TWI584791B - Absorbent items - Google Patents

Description

Absorbent article

The present invention relates to an absorbent article such as a menstrual napkin or a disposable diaper, an incontinence pad or the like.

As an absorbent article such as menstrual sanitary napkins, an absorbent body including a front sheet, a back sheet, and an absorbent core containing a liquid retaining property between the two sheets is known, and is substantially long. Further, in the absorbent article having the above-described configuration, it is known that the excretory liquid such as menstrual blood is prevented from leaking to the outside of the excretory fluid, and the front sheet and the absorbent body are integrally recessed on the skin contact surface side. Made of leak-proof groove. For example, Patent Document 1 discloses an absorbent article in which a portion (center portion) including an absorbent body is thickened at a high portion on the skin contact surface side, and a leakage preventing groove is formed around the middle portion.

Further, Patent Document 2 discloses an absorbent body in an absorbent article, which is obtained by fixing a plurality of absorbent portions to each other on a single side of a base sheet including a stretchable sheet or the like. In the absorbent body described in Patent Document 2, an absorbent material is disposed between the adjacent absorbent portions at a basis weight lower than the absorbent portion. According to the absorbent article described in Patent Document 2, it is considered that the absorbent body including the above-described configuration is deformed in cooperation with the surface of the complex undulating skin, and is deformed in accordance with the movement of the wearer's body. The absorption retention of a higher liquid or the like can be achieved with or without deformation. Further, Patent Document 3 discloses that as an absorber in an absorbent article, a plurality of independent absorption portions are disposed in the planar direction. And fixing the absorbing portion to the intermediate sheet between the front sheet and the back sheet. The absorbent bodies described in Patent Documents 2 and 3 are common to each other, that is, a portion having a liquid absorbability (absorbent core) is divided into a plurality of regions (absorbent portions), and a plurality of absorbent portions. It is joined and fixed to the sheet by a joining means such as an adhesive.

Moreover, as an absorbent article such as a menstrual napkin, an absorbent body including a topsheet, a backsheet, and an absorbent core containing a liquid retaining property between the two sheets is known, and is substantially long. The applicant of the present invention has previously proposed an absorbent article comprising a back sheet comprising a moisture permeable sheet having a specific moisture permeability in order to effectively reduce the humidity in the garment when the absorbent article is used (see Patent Document 4). According to the absorbent article described in Patent Document 4, the humidity in the garment is effectively reduced, and the discomfort such as stuffiness and stickiness is less, and the texture is comfortable, so that it is less likely to cause skin troubles such as itching or rash.

Further, the applicant of the present invention has previously proposed an absorbent article comprising a plurality of compressed portions which are formed to be recessed from the front sheet side, in addition to an absorbent article comprising a back sheet having a specific moisture permeability. A body absorbent article (see Patent Document 5). According to the absorbent article described in Patent Document 5, the liquid repellency is excellent at the time of use, and the liquid does not remain on the surface, so that a dry and comfortable wearing feeling with a moist feeling can be imparted.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent No. 4167406

Patent Document 2: WO2010134456 A1

Patent Document 3: US2010262108 A1

Patent Document 4: EP0640328 A1

Patent Document 5: US2006041239 A1

As described in Patent Document 1, when a leakage preventing groove is formed in a general absorbent body in which the absorbent core is not divided into a plurality of regions, leakage prevention is improved by blocking the drainage liquid with the leakage preventing groove. The effect, on the other hand, is as follows: i) the excretion liquid tends to be locally retained, and the discomfort caused by the wearer's wetting cannot be eliminated, and ii) the high density is continuously formed in the absorbent body. The leakage preventing groove causes the absorbent body to be locally hardened, so that it is difficult to adhere to the wearer's body and the suitability is lowered.

Since the absorbent body described in Patent Documents 2 and 3 has a configuration in which the absorbent core is divided into a plurality of regions (absorbent portions), it is difficult to produce the above i) and ii), particularly the above-mentioned ii, as compared with a normal absorbent body. In the case of a problem, since a plurality of absorbing portions are joined and fixed to the sheet by a bonding means such as an adhesive, the absorbing portion and the sheet are integrally formed of the same material, for example, The excretion of the excretion is poor, and there is room for improvement in the diffusion and absorption of the excretion fluid combined with the leakage preventing groove. Therefore, in the absorbent article using the combination of the absorbent body and the leakage preventing groove described in Patent Documents 2 and 3, in particular, the blocking effect (side leakage preventing effect) of the drainage liquid by the leakage preventing groove has room for improvement, particularly In the case of a large amount of excretion at one time, there is a problem in that the excretion liquid moves on the abutting surface of the skin to reach the leakage preventing groove, and then passes over the leakage preventing groove to the absorbent article. The outside moves, causing side leakage.

As a method of preventing such side leakage caused by the movement of the excretion liquid over the leakage preventing groove, a method of arranging the absorbent body on the outer side of the absorbent article more than the leakage preventing groove is considered. For example, when a leakage preventing groove extending in the longitudinal direction of the absorbent article is formed, the absorbent body disposed in the width direction of the absorbent article is extended from the leakage preventing groove to the leakage preventing groove. The width of the absorbent article is outward. However, in this method, it is necessary to have an absorbent body having a certain size (width) of such an extended portion, so that it is difficult to narrow the size (width) of the absorbent body, and it is difficult to satisfy the recent demand, that is, to achieve absorption. The miniaturization of the articles makes the design of the products less flexible. The following absorbent article has not been provided, that is, the diffusion and absorption effects of the excretory fluid combined with the absorbent body and the leakage preventing groove are excellent, and the wearer's uncomfortable feeling due to wetting can be eliminated, and the suitability is also excellent.

Further, as described above, according to the absorbent article described in Patent Document 4, the humidity in the garment can be effectively reduced. However, in recent years, the humidity in the garment is more effectively reduced, and the moist feeling is further reduced, thereby providing more comfort. The demand for wearable absorbent articles continues to increase.

According to a first aspect of the invention, there is provided an absorbent article comprising: a front sheet disposed on a skin contact surface side; a back sheet disposed on a non-skin contact surface side; and an absorption between the two sheets An elongated absorbent article of the body; and the absorbent system comprises an absorbent core comprising an absorbent material comprising a relatively high basis weight portion of the absorbent material, and the absorbent material Relatively low base weight, the high basis weight The low basis weight portion is alternately formed in the longitudinal direction and the width direction of the absorbent article, and the absorbent sheet is formed with a groove in which the front sheet and the absorbent core are integrally recessed. Forming at least two of the high basis weight portions arranged in the longitudinal direction or the width direction and one of the low basis weight portions sandwiched by the two high basis weight portions; dividing the bottom of the groove The wall portion is located on the non-skin contact surface side in the center in the thickness direction of the absorbent core.

According to the absorbent article of the present invention (the first invention and the third invention), the excretion liquid can be quickly absorbed and diffused, and the wearer's uncomfortable feeling due to wetting can be eliminated.

Further, according to the absorbent article of the present invention (second invention), the excretion liquid can be quickly absorbed and diffused, and the wearer's discomfort caused by wetting can be eliminated, and although the leakage preventing groove is included, it is moderate. Excellent flexibility is obtained by the flexibility.

Moreover, according to the absorbent article of the fourth aspect of the invention, the humidity in the dress during use can be effectively reduced, and the moist feeling can be further reduced to provide a more comfortable wearing feeling.

The present invention (the first invention and the third invention) relates to an absorbent article which can quickly absorb and diffuse the excretion liquid, thereby eliminating the wearer's uncomfortable feeling due to wetting.

Further, the present invention (second invention) relates to a method of rapidly absorbing and diffusing excretion liquid, thereby eliminating the wearer's discomfort caused by wetting, and although An absorbent article that contains a leak-proof groove but still has moderate flexibility and is excellent in suitability.

Moreover, the present invention (fourth invention) provides an absorbent article which satisfies the above needs.

Hereinafter, a menstrual sanitary napkin which is one preferred embodiment of the absorbent article according to the present invention (first invention) will be described with reference to the drawings. As shown in FIG. 1 and FIG. 2, the sanitary napkin 1A of the present embodiment includes a front sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and two sheets. 2, 3 of the absorber 4A, and is longitudinal (long shape in one direction). As shown in Fig. 1, the sanitary napkin 1A includes, in the longitudinal direction X, the excretory portion opposing portion 11 disposed opposite to the wearer's excretory portion (vaginal opening) when worn, and disposed at the opposite excretory portion when worn. The portion 11 is further disposed on the front side portion 12 of the wearer's ventral side and the rear side portion 13 of the wearer's back portion 11 when worn. The excretory portion opposing portion 11 is a portion having a pair of side flap portions 6 and 6 on the right and left sides. The pair of side flap portions 6 and 6 are used to refasten the sanitary napkin 1A to the lower crotch portion (the crotch portion) of the undergarment when the sanitary napkin 1A is fixed to an undergarment or the like. In the case where the absorbent article (menstrual sanitary napkin) of the present invention (the first invention) does not have the side flap portion, the entire length of the menstrual portion of the excretion portion of the menstrual napkin is 25 cm or less in the longitudinal direction of the product. In the short-term daily sanitary napkin, the center portion (the second region from the front to the back) in the case where the sanitary napkin is divided into three equal parts in the longitudinal direction is the front portion, the center portion, and the rear portion. In the so-called long-term daily and night sanitary napkins with a total length of more than 25 cm, the second area from the front to the back of the sanitary cotton in the longitudinal direction is divided into four parts (from the rear to the rear) The third area before).

Further, in the present specification, the skin contact surface is the surface of the absorbent article or the constituent member facing the wearer's skin side when the absorbent article is worn, and the non-skin contact surface is an absorbent article or a member thereof. When facing the absorbent article, it faces the side opposite to the skin side (cloth side). Further, the longitudinal direction is along the longitudinal direction of the absorbent article or its constituent members, and the width direction is a direction orthogonal to the longitudinal direction. In the figure, the direction indicated by the symbol X is the longitudinal direction of the absorbent article (absorbent body or absorbent core), and the direction indicated by the symbol Y is the width direction of the absorbent article (absorbent body or absorbent core).

As shown in FIG. 2, the front sheet 2 covers the entire area of the skin contact surface 4a of the absorber 4A, and further extends from the left and right edges of the absorber 4A in the longitudinal direction X to the outside of the width direction Y. The back sheet 3 covers the entire area of the non-skin contact surface 4b of the absorber 4A, and further extends from the both side edges of the absorber 4A to the outside in the width direction Y. Further, the front sheet 2 and the back sheet 3 are also extended from the front end and the rear end of the longitudinal direction X of the absorber 4A to the outside of the longitudinal direction X, and by the adhesive, heat in the extensions Bonding, ultrasonic sealing, and the like are known to be joined to each other by means of a known joining means.

As shown in FIGS. 1 and 2, a pair of side sheets 5 and 5 are disposed over the entire length direction X of the sanitary napkin 1A on both sides of the sanitary napkin 1A in the longitudinal direction X. In the side sheet 5, the side portion on the inner side in the width direction Y is joined to the skin contact surface 2a of the front sheet 2 by a known joining means, and the side of the outer side is adhered to the side of the absorbent body 4A. The side edge of the longitudinal direction X extends beyond the width direction Y, and the extension thereof is by a known joining means. Engaged with the extension from the side edge of the absorbent body 4A in the back sheet 3. In the excretion portion opposing portion 11, the back sheet 3 and the side sheet 5 have the largest extension from the side edge of the absorber 4A in the width direction Y, and the pair of side portions are formed by the maximum extension portions. 6,6.

The non-skin contact surface of the sanitary napkin 1A (the non-skin contact surface 3b of the back sheet 3) is worn toward the garment side such as the crotch portion of the shorts. An adhesive portion (not shown) for fixing the sanitary napkin 1A to the crotch portion of the underwear such as a pair of shorts is provided on the non-skin contact surface 3b. Further, an adhesive portion for fixing to the outer surface of the shorts (non-skin contact surface) is provided on the non-skin contact surface (the non-skin contact surface 3b of the back sheet 3) of the pair of side flap portions 6 and 6 ( Not shown). These adhesive portions are provided by applying a hot-melt adhesive to a specific portion, and are covered with a release sheet (not shown) including a film, a nonwoven fabric, a paper, or the like before the use of the sanitary napkin 1A.

The absorber 4A is composed of an absorbent core 40A containing an absorbent material (a fibrous material such as pulp or a water-absorbent polymer). The absorber 4A in the present embodiment is configured by coating an absorbent core 40A with a packaged core material (not shown) including a tissue paper or a water-permeable nonwoven fabric. The absorbent core 40A may include only the fibrous material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42 described below, or may be composed of the fibrous material and the water-absorbing polymer, and the latter In a case, it may be a form in which a water-absorbent polymer is uniformly mixed between the fiber materials, or may be a fiber layer mainly composed of a fiber material and a polymer layer mainly composed of a water-absorbing polymer, and may be The polymer layer is sandwiched between the two layers of the fiber layer. Between the front sheet 2 and the absorber 4A, and between the absorber 4A and the back sheet 3 It can be bonded to each other by an adhesive (hot melt adhesive or the like) which is applied by patterning such as dots, spirals, and stripes.

As shown in FIGS. 2 and 3, the absorbent core 40A includes a relatively high basis weight portion 41 having a relatively large amount of absorbent material, and a low basis weight portion 42 (42X, 42Y) having a relatively small amount of absorbent material, and a high base. The heavy portion 41 and the low basis weight portion 42 are alternately formed in the longitudinal direction X and the width direction Y, respectively. More specifically, in the absorbent core 40A, as shown in FIG. 3, a plurality of linear low base portions 42X extending in the longitudinal direction X and linear low bases extending in the width direction Y are respectively formed. The heavy portion 42Y and the low basis weight portion 42 are formed in a lattice shape as a whole, and the portion defined by the linear low basis weight portions 42X and 42Y becomes the high basis weight portion 41. A plurality of linear low basis weight portions 42X are formed extending over the entire length X of the absorbent core 40A, and a plurality of linear low basis weight portions 42Y are respectively spread over the width direction of the absorbent core 40A. The full length extends to form. Each of the plurality of high basis weight portions 41 has a rectangular shape in plan view as shown in Fig. 3(a).

Further, in the present embodiment, as shown in FIG. 2, since the thickness of the outer shape of the absorbent core 40A is uniformly formed, the thickness of the high basis weight portion 41 is lower than that of the base portion 42 (42X, 42Y). The absorbent core 40A has a concave-convex structure in which the high basis weight portion 41 is raised by the lower basis weight portion 42. When the absorbent core 40A has a concavo-convex structure, it is easier to induce an absorbent core when wearing the sanitary napkin 1A than when the skin contact surface and the non-skin contact surface are not flat. The deformation of the body 40A (absorbent body 4A), specifically, is easily induced to deform into a shape such as the absorbent core 40A which is swelled toward the skin of the sanitary napkin wearer. It is easy to deform by such an absorbent core 40A When the sanitary napkin 1A is worn, it is easily deformed into a shape in which the excretory portion opposing portion 11 is pressed against the skin of the sanitary napkin wearer, thereby improving suitability, giving the wearer a comfortable wearing feeling, and effectively Suppress the leakage of menstrual blood.

When viewed in the cross section of the absorbent core 40A shown in Fig. 2, the low basis weight portions 42 (42X, 42Y) are biased to one side in the thickness direction of the absorbent core 40A. More specifically, in the present embodiment, as shown in FIG. 2, the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction T of the absorbent core 40A. Further, since the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction T, the high basis weight portion 41 protrudes toward the opposite side of the skin contact surface 4a, that is, in the thickness direction T. The non-skin abutting surface 4b protrudes. Therefore, in the absorbent core body 40A, the skin contact surface 4a (the surface facing the front sheet 2) is substantially flat except for the portion where the groove 7 is formed, and the other portions are substantially flat without unevenness (flat without unevenness). On the other hand, the non-skin contact surface 4b (the surface facing the back sheet 3) has a high basis weight portion 41 (convex portion) formed by protrusion and a low base between the high basis weight portions 41, 41. Concavities and convexities formed by the heavy portion 42 (non-convex portion or concave portion). When the low basis weight portion 42 of the absorbent core 40A is biased against the skin contact surface 4a side, as shown in FIG. 2, the non-skin contact surface 4b side is formed on the opposite side of the skin contact surface 4a side. Since the space portion (non-convex portion or concave portion) is not present due to the absence of the low basis weight portion 42, the absorbent core 40A is easily deformed so as to face the sanitary napkin as the base portion of the low base portion 42 on the skin abutting surface 4a side. Since the shape of the wearer's skin is raised, the effect of improving the fit or preventing the leakage of menstrual blood is exerted.

Furthermore, in the present invention (first invention), the thickness of the absorbent core 40A is The position of the lower base portion 42 (42X, 42Y) on the T is not limited to the skin contact surface 4a side as shown in FIG. 2, and may be, for example, the non-skin contact surface 4b side. . That is, when the absorbent core 40A is viewed in a cross section, the low basis weight portion 42 may be biased toward the non-skin contact surface 4b side in the thickness direction T of the absorbent core 40A. In this case, the high basis weight portion 41 protrudes toward the opposite side of the non-skin contact surface 4b side, that is, protrudes toward the skin contact surface 4a side in the thickness direction T, and the absorbent core 40A as a whole is in FIG. The one shown is the opposite. Therefore, in the absorbent core 40A in which the low basis weight portion 42 is biased against the non-skin contact surface 4b side, the non-skin contact surface 4b (the surface facing the back sheet 3) is substantially flat, as opposed to Here, the skin contact surface 4a (the surface facing the front sheet 2) has a high basis weight portion 41 (protrusion portion) formed by protrusion and a low basis weight portion 42 between the high basis weight portions 41, 41 (non- The unevenness formed by the convex portion or the concave portion forms a space portion (non-convex portion or concave portion) due to the absence of the low basis weight portion 42 on the skin contact surface 4a side. Since the space portion on the side of the skin contact surface 4a is formed so as to be sandwiched between the adjacent two high basis weight portions 41 and 41, it is easy to maintain the shape of the space portion when the sanitary napkin is worn. The space portion ventilates the air existing between the skin of the sanitary napkin wearer and the sanitary napkin 1A, and reduces the feeling of sultry felt by the wearer of the sanitary napkin.

Further, in the present invention (first invention), the low basis weight portion 42 (42X, 42Y) may be biased against the skin in the thickness direction T of the absorbent core 40A when viewed in a cross section of the absorbent core 40A. The abutting surface 4a and the non-skin contact surface 4b are substantially at the center. In this case, the high basis weight portion 41 protrudes toward the skin contact surface 4a side and the non-skin contact surface 4b side in the thickness direction T, respectively. Therefore, the low basis weight portion 42 is biased against the approximate center of the skin abutting surface 4a and the non-skin abutting surface 4b. In the absorbent core 40A, the skin abutting surface 4a and the non-skin abutting surface 4b respectively have a high basis weight portion 41 (protrusion portion) formed by protrusion and a low basis weight between the high basis weight portions 41, 41. The unevenness formed by the portion 42 (non-convex portion or concave portion) forms a space portion (non-convex portion or portion) due to the absence of the low basis weight portion 42 on the skin contact surface 4a side and the non-skin contact surface 4b side, respectively. Concave). The absorbent core body 40A of this type is easily deformed so as to be worn toward the sanitary napkin as the base shaft with the low basis weight portion 42 located at the substantially central portion of the thickness direction T (the substantially central portion of the outer thickness of the absorbent core 40A). The shape of the skin is raised, and the air portion between the skin of the sanitary napkin wearer and the sanitary napkin 1A is ventilated by the space portion.

As described above, in the present invention (first invention), the biasing position of the low basis weight portion 42 (42X, 42Y) in the thickness direction T of the absorbent core 40A can be caused by the biased position depending on the particular expectation. Which of the effects (deformation-inducing effect, ventilation effect) of the absorbent core 40A, and the skin contact surface 4a side, the non-skin contact surface 4b side, or the skin abutment surface as shown in Fig. 2 4a is appropriately selected from the substantially central portion of the non-skin contact surface 4b.

In the absorbent core 40A (the above-mentioned uneven structure) of the present embodiment, a plurality of absorbent portions having a rectangular shape in a plan view including an absorbent material are disposed apart from each other on one side of the absorbent material which is formed into a thin plate shape. In this respect, it may be similar to the absorbent body described in Patent Documents 2 and 3 (an absorbent body in which a plurality of absorbent portions are fixed to a sheet). However, the absorbent core 40A of the present embodiment differs from the absorbent bodies described in Patent Documents 2 and 3 in that the absorbent core 40A of the present embodiment is formed and absorbed in such a manner as to have the above-described uneven structure as described below. Material Further, the manufacturer, the high basis weight portion 41 and the low basis weight portion 42 are integrated without bonding means such as an adhesive or heat fusion, and do not have the boundary of the same material (high basis weight portion 41 and low basis weight portion). In contrast, in the absorption system described in Patent Documents 2 and 3, a plurality of the absorption portions are fixed to the sheet which is different from the absorption portion, and the absorption portion is the absorbent portion. The sheets are joined to each other via a joining means, and have a boundary between the absorbent portion and the sheet. In addition, the high basis weight portion 41 and the low basis weight portion 42 of the present embodiment have continuity in which the liquid can smoothly move, and the absorbent bodies described in Patent Documents 2 and 3 are in the absorbent body. In the above-mentioned absorbing portion and the above-mentioned sheet, since the interface including the bonding means exists between the two (boundary), the liquid in the boundary portion is likely to be diffused, and it is difficult to say that the liquid can smoothly move smoothly.

As shown in FIGS. 1 to 3, a groove 7 in which the front sheet 2 and the absorbent core 40A are integrally recessed is formed in the sanitary napkin 1A. The groove 7 is a space defined by the bottom wall portion 71 and the side wall portion 72 (the portion where the sanitary napkin 1A does not have a material to be formed). As shown in FIG. 3(a), the groove 7 includes one pair of longitudinal grooves 7X and 7X extending in the longitudinal direction X and two lateral grooves 7Y1 and 7Y2 extending continuously in the width direction Y. The four grooves are connected at their respective ends to form an annular groove as a whole. The pair of vertical grooves 7X and 7X extend over the entire length direction X of the absorbent portion opposing portion 11 in the longitudinal direction of the absorbent core 40A, and further extend to the front portion 12 and the rear portion, respectively. Part 13. The lateral groove 7Y1 and the lateral groove 7Y2 are formed in the front portion 12 and the rear portion 13, respectively. Any one of the two lateral grooves 7Y1 and 7Y2 is formed in a shape of a horizontally long curved shape which is convex outward in the longitudinal direction X in plan view. The top of each of the two lateral grooves 7Y1, 7Y2 is located at the center of the width direction Y.

The grooves 7 (7X, 7Y1, 7Y2) can be formed by a usual method by embossing with heat or embossing without heat or ultrasonic embossing. That is, in the manufacturing step of the sanitary napkin 1A, after the front sheet 2 is supplied to one surface of the absorbent body 4A (absorbent core 40A having the uneven structure), the specific portion is applied from the front sheet by embossing. The 2 side is pressed (compressed) in a concave shape toward the absorber 4A side, whereby the groove 7 can be formed at the specific portion. In the groove 7, the front sheet 2 and the absorber 4A are integrated by heat fusion or the like. The groove 7 can be a plurality of deep depressions (portions of relatively deep depressions, high pressure ripples) and shallow depressions (relatively shallow depressions, low pressure) of a rectangle, a square, a diamond, a circle, a cross, etc. in plan view. The ridges, which are alternately connected to each other, form a continuous line as a whole, or may be formed by arranging a plurality of depressed portions at intervals. The arrangement of the intervals means that the adjacent portions of the depressed portions are spaced apart by 5 mm or more.

The groove 7 is at least two high basis weight portions (protrusions) 41 and 41 arranged in the longitudinal direction X or the width direction Y, and one low base held by the two high basis weight portions 41 and 41. Heavy portions (non-protrusions or recesses) 42 are formed in series. That is, the groove 7 is formed so as to straddle the unevenness of the absorbent core 40A. In the present embodiment, as shown in FIG. 3(a), in the longitudinal direction X, the excretory portion opposing portion 11 which is a portion directly receiving the excretory liquid is one of the grooves 7 and the longitudinal grooves 7X and 7X. Formed by connecting two high basis weight portions 41, 41 adjacent in the longitudinal direction X and one low basis weight portion 42Y between the two, respectively, and absorbing the absorbent cores connected in the longitudinal direction X The concave and convex portions of the body 40A are formed. Further, regarding the width direction Y, in the front portion 12, as the groove 7 A part of the lateral grooves 7Y1 is formed by being connected to the two high basis weight portions 41 and 41 adjacent in the width direction Y and one low basis weight portion 42X located between the two, and further, in the rear portion 13, The lateral grooves 7Y2 which are a part of the grooves 7 are formed in the same manner.

The positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is more important in terms of the absorption and diffusion of the excretory liquid of the present invention (first invention), particularly as described above. In general, the groove 7 (longitudinal groove 7X) is formed so as to straddle the unevenness of the absorbent core 40A connected in the longitudinal direction X and the leakage of the excretory liquid caused by the movement of the excretory liquid in the width direction Y to the outside ( The so-called side leakage is related to the prevention effect, so it is more important. Therefore, in the present embodiment, as a configuration for more reliably obtaining the arrangement of the grooves 7 across the unevenness, the low basis weight portion 42 is included in the longitudinal direction X of the sanitary napkin 1A as described above. The linear portion 42X extending in the longitudinal direction X is formed, and the groove 7 is formed to include a portion 7X having a curved portion in a plan view and extending in the longitudinal direction X. In other words, in the present embodiment, the longitudinal grooves 7X and 7X are the lengths of the sanitary napkin 1A in the opposing portion 11 of the excretory portion as shown in Fig. 3(a) as one of the grooves 7. Each of the both side portions of the direction X includes a longitudinally curved shape that is convex outward in the width direction Y of the sanitary napkin 1A. In this manner, the low basis weight portion 42X of the absorbent core 40A is formed in a linear shape that completely coincides with the longitudinal direction X of the absorbent core 40A, and the vertical groove 7X is not completely aligned with the longitudinal direction X ( The curved portion is formed in a partially uniform manner, whereby at least the curved portion of the vertical groove 7X does not completely coincide with the linear low base portion 42X extending in the longitudinal direction X in plan view. Therefore, the longitudinal grooves 7X become easy to be formed so as to straddle the unevenness of the absorbent core 40A connected in the longitudinal direction X.

Further, in the present embodiment, the low basis weight portion 42 is formed so as to include the linear portion 42Y extending in the width direction Y in a plan view as described above. The groove 7 is formed to include portions 7Y1 and 7Y2 having a curved portion in a plan view and extending in the width direction Y. In other words, in the present embodiment, the lateral grooves 7Y1 and 7Y2 which are a part of the groove 7 are respectively oriented toward the sanitary napkin in the front portion 12 or the rear portion 13 of the sanitary napkin 1A as shown in Fig. 3(a) in plan view. In the longitudinal direction X of the 1A, the shape of the horizontally curved shape is convex, whereby at least the curved portions of the lateral grooves 7Y1 and 7Y2 are not linearly lower than the linear basis portion 42Y extending in the width direction Y in plan view. It is completely uniform, so that the lateral grooves 7Y1, 7Y2 become easy to be formed so as to straddle the unevenness of the absorbent core 40A connected in the width direction Y.

The cross section of the groove 7 in each portion of the absorbent core 40A is schematically shown in Figs. 4 to 6 . As shown in FIGS. 4 to 6, the grooves 7 (7X, 7Y1, and 7Y2) are defined by the bottom wall portion 71 and the side wall portion 72 that is erected from the bottom wall portion 71. As shown in FIGS. 5 and 6, the bottom wall portion 71 of the partitioning groove 7 is located at the center Tc of the thickness direction of the absorbent core 40A in either of the high basis weight portion 41 and the low basis weight portion 42. The non-skin abutting surface 4b side. When the absorbent core 40A has a concavo-convex structure as in the present embodiment, the thickness center Tc is the center of the outer thickness of the absorbent core 40A having the uneven structure, and is located in the skin of the absorbent core 40A. The abutting surface 4a is in the middle of a portion that protrudes toward the non-skin contact surface 4b side. Furthermore, the absorbent core 40A does not have a concave-convex structure In the case where the thickness direction center Tc is the center of the substantial thickness of the absorbent core 40A, the absorbent core 40A is located between the skin contact surface 4a and the non-skin contact surface 4b.

When the bottom wall portion 71 of the dividing groove 7 is located on the non-skin contact surface 4b side in the thickness direction center Tc, the skin of the self-absorbent core 40A is abutted when the groove 7 is formed. When the surface 4a is compressed, 1) in the high basis weight portion 41, the portion which becomes the bottom wall portion 71 of the partition groove 7 after the above-described compression and the portion which becomes the side wall portion 72 are respectively compressed to stabilize the shape of the groove 7. 2) In the low basis weight portion 42, the low basis weight portion 42 is deformed in cooperation with the shape of the groove 7 from the skin contact surface 4a side by the above-described compression, thereby making the low basis weight portion 42 partial. Elongation. Further, the groove 7 obtained after the compression, that is, the bottom wall portion 71 is located in the groove 7 of the non-skin contact surface 4b side in the center Tc in the thickness direction in the high basis weight portion 41, since the shape of the groove 7 is stable, The suction property of the liquid by the capillary force is increased, and in the low basis weight portion 42, since the thickness of the groove 7 is increased, the amount of diffusion of the liquid is lowered, whereby the groove 7 (mainly the side wall portion 72) In the liquid, the liquid becomes easy to move to the high basis weight portion 41. It is preferable that the bottom wall portion 71 of the partition groove 7 is spaced apart from the center of the thickness direction Tc by 0.1 mm or more from the side in the thickness direction to the side of the non-skin contact surface 4b, and it is particularly preferable to exist. At a distance of 0.2 mm or more.

Basically, the bottom wall portion 71 of the dividing groove 7 is located closer to the non-skin abutting surface 4b than the center Tc of the thickness of the absorbent core 40A by adjusting the compressive force or the like when the groove 7 is formed, but by design The configuration of the absorbent core 40A makes it more sure that the bottom wall portion 71 is located in the center of the thickness direction of the absorbent core 40A. Tc is more dependent on the non-skin abutting surface 4b side. As described above, when the groove 7 is formed by collectively compressing the absorbent core 40A and the front sheet 2, there is a tendency that, in particular, the portion where the thickness of the low basis weight portion 42 is relatively thin is as described above. As described above, the groove 7 is formed so as to straddle the unevenness of the absorbent core 40A, whereby the degree of compression can be suppressed lower than that of the high basis weight portion 41, and the volume can be restored to some extent after the compression. Further, in the high basis weight portion 41, when the groove 7 is formed, it is relatively easily maintained by compressing from the portion which becomes the bottom wall portion 71 of the groove 7 to the portion which becomes the side wall portion 72 after the compression. In the state of the shape of the groove 7, the portion of the low basis weight portion 42 that is compressed by the formation of the groove 7 is the bottom wall portion 71 and its periphery, and the portion that is compressed is higher than the base portion 41. The volume of the compressed portion after compression is easy to recover. Therefore, there is a case where the bottom wall portion 71 of the groove 7 formed by the compression is located closer to the non-skin contact surface 4b side in the thickness direction center Tc even after the compression, which may result in the passage of time. When the volume is restored, the bottom wall portion 71 is moved toward the skin contact surface 4a side, and finally, in the low basis weight portion 42, the bottom wall portion 71 is located closer to the skin contact surface 4a side in the thickness direction center Tc. In order to prevent this, the bottom wall portion 71 of the dividing groove 7 is surely located closer to the non-skin abutting surface 4b side than the center portion Tc in the thickness direction, not only in the high basis weight portion 41 but also in the low basis weight portion 42. It is effective that the width L1 of the groove 7 across the low basis weight portion 42 (see FIG. 3), that is, the linear low base portion 42 (42X, 42Y) is not too long. By shortening the width L1 of the low basis weight portion 42 to some extent, the volume recovery of the compressed low basis weight portion 42 for forming the groove 7 is suppressed, so that the bottom wall portion 71 of the dividing groove 7 is more sure. The ground is located on the side of the non-skin abutting surface 4b in the center Tc in the thickness direction. In this view The width L1 of the low basis weight portion 42 is preferably 1 to 5 mm, more preferably 1 to 3 mm. In the low basis weight portions 42X and 42Y, the width L1 may be the same or different.

Further, in the case where the groove 7 is formed by alternately connecting the deep depressed portion and the shallow depressed portion as described above, the absorbent core 40A is compressed in such a manner that the deep depressed portion of the groove 7 is formed only in the low basis weight portion 42. Then, the volume of the compressed portion is difficult to recover after compression, so that it is difficult to obtain the above effect. Therefore, in order to surely obtain the above-described effects, it is effective to lengthen the length X of the sanitary napkin 1A of the deep depressed portion to be longer than the width L1 of the linear lower base portions 42 (42X, 42Y). In addition to the above methods, a more effective method is to incline the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 are extended) with respect to the direction in which the low basis weights are formed (the direction in which the linear low-weight portions extend). A specific angle is attached between the two forming directions).

In the present embodiment, in the high basis weight portion 41, the low basis weight portion 42, and the groove 7 and the vicinity thereof, the density of the high basis weight portion 41 is set to be higher than the density of the lower basis weight portion 42, and the groove 7 is formed. Thereby there is a density gradient. That is, in FIG. 3(b) and FIG. 4 to FIG. 6, the density of the portion indicated by the symbols A to E is A≦B<<C<<E, and more preferably A<B<<C<D<E. The further the distance from the groove 7 (the longitudinal groove 7X) is, the lower the density (the portion A), and the closer the groove 7 is, the higher the density becomes (the portion B and/or C), and the groove 7 (the bottom wall portion 71) The medium density reaches the maximum (parts D and E). Further, with respect to the groove 7 (bottom wall portion 71), the portion D in the low basis weight portion 42 (42Y) increases the diffusibility of the liquid along the groove 7 by the density slightly lower than the portion E in the high basis weight portion 41 ( The side leakage preventing effect) is preferably higher in the vicinity of the groove 7 in the base portion 41 having a higher density, that is, the portion C. The closer to the groove 7, the higher the density becomes, the density gradient is mainly The groove 7 (compression of the absorbent core 40A) is formed by the embossing described above, and is also present in the absorbent body previously formed with the leakage preventing groove. Regarding the density gradient, in the characteristic aspect of the present embodiment, the density of the portion C is higher than the portion B (B<<C), and the density in the vicinity of the groove 7 is in the high basis weight portion 41 and the low basis weight portion 42. Different situations. In addition, the "near vicinity of the groove" means the side wall portion 72 (see FIGS. 4 to 6) of the groove 7 and its vicinity, and mainly refers to the groove 7 (the outer surface of the side wall portion 72) to the length of the groove 7. A portion within 5 mm of the direction orthogonal to the direction (the width direction of the groove 7).

Thus, the vicinity of the groove 7 (longitudinal groove 7X), that is, the portions B and C are the same distance from the groove 7, but the density of the portion C located at the high basis weight portion 41 is higher than the portion B located at the low basis weight portion 42 (42Y). The reason is that before the groove 7 is formed by compressing the absorbent core 40A, the higher basis weight portion 41 has more absorbent material in the lower basis weight portion 42 and has a higher density. In the absorbent core 40A of the present embodiment, the absorbent material is deposited so as to include the high basis weight portion 41 and the low basis weight portion 42 as follows, and the deposit having the uneven structure is obtained. When the pressure roller or the like compresses the entire deposit by a uniform compressive force, the high basis weight portion 41 as the convex portion is stronger than the low basis weight portion 42 which is the non-convex portion or the concave portion in the above-described compression step. Since the density of the high basis weight portion 41 (the portion C) is low, the basis weight portion 42 (the portion B) is high. Thus, there is a difference in density before the formation of the groove 7 in the portion B and the portion C, and if the groove 7 is formed by compressing the portion B and the portion C, the density is reflected in the side wall portion 72 of the dividing groove 7 and its vicinity. The result is that B<<C with respect to density.

In the sanitary napkin 1A of the present embodiment, as an absorbent core forming the groove 7 The body adopts an absorbent core 40A having a concave-convex structure formed of a high basis weight portion (protrusion portion) 41 and a low basis weight portion (non-convex portion or concave portion) 42, thereby solving the previous flatness without unevenness The above problem ii) of the absorbent article in which the absorbent core and the leakage preventing groove are combined, and the high-density groove 7 is formed in the absorbent body 4A (absorbent core 40A), but the absorbent body 4A is still It is difficult to produce localized hardening and is excellent in suitability. Further, as shown in FIG. 3, if the low basis weight portion 42 is formed outside the sanitary napkin 1A (the outer portion of the groove 7) than the groove 7, the leakage preventing effect of the groove 7 can be further improved, and A soft touch is imparted to the peripheral portion of the sanitary napkin 1A (particularly, the side edges of the sanitary napkin 1A along the longitudinal direction X). Further, as shown in FIG. 3, when the high basis weight portion 41 is disposed on the entire portion of the absorbent core 40A surrounded by the low basis weight portion 42, the wearer touches when the sanitary napkin 1A is worn. The touch becomes soft and provides a soft touch.

Further, in the sanitary napkin 1A of the present embodiment, the groove 7 is mainly formed by connecting two high basis weight portions 41 and 41 adjacent in a specific direction and one low basis weight portion 42 located therebetween, and It is formed so as to straddle the concavities and convexities of the absorbent core 40A, whereby the amount of the excretory fluid such as menstrual blood can be quickly absorbed and diffused, thereby solving the previous flatness without unevenness. In the above-mentioned problem i) of the absorbent article in which the absorbent core and the leakage preventing groove are combined, the leakage prevention property (side leakage prevention property) is excellent, and the size of the absorbent body can be reduced, and the absorbent article can be downsized.

When the absorption and diffusion action of the excretory fluid in the sanitary napkin 1A of the present embodiment is described with reference to Fig. 3 (b), the excretion fluid W such as menstrual blood excreted by the wearer of the sanitary napkin 1A is usually opposed by the excretory portion. The width direction Y of the portion 11 The central portion is caught and moved from the skin abutting surface (the skin abutting surface 2a of the front sheet 2) toward the groove 7 (longitudinal groove 7X) in the width direction Y, for example, in FIG. 3(b), The portion A (near the center portion in the width direction Y of the excretion portion opposing portion 11) faces the portion B (near the groove 7 in the low basis weight portion 42) along the various constituent members of the sanitary napkin 1A (front sheet 2) The absorbent core 40A, etc.) moves. As described above, since the density difference is B<<C in the portion B and the portion C, the excretion liquid W reaching the portion B is easily moved to the vicinity of the groove 7 in the high basis weight portion 41 by capillary force. The portion C is not easily retained in the portion B. In this manner, the excretory fluid W moves in the vicinity of the groove 7 and in the width direction Y of the groove 7, and moves along the groove 7 in the front-rear direction of the sanitary napkin 1A, so that the opposite portion 11 from the excretory portion is promptly elongated in the longitudinal direction X. Diffusion.

The portion B is not only a gap (space) between the adjacent high basis weight portions 41, 41, but also exists as a part of the absorbent core 40A (low basis weight portion 42), and thus has a function of retaining the excretion liquid. Therefore, even when the amount of the excretory fluid W is large and the moving speed of the excretory fluid W from the portion A to the portion B is faster than the moving speed of the excretory fluid W from the portion B to the portion C (the diffusion speed in the longitudinal direction X) Further, the excretion liquid can be temporarily held at the portion B, and therefore, a large amount of the excretion liquid is prevented from simultaneously moving to the portion D (the lower basis weight portion 42 which is located outside the width direction Y of the sanitary napkin 1A at the portion B). The bottom wall portion 71) of the groove 7 is partitioned, and further, the excretion liquid W is prevented from moving beyond the groove 7 to the outside of the width direction Y of the sanitary napkin 1A to cause side leakage. Further, the portion B itself is relatively high in density when the groove 7 is formed, and the movement of the liquid from the portion B to the portion D is also suppressed, thereby contributing to prevention of side leakage.

The excretion liquid W is in the vicinity of the groove 7 and is more inward than the groove 7 in the width direction Y. In the middle of the movement from the portion B to the portion C, the high basis weight portion 41 is quickly absorbed and held, and the portion exceeding the absorption capacity of the high basis weight portion 41 is moved to the width direction of the portion C as shown in FIG. A portion E outside the Y (the bottom wall portion 71 of the dividing groove 7 in the high basis weight portion 41). The portion E is a portion that is most compressed when the groove 7 is formed, and since the density is much higher than the portion C adjacent in the width direction Y, the excretion liquid W is hard to move from the portion E to the portion C, so that it is difficult to cause excretion. The liquid W moves over the groove 7 and moves to the outside of the width direction Y of the sanitary napkin 1A. This is the same as the relationship between the portion B and the portion D in the low basis weight portion 42 described above. The excretion liquid W that has moved to the portion E via the portion C does not leak to the outer side of the groove 7, but moves to the adjacent portion D (the bottom wall portion 71 of the dividing groove 7 in the low basis weight portion 42) through the groove 7, and further , move to another part E adjacent to it. Thus, the excretory fluid W moving in the tank 7 is mainly absorbed and held by the high basis weight portion 41 during its movement.

In the sanitary napkin 1A of the present embodiment, the excretion liquid discharged to the central portion in the width direction Y of the excretion portion opposing portion 11 is in the vicinity of the vertical groove 7X and the vertical groove 7X and is located further in the width than the vertical groove 7X. Both of the portions in the direction Y are rapidly diffused in the front and rear directions of the sanitary napkin 1A, and are rapidly absorbed and held mainly by the high basis weight portion 41 in the middle of the above diffusion. Therefore, the sanitary napkin 1A of the present embodiment can rapidly diffuse the excreted excretion by utilizing the diffusion and absorption of the excretion fluid in combination with the absorbent body 4A (absorbent core 40A) and the groove 7. It is absorbed, so that it is difficult to produce side leakage, and the wearer's discomfort caused by wetting can be eliminated. From the viewpoint of more effectively exerting the effect of the sanitary napkin 1A, it is preferable to set the size and the like of each portion as follows.

The ratio (S41/S42) of the basis weight S41 of the high basis weight portion 41 of the absorbent core 40A to the basis weight S42 of the low basis weight portion 42 is preferably 1.25 or more, more preferably 3 or more, and more preferably 10 Hereinafter, it is more preferably 6 or less.

The basis weight S41 of the high basis weight portion 41 is preferably 100 g/m ² or more, more preferably 150 g/m ² or more, and further preferably 600 g/m ² or less, more preferably 500 g/m ² or less. The basis weight S42 of the low basis weight portion 42 is preferably 10 g/m ² or more, more preferably 30 g/m ² or more, and further preferably 150 g/m ² or less, more preferably 100 g/m ^{2 .} the following.

The ratio (T41/T42) of the thickness T41 of the high basis weight portion 41 to the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and is preferably 20 or less, more preferably 10 or less.

The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and further preferably 10 mm or less, more preferably 8 mm or less, and the thickness T42 of the low basis weight portion 42 is preferably 0.1. More than mm, more preferably 0.2 mm or more, and further preferably 5 mm or less, more preferably 3 mm or less.

The size of the high basis weight portion 41 as shown in Fig. 3(a) is different depending on the type and use of the absorbent article, and the length L2 in the longitudinal direction X in the sanitary napkin such as the sanitary napkin 1A (refer to 3(a)) is preferably 5 mm or more, more preferably 10 mm or more, and more preferably 50 mm or less, more preferably 30 mm or less, and a length L3 in the width direction Y (refer to Fig. 3 (a)) It is preferably 3 mm or more, more preferably 5 mm or more, and more preferably 30 mm or less, more preferably 20 mm or less.

Preferably, the area of the high basis weight portion 41 is preferably 5 or more, more preferably 10 or more, per 50 cm ² , and more preferably 70 or less, more preferably 60 or less.

The width L5 (see Fig. 3(b)) of the grooves 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and is preferably 5.0 mm or less, more preferably 4.0 mm or less.

The depth L6 (refer to FIG. 5) of the groove 7 is preferably 0.5 mm or more, and more preferably 1.0 mm or more.

Further, the size of each portion of the groove 7 may be measured by a ruler or the like using a ruler or the like, but it is preferably measured using a digital microscope (Digital Microscope). For example, the groove 7 can be enlarged and photographed using a digital microscope VHX-1000 manufactured by KEYENCE, and the size of each portion can be measured. The width L5 of the groove 7 is measured on the bottom surface of the groove 7. Further, the depth L6 of the strip groove 7 is obtained by measuring the cross section of the groove 7 by a digital microscope.

When the materials for forming the respective portions of the sanitary napkin 1A are described, the front sheet 2 and the back sheet 3 can be used without any particular limitation, and various materials previously used in the technical field can be used. As the front sheet 2, for example, a liquid permeable sheet such as a non-woven fabric or an apertured film can be used. As the back surface sheet 3, for example, a resin film which does not have moisture permeability, a resin film which has fine pores and has moisture permeability, a nonwoven fabric such as water-repellent nonwoven fabric, a laminate of these and other sheets, or the like can be used. Further, as the side sheet 5, various materials previously used in the technical field can be used without particular limitation, and for example, a water-repellent non-woven fabric or a resin film-made sheet can be used.

As the absorbent material which is a material for forming the absorbent core 40A, various materials previously used in the technical field can be used without particular limitation, for example. As the fiber material, natural fibers such as wood pulp, cotton, and hemp; composite fibers containing synthetic resins such as polyethylene or polypropylene; semi-synthetic fibers such as acetate or rayon, and the like can be used. Further, as the absorbent material, in addition to the fibrous materials, various shapes of water-absorbent polymers such as pellets may be used.

In the method for producing an absorbent body (absorbent core) of the present invention (first invention), a method for producing the absorbent body 4A (absorbent core 40A) will be described as an example. Fig. 7 shows an embodiment of the manufacturing method of the absorbent body 4A and a manufacturing apparatus used in the embodiment. The manufacturing apparatus of the absorber includes a rotating cylinder 50 that is rotationally driven in the direction of the arrow R1, a duct 60 that supplies the absorbent material 45, which is a raw material of the absorbent core 40A, to the outer peripheral surface of the rotating cylinder 50, and is disposed obliquely below the rotating cylinder 50. And a transfer roller 70 that is driven to rotate in the direction of the arrow R2, a vacuum box 65 disposed between the duct 60 and the transfer roller 70 in the circumferential direction of the rotary cylinder 50, to pass through the vacuum box 65 and rotate A mesh belt 75 which is disposed between the cylinders 50 and between the transfer roller 70 and the rotary cylinder 50 as a sheet-like gas permeable member, and a vacuum conveyer 80 disposed below the transfer roller 70.

As shown in Fig. 7, the rotary cylinder 50 is formed in a cylindrical shape, receives power from a prime mover such as a motor, and rotates a member forming an outer peripheral surface thereof around a horizontal axis. A non-rotating portion on the inner side (rotational axis side) of the rotary cylinder 50 is formed with a space 56 for decompressing the inside. A known exhaust device (not shown) such as an intake fan is connected to the space 56, and by operating the exhaust device, the space 56 can be maintained at a negative pressure. On the other hand, a space for the air outside the device is connected to the spaces 57 and 58 on the inner side (rotational axis side) of the rotary cylinder 50 (not Graphic).

As shown in FIG. 8, a concave portion 51 having a shape corresponding to the shape of the manufactured absorbent core 40A is formed on the outer peripheral surface of the rotary cylinder 50. A plurality of micropores are formed in the bottom surface portion 52 of the concave portion 51. The micropores of the bottom surface portion 52 of the concave portion 51 function as suction holes of the absorbent material 45 while the concave portion 51 is maintained in the space 56 for negative pressure. On the other hand, the left and right side portions of the outer circumferential surface of the rotary cylinder 50 in which the concave portion 51 is not formed include a casing including a rotating cylinder 50 made of a metal rigid body, and is non-breathable.

As shown in FIG. 8, a plurality of partitioning members 53 that divide the inside of the recessed portion 51 into a plurality of regions are formed in the bottom surface portion 52 of the recessed portion 51. Each of the dividing members 53 includes a plate member that is not gas permeable. The inside of the recess 51 is divided into a plurality of regions 54 corresponding to the plurality of high basis weight portions 41 of the absorbent core 40A by a plurality of dividing members 53. The shape of each of the divided regions 54 in plan view is the same shape (rectangular shape) as the shape of the high basis weight portion 41 in plan view. Further, as described below, since the absorbent material is deposited in the concave portion 51 beyond the protruding height of the partitioning member 53 from the bottom surface portion 52, the protruding height of the dividing member 53 from the bottom surface portion 52 is shorter than the depth of the concave portion 51.

As shown in Fig. 7, the duct 60 has one end side covering the outer peripheral surface of the rotating cylinder 50 in the space 56 maintained in the negative pressure, and has a fiber material introducing device on the other end side (not shown). The fiber material introduction device includes a pulverizer that pulverizes, for example, a sheet-like wood pulp as a defibrated pulp, and feeds the defibrated pulp (fiber material) into the catheter. A water-absorbent polymer introduction portion into which the water-absorbent polymer is introduced may be provided in the middle of the conduit 60.

The transfer roller 70 includes a cylindrical outer peripheral portion having gas permeability and is received From the motive of the prime mover such as a motor, the outer peripheral portion is rotated about the horizontal axis. A non-rotating portion on the inner side (rotational axis side) of the transfer roller 70 is formed with a space 71 for decompressing the inside. A known exhaust device (not shown) such as an intake fan is connected to the space 71, and by operating the exhaust device, the space 71 can be maintained at a negative pressure.

The vacuum box 65 is disposed between the downstream end portion 61 of the duct 60 and the transfer roller 70 in the rotation direction R1 of the rotary cylinder 50. The vacuum box 65 has a box shape including upper and lower surfaces, right and left side surfaces, and a back surface, and has an opening portion that opens toward the rotating cylinder 50 at a portion facing the back surface. The vacuum box 65 is connected to a known exhaust device (not shown) such as an intake fan via the exhaust pipe 61, and the inside of the vacuum box 65 can be maintained at a negative pressure by the operation of the exhaust device.

The mesh belt 75 is a sheet-shaped gas permeable member, and is formed by a belt-shaped gas permeable belt having a mesh shape, and is guided by a plurality of free rollers and transfer rollers 70 to continuously move on a specific path. . The mesh belt 75 is driven by the rotation of the transfer roller 70. The mesh belt 75 is disposed in such a manner as to be introduced into the outer circumferential surface of the rotary cylinder 50 near the downstream end portion 61 of the duct 60, and sequentially passes between the vacuum box 65 and the rotary cylinder 50, and as shown in FIG. The transfer roller 70 is between the rotating drum 50. The mesh belt 75 is in contact with the outer peripheral surface of the rotary cylinder 50 before passing through the opening of the vacuum chamber 65, and is separated from the outer peripheral surface of the rotary cylinder 50 by the vicinity of the closest portion of the transfer roller 70 and the rotary cylinder 50. Transfer on the roll 70.

The vacuum conveyor 80 includes an annular gas permeable belt 83 that is stretched over the driving roller 81 and the driven roller 82, and a gas permeable belt 83 that is disposed to face the transfer roller 70. Vacuum box 84 at the location.

Next, a method of continuously producing the absorbent body 4A (absorbent core 40A) using the above-described manufacturing apparatus of the absorbent body will be described. In order to manufacture the absorber 4A using the above-described manufacturing apparatus of the absorbent body, the space 56 connected to the inside of the rotary cylinder 50 and the exhaust apparatus in the vacuum tank 65 are actuated to make the space 56 and the inside of the vacuum chamber 65 a negative pressure. By causing the inside of the space 56 to be a negative pressure, an air flow for transporting the absorbent material 45 to the outer peripheral surface of the rotary cylinder 50 is generated in the duct 60. Further, the rotary cylinder 50 and the transfer roller 70 are rotated, and the vacuum conveyor 80 is operated. Then, when the fiber material introduction device is actuated to supply the fiber material into the duct 60 and further the water-absorbent polymer is supplied, the absorbent material 45 rides on the airflow flowing in the duct 60, and becomes scattered and oriented. The outer circumference of the rotary cylinder 50 is supplied.

The absorbent material (mixture of the fibrous material and the water-absorbing polymer) 45 is sucked into the concave portion 51 of the rotary cylinder 50 during the conveyance of the portion covered by the conduit 60. The absorbent material 45 is gradually deposited on the bottom surface portion 52 of each of the divided regions 54 of the concave portion 51, and finally accumulates in the concave portion 51 beyond the protruding height of the partitioning member 53 from the bottom surface portion 52 as shown in FIG. In the deposit 46 obtained in this manner, the amount of the absorbent material 45 in the portion (the partitioning member corresponding portion) 46a in which the absorbent material 45 is deposited on the partitioning member 53 is relatively small, and the other portions (the divided portion corresponding portions) The amount of the absorbent material 45 of 46b is relatively large, so that the deposit 46 has a concavo-convex structure as a whole.

Then, when the rotary cylinder 50 rotates to rotate the concave portion 51 to the opposite position of the vacuum box 65, the deposit 46 in the concave portion 51 becomes adsorbed to the mesh belt 75 by suction from the vacuum box 65. . Deposits 46 in the recess 51 In this state, it is conveyed to a position immediately before the closest portion of the transfer roller 70 and the rotary cylinder 50, and in the vicinity of the closest portion, the state of being adsorbed to the mesh belt 75 is maintained by suction from the transfer roller 70 side. The concave portion 51 is released from the mold to be transferred to the transfer roller 70.

Thus, the deposit 46 transferred to the transfer roller 70 together with the mesh belt 75 is held in the state of the mesh belt 75 adsorbed on the transfer roller 70, and is transported to the interface with the vacuum conveyor 80 (the most of the transfer roller 70) The lower end portion is transferred to the vacuum conveyor 80 by the suction of the vacuum box 84 at the delivery portion.

In the apparatus for manufacturing an absorbent body according to the present embodiment, as shown in FIG. 7, the first package of the core material 47 including the toilet paper or the water-permeable nonwoven fabric is introduced onto the vacuum conveyor 80 before the deposit 46 is placed, so that the deposit 46 is deposited. Transfer to the first package of the chip material 47. Then, after the second package of the core material 48 is introduced onto the upper surface side of the deposit 46, the deposit 46 in a state covered by the two packages of the core materials 47 and 48 is cut at a predetermined interval to obtain a cut into An absorbent precursor 49 equivalent to the size of one sanitary napkin. Furthermore, the illustration of the two-package core materials 47, 48 is omitted in FIGS. 1 and 2.

Then, in the apparatus for manufacturing an absorbent body according to the present embodiment, the absorber precursor 49 thus obtained is compressed by the pressurizing mechanism 90, and the thickness of the deposit 46 constituting the absorber precursor 49 is actively reduced. Thereby, the target absorbent body 4A (absorbent core 40A) is obtained. As shown in Fig. 7, the pressurizing mechanism 90 is configured to include a surface smoothing pair of rollers 91, 92, and pressurizes the pressed object introduced between the rollers 91, 92 from the upper and lower surfaces in the thickness direction. Its compression.

The state of the deposit 46 before and after compression is schematically shown in FIG. Separate The arrow on the left side of Fig. 10 shows the deposit 46 before compression, the figure on the right side shows the pile 46 after compression (absorbent core 40A), and in the left and right figures, the upper part shows the deposit 46 (absorption) A cross-sectional view of the core 40A), and a lower view of the deposit 46. When the deposit 46 is compressed by the pressurizing mechanism 90, the partitioning portion corresponding portion 46b (the convex portion) having a relatively large amount of the absorbent material and having a relatively large thickness is smaller than the absorbent member and the partitioning member corresponding portion 46a having a small thickness. (non-protrusions or recesses) are subject to stronger compression. As a result, the divided region corresponding portion 46b in the deposit 46 becomes a high basis weight portion 41 having a relatively high density in the absorbent core 40A, and the partition member corresponding portion 46a in the deposit 46 becomes a density in the absorbent core 40A. Lower low basis weight 42.

According to the method for producing an absorbent body, it is possible to efficiently produce a high basis weight portion 41 having a relatively high density and a low basis weight portion 42 having a relatively low density alternately formed in both the longitudinal direction X and the width direction Y. The absorptive core 40A of the uneven structure. The ratio (D41/D42) of the density D41 of the high basis weight portion 41 to the density D42 of the low basis weight portion 42 is preferably from 1.5 to 20, more preferably from 2.0 to 10. The density of the high basis weight portion 41 and the low basis weight portion 42 was measured as follows.

<Method for measuring density>

The density of the high basis weight portion 41 is calculated by dividing the weight of the high basis weight portion 41 by the volume (thickness × length × width) of the high basis weight portion 41. The density of the low basis weight portion 42 is calculated by dividing the weight of the low basis weight portion 42 by the volume (thickness x length x width) of the low basis weight portion 42. The "thickness" used in the calculation of the volume of each of the high basis weight portion 41 and the low basis weight portion 42 is measured as follows. An acrylic plate having a length of 37 mm, a width of 37 mm, and a thickness of 3 mm was placed on the absorbent core 40A of the measurement object, and the high basis weight portion 41 of the absorbent core 40A was placed. The thickness was measured using a non-contact laser displacement meter (laser head LK-G30, displacement meter LK-GD500) manufactured by KEYENCE Corporation, and the thickness of the low basis weight portion 42 was obtained by using a microscope VHX- manufactured by KEYENCE Corporation. The cross section of the absorbent core 40A (the cross section shown in Fig. 2) was observed and measured. Moreover, the "weight" of each of the high basis weight portion 41 and the low basis weight portion 42 is measured as follows. The razor (feather razor S single blade) manufactured by FEATHER Co., Ltd. is pressed against the absorbent core 40A to be measured, and the high basis weight portion 41 and the low basis weight portion 42 are cut out, respectively, and an electronic balance (manufactured by A & D Co., Ltd.) is used. The electronic balance GR-300, accuracy: 4 digits after the decimal point) measures the weight of each of the cut high basis weight portion 41 and the low basis weight portion 42.

The present invention (first invention) is not limited to the above embodiment. For example, in the above-described embodiment, the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction of the absorbent core 40A, but as described above, it may instead be biased against the non-skin resistance. The joint surface 4b side may be biased against the substantially central portion of the skin contact surface 4a and the non-skin contact surface 4b. When the low basis weight portion 42 is biased against the non-skin contact surface 4b in the thickness direction of the absorbent core 40A, the non-skin abutting surface 4b is substantially absent when viewed in the cross section of the absorbent core 40A. It is flat and flat (flat and without unevenness).

Further, the low basis weight portions 42 (42X, 42Y) which are linear in plan view may not be formed on the entire absorbent core 40A as shown in FIG. 3 (to span the front portion 12, the discharge portion facing portion 11 and the rear portion). The portion 13 is formed as long as it is formed in at least a pair of grooves 7, 7 (longitudinal grooves 7X, 7X) and a vicinity (slot peripheral region) of the excretion portion opposing portion 11 (excretion portion pair) The inner portion of the width direction of the portion 11 may be used. Moreover, the top shape of the low basis weight portion 42 is not the same as above The embodiment is limited to a straight line as in the embodiment, and may be curved.

Further, in the absorbent core 40A, the high basis weight portion 41 may be arranged in a zigzag shape. In other words, a plurality of high basis weight portions 41 are arranged at a predetermined interval in the longitudinal direction X to form a high basis weight portion row, and a plurality of the high basis weight portions are arranged at a predetermined interval in the width direction Y. In the case, the distance between the high basis weights 41 in the high basis weight rows adjacent to each other may also be staggered. In other words, the high basis weight portion 41 can also project the high basis weight portion 41 in the specific high basis weight row in the direction orthogonal to the high basis weight portion row (width direction Y), and the adjacent high base. The projection images of the heavy portion 41 are arranged in an inconsistent manner. In this way, the grooves 7 (the lateral grooves 7Y1 and 7Y2) extending in the width direction Y are not convexly curved outward in the longitudinal direction X of the sanitary napkin 1A as in the above-described embodiment (see FIG. 3). The shape of the horizontally long shape is formed (for example, even if the lateral grooves 7Y1, 7Y2 are formed in a linear shape extending in the width direction Y), the lateral grooves 7Y1, 7Y2 and the low basis weight portion 42 can be prevented from completely matching each other.

Further, as described above, the groove 7 is sandwiched between the two high basis weight portions 41 and 41 arranged in the longitudinal direction X or the width direction Y of the sanitary napkin 1A, and held by the two high basis weight portions 41 and 41. A method in which one of the low basis weight portions 42 is connected to each other, in other words, a method in which the groove 7 and the low basis weight portion 42 of the absorbent core 40A are not completely matched, except that the groove 7 is included in a plan view as in the above embodiment In addition to the method in which the shape of the flat portion of the sanitary napkin 1A is convex and curved, and the low basis weight portion 42 is formed in a straight line shape in a plan view, the following method may be used: a) a high base having a relatively large size. A low basis weight portion 42 having a relatively small size is disposed around the heavy portion 41; b) as the high basis weight portion 41 combined with the low basis weight portion 42, a high base having a polygonal shape in a plan view shape of a pentagon or more is used alone. One type of the heavy portions 41 or two or more types are used in combination; c) the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 are extended) and the direction in which the low basis weight portions are formed (the linear low basis weight portions) The angle formed by the extension direction is set to 30 to 60°.

Further, although one of the application examples of the absorbent article of the present invention (first invention) is a menstrual sanitary napkin, the present invention is also applicable to, for example, a disposable diaper, an incontinence pad, a sanitary pad, and the like.

Hereinafter, a menstrual sanitary napkin which is one preferred embodiment of the absorbent article according to the present invention (second invention) will be described with reference to the drawings. As shown in FIG. 12 and FIG. 13, the sanitary napkin 1B of the present embodiment includes a front sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and two sheets. 2, 3 of the absorber 4B, and is longitudinal (long shape in one direction). As shown in Fig. 12, the sanitary napkin 1B includes, in the longitudinal direction X, the excretory portion opposing portion 11 that is disposed opposite to the wearer's excretory portion (vaginal opening) when worn, and is disposed in the excretory portion opposing portion 11 when worn. Further, the front side portion 12 of the wearer's ventral side and the rear side portion 13 of the wearer are disposed closer to the excretory portion opposing portion 11 when worn. The excretory portion opposing portion 11 is a portion having a pair of side flap portions 6 and 6 on the right and left sides. The pair of side flap portions 6 and 6 are used to refasten the sanitary napkin 1B to the underarm portion (the crotch portion) when the sanitary napkin 1B is fixed to an undergarment or the like. In the case where the absorbent article (menstrual sanitary napkin) of the present invention (the second invention) does not have the side flap portion, the length of the opposing portion of the menstrual sanitary napkin excretion portion in the longitudinal direction of the product is 25 cm or less. In the short-term daily sanitary napkin, the center portion (the second region from the front to the back) in the case where the sanitary napkin is divided into three equal parts in the longitudinal direction is the front portion, the center portion, and the rear portion. The total length of the direction is more than 25 cm In the long-term daily and night sanitary napkins, the second region (the third region from the back to the front) from the front to the back in the case where the sanitary napkins are equally divided into four in the longitudinal direction.

Further, in the present specification, the skin contact surface is the surface of the absorbent article or the constituent member facing the wearer's skin side when the absorbent article is worn, and the non-skin contact surface is an absorbent article or a member thereof. When facing the absorbent article, it faces the side opposite to the skin side (cloth side). Further, the longitudinal direction is along the longitudinal direction of the absorbent article or its constituent members, and the width direction is a direction orthogonal to the longitudinal direction. In the figure, the direction indicated by the symbol X is the longitudinal direction of the absorbent article (absorbent body or absorbent core), and the direction indicated by the symbol Y is the width direction of the absorbent article (absorbent body or absorbent core).

As shown in FIG. 13 , the front sheet 2 covers the entire area of the skin contact surface 4 a of the absorber 4B, and further extends from the left and right edges of the absorber 4B in the longitudinal direction X to the outside of the width direction Y. The back sheet 3 covers the entire area of the non-skin contact surface 4b of the absorber 4B, and further extends from the both side edges of the absorber 4B to the outside in the width direction Y. Further, the front sheet 2 and the back sheet 3 are also extended from the front end and the rear end of the longitudinal direction X of the absorber 4B to the outside of the longitudinal direction X, and by the adhesive, heat in the extensions Bonding, ultrasonic sealing, and the like are known to be joined to each other by means of a known joining means.

As shown in FIGS. 12 and 13 , a pair of side sheets 5 and 5 are disposed over the entire length direction X of the sanitary napkin 1B on both sides of the sanitary napkin 1B in the longitudinal direction X. In the side sheet 5, the side portion on the inner side in the width direction Y is abutted against the skin 2a of the front sheet 2 by a known joining means. The joining, the side of the outer side extends from the side edge of the absorbent body 4B in the longitudinal direction X to the outside of the width direction Y, and the extending portion thereof is derived from the absorbent body in the back sheet 3 by a known joining means. The extension of the side edge of 4B is joined. The back sheet 3 and the side sheet 5 have the largest extension in the width direction Y from the side edge of the absorbent body 4B in the excretion portion opposing portion 11, and a pair of side flap portions 6 are formed by the maximum extension portions. 6, 6.

The non-skin contact surface of the sanitary napkin 1B (the non-skin contact surface 3b of the back sheet 3) is worn toward the garment side such as the crotch portion of the shorts. An adhesive portion (not shown) for fixing the sanitary napkin 1B to the crotch portion of the underwear such as a pair of shorts is provided on the non-skin contact surface 3b. Further, an adhesive portion for fixing to the outer surface of the shorts (non-skin contact surface) is provided on the non-skin contact surface (the non-skin contact surface 3b of the back sheet 3) of the pair of side flap portions 6 and 6 ( Not shown). These adhesive portions are provided by applying a hot-melt adhesive to a specific portion, and are covered with a release sheet (not shown) including a film, a nonwoven fabric, a paper, or the like before the use of the sanitary napkin 1B.

The absorber 4B is configured to include an absorbent core 40B containing an absorbent material (a fibrous material such as pulp or a water-absorbent polymer). The absorber 4B in the present embodiment is configured by covering the absorbent core 40B with a core material (not shown) including a toilet paper or a water-permeable nonwoven fabric. The absorbent core 40B may include only the fibrous material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42 described below, or may be composed of the fibrous material and the water-absorbing polymer, and the latter In a case, it may be a form in which a water-absorbent polymer is uniformly mixed between the fiber materials, or may be a fiber layer mainly composed of a fiber material and a polymer layer mainly composed of a water-absorbing polymer, and may be The form of the polymer layer is sandwiched between the two layers of the fiber layers. The front sheet 2 and the absorber 4B and the absorber 4B and the back sheet 3 may be bonded to each other by an adhesive (hot melt adhesive or the like) applied by patterning such as dots, spirals, or stripes.

The absorber 4B includes a high basis weight portion 41 having a relatively high basis weight, and a low basis weight portion 42 adjacent to the high basis weight portion 41 and having a relatively low basis weight. In the present embodiment, as shown in Figs. 13 and 14, the absorbent core 40B constituting the absorbent body 4B has an absorbent material which is alternately formed in a specific direction (each of the longitudinal direction X and the width direction Y). The high basis weight portion 41 has a concave-convex structure formed by a low basis weight portion 42 (42X, 42Y) having a relatively small amount of absorbent material. As shown in Fig. 13, the outer diameter of the absorbent core 40B is uniform. More specifically, in the absorbent core 40B, as shown in FIG. 14, a plurality of low basis weight portions 42X extending in the longitudinal direction X (continuous linear shape) and extending in the width direction Y are formed. In the linear (continuously linear) low basis weight portion 42Y, the low basis weight portion 42 is formed in a lattice shape as a whole, and is divided by the linear low basis weight portions 42X and 42Y (the hole of the lattice) The position becomes a high basis weight 41. A plurality of linear low basis weight portions 42X are formed extending over the entire length X of the absorbent core 40B, and a plurality of linear low basis weight portions 42Y are respectively spread throughout the width direction of the absorbent core 40B. The full length extends to form. The plurality of high basis weight portions 41 have a rectangular shape in plan view as shown in Fig. 14(a).

The low basis weight portion 42 (42X, 42Y) is biased against the skin contact surface 4a side in the thickness direction T of the sanitary napkin 1B (absorbent core body 40B) as shown in Figs. 12 and 13 . Moreover, the low basis weight portion 42 is biased in the thickness direction in such a manner The skin of the T abuts against the surface 4a, and the high basis weight portion 41 protrudes toward the opposite side of the skin contact surface 4a, that is, the non-skin contact surface 4b side in the thickness direction T. Therefore, in the absorbent core 40B, the skin contact surface 4a (the surface facing the front sheet 2) is substantially flat except for the portion where the groove 7 is formed, and the other portions are substantially free from unevenness. The non-skin contact surface 4b (the surface facing the back sheet 3) has a high basis weight portion 41 (protrusion portion) formed by protrusion and a low basis weight portion 42 between the high basis weight portions 41, 41 (non-convex) Concavities and convexities formed by the portion or the recess.

In the absorbent core body 40B (the above-mentioned uneven structure) of the present embodiment, a plurality of absorbent portions including a rectangular shape in a plan view of the absorbent material are disposed apart from each other on one side of the absorbent material in which the outer shape is formed into a thin plate shape. In this respect, it may be similar to the absorbent body described in Patent Documents 2 and 3 (an absorbent body in which a plurality of absorbent portions are fixed to a sheet). However, the absorbent core 40B of the present embodiment differs from the absorbent bodies described in Patent Documents 2 and 3 in that the absorbent core 40B of the present embodiment is formed and absorbed in such a manner as to have the above-described uneven structure as described below. As a material manufacturer, the high basis weight portion 41 and the low basis weight portion 42 are integrated without bonding means such as an adhesive or heat fusion, and do not have the boundary of the same material (high basis weight portion 41 and low basis) In contrast, in the absorption system described in Patent Documents 2 and 3, the plurality of the absorption portions are fixed to the sheet which is different from the absorption portion, and the above-described sheet is produced. The absorbing portion and the sheet are joined to each other via a joining means, and have a boundary between the absorbing portion and the sheet. In addition, the high basis weight portion 41 and the low basis weight portion 42 of the present embodiment have continuity in which the liquid can smoothly move, and the patent documents 2 and 3 are described. In the above-mentioned absorbing portion and the above-mentioned sheet in the absorbent body, since the interface including the joining means exists between the two (border), the liquid in the boundary portion is likely to be diffused, and it is difficult to say that the liquid can be smoothly moved continuously. .

As shown in FIGS. 12 to 14, the sanitary napkin 1B has a groove 7 in which the front sheet 2 and the absorbent body 4B (absorbent core 40B) are integrally recessed. The groove 7 is a space defined by the bottom wall portion 71 and the side wall portion 72 (the portion where the sanitary napkin 1B does not have a material to be formed). As shown in Fig. 14 (a), the groove 7 includes a pair of left and right vertical grooves 7X and 7X extending continuously in the longitudinal direction X and two lateral grooves 7Y1 and 7Y2 extending continuously in the width direction Y. And the four grooves are connected at their respective ends to form an annular groove as a whole. The pair of longitudinal grooves 7X and 7X extend from the left and right sides of the absorbent core 40B in the longitudinal direction X over the entire length X of the discharge portion opposing portion 11 and further extend to the front portion 12 and Rear part 13. The lateral groove 7Y1 and the lateral groove 7Y2 are formed in the front portion 12 and the rear portion 13, respectively. Any one of the two lateral grooves 7Y1 and 7Y2 is formed in a shape of a horizontally long curved shape which is convex outward in the longitudinal direction X in plan view, and the top of each of the lateral grooves 7Y1 and 7Y2 is located in the width direction Y. Central.

As shown in Fig. 14, the grooves 7 (7X, 7Y1, 7Y2) include shallow groove portions 73 which are relatively shallowly recessed, and deep groove portions 74 which are recessed relatively deep. The groove 7 is alternately connected in the longitudinal direction of the groove 7 by the shallow groove portion 73 and the deep groove portion 74, and a continuous line is formed as a whole. When the groove 7 is formed by compressing the absorbent core 40B together with the front sheet 2 by embossing, the shallow groove portion 73 is subjected to relatively weak compression in the embossing process and the bottom depth (bottom) The wall portion 71 is shallower than the depth of the skin abutting surface 2a, and the deep groove portion 74 is attached to the embossing process. The part that is relatively strongly compressed and has a deeper bottom. The planar shape of the shallow groove portion 73 and the deep groove portion 74 is not particularly limited, and may be a rectangle, a square, a diamond, a circle, a cross or the like.

The grooves 7 (7X, 7Y1, 7Y2) can be formed by a usual method by embossing with heat or embossing without heat or ultrasonic embossing. That is, in the manufacturing step of the sanitary napkin 1B, after the front sheet 2 is supplied to one surface of the absorbent body 4B (absorbent core 40B having the uneven structure), the specific portion is applied from the front sheet by embossing. The 2 side is pressed (compressed) in a concave shape toward the absorber 4B side, whereby the groove 7 can be formed at the specific portion. In the groove 7, the front sheet 2 and the absorber 4B are integrated by heat fusion or the like.

The groove 7 is formed across a high basis weight portion (protrusion portion) 41 and a low basis weight portion (non-convex portion or recess portion) 42. More specifically, the groove 7 is a pair of high basis weights (protrusions) 41, 41 adjacent in a specific direction and a low basis weight held by the two high basis weights 41, 41 (non- Concavities or recesses 42 are formed in series. In the present embodiment, as shown in Fig. 14 (a), in the longitudinal direction X, the excretory portion opposing portion 11 which is a portion directly receiving the excretory liquid is regarded as one of the grooves 7 as a pair of the longitudinal grooves 7X and 7X, respectively. Formed by connecting two high basis weight portions 41, 41 adjacent in the longitudinal direction X and one low basis weight portion 42Y between the two, and having an absorbent core connected across the length direction X 40B is formed by the unevenness. Further, in the width direction Y, in the front portion 12, the lateral groove 7Y1 which is a portion of the groove 7 is lower than the two high basis weight portions 41, 41 which are adjacent in the width direction Y, and one between the two. The base portions 42X are formed in series, and further, in the rear portion 13, the lateral grooves 7Y2 which are a part of the grooves 7 are formed in the same manner.

The positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is more important in terms of the absorption and diffusion of the excretory liquid of the present invention (second invention), particularly as described above. In general, the groove 7 (longitudinal groove 7X) is formed in the longitudinal direction X across the high basis weight portion (protrusion portion) 41 and the low basis weight portion (non-convex portion or concave portion) 42 and from the drain liquid to the width direction Y. It is important to prevent the leakage of the excretory fluid caused by the movement to the outside (so-called side leakage). Therefore, in the present embodiment, the design of the arrangement in which the longitudinal grooves 7X are arranged to straddle the unevenness is used, and the "sanitary cotton 1B is included in the linear shape (continuous linear shape) extending in the longitudinal direction X thereof. The base portion 42X has a configuration in which the vertical groove 7X extending in the longitudinal direction X includes a portion having a length direction different from the linear low basis weight portion 42X. In other words, in the present embodiment, as described above, the low basis weight portion 42X is formed in a linear shape extending in the longitudinal direction X in plan view, and the vertical groove 7X is formed as shown in Fig. 14(a) in plan view. In each of the both side portions in the longitudinal direction X of the sanitary napkin 1B in the opposing portion 11 of the excretion portion, the longitudinal shape (curved portion) which is convexly curved outward in the width direction Y of the sanitary napkin 1B is included. The portion formed in a manner different from the linear low-basic portion 42X in the longitudinal direction is formed to include a curved line including the curved portion. In this manner, the low basis weight portion 42X of the absorbent core 40B is formed in a linear shape that completely coincides with the longitudinal direction X of the absorbent core 40B, and the longitudinal groove 7X is not completely aligned with the longitudinal direction X ( The curved portion is formed in a partially uniform manner, whereby at least the curved portion of the vertical groove 7X does not completely coincide with the linear low base portion 42X extending in the longitudinal direction X in plan view, so that the longitudinal groove 7X becomes It is easy to form in the longitudinal direction X across the high basis weight portion 41 and the low basis weight portion 42. to make.

The cross section of the groove 7 in each portion of the absorbent core 40B is schematically shown in Figs. 15 to 17 . As shown in FIGS. 15 to 17, the grooves 7 (7X, 7Y1, and 7Y2) are defined by the bottom wall portion 71 and the side wall portion 72 that is erected from the bottom wall portion 71. In addition, in FIGS. 15 to 17, the illustration of the shallow groove portion 73 and the deep groove portion 74 is omitted, and the bottom wall portion 71 is described as having no step in the longitudinal direction of the groove 7. The difference is substantially flat, but actually the position of the bottom wall portion of the shallow groove portion 73 and the deep groove portion 74 in the thickness direction of the absorbent core is different, and the bottom wall portion 71 of the shallow groove portion 73 is away from the front sheet 2 Relatively close, the bottom wall portion 71 of the deep groove portion 74 is relatively far from the front sheet 2, and therefore, the actual bottom wall portion 71 is formed with a shallow groove portion 73 located at a relatively high position and relatively located. The deep groove portion 74 at the lower position corresponds to the step difference.

In the present embodiment, the high basis weight portion 41 has a lower density than the base portion 42 and has a density gradient in the high basis weight portion 41, the low basis weight portion 42, and the groove 7 and its vicinity. That is, in Fig. 14 (b) and Figs. 15 to 17, the density of the portion indicated by the symbols A to E is A ≦ B < < C < < E, and more preferably A < B < < C < D < E The farther the groove 7 (the longitudinal groove 7X) is, the lower the density (the portion A), and the closer the groove 7 is, the higher the density (the portion B and/or C) is in the groove 7 (the bottom wall portion 71). The density is maximized (parts D and E). Further, with respect to the groove 7 (the bottom wall portion 71), the density of the portion D in the low basis weight portion 42 (42Y) is slightly lower than the portion E in the high basis weight portion 41, thereby increasing the diffusibility of the liquid along the groove 7 ( It is more preferable that the density of the portion D is higher than the position of the groove 7 in the base portion 41, that is, the portion C is high. The closer to the groove 7, the density density becomes higher, which is mainly caused by the groove 7 formed by the embossing process (compression of the absorbent core 40B), and also exists first. The former is formed in an absorber having a leakage preventing groove. Regarding the density gradient, in the present embodiment, the characteristic aspect is B<<C, that is, the density of the high basis weight portion 41 is higher in the entire absorbent core 40B than in the base portion 42, and the relationship is higher than the groove 7. It is also established nearby. The term "near the groove" means the side wall portion 72 (see Figs. 15 to 17) of the groove 7 and its vicinity, and mainly refers to the groove 7 (the outer surface of the side wall portion 72) to the length of the groove 7. A portion within 5 mm of the direction orthogonal to the direction (the width direction of the groove 7).

Thus, the vicinity of the groove 7 (longitudinal groove 7X), that is, the portions B and C are the same distance from the groove 7, but the density of the portion C located at the high basis weight portion 41 is higher than the portion B located at the low basis weight portion 42 (42Y). The reason is that since the high basis weight portion 41 has more absorbent material in the lower basis weight portion 42 before the groove 7 is formed by compressing the absorbent core 40B, the density is higher. In other words, the absorbent core 40B of the present embodiment is obtained by depositing an absorbent material so as to include the high basis weight portion 41 and the low basis weight portion 42 as described below, thereby obtaining a deposit having a concavo-convex structure. When the pressure roller or the like compresses the entire deposit by a uniform compressive force, the high basis weight portion 41 as a convex portion is more compressed than the low basis weight portion 42 which is a non-convex portion or a concave portion in the above-described compression step. Therefore, the density of the high basis weight portion 41 (the portion C) is lower than that of the base portion 42 (the portion B). Thus, there is a difference in density before the formation of the groove 7 in the portion B and the portion C, and if the groove 7 is formed by compressing the portion B and the portion C, the density is reflected in the side wall portion 72 of the dividing groove 7 and its vicinity. The result is that B<<C with respect to density.

Further, in the low basis weight portion 42 of the present embodiment, as shown in Fig. 15, the basis weight of the side wall portion 72 (the portion B, "the vicinity of the groove") of the groove 7 (longitudinal groove 7X) is lower than that of the lower portion. The side wall portion 72 is spaced apart from the groove 7 (longitudinal groove 7X) Bit A (where the "near the slot" is further apart from the slot). The difference in basis weight caused by the distance from the groove 7 in such a low basis weight portion 42 is caused by the groove 7 formed by the embossing process (compression of the absorbent core 40B). In other words, in the process of forming the groove 7 by the embossing, the portion (the portion D) which becomes the bottom wall portion 71 of the final dividing groove 7 is pressed in a concave shape as the press-in center in the low basis weight portion 42. By the press-fitting of the low basis weight portion 42, the vicinity of the press-in center (portion B) is selectively extended to lower the basis weight, and the portion farther from the press-in center (part A) It does not extend substantially (the basis weight does not change), and as a result, the vicinity of the press-in center (part B) becomes the side wall portion 72 whose basis weight is lower than the portion A. As described above, if the basis weight of the side wall portion 72 defining the groove 7 in the low basis weight portion 42 is lower than the portion farther apart from the groove 7, the amount of the discharge liquid by the side wall portion 72 is lowered, and therefore, as follows As described above, it is effective to prevent the excretion liquid from moving beyond the groove 7 and moving to the outside of the width direction Y of the sanitary napkin 1B. From the viewpoint of more reliably exerting the above-described effects in the low basis weight portion 42, the side wall portion 72 in the low basis weight portion 42 [near the groove 7 (in the width direction of the groove 7 away from the side wall portion 72) The basis weight of the portion within 5 mm of the outer surface is set to W1, and the portion of the low basis weight portion 42 located farther from the groove 7 than the side wall portion 72 (in the width direction of the groove 7 from the side wall) When the basis weight of the portion where the outer surface of the portion 72 is separated by 5 mm or more is W2, the ratio of the two basis weights (W1/W2) is preferably 1.1 to 15, more preferably 1.2 to 3.0.

The sanitary napkin 1B of the present embodiment has the absorbent body 4B (absorbent core 40B) including the high basis weight portion 41 and the low basis weight portion 42 adjacent to the high basis weight portion 41 such that the groove 7 spans the high base. The heavy portion 41 and the low basis weight portion 42 are formed to exert the absorption and diffusion effects of the excretory liquid described below, thereby The amount of excretion such as blood can be quickly absorbed and spread. When the absorption and diffusion action of the excretion liquid in the sanitary napkin 1B of the present embodiment is described with reference to Fig. 14 (b), the excretion fluid W such as menstrual blood excreted by the wearer of the sanitary napkin 1B is usually the excretion portion opposing portion 11 The central portion of the width direction Y is caught, and moves from the skin abutting surface (the skin abutting surface 2a of the front sheet 2) toward the groove 7 (longitudinal groove 7X) in the width direction Y, for example, in FIG. 14(b) In the case where the portion A (near the center portion in the width direction Y of the excretion portion opposing portion 11) faces the portion B (near the groove 7 in the low basis weight portion 42), the constituent members of the sanitary napkin 1B are formed (front side). The sheet 2, the absorbent core 40B, and the like) are moved. As described above, since there is a difference in density between the portion B and the portion C and the density is B < C, the excretion liquid W reaching the portion B is easily moved to the vicinity of the groove 7 in the high basis weight portion 41 by the capillary force, that is, the portion C. It is not easy to stay in the part B. In this manner, the excretory fluid W moves in the vicinity of the groove 7 and in the width direction Y of the groove 7, and moves along the groove 7 in the front-rear direction of the sanitary napkin 1B, so that the opposite portion 11 from the excretory portion is promptly elongated in the longitudinal direction X. Diffusion.

Since the portion B is not only a gap (space) between the adjacent high basis weight portions 41, 41, but also exists as a part of the absorbent core 40B (low basis weight portion 42), it has a function of retaining the excretion liquid. Therefore, even when the amount of the excretory fluid W is large and the movement speed of the excretory fluid W from the portion A to the portion B is faster than the movement speed of the excretory fluid W from the portion B to the portion C (the diffusion speed in the longitudinal direction X) Further, the excretion liquid can be temporarily held at the portion B, and therefore, a large amount of the excretion liquid is prevented from simultaneously moving to the portion D (the low basis weight portion 42 which is located outside the width direction Y of the sanitary napkin 1B at the portion B). The bottom wall portion 71) of the groove 7 is divided, and further, the excretion liquid W is prevented from moving over the groove 7 to the sanitary napkin 1B. The lateral direction of the width direction Y causes side leakage. Further, as described above, the basis weight of the portion B is lower than that of the portion A, and when the delivery amount of the excretion liquid is lowered by the low basis weight thereof, the decrease in the discharge capacity of the excretion liquid at the portion B also suppresses the liquid from the portion B to the portion. The movement of D helps to prevent side leakage.

The excretion liquid W is rapidly absorbed and held by the high basis weight portion 41 in the vicinity of the groove 7 and moved in the width direction Y from the groove 7 to the portion C, exceeding the high basis weight portion 41. The portion of the absorption capacity is moved to a portion E (the bottom wall portion 71 of the dividing groove 7 in the high basis weight portion 41) which is located outside the width direction Y in the portion C as shown in Fig. 17 . The portion E is a portion that is most compressed when the groove 7 is formed (at the time of compression), and since the density is much higher than the portion C adjacent in the width direction Y, the excretion liquid W is difficult to move from the portion E to the portion C. It is difficult to cause the excretion liquid W to move beyond the groove 7 and move to the outside of the width direction Y of the sanitary napkin 1B. This is the same as the relationship between the portion B and the portion D in the low basis weight portion 42 described above. The excretion liquid W that has moved to the portion E via the portion C does not leak to the outer side of the groove 7, but moves to the adjacent portion D (the bottom wall portion 71 of the dividing groove 7 in the low basis weight portion 42) through the groove 7, and further , move to another part E adjacent to it. Thus, the excretory fluid W moving in the tank 7 is mainly absorbed and held by the high basis weight portion 41 during its movement.

As described above, in the sanitary napkin 1B of the present embodiment, the excretion liquid discharged to the central portion in the width direction Y of the excretion portion opposing portion 11 is in the vertical groove 7X and in the vicinity of the vertical groove 7X and is wider than the vertical groove 7X. Both of the portions in the direction Y are rapidly diffused in the front and rear directions of the sanitary napkin 1B, and are rapidly absorbed and held mainly by the high basis weight portion 41 in the middle of the above diffusion. Therefore, this is The sanitary napkin 1B can rapidly diffuse and absorb the excreted excretion by utilizing the diffusion and absorption of the excretion fluid combined with the absorption body 4B (absorbent core 40B) and the groove 7. It is thus difficult to generate side leakage, and the wearer's discomfort caused by wetting can be eliminated.

Further, in the sanitary napkin 1B of the present embodiment, the configuration of the groove 7 is designed to improve the flexibility by the diffusion and absorption of the excretion liquid combined with the absorbent body 4B and the groove 7. This improves the fit of the sanitary napkin 1B to the wearer's body. The configuration of the groove 7 is such that the shallow groove portion 73 and the deep groove portion 74 have a longer length in the longitudinal direction of the groove. That is, as an example of the vertical groove 7X extending in the longitudinal direction X, as shown in Fig. 18(a), the length L8 of the longitudinal direction X of the vertical groove 7X of the shallow groove portion 73 is longer than the length of the deep groove portion 74. The length of the direction X is L9 long. The length relationship between the shallow groove portion 73 and the deep groove portion 74 is also the same for the lateral groove 7Y.

As described above, the shallow groove portion 73 is subjected to a relatively weak compression low density portion in the embossing process when the groove 7 is formed, and the deep groove portion 74 is relatively strongly compressed in the embossing process. In the density portion, if the length L9 of the high-density deep groove portion 74 is longer than the length L8 of the lower density shallow groove portion 73, and the proportion of the deep groove portion 74 in the groove 7 is increased (that is, the shallow groove portion 73 is occupied). In addition to the influence of the groove forming direction on the groove 7, the groove 7 is hardened as a whole, so that the softness of the sanitary napkin 1B is lowered and the sanitary napkin 1B is difficult. The fit is reduced by the fit of the wearer's body. On the other hand, the deep groove portion 74 is a portion in which the structure of the groove 7 is stabilized and the excretion liquid is prevented from moving beyond the groove 7 and moving to the outside of the width direction Y of the sanitary napkin 1B (side leakage). 7 of the deep groove part 74 When the ratio is decreased (i.e., the proportion of the shallow groove portion 73 is increased), the side leakage prevention property of the groove 7 is lowered.

Fig. 18 (b) and Fig. 18 (c) show the self-contradictory relationship between the flexibility (suitability) in such a groove and the prevention of side leakage. As shown in FIGS. 18(b) and 18(c), the absorptive core 40B' which does not include the high basis weight portion and the low basis weight portion and has a uniform basis weight includes a shallow groove portion 73 and a deep groove portion. In the case of the groove 7 (the vertical groove 7X) of 74, as shown in Fig. 18 (b), the length of the groove in the longitudinal direction X is equal to the shallow groove portion 73 and the deep groove portion 74 (set to L8 = L9) In addition, the longitudinal groove 7X is hard and is disadvantageous in terms of flexibility (suitability), and on the other hand, it plays an advantageous role in the side leakage prevention property, so that it is difficult for the excretion liquid W to exceed the longitudinal groove 7X and the width direction Y. The square moves, and it is easy to move along the longitudinal groove 7X within the width direction Y of the longitudinal groove 7X. Further, as shown in Fig. 18(c), when L8 > L9, the ratio of the shallow groove portion 73 having a low density to the vertical groove 7X increases, and the flexibility of the vertical groove 7X (suitability) The shape shown in FIG. 18(b) is improved, but it is disadvantageous for the side leakage prevention property. Therefore, as shown by the symbol W1 in FIG. 18(c), the excretion liquid exceeds the longitudinal groove 7X. The movement to the outside of the width direction Y of the sanitary napkin 1B increases.

On the other hand, in the present embodiment, as the absorber (absorbent core) forming the groove 7, the absorber 4B (absorbent core 40B) is used as described above, and the absorber 4B (absorbent core 40B) The high basis weight portion 41 and the low basis weight portion 42 adjacent thereto are provided, and regardless of the relationship between the length of the shallow groove portion 73 and the deep groove portion 74, the drainage liquid exhibits excellent diffusion and absorption effects, and further has Since the liquid mobility is derived from the structure around the groove 7, the above-mentioned size can be determined from the viewpoint of improving the flexibility (suitability) of the groove 7. Therefore, the configuration in which the shallow groove portion 73 is longer than the deep groove portion 74 in the longitudinal direction of the groove can be employed, thereby improving the flexibility (suitability) of the sanitary napkin 1B. The ratio L8/L9 of the length L8 (see FIG. 18(a)) in the longitudinal direction of the groove of the shallow groove portion 73 and the length L9 (see FIG. 18(a)) of the deep groove portion 74 in the longitudinal direction is preferably 1.2~18, better 1.2~4.0. Further, the length L8 of the groove in the shallow groove portion 73 in the longitudinal direction is preferably 1.2 to 18.0 mm, more preferably 1.2 to 4.0 mm.

From the viewpoint of more effectively exerting the effect of the above-described sanitary napkin 1B, it is preferable to set the size and the like of each portion as follows.

The ratio (S41/S42) of the basis weight S41 of the high basis weight portion 41 of the absorbent core 40B to the basis weight S42 of the low basis weight portion 42 is preferably 1.25 or more, more preferably 3 or more, and more preferably 10 Hereinafter, it is more preferably 6 or less.

The basis weight S41 of the high basis weight portion 41 is preferably 100 g/m ² or more, more preferably 150 g/m ² or more, and further preferably 600 g/m ² or less, more preferably 500 g/m ² or less. The basis weight S42 of the low basis weight portion 42 is preferably 10 g/m ² or more, more preferably 30 g/m ² or more, and further preferably 150 g/m ² or less, more preferably 100 g/m ^{2 .} the following.

The ratio (T41/T42) of the thickness T41 of the high basis weight portion 41 to the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and is preferably 20 or less, more preferably 10 or less.

The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and further preferably 10 mm or less, more preferably 8 mm or less, and the thickness T42 of the low basis weight portion 42 is preferably 0.1. More than mm, more preferably 0.2 mm or more, and further preferably 5.0 mm or less, more preferably 3.0 mm or less.

The width L1 (see Fig. 14 (a)) of the low basis weight portion 42 is preferably 1 mm or more, and is preferably 5 mm or less, more preferably 3 mm or less. In the low basis weight portions 42X and 42Y, the width L1 may be the same or different.

The size of the high basis weight portion 41 as shown in Fig. 14(a) is different depending on the type and use of the absorbent article, and the length L2 in the longitudinal direction X in the sanitary napkin such as the sanitary napkin 1B (refer to Fig. 14 (a)) is preferably 5 mm or more, more preferably 10 mm or more, and more preferably 50 mm or less, more preferably 30 mm or less, and a length L3 in the width direction Y (refer to Fig. 14 (a)) It is preferably 3 mm or more, more preferably 5 mm or more, and more preferably 30 mm or less, more preferably 20 mm or less.

Preferably, the area of the high basis weight portion 41 is preferably 5 or more, more preferably 10 or more, per 50 cm ² , and more preferably 70 or less, more preferably 60 or less.

The width L5 (see Fig. 14 (b)) of the grooves 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and is preferably 5.0 mm or less, more preferably 4.0 mm or less.

The depth L6 (refer to Fig. 16) of the groove 7 is preferably 0.5 mm or more, more preferably 1.0 mm. Further, the depth L6 means the depth of the deep groove portion 74 which is the deepest portion of the groove 7. The depth of the shallow groove portion 73 is preferably less than 0.5 mm, more preferably less than 1.0 mm.

Further, the size of each portion of the groove 7 may be measured by using a ruler or the like, but it is preferably measured using a digital microscope. For example, the groove 7 can be enlarged and photographed using a digital microscope VHX-1000 manufactured by KEYENCE, and the size of each portion can be measured. The width L5 of the above groove 7 is tied to the groove 7 The bottom surface is measured and obtained. Further, the depth L6 of the groove 7 is obtained by measuring the cross section of the groove 7 by a digital microscope.

The shallow groove portion 73 is preferably such that the length X of the sanitary napkin 1B is shorter than the base portion 41. For example, the longitudinal groove 7X extending in the longitudinal direction X is preferably such that the length L8 of the shallow groove portion 73 (see FIG. 18(a)) is shorter than the length L2 of the longitudinal direction X of the base portion 41 ( Refer to Figure 14(a)). According to the above configuration, the deep groove portion 74 in the vertical groove 7X is necessarily formed in the high basis weight portion 41, whereby the groove structure is stably formed, and the liquid retention performance is exhibited. The ratio (L8/L2) of the length L8 of the shallow groove portion 73 to the length L2 of the longitudinal direction X of the high basis weight portion 41 is preferably 0.06 to 0.9, more preferably 0.06 to 0.2.

Further, in the present embodiment, the portion of the non-skin contact surface 4b of the absorbent core 40B (absorbent body 4B) corresponding to the groove 7 (the portion where the bottom wall portion 71 of the groove 7 is formed) is preferably The lower basis weight portion 42 has a higher base weight portion 41 closer to the front sheet 2 (farther from the back sheet 3). That is, if the longitudinal groove 7X extending in the longitudinal direction X is taken as an example, as shown in Fig. 17, the portion of the low basis weight portion 42 corresponding to the longitudinal groove 7X (the bottom wall defining the longitudinal groove 7X) is formed. The distance between the non-skin contact surface of the portion 71 of the portion 71 and the back sheet 3 is L42, and the distance between the non-skin contact surface of the high basis weight portion 41 and the back sheet 3 is set to L41. In the case, it is preferable that L42>L41. According to the above configuration, when the groove 7 is formed by embossing (when the absorbent core 40B is compressed), the problem that the low basis weight portion 42 is pressed and broken is avoided, and the groove 7 is formed more stably. If L42=L41 or L42<L41, the side wall portion 72 of the partition groove 7 in the low basis weight portion 42 has a flaw in the vicinity of the side wall portion 72. The difference between the separation distance L42 in the low basis weight portion 42 and the separation distance L41 in the high basis weight portion 41 (L42-L41) It is preferably 1.5 mm or less, more preferably 1.0 mm or less. Usually, the separation distance L41 is 0.5 mm or less.

When the materials for forming the respective portions of the sanitary napkin 1B are described, the front sheet 2 and the back sheet 3 can be used without any particular limitation, and various materials previously used in the technical field can be used. As the front sheet 2, for example, a liquid permeable sheet such as a non-woven fabric or an apertured film can be used. As the back surface sheet 3, for example, a resin film which does not have moisture permeability, a resin film which has fine pores and has moisture permeability, a nonwoven fabric such as water-repellent nonwoven fabric, a laminate of these and other sheets, or the like can be used. Further, as the side sheet 5, various materials previously used in the technical field can be used without particular limitation, and for example, a water-repellent non-woven fabric or a resin film-made sheet can be used.

As the absorbent material which is a material for forming the absorbent core 40B, various materials previously used in the art can be used without particular limitation. For example, as a fibrous material, natural fibers such as wood pulp, cotton, and hemp can be used; a composite fiber of a synthetic resin such as polyethylene or polypropylene; a semisynthetic fiber such as acetate or hydrazine. Further, as the absorbent material, in addition to the fibrous materials, various shapes of water-absorbent polymers such as pellets may be used.

The absorbent body (absorbent core) of the second aspect of the invention can be produced by the same method as the method for producing the absorbent body (absorbent core) of the first invention. The absorbent body 4B (absorbent core 40B) of the second invention can be produced in the same manner as the absorbent body 4A (absorbent core 40A) of the first invention, using the apparatus for producing an absorbent body shown in Fig. 7 . In the method for producing the absorbent body 4B (absorbent core 40B) according to the second aspect of the invention, a description will be given of a method for producing the absorbent body 4A (absorbent core 40A) according to the first aspect of the invention.

The present invention (second invention) is not limited to the above embodiment. For example, in the absorbent core 40B, the high basis weight portion 41 may be arranged in a zigzag shape. In other words, a plurality of high basis weight portions 41 are arranged at a predetermined interval in the longitudinal direction X to form a high basis weight portion row, and a plurality of the high basis weight portions are arranged at a predetermined interval in the width direction Y. In the case, the distance between the high basis weights 41 in the high basis weight rows adjacent to each other may also be staggered. In other words, the high basis weight portion 41 can also project the high basis weight portion 41 in the specific high basis weight row in the direction orthogonal to the high basis weight portion row (width direction Y), and the adjacent high base. The projection images of the heavy portion 41 are arranged in an inconsistent manner. If the grooves 7 (the lateral grooves 7Y1 and 7Y2) extending in the width direction Y are not as long as the above-described embodiment (see FIG. 14), they are convexly curved outward in the longitudinal direction X of the sanitary napkin 1B in a plan view. The shape is formed (for example, even if the lateral grooves 7Y1, 7Y2 are formed in a linear shape extending in the width direction Y), the lateral grooves 7Y1, 7Y2 and the low basis weight portion 42 can be prevented from completely matching each other.

Further, as described above, the groove 7 is sandwiched between the two high basis weight portions 41 and 41 arranged in the longitudinal direction X or the width direction Y of the sanitary napkin 1B, and held by the two high basis weight portions 41 and 41. A method in which one of the low basis weight portions 42 is connected to each other, in other words, a method in which the groove 7 and the low basis weight portion 42 of the absorbent core 40B are not completely matched, except that the groove 7 is included in a plan view as in the above embodiment In addition to the method of forming a curved shape toward the outside of the sanitary napkin 1B and forming the low basis weight portion 42 in a straight line shape in plan view, the following methods may be used: a) a relatively large-sized base A low basis weight portion 42 having a relatively small size is disposed around the heavy portion 41; b) as the high basis weight portion 41 combined with the low basis weight portion 42, a high base having a polygonal shape in a plan view shape of a pentagon or more is used alone. One type of the heavy portions 41 or two or more types are used in combination; c) the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 are extended) and the direction in which the low basis weight portions are formed (the linear low basis weight portions) The angle formed by the extension direction is set to 30 to 60°.

Moreover, although one of the application examples of the absorbent article of the present invention (second invention) is a menstrual sanitary napkin, the present invention is also applicable to, for example, a disposable diaper, an incontinence pad, a sanitary pad, and the like.

Hereinafter, a preferred sanitary napkin according to an embodiment of the absorbent article of the present invention (third invention) will be described with reference to the drawings. As shown in FIG. 19 and FIG. 20, the sanitary napkin 1C of the present embodiment includes a front sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and two sheets. 2, 3 between the absorber 4C, and is longitudinal (long shape in one direction). As shown in Fig. 19, the sanitary napkin 1C includes, in the longitudinal direction X, the excretory portion opposing portion 11 which is disposed opposite to the wearer's excretory portion (vaginal opening) when worn, and is disposed in the excretory portion opposing portion 11 when worn. Further, the front side portion 12 of the wearer's ventral side and the rear side portion 13 of the wearer are disposed closer to the excretory portion opposing portion 11 when worn. The excretory portion opposing portion 11 is a portion having a pair of side flap portions 6 and 6 on the right and left sides. The pair of side flap portions 6 and 6 are used to refasten the sanitary napkin 1C to the lower crotch portion (the crotch portion) of the undergarment when the sanitary napkin 1C is fixed to an undergarment or the like. Further, in the case where the absorbent article (menstrual sanitary napkin) of the present invention does not have a side flap portion, the so-called short-term daily use of the opposite portion of the menstrual sanitary napkin excretion portion in the longitudinal direction of the product is 25 cm or less. In the sanitary napkin, the center portion (the second region from the front to the rear) in the case where the sanitary napkin is divided into three in the longitudinal direction and is set to the front portion, the central portion, and the rear portion, and the length of the product is more than 25 cm in the longitudinal direction. The so-called long In the daily-use and night-use sanitary napkins, the second region (the third region from the back to the front) from the front to the back in the case where the sanitary napkins are equally divided into four in the longitudinal direction.

Further, in the present specification, the skin contact surface is the surface of the absorbent article or the constituent member facing the wearer's skin side when the absorbent article is worn, and the non-skin contact surface is an absorbent article or a member thereof. When facing the absorbent article, it faces the side opposite to the skin side (cloth side). Further, the longitudinal direction is along the longitudinal direction of the absorbent article or its constituent members, and the width direction is a direction orthogonal to the longitudinal direction. In the figure, the direction indicated by the symbol X is the longitudinal direction of the absorbent article (absorbent body or absorbent core), and the direction indicated by the symbol Y is the width direction of the absorbent article (absorbent body or absorbent core).

As shown in Fig. 20, the front sheet 2 covers the entire area of the skin contact surface 4a of the absorbent body 4C, and further extends from the left and right edges of the absorbent body 4C in the longitudinal direction X to the outside of the width direction Y. The back sheet 3 covers the entire area of the non-skin contact surface 4b of the absorber 4C, and further extends from the both side edges of the absorber 4C to the outside in the width direction Y. Further, the front sheet 2 and the back sheet 3 are also extended from the front end and the rear end of the longitudinal direction X of the absorber 4C to the outside of the longitudinal direction X, and by the adhesive, heat in the extensions Bonding, ultrasonic sealing, and the like are known to be joined to each other by means of a known joining means.

As shown in FIGS. 19 and 20, a pair of side sheets 5 and 5 are disposed over the entire length direction X of the sanitary napkin 1C in the left and right sides of the sanitary napkin 1C. In the side sheet 5, the side portion on the inner side in the width direction Y is abutted against the skin 2a of the front sheet 2 by a known joining means. The joining, the side of the outer side extends from the side edge of the absorbent body 4C in the longitudinal direction X to the outside of the width direction Y, and the extending portion thereof is derived from the absorbent body in the back sheet 3 by a known joining means. The extension of the side edge of 4C is joined. The back sheet 3 and the side sheet 5 have the largest extension in the width direction Y from the side edge of the absorbent body 4C in the excretion portion opposing portion 11, and a pair of side flap portions 6 are formed by the maximum extension portions. 6, 6.

The non-skin contact surface of the sanitary napkin 1C (the non-skin contact surface 3b of the back sheet 3) is worn toward the garment side such as the crotch portion of the shorts. An adhesive portion (not shown) for fixing the sanitary napkin 1C to the crotch portion of the underwear such as a pair of shorts is provided on the non-skin contact surface 3b. Further, an adhesive portion for fixing to the outer surface of the shorts (non-skin contact surface) is provided on the non-skin contact surface (the non-skin contact surface 3b of the back sheet 3) of the pair of side flap portions 6 and 6 ( Not shown). These adhesive portions are provided by applying a hot-melt adhesive to a specific portion, and are covered with a release sheet (not shown) including a film, a nonwoven fabric, a paper, or the like before the use of the sanitary napkin 1C.

The absorber 4C is configured to include an absorbent core 40C containing an absorbent material (a fibrous material such as pulp or a water-absorbent polymer). The absorber 4C in the present embodiment is configured by covering the absorbent core 40C with a core material (not shown) including a toilet paper or a water-permeable nonwoven fabric. The absorbent core 40C may include only the fibrous material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42 described below, or may be composed of the fibrous material and the water-absorbing polymer, and the latter In a case, it may be a form in which a water-absorbent polymer is uniformly mixed between the fiber materials, or may be a fiber layer mainly composed of a fiber material and a polymer layer mainly composed of a water-absorbing polymer, and may be The form of the polymer layer is sandwiched between the two layers of the fiber layers. Between the front sheet 2 and the absorber 4C, the absorber 4C and the back sheet 3 may be bonded to each other by an adhesive (hot melt adhesive or the like) applied by patterning such as dots, spirals, or stripes.

As shown in FIGS. 20 and 21, the absorbent core 40C includes a relatively high basis weight portion 41 having a relatively large amount of absorbent material, and a low basis weight portion 42 (42X, 42Y) having a relatively small amount of absorbent material, and a high base. The heavy portion 41 and the low basis weight portion 42 are alternately formed in a specific direction (each of the longitudinal direction X and the width direction Y). More specifically, in the absorbent core 40C, as shown in FIG. 21, a plurality of linear low base portions 42X extending in the longitudinal direction X and linear low bases extending in the width direction Y are respectively formed. In the heavy portion 42Y, the low basis weight portion 42 is formed in a lattice shape as a whole, and the portion partitioned by the linear low basis weight portions 42X and 42Y becomes the high basis weight portion 41. A plurality of linear low basis weight portions 42X are formed extending over the entire length X of the absorbent core 40C, and a plurality of linear low basis weight portions 42Y are respectively spread over the width direction of the absorbent core 40C. The full length extends to form. Each of the plurality of high basis weight portions 41 has a rectangular shape in plan view as shown in Fig. 21 (a).

Further, in the present embodiment, as shown in Fig. 20, since the thickness of the outer shape of the absorbent core 40C is uniformly formed, the thickness of the high basis weight portion 41 is small, and the basis weight portion 42 (42X, 42Y) is large. The absorptive core 40C has a concavo-convex structure in which the high basis weight portion 41 is raised by the lower basis weight portion 42. When the absorbent core 40C has a concavo-convex structure, it is easier to induce an absorbent core when wearing the sanitary napkin 1C than when the skin contact surface and the non-skin contact surface are not flat. The deformation of the body 40C (absorbent body 4C).

When viewed in the cross section of the absorbent core 40C shown in Fig. 20, the low basis weight portions 42 (42X, 42Y) are biased to one side in the thickness direction of the absorbent core 40C. More specifically, as shown in FIG. 20, the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction T of the absorbent core 40C. Further, since the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction T, the high basis weight portion 41 protrudes toward the opposite side of the skin contact surface 4a, that is, in the thickness direction T. The non-skin abutting surface 4b protrudes. Therefore, in the absorbent core 40C, the skin contact surface 4a (the surface facing the front sheet 2) is substantially flat except for the portion where the groove 7 is formed, and the other portions are substantially free from unevenness. The non-skin contact surface 4b (the surface facing the back sheet 3) has a high basis weight portion 41 (protrusion portion) formed by protrusion and a low basis weight portion 42 between the high basis weight portions 41, 41 (non-convex) Concavities and convexities formed by the portion or the recess.

In the absorbent core 40C (the above-mentioned uneven structure) of the present embodiment, a plurality of absorbent portions including a rectangular shape in a plan view of the absorbent material are disposed apart from each other on one side of the absorbent material in which the outer shape is formed into a thin plate shape. In this respect, it may be similar to the absorbent body described in Patent Documents 2 and 3 (an absorbent body in which a plurality of absorbent portions are fixed to a sheet). However, the absorbent core 40C of the present embodiment differs from the absorbent bodies described in Patent Documents 2 and 3 in that the absorbent core 40C of the present embodiment is formed and absorbed in such a manner as to have the above-described uneven structure as described below. As a material manufacturer, the high basis weight portion 41 and the low basis weight portion 42 are integrated without bonding means such as an adhesive or heat fusion, and do not have the boundary of the same material (high basis weight portion 41 and low basis) In contrast, the absorption systems described in Patent Documents 2 and 3 have a plurality of the above-described absorption portions. The sheet is fixed to the sheet which is different from the absorbent portion, and the absorbent portion and the sheet are joined to each other via a joining means, and have a boundary between the absorbent portion and the sheet. In addition, the high basis weight portion 41 and the low basis weight portion 42 of the present embodiment have continuity in which the liquid can smoothly move, and the absorbent bodies described in Patent Documents 2 and 3 are in the absorbent body. In the above-mentioned absorbing portion and the above-mentioned sheet, since the interface including the bonding means exists between the two (boundary), the liquid in the boundary portion is likely to be diffused, and it is difficult to say that the liquid can smoothly move smoothly.

In the sanitary napkin 1C, as shown in FIG. 19 to FIG. 21, at least a pair of the front sheet 2 and the absorbent core 40C are integrally recessed at a predetermined interval in a specific direction. The groove 7 is a space defined by the bottom wall portion 71 and the side wall portion 72 (the portion where the sanitary napkin 1C does not have a material to be formed). As shown in Fig. 21 (a), the groove 7 includes a pair of longitudinal grooves 7X and 7X extending in the longitudinal direction X, and two lateral grooves 7Y1 and 7Y2 extending continuously in the width direction Y. The four grooves are connected at their respective ends to form an annular groove as a whole. The pair of vertical grooves 7X and 7X are formed on the left and right sides in the longitudinal direction X of the absorbent core 40C at intervals in the width direction Y, and the longitudinal grooves 7X extend in the longitudinal direction X of the opposing portion 11 of the drain portion. It extends over the entire length and further extends to the front portion 12 and the rear portion 13, respectively. The lateral groove 7Y1 and the lateral groove 7Y2 are formed in the front portion 12 and the rear portion 13, respectively. Any one of the two lateral grooves 7Y1 and 7Y2 is formed in a shape of a horizontally long curved shape which is convexly curved outward in the longitudinal direction X in plan view, and the convex tops of the two lateral grooves 7Y1 and 7Y2 are located in the width direction. Central to Y.

As shown in Figure 21, the grooves 7 (7X, 7Y1, 7Y2) contain relatively shallow depressions. The shallow groove portion 73 and the deep groove portion 74 that is recessed relatively deep. The groove 7 is alternately connected in the longitudinal direction of the groove 7 by the shallow groove portion 73 and the deep groove portion 74, and a continuous line is formed as a whole. When the groove 7 is formed by compressing the absorbent core 40C together with the front sheet 2 by embossing, the shallow groove portion 73 is subjected to relatively weak compression in the embossing process and the bottom depth (bottom) The portion of the wall portion 71 that is shallower than the depth of the skin abutting surface 2a is a portion where the deep groove portion 74 is relatively strongly compressed during the embossing process and the bottom portion is deep. The planar shape of the shallow groove portion 73 and the deep groove portion 74 is not particularly limited, and may be a rectangle, a square, a diamond, a circle, a cross or the like.

The grooves 7 (7X, 7Y1, 7Y2) can be formed by a usual method by embossing with heat or embossing without heat or ultrasonic embossing. In other words, in the manufacturing step of the sanitary napkin 1C, after the front sheet 2 is supplied to one surface of the absorbent body 4C (absorbent core 40C having the uneven structure), the specific portion is applied from the front sheet by embossing. The 2 side is pressed (compressed) in a concave shape toward the absorber 4C side, whereby the groove 7 can be formed at the specific portion. In the groove 7, the front sheet 2 and the absorber 4C are integrated by heat fusion or the like.

The groove 7 is at least two high basis weight portions (protrusions) 41, 41 arranged in a specific direction and one low basis weight portion (non-convex) held by the two high basis weight portions 41, 41. A portion or a recess 42 is formed by being connected. That is, the groove 7 is formed so as to straddle the unevenness of the absorbent core 40C. In the present embodiment, as shown in Fig. 21 (a), in the longitudinal direction X, the excretory portion opposing portion 11 which is a portion directly receiving the excretory liquid is one of the grooves 7 and the longitudinal grooves 7X and 7X. They are respectively formed by connecting two high basis weight portions 41 and 41 adjacent in the longitudinal direction X and one low basis weight portion 42Y located between the two, and are formed to be long across The concave and convex portions of the absorbent core 40C connected in the direction X are formed. Further, in the width direction Y, in the front portion 12, the lateral groove 7Y1 which is a portion of the groove 7 is lower than the two high basis weight portions 41, 41 which are adjacent in the width direction Y, and one between the two. The base portions 42X are formed in series, and further, in the rear portion 13, the lateral grooves 7Y2 which are a part of the grooves 7 are formed in the same manner.

The positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is more important in more effectively exhibiting the absorption and diffusion effects of the excretory liquid of the present invention described below, particularly as described above, the groove 7 ( The longitudinal groove 7X) is formed so as to straddle the concavities and convexities of the absorbent core 40C connected in the longitudinal direction X and the leakage of the excretion liquid caused by the movement of the excretory liquid in the width direction Y (so-called side leakage) It is more important to prevent the effect. Therefore, in the present embodiment, as the arrangement for arranging the unevenness of the groove 7 more reliably, the low basis weight portion 42 is included in the longitudinal direction X of the sanitary napkin 1C as described above. The linear portion 42X extending in the longitudinal direction X is formed, and the groove 7 is formed to include a portion 7X having a curved portion in a plan view and extending in the longitudinal direction X. In other words, in the present embodiment, the longitudinal grooves 7X and 7X are the lengths of the sanitary napkin 1C in the opposing portion 11 of the excretory portion as shown in Fig. 21(a) as one of the grooves 7. Each of the both side portions of the direction X includes a longitudinally convex shape that is convex outward in the width direction Y of the sanitary napkin 1C. In this manner, the low basis weight portion 42X of the absorbent core 40C is formed in a linear shape that completely coincides with the longitudinal direction X, and the vertical groove 7X has a curved portion that does not completely coincide with the longitudinal direction X (partially coincident). Formed by means of at least The curved portion of the groove 7X does not completely coincide with the linear low base portion 42X extending in the longitudinal direction X in plan view, so that the longitudinal groove 7X is apt to converge across the absorbent core 40C connected in the longitudinal direction X. The way it is formed.

Further, in the present embodiment, the low basis weight portion 42 is formed so as to include the linear portion 42Y extending in the width direction Y in a plan view as described above. The groove 7 is formed to include portions 7Y1 and 7Y2 having a curved portion in a plan view and extending in the width direction Y. In other words, in the present embodiment, the lateral grooves 7Y1 and 7Y2 which are a part of the groove 7 are respectively oriented toward the sanitary napkin in the front portion 12 or the rear portion 13 of the sanitary napkin 1C as shown in Fig. 21(a) in plan view. In the longitudinal direction X of the 1C, the shape of the horizontally curved shape is convex, whereby at least the curved portions of the lateral grooves 7Y1 and 7Y2 are not linearly lower than the linear basis portion 42Y extending in the width direction Y in plan view. It is completely uniform, so that the lateral grooves 7Y1, 7Y2 are easily formed so as to straddle the unevenness of the absorbent core 40C connected in the width direction Y.

The cross section of the groove 7 in each portion of the absorbent core 40C is schematically shown in Figs. 22 to 24 . As shown in FIGS. 22 to 24, the grooves 7 (7X, 7Y1, and 7Y2) are defined by the bottom wall portion 71 and the side wall portion 72 that is erected from the bottom wall portion 71. In addition, in FIGS. 22 to 24, the illustration of the shallow groove portion 73 and the deep groove portion 74 is omitted, and the bottom wall portion 71 is described as having no step in the longitudinal direction of the groove 7. The difference is substantially flat, but actually the position of the bottom wall portion of the shallow groove portion 73 and the deep groove portion 74 in the thickness direction of the absorbent core is different, and the bottom wall portion 71 of the shallow groove portion 73 is away from the front sheet 2 Relatively close, the bottom wall portion 71 of the deep groove portion 74 is relatively far from the front sheet 2, and therefore, in the actual bottom wall portion 71 A step corresponding to the shallow groove portion 73 located at a relatively high position and the deep groove portion 74 at a relatively low position is generated.

As one of the main features of the present invention, as shown in FIG. 21, FIG. 22 and FIG. 24, a portion of the low basis weight portion 42 (42Y) constituting the side wall portion 72 is formed to have a low basis weight in the thickness direction. Aspect of the crack 78 of the portion 42. In Fig. 25, the crack 78 having a substantially elliptical shape in plan view and its vicinity are enlarged and schematically shown. The crack 78 is formed by forming the groove 7 (longitudinal groove 7X) by embossing (when the absorbent core 40C is compressed), and the absorbent core 40C is concave from the skin contact surface 4a side toward the non-skin contact surface 4b. When the shape is pressed and deformed, the low basis weight portion 42 is stretched and deformed along the deformed shape thereof, and there is no space for forming the material of the absorbent core 40C. Since the crack 78 is a space, the excretion liquid cannot move along the crack 78. The above-described behavior of the excretory fluid in the crack 78 is particularly prone to occur when the excretory fluid is a liquid having a relatively high viscosity such as menstrual blood. Therefore, it can be said that the present invention is particularly effective when applied to an absorbent article mainly for absorbing menstrual blood, such as a menstrual sanitary napkin or a sanitary pad. Thus, the crack 78 has a function of hindering the movement of the excretory liquid, and the above-described function of the crack 78 contributes to the diffusion of the excretory liquid to the front and rear of the sanitary napkin 1C as described below.

The crack 78 is formed by forming the groove 7 by embossing as described above, and is formed in the portion of the low basis weight portion 42 which constitutes the side wall portion 72, and is not formed in the high basis weight portion 41 to constitute the side wall portion 72. The part. It is presumed that the reason why the high basis weight portion 41 is relatively low is that the base portion 42 is large and is raised as a convex portion. Therefore, when the groove 7 is pressed in the thickness direction in the embossing process when the groove 7 is formed, Pressed in and easily compressed in the thickness direction, but difficult to be as low The basis weight portion 42 is stretched in the direction intersecting the thickness direction.

Further, the portion where the crack 78 is formed has a portion where the crack 78 is easily formed and a portion where the crack 78 is hard to be formed, even in the side wall portion 72 of the same low basis weight portion 42. That is, the region sandwiched by the pair of grooves 7, 7 (the pair of longitudinal grooves 7X, 7X), in other words, the side wall portion 72 on the inner side of the sanitary napkin 7 is easier than the longitudinal groove 7X (the bottom wall portion 71). The portion where the crack 78 is formed is located on the opposite side (the outer side of the napkin) via the vertical groove 7X, and the side wall portion 72 is a portion where the crack 78 is hard to be formed. In the present embodiment, the slit 78 is formed in the side wall portion 72 on the inner side of the sanitary napkin in the groove 7 (the bottom wall portion 71), and is not formed on the side wall portion 72 on the outer side of the sanitary napkin. It is presumed that when the groove 7 is formed by embossing, the region sandwiched by the pair of vertical grooves 7X and 7X is simultaneously from the upper side (the side of the front sheet 2) to the width direction Y of the region at the same time. Since the end is embossed, there is no escape portion of the stress of the absorber strain caused by the force of the press-in, so that the crack 78 is easily formed, and the groove 78 is more than the width direction Y. On the square side, since the escape portion of the stress of the absorber strain is located outside the width direction Y, it is difficult to form the crack 78. Therefore, it can be said that the existence of one of the pair of grooves 7, 7 (the longitudinal grooves 7X, 7X) formed at a certain interval is important for the formation of the crack 78.

From the viewpoint of maximizing the diffusion action of the following excretion liquid to the front and rear directions of the sanitary napkin 1C, it is preferable that the crack 78 is formed at least in the recess portion 7 (the longitudinal groove 7X). The side wall portion 72 on the inner side in the width direction Y. In the present embodiment, the crack 78 is formed not only in the excretion portion opposing portion 11, but also in the front portion 12 and the rear portion 13, and is formed not only on the side wall portion of the vertical groove 7X (the side wall portion on the inner side of the sanitary napkin) ) 72, but also The side wall portions (the side wall portions on the inner side of the sanitary napkin) 72 of each of the lateral grooves 7Y1 and 7Y2 are formed. The lateral grooves 7Y1 and 7Y2 correspond to "a pair of grooves formed at a predetermined interval" which play an important role in the formation of the cracks 78.

As for the portion of the low basis weight portion 42 where the side wall portion 72 is formed to form the crack 78, as shown in FIG. 25, at least a portion of the deep groove portion 74 is preferably in a plan view and a low basis weight portion 42. overlapping. As described above, the deep groove portion 74 is a portion that is more strongly compressed by the shallow groove portion 73 in the embossing process for forming the groove 7, and the deep groove portion 74 such as the strong compression portion is viewed from above. Designed in such a manner as to overlap with the low basis weight portion 42 to promote the breakage of the low basis weight portion 42 caused by the embossing described above, thereby facilitating the formation of the crack 78 in the portion of the low basis weight portion 42 constituting the side wall portion 72. .

Further, from the same viewpoint, as shown in FIG. 25, it is preferable that the deep groove portion 74 is located at the center portion of the groove 7 (longitudinal groove 7X) in the width direction (the direction orthogonal to the longitudinal direction of the groove 7), shallow. The groove portion 73 is located outward in the width direction of the deep groove portion 74. When the length of the shallow groove portion 73 in the width direction is L9 and the length of the deep groove portion 74 in the width direction is L10, the ratio (L9/L10) is preferably 0.05 to 0.5, more preferably It is 0.1~0.4.

In the present embodiment, the density of the high basis weight portion 41 is made higher in the high basis weight portion 41, the lower basis weight portion 42, and the groove 7 and the vicinity thereof, and the groove 7 is formed. There is a density gradient. That is, in FIG. 21(b) and FIG. 22 to FIG. 24, the density of the portion indicated by the symbols A to E is A≦B<<C<<E, and more preferably A<B<<C<D<E, The further the distance from the groove 7 (the longitudinal groove 7X) is spaced (the portion A), the closer the groove 7 is, the higher the density (the portion B and/or C) is, and the groove 7 (the bottom wall portion 71) The medium density reaches the maximum (parts D and E). Also, about the slot 7 (bottom wall portion 71), the portion D in the low basis weight portion 42 (42Y) increases the diffusibility of the liquid along the groove 7 by the density E which is slightly lower than the portion E in the high basis weight portion 41 (side leakage prevention effect) More preferably, the portion C in the vicinity of the groove 7 in the base portion 41 having a higher density is higher. The closer to the groove 7, the density density becomes higher. The density gradient is mainly caused by the embossing process described above to form the groove 7 (compression of the absorbent core 40C), and also exists in the previously formed leak-proof groove. In the absorber. Regarding the density gradient, in the present embodiment, the density of the portion C is higher than that of the portion B (B<<C), and the density in the vicinity of the groove 7 is different between the high basis weight portion 41 and the low basis weight portion 42. In addition, the "near vicinity of the groove" means the side wall portion 72 (see FIGS. 22 to 24) of the groove 7 and its adjacent portion (the portion adjacent to the side wall portion 72 in the plan view of the groove 7). The finger groove 7 (the outer surface of the side wall portion 72) is a portion within 5 mm of the direction orthogonal to the longitudinal direction of the groove 7 (the width direction of the groove 7). Usually, the boundary between the side wall portion and the adjacent portion is not clear. In the present invention, a flat acrylic plate (weight: 5 g) is placed on the skin contact surface side of the absorbent article so as to span the width direction of the groove. (on the front sheet side), when the groove below the acrylic plate is visually observed in this state, the skin contact surface in the vicinity of the groove (the adjacent portion) is brought closer to the groove in the width direction of the groove ( The front sheet) is defined as the above boundary by the portion separated from the acrylic sheet.

Thus, the vicinity of the groove 7 (longitudinal groove 7X), that is, the portions B and C are the same distance from the groove 7, but the density of the portion C located at the high basis weight portion 41 is higher than the portion B located at the low basis weight portion 42 (42Y). The reason is that since the high basis weight portion 41 has more absorbent material in the lower basis weight portion 42 before the groove 7 is formed by compressing the absorbent core 40C, the density is higher. That is, the absorption in the present embodiment The core body 40C obtains a deposit having a concavo-convex structure by depositing an absorbent material so as to include the high basis weight portion 41 and the low basis weight portion 42 as described below, and is compressed by a compressive roller or the like with a uniform compressive force. When the deposit is produced as a whole, in the above-described compression step, since the high basis weight portion 41 as the convex portion is more strongly compressed than the low basis weight portion 42 which is the non-convex portion or the concave portion, the high basis weight portion 41 ( The density of the portion C) is lower than the base portion 42 (the portion B). Thus, there is a difference in density before the formation of the groove 7 in the portion B and the portion C, and if the groove 7 is formed by compressing the portion B and the portion C, the density is reflected in the side wall portion 72 of the dividing groove 7 and its vicinity. The result is that B<<C with respect to density. Further, since the crack 78 is laterally symmetrical with respect to the portion B via the groove 7 (longitudinal groove 7X) as shown in Fig. 21(b), the vicinity of the crack 78 in the low basis weight portion 42 is separated. The density of the region within 3 mm of the periphery of the crack 78 is substantially the same as that of the portion B. Therefore, the density in the vicinity of the crack 78 is also lower than that of the portion C (the vicinity of the crack 78 in the low basis weight portion 42 is <<C).

In the sanitary napkin 1C of the present embodiment, as the absorbent core forming the groove 7, a concave-convex structure having a high basis weight portion (protrusion portion) 41 and a low basis weight portion (non-convex portion or concave portion) 42 is used. The absorbent core 40C can solve the above problem ii) of the absorbent article using the combination of the flat absorbent core and the leakage preventing groove which has no unevenness, and is in the absorbent core 4C (absorbent core) A high-density groove 7 is formed in the body 40C), but the absorber 4C is still hard to cause local hardening, and is excellent in suitability. Further, as shown in FIG. 21, when the low basis weight portion 42 is formed outside the sanitary napkin 1C (the portion outside the groove 7) than the groove 7, the leakage preventing effect of the groove 7 can be further improved, and The peripheral portion of the sanitary napkin 1C (especially the side edges of the sanitary napkin 1C along the length direction X) is given Soft touch. Further, as shown in FIG. 21, when the high basis weight portion 41 is disposed on the entire portion of the absorbent core 40C surrounded by the low basis weight portion 42, the wearer touches when the sanitary napkin 1C is worn. The touch becomes soft and provides a soft touch.

Further, in the sanitary napkin 1C of the present embodiment, the groove 7 is mainly formed by connecting two high basis weight portions 41 and 41 adjacent in a specific direction and one low basis weight portion 42 located therebetween, and It is formed so as to straddle the concavities and convexities of the absorbent core 40C, whereby the amount of the excretory fluid such as menstrual blood can be quickly absorbed and diffused, thereby solving the previous flatness without unevenness. In the above-mentioned problem i) of the absorbent article in which the absorbent core and the leakage preventing groove are combined, the leakage prevention property (side leakage prevention property) is excellent, and the size of the absorbent body can be reduced, and the absorbent article can be downsized.

When the absorption and diffusion of the excretion liquid in the sanitary napkin 1C of the present embodiment are described with reference to Fig. 21 (b), the excretion fluid W such as menstrual blood excreted by the wearer of the sanitary napkin 1C is usually opposed by the excretory portion. The central portion of the width direction Y of the portion 11 is caught, and moves from the skin abutting surface (the skin abutting surface 2a of the top sheet 2) toward the groove 7 (longitudinal groove 7X) in the width direction Y, for example, in FIG. 21 In (b), the part A (the vicinity of the center portion in the width direction Y of the excretion portion opposing portion 11) faces the crack 78 (near the groove 7 in the low basis weight portion 42) along the various constituent members of the sanitary napkin 1C. (Front sheet 2, absorbent core 40C, etc.) moves. Further, since the crack 78 is a space in which the material for forming the absorbent core 40C (the material for forming the sanitary napkin 1C) such as the absorbent material is not present as described above, the excrement W reaching the vicinity of the crack 78 cannot be followed. The crack 78 traverses it, and therefore, as shown in Fig. 21 (b), the excrement W follows the crack 78. The crack 78 is avoided in the vicinity, and moves to the vicinity of the groove 7 in the high basis weight portion 41, that is, the portion C (the portion C on the inner side in the width direction Y of the groove 7). Further, as described above, the vicinity of the crack 78 in the low basis weight portion 42 is lower in density than the portion C located at a position symmetrical with respect to the slit 78 via the groove 7 (longitudinal groove 7X). Since B<<C), it is easy to exert a capillary force between the vicinity of the crack 78 and the portion C, and the movement of the excretory fluid W to the portion C is also promoted by the capillary force. In this manner, the excretion liquid W moves in the vicinity of the groove 7 and in the width direction Y from the groove 7, and moves along the groove 7 in the front-rear direction of the sanitary napkin 1C, so that the opposite portion 11 from the excretion portion is promptly elongated in the longitudinal direction X. Diffusion.

The excretion liquid W is rapidly absorbed and held by the high basis weight portion 41 in the vicinity of the groove 7 and moved in the width direction Y from the groove 7 to the portion C, exceeding the high basis weight portion 41. As shown in FIG. 24, the portion of the absorption capacity is moved to a portion E (the bottom wall portion 71 of the dividing groove 7 in the high basis weight portion 41) which is located outside the width portion Y of the portion C. The portion E is a portion that is most compressed when the groove 7 is formed, and since the density is much higher than the portion C adjacent in the width direction Y, the excretion liquid W is hard to move from the portion E to the portion C, so that it is difficult to cause excretion. The liquid W moves beyond the groove 7 and moves outside the width direction Y of the sanitary napkin 1C. The excretion liquid W that has moved to the portion E via the portion C does not leak to the outer side of the groove 7, but is moved by the groove 7 to the adjacent portion D (the bottom wall portion 71 of the dividing groove 7 in the low basis weight portion 42), Further, it moves to another portion E adjacent thereto. Thus, the excretory fluid W moving in the tank 7 is mainly absorbed and held by the high basis weight portion 41 during its movement.

As described above, in the sanitary napkin 1C of the present embodiment, the excretion liquid discharged to the central portion in the width direction Y of the excretion portion opposing portion 11 is located in the vicinity of the vertical groove 7X and the vertical groove 7X and is located further in the width than the vertical groove 7X. Both of the portions in the direction Y are rapidly diffused in the front and rear directions of the sanitary napkin 1C, and are rapidly absorbed and held mainly by the high basis weight portion 41 in the middle of the above diffusion. Therefore, the sanitary napkin 1C of the present embodiment can rapidly diffuse the excreted excretion fluid by utilizing the diffusion and absorption of the excretion liquid in combination with the absorbent body 4C (absorbent core 40C) and the groove 7. It is absorbed, so that it is difficult to produce side leakage, and the wearer's discomfort caused by wetting can be eliminated. From the viewpoint of more effectively exerting the effect of the sanitary napkin 1C, it is preferable to set the size and the like of each portion as follows.

The ratio (S41/S42) of the basis weight S41 of the high basis weight portion 41 of the absorbent core 40C to the basis weight S42 of the low basis weight portion 42 is preferably 1.25 or more, more preferably 3 or more, and more preferably 10 Hereinafter, it is more preferably 6 or less.

The basis weight S41 of the high basis weight portion 41 is preferably 100 g/m ² or more, more preferably 150 g/m ² or more, and further preferably 600 g/m ² or less, more preferably 500 g/m ² or less. The basis weight S42 of the low basis weight portion 42 is preferably 10 g/m ² or more, more preferably 30 g/m ² or more, and further preferably 150 g/m ² or less, more preferably 100 g/m ^{2 .} the following.

The ratio (T41/T42) of the thickness T41 of the high basis weight portion 41 to the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and is preferably 20 or less, more preferably 10 or less.

The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and further preferably 10 mm or less, more preferably 8 mm or less, and low basis. The thickness T42 of the heavy portion 42 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 5.0 mm or less, more preferably 3.0 mm or less.

The width L1 of the low basis weight portion 42 (see Fig. 21 (a)) is preferably 0.5 mm or more, more preferably 1 mm or more, and further preferably 7.5 mm or less, more preferably 5 mm or less. In the low basis weight portions 42X and 42Y, the width L1 may be the same or different.

The size of the high basis weight portion 41 as shown in Fig. 21(a) in the plan view differs depending on the type and use of the absorbent article, and the length L2 in the longitudinal direction X in the sanitary napkin such as the sanitary napkin 1C (refer to 21(a)) is preferably 5 mm or more, more preferably 10 mm or more, and is preferably 50 mm or less, more preferably 30 mm or less, and a length L3 in the width direction Y (refer to Fig. 21 (a)). It is preferably 3 mm or more, more preferably 5 mm or more, and more preferably 30 mm or less, more preferably 20 mm or less.

Preferably, the area of the high basis weight portion 41 is preferably 5 or more, more preferably 10 or more, per 50 cm ² , and more preferably 70 or less, more preferably 60 or less.

The width L5 (see Fig. 21 (b)) of the grooves 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and is preferably 5.0 mm or less, more preferably 4.0 mm or less.

The depth L6 (refer to Fig. 23) of the groove 7 is preferably 0.5 mm or more, more preferably 1.0 mm. Further, the depth L6 means the depth of the deep groove portion 74 which is the deepest portion of the groove 7. The depth of the shallow groove portion 73 is preferably less than 0.5 mm, more preferably less than 1.0 mm.

The length L7 of the crack 78 along the length of the groove 7 (7X, 7Y1, 7Y2) (Refer to Fig. 25) It is preferable that the length of the low basis weight portion 42 in which the crack 78 is formed is along the length direction (e.g., the length of the low basis weight portion 42Y in the longitudinal direction of the groove 7X in Fig. 25). It is 20 to 90%, more preferably 40 to 80%.

The length L8 (see FIG. 25) of the slit 78 in the width direction of the groove 7 (7X, 7Y1, 7Y2) is preferably equal to or less than the above length L7 (L7 ≧ L8).

Further, the size of each portion of the groove 7 may be measured by using a ruler or the like, but it is preferably measured using a digital microscope. For example, the groove 7 can be enlarged and photographed using a digital microscope VHX-1000 manufactured by KEYENCE, and the size of each portion can be measured. The width L5 of the groove 7 is measured on the bottom surface of the groove 7. Further, the depth L6 of the groove 7 is obtained by measuring the cross section of the groove 7 by a digital microscope.

When the materials for forming the respective portions of the sanitary napkin 1C are described, the front sheet 2 and the back sheet 3 can be used without any particular limitation, and various materials previously used in the technical field can be used. As the front sheet 2, for example, a liquid permeable sheet such as a non-woven fabric or an apertured film can be used. As the back surface sheet 3, for example, a resin film which does not have moisture permeability, a resin film which has fine pores and has moisture permeability, a nonwoven fabric such as water-repellent nonwoven fabric, a laminate of these and other sheets, or the like can be used. Further, as the side sheet 5, various materials previously used in the technical field can be used without particular limitation, and for example, a water-repellent non-woven fabric or a resin film-made sheet can be used.

As the absorbent material which is a material for forming the absorbent core 40C, various materials previously used in the art can be used without particular limitation. For example, as a fibrous material, natural fibers such as wood pulp, cotton, and hemp can be used; a composite fiber of synthetic resin such as polyethylene or polypropylene; acetate or hydrazine Semi-synthetic fibers, etc. Further, as the absorbent material, in addition to the fibrous materials, various shapes of water-absorbent polymers such as pellets may be used.

The absorbent body (absorbent core) of the third aspect of the invention can be produced by the same method as the method for producing the absorbent body (absorbent core) of the first invention. The absorbent body 4C (absorbent core 40C) of the third invention can be produced in the same manner as the absorbent body 4A (absorbent core 40A) of the first invention, using the apparatus for producing an absorbent body shown in Fig. 7 . In the method for producing the absorbent body 4C (absorbent core 40C) according to the third aspect of the invention, a description will be given of a method for producing the absorbent body 4A (absorbent core 40A) according to the first aspect of the invention.

The present invention (third invention) is not limited to the above embodiment. For example, in the above-described embodiment, the low basis weight portion 42 is biased against the skin contact surface 4a side in the thickness direction of the absorbent core 40C, but may be opposite to the non-skin contact surface 4b side. . In this case, the high basis weight portion 41 protrudes toward the skin contact surface 4a side, and the absorbent core 40C as a whole is opposite to the upper and lower sides shown in FIG.

Further, the low basis weight portions 42 (42X, 42Y) which are linear in plan view may not be formed on the entire absorbent core 40C as shown in FIG. 21 (to span the front portion 12, the discharge portion facing portion 11 and the rear portion). The portion 13 is formed as long as it is formed in at least a pair of grooves 7, 7 (longitudinal grooves 7X, 7X) and a vicinity (slot peripheral region) of the excretion portion opposing portion 11 (excretion portion pair) The inner portion of the width direction of the portion 11 may be used. Further, the planar shape of the low basis weight portion 42 is not limited to a linear shape as in the above embodiment, and may be curved.

Further, in the absorbent core 40C, the high basis weight portion 41 may be arranged in a zigzag shape. That is, a plurality of high basis weights are arranged at a specific interval in the longitudinal direction X. When a portion of the high basis weight portion is formed in the portion 41 and a plurality of the high basis weight portions are arranged at a predetermined interval in the width direction Y, the high basis weight portion 41 in the high basis weight portion adjacent to each other The distance between them can also be staggered. In other words, the high basis weight portion 41 can also project the high basis weight portion 41 in the specific high basis weight row in the direction orthogonal to the high basis weight portion row (width direction Y), and the adjacent high base. The projection images of the heavy portion 41 are arranged in an inconsistent manner. In this way, the grooves 7 (the lateral grooves 7Y1 and 7Y2) extending in the width direction Y are not convexly curved outward in the longitudinal direction X of the sanitary napkin 1C as in the above-described embodiment (see FIG. 21). The shape of the horizontally long shape is formed (for example, even if the lateral grooves 7Y1, 7Y2 are formed in a linear shape extending in the width direction Y), the lateral grooves 7Y1, 7Y2 and the low basis weight portion 42 can be prevented from completely matching each other.

Further, as described above, the groove 7 and the two high basis weight portions 41 and 41 arranged in a specific direction (the longitudinal direction X or the width direction Y of the sanitary napkin 1C) and the two high basis weight portions 41 are provided. A method in which one of the low basis weight portions 42 held by 41 is connected, in other words, the groove 7 and the low basis weight portion 42 of the absorbent core 40C are not completely matched, except that the groove 7 is provided as in the above embodiment. In addition to the method of forming the shape in which the low basis weight portion 42 is formed in a curved shape in a plan view and the shape of the low basis weight portion 42 in a plan view, the following method may be employed: a) A low basis weight portion 42 having a relatively small size disposed around the large base portion 41; b) as a high basis weight portion 41 combined with the low basis weight portion 42, a polygonal shape having a shape of a pentagon or more in plan view is used alone One type of the high basis weights 41 or a combination of two or more types; c) the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 are extended) and the direction in which the low basis weights are formed (linear low basis) The angle formed by the extension direction of the heavy part is set to 30~60°.

Moreover, although one of the application examples of the absorbent article of the present invention (third invention) is a menstrual sanitary napkin, the present invention can also be applied to, for example, a disposable diaper, an incontinence pad, a sanitary pad, and the like.

Hereinafter, a preferred embodiment of the absorbent article according to the fourth aspect of the invention will be described with reference to Figs. 26 to 29 . The absorbent article 1D (hereinafter also referred to as "absorbent article 1D") of the present embodiment includes a menstrual napkin, a disposable diaper, an incontinence pad, and the like.

The absorbent article 1D includes a vertically long absorbent body 10 including a liquid-permeable front sheet 2 disposed on the side facing the skin surface (the side facing the skin side of the wearer). A back sheet 3 that is not liquid-permeable to the skin surface (the side opposite to the skin side of the wearer), and an absorbent body 4D that is long between the sheets 2 and 3. As shown in FIG. 26, the absorbent article 1D is formed to be bilaterally symmetrical with respect to a center line CL extending in the longitudinal direction of the absorbent body 10. Further, the "X" direction shown in each drawing is a direction parallel to the center line CL, and is the same direction as the longitudinal direction of the absorbent body 10. Moreover, the "Y" direction shown in each drawing is a direction orthogonal to the center line CL, and is the same direction as the width direction of the absorptive main body 10.

Any of the front sheet 2 and the back sheet 3 forming the absorbent body 10 has a longitudinally long shape in the longitudinal direction (X direction) of the absorbent body 10 as shown in FIG. And having a contour that conforms to the contour of the absorbent body 10. As described above, in the absorbent sheet 1D, the front sheet 2 and the back sheet 3 are formed in the same shape and the same size. The front sheet 2 and the back sheet 3 are covered as shown in Figs. 26 and 27, respectively. The entire surface of the absorbent body 4D facing the skin surface side and the entire surface not facing the skin surface side, and extending portions extending from the periphery of the absorbent body 4D, the extension portions being joined by heat embossing, thereby The peripheral edge portion forms a peripheral seal portion 5.

Further, in the absorbent article 1D, the peripheral seal portion 5 is formed by heat embossing, but may be formed by ultrasonic sealing, or may be formed by an adhesive such as hot melt.

The absorber 4D is configured to include an absorbent core 40D including an absorbent material 45 (a fibrous material such as pulp or a water-absorbent polymer). The absorber 4D in the present embodiment is configured by covering the absorbent core 40D with a core material (not shown) including a toilet paper or a water-permeable nonwoven fabric. The absorbent core 40D may include only a fibrous material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42 described below, or may retain a water-absorbing polymer between the fibrous materials. Between the front sheet 2 and the absorber 4D, the absorber 4D and the back sheet 3 may be bonded to each other by an adhesive (hot melt adhesive or the like) applied by patterning such as dots, spirals, or stripes.

In the fourth aspect of the invention, the absorber 4D includes a high basis weight portion 41 having a relatively high basis weight, and a low basis weight portion 42 adjacent to the high basis weight portion 41 and having a relatively low basis weight. As will be described in detail, in the absorbent article 1D, as shown in Figs. 27 and 28, the absorbent core 40D constituting the absorbent body 4D includes a relatively high absorbent base material 41 and a relatively high absorbent base material 41. Fewer low base weights 42 (42X, 42Y). As shown in Fig. 27, the outer diameter of the absorbent core 40D is uniform. As shown in FIGS. 27 and 28, the absorptive core 40D has a plurality of linear lines extending in the longitudinal direction X (continuous linear shape). The low basis weight portion 42X and the low basis weight portion 42Y which is linear (continuously linear) extending in the width direction Y. As shown in FIGS. 27 and 28, the low basis weight portion 42 is a linear low base portion 42X extending in the longitudinal direction X and a linear low basis weight portion 42Y extending in the width direction Y. Further, the entire shape is formed in a lattice shape, and the high basis weight portion 41 is disposed at a portion (the position of the hole of the lattice) partitioned by the linear low basis weight portions 42X and 42Y. The plurality of linear low basis weight portions 42X are formed to extend over the entire length X of the absorbent core 40D, and the plurality of linear low basis weight portions 42Y extend throughout the width direction of the absorbent core 40D. The full length extends to form.

In the fourth aspect of the invention, as shown in FIG. 27, the high basis weight portion 41 and the low basis weight portion 42 are integrally formed, and are formed as a high basis weight portion 41 on the side of the back sheet 3 of the absorber 4D. The convex portion and the concave portion as the low basis weight portion 42 are alternately arranged in a concave-convex structure, and the low basis weight portion 42 is biased against the front sheet 2 side of the absorbent body 4D. Here, the "integral molding" means that the high basis weight portion 41 and the low basis weight portion 42 are not integrated with each other without being joined by a joining means such as an adhesive or heat fusion, and are integrally formed of the same material. When the high basis weight portion 41 and the low basis weight portion 42 are integrally formed in this manner, the continuity of the body fluid can be smoothly moved. As shown in Fig. 27, the low basis weight portion 42 is biased against the front sheet 2 side in the thickness direction T of the absorbent article 1D (the skin facing side of the absorbent body 4D). Further, since the low basis weight portion 42 is biased against the front sheet 2 side in the thickness direction T as described above, the high basis weight portion 41 protrudes toward the opposite side of the front sheet 2 side as shown in FIG. 27, that is, The side of the back sheet 3 in the thickness direction T (the side of the absorber 4D not facing the skin side) protrudes. In the absorbent core 40D, the side of the absorbent core 40D facing the skin surface (the side of the front sheet 2 side) contains a low base. The heavy portion 42 is formed to be substantially substantially flat. Further, in the absorbent core 40D, a plurality of high basis weight portions 41 (convex portions) formed by protrusions are formed on the non-facing surface (surface on the back sheet 3 side) of the absorbent core 40D. A concavo-convex structure formed by the low basis weight portion 42 (concave portion) between the high basis weight portions 41 and 41.

In the absorbent article 1D formed as described above, as shown in FIG. 27, the low basis weight portion (concave portion) 42 is recessed toward the front sheet 2 side, and the high basis weight portion (protrusion portion) 41 is directed to the back sheet 3 The side is convex. In other words, the concave portion recessed toward the front sheet 2 in the uneven structure of the absorbent body 4D is mainly formed of the low basis weight portion 42, and the convex portion protruding toward the back sheet 3 side in the uneven structure of the absorbent body 4D is mainly composed of high base. The heavy portion 41 is formed. Here, the phrase "the concave portion is mainly formed by the low basis weight portion 42" means that the high basis weight portion 41 including the vicinity of the boundary between the low basis weight portion 42 and the high basis weight portion 41 forms a part of the concave portion, and similarly The term "the above-mentioned convex portion is mainly formed by the high basis weight portion 41" means a case where the low basis weight portion 42 including the vicinity of the boundary between the high basis weight portion 41 and the low basis weight portion 42 forms a part of the convex portion.

When the absorbent article 1D is used in the case of menstrual sanitary napkins, it is easy to bend in conformity with the shape of the wearer's body, and in view of the smoothness of the surface, the wearer is provided with an excellent wearing feeling, and the low base is used. The width L1 of the heavy portion 42 is preferably 0.5 mm or more, and is preferably 2.5 mm or less, more preferably 1.5 mm or less.

Further, in the case where the absorbent article 1D is used for a disposable diaper, if the liquid is temporarily obtained in consideration of the low-density portion, the liquid is quickly extracted from the surface, and it is necessary to design it slightly larger than the menstrual period. Cotton design value In view of the above, the width L1 of the low basis weight portion 42 is preferably 1.0 mm or more, and is preferably 7.0 mm or less, more preferably 5.0 mm or less.

Further, in the low basis weight portion 42X in the longitudinal direction X and 42Y in the width direction Y, the width L1 may be the same or different. Moreover, the width L1 is a measured value at the position of the bottom of the concave portion in the uneven structure of the absorbent body 4D.

When the absorbent article 1D is used for the menstrual sanitary napkin, the basis weight of the low basis weight portion 42 (42X, 42Y) forming the concave portion is preferably 20 g/m ² or more, more preferably 50 g/m ² or more, and It is preferably 200 g/m ² or less, more preferably 150 g/m ² or less. Further, the basis weight of the high basis weight portion 41 forming the convex portion is preferably 50 g/m ² or more, more preferably 100 g/m ² or more, and further preferably 500 g/m ² or less, more preferably 400 g/m ^{2 .} the following. Further, the thickness of the low basis weight portion 42 (concave portion) is 80% or less, preferably 70% or less, of the thickness of the high basis weight portion 41 (convex portion), and the thickness of the low basis weight portion 42 (recessed portion) is preferably 0.3. It is more than 0.5 mm, more preferably 0.5 mm or more, and further preferably 3.0 mm or less, more preferably 2.0 mm or less. Further, the thickness of the high basis weight portion 41 (protrusion portion) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and further preferably 7.0 mm or less, more preferably 5.0 mm or less.

In the case where the absorbent article 1D is used for a disposable diaper, since the low basis weight portion 42 (42X, 42Y) forming the concave portion functions to temporarily obtain a liquid, and the liquid is quickly extracted from the surface, the basis weight thereof Preferably, it is designed to be slightly larger than the design value of the menstrual sanitary napkin. From this point of view, the basis weight is preferably 30 g/m ² or more, more preferably 50 g/m ² or more, and further preferably 300 g/m ^{2 .} Hereinafter, it is more preferably 200 g/m ² or less. Further, the basis weight of the high basis weight portion 41 forming the convex portion is preferably 100 g/m ² or more, more preferably 150 g/m ² or more, and further preferably 700 g/m ² or less, more preferably 500 g/m ^{2 .} the following. Further, the thickness of the low basis weight portion 42 (concave portion) is 80% or less, preferably 70% or less, of the thickness of the high basis weight portion 41 (convex portion), and the thickness of the low basis weight portion 42 (recessed portion) is preferably 0.3. More than mm, more preferably 0.5 mm or more, and further preferably 5.0 mm or less, more preferably 3.0 mm or less. Further, the thickness of the high basis weight portion 41 (protrusion portion) is preferably 1.0 mm or more, more preferably 1.5 mm or more, and further preferably 9.0 mm or less, more preferably 7.0 mm or less.

Further, the thickness of the high basis weight portion 41 (the convex portion) and the low basis weight portion 42 (42X, 42Y) (the concave portion) is such that the absorbent article 1D is oriented in the width direction shown in Fig. 29 (a) with a sharp razor. (Y direction) or the length direction X is cut, and the cross section of the sample obtained by the cutting is measured. The thickness of the high basis weight portion 41 (protrusion portion) is a value measured at the position of the thickest portion of the convex portion, and the thickness of the low basis weight portion 42 (recessed portion) is measured at the thinnest position in the concave portion. value. In the case where it is difficult to measure with the naked eye, for example, a cross section of the sample obtained by the cutting may be observed and measured at a magnification of 25 to 50 times using a microscope (VHX-1000 manufactured by KEYENCE Corporation).

The basis weights of the high basis weight portion 41 and the low basis weight portion 42 were measured as follows.

<Method for measuring basis weight>

The method of measuring the basis weight of the high basis weight portion 41 and the low basis weight portion 42 is as follows.

The absorber 4D is cut at a boundary portion between the high basis weight portion 41 and the low basis weight portion 42 using a single-edged razor manufactured by FEATHER. Using an electronic balance (electronic balance GR-300 manufactured by A & D Co., Ltd., accuracy: 4 digits after the decimal point), 10 small pieces of the high basis weight portion 41 obtained by cutting were respectively measured and averaged to obtain a high basis. The weight of one small piece of the weight 41. The weight obtained The basis weight of the high basis weight portion 41 is calculated by dividing the area of each of the small pieces of the high basis weight portion 41 calculated from the design size of the high basis weight portion 41.

Next, along the boundary line of the high basis weight portion 41 and the low basis weight portion 42 extending in the longitudinal direction of the product, the length is 100 mm, and the width is matched with the design size of the width of the low basis weight portion 42, and is manufactured by FEATHER. For a single-edged razor, a sample of five thin stripe-shaped low basis weight portions 42 was cut. Using the electronic balance (electronic balance GR-300 manufactured by A&D Co., Ltd., accuracy: 4 digits after the decimal point), the obtained five samples were respectively measured and averaged to obtain the weight of one sample of the low basis weight portion 42. . The basis weight of the low basis weight portion 42 is calculated by dividing the obtained weight by the area of the sample of the low basis weight portion 42.

In the absorbent body 4D of the absorbent article 1D, since the high basis weight portion 41 has more absorbent material in the lower basis weight portion 42, the high basis weight portion 41 and the low basis weight portion 42 (42X, 42Y) are present. The ratio is formed to a high density.

When the absorbent article 1D is used for the menstrual napkin, the ratio of the density D41 of the high basis weight portion 41 to the density D42 of the low basis weight portion 42 (D41/D42) is preferably 1/4 to 3/4. More preferably 1/3~2/3. Further, the density of the low basis weight portion 42 forming the concave portion is 0.03 to 0.18 g/cm ³ , preferably 0.05 to 0.15 g/cm ³ . Further, the density of the high basis weight portion 41 forming the convex portion is 0.05 to 0.50 g/cm ³ , preferably 0.10 to 0.40 g/cm ³ .

When the absorbent article 1D is used in a disposable diaper, the ratio of the density D41 of the high basis weight portion 41 to the density D42 of the low basis weight portion 42 (D41/D42) is preferably 1/5 to 3/4. More preferably 1/4~2/3. Further, the density of the low basis weight portion 42 forming the concave portion is 0.01 to 0.20 g/cm ³ , preferably 0.03 to 0.15 g/cm ³ . Further, the density of the high basis weight portion 41 forming the convex portion is 0.05 to 0.50 g/cm ³ , preferably 0.10 to 0.40 g/cm ³ .

The density of the high basis weight portion 41 and the low basis weight portion 42 was measured as follows.

<Method for measuring density>

The cross section corresponding to FIG. 27 of the absorber 4D was observed using a microscope VHX-1000 manufactured by KEYENCE, and the thicknesses of the high basis weight portion 41 and the low basis weight portion 42 were measured.

The density of the high basis weight portion 41 and the low basis weight portion 42 is calculated by dividing the basis weight of the high basis weight portion 41 and the low density portion 42 obtained by the above method by the measured thickness.

In the absorbent article 1D, as shown in FIG. 28, the corner portion of the high basis weight portion 41 which forms the convex portion in plan view is formed in an arc shape. Specifically, as shown in FIG. 28, the high basis weight portion 41 of the absorbent article 1D has an arc shape at four corners in plan view, and the radius of curvature of each corner is preferably 0.5 mm or more, more preferably 1.0 mm or more. It is preferably 5.0 mm or less, more preferably 3.0 mm or less. When the corner portion of the high basis weight portion 41 is formed in an arc shape, the high basis weight portion 41 of the cylindrical recess portion 51 formed by depositing the fibers on the rotary cylinder 50 is transferred to the mesh belt 75. In the case of the upper portion, it is easy to rapidly transfer from the cylindrical recess 51, and the formability of the high basis weight portion 41 is improved. Further, in the absorbent article 1D, the high basis weight portion 41 is formed in an arc shape in a plan view at a corner portion, but may not be in an arc shape, and the high basis weight portion 41 may have a rectangular shape or an elliptical shape in plan view. Wait.

When the absorbent article 1D is used for the menstrual sanitary napkin, as shown in FIG. 28, the length L2 of the longitudinal direction X of the high basis weight portion 41 forming the convex portion is preferably 10 mm or more, more preferably 15 mm or more, and preferably It is 30 mm or less, more preferably 25 mm or less. Further, the length L3 in the width direction Y is preferably 5 mm or more, more preferably 7.5 mm or more, and is preferably 25 mm or less, more preferably 20 mm or less.

When the absorbent article 1D is used for the disposable diaper, the length L2 of the longitudinal direction X is preferably 10 mm or more, more preferably 20 mm or more, and more preferably 70 mm. Hereinafter, it is more preferably 60 mm or less. Further, the length L3 in the width direction Y is preferably 5 mm or more, more preferably 10 mm or more, and is preferably 50 mm or less, more preferably 40 mm or less.

In the fourth aspect of the invention, as shown in FIG. 27 and FIG. 28, the recessed portion (low basis weight portion) 42 and the back sheet 3 which are recessed toward the front sheet 2 side in the uneven structure of the absorber 4D are used. The formed space 6 extends continuously at least in the longitudinal direction X. As described above, in the absorbent article 1D, as shown in FIGS. 27 and 28, the low basis weight portions 42 (42X, 42Y) are formed in a lattice shape as a whole, and the high basis weight portion 41 is disposed at the position of the hole of the lattice. The concave portion (low basis weight portion 42) is disposed to surround the convex portion (high basis weight portion 41). As described above, in the absorbent article 1D, as shown in FIGS. 27 and 28, a plurality of spaces formed by a plurality of continuous linear portions (low basis weight portions 42X) extending in the longitudinal direction X and the back sheet 3 are formed. 6X is continuously extended in the longitudinal direction X, respectively, and a plurality of recesses (low basis weight portion 42Y) extending in the width direction Y and a plurality of spaces 6Y formed by the back sheet 3 are respectively in the width direction Y. Extend continuously.

It is believed that in the sanitary napkins, the humidity in the dress is especially increased by the absorption of menstrual blood. In the disposable diapers, the humidity in the dress is especially increased by the absorption of urine. high.

In the menstrual sanitary napkin, in the case of effectively reducing the humidity in the dress when used, when the absorbent article 1D is used for the menstrual napkin, the space extending continuously in the longitudinal direction X is 6X (and It is preferable that the number of the low basis weight portions 42X is equal to or greater than two, and more preferably three or more.

In disposable diapers, the amount of urine absorbed by each disposable diaper is usually greater than the amount of menstrual blood absorbed by each period of sanitary napkin, and the width of the absorbent body of the disposable diaper is generally higher than that of the menstrual napkin. It is wide, so that the space in which the absorbent article 1D is continuously used in the longitudinal direction X is 6X (and low) in the case where the absorbent article 1D is used for the disposable diaper from the viewpoint of further effectively reducing the humidity in the dressing at the time of use. Preferably, the number of the basic weight portions 42X is three or more, and more preferably four or more.

For the same reason, when the absorbent article 1D is used for the menstrual napkin, the space 6Y continuously extending in the width direction Y (the same number as the low basis weight portion 42Y) is preferably disposed. More than 8 or more, more preferably 10 or more. When the absorbent article 1D is used for a disposable diaper, the space 6Y continuously extending in the width direction Y (the same number as the low basis weight portion 42Y) is preferably arranged in more than 10 pieces, more preferably There are more than 12 configurations.

In the absorbent article 1D, as shown in Fig. 29 (a), the absorbent sheet 4D corresponds to the concave portion (low basis weight portion 42) of the uneven structure on the side of the back sheet 3 on the side of the front sheet 2 of the absorbent core 4D. There is a front side concave portion 43 that is recessed toward the back sheet 3 side. As will be described in detail, as described above, in the absorbent article 1D, As shown in FIG. 28, the concave portion (low basis weight portion 42) includes a plurality of concave portions (low basis weight portions 42X) extending in the longitudinal direction X and continuous linear shapes extending in the width direction Y. One recess (low basis weight 42Y). Therefore, the absorbent body 4D has a back surface on the surface of the front sheet 2 in the absorbent article 1D corresponding to a plurality of continuous linear portions (low basis weight portions 42X) extending in the longitudinal direction X. a plurality of front side recesses 43X (see FIGS. 28 and 29(a)) in which the sheet 3 is recessed, and each of the front side recesses 43X extends in a straight line in the longitudinal direction X, and extends in the width direction Y, respectively. The plurality of concave portions (low basis weight portions 42Y) having a continuous linear shape have a plurality of front side recesses 43Y (see FIG. 28) recessed toward the back sheet 3 side on the surface on the side of the front sheet 2 (see FIG. 28). The undercut portion 43Y extends in a continuous straight line in the width direction Y. As shown in FIG. 28, the number of the low basis weight portions 42X (spaces 6X) is the same as the number of the front side recesses 43X, and the number of the low basis weight portions 42Y (spaces 6Y) is the same as the number of the front side recesses 43Y.

As described above, the absorbent body 4D of the absorbent article 1D has the front side concave portions 43X and 43Y corresponding to the concave-convex portions (low basis weight portions 42X and 42Y) of the uneven structure as shown in Fig. 29 (a), but absorbs The sexual article 1D is easily deformed toward the wearer's skin to improve the suitability, and the viewpoint of preventing leakage is further increased by increasing the area of the non-skin contact surface by the wearer's skin contact surface of the wearer 4D. The depth d2 of the concave portion (low basis weight portions 42X, 42Y) is deeper than the depth of the front side concave portions 43X, 43Y from the viewpoint of preventing the liquid absorbed by the non-skin contact surface from escaping from the non-skin contact surface. D1 deepens. The depth d2 of the concave portion (low basis weight portions 42X, 42Y) is preferably three times or more the depth d1 of the front side concave portions 43X and 43Y, and more preferably the depth d1. More than 5 times. The depth d1 of the front side recessed portions 43X and 43Y is preferably 2 to 20%, more preferably 3 to 15%, of the thickness of the convex portion (high basis weight portion 41) in the absorbent body 4D (absorbent core 40D). The depth d2 of the concave portion (low basis weight portions 42X and 42Y) and the depth d1 of the front side concave portions 43X and 43Y are the same as those of the high basis weight portion 41 (convex portion) and the low basis weight portion 42 (recessed portion). The method was measured.

As shown in Fig. 29 (a), when the absorbent body 4D (absorbent core 40D) of the absorbent article 1D is cross-sectionally viewed in a cross section in the width direction (Y direction), the length of the lower side L5 of the back sheet 3 side is The length of the upper side L4 of the side of the front side sheet 2 is longer.

In particular, when the absorbent article 1D is used for menstrual sanitary napkins, the length of the lower side L5 is preferably 1.5 of the length of the upper side L4 from the viewpoint of effectively reducing the humidity generated by the menstrual blood absorbed by the absorbent body 4D. ~5 times, more preferably 2~4 times.

Further, particularly in the case where the absorbent article 1D is used for a disposable diaper, the length of the lower side L5 is preferably the upper side L4 from the viewpoint of effectively reducing the humidity generated by the urine absorbed by the absorbent body 4D. The length is 1.5 to 7 times, more preferably 2 to 5 times.

Further, the length of the lower side L5 is measured to be the same as the thickness of the high basis weight portion 41 (protrusion portion) and the low basis weight portion 42 (recessed portion). The lower side L5 is a contour path, and the lower side L5 is a length in the width direction (Y direction) of the convex portion (high basis weight portion 41) of the uneven structure on the side of the back sheet 3, and the convex portion is formed. The length of the pair of opposing walls in the Y direction of the heavy portion 41) and the width direction in the bottom of the concave portion (low basis weight portion 42) of the uneven structure (Y The length of the direction) and the sum of these is added to calculate the length. The upper side L4 also measures the contour path length in the same manner as the lower side L5.

As described above, the space 6 formed by the concave portion (low basis weight portion 42) of the uneven structure on the side of the back sheet 3 and the back sheet 3 is contained in the absorbent article 1D as shown in Figs. 27 and 28, and is included in the length. A plurality of spaces 6X extending continuously in the direction X and a plurality of spaces 6Y extending continuously in the width direction Y. The low basis weight portion 42 in the space 6X extending in the longitudinal direction X and the space 6Y extending in the width direction Y is in the absorbent article 1D, as shown in Fig. 29 (b), in the intersection region 6XY The thickness of the central portion becomes the thinnest. As will be described in detail, as shown in FIG. 29(b), the low basis weight portion 42X (concave portion) formed in the space 6X extending continuously in the longitudinal direction X is formed in an arc shape at the bottom of the concave portion when viewed in cross section. Further, the low basis weight portion 42Y (concave portion) formed in the space 6Y continuously extending in the width direction Y is also formed in an arc shape at the bottom of the concave portion when viewed in cross section, so that the space 6X and the width direction Y in the longitudinal direction X are formed. In the intersection region 6XY of the space 6Y, the central portion is most recessed toward the side of the front sheet 2, and the thickness of the central portion is thinner than the boundary of the adjacent convex portion (high basis weight portion 41) in the low basis weight portion 42. The thinnest is the thickness. With such a configuration, the absorbed liquid can quickly permeate into the space 6X in the longitudinal direction X and the space 6Y in the width direction Y via the intersection region 6XY, and the liquid is quickly absorbed from the front sheet 2, thereby Provides an excellent dry feel to the wearer.

In particular, in the absorber 4D of the absorbent article 1D, as described above, the front side concave portion 43X and the low basis weight of the concave portion forming the width direction Y are formed corresponding to the low basis weight portion 42X forming the concave portion in the longitudinal direction X. Department 42Y relative The front side recessed portion 43Y has a front side recessed portion 43Y, and as shown in Fig. 29(b), the front side recessed portion 43X is formed in an arc shape at the bottom of the front side recessed portion 43X when viewed in cross section, and the front side recessed portion 43Y is also formed in the recessed portion when viewed from the cross section. The bottom is formed in an arc shape. Therefore, in the intersection of the front side concave portion 43X in the longitudinal direction X and the front side concave portion 43Y in the width direction Y, the central portion is most recessed toward the back sheet 3 side. Therefore, the distance between the central portion in the intersection of the front side recessed portion 43X and the front side recessed portion 43Y, the central portion of the space 6X in the longitudinal direction X, and the space 6Y in the width direction Y is the shortest, and the intersection region The thickness of the central portion of the 6XY is the thinnest among the low basis weights 42. According to this configuration, it is possible to absorb the moisture existing between the absorbent article 1D and the skin of the wearer through the intersection region 6XY, and the wearer is less likely to feel stuffy.

The absorber (absorbent core) of the fourth aspect of the invention can be produced by the same method as the method for producing the absorbent body (absorbent core) of the first invention. The absorbent body 4D (absorbent core 40D) of the fourth aspect of the invention can be produced in the same manner as the absorbent body 4A (absorbent core 40A) of the first invention, using the apparatus for producing an absorbent body shown in FIG. In the method for producing the absorbent body 4D (absorbent core 40D) according to the fourth aspect of the invention, a description will be given of a method for producing the absorbent body 4A (absorbent core 40A) according to the first aspect of the invention.

The material forming in the absorbent article 1D will be described.

As the front sheet 2, various materials previously used in the art can be used without particular limitation. As the front sheet 2, for example, a liquid permeable sheet such as a non-woven fabric or an apertured film can be used.

As the material for forming the absorbent core 40D, that is, the absorbent material 45, Various materials previously used in the technical field are used without particular limitation, for example, as a fiber material, natural fibers such as wood pulp, cotton, and hemp; composite fibers containing synthetic resins such as polyethylene or polypropylene; acetate or Semi-synthetic fibers such as enamel. Further, as the absorbent material, in addition to the fibrous materials, various shapes of water-absorbent polymers such as pellets may be used.

As the back sheet 3, a moisture permeable sheet having moisture permeability can be used. Examples of the moisture-permeable sheet include a sheet having a plurality of fine pores and having a high water vapor permeability. For example, an inorganic powder such as calcium carbonate or barium sulfate, nylon or polyphenylene is preferably used. A sheet having fine pores and having high water vapor permeability obtained by uniaxially or biaxially stretching a polyethylene film obtained by kneading an organic polymer having no compatibility such as ethylene. Specifically, a polyethylene film having a basis weight of 20 to 50 g/m ² containing 30 to 60% by weight of calcium carbonate having an average particle diameter of 0.5 to 1.0 μm is used in MD (Machine Direction, machine direction/longitudinal direction). A moisture permeable film having a basis weight of 13 to 28 g/m ^{2 which} is obtained by stretching twice in the direction. As the moisture permeable sheet, a water-repellent non-woven fabric or a composite sheet of the above-mentioned sheet and the water-repellent non-woven fabric may be used.

In the case where the absorbent article 1D is used for menstrual sanitary napkins, it is necessary to have sufficient air permeability for rapidly exposing moisture existing between the wearer's skin and the surface of the menstrual sanitary napkin, and has a menstrual blood The moisture permeability of the moisture permeable sheet used in the back sheet 3 is preferably 0.5 g/100 cm ^{2 from} the viewpoint of sufficient water pressure resistance of the fine pores oozing through the air. Above hr, more preferably 1.0 g/100 cm ² . Above hr, and preferably, it is 3.0 g/100 cm ² . Below hr, more preferably 2.0 g/100 cm ² . Below hr, more specifically, it is preferably 0.5 to 3.0 g/100 cm ² . Hr, more preferably 1.0~2.0 g/100 cm ² . Hr.

In the case where the absorbent article 1D is used in a disposable diaper, it is necessary to rapidly evaporate a large amount of moisture generated from the urine from the inside of the disposable diaper, and it is difficult to wet the back sheet 3 due to urine and menstrual blood. Moreover, it is easily repelled by the back sheet 3, so that the moisture permeability of the moisture permeable sheet used in the back sheet 3 is higher than that of the back sheet 3, which is easy to exhibit sufficient water pressure resistance. Good for 0.7 g/100 cm ² . Above hr, more preferably 1.2 g/100 cm ² . Above hr, and more preferably, it is 4.0 g/100 cm ² . Below hr, more preferably 3.0 g/100 cm ² . Below hr, more specifically, it is preferably 1.2 to 3.0 g/100 cm ² . Hr, more preferably 0.7~4.0 g/100 cm ² . Hr.

The effect of the use of the absorbent article 1D of the embodiment of the present invention (fourth invention) will be described.

As shown in Fig. 27, the absorbent body 4D included in the absorbent article 1D includes an integrally formed high basis weight portion 41 (convex portion) and a low basis weight portion 42 (low basis weight portion 42X, 42Y) (recessed portion), and a low base. The heavy portion 42 (the low basis weight portions 42X and 42Y) is biased against the front sheet 2 side, and has a concavo-convex structure on the back sheet 3 side of the absorber 4D. In this manner, since the high basis weight portion 41 and the low basis weight portion 42 (low basis weight portions 42X and 42Y) are integrally molded, when the absorbent article 1D is used, the body fluid is liable to be biased against the low base of the front sheet 2 side. The heavy portion 42 (low basis weight portions 42X, 42Y) is moved to the high basis weight portion 41, and further, the absorber 4D of the absorbent article 1D is provided with the high basis weight portion 41 and the low basis weight portion 42 (low basis weight portion 42X). 42Y), the length of the lower side L5 of the back sheet 3 side is longer than the length of the upper side L4 of the front sheet 2 side, that is, the surface area of the side of the back sheet 3 of the absorber 4D is more positive. The surface area on the side of the sheet 2 is large, so that the amount of vapor emission on the side of the back sheet 3 is likely to increase. Again, due to absorption The recessed portion (low basis weight portion 42 (low basis weight portion 42X)) in the uneven structure on the back sheet 3 side of the body 4D and the space 6X formed by the moisture-permeable back sheet 3 continuously extend in the longitudinal direction X. Therefore, the space 6X is used as a passage, and the moisture in the dress during use is easily diffused. Therefore, according to the absorbent article 1D, the humidity in the dress at the time of use can be effectively reduced, and the moist feeling can be lowered, thereby giving a comfortable wearing feeling.

In particular, in the absorbent article 1D, since the high basis weight portion 41 (convex) is formed at a higher density than the low basis weight portion 42 (42X, 42Y) (recessed portion), the body fluid is easier to use when the absorbent article 1D is used. The low basis weight portion 42 (low basis weight portions 42X, 42Y) that is biased against the front sheet 2 side moves toward the high basis weight portion 41. Since the absorption capacity of the high basis weight portion 41 is relatively higher than that of the low basis weight portion 42 and is high in density, the lower basis weight portion 42 absorbs liquid more quickly. Therefore, since the low basis weight portion 42 is more difficult to absorb the liquid than the high basis weight portion 41, it is difficult to expand, and even after the absorber 4D absorbs the liquid in a relatively large amount, the spaces 6X and 6Y adjacent to the low basis weight portion are not Will disappear. In particular, in the absorbent article 1D, since the space 6Y formed by the concave portion (the low basis weight portion 42 (low basis weight portion 42Y)) and the moisture-permeable back sheet 3 also continuously extends in the width direction Y, The moisture moves in a space 6Y which is shorter in the movement path, so that the moisture in the package is more likely to diffuse from both side edges of the product during use.

Further, as shown in Fig. 29 (a), the absorbent body 4D included in the absorbent article 1D has front side concave portions 43X and 43Y corresponding to the concave portions (low basis weight portions 42X and 42Y) (recess portions) of the uneven structure. Therefore, the skin abutting surface side and the non-skin abutting surface side are easily bent in any direction, and it is easy to generate more complicated deformation. Therefore, the absorbent article 1D follows the complex body curve of the wearer Flexibly deformed, thus providing the wearer with an excellent sense of wear and improved suitability, as well as providing excellent leak resistance.

The absorbent article of the invention (fourth invention) is not limited to the above embodiment.

For example, in the above-described embodiment, in the absorbent core 40D of the absorbent body 4D, as shown in Figs. 26 and 28, the high basis weight portion 41 is disposed at substantially equal intervals in the longitudinal direction X and the width direction Y. However, if the space 6X formed by the concave portion (low basis weight portion 42 (low basis weight portion 42X)) and the moisture-permeable back sheet 3 in the uneven structure continuously extends in the longitudinal direction X, the high basis weight portion 41 can also be configured in a zigzag shape. In other words, a plurality of high basis weight portions 41 are arranged at a predetermined interval in the longitudinal direction X to form a high basis weight portion row, and a plurality of the high basis weight portions are arranged at a predetermined interval in the width direction Y. In the case, the distance between the high basis weights 41 in the high basis weight rows adjacent to each other may also deviate. In other words, the high basis weight portion 41 may be disposed such that when the high basis weight portion 41 in the specific high basis weight portion row is projected in the direction orthogonal to the high basis weight portion row (width direction Y), It does not coincide with the projected image of the adjacent high basis weight 41.

The parts included in only one embodiment described above can be used as appropriate in each of the inventions (the first to fourth inventions) or in the respective inventions. Regarding the above embodiment, the following note (absorbent article) is further disclosed.

[1] An absorbent article comprising a front sheet disposed on a skin contact surface side, a back sheet disposed on a non-skin contact surface side, and an elongated body between the two sheets. An absorbent article; and the above absorbent system comprises an absorbent core comprising an absorbent material The absorbent core comprises a relatively high basis weight portion of the absorbent material and a relatively low basis weight portion of the absorbent material, wherein the high basis weight portion and the low basis weight portion are respectively The absorbent article is formed alternately in the longitudinal direction and the width direction; and the absorbent article is formed with a groove in which the front sheet and the absorbent core are integrally recessed, the groove being at least in the longitudinal direction or Two of the high basis weight portions arranged in the width direction and one of the low basis weight portions sandwiched by the two high basis weight portions are connected to each other; and the bottom wall portion dividing the groove is located in the above-mentioned absorbent The center of the thickness direction of the core body is closer to the non-skin contact surface side.

[2] The absorbent article according to the above [1], wherein the high basis weight portion and the low basis weight portion are different in density in the vicinity of the groove.

[3] The absorbent article according to the above [1] or [2] wherein the above-mentioned groove is formed in such a manner as to be on both sides in the longitudinal direction of the absorbent article in the opposing portion of the excretion portion of the absorbent article The portion includes a longitudinally elongated shape that is convex outward toward the width direction of the absorbent article in a plan view.

[4] The absorbent article according to any one of [1] to [3] wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in a plan view.

[5] The absorbent article according to any one of the above [1], wherein the low basis weight portion is formed to include a linear portion extending in a width direction of the absorbent article in a plan view, The groove is formed to include a shape of a horizontally long curved shape that is convex outward in the longitudinal direction of the absorbent article in plan view.

[6] The absorbent article according to any one of [1] to [5] wherein the high basis weight portion is thicker than the low basis weight portion, and the absorbent core body has the high basis weight portion. The uneven structure of the low base weight is raised.

[7] The absorbent article according to any one of the above [1], wherein the low basis weight portion is biased in a thickness direction of the absorbent core when viewed in a cross section of the absorbent core. Rely on the skin abutting side.

[8] The absorbent article according to any one of the above [1], wherein the skin contact surface of the absorbent core is flat and has no unevenness except for a portion where the groove is formed.

[9] The absorbent article according to any one of the above [1], wherein the low basis weight portion is biased in a thickness direction of the absorbent core when viewed in a cross section of the absorbent core. Relying on the non-skin abutting side.

[10] The absorbent article according to any one of [1] to [6], wherein the non-skin abutting surface of the absorbent core is flat without unevenness.

[11] An absorbent article comprising: a front sheet disposed on a skin contact surface side; a back sheet disposed on a non-skin contact surface side; and an elongated body interposed between the sheets An absorbent article; and wherein the absorbent system comprises an absorbent core comprising an absorbent material, the absorbent core comprising a relatively high basis weight of the absorbent material, and a relatively low amount of the absorbent material a base portion, wherein the high basis weight portion and the low basis weight portion are alternately formed in a specific direction; wherein the absorbent sheet is formed with a groove in which the front surface sheet and the absorbent core body are integrally recessed; The groove is divided by a bottom wall portion and a side wall portion that is erected from the bottom wall portion, and Formed at least with two of the high basis weight portions arranged in a specific direction and one of the low basis weight portions sandwiched by the two high basis weight portions; and the side wall formed in the low basis weight portion A portion of the portion is formed with a crack that penetrates the low basis weight portion in the thickness direction.

[12] The absorbent article according to the above [11], wherein the low basis weight portion is biased to the skin contact surface side in the thickness direction of the absorbent core when viewed in a cross section of the absorbent core.

[13] An absorbent article comprising a front sheet disposed on a skin contact surface side, a back sheet disposed on a non-skin contact surface side, and an elongated body between the two sheets. An absorbent article comprising: an absorbent core comprising an absorbent material comprising a relatively high weight portion of the absorbent material and a high basis weight portion adjacent to the absorbent core a low basis weight portion having a relatively low absorptive material, the low basis weight portion being biased against the skin abutting surface side in a thickness direction of the absorbent core; the absorbent article having the above-mentioned front sheet and the absorbent core a groove integrally recessed and extending in a longitudinal direction of the absorbent article, the groove being formed across the high basis weight portion and the low basis weight portion, and in the groove, along the length of the groove The shallow groove portion having a relatively shallow depression and the deep groove portion having a relatively deep depression are alternately formed in the direction; the shallow groove portion has a length in the longitudinal direction of the groove which is longer than the deep groove portion.

[14] The absorbent article according to the above [12] or [13] wherein the skin abutting surface of the absorbent core is flat and not concave except for the formation portion of the groove. Convex.

[15] The absorbent article according to any one of [11] to [14] wherein, in the vicinity of the groove, the high basis weight portion and the low basis weight portion have different densities.

[16] The absorbent article according to any one of the above [11], wherein the groove is formed in a manner of the length of the absorbent article in the opposing portion of the excretion portion of the absorbent article. Both sides of the direction include a longitudinally convex shape that is convex outward in the width direction of the absorbent article in plan view.

[17] The absorbent article according to any one of the above [11], wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in a plan view.

[18] The absorbent article according to any one of the above [11], wherein the low basis weight portion is formed to include a linear portion extending in a width direction of the absorbent article in a plan view, The groove is formed to include a shape of a horizontally long curved shape that is convex outward in the longitudinal direction of the absorbent article in plan view.

[19] An absorbent article comprising a front sheet disposed on a skin contact surface side, a back sheet disposed on a non-skin contact surface side, and an elongated body between the two sheets. An absorbent article; wherein the back sheet has moisture permeability; the absorber includes a high basis weight having a relatively high basis weight, and a low basis weight adjacent to the high basis weight and having a relatively low basis weight. The high basis weight portion and the low basis weight portion are integrally formed, and the convex portion as the high basis weight portion and the concave portion as the low basis weight portion are alternately arranged on the back sheet side of the absorber. Concave-convex structure, and the low basis weight is biased against the above-mentioned absorber On the front sheet side, the concave portion is recessed toward the front sheet side, the convex portion is convex toward the back sheet side, and a space formed by the concave portion and the back sheet is continuously extended at least in the longitudinal direction.

[20] The absorbent article according to any one of [11] to [19] wherein the high basis weight portion is thicker than the low basis weight portion, and the absorbent core body has the high basis weight portion. The uneven structure of the low base weight is raised.

[21] An absorbent article comprising a front sheet disposed on a skin contact surface side, a back sheet disposed on a non-skin contact surface side, and an elongated body between the two sheets. An absorbent article; and the absorbent body comprises a high basis weight portion having a relatively high basis weight, and a low basis weight portion adjacent to the high basis weight portion and having a relatively low basis weight, the low basis weight portion being in the absorbent article The absorbent article is disposed on the side of the skin contact surface; the absorbent article includes a groove in which the front sheet and the absorbent body are integrally recessed and extends in the longitudinal direction of the absorbent article, the groove spanning the above The high base weight portion is formed with the low base portion, and in the groove, a shallow groove portion which is relatively shallowly recessed and a deep groove portion which is relatively deeply recessed are alternately formed along the longitudinal direction of the groove. The shallow groove portion is longer than the deep groove in the length direction of the groove.

[22] The absorbent article according to the above [21], wherein in the low basis weight portion, the basis weight of the side wall portion dividing the groove is lower than the portion located farther from the groove than the side wall portion .

[23] The absorbent article according to the above [21] or [22] wherein the above absorbent body The low basis weight portion is closer to the front sheet than the high basis weight portion at a portion of the non-skin contact surface corresponding to the groove.

[24] The absorbent article according to any one of [21] to [23] wherein the high basis weight portion has a higher density than the low basis weight portion.

[25] The absorbent article according to any one of [21] to [24] wherein the shallow groove portion has a length in the longitudinal direction of the absorbent article shorter than the high basis weight portion.

[26] The absorbent article according to any one of the above [21], wherein the absorbent body comprises the linear low-weight portion extending in a longitudinal direction of the absorbent article, and the groove comprises The length direction is different from the portion of the linear low basis weight.

[27] An absorbent article comprising: a front sheet disposed on a skin contact surface side; a back sheet disposed on a non-skin contact surface side; and an elongated body interposed between the sheets An absorbent article; and wherein the absorbent system comprises an absorbent core comprising an absorbent material, the absorbent core comprising a relatively high basis weight of the absorbent material, and a relatively low amount of the absorbent material a base portion, wherein the high basis weight portion and the low basis weight portion are alternately formed in a specific direction; and in the absorbent article, the front surface sheet and the absorbent core body are integrally recessed The groove is defined by the bottom wall portion and the side wall portion erected from the bottom wall portion, and is sandwiched by at least two of the high basis weight portions arranged in a specific direction and by the two high basis weight portions. One of the low basis weight portions is connected to each other; and a portion of the low basis weight portion constituting the side wall portion is formed thick The crack of the low basis weight is penetrated in the direction of the dimension.

[28] The absorbent article according to the above [27], wherein the high basis weight portion and the low basis weight portion are different in density in the vicinity of the groove.

[29] The absorbent article according to the above [27] or [28] wherein the above-mentioned groove is formed in such a manner as to be on both sides in the longitudinal direction of the absorbent article in the opposing portion of the excretion portion of the absorbent article The portion includes a longitudinally elongated shape that is convex outward toward the width direction of the absorbent article in a plan view.

[30] The absorbent article according to the above [29], wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in a plan view.

The absorbent article according to any one of the above aspects, wherein the low basis weight portion is formed to include a linear portion extending in a width direction of the absorbent article in a plan view, The groove is formed to include a shape of a horizontally long curved shape that is convex outward in the longitudinal direction of the absorbent article in plan view.

[32] The absorbent article according to any one of the above [27], wherein the groove comprises a shallow groove portion which is relatively shallowly depressed, and a deep groove portion which is relatively deeply depressed, the deep groove portion At least a portion of the overlap with the low basis weight portion in a plan view.

[33] The absorbent article according to [32], wherein the deep groove portion is located at a central portion in a width direction of the groove, and the shallow groove portion is located outward in the width direction of the deep groove portion.

[34] An absorbent article comprising a front sheet disposed on a skin-facing side, a back sheet disposed on a non-facing side, and two An elongated absorbent article of a longitudinally long absorbent body between sheets; and said back sheet has moisture permeability; said absorbent body comprising a relatively high basis weight having a relatively high basis weight and adjacent to said high basis weight portion And the low basis weight portion having a relatively low basis weight, the high basis weight portion and the low basis weight portion are integrally formed, and a convex portion as the high basis weight portion is formed on the back sheet side of the absorber The concave portion of the low basis weight portion is alternately arranged in a concave-convex structure, and the low basis weight portion is biased against the front surface side of the absorbent body, the concave portion is recessed toward the front sheet side, and the convex portion is directed to the back sheet The material side is convex; the space formed by the concave portion and the back surface sheet continuously extends at least in the longitudinal direction.

[35] The absorbent article according to [34], wherein the concave portion is disposed to surround the convex portion, and the space continuously extends in the longitudinal direction and the width direction.

[36] The absorbent article according to the above [34], wherein the absorbent system has a direction corresponding to the concave portion of the uneven structure on the back sheet side on the side of the front sheet of the absorbent body. The front side concave portion of the back sheet side is recessed; and the depth of the concave portion is deeper than the depth of the front side concave portion.

[37] The absorbent article according to any one of [34] to [36] wherein the high basis weight portion has a higher density than the low basis weight portion.

[38] The absorbent article according to any one of [35], wherein the space extends continuously in the longitudinal direction and the width direction, and the space extending in the longitudinal direction extends in the width direction. Within the intersection of space The low basis weight portion is the thinnest in the central portion of the intersection region.

[39] The absorbent article according to any one of [35] to [38] wherein the high basis weight portion forming the convex portion is formed in an arc shape in a plan view.

Example

Hereinafter, the present invention (the first invention and the second invention) will be more specifically described by way of examples, but the invention is not limited to the examples.

[Example 1A]

A menstrual sanitary napkin having the same constitution as that of the sanitary napkin 1A shown in Figs. 1 and 2 was produced and used as a sample of Example 1A. As the front sheet, a front sheet having a two-layer structure (described later in detail) was used, and as the back sheet, a film made of a non-permeable polyethylene having a basis weight of 30 g/m ² was used as the side sheet. An air through nonwoven having a basis weight of 20 g/m ² was used, and as a coated core material covering the absorbent core, an absorbent paper having a basis weight of 16 g/m ² was used. As the absorbent core, those manufactured by the above method are used. The absorbent core used in Example 1 is a block-type absorbent core having the same constitution (concave-convex structure) as that of the absorbent core 40A shown in Fig. 3, and the weight ratio is the former: the latter =4:1 as a absorbent material, a bleached softwood kraft pulp (NBKP (Needle Bleached Kraft Pulp), a fibrous material) and a particulate absorbent polymer having a mixed fiber type absorbent core, an absorbent core The basis weight of the whole pulp is 200 g/m ² , the basis weight of the water-absorbing polymer is 50 g/m ² , the basis weight of the high basis weight is 300 g/m ² , and the thickness of the high basis weight is 2.0 mm. The basis weight of the low basis weight is 140 g/m ² , the thickness of the low basis weight is 0.8 mm, the total length in the longitudinal direction is 200 mm, and the total length in the width direction is 75 mm. Further, regarding the high basis weight portion, the length L2 in the longitudinal direction (see FIG. 3(a)) is 20 mm, and the length L3 in the width direction (see FIG. 3(a)) is 10 mm. Further, 18 of the high basis weight area is formed every 50 cm ² . Further, the groove width L5 (see Fig. 3(b)) is 2 mm, and the groove depth L6 (see Fig. 5) is 0.5 mm.

The top sheet having the two-layer structure used in Example 1A includes a layer on the skin contact surface side and a layer on the non-skin contact surface side, and the separately manufactured upper layer and the lower layer are integrally formed. The above upper layer is manufactured in the following manner. Namely, first, as the non-heat-shrinkable fused fiber, a core-sheath type composite fiber manufactured by Daiwa Textile Co., Ltd. (trade name NBF-SH, core: polyethylene terephthalate, sheath: polyethylene, core / Sheath weight ratio = 5/5, denier 2.2 dtex, fiber length 51 mm), the fused fiber was defibrated using a card to form a mesh, and then the web was heat treated by hot air method (120 ° C A hot air non-woven fabric having a basis weight of 20 g/m ² was obtained, and the hot air non-woven fabric was set as the above upper layer. Further, the above lower layer is produced in the following manner. In other words, the core-shrinkable fiber (the core-sheath type composite fiber in which the ethylene-propylene random copolymer is used as the core component and the polypropylene as the sheath component) exhibits heat shrinkability, and the fineness is 2.2 dtex, Dahe Textile Co., Ltd. The production was carried out, and the crimping start temperature was 90 ° C. As a raw material, a net having a basis weight of 20 g/m ^{2 was} produced using a carding machine in the same manner as above, and the web was set as the lower layer.

Then, the upper layer and the lower layer are separately produced in this manner to obtain a polymer, and the polymer is subjected to hot embossing by a hot embossing roll device including a combination of an engraving roll and a smooth roll, thereby making the two layers partially The ground joint is integrated to obtain a non-woven fabric having an embossed portion (recessed portion). At this time, the engraving roller is brought into contact with the lower layer, and the embossing process is performed from the side of the lower layer. The engraving roll was set at 175 ° C and the smooth roll system was set at 125 ° C. The embossing pattern of the engraving roll is a so-called thousand bird grid pattern, and each embossing point constituting the pattern is circular (embossed area is 0.047 cm ² ) and the distance (pitch) of the embossing point along the mechanical direction is 7 Mm, the distance (pitch) of the embossing point along the transverse direction is 7 mm, and the distance between the embossing points in the direction of inclination of 45° is 5 mm. The embossed area ratio at this time point was 7.2%. Next, the obtained non-woven fabric was subjected to heat treatment (hot air processing) for 1 to 3 minutes in a heat drier heated to 130 °C. The heat-extensible fiber (the upper non-heat-shrinkable fused fiber) included in the nonwoven fabric is stretched in a portion other than the embossed portion (concave portion) by the heat treatment of the nonwoven fabric, and at this time, a part of the fiber is The embossed portion is fixed, whereby the extended portion of the elongated fiber is lost in the direction of the non-woven fabric and moves in the thickness direction of the non-woven fabric. As a result, a convex portion is formed in each of a plurality of regions surrounded by the embossed portion of the pattern of the bird's-eye pattern in each of the non-woven skin contact surface and the non-skin contact surface. Thus, a front sheet comprising a non-woven fabric having a two-layer structure having projections on both sides was obtained. In the front sheet (non-woven fabric having a two-layer structure), the fiber density at the protrusion of the skin contact surface was 0.04 g/cm ³ , and the fiber density at the protrusion of the non-skin contact surface was 0.10 g/cm. ^3. The fiber density of the embossed portion is 0.70 g/cm ³ . Further, the ratio (q ₂ /q ₁ ) of the total area (q ₂ ) of the embossed portion to the surface area (q ₁ ) of the front sheet was 0.29.

[Example 2A]

A menstrual sanitary napkin was produced in the same manner as in Example 1A except that the absorbent core described below was used as the absorbent core, and this was designated as Example 2A.

The absorbent core used in Example 2A: the position of the lower basis weight in the thickness direction of the absorbent core is opposite to that of the absorbent core used in Example 1A, and is a non-skin abutting surface. Side absorbent core (block type absorbent core). The absorbent core was constructed in the same manner as the absorbent core used in Example 1A except for the above aspects, including the dimensions.

[Comparative Example 1A]

A menstrual sanitary napkin was produced in the same manner as in Example 1A except that the absorbent core described below was used as the absorbent core, and this was designated as Comparative Example 1A.

The absorbent core used in Comparative Example 1A is an absorbent portion of a plurality of specific basis weights (part of the absorbent core used in Example 1A corresponding to a high basis weight portion) to the absorbent core. Each of the longitudinal direction and the width direction is independent of each other with a predetermined interval therebetween, and the absorbent material is not present between the two adjacent absorbent portions to form a space portion (that is, there is no equivalent to that used in the embodiment 1A). An absorbent core (block-type absorbent core) of a portion of the low basis weight of the absorbent core. The absorbent core was constructed in the same manner as the absorbent core used in Example 1A except for the above aspects, including the dimensions.

[Comparative Example 2A]

A menstrual sanitary napkin was produced in the same manner as in Example 1A except that the absorbent core described below was used as the absorbent core, and this was designated as Comparative Example 2A.

The absorbent core used in Comparative Example 2A is a skin abutting surface which does not have a concave-convex structure and which is distributed on the entire core body with a uniform basis weight and does not include a low basis weight portion and a high basis weight portion. Non-skin abutting surface is generally flat Absorbent core (flat absorbent core). The absorbent core was constructed in the same manner as the absorbent core used in Example 1A except for the above aspects, including the dimensions.

[Evaluation A]

With respect to each of the samples (menstrual sanitary napkins) of Examples 1A to 2A and Comparative Examples 1A to 2A, dynamic maximum absorption, flexibility, and gas permeability were evaluated by the following methods. The results of these are shown in Table 1 below.

<Evaluation method of dynamic maximum absorption amount>

The menstrual sanitary napkin is fixed to the menstrual shorts, and the menstrual shorts are worn on the dynamic model of the human body. The dynamic model starts the walking action, and after 1 minute of the walking movement, as the first liquid infusion operation, 2 g of horse blood is injected into the menstrual sanitary napkin from the liquid excretion point of the dynamic model, and then the first time Three minutes after the completion of the liquid injection operation, as a second liquid injection operation, 3 g of horse blood was injected from the liquid excretion point of the dynamic model into the menstrual sanitary napkin, and 3 minutes after the end of the second liquid injection operation, As the third liquid injection operation, 2 g of horse blood was injected from the liquid excretion point of the dynamic model to the menstrual sanitary napkin. The liquid injection operation after the third time was carried out by injecting 2 g of horse blood from the liquid excretion point of the dynamic model to the menstrual sanitary napkin 3 minutes after the end of the last liquid injection operation. This liquid injection operation is repeated until the liquid (horse blood) oozes out from the side flap portion of the menstrual sanitary napkin, and the total amount of the liquid injected by the liquid injection operation before the liquid oozing is set as the dynamic maximum absorption amount. The larger the value of the dynamic maximum absorption amount, the more excellent the leakage prevention of menstrual blood, and the higher the evaluation.

<Evaluation method of softness>

The bending rigidity of the absorbent core in the menstrual sanitary napkin was evaluated in accordance with JIS L-1096 (Common Fabric Test Method). As the evaluation device, a Handle-O-Meter (Model: HOM-3) manufactured by Daiei Scientific Seiki Co., Ltd. was used. The slit width of the rigid flexible measuring device was set to 40 mm. More specifically, the absorbent body (when the coated core material is coated with the absorbent core) is taken out from the menstrual sanitary napkin, and the absorbent body taken out from the longitudinal flexible measuring device is used (the total length in the longitudinal direction is 200 mm, The entire length of the width direction was 75 mm. The portion of the front end portion of 100 mm was bent in the longitudinal direction and the width direction, and the load value at this time was measured. The smaller the load value, the more excellent the flexibility, and the higher the evaluation.

<Evaluation method of gas permeability>

The laminate of the front sheet and the absorbent body (the coated core material is coated with the absorbent core) is taken out from the menstrual sanitary napkin, and an elliptical injection port (length 5 cm, width 2.2 cm, area 11) is used. For the acrylic plate of cm ² ), 6 g of blood coagulation was injected from the injection port to the central portion of the side of the front sheet in the laminate, and left for 1 minute. Thereafter, the front sheet was removed from the laminate, and the remaining absorbent was used as an evaluation sample to evaluate the gas permeability. The evaluation of the gas permeability is based on the "paper and paperboard - air permeability test method - Gurley test machine method" specified in JIS P8117 (1998), and the Gurley test machine type B (trade name "GURLEY DENSOMETER", Kumagai The manufacturing of the machine industry (stock) is carried out. Specifically, as shown in FIG. 11 , the evaluation sample 90 (when the coated core material is coated with the absorbent core) is used to make the skin contact surface of the evaluation sample 90 and the acrylic on the air injection side. The plate 91 was sandwiched between two acrylic plates 91 and 92 of a square of 50 mm in length and width, and was placed on a Gurley testing machine. One of the acrylic plates 91 has a square through hole 93 penetrating the longitudinal direction of the acrylic plate 91 in the thickness direction at the center portion thereof. On the other hand, the other acrylic plate 92 does not have a through hole. Further, the weight of one of the acrylic sheets 91 was 9.7 g, and the size of the evaluation sample 90 was set to exceed the size of the acrylic sheets 91 and 92. Then, the time required for the passage of 300 ml of air (the time required for the injection, in seconds) was measured by the method described in JIS P8117 (1998), and the gas permeation rate (ml/sec) was calculated from the measured value. The larger the value of the gas permeable speed, the more excellent the gas permeability, and the higher the evaluation.

As is clear from the results shown in Table 1, in Examples 1A and 2A, the values of the dynamic maximum absorption amount were larger than those of Comparative Examples 1A and 2A, and were excellent in leakage prevention of menstrual blood, and the load value at the time of bending was small. It is also excellent in softness. From this result, it is revealed that, as described above, a groove of a specific structure is formed in a specific pattern in an absorbent core (block-type absorbent core) having a low basis weight and a high basis weight formed in a specific pattern. This is effective in obtaining an absorbent article which is excellent in absorption and diffusibility of the excretory fluid and which is difficult for the wearer to produce an uncomfortable feeling due to wetting. Further, from the comparison between Examples 1A and 2A and Comparative Example 1A and Comparative Example 2A, the following revelation was made: the region having the uneven structure The block type absorbent core is superior in air permeability to a flat absorbent core having no uneven structure, and is excellent in air exchange effect between the skin of the sanitary napkin wearer and the sanitary napkin.

[Example 1B]

A menstrual sanitary napkin having the same constitution as that of the sanitary napkin 1B shown in Figs. 12 and 13 was produced and used as a sample of Example 1B. As the front sheet, a front sheet having a two-layer structure was used, and as the back sheet, a film made of a non-permeable polyethylene having a basis weight of 30 g/m ² was used, and as a side sheet, a basis weight of 20 g/m was used. ² hot air non-woven fabric, as a coated core material covering the absorbent core, an absorbent paper having a basis weight of 16 g/m ² was used. As the absorbent core, those manufactured by the above method are used. The absorbent core used in Example 1B has the same constitution (concave-convex structure) as that of the absorbent core 40B shown in Fig. 14, and is included in the weight ratio of the former: the latter = 4:1. a mixed fiber-type absorbent core of a bleached softwood kraft pulp (NBKP, fiber material) and a particulate water-absorbing polymer of a material, the basis weight of the absorbent core as a whole is 200 g/m ² , The water-absorbent polymer has a basis weight of 50 g/m ² , a high basis weight of 300 g/m ² , a high basis weight of 2.0 mm, and a low basis weight of 140 g/m ^{2 .} The low basis weight has a thickness of 0.8 mm, the length in the longitudinal direction is 200 mm, and the length in the width direction is 75 mm. Further, regarding the high basis weight portion, the length L2 in the longitudinal direction (see FIG. 14(a)) is 20 mm, and the length L3 in the width direction (see FIG. 14(a)) is 10 mm. Further, 18 of the high basis weight area is formed every 50 cm ² . Further, the groove width L5 (see Fig. 14 (b)) is 2 mm, and the groove depth L6 (see Fig. 16) is 0.5 mm. Further, the length L8 (see FIG. 18(a)) in the longitudinal direction of the groove of the shallow groove portion is 3.4 mm, and the length L9 (see FIG. 18(a)) in the longitudinal direction of the groove of the deep groove portion is 1.0 mm.

[Comparative Example 1B]

The same as in the first embodiment except that the length L8 in the longitudinal direction of the groove of the shallow groove portion and the length L9 in the longitudinal direction of the groove of the deep groove portion were respectively set to 1.2 mm as the absorbent core. The menstrual sanitary napkin was produced in the same manner as Comparative Example 1B.

The absorbent core used in Comparative Example 1B is a skin abutting surface which does not have a concave-convex structure and which is uniformly distributed in the core body without a low basis weight and a high basis weight. Absorbent core that is not flat on the non-skin contact surface. The absorbent core was constructed in the same manner as the absorbent core used in Example 1B except for the above aspects.

[Comparative Example 2B]

A menstrual sanitary napkin was produced in the same manner as in Example 1B except that the same absorbent core as used in Comparative Example 1B was used as the absorbent core, and this was designated as Comparative Example 2B.

[Evaluation B]

With respect to each sample (menstrual sanitary napkin) of Example 1B and Comparative Examples 1B to 2B, the dynamic maximum absorption amount and flexibility were evaluated in accordance with the above method. The results of these are shown in Table 2 below.

As is clear from the results shown in Table 2, in Example 1B, the value of the dynamic maximum absorption amount was larger than that of Comparative Examples 1B and 2B, and it was excellent in prevention of leakage of menstrual blood, and the load value at the time of bending was small and soft. Excellent also. From this result, it is revealed that, as described above, a groove of a specific configuration is formed in a specific pattern in an absorbent core in which a low basis weight and a high basis weight are formed in a specific pattern, thereby obtaining a rapid absorption of the excretion liquid. Further, it is effective in dispersing, eliminating discomfort caused by wetting by the wearer, and having an anti-leakage groove, but having an appropriate degree of flexibility and excellent suitability.

1A‧‧‧Sanitary cotton

1B‧‧‧Sanitary cotton

1C‧‧‧Sanitary cotton

1D‧‧‧Absorbables

2‧‧‧Front sheet

2a‧‧‧ Skin contact surface of the front sheet 2

3‧‧‧Back sheet

3b‧‧‧ Non-skin abutment of back sheet 3

4A‧‧‧ absorber

4B‧‧‧ absorber

4C‧‧‧ absorber

4D‧‧‧ absorber

4a‧‧‧Skin contact surface

4b‧‧‧Non-skin abutment

5‧‧‧Side sheet

5‧‧‧peripheral seal

6‧‧‧Flanking

6X‧‧‧ space

6Y‧‧‧ Space

6XY‧‧‧Intersection of space 6X and space 6Y

7‧‧‧ slot

7X‧‧‧Longitudinal slot

7Y1‧‧‧ transverse slot

7Y2‧‧‧ transverse slot

10‧‧‧Absorbable ontology

11‧‧‧Department of the Department of Excretion

12‧‧‧ front section

13‧‧‧ Rear

40A‧‧‧Absorbent core

40B‧‧‧Absorbent core

40B'‧‧‧Absorbable core

40C‧‧‧Absorbable core

40D‧‧‧Absorbable core

41‧‧‧High base weight (convex)

42‧‧‧Low basis weight (non-convex or concave)

42X‧‧‧Low basis weight

42Y‧‧‧Low basis weight

43‧‧‧Front side recess

43X‧‧‧Front side recess

43Y‧‧‧Front side recess

45‧‧‧Absorbable materials

46‧‧‧ Deposits

46a‧‧‧Partitioning part

46b‧‧‧ Division of regional counterparts

47‧‧‧1st package of chip

48‧‧‧2nd package of chip

49‧‧‧ Absorber precursor

50‧‧‧Rotating cylinder

51‧‧‧Cylinder recess

52‧‧‧Date the bottom of area 54

53‧‧‧Parts

54‧‧‧Division area

56‧‧‧ Space

57‧‧‧ Space

58‧‧‧ Space

60‧‧‧ catheter

61‧‧‧ downstream end of duct 60

65‧‧‧vacuum box

70‧‧‧Transfer roller

71‧‧‧ bottom wall

71‧‧‧ Space

72‧‧‧ Side wall

73‧‧‧ shallow groove

74‧‧‧ Deep groove department

75‧‧‧Net belt

78‧‧‧ crack

80‧‧‧Vacuum conveyor

81‧‧‧ drive roller

82‧‧‧ driven roller

83‧‧‧ breathable belt

84‧‧‧vacuum box

90‧‧‧ Pressurizing mechanism

90‧‧‧ Evaluation sample

91‧‧‧ Roll

91‧‧‧Acrylic board

92‧‧‧roll

92‧‧‧Acrylic board

93‧‧‧through holes

A‧‧‧ parts

B‧‧‧ parts

C‧‧‧ parts

CL‧‧‧ center line

D‧‧‧ parts

D1‧‧‧Deep depth of the front side recesses 43X, 43Y

Depth of d2‧‧‧ recess (low basis weight 42X, 42Y)

E‧‧‧ parts

L1‧‧‧Low base weight 42 width

Length of length direction X of L2‧‧‧ high base weight 41

Length of width direction Y of L3‧‧‧ high base weight 41

L4‧‧‧ top side of the front side of the sheet 2

L5‧‧‧Under the back side of the sheet 3

L5‧‧‧ slot 7 width

L6‧‧‧ Depth of slot 7

L7‧‧‧ Length of crack 78 along the length of slot 7

L8‧‧‧ Length of crack 78 along the width of groove 7

L8‧‧‧ Length of the groove in the shallow groove portion 73

Length of the length of the groove of the L9‧‧ deep groove 74

L9‧‧‧ Length of the width direction of the shallow groove portion 73

Length of width direction of L10‧‧ deep groove 74

L41‧‧‧ distance

L42‧‧‧ distance

R1‧‧ direction

R2‧‧‧ direction

T‧‧‧ thickness direction

The center of the thickness direction of the Tc‧‧·absorbent core

W‧‧‧Drainage

X‧‧‧ length direction

Y‧‧‧Width direction

Fig. 1 is a perspective view showing a part of the menstrual sanitary napkin of an embodiment of the absorbent article of the present invention (first invention), which is omitted from the skin contact surface side.

Fig. 2 is a cross-sectional view schematically showing a cross section taken along line I-I of Fig. 1.

Fig. 3(a) is a plan view showing the absorbent core used in the menstrual sanitary napkin of Fig. 1 from the skin abutting side, and Fig. 3(b) is a part of Fig. 3(a) surrounded by a circle. Part of it) is a plan view enlarged.

Fig. 4 is a cross-sectional view schematically showing a cross section taken along line II-II of Fig. 3(b).

Fig. 5 is a cross-sectional view schematically showing a cross section taken along line III-III of Fig. 3(b).

Fig. 6 is a cross-sectional view schematically showing a cross section taken along line IV-IV of Fig. 3(b).

Figure 7 is a manufacturing method of the absorbent body (absorbent core) shown in Figure 3. A schematic cross-sectional view of a manufacturing apparatus and a manufacturing apparatus used in the embodiment.

Fig. 8 is a schematic cross-sectional view showing a width direction of a portion (recess) on the outer peripheral side in the rotary cylinder shown in Fig. 7.

Fig. 9 is a schematic cross-sectional view showing a state in which an absorbent material is deposited in a concave portion of the rotary cylinder shown in Fig. 8.

Figure 10 is an explanatory view of a compression step of the deposit.

Fig. 11 is an explanatory view showing a method of evaluating the gas permeability by the Gurley tester method.

Fig. 12 is a perspective view showing a part of the menstrual sanitary napkin of an embodiment of the absorbent article of the present invention (second invention).

Fig. 13 is a cross-sectional view schematically showing a cross section taken along line I-I of Fig. 12.

Fig. 14 (a) is a plan view showing the absorbent core used in the menstrual sanitary napkin of Fig. 12 from the skin abutting side, and Fig. 14 (b) is a part of Fig. 14 (a) surrounded by a circle. Part of it) is a plan view enlarged.

Fig. 15 is a cross-sectional view schematically showing a cross section taken along line II-II of Fig. 14(b).

Fig. 16 is a cross-sectional view schematically showing a cross section taken along line III-III of Fig. 14(b).

Fig. 17 is a cross-sectional view schematically showing a cross section taken along line IV-IV of Fig. 14(b).

Figure 18 (a) is a plan view showing a part of the absorbent core shown in Figure 14 (a) in an enlarged manner (corresponding to Figure 14 (b)), Figure 18 (b) and Figure 18 (c) respectively A part of the absorptive core body and the groove outside the range of the present invention (second invention) is enlarged and shown.

Fig. 19 is a view showing the suction of the present invention (third invention) from the skin contact surface side. A portion of the menstrual sanitary napkin of one embodiment of the disposable article lacks a perspective view.

Fig. 20 is a cross-sectional view schematically showing a cross section taken along line I-I of Fig. 19.

Figure 21 (a) is a plan view showing the absorbent core used in the menstrual sanitary napkin of Figure 19 from the skin abutting side, and Figure 21 (b) is a part of Figure 21 (a) surrounded by a circle. Part of it) is a plan view enlarged.

Fig. 22 is a cross-sectional view schematically showing a cross section taken along line II-II of Fig. 21 (b).

Fig. 23 is a cross-sectional view schematically showing a cross section taken along line III-III of Fig. 21 (b).

Fig. 24 is a cross-sectional view schematically showing a cross section taken along line IV-IV of Fig. 21(b).

Fig. 25 is a plan view schematically showing a part (the crack and its vicinity) of Fig. 21(b) in an enlarged manner.

Fig. 26 is a partially omitted perspective view showing one embodiment of the absorbent article of the present invention (fourth invention) from the side facing the skin.

Fig. 27 is a cross-sectional view schematically showing a cross section taken along the line Y1-Y1 of Fig. 26.

Fig. 28 is a plan view showing the absorbent core used in the absorbent article shown in Fig. 26 from the skin-facing side.

Fig. 29 (a) is a cross-sectional view schematically showing a Y2-Y2 line cross section of Fig. 28, and Fig. 29 (b) is a cross-sectional view schematically showing a Y3-Y3 line cross section of Fig. 28.

4a‧‧‧Skin contact surface

7‧‧‧ slot

7X‧‧‧Longitudinal slot

7Y1‧‧‧ transverse slot

7Y2‧‧‧ transverse slot

11‧‧‧Department of the Department of Excretion

12‧‧‧ front section

13‧‧‧ Rear

40A‧‧‧Absorbent core

41‧‧‧High base

42‧‧‧Low basis weight

42X‧‧‧Low basis weight

42Y‧‧‧Low basis weight

A‧‧‧ parts

B‧‧‧ parts

C‧‧‧ parts

D‧‧‧ parts

E‧‧‧ parts

L1‧‧‧Low base weight 42 width

Length of length direction X of L2‧‧‧ high base weight 41

Length of width direction Y of L3‧‧‧ high base weight 41

L5‧‧‧ slot 7 width

W‧‧‧Drainage

X‧‧‧ length direction

Y‧‧‧Width direction

Claims (6)

An absorbent article comprising a front sheet disposed on a skin contact surface side, a back sheet disposed on a non-skin contact surface side, and an absorbent article longitudinally interposed between the sheets And the absorption system comprises an absorbent core comprising an absorbent material comprising a relatively high basis weight portion of the absorbent material and abutting the high basis weight portion and the absorbent material a relatively low basis weight portion, the low basis weight portion is biased against the skin abutting surface side in a thickness direction of the absorbent core; the absorbent article having the above-mentioned front sheet and the absorbent core integrally a groove recessed in the longitudinal direction of the absorbent article, the groove being formed across the high basis weight portion and the low basis weight portion, and in the groove, alternately along the length direction of the groove A shallow groove portion having a relatively shallow depression and a deep groove portion having a relatively deep depression; the shallow groove portion having a length in the longitudinal direction of the groove is longer than the deep groove portion. The absorbent article according to claim 1, wherein the skin contact surface of the absorbent core is flat and has no irregularities except for the portion where the groove is formed. The absorbent article of claim 1 or 2, wherein said high basis weight portion is different in density from said low basis weight portion in the vicinity of said groove. The absorbent article according to claim 1 or 2, wherein the groove is located on both sides of the absorbent portion in the longitudinal direction of the absorbent article in the opposing portion of the absorbent article, and includes the absorbent article in a plan view. It is formed in such a manner that the width direction outwardly protrudes from the longitudinal shape of the bend. The absorbent article according to claim 1 or 2, wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in a plan view. The absorbent article according to claim 1 or 2, wherein the low basis weight portion is formed to include a linear portion extending in a width direction of the absorbent article in a plan view, the groove being oriented to include the absorption in a plan view The length of the sexual article is formed by protruding outwardly from the shape of the curved transverse length.