] Here, as mentioned above, examples of fibers constituting the skin-side core patch 11b1 include synthetic resin fibers, pulp fibers, and mixtures thereof. The composition is a composition containing a functional agent having a predetermined function in a hydrophilic solvent. Examples of functional agents having a predetermined function include antibacterial agents, deodorants, thermosensitive agents, traditional Chinese medicines, fragrances, and mixtures of at least two of these. The hydrophilic solvent refers to a solvent that is mixed with water in any ratio; examples include water, solvents of hydrophilic organic substances, and mixtures thereof.

[0099] In the disposable diaper 1 described above, the fibers constituting the skin-side core 11b1 carry a composition containing a hydrophilic solvent, thus utilizing the effect of the hydrophilic solvent to facilitate the fibers' affinity for bodily fluids. Therefore, during use, bodily fluids released into the disposable diaper 1 and transferred from the surface sheet 12 to the skin-side core 11b1 can further diffuse along the planar direction of the skin-side core 11b1. That is, the planar fluid diffusivity of the skin-side core 11b1 can be further improved. Consequently, rewetting of the disposable diaper 1 can be further suppressed.

[0100] Alternatively, the fibers constituting the surface sheet 12 may carry a composition containing a hydrophilic solvent. In other words, the surface sheet 12 may also contain (or be coated with) a composition containing a hydrophilic solvent. In this case, the composition of the surface sheet 12 transfers to the skin-side core pack 11b1 over time, achieving the same effect as when the composition is disposed on the skin-side core pack 11b1. Furthermore, in such a case, the amount of composition contained in the surface sheet 12 is less than the amount of composition contained in the skin-side core pack 11b1.

[0101] In a preferred embodiment of this invention, the composition further comprises a hydrophilic antibacterial agent. In other words, the functional agent contained in the composition comprises a hydrophilic antibacterial agent.

[0102] Here, a hydrophilic antibacterial agent is defined as one that dissolves in 40g or more of 100g of water at 25°C within 5 hours. There are no particular limitations on the type of antibacterial agent, as long as it is hydrophilic and possesses antibacterial function (i.e., the ability to inhibit bacterial proliferation). Examples of types of antibacterial agents include cationic antibacterial agents. Examples of cationic antibacterial agents include guanidine antibacterial agents, biguanide antibacterial agents, and quaternary ammonium salts. Examples of guanidine antibacterial agents include polyhexamethylene guanidine (PHMG), and examples of biguanide antibacterial agents include polyhexamethylene biguanide (PHMB), also known as polyaminopropyl biguanide. Examples of quaternary ammonium salts include benzalkonium chloride and benzyl chloride. The above-mentioned antibacterial agents can be used alone or in combination.

[0103] In the disposable diaper 1 described above, the fibers constituting the skin-side core 11b1 carry a composition containing a hydrophilic antibacterial agent. Through the effect of the hydrophilic antibacterial agent, the fibers become more readily compatible with bodily fluids. Therefore, during use, bodily fluids released into the disposable diaper 1 and transferred from the surface sheet 12 to the skin-side core 11b1 can further diffuse along the planar direction within the skin-side core 11b1. That is, the planar fluid diffusion within the skin-side core 11b1 can be further improved. This further suppresses rewetting of the disposable diaper 1. Furthermore, the antibacterial agent can impart antibacterial properties to bodily fluids transferred from the surface sheet 12 to the absorbent body 11.

[0104] In a preferred embodiment of this invention, the solvent comprises a non-volatile organic compound. In other words, the solvent contained in the composition comprises a hydrophilic and non-volatile organic compound.

[0105] Here, non-volatile organic compounds (solvents) refer to organic solvents with a vapor pressure of 50 Pa or less at 25°C. There are no particular limitations on the type of solvent, as long as it is a hydrophilic, non-volatile organic compound capable of dissolving antibacterial agents. Examples of solvent types include glycols and alcohols. Examples of glycols include propylene glycol (PG), dipropylene glycol (DPG), 1,3-butanediol (BG), and polyethylene glycol 400 (PEG400). Examples of alcohols include 3-methoxy-3-methyl-1-butanol. The solvents for the aforementioned organic compounds can be used individually or in combination.

[0106] In the disposable diaper 1 described above, the fibers constituting the skin-side core 11b1 carry a solvent containing a hydrophilic and non-volatile organic compound. Through the effect of the hydrophilic and non-volatile organic compound, the affinity between body fluids and fibers can be stably and continuously maintained. Therefore, during use, body fluids released into the disposable diaper 1 and transferred from the surface sheet 12 to the skin-side core 11b1 can further diffuse along the planar direction within the skin-side core 11b1. That is, the planar liquid diffusivity within the skin-side core 11b1 can be further improved. This further suppresses backflow of the disposable diaper 1. Furthermore, because the hydrophilic and non-volatile organic compound is not easily volatilized, it can suppress skin irritation.

[0107] As a preferred embodiment, the lower limit of viscosity at 25°C in the composition (containing an antibacterial agent and a solvent of hydrophilic and non-volatile organic compounds) is, for example, 5 mPa·s, and preferably 50 mPa·s. By setting the lower limit of viscosity within this range, the composition can be easily and stably held on the surface of the fiber without moving vertically downwards (or falling), thus enabling more stable and sustained application of the affinity between bodily fluids and fibers. The upper limit, from the viewpoint of ease of coating, is, for example, 12000 mPa·s. Furthermore, as a method for measuring viscosity, it is measured using a Thermo Fisher Scientific Co., Ltd. HAAKE RheoStress 1 (sensor: Cone φ60mm, 1°angle C60 / 1) under the conditions of 38 ml of composition, temperature 25°C, humidity 50%, and shear rate of 10.0 (l / s).

[0108] From the viewpoint of ensuring antibacterial effect, the lower limit of the total proportion of antibacterial agent and solvent relative to the composition can be, for example, 90% by mass, preferably 95% by mass or more. Alternatively, the composition may contain, in addition to the antibacterial agent and the solvent containing the organic matter, other solvents, exemplified by water. In the solvent, from the viewpoint of suppressing the volatility of the composition and suppressing rusting of the manufacturing apparatus, it is preferable that the amount of water is less than the amount of the solvent containing the organic matter. Furthermore, from the viewpoint of ensuring antibacterial effect, the lower limit of the proportion of antibacterial agent relative to the total proportion of antibacterial agent and solvent can be, for example, 1% by mass, preferably 2% by mass. From the viewpoint of dissolution in the solvent, the upper limit of the proportion of antibacterial agent relative to the total proportion of antibacterial agent and solvent can be, for example, 60% by mass, preferably 50% by mass. Moreover, the solvent of the composition can be identified and quantified using GC / MS (gas chromatography-mass spectrometry), and the antibacterial agent of the composition can be identified and quantified using LC / MS (high performance liquid chromatography-mass spectrometry).

[0109] As a preferred embodiment, in the skin-side core pack 11b1, the unevenness at the central portion in the length direction L and the central portion in the width direction W is less than the unevenness at the two ends in the length direction L and the two ends in the width direction W.

[0110] Here, the central portion of the skin-side core piece 11b1 along the length L can be exemplified by, for example, the central portion (1) excluding the two ends (1) when the skin-side core piece 11b1 is divided into 3 parts along the length L, preferably 3 equal parts, when viewed from above; the central portions (2) excluding the two ends (1) when the skin-side core piece 11b1 is divided into 4 parts along the length L, preferably 4 equal parts; and the central portions (3 or 1) excluding the two ends (1 or 2) when the skin-side core piece 11b1 is divided into 5 parts along the length L, preferably 5 equal parts. The central portion along the length L is appropriately set according to the performance required by the disposable diaper 1.

[0111] On the other hand, the central portion in the width direction W of the skin-side core pack 11b1 can be, for example, the central portion (1) excluding the two ends (1 each) when the skin-side core pack 11b1 is divided into 3 parts in the width direction W, preferably 3 equal parts, when viewed from above; the central portion (2) excluding the two ends (1 each) when the skin-side core pack 11b1 is divided into 4 parts in the width direction W, preferably 4 equal parts; and the central portion (3 or 1) excluding the two ends (1 or 2 each) when the skin-side core pack 11b1 is divided into 5 parts in the width direction W, preferably 5 equal parts. The central portion in the width direction W described above is appropriately set according to the performance required by the disposable diaper 1.

[0112] like Figure 4 As shown, in this embodiment, in the skin-side core sheet 11b1, when viewed from above, the central portion in the length direction L and the central portion in the width direction W are referred to as the central region TA, the portion outside of it is referred to as the outer region MTA, and the portion of the outer region MTA that overlaps with the absorbent core 11a is referred to as the outer central region NTA (these definitions also apply to the surface sheet 12 and the back sheet 13 that overlap in the thickness direction T). The central region TA in the skin-side core sheet 11b1 is a portion with less unevenness, and when viewed from above, it includes the area where the discharge port abuts, and is the area that overlaps with the absorbent core 11a. In this embodiment, the central region TA is the central portion (two) when the skin-side core sheet 11b1 is divided into four equal parts in the length direction L and the central portion (one) when the skin-side core sheet 11b1 is divided into three equal parts in the width direction W. To make the central region TA of the skin-side core sheet 11b1 less uneven, for example, it can be achieved by coating the central region TA with a composition.

[0113] As described above, in the disposable diaper 1, the unevenness in the central portion of the skin-side core 11b1, which is both the central portion in the length direction L and the central portion in the width direction W, i.e., the discharge port contact area (central region TA), is relatively small. Therefore, the planar fluid diffusion in the discharge port contact area of ​​the skin-side core 11b1 is relatively large. Consequently, during use, the body fluid released into the discharge port contact area in the skin-side core 11b1 can diffuse more rapidly along the planar direction and then transfer to the absorbent core 11a. Therefore, a very large area of ​​body fluid within the absorbent body 11 (including the outer central region NTA) can be absorbed, thereby preventing backflow in the disposable diaper 1.

[0114] Furthermore, in the disposable diaper 1, the unevenness in the region of the skin-side core cover 11b1, specifically the regions at both ends in the length direction L and the width direction W—that is, the regions at the ends of the absorbent body 11 (hereinafter also referred to as "end regions")—is relatively large. Therefore, the planar fluid diffusion in the end regions of the skin-side core cover 11b1 is relatively small. Consequently, during use, the diffusion of bodily fluids from the discharge port contact area (central region TA) outwards can be suppressed in the end regions. Thus, during use, leakage of bodily fluids to the outside of the disposable diaper 1 can be suppressed in the end regions. In this embodiment, the end region is the region further outward than the central region TA, specifically the outer central region NTA or its periphery.

[0115] As a preferred embodiment, the unevenness of the skin-side core packing 11b1 is less than that of the skin-side surface packing 12.

[0116] Here, as the surface sheet 12, examples include sheets with irregularities, such as sheets having a plurality of protrusions extending along the length direction L and arranged at intervals in the width direction W, and a plurality of recesses provided between the protrusions, and sheets in which the plurality of protrusions are generally circular when viewed from above and arranged in a checkered pattern when viewed from above. Furthermore, in this embodiment, the height (average) of the irregularities in the surface sheet 12 can be, for example, 0.2 mm to 3 mm. The width D (average) of the irregularities can be, for example, 0.1 mm to 3 mm.

[0117] As described above, in the disposable diaper 1, by making the unevenness of the skin-side core piece 11b1 relatively smaller than that of the skin-side surface piece 12, it is easier for the skin-side core piece 11b1 to come into contact with the surface piece 12. Therefore, during use, bodily fluids released onto the surface piece 12 can quickly transfer from the surface piece 12 to the skin-side core piece 11b1, and can then diffuse along the planar direction within the skin-side core piece 11b1 before transferring to the absorbent core 11a. Furthermore, by making the unevenness of the skin-side surface piece 12 relatively larger, bodily fluids absorbed by the absorbent core 11a are less likely to come into contact with the wearer's skin via the surface piece 12, thus reducing the likelihood of backflow.

[0118] In a preferred embodiment, the surface opposite to the convex portion of the wrinkled paper in the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 is formed as a concave shape. In other words, as... Figure 3 As shown in (b), in the crepe paper, the protrusion 51 is not solid, and its opposite side forms a recessed portion 52. Furthermore, the recessed portion 52 on the opposite side of the protrusion 51 contains a portion of the pulp fibers of the absorbent core 11a. That is, the recessed portion 52 is filled with pulp fibers.

[0119] As described above, in the disposable diaper 1, a portion of the pulp fibers of the absorbent core 11a are contained in the crease of the skin-side core 11b1 within the crease of the diaper 1, in the recess 52 on the side opposite to the protrusion 51. This allows for a larger contact area between the skin-side core 11b1 and the absorbent core 11a. Consequently, during use, bodily fluids excreted into the disposable diaper 1 can be rapidly transferred from the skin-side core 11b1 to the absorbent core 11a.

[0120] Furthermore, in the crepe paper within the non-skin-side core sheet 11b2, a portion of the pulp fibers of the absorbent core 11a is included in the recess 52 on the side opposite to the protrusion 51. This allows bodily fluids that have not been completely absorbed by the absorbent core 11a to easily diffuse along the planar direction, and enables the absorbent core 11a at its end along the length direction L and / or width direction W to absorb the fluid.

[0121] Furthermore, by including pulp fibers in the portion of the recessed portion 52 of the skin-side core pack 11b1 and the portion of the recessed portion 52 of the non-skin-side core pack 11b2, it is possible to prevent the skin-side core pack 11b1 and the non-skin-side core pack 11b2 from becoming excessively deformed, which would lead to a decrease in absorption performance (e.g., absorption rate, absorption amount).

[0122] As a preferred embodiment of this invention, the disposable diaper 1 is provided with a plurality of non-skin side elastic members 17 (and / or non-skin side elastic members 18) extending along the length direction L at a position that overlaps with the absorbent body 11 in the thickness direction T and is located on the non-skin side of the absorbent body 11 in the thickness direction T.

[0123] As described above, the disposable diaper 1 has a non-skin-side elastic member 17 (and / or a non-skin-side elastic member 18), thus allowing the skin-side portion of the absorbent body 11 to be easily pressed against the body. Therefore, during use, bodily fluids released into the disposable diaper 1 can be transferred more rapidly from the surface sheet 12 to the absorbent body. Furthermore, the non-skin-side core sheet 11b2 can be reinforced using the non-skin-side elastic member 17 (and / or the non-skin-side elastic member 18), thereby further suppressing breakage of the non-skin-side core sheet 11b2.

[0124] As a preferred embodiment, the disposable diaper 1 further comprises a pair of leak-proof walls 15 located on both sides of the surface sheet 12 in the width direction W and extending along the length direction L. Each pair of leak-proof walls 15 includes a leak-proof elastic member 16 extending along the length direction L. The contractile force per unit length of the leak-proof elastic member 16 is smaller than the contractile force per unit length of the non-skin-side elastic member 17 (and / or non-skin-side elastic member 18).

[0125] As described above, in the disposable diaper 1, due to the presence of a pair of leak-proof walls 15 with leak-proof elastic members 16, side leakage of bodily fluids along the width direction W can be suppressed. Furthermore, since the non-skin side elastic member 17 (and / or non-skin side elastic member 18) has a greater contractile force per unit length than the leak-proof elastic member 16 on the non-skin side, it is easier to press the skin side portion of the absorbent body 11 against the body. Therefore, during use, side leakage of bodily fluids released into the disposable diaper 1 can be suppressed, and the bodily fluids can be transferred more rapidly from the surface sheet 12 to the absorbent body 11.

[0126] As another implementation method, it can also be, as in Figure 1 As hypothetically represented, the disposable diaper 1 has a pair of embossed portions E, which are formed into grooves along the thickness direction T from the surface of the surface sheet 12 toward the absorbent body 11 and extend along the length direction L. The degree of unevenness in the region between the pair of embossed portions E of the skin-side core sheet 11b1 is less than the degree of unevenness in the region of the skin-side core sheet 11b1 located outside the width direction W of each of the pair of embossed portions E.

[0127] As described above, in the disposable diaper 1, the unevenness in the area (inner region) between the pair of embossed portions E of the skin-side core 11b1 is relatively small. Therefore, the planar fluid diffusion in the inner region of the skin-side core 11b1 is relatively large. Consequently, during use, bodily fluid released into the inner region can diffuse more rapidly along the planar direction (outer side of the inner region) and then transfer to the absorbent core 11a. Therefore, a very large area of ​​bodily fluid within the absorbent core 11 can be absorbed, thereby reducing the likelihood of backflow in the disposable diaper 1. The inner region can be defined as the region having the width between the pair of embossed portions E in the width direction W and extending along the length direction L within the absorbent core 11a, including the central region TA.

[0128] Furthermore, the unevenness in the region (outer region) of the skin-side core piece 11b1 located on the outer side of each pair of embossed portions E in the width direction is relatively large. Therefore, the planar fluid diffusion in the outer region of the skin-side core piece 11b1 is relatively small. Thus, during use, the diffusion of bodily fluids from the inner region outwards (across the embossed portions) can be suppressed in the outer region, and the bodily fluids can be transferred towards the absorbent core 11a. Therefore, during use, leakage of bodily fluids to the outside of the disposable diaper 1 can be suppressed in the outer region. The outer region can be considered as the area within the absorbent core 11a that is substantially excluding the central region TA.

[0129] Next, the method for manufacturing the absorbent article according to the embodiment will be described. Figure 5 This is a schematic diagram illustrating an example of a method for manufacturing an absorbent article according to an embodiment.

[0130] The absorbent article, namely the disposable diaper 1, manufactured using this manufacturing method has the structure described above. Specifically, the disposable diaper 1 includes a surface sheet 12, a back sheet 13, and an absorbent body 11 located between the surface sheet 12 and the back sheet 13. The absorbent body 11 includes: an absorbent core 11a comprising pulp fibers; a skin-side core sheet 11b1 located on the skin side of the absorbent core 11a in the thickness direction T; and a non-skin-side core sheet 11b2 located on the non-skin side of the absorbent core 11a in the thickness direction T.

[0131] This manufacturing method includes a preparation step S1 and a forming step S2, wherein the forming step S2 includes a coating step S21.

[0132] In the preparation step S1, a continuous surface sheet 112 formed by continuous surface sheet 12, a continuous skin-side core sheet 111b1 formed by continuous skin-side core sheet 11b1 formed by continuous skin-side core sheet 11b1 formed by continuous skin-side core sheet 11b1 formed by continuous skin-side core sheet 11b1 formed by continuous skin-side core sheet 11b2 formed by continuous non-skin-side core sheet 11b2 formed by continuous non-skin-side core sheet 11b2 formed by continuous non-skin-side core sheet 11b2 formed by continuous skin-side core sheet 11a, a plurality of absorbent cores 11a, and a continuous back sheet 113 formed by continuous back sheet 13 are prepared.

[0133] In this embodiment, a continuous outer cover sheet 114 with a continuous leak-proof wall 15 is also prepared, which is formed by continuously forming an outer cover sheet 14 (including a leak-proof elastic member 16 and non-skin-side elastic members 17, 18). Then, a continuous back cover sheet 113 is stacked at the center of the width direction W on the skin side of the continuous outer cover sheet 114 with the continuous leak-proof wall 115, thereby preparing a continuous laminate 120 composed of the continuous back cover sheet 113, the continuous outer cover sheet 114, and the continuous leak-proof wall 115.

[0134] In this embodiment, the skin-side core pack 11b1 (divided into two parts in the width direction W) and the non-skin-side core pack 11b2 are integrally formed, so the continuous skin-side core pack 111b1 (divided into two parts in the CD direction) and the continuous non-skin-side core pack 111b2 are an integral continuous core pack 111b.

[0135] In the forming process S2, a laminate is formed by stacking a portion of the surface sheet 12 of the continuous surface sheet 112, a portion of the skin-side core packing 11b1 of the continuous skin-side core packing 111b1, an absorbent core 11a, a portion of the non-skin-side core packing 11b2 of the continuous non-skin-side core packing 111b2, and a portion of the back sheet 13 of the continuous back sheet 113 in the above order.

[0136] First, such as Figure 5 As shown in (a), an absorbent core 11a is placed in a portion (center in the CD direction) of the continuous non-skin side core packing 111b2 in the continuous core packing 111b.

[0137] Next, as Figure 5 As shown in (b), the continuous skin-side core-packing sheets 111b1 located on both sides of the absorbent core 11a in the CD direction of the continuous core-packing sheets 111b are folded and joined to the absorbent core 11a. Then, the front and rear sides of the absorbent core 11a in the MD direction of the continuous core-packing sheets 111b are cut to the size of an absorbent body 11. Thus, an absorbent body 11 is formed by stacking the skin-side core-packing sheets 11b1, the absorbent core 11a, and the non-skin-side core-packing sheets 11b2 in the above order.

[0138] Next, as Figure 5As shown in (c), a portion of the surface sheet 12 of the continuous surface sheet 112 and the absorber 11 are arranged opposite to each other.

[0139] Next, as Figure 5 As shown in (d), a portion of the surface sheet 12 of the continuous surface sheet 112 is joined to the absorber 11. Simultaneously, a portion of the back sheet 13 of the continuous back sheet 113 is arranged opposite to the absorber 11. In this embodiment, the portion of the back sheet 13 and the absorber 11 are arranged opposite to each other in the continuous laminate 120 composed of the continuous back sheet 113, the continuous outer sheet 114, and the continuous leak-proof wall 115.

[0140] Next, as Figure 5 As shown in (e), a portion of the surface sheet 12 of the continuous surface sheet 112 is joined to a portion of the back sheet 13 in the continuous laminate 120, and a portion of the absorbent body 11 is joined to a portion of the back sheet 13 in the continuous laminate 120. Then, the front and rear sides of the continuous surface sheet 112 and the absorbent core 11a in the MD direction of the continuous laminate 120 are cut to the size of one surface sheet 12 and one back sheet 13 (and one outer sheet 14 and one leak-proof wall 15). Thus, an absorbent body 10 is formed by stacking the surface sheet 12, the absorbent body 11, and the back sheet 13 (and the outer sheet 14 and leak-proof wall 15) in the above order.

[0141] Here, it is also possible that a portion of the surface sheet 12 of the continuous surface sheet 112 is joined to the absorber 11. Figure 5 (c) process), and the joining of the absorber 11 and the back sheet 13 portion of the continuous laminate 120 ( Figure 5 The (d) process is carried out simultaneously.

[0142] Among them, forming process S2 includes coating process S21. Coating process S21 is a process (schematically represented by P1): in Figure 5 In (b), after folding the continuous skin-side core piece 111b1, a composition containing a hydrophilic solvent is applied to a portion of the continuous skin-side core piece 111b1 or the skin-side core piece 11b1 of the absorbent 11. In this case, the composition is applied to the skin-side surface of the skin-side core piece 11b1. Examples of application methods include non-contact application (e.g., spraying the composition onto the skin-side core piece 11b1 using a spray device) or contact application (e.g., spraying the composition onto the skin-side core piece 11b1 from a nozzle). The application location is a relatively flat area, as described in the embodiment of disposable diaper 1.

[0143] Alternatively, coating process S21 can be a process like this (indicated schematically by P2): in Figure 5In (c), a composition containing a hydrophilic solvent is applied to a portion of the surface sheet 12 in the continuous surface sheet 112. In this case, the composition is applied to the skin-side or non-skin-side surface of the portion of the surface sheet 12. The application method is as described above. Furthermore, after application, when the continuous surface sheet 112 and the absorbent 11 are joined, the composition is transferred from the portion of the surface sheet 12 to the skin-side core pack 11b1. The transfer can be substantially controlled by adjusting the viscosity of the composition. The application location is a portion of the skin-side core pack 11b1 with relatively less unevenness, as described in the embodiment of disposable diaper 1.

[0144] Alternatively, coating process S21 can be a process like this (illustrated by P3): in Figure 5 In (d), a composition containing a hydrophilic solvent is applied to a portion of the surface sheet 12 in the continuous surface sheet 112. In this case, the composition is applied to the skin-side surface of the portion of the surface sheet 12. The application method is as described above. Furthermore, after application, the composition is transferred from the portion of the surface sheet 12 to the skin-side core sheet 11b1. The transfer can be roughly controlled by adjusting the viscosity of the composition. The application location is a portion of the skin-side core sheet 11b1 with relatively less unevenness, as described in the embodiment of disposable diaper 1.

[0145] The coating process S21 can be carried out by implementing any one of the three methods mentioned above, but it can also be carried out by combining two or more methods.

[0146] Here, the unevenness of the skin-side core sheet 11b1 portion in the continuous skin-side core sheet 111b1 after forming step S2 is less than the unevenness of the non-skin-side core sheet 11b2 portion in the continuous non-skin-side core sheet 111b2. This is because, in the coating step S21, by coating or transferring a solvent-containing composition to the skin-side core sheet 11b1 portion of the continuous skin-side core sheet 111b1, the coated portion becomes soft and smoothed by liquid immersion, thus reducing the unevenness.

[0147] Then, the ventral portion 2 is joined at one end of the absorbent body 10 along the length L, and the dorsal portion 3 is joined at the other end of the absorbent body 10 along the length L, to manufacture a disposable diaper 1.

[0148] In this manufacturing method, the composition coated on the surface sheet 12 and transferred to the skin-side core pack 11b1 in contact with the surface sheet 12, or the composition coated on the skin-side core pack 11b1, can be used to make the unevenness of the skin-side core pack 11b1 relatively small. Therefore, the contact area between the surface sheet 12 and the skin-side core pack 11b1 can be large. As a result, the stability of the bonding between the surface sheet 12 and the skin-side core pack 11b1 can be improved. At the same time, since the unevenness of the skin-side core pack 11b1 of the manufactured disposable diaper 1 is relatively small, during use, bodily fluids (including sweat) released into the disposable diaper 1 and transferred from the surface sheet 12 to the skin-side core pack 11b1 can diffuse along the planar direction in the skin-side core pack 11b1 and then transfer to the absorbent core 11a. Therefore, since it can absorb bodily fluids over a very large area within the absorbent body 11, the amount of bodily fluid absorbed per unit area when viewed from above is reduced. This makes it less likely for the disposable diaper 1 to re-leak after absorbing bodily fluids. Furthermore, by making the non-skin side core 11b2 of the crepe paper relatively more textured, it is easier to deform the non-skin side core 11b2, thereby preventing breakage of the non-skin side core 11b2 and the skin side core 11b1 during use.

[0149] Furthermore, the method for making the unevenness of the skin-side core piece 11b1 less than that of the non-skin-side core piece 11b2 is not limited to the method described above. For example, in the preparation step S1, crepe paper with a smaller unevenness may be used for the skin-side core piece 11b1 (continuous skin-side core pieces 111b1), while crepe paper with a larger unevenness may be used for the non-skin-side core piece 11b2 (continuous non-skin-side core pieces 111b2).

[0150] In this embodiment, as a preferred method, in the coating step S21, the composition is coated on at least one of the central portions of the length direction L and the width direction W of the portion of the surface sheet 12 in the continuous surface sheet 112, and the central portions of the length direction L and the width direction W of the portion of the skin side core pack 11b1 in the continuous skin side core pack 111b1.

[0151] In the manufacturing method, the composition is applied to the central portion of the surface sheet 12 or the skin-side core packing 11b1 in the length direction L and the width direction W, that is, the approximate discharge port contact area. As a result, the unevenness of the skin-side core packing 11b1 in the discharge port contact area can be relatively small. Therefore, the contact area in the discharge port contact area of ​​the surface sheet 12 and the skin-side core packing 11b1 can be further increased. This further improves the stability of the bonding between the surface sheet 12 and the skin-side core packing 11b1.

[0152] Furthermore, the composition is applied to the ends other than the central portion in the length direction L and the central portion in the width direction W of the surface sheet 12 or the skin-side core sheet 11b1. In this way, by not applying the composition to the ends in the length direction L and the width direction W, where the adhesive is primarily applied when the sheets are joined together, the adhesive can function properly at the ends. This prevents obstacles such as sheet roll-up at the ends of the disposable diaper from occurring during transport in the manufacturing process due to the adhesive failing to function properly.

[0153] In this embodiment, as a preferred method, in the coating step S21, the composition is coated, when viewed from above, in at least one of the areas in the continuous surface sheet 112 where the absorbent core 11a is disposed, and in the areas in the continuous skin-side core sheet 111b1 where the absorbent core 11a is disposed.

[0154] In this manufacturing method, when viewed from above, the composition is applied only to the area where the absorbent core 11a is disposed within the surface sheet 12 or the skin-side core sheet 11b1. By limiting the area where the composition is applied, even when the skin-side core sheet 11b1 and the non-skin-side core sheet 11b2 are joined outside the area where the absorbent core 11a is disposed, diffusion of the composition from the skin-side core sheet 11b1 to the non-skin-side core sheet 11b2 can be suppressed. This prevents the non-skin-side core sheet 11b2 from becoming less smooth and the adhesive from failing to function properly when the sheets are joined together.

[0155] In this embodiment, as a preferred embodiment, the composition further comprises a hydrophilic antibacterial agent, and the solvent comprises water and an organic solvent, wherein the amount of water in the solvent is less than the amount of the organic solvent.

[0156] In this manufacturing method, the composition further includes a hydrophilic antibacterial agent, and the solvent includes water and an organic solvent, with the amount of water being less than the amount of organic solvent. Thus, by reducing the water ratio in the composition, rust formation in the manufacturing apparatus can be suppressed. On the other hand, by increasing the organic solvent ratio in the composition, the possibility of the antibacterial agent itself being exposed on the surface of the surface sheet and irritating the wearer's skin can be suppressed.

[0157] <Methods for measuring the unevenness of the core package>

[0158] The unevenness of the core cladding is measured as follows.

[0159] (1) Divide the absorbent material into three equal parts in the width and length directions to prepare nine samples.

[0160] (2) After freezing each sample with liquid nitrogen, cut it along the thickness direction with a sharp cutter in a manner that does not deform the unevenness, so that the part of each sample whose unevenness is to be measured can be observed in cross-section (e.g., the central part in the length direction and the central part in the width direction, and the part in the front and back directions in the length direction). Alternatively, the size of the cut can be set to 1cm × 1cm.

[0161] (3) Prepare a microscope or optical microscope (e.g., KEYENCE VHX-7000) and take images of the cross-section of each sample at a magnification of 10x to 100x.

[0162] (4) In the images of each sample, for each concave and convex part, measure the number of concave and convex parts (wrinkles) per unit length and / or the height H of the concave and convex parts, and / or the width D of the concave and convex parts.

[0163] (5) Calculate the average of the measurements of nine (however, in cases where the difference is large due to different locations (±30% or more) the three nearest) specimens as the final number of bumps (wrinkles) per unit length and / or the height H of the bumps, and / or the width D of the bumps.

[0164] <Method for measuring the coating area of ​​antibacterial solution (containing antibacterial agent)>

[0165] The method for measuring the amount of antibacterial solution (containing antibacterial agent) in the area coated is as follows.

[0166] (1) Cut out a portion of the absorbent article that you want to confirm whether it has been coated with antibacterial liquid at a predetermined size (e.g., 1cm × 1cm) as a sample.

[0167] (2) For the sample, the antibacterial agent was identified and quantified by LC / MS (high performance liquid chromatography-mass spectrometry).

[0168] (3) Perform the above (1) to (2) on the three samples, calculate their average value and determine the presence and amount of antibacterial liquid in that part.

[0169] (4) Perform (1) to (3) above on multiple parts of the absorbent article to determine the area coated with antibacterial liquid and the amount of antibacterial liquid in that area.

[0170] Example

[0171] The present invention will now be described based on embodiments, but the present invention is not limited to the embodiments.

[0172] (1) Sample

[0173] (a) Example 1

[0174] Produced with a unit area weight of 30g / m² 2 Surface sheet (hot air nonwoven fabric), unit area weight 15g / m 2 Skin-side core wrap (thin crepe paper), unit area weight 60g / m 2 Absorbent core (pulp fiber), unit area weight 15g / m 2 Non-skin-friendly side core wrap (thin crepe paper), unit area weight 35g / m 2 The back sheet (breathable film) simulates the absorbent body. A simulated composition (1,3-butanediol (BG)) was applied to approximately the entire surface of the skin-side core sheet using a spray device. It was confirmed that in this sample, before adhesion, the unevenness of the wrinkles was almost invisible to the naked eye due to the hydrophilic solvent. Furthermore, the unevenness height measured under a microscope was 0.015 mm.

[0175] (b) Comparative Example 1

[0176] A simulated absorbent substrate with the same structure as in Example 1 was fabricated. However, the simulated composition (1,3-butanediol (BG)) was not applied to the skin-side core patch. It was confirmed that, in this sample, due to the absence of a hydrophilic solvent before adhesion, the presence of wrinkles and unevenness was visually apparent. Furthermore, the height of the unevenness, measured under a microscope, was 0.025 mm.

[0177] (2) Evaluation methods

[0178] In the samples of Example 1 and Comparative Example 1, 0.5 ml of artificial blood was dropped from a height of 5 mm above the surface sheet, and the degree of diffusion of the artificial blood in the surface sheet and the skin-side core pack was measured after 3 minutes. As a measure of the degree of diffusion, the spread width of the artificial blood was measured in the MD and CD directions during the manufacturing of each sheet. The artificial blood was prepared as follows: 80 g of glycerol, 8 g of sodium carboxymethyl cellulose (CMC), 10 g of NaCl, 4 g of NaHCO3, 8 g of red pigment No. 102, 2 g of red pigment No. 2, and 2 g of yellow pigment No. 5 were mixed with 1000 cc of water, and the viscosity was approximately in the range of about 22 mPa·s to about 26 mPa·s.

[0179] (3) Evaluation results

[0180] (a) Example 1

[0181] Within the surface patch, the artificial blood diffused 17 mm in the MD direction and 18 mm in the CD direction. On the other hand, within the skin-side core patch, the artificial blood diffused 31 mm in the MD direction and 35 mm in the CD direction.

[0182] (b) Comparative Example 1

[0183] Within the surface patch, the artificial blood diffused 23 mm in the MD direction and 20 mm in the CD direction. On the other hand, within the skin-side core patch, the artificial blood diffused 28 mm in the MD direction and 23 mm in the CD direction.

[0184] (c) Summary

[0185] When comparing Example 1 and Comparative Example 1, it was determined that, for the one in which the composition was applied to the skin-side core pack to reduce the unevenness (Example 1), compared to the other (Comparative Example 1), the artificial blood rapidly moved from the surface pack to the skin-side core pack and rapidly diffused in the planar direction within the skin-side core pack.

[0186] The disposable diaper and its manufacturing method of the present invention are not limited to the above-described embodiments. Within the scope of the purpose and spirit of the present invention, the embodiments can be combined with each other and known technologies can be applied.

[0187] Explanation of reference numerals in the attached figures

[0188] 1. Absorbent material; 11. Absorbent body; 11a. Absorbent core; 11b1. Skin-side core pack; 11b2. Non-skin-side core pack.

Claims

1. An absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet, wherein, The absorber includes: Absorbent core, which contains pulp fibers; A skin-side core packing located on the skin side of the absorbent core in the thickness direction; and The non-skin-side core packing is located on the non-skin-side of the absorbent core in the thickness direction. The skin-side core pack and the non-skin-side core pack are made of textured paper with raised and recessed surfaces. The skin-side core pack has a less uneven surface than the non-skin-side core pack.

2. The absorbent article according to claim 1, wherein, The skin-side core packing includes: Fibers, which constitute the skin-side core packing; and The composition, which is supported on the fiber, contains a hydrophilic solvent.

3. The absorbent article according to claim 2, wherein, The composition also contains a hydrophilic antibacterial agent.

4. The absorbent article according to claim 3, wherein, The solvent contains non-volatile organic compounds.

5. The absorbent article according to any one of claims 1 to 4, wherein, In the skin-side core pack, the degree of unevenness at the central portion in the length direction and the central portion in the width direction is less than the degree of unevenness at the two ends in the length direction and the two ends in the width direction.

6. The absorbent article according to any one of claims 1 to 5, wherein, The skin-side core packing has a less uneven surface than the skin-side surface packing.

7. The absorbent article according to any one of claims 1 to 6, wherein, For the wrinkled paper in the skin-side core pack and the wrinkled paper in the non-skin-side core pack, the surface opposite to the convex portion of the concave-convex structure is formed as concave. The concave portion contains a portion of the pulp fibers of the absorbent core.

8. The absorbent article according to any one of claims 1 to 7, wherein, The absorbent article further comprises a non-skin elastic member extending along the length direction at a position where it overlaps with the absorbent in the thickness direction and is located on the non-skin side of the absorbent in the thickness direction.

9. The absorbent article according to claim 8, wherein, The absorbent article also includes a pair of leak-proof walls located on both sides of the surface sheet in the width direction and extending along the length direction. The pair of leak-proof walls each include a leak-proof elastic member extending along the length direction. The contractile force per unit length of the leak-proof elastic member is smaller than the contractile force per unit length of the non-skin-side elastic member.

10. The absorbent article according to any one of claims 1 to 9, wherein, The absorbent article has a pair of embossed portions formed as grooves extending along the length direction from the surface of the surface sheet toward the absorbent body. The unevenness in the region between the pair of embossed portions of the skin-side core pack is less than the unevenness in the region of the skin-side core pack located on the outer side of each of the pair of embossed portions in the width direction.

11. A method for manufacturing an absorbent article, the absorbent article having mutually orthogonal length, width, and thickness directions, and comprising a surface sheet, a back sheet, and an absorbent body located between the surface sheet and the back sheet, the absorbent body comprising: An absorbent core comprising pulp fibers; a skin-side core sheet located on the skin side in the thickness direction of the absorbent core; And a non-skin side core packing, which is located on the non-skin side of the absorbent core in the thickness direction, wherein, The method for manufacturing this absorbent material includes: The preparation process includes preparing a continuous surface sheet formed from the surface sheet, a continuous skin-side core sheet formed from the skin-side core sheet formed from textured crepe paper, a continuous non-skin-side core sheet formed from the non-skin-side core sheet formed from textured crepe paper, a plurality of absorbent cores, and a continuous back sheet formed from the back sheet; and The forming process involves forming a laminate by stacking portions of the continuous surface sheet, portions of the continuous skin-side core sheet, the absorbent core, portions of the continuous non-skin-side core sheet, and portions of the continuous back sheet in the above-described order. The forming process includes a coating process in which a composition comprising a hydrophilic solvent is coated onto at least one of a portion of the continuous surface sheet and a portion of the continuous skin-side core sheet. The unevenness of the skin-side core portion of the continuous skin-side core package after the forming process is less than the unevenness of the non-skin-side core package portion of the continuous non-skin-side core package.

12. The method according to claim 11, wherein, In the coating process, the composition is coated on at least one of the central portions of the length direction and the central portions of the width direction of the portion of the surface sheet in the continuous surface sheet, and the central portions of the length direction and the central portions of the width direction of the portion of the skin-side core pack in the continuous skin-side core pack.

13. The method according to claim 11 or 12, wherein, In the coating process, the composition, when viewed from above, is coated on at least one of the regions in the continuous surface sheet where the absorbent core is disposed, and the regions in the continuous skin-side core sheet where the absorbent core is disposed.

14. The method according to any one of claims 11 to 13, wherein, The composition also contains a hydrophilic antibacterial agent. The solvent includes water and organic solvents. In the solvent, the amount of water is less than the amount of the organic solvent.

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