JP2013255571A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article capable of reducing skin wetting by exhibiting a proper absorption rate even when a liquid is repeatedly supplied under pressure.SOLUTION: An absorbent article 1 has an absorbent body 20 which includes a front-side sheet 21, a back-side sheet, and an absorbent core 22 arranged between the front-side sheet 21 and the back-side sheet. In the absorbent core 22, a through-hole 230 elongated in a longitudinal direction Y is provided in the width-direction-X central part of the absorbent body, and a plurality of lateral grooves 214d elongated in the width direction X of the absorbent body from the through-hole 230 are provided. In each of the lateral grooves 214d, an absorptive layer exists at least on the skin abutting surface side of an internal space of the groove.

Description

  The present invention relates to an absorbent article such as a disposable diaper.

A technique is known in which a through hole is formed in the absorbent core of a disposable diaper having an absorbent main body including a top sheet, a back sheet, and an absorbent core to improve the absorption rate (see Patent Document 1).
However, in the disposable diaper in which the through-hole is formed in the absorbent core, when urination is repeatedly performed while the absorbent core is pressurized while wearing the diaper, the second time compared to the first time of urination. A phenomenon in which the absorption rate during subsequent urination is greatly reduced tends to occur. This decrease in the absorption rate increases the amount of liquid remaining in the surface sheet without being absorbed by the absorbent core, and makes it easier for the wearer to feel uncomfortable due to an increase in the amount of liquid adhering to the skin or induction of stuffiness.

In addition, an absorbent article using a block-like absorbent body provided with a groove-like space extending in the planar direction is known. For example, Patent Literature 2 describes an absorbent article including an absorbent body having a plurality of small absorbent portions and a base sheet positioned on the non-skin contact surface side. The adjacent small absorption parts are divided, and a recess is formed between them. According to this absorbent article, there is an advantage that the amount of absorption and retention is improved due to high liquid diffusion performance, and that a large number of small absorbent portions can be effectively used even in absorption for repeated excretion and the like.
However, even in the case where grooves are formed vertically and horizontally with a block-shaped absorbent body, the phenomenon that the absorption rate during the second and subsequent urination is greatly reduced tends to occur, and there is room for improvement in terms of improvement.

Patent Document 3 describes that in the absorbent core, a through hole formed in the upper layer of the absorbent core having a two-layer structure is communicated with a groove in the lower layer at the end of the through hole. According to this absorbent article, there is an advantage of improving the liquid absorbency by having in the lower layer a groove that communicates with the through hole of the upper layer in one direction of the longitudinal front and rear end portions of the through hole of the lower layer smaller than the upper layer. .
However, when the lower layer groove is communicated only at the end of the through hole (only the groove communicated so as to extend in the length direction of the through hole), the liquid having the energy to diffuse along the through hole However, there is a phenomenon in which the liquid concentrates on the end side and flows into the communicating groove, the liquid diffuses more than necessary in the longitudinal direction of the absorber, and induces leakage from the end side in the longitudinal direction of the absorber. Further, in Patent Document 3, since the opening made on the lower surface is smaller than the opening on the upper surface, the lower surface opening becomes narrower due to the swelling of the absorbent body and the communication portion groove becomes narrower at the second and subsequent urinations. Is difficult to obtain.

JP 2012-34715 A JP 2011-136034 A JP 2011-104021 A

  Therefore, the subject of this invention is providing the absorbent article which can eliminate the fault which the prior art mentioned above has.

  The present invention is an absorbent article having a topsheet, a backsheet, and an absorbent main body including an absorbent core disposed between the topsheet and the backsheet, wherein the absorbent core is the absorbent. It has a through hole extending in the longitudinal direction at the center in the width direction of the main body, and has a plurality of horizontal grooves extending from the through hole in the width direction of the absorbent main body, and the horizontal groove is at least the skin of the internal space of the groove An absorbent article having an absorbent layer on the abutting surface side is provided.

  According to the absorbent article of the present invention, even when the liquid is repeatedly supplied under pressure, it exhibits a good absorption rate and can reduce skin wetting.

FIG. 1 is a perspective view of a pants-type disposable diaper that is an embodiment of the absorbent article of the present invention. FIG. 2 is a plan view of a state in which the diaper shown in FIG. 1 is opened at its side seal portion and developed in a plane, as viewed from the skin contact surface side. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 4 is an exploded perspective view of the absorbent core in the absorbent main body of the diaper shown in FIG. Fig.6 (a) is a top view of the 2nd absorptive core in the absorptive core shown in FIG. 5, FIG.6 (b) and FIG.6 (c) are respectively the bb line | wire cross sections in Fig.6 (a). It is a figure and a cc line sectional view. Fig.7 (a) is a top view of the 1st absorptive core in the absorptive core shown in FIG. 5, FIG.7 (b) and FIG.7 (c) are respectively the bb line | wire cross sections in Fig.7 (a). It is a figure and a cc line sectional view. FIG. 8 is a schematic plan view showing an absorbent core according to another embodiment of the present invention. FIG. 9 is a schematic diagram illustrating an example of a manufacturing apparatus for the first absorbent core and the second absorbent core in the absorbent body illustrated in FIG. 5. FIG. 10 is a schematic cross-sectional view along the width direction of a part (concave portion) on the outer peripheral surface side of the rotating drum shown in FIG. 9. FIG. 11 is a schematic cross-sectional view showing a state where an absorbent material is deposited in the concave portion of the rotating drum shown in FIG. FIG. 12 is an exploded perspective view of another form of absorbent core that can be used in the present invention, and corresponds to FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 is a perspective view of a pants-type disposable diaper that is an embodiment of the absorbent article of the present invention. FIG. 2 is a plan view in which the diaper shown in FIG. 1 is opened at its side seal portion and developed in a plane as viewed from the surface sheet side. FIG. 3 shows a cross-sectional view along the width direction of the diaper of FIG.

  The diaper 10 shown in FIGS. 1-3 is what is called a pants-type diaper. The diaper 10 has a longitudinal direction Y and a width direction X orthogonal thereto. The diaper 10 includes an absorbent main body 20 and an exterior body 30 located on the non-skin contact surface side of the absorbent main body 20. The diaper 10 has a crotch portion C located in a central region in the longitudinal direction Y, and a ventral side portion A and a back side portion B extending from the crotch portion C forward and backward in the longitudinal direction. The ventral portion A is arranged on the wearer's ventral side when the diaper 10 is worn. The back part B is arranged on the wearer's back side when the diaper 10 is worn. The crotch part C is arranged on the wearer's crotch when the diaper 10 is worn.

  In the following description, the “non-skin contact surface side” refers to the side (surface) that is disposed on the opposite side of the skin side of the wearer when worn among the front and back sides (surfaces) of each member such as the absorbent main body 20. ). The “skin contact surface side” is the side (surface) that is disposed on the skin side of the wearer when wearing, out of the front and back sides (surfaces) of each member. Moreover, regarding the longitudinal direction of the diaper 10, the abdominal side A side is also referred to as “front side”, and the back side A side is also referred to as “rear side”.

  The absorbent main body 20 has a vertically long rectangular shape, and an adhesive such as a hot-melt adhesive so that its longitudinal direction coincides with the longitudinal direction Y of the diaper 10 and extends from the ventral side A to the back side B. It joins to the width direction center part of the exterior body 30 by various well-known joining methods, such as. Moreover, it is preferable that the absorbent core 22 and the core wrap sheet 24, and between the core wrap sheet 24 and the back sheet 23 are also bonded via an adhesive. The adhesive that joins the members may be applied to the entire surface without any gap in the plane direction, or may be partially applied with various patterns such as a spiral pattern, a stripe pattern, and a dot pattern.

  The exterior body 30 is configured such that both side edges of the portion located on the ventral side A and both side edges of the portion located on the back side B are connected to each other by known joining means such as heat seal, high frequency seal, and ultrasonic seal. It is joined. Accordingly, a pair of side seal portions S is formed on the diaper 10. Moreover, the waist opening part 11 and a pair of leg opening parts 12 and 12 are formed in the diaper 10 by the joining, and the exterior body 30 becomes a pants-type solid shape.

  The absorptive main body 20 includes a top sheet 21, a back sheet 23, and an absorptive core 22 interposed between both sheets. The top sheet 21 is made of a liquid-permeable sheet and faces the wearer's skin when the diaper 10 is worn. The back sheet 23 is made of a liquid-impermeable or water-repellent sheet and faces the exterior body 30.

  As the surface sheet 21 and the back surface sheet 23, those similar to those conventionally used in the technical field can be used without particular limitation. For example, as the top sheet 21, a liquid-permeable nonwoven fabric or a perforated film can be used. As the back sheet 23, a water-repellent nonwoven fabric with high water pressure resistance such as a liquid-impermeable film made of a synthetic resin or a spunbond-meltblown-spunbond laminated nonwoven fabric can be used. When the back sheet 23 is liquid impermeable, the back sheet may have water vapor permeability. From the viewpoint of leakage prevention and breathability, the back sheet 23 is preferably a liquid impermeable film made of a synthetic resin having water vapor permeability.

  As shown in FIG. 3, the outer package 30 includes an inner layer sheet 31 and an outer layer sheet 32, and elastic members of respective parts fixed between the two sheets. The elastic member of each part will be described later. The outer edge of the exterior body 30 forms the outline of the unfolded diaper 10. The inner layer sheet 31 and the outer layer sheet 32 have the same shape. However, the outer layer sheet 32 has an extending portion that extends outward in the longitudinal direction from the front end edge and the rear end edge of the inner layer sheet 31. The extending portion is folded back from the front end edge and the rear end edge of the inner layer sheet 31 toward the skin contact surface side, and covers the front end area and the rear end area in the longitudinal direction of the absorbent main body 20. The positions of the front edge and the rear edge of the inner layer sheet 31 coincide with the position of the waist opening edge W. The inner layer sheet 31 and the outer layer sheet 32 are preferably composed of the same or different breathable sheets, for example, non-woven fabrics manufactured by various methods.

  As shown in FIG. 2, the exterior body 30 has a waist located between the waist opening edge W and the position of the longitudinal end of the absorbent core 22 on both the back side A and the abdominal side B. In the region U, a plurality of waist elastic members 33 extending in the width direction X of the diaper 10 are arranged in an extended state. The waist region U is arranged around the wearer's waist when worn. In addition, a leg elastic member 34 is disposed along the opening edge L in an extended state on the leg opening edge L of the exterior body 30.

  The exterior body 30 has a plurality of waistline elastic members 35 extending in the width direction of the diaper 10 on the waistline part D located between the waist region U and the crotch part C on both the back side part A and the stomach side part B. Are arranged in an extended state. One or a plurality of waistline elastic members 35 are arranged, one end of which is located in the vicinity of the side portion of the exterior body 30, for example, in the vicinity of the side seal portion S, and the other end is in the center region in the width direction of the diaper 10. Terminate before reaching. Therefore, a region where the waistline elastic member 35 does not exhibit elastic stretching force is formed in the central region of the waistline portion D in the diaper width direction X.

  As shown in FIG. 4, the absorptive main body 20 includes a top sheet 21, a back sheet 23, and an absorbent body disposed between both sheets. In the absorbent body, the entire absorbent core 22 is covered with a liquid-permeable core wrap sheet 24. The core wrap sheet prevents leakage of the core forming material. For example, a thin paper or a water-permeable nonwoven fabric is used.

  As shown in FIGS. 3 to 5, the absorbent core 22 includes a first absorbent core 210 and a second absorbent core 220. The first absorbent core 210 is disposed on the non-skin contact surface side, and the second absorbent core 220 is disposed on the skin contact surface side. The first absorbent core 210 and the second absorbent core 220 are entirely covered with a liquid-permeable core wrap sheet 24. The core wrap sheet 24 prevents leakage of the core forming material. For example, a thin paper or a water-permeable nonwoven fabric is used.

  FIG. 6A shows a plan view of the second absorbent core 220. 6B and 6C are a cross-sectional view taken along the line bb and a cross-sectional view taken along the line cc in FIG. 6A, respectively. The second absorbent core 220 has a vertically long shape extending in the same direction as the longitudinal direction of the diaper 1 in a plan view, and is symmetric with respect to the longitudinal center line CL. The second absorbent core 220 has a front end edge 221a and a rear end edge 221b. The front end edge 221a is located closer to the ventral portion A and extends linearly in the width direction. The rear end edge 221b is located closer to the back side B and extends linearly in the width direction. The front edge 221a and the rear edge 221b are substantially parallel. Further, the rear end edge 221b is longer than the front end edge 221a.

  Furthermore, the 2nd absorptive core 220 has a pair of side edge 222 extended in a longitudinal direction. The shape of the side edge 222 is symmetric with respect to the longitudinal center line CL. The side edge 222 is a curved line connecting the first straight line portion 222a located near the front end edge 221a, the second straight line portion 222b located near the rear end edge 221b, and the first straight line portion 222a and the second straight line portion 222b. Part 222c. The pair of first linear portions 222 a are parallel to each other, and the extending direction thereof coincides with the longitudinal direction of the second absorbent core 220. Similarly, the pair of second linear portions 222b are also parallel to each other, and the extending direction thereof coincides with the longitudinal direction of the second absorbent core 220. The distance between the pair of second straight portions 222b is smaller than the distance between the pair of first straight portions 222a. In addition, the distance between the pair of second linear portions 222b substantially matches the length of the rear end edge 221b. On the other hand, the distance between the pair of first straight portions 222a substantially matches the length of the front end edge 221a. The extending length of the first straight portion 222a is smaller than the extending length of the second straight portion 222b. A curved portion 222c that connects the first straight portion 222a and the second straight portion 222b has a slightly curved curve toward the inside in the width direction of the second absorbent core 220. The two straight portions 222b are smoothly connected.

  As shown in FIGS. 6B and 6C, the second absorbent core 220 has a first surface 223a and a second surface 223b. The 1st surface 223a is a skin contact surface, and has faced the surface sheet 21 or the intermediate sheet (not shown) side used as needed. The second surface 223b is the non-skin contact surface side and faces the first absorbent core 210 side.

  The second absorbent core 220 has a relatively high basis weight and is adjacent to the high basis weight portion 224a having a convex shape protruding toward the non-skin contact surface side, and the high basis weight portion 224a, and is relatively And a low basis weight portion 224b that is recessed from the non-skin contact surface side toward the skin contact surface side. As for the 2nd absorptive core 220, the high basic weight part 224a and the low basic weight part 224b are integrally molded. As for the 2nd absorptive core 220, the non-skin contact surface side has an uneven | corrugated shape, and the skin contact surface side is flat.

  As shown in FIG. 6A, a plurality of low basis weight portions 224 b extend in parallel with the longitudinal direction of the second absorbent core 220. A plurality of the low basis weight portions 224 b also extend in the width direction of the second absorbent core 220. As a result, the low basis weight part 224b has an orthogonal lattice shape extending in the longitudinal direction and the width direction of the second absorbent core 220. And the 2nd absorptive core 220 has the high basic weight part 224a located in the grating | lattice formed of the low basic weight part 224b. Therefore, each high basic weight part 224a is divided by the low basic weight part 224b, and is independent independently. The shape of each high basic weight part 224a is substantially the same, it is rectangular in plan view, and the length in the longitudinal direction is larger than the length in the width direction.

  As described above, the low basis weight portion 224b has a shape recessed from the non-skin contact surface side toward the skin contact surface side. Due to the presence of the low basis weight portion 224b, the second absorbent core 220 has a longitudinal groove 224c extending in the longitudinal direction of the absorbent core 22 and an absorbent core at the lower portion of the second absorbent core 220 as shown in FIG. A lateral groove 224d extending in the width direction of 22 is formed. In the plan view of the second absorbent core 220, the lateral grooves 224d located on both sides of the central through-hole 225 have one end in the width direction X of the absorbent core 22 at the center, as shown in FIGS. It opens to the inner wall surface of the through hole 225, and the other end communicates with the vertical groove 224c. Further, the lateral groove 224d formed in the lower part of the second absorbent core 220 has an absorbent layer that can absorb liquid on the skin contact surface side of the internal space of the lateral groove 224d. . Further, on the non-skin contact surface side of the internal space of the lateral groove 224d formed in the lower part of the second absorbent core 220, as shown in FIG. 3, the flat skin contact surface of the first absorbent core 210 is provided. The lateral groove 224d has an absorption layer on the skin contact surface side and the non-skin contact surface side of the internal space. Therefore, the internal space of the horizontal groove 224d communicates between the central through hole 225 and the vertical groove 224c in a tunnel shape. The width of the low basis weight portion 224b extending in the longitudinal direction of the second absorbent core 220 and the width of the low basis weight portion 224b extending in the width direction of the second absorbent core 220 may be the same or different. May be.

As for the basic weight of the low basic weight part 224b, the ratio with respect to the basic weight of the high basic weight part 224a is preferably 1%, and more preferably 3%. The upper limit is preferably 80%, more preferably 70%. The lower limit of the basis weight of the high basis weight portion 224a itself is preferably 80 g / m ² , and more preferably 150 g / m ² . The upper limit is preferably 500 g / m ² , more preferably 400 g / m ² . Regarding the low basis weight part 224b, the lower limit value of the basis weight is preferably 10 g / m ² , and more preferably 50 g / m ² . The upper limit is preferably 300 g / m ² , more preferably 200 g / m ² . The basis weight is measured as follows.
The absorbent core 22 is cut using a single blade razor manufactured by Feather Corporation along the boundary line between the high basis weight portion 224a and the low basis weight portion 224b. The small piece of the high basic weight part 224a obtained by cutting is measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point). The basis weight of the small piece is calculated by dividing the obtained weight by the area of the small piece of the high basis weight portion 224a. Let the average of the basic weight of 5 pieces be the basic weight of the high basic weight part 224a.
Next, along the boundary line extending to the high basis weight portion 224a and the low basis weight portion 224b, a small piece of the low basis weight portion is cut out using a single blade razor manufactured by Feather Corporation. The weight of the obtained small piece is measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point). The basis weight of the small piece is calculated by dividing the obtained weight by the area of the small piece of the low basis weight portion 224b. Let the average of the basic weight of 5 pieces be the basic weight of the low basic weight part 224b.

The high basis weight part 224a not only has a larger basis weight than the low basis weight part 224b, but also has a larger thickness. The ratio of the thickness of the low basis weight part 224b to the thickness of the high basis weight part 224a is preferably 2%, more preferably 3%. The upper limit is preferably 80%, more preferably 70%. The lower limit of the thickness of the high basis weight portion 224a itself is preferably 1.5 mm, and more preferably 2.5 mm. The upper limit is preferably 8 mm, more preferably 6 mm. Regarding the low basis weight part 224b, the lower limit of the thickness is preferably 0.5 mm, and more preferably 0.7 mm. The upper limit is preferably 5 mm, more preferably 4 mm. The thickness is measured as follows.
A sample is cut into a predetermined size, the measurement site is pressurized at 5 kPa for 10 minutes, and measurement is performed by the following method immediately after dewetting. The number of measurement points is 3 or more per sheet, and the thickness is obtained by averaging two diaper samples (6 or more measurement points). For example, the diaper 10 is cut in the longitudinal direction (Y direction) or the lateral direction (X direction) shown in FIG. 2 with a feather razor manufactured by Feather, and the cross section of the cut sample is measured. When it is difficult to measure with the naked eye, the section of the cut sample may be observed and measured at a magnification of 20 to 100 times using, for example, a microscope (VHX-1000 manufactured by KEYENCE).

  The block region is disposed from the crotch C to the ventral side A of the second absorbent core 220. The block region has a crotch lower high basis weight portion group 227C provided at a position corresponding to the crotch portion C and a ventral side high basis weight portion group 227A provided at a position corresponding to the abdominal side portion A. doing. Each high basic weight part group is connected. In each high basic weight part group, the number of the high basic weight parts 224a arrange | positioned along the width direction differs. Specifically, the number of high basis weight portions 214a in the ventral portion high basis weight portion group 227A is larger than the number of high basis weight portions 224a in the crotch lower high basis weight portion group 227C. For example, as shown in FIG. 6A, in the abdominal portion high basis weight portion group 227A, the number of high basis weight portions 214a arranged along the width direction is six or four, In the crotch lower high basis weight part group 217C, the number of the high basis weight parts 224a arranged along the width direction is two. As described above, the width of the block region changes according to the width of the second absorbent core 220, and the block region has a larger width as the width of the second absorbent core 220 is larger. In this embodiment, since the dimension of the high basic weight part 224a is the same in each high basic weight part group, the number of arrangement | positioning of the high basic weight part 224a in the abdominal part high basic weight part group 227A is the crotch height. More than the number of arrangement of the high basis weight parts 224a in the basis weight part group 227C, that is, the width of the block area in the ventral part A is larger than the width of the block area in the crotch part C. Means.

  In the block region, a vertically long central through hole 225 is formed at a position on the longitudinal center line CL of the second absorbent core 220 along the longitudinal center line CL. The central through hole 225 passes through the entire thickness direction of the second absorbent core 220. The central through hole 225 is formed at the position of the second straight part 222b and the curved part 222c. The central through hole 225 is not formed at the position of the first straight portion 222a. The central through-hole 225 has one end in the longitudinal direction that does not reach the front end edge 221a and terminates at a position closer to the rear end edge 221b than the front end edge 221a. A pair of high basis weight portions 224a are located on both sides of the central through hole 225 in the width direction.

  A non-blocking region 226 is disposed on the outer side in the longitudinal direction and the outer side in the width direction of the block region in the second absorbent core 220. That is, the 2nd absorptive core 220 is comprised from the block area | region which consists of the high basic weight part 224a and the low basic weight part 224b, and the non-blocking area | region 226. The non-blocking area 226 surrounds the entire area of the block area. The block area and the non-block area 226 are partitioned by a low basis weight portion 224b located on the outermost periphery of the block area. In the non-blocking region 226, the thickness and basis weight at an arbitrary position are constant.

  As shown in FIGS. 6B and 6C, in the present embodiment, the thickness of the non-block region 226 is substantially the same as the thickness of the high basis weight portion 224a of the block region. However, the relationship between the thickness of the non-blocking region 226 and the thickness of the high basis weight portion 224a is not limited to this, and the thickness of the non-blocking region 226 may be larger, and conversely the thickness of the high basis weight portion 224a. May be large. Specifically, the lower limit of the thickness of the non-block region 226 is preferably 1.5 mm, and more preferably 2.5 mm. The upper limit is preferably 8 mm, more preferably 6 mm. The method for measuring the thickness is as described above.

The basis weight of the non-block region 226 may be the same as or different from the basis weight of the high basis weight portion 224a of the block region. Further, the basis weight of the low basis weight portion 224b of the block region may be the same or different. Specifically, the lower limit of the basis weight of the non-block region 226 is preferably 80 g / m ² , and more preferably 150 g / m ² . The upper limit is preferably 500 g / m ² , more preferably 400 g / m ² . The method for measuring the basis weight is as described above.

  As described above, the high basis weight portion 224a and the low basis weight portion 224b are integrally formed. Moreover, the block area | region which consists of the high basic weight part 224a and the low basic weight part 224b, and the non-block area | region 226 located in the outer periphery are also integrally molded. “Integrally molded” means that these parts are integrated without being separated from each other without using a bonding means such as an adhesive or heat fusion, and are integrally formed from the same material. Means that When these parts are integrally molded, the body fluid has continuity that can move smoothly. A method for manufacturing the absorbent core having such a structure will be described later.

  The above is description of the 2nd absorptive core 220 in the absorptive core 22, About the structure of the 1st absorptive core 210 arrange | positioned at the non-skin contact surface side of this 2nd absorptive core 220, it is the following. It is as follows.

  As shown in FIG. 5, the first absorbent core 210 extends outward from the peripheral edge of the second absorbent core 220, and its outer shape is larger than that of the second absorbent core 220. Therefore, in a state where the second absorbent core 220 is disposed on the first absorbent core 210 to form the absorbent core 22, the absorbent core 22 is a peak protruding toward the skin contact surface side. The shape of the mold.

  FIG. 7A shows a plan view of the first absorbent core 210. 7B and 7C are a cross-sectional view taken along the line bb and a cross-sectional view taken along the line cc in FIG. 7A, respectively. The first absorbent core 210 has a vertically long shape extending in the same direction as the longitudinal direction of the diaper 1 in a plan view, and is symmetric with respect to the longitudinal center line CL. The first absorbent core 210 has a front end edge 211a and a rear end edge 211b. The front end edge 211a is located closer to the ventral side A and extends linearly in the width direction. The rear end edge 211b is positioned closer to the back side B and extends linearly in the width direction. The front edge 211a and the rear edge 211b are substantially parallel. Further, the front end edge 211a and the rear end edge 211b have substantially the same length. Furthermore, the 1st absorptive core 210 has a pair of side edge 212 extended in a longitudinal direction. The pair of side edges 212 are substantially parallel and extend linearly in the longitudinal direction. Thus, the 1st absorptive core 210 is carrying out the planar view and has the shape of the rectangle which has a long side in a longitudinal direction.

  As shown in FIGS. 7B and 7C, the first absorbent core 210 has a first surface 213a and a second surface 213b. The 1st surface 213a is a skin contact surface, and has faced the surface sheet 21 or the intermediate sheet (not shown) side used as needed. The second surface 213b is the non-skin contact surface side and faces the back sheet 23 side.

  The first absorbent core 210 has a relatively high basis weight and has a convex shape protruding toward the non-skin contact surface side, and is adjacent to the high basis weight portion 214a and is relatively And a low basis weight portion 214b that is recessed from the non-skin contact surface side toward the skin contact surface side. As for the 1st absorptive core 210, the high basic weight part 214a and the low basic weight part 214b are integrally molded. The first absorbent core 210 has a concavo-convex structure on the non-skin contact surface side, and the skin contact surface side is flat.

  As shown in FIG. 7A, a plurality of low basis weight portions 214 b extend in parallel to the longitudinal direction of the first absorbent core 210. A plurality of the low basis weight portions 214 b also extend in the width direction of the first absorbent core 210. As a result, the low basis weight portion 214b has an orthogonal lattice shape extending in the longitudinal direction and the width direction of the first absorbent core 210. And as for the 1st absorptive core 210, the high basic weight part 214a is located in the grating | lattice formed of the low basic weight part 214b. Therefore, each high basic weight part 214a is divided by the low basic weight part 214b, and is independently independent. The shapes of the respective high basis weight portions 214a are substantially the same, are rectangular in plan view, and the length in the longitudinal direction is larger than the length in the width direction.

  As described above, the low basis weight portion 214b has a shape recessed from the non-skin contact surface side toward the skin contact surface side. Due to the presence of the low basis weight portion 214b, the first absorbent core 210 has a longitudinal groove 214c extending in the longitudinal direction of the absorbent core 22 and an absorbent core at the bottom of the first absorbent core 210 as shown in FIG. A lateral groove 214d extending in the width direction of 22 is formed. In a plan view of the first absorbent core 210, the lateral grooves 214d located on both sides of the central through-hole 215 have one end in the width direction X of the absorbent core 22 at the center as shown in FIGS. 3 and 7A. It opens to the inner wall surface of the through-hole 215, and the other end communicates with the vertical groove 214c. Further, the lateral groove 214d formed in the lower part of the first absorbent core 210 has an absorbent layer that can absorb liquid on the skin contact surface side of the inner space of the lateral groove 214d. Yes. Further, as shown in FIG. 3, the back sheet 23 exists on the non-skin contact surface side of the inner space of the lateral groove 214d formed in the lower part of the first absorbent core 210, and the lateral groove 214d The absorbent layer and the back sheet 23 are present on the skin contact surface side and the non-skin contact surface side of the internal space. Therefore, the inner space of the horizontal groove 214d communicates between the central through hole 215 and the vertical groove 214c in a tunnel shape. Further, the width of the low basis weight portion 214b extending in the longitudinal direction of the first absorbent core 210 and the width of the low basis weight portion 214b extending in the width direction of the first absorbent core 210 may be the same, or May be different.

The ratio of the basis weight of the low basis weight portion 214b to the basis weight of the high basis weight portion 214a is such that the lower limit is preferably 1%, more preferably 3%, and the upper limit is preferably 80. %, More preferably 70%. The lower limit of the basis weight of the high basis weight portion 214a itself is preferably 80 g / m ² , and more preferably 150 g / m ² . The upper limit is preferably 500 g / m ² , more preferably 400 g / m ² . Regarding the low basis weight portion 214b, the lower limit value of the basis weight is preferably 10 g / m ² , and more preferably 50 g / m ² . The upper limit is preferably 300 g / m ² , more preferably 200 g / m ² . The method for measuring the basis weight is as described above.

  The high basis weight part 214a not only has a larger basis weight than the low basis weight part 214b, but also has a larger thickness. The ratio of the thickness of the low basis weight portion 214b to the thickness of the high basis weight portion 214a is preferably a lower limit of 2%, and more preferably 3%. The upper limit is preferably 80%, more preferably 70%. The lower limit of the thickness of the high basis weight portion 214a itself is preferably 1.5 mm, and more preferably 2.5 mm. The upper limit is preferably 8 mm, more preferably 6 mm. Regarding the low basis weight portion 214b, the lower limit of the thickness is preferably 0.5 mm, and more preferably 0.7 mm. The upper limit is preferably 5 mm, more preferably 4 mm. The method for measuring the thickness is as described above.

  The block region is disposed from the abdominal side A to the back side B of the first absorbent core 210. The block region includes a ventral portion high basis weight portion group 217A provided at a position corresponding to the ventral portion A, and a dorsal portion high basis weight portion group 217B provided at a position corresponding to the dorsal portion B. And a crotch part high basis weight part group 217C provided at a position corresponding to the crotch part C. Each high basic weight part group is connected. In each high basic weight part group, the number of the high basic weight parts 214a arrange | positioned along the width direction differs. Specifically, the number of the high basis weight portions 214a in the abdominal portion high basis weight portion group 217A and the back side high basis weight portion group 217B is the number of the high basis weight portions 214a in the crotch high basis weight portion group 217C. More than the number of arrangements. For example, as shown to Fig.7 (a), in the abdominal part high basic weight part group 217A, the number of the high basic weight parts 214a arrange | positioned along the width direction is eight, and a back side high basic weight part In the group 217B, there are eight or four, whereas in the crotch high basis weight part group 217C, the number of high basis weight parts 214a arranged along the width direction is two. In this embodiment, since the dimension of the high basic weight part 214a is the same in each high basic weight part group, the high basic weight part in the abdominal part high basic weight part group 217A and the back side high basic weight part group 217B. The number of the arrangement of 214a is larger than the number of the arrangement of the high basis weight portion 214a in the crotch lower high basis weight portion group 217C, that is, the ventral side portion A and the back side than the width of the block region in the crotch portion C. This means that the width of the block area in part B is larger. By adopting such a configuration, the liquid can be efficiently diffused from the crotch part C corresponding to the urination part to the abdominal part A or the dorsal part B. The absorption area of the ventral part A or the back part B with a distance can be used effectively.

  In the block region, a vertically long central through hole 215a is formed at a position on the longitudinal center line CL of the first absorbent core 210 along the longitudinal center line CL. The central through hole 215a penetrates the entire thickness direction of the first absorbent core 210. The central through hole 215a is formed at the position where the crotch lower high basis weight portion group 217C is formed. The central through-hole 215a is not formed at the position of the ventral side high basis weight part group 217A and the back side high basis weight part group 217B. A pair of high basis weight portions 214a forming part of the crotch lower high basis weight portion group 217C are located on both sides in the width direction of the central through hole 215a. The length and width of the central through hole 215a are substantially the same as the length and width of the central through hole 225 formed in the second absorbent core 220 described above.

  A non-block region 216 is disposed outside the block region in the first absorbent core 210 in the width direction. That is, the 1st absorptive core 210 is comprised from the block area | region which consists of the high basic weight part 214a and the low basic weight part 214b, and the non-blocking area | region 216. FIG. The non-blocking region 216 is arranged over the entire region in the longitudinal direction at positions on both the left and right sides of the block region. The block area and the non-block area 216 are partitioned by a low basis weight portion 214b located on the outermost periphery of the block area. In the non-blocking region 216, the thickness and basis weight at any position are constant.

  As shown in FIGS. 7B and 7C, in this embodiment, the thickness of the non-block region 216 is substantially the same as the thickness of the high basis weight portion 214a of the block region. However, the relationship between the thickness of the non-blocking region 216 and the thickness of the high basis weight portion 214a is not limited to this, and the thickness of the non-blocking region 216 may be larger, and conversely the thickness of the high basis weight portion 214a. May be large. Specifically, the lower limit of the thickness of the non-blocking region 216 is preferably 1.5 mm, and more preferably 2.5 mm. The upper limit is preferably 8 mm, more preferably 6 mm. The method for measuring the thickness is as described above.

The basis weight of the non-block region 216 may be the same as or different from the basis weight of the high basis weight portion 214a of the block region. Further, the basis weight of the low basis weight portion 214b of the block region may be the same or different. Specifically, the lower limit of the basis weight of the non-block region 216 is preferably 80 g / m ² , and more preferably 150 g / m ² . The upper limit is preferably 500 g / m ² , more preferably 400 g / m ² . The method for measuring the basis weight is as described above.

  As for the 1st absorptive core 210, the high basic weight part 214a and the low basic weight part 214b of a block area | region are integrally molded. Moreover, the block area | region which consists of the high basic weight part 214a and the low basic weight part 214b, and the non-block area | region 216 located in the outer periphery are also integrally molded.

  A side opening 215 b extending in the longitudinal direction of the first absorbent core 210 is formed in the non-blocking region 216 a located on the outer side in the width direction of the blocking region. The side opening 215 b penetrates the entire thickness direction of the first absorbent core 210. The side opening 215b is formed on the outer side in the width direction of the formation position of the crotch lower high basis weight portion group 217C described above. A pair of side openings 215b are formed at positions symmetrical with respect to the longitudinal center line CL. The side opening 215b is symmetrical with respect to the longitudinal center line CL. The side opening 215b has a flat and substantially trapezoidal shape that extends linearly in the longitudinal direction and has an inner side 218a and an outer side 218b that are parallel to each other. The inner side 218a is shorter than the outer side 218b. The distance between the pair of inner sides 218a is larger than the distance between the pair of first linear portions 222a in the second absorbent core 220 described above. The side opening 215b has the same length as the central through-hole 215a or is longer than that. Further, the width of the side opening 215b is approximately the same as that of the central through-hole 215a or wider.

  Both the 1st absorptive core 210 and the 2nd absorptive core 220 are comprised from the liquid absorptive material. As the liquid-absorbing material, the same materials as those conventionally used in the technical field of absorbent articles can be used. For example, a highly absorbent polymer made of defibrated pulp or a hydrogel material can be used. The composition of the liquid absorbent material in the first absorbent core 210 and the second absorbent core 220 may be the same or different.

  The absorbent core 22 is shown in FIG. 4 when the above-described second absorbent core 220 is arranged on the first absorbent core 210 having the above-described configuration to configure the absorbent core 22. As described above, the formation positions of the crotch lower high basis weight portion group 217C of the first absorbent core 210 and the crotch lower high basis weight portion group 227C of the second absorbent core 220 are matched. Moreover, the absorptive core 22 also makes the formation position of the back side high basic weight part group 217B of the 1st absorbent core 210, and the back side high basis weight part group 227B of the 2nd absorptive core 220 correspond. Further, the absorbent core 22 has the same position as the central through hole 215a formed in the first absorbent core 210 and the central through hole 225 in which the second absorbent core 220 is formed. In addition, a central through hole 230 that penetrates the entire region in the thickness direction is formed.

  As shown in FIG. 2, the absorbent core 22 configured as described above has a central through hole 230 extending in the longitudinal direction Y at the center in the width direction X of the absorbent main body 2, and the central through hole 230. Lateral grooves 214d and 224d extending in the width direction X of the absorbent main body.

According to the diaper 1 of the present embodiment, since the absorbent core 22 has the central through hole 230 extending in the longitudinal direction Y, the excreted liquid is easily diffused in the longitudinal direction of the absorbent core 22. In addition, a plurality of lateral grooves 214d and 224d extending in the width direction X from the central through hole 230 are formed in the absorbent core 22 at different positions in the longitudinal direction Y. The liquid diffused in Y diffuses in the width direction X along the lateral grooves 214d and 224d at a plurality of portions in the longitudinal direction Y.
Such good diffusibility in the longitudinal direction and the width direction is also manifested during the second and subsequent urinations when urination is repeated under the condition where the absorbent core is pressurized.
That is, as in Patent Document 1, when there are not a plurality of lateral grooves in the width direction X, the side wall of the through hole of the liquid absorbent core and the core in the vicinity thereof absorb and hold the liquid in the first urination, As the liquid permeability deteriorates, the liquid absorption capacity at the second and subsequent urinations is greatly reduced. In particular, when a superabsorbent polymer is included, the liquid permeability is remarkably deteriorated, and the performance of liquid uptake into the absorbent core during the second and subsequent urination is large.
On the other hand, in the diaper 1 of the present embodiment, since the lateral grooves 214d and 224d suppress the deterioration of the liquid permeability in the width direction, good liquid uptake into the absorbent core even in urination after the second time. Has performance.
In particular, in a diaper, the absorber is long in the longitudinal direction and has a substantially short distance in the width direction. This is a configuration from the viewpoint of fitting to physical characteristics when wearing a diaper. Therefore, the length of the absorbent body in the width direction is substantially small, and when the diffusion is performed positively in the width direction, the structure is likely to cause leakage from the end portion in the width direction of the absorbent core. It is necessary to cause the absorbent core to quickly absorb the first and second and subsequent urinated liquids in the absorbent core and to control the diffusion force in the longitudinal direction and the width direction of the absorbent core. When the small block structure is arranged as in Patent Document 2, the diffusion direction may not be controlled. With respect to this, in the diaper 1 of the present embodiment, it is possible to ensure liquid absorption at the time of repeated urination and control in the diffusion direction in the central through hole 230 and the lateral groove extending in the width direction X.

The central through hole 230 and the lateral groove 214d communicating with the central through hole 230 and the lateral through hole 230 and the lateral groove 224d communicating with the central through hole 230 are preferably present in the crotch C, from the viewpoint of placement at the genital position when wearing the diaper, that is, the urination point. As shown in FIG. 2, when the crotch part C is divided into two equal parts in the diaper longitudinal direction and divided into abdominal crotch part Ca near the abdominal part A and a dorsal crotch part Cb near the dorsal part B. It is more preferable that it exists in ventral crotch lower part Ca.
Moreover, it is preferable that the horizontal groove 214d and the horizontal groove 224d have an inclination angle with respect to a horizontal imaginary straight line orthogonal to the longitudinal direction of the absorbent main body within 45 °, more preferably within 20 °, still more preferably 0 °. is there. An inclination angle of 0 ° with respect to the horizontal imaginary straight line means that it is parallel to the horizontal imaginary straight line.

  The lateral groove 224d formed in the lower part of the second absorbent core 220 has an absorption layer capable of absorbing liquid on the skin contact surface side and the non-skin contact surface side of the internal space of the groove 224d. By forming such a lateral groove 224d as a lateral groove communicating with the central through hole 230, it is possible to absorb liquid from the vicinity of the center in the thickness direction of the absorbent core 22 in the lateral groove, from the upper surface, the lower surface, and the side surface. Liquid absorption can be improved by absorbing liquid at a stretch. In addition, when pressure is applied to the absorbent core due to a posture change such as sitting on the skin contact surface side, skin rewetting due to liquid return (REWET) from the absorbent core can be prevented. Moreover, when there is no absorption layer on both the skin contact surface side and the non-skin contact surface side, the formed groove portion is exposed, and the deterioration of the feeling due to the swollen superabsorbent polymer being exposed to the groove portion can be reduced. it can.

  Moreover, in the diaper 1 of this embodiment, since the horizontal groove 224d is formed in the lower part of the 2nd absorptive core 220 laminated | stacked on the skin contact surface side of the 1st absorptive core 210, the 2nd absorptive core When the superabsorbent polymer is disposed in a larger amount than the first absorbent core, the lateral groove can be used as a place where the polymer of the second absorbent core can swell, and inhibition of swelling can be prevented. Absorption performance is improved in addition to the effects described in the paragraph immediately above due to the presence of an absorption layer capable of absorbing liquid on the skin contact surface side and the non-skin contact surface side of the space. Thus, by making it easy to swell the superabsorbent polymer of the second absorbent core, it is possible to increase the liquid absorbing power on the skin contact surface side, and further obtain the effect of suppressing liquid return. Moreover, the absorption performance of the urination part vicinity can be improved effectively by setting it as the structure which contains many polymers in a 2nd absorptive core.

  Further, in the diaper 1 of the present embodiment, in addition to the lateral groove 222d formed in the lower part of the second absorbent core 220, the lateral groove 214d communicating with the central through hole 230 is also provided in the lower part of the first absorbent core 210. Is formed. Therefore, the liquid absorption capability taken into the lateral groove from the central through hole is improved, and the speed at which the absorbent core takes in the urinated liquid is improved. Moreover, the place which is easy to swell a superabsorbent polymer can be arrange | positioned in a hierarchy, the deterioration of the absorptive power of the superabsorbent polymer by swelling inhibition can be suppressed, and absorption performance can be improved. Moreover, by arranging the lateral grooves in both absorbent cores, the flexibility of the absorbent core is improved, the free deformation performance of the absorbent body is improved, and the body can be fitted more.

Further, in the diaper 1 of the present embodiment, the lateral groove 214d formed in the lower part of the first absorbent core 210 has a lateral groove 224d formed in the lower part of the second absorbent core 220 and the longitudinal direction Y of the absorbent main body. However, instead of this, the lateral grooves 214d of the first absorbent core 210 and the lateral grooves 224d of the second absorbent core 220 are formed with different positions in the longitudinal direction Y. You can also. For example, in the example shown in FIG. 8, the lateral groove 214d of the first absorbent core 210 and the lateral groove 224d of the second absorbent core 220 are shifted by a half pitch.
By shifting the position of the lateral groove 214d of the first absorbent core 210 and the lateral groove 224d of the second absorbent core 220, liquid can be allowed to flow into the absorbent core from different locations (positions) with respect to the uptake by the lateral groove. Therefore, the liquid can be evenly absorbed in the absorbent core. Therefore, the local swelling of the superabsorbent polymer can be suppressed, and even if the effect of the lateral groove is suppressed due to excessive pressure due to the wearer's system, the effect can be compensated by the lateral groove in a different place.

  The width of the central through hole 215a formed in the first absorbent core 210 and the width of the central through hole 225 formed of the second absorbent core 220 are each preferably 1 mm or more, more preferably 2 mm or more, And preferably it is 25 mm or less, More preferably, it is 15 mm or less, More specifically, Preferably it is 1-25 mm, More preferably, it is 2-15 mm. The same applies to the preferred width of the central through hole when the absorbent core 22 has a single-layer structure.

The width of the lateral grooves 214d and 224d is preferably 1 mm or more, more preferably 2 mm or more, and preferably 20 mm or less, more preferably 15 mm or less, more specifically preferably 1 to 15 mm, More preferably, it is 2-10 mm.
Further, the width of one horizontal groove is smaller than the width of the central through hole, and the total width of the plurality of horizontal grooves is larger than the width of the central through hole. It is preferable from the viewpoint of diffusibility.

It is preferable that the basis weight of the second absorbent core 220 is larger than the basis weight of the first absorbent core 210 from the viewpoint of efficiently increasing the amount of absorption near the urination portion. Moreover, the amount of absorption in the vicinity of the urination portion can also be increased by increasing the amount of the superabsorbent polymer contained in the second absorbent core 220 more than that of the first absorbent core 210.
Moreover, when making the 2nd absorptive core 220 and the 1st absorptive core 210 contain a superabsorbent polymer, the fall of the liquid absorption by blocking of a superabsorbent polymer can be suppressed by the effect of a center through-hole and a transverse groove. Therefore, a large amount of the superabsorbent polymer can be blended, and the absorption amount of the absorbent core can be increased without impairing the liquid absorption performance.

  Next, the suitable manufacturing method of the 1st absorptive core 210 in the absorptive core 22 of the diaper 10 mentioned above and the 2nd absorptive core 220 is demonstrated. FIG. 9 shows an embodiment of a method for manufacturing the first absorbent core 210 and the second absorbent core 220 and a manufacturing apparatus used therefor. Hereinafter, both absorptive cores may be collectively referred to simply as “absorbent cores”. Moreover, the absorptive core as a general term of both absorptive cores is shown with the code | symbol 41. The manufacturing apparatus for the absorbent core 41 includes a rotary drum 50 that is rotationally driven in the direction of the arrow R1, and a duct that supplies a liquid-absorbing material 45 including an absorbent polymer that is a raw material of the absorbent core 41 to the outer peripheral surface of the rotary drum 50. 60, a transfer roll 70 disposed obliquely below and downstream of the rotating drum 50 and driven to rotate in the direction of arrow R2, and a vacuum disposed between the duct 60 and the transfer roll 70 in the circumferential direction of the rotating drum 50 A mesh belt 75 that is a sheet-like breathable member disposed between the box 65, the vacuum box 65 and the rotary drum 50, and between the transfer roll 70 and the rotary drum 50; And a vacuum conveyor 80 disposed below.

  As shown in FIG. 9, the rotating drum 50 has a cylindrical shape, and receives power from a prime mover such as a motor, so that members forming the outer peripheral surface rotate around a horizontal axis. A space 56 capable of depressurizing the inside is formed in a non-rotating portion inside the rotating drum 50 (on the rotating shaft side). A known exhaust device (not shown) such as an intake fan is connected to the space 56, and the interior of the space 56 can be maintained at a negative pressure by operating the exhaust device. On the other hand, piping (not shown) capable of taking in air outside the apparatus is connected to the spaces 57 and 58 on the inner side (rotating shaft side) of the rotating drum 50.

  As shown in FIG. 9, a plurality of drum recesses 51 having a shape corresponding to the shape of the absorbent core 41 to be manufactured are formed on the outer peripheral surface of the rotary drum 50 at equal intervals in the R1 direction. As shown in FIG. 11, a mesh plate 52 in which a large number of pores are formed and a metal or resin impermeable member 53 are disposed on the bottom surface of each drum recess 51. Here, the air-impermeable member 53 is provided so as to protrude on the mesh plate 52, and is arranged so as to correspond to the shape and position of the low basis weight portions 214b and 224b described above. As shown in FIG. 10, the region 54 consisting only of the mesh plate 52 partitioned by the air-impermeable member 53 arranged in this way becomes a portion corresponding to the high basis weight portions 214 a and 224 a, and A region 55 consisting only of the mesh plate 52 in the entire outer periphery of the partitioned portion is a portion corresponding to the non-blocking regions 216 and 226. Moreover, the part of the outer peripheral surface of the rotating drum 50 in which the drum recessed part 51 is not formed consists of the frame body of the rotating drum 50 which consists of metal rigid bodies, and is non-breathable.

  As shown in FIG. 9, one end side of the duct 60 covers the outer peripheral surface of the rotary drum 50 positioned on the space 56 maintained at a negative pressure, and a fiber material introduction device is provided on the other end side (not shown). Have. The fiber material introducing device includes, for example, a pulverizer that pulverizes sheet-like wood pulp into defibrated pulp and feeds the defibrated pulp (fiber material) into the duct, and introduces an absorbent polymer into the duct 60. A superabsorbent polymer introduction part is provided.

  The transfer roll 70 has a cylindrical outer peripheral portion having air permeability, and the outer peripheral portion rotates in the R2 direction upon receiving power from a prime mover such as a motor. In the non-rotating portion on the inner side (rotating shaft side) of the transfer roll 70, a space 71 that can be depressurized is formed. A known exhaust device (not shown) such as an intake fan is connected to the space 71, and the interior of the space 71 can be maintained at a negative pressure by operating the exhaust device.

  The vacuum box 65 is disposed between the downstream end 61 of the duct 60 and the transfer roll 70 in the rotation direction R1 of the rotary drum 50. The vacuum box 65 has a box-like shape and has an opening that opens in the direction of the rotating drum 50 at a portion facing the rotating drum 50. The vacuum box 65 is connected to a known exhaust device (not shown) such as an intake fan via an exhaust pipe 67, 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 belt-shaped breathable belt having a mesh connected endlessly, and is continuously guided along a plurality of free rolls and transfer rolls 70 to move along a predetermined path. The mesh belt 75 is driven by the rotation of the transfer roll 70. While the mesh belt 75 passes in front of the opening of the vacuum box 65, the mesh belt 75 is in contact with the outer peripheral surface of the rotary drum 50, and the transfer roll 70 and the rotary drum 50 are closest to each other. In the vicinity of the portion, the transfer drum 70 moves away from the outer peripheral surface of the rotating drum 50.

  The vacuum conveyor 80 includes an endless breathable belt 83 that is stretched between the drive roll 81 and the driven roll 82, and a vacuum box 84 that is disposed at a position facing the transfer roll 70 with the breathable belt 83 interposed therebetween. ing.

  Next, a method for continuously manufacturing the absorbent core using the above-described absorber manufacturing apparatus will be described. First, the exhaust device connected to each of the space 56 in the rotary drum 50 and the vacuum box 65 is operated to make negative pressure. This is because such a negative pressure in the space 56 causes an air flow in the duct 60 to convey the liquid absorbent material 45 to the outer peripheral surface of the rotary drum 50. Next, the rotating drum 50 and the transfer roll 70 are rotated, and the vacuum conveyor 80 is operated. Then, when the fiber material introduction device is operated to supply the fiber material into the duct 60 and further supply the superabsorbent polymer, the liquid absorbent material 45 rides on the air flow flowing through the duct 60 and scatters. The state is supplied toward the outer peripheral surface of the rotating drum 50.

  While the portion covered with the duct 60 is being conveyed, the liquid absorbent material (mixture of fiber material and superabsorbent polymer) 45 is sucked into the drum recess 51 of the rotary drum 50. As shown in FIG. 11, the liquid absorbing material 45 is gradually deposited on the mesh plate 52 in each region 54 and region 55 of the drum recess 51. In the deposit 46 thus obtained, a portion (a portion corresponding to the non-breathable member 53) 46 a formed by depositing the liquid-absorbing material 45 on the non-breathable member 53 is relatively deposited of the liquid-absorbent material 45. The amount of the liquid absorbing material 45 is relatively large in the other portions (corresponding to the region 54) 46b and the portion (corresponding to the region 55) 46c, and the deposit 46 as a whole has an uneven structure. To have.

  Then, when the rotary drum 50 rotates and the drum concave portion 51 comes to the position opposite to the vacuum box 65, the deposit 46 in the drum concave portion 51 is sucked to the mesh belt 75 by the suction from the vacuum box 65. It becomes. In this state, the deposit 46 in the drum recess 51 is conveyed to a position immediately before the closest portion between the transfer roll 70 and the rotary drum 50, and is sucked from the transfer roll 70 side in the vicinity of the closest portion to the mesh belt. The mold is released from the drum recess 51 while being sucked by 75 and moved onto the transfer roll 70.

  In this way, the deposit 46 having the concavo-convex structure transferred onto the transfer roll 70 together with the mesh belt 75 is adsorbed to the mesh belt 75 on the transfer roll 70 and is transferred to the vacuum conveyor 80 (the lowermost end of the transfer roll 70). And is transferred to the vacuum conveyor 80 by suction by the vacuum box 84 at the delivery section.

  The long deposit 46 obtained in this way is cut at a predetermined interval to continuously produce the absorbent core precursor 49. Subsequently, the absorptive core precursor 49 is compressed by the pressurization means 90, and the thickness of the deposit 46 which comprises the absorptive core precursor 49 is positively reduced, and the target absorptive core 41 is obtained. As shown in FIG. 9, the pressurizing means 90 includes a pair of rolls 91 and 92, and is configured to pressurize an object to be pressurized introduced between the rolls 91 and 92 from the upper and lower surfaces and compress in the thickness direction. .

When the absorbent core precursor 49 is compressed by the pressurizing means 90, the portion (region 54 corresponding portion) 46b and the portion (region 55 corresponding portion) 46c having a relatively large liquid absorbing material and a large thickness are formed in the liquid absorbing material. It is compressed more strongly than a portion (a portion corresponding to the non-breathable member 53) 46a having a relatively small 45 and a small thickness. As a result, in the absorbent core manufactured using the manufacturing apparatus described above, the portion (region 54 corresponding portion) 46b (convex portion) and the portion (region 55 corresponding portion) 46c of the deposit 46 are the absorbent core 41. In the absorbent core 41, the relatively high density basis weights 214 a and 224 a and the non-blocking regions 216 and 226 in the deposit 46, and the portion 46 a (concave portion) in the deposit 46 is relatively in the absorbent core 41. The low basis weight portions 214b and 224b have a low density.
The absorbent core 22 is obtained, for example, by laminating the first absorbent core 210 and the second absorbent core 220 obtained in this way, and covering the upper and lower surfaces with the core wrap sheet 24 by a known method. .

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment.
For example, the absorbent core 22 in the above embodiment has the lateral grooves 224d and 214d communicating with the central through hole 230 in the lower part of the second absorbent core 220 and the lower part of the first absorbent core 210, respectively. For example, like the absorbent core 22 ′ shown in FIG. 12, the lateral groove 224d is formed in the lower part of the second absorbent core 220, while the lateral groove 214d is not formed in the lower part of the first absorbent core 210. Things can also be used. Moreover, as an absorptive core, you may use what consists only of the 1st absorptive core 210 shown in FIG. In this case, the absorbent core has the central through hole 230 and the lateral groove 214d communicating with the central through hole 230, but has the low basis weight portion 21b and the back sheet 23 on the skin contact surface side and the non-skin contact surface side of the lateral groove 214d. It will be a thing.

  The number of lateral grooves connected to the central through hole 230 and extending in the width direction is preferably 3 or more, more preferably 5 or more, for each of the left and right sides of the central through hole 230. Preferably it is 8 or more, and it is preferable that it is 20 or less, More preferably, it is 15 or less, More specifically, 3-20 is preferable and 5-15 is more preferable. Further, the lateral groove 214d or 224 extending from the central through hole 230 in the width direction X of the absorbent main body 20 is such that the length in the width direction X of the absorbent main body 20 is the length of one high basis weight portion. Instead, it may have a length of two adjacent high basis weight portions, a length of three adjacent high basis weight portions, or a length longer than that.

  In addition, the central through hole 230 preferably has a length that does not reach either end of the absorbent core 22 in the longitudinal direction, but may have reached one end or both ends of the absorbent core 20 in the longitudinal direction.

  A plurality of central through holes 230 may be formed side by side in the width direction of the absorbent core. In this case, the central portion of the absorbent main body in which a plurality of central through-holes 230 are formed is formed by dividing the width of the absorbent core into three equal parts in the width direction, and the central region and the pair of side regions. This is the central area when divided into Moreover, it is preferable that the plurality of central through-holes 230 to be formed are arranged on a target with respect to a center line obtained by dividing the width of the absorbent core into two in the width direction. It is preferable that the lateral grooves are arranged so as to communicate with each other.

  The absorbent core 22 may be a laminate of the first absorbent core 210 and the second absorbent core 220 covered with a liquid permeable sheet made of tissue paper, nonwoven fabric, or the like.

  The absorbent article of the present invention may be a so-called unfolded disposable diaper instead of a pants-type disposable diaper, or a pants-type sanitary napkin.

This invention discloses the following absorbent articles further regarding said embodiment.
<1> An absorbent article having an absorbent main body including a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet,
The absorbent core has a through hole extending in the longitudinal direction in the center in the width direction of the absorbent main body, and has a plurality of lateral grooves extending in the width direction of the absorbent main body from the through hole,
The transverse groove is an absorbent article in which an absorbent layer is present at least on the skin contact surface side of the internal space of the groove.

<2> The absorbent article according to <1>, wherein the transverse groove has an absorbent layer on a skin contact surface side and a non-skin contact surface side of an internal space of the groove.
<3> The absorbent core includes a first absorbent core and a second absorbent core laminated on the skin contact surface side, and the lateral groove is formed in a lower portion of the second absorbent core. The absorbent article according to <2>.
<4> The absorbent article according to <3>, wherein the transverse groove is also formed in a lower portion of the first absorbent core.
<5> The first absorbent core extends outward from the periphery of the second absorbent core, and the outer shape of the first absorbent core is larger than that of the second absorbent core. Or an absorbent article according to claim 1.

The <6> 2nd absorptive core is adjacent to the high basic weight part which has the convex shape which has relatively high basic weight, and protruded toward the non-skin contact surface side, and is relative. The absorptivity according to any one of <3> to <5>, wherein the basis weight is low and the low basis weight portion is recessed from the non-skin contact surface side toward the skin contact surface side. Goods.
The <7> 2nd absorptive core is an absorbent article of any one of said <6> in which the said high basic weight part and the said low basic weight part are integrally molded.
<8> The second absorbent core according to any one of <3> to <7>, wherein the non-skin contact surface side has an uneven shape and the skin contact surface side is flat. Absorbent articles.
<9> The absorption according to any one of <6> to <8>, wherein a plurality of the low basis weight portions of the second absorbent core extend in parallel with the longitudinal direction of the second absorbent core. Sex goods.

<10> The absorptivity according to any one of <6> to <9>, wherein a plurality of the low basis weight portions in the second absorbent core extend in the width direction of the second absorbent core. Goods.
<11> The <6> to <10>, wherein the low basis weight portion in the second absorbent core has an orthogonal lattice shape extending in the longitudinal direction and the width direction of the second absorbent core. 2. The absorbent article according to 1.
<12> The absorbent article according to any one of <6> to <11>, wherein the second absorbent core has the high basis weight portion located in a lattice formed by the low basis weight portion. .
<13> The second absorbent core has a longitudinal groove extending in the longitudinal direction of the absorbent core and a lateral groove extending in the width direction of the absorbent core 22 in the lower part of the second absorbent core due to the presence of the low basis weight portion. The absorbent article according to any one of <6> to <12>, wherein is formed.
<14> In the plan view of the second absorbent core, the lateral groove located on both sides of the central through-holes 225 and 230 has one end in the width direction X of the absorbent core opened to the inner wall surface of the central through-hole. And the other end communicates with the longitudinal groove.
<15> On the non-skin contact surface side of the inner space of the lateral groove formed in the lower part of the second absorbent core, there is a flat skin contact surface of the first absorbent core, The absorbent article according to any one of <3> to <14>, wherein an absorbent layer is present on the skin contact surface side and the non-skin contact surface side of the internal space.

The <16> 2nd absorptive core is described in any one of said <6>-<15> comprised from the block area | region which consists of the said high basic weight part and the said low basic weight part, and a non-blocking area | region. Absorbent articles.
<17> The absorbent article according to <16>, wherein the non-blocking region is disposed on the outer side in the longitudinal direction and the outer side in the width direction of the block region in the second absorbent core.
<18> The absorbent article according to any one of <16> to <17>, wherein the non-blocking region of the second absorbent core surrounds the entire periphery of the blocking region.
<19> In the block region, a vertically long central through hole is formed along the longitudinal center line CL at a position on the longitudinal center line CL of the second absorbent core. The absorbent article according to any one of ~ <18>.

The <20> 1st absorptive core is adjacent to the high basic weight part which has a convex shape which has relatively high basic weight, and protruded toward the non-skin contact surface side, and is relative. <3> to <19>, wherein the basis weight is low and has a low basis weight portion that is recessed toward the skin contact surface side and is recessed toward the skin contact surface side. Absorbent articles.
The <21> 1st absorptive core is an absorbent article as described in said <20> in which the said high basic weight part and the said low basic weight part are integrally molded.
<22> The first absorbent core according to any one of <3> to <21>, wherein the non-skin contact surface side has an uneven structure and the skin contact surface side is flat. Absorbent article.
<23> The absorptivity according to any one of <20> to <22>, wherein a plurality of the low basis weight portions in the first absorbent core extend in parallel with the longitudinal direction of the first absorbent core. Goods.
<24> The absorptivity according to any one of <20> to <23>, wherein the plurality of low basis weight portions in the first absorbent core extend in the width direction of the first absorbent core. Goods.
<25> The <20> to <24>, wherein the low basis weight portion in the first absorbent core has an orthogonal lattice shape extending in the longitudinal direction and the width direction of the first absorbent core. 2. The absorbent article according to 1.

The <26> 1st absorptive core is an absorptive article given in any 1 of the above <20>-<25> in which the high basic weight part is located in the lattice formed of the low basic weight part.
<27> The first absorbent core has a longitudinal groove extending in the longitudinal direction of the absorbent core and a lateral groove extending in the width direction of the absorbent core at the lower part of the first absorbent core due to the presence of the low basis weight portion. The absorbent article according to any one of <20> to <26>, which is formed.
<28> In the plan view of the first absorbent core, the transverse groove located on both sides of the central through-holes 215 and 230 has one end in the width direction X of the absorbent core opened to the inner wall surface of the central through-hole. And the other end communicates with the longitudinal groove.
<29> The back sheet is present on the non-skin contact surface side of the inner space of the lateral groove formed in the lower part of the first absorbent core, and the lateral groove is on the skin contact surface side of the inner space. The absorbent article according to <27> or <28>, wherein the absorbent layer and the back sheet are present on the non-skin contact surface side.
The <30> 1st absorptive core is described in any one of said <20>-<29> comprised from the block area | region which consists of the said high basic weight part and the said low basic weight part, and a non-blocking area | region. Absorbent articles.

<31> The absorbent article according to <30>, wherein the non-block region is disposed over the entire region in the longitudinal direction at positions on both left and right sides of the block region.
In the <32> block region, a vertically long central through hole is formed along the longitudinal center line CL at a position on the longitudinal center line CL of the first absorbent core. Or the absorbent article as described in <31>.
<33> In the first absorbent core or the second absorbent core, preferably the first absorbent core and the second absorbent core, the basis weight of the low basis weight part is based on the basis weight of the high basis weight part. The ratio is any one of the above items <6> to <32>, wherein the lower limit is preferably 1%, more preferably 3%, and the upper limit is preferably 80%, more preferably 70%. 2. The absorbent article according to 1.
<34> In the first absorbent core or the second absorbent core, preferably the first absorbent core and the second absorbent core, the high basis weight portion not only has a larger basis weight than the low basis weight portion. The absorbent article according to any one of <6> to <33>, wherein the thickness is also increased.
<35> In the first absorbent core or the second absorbent core, preferably the first absorbent core and the second absorbent core, the ratio of the thickness of the low basis weight part to the thickness of the high basis weight part is The lower limit is preferably 2%, more preferably 3%. The upper limit is preferably 80%, and more preferably 70%, according to any one of <6> to <34>.

<36> The above-described absorbent core, wherein the formation positions of the crotch high basis weight part group of the first absorbent core and the crotch high basis weight part group of the second absorbent core are matched. The absorbent article according to any one of <35>.
<37> In the absorbent core, the formation positions of the back side high basis weight part group of the first absorbent core and the back side high basis weight part group of the second absorbent core are also matched <3 The absorbent article according to any one of> to <36>.
<38> In the absorbent core, the positions of the central through hole formed in the first absorbent core and the central through hole formed in the second absorbent core are matched with each other. > Any one of>.
<39> The transverse groove formed in the lower part of the first absorbent core is formed by shifting the transverse groove formed in the lower part of the second absorbent core from the position in the longitudinal direction of the absorbent body <4. >-<38> The absorbent article <40> according to any one of <38>, comprising an exterior body located on the non-skin contact surface side of the absorbent main body, the exterior body comprising an inner layer sheet and an outer layer sheet; The absorbent article according to any one of <1> to <39>, comprising an elastic member fixed between these two sheets.

<41> In the exterior body, both side edge portions of the portion located on the ventral side portion and both side edge portions of the portion located on the back side portion are joined to each other to form a waist opening portion and a pair of leg opening portions. The absorbent article according to any one of <1> to <40>.
<42> The absorbent article according to any one of <1> to <41>, wherein the absorbent article is a pants-type disposable diaper.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

I) Production of absorbent core <Example>
The absorbent core of the example was formed by the following method.
Each of the first absorbent core (lower layer core) and the second absorbent core (upper layer core) having the following basis weight is made into an absorbent body manufacturing apparatus (apparatus for laminating a pulp polymer on a sucked rotating drum). Manufactured by.
First absorbent core (lower core) 230 g / m ² (pulp 100 g / m ² , polymer 130 g / m ² )
In the production of each of the first absorbent core and the second absorbent core, the second absorbent core (upper core) 400 g / m ² (pulp 180 g / m ² , polymer 240 g / m ² ) A metal plate capable of forming a film was affixed to a rotating drum, and a central through hole was formed so that a pulp polymer was not laminated on a through hole portion having a width of 7 mm and a length of 150 mm at the center in the width direction. The second absorbent core (upper core) has a thickness of 5 mm × 6 (two of which are arranged at the end of each through hole) communicating with the central through hole at equal intervals. A different metal plate was pasted together with a metal plate for forming a through hole to form the central through hole and the lateral groove at the same time. The low basis weight part of the lateral groove part has a basis weight of 200 g / m ² .

The upper layer core and the lower layer core were overlapped so that the through-holes overlapped to form an absorbent body having a width of 135 mm and a length of 360 mm, and included in tissue paper (16 g / m ² ). Further, an air-through nonwoven fabric (25 g / m ² ) as a top sheet and a waterproof film (20 g / m ² ) as a back sheet were joined and integrated with a hot melt adhesive.

  Each of the second absorbent cores in the obtained composite sample for evaluation has a relatively high basis weight, a high basis weight portion having a convex shape protruding toward the non-skin contact surface side, and the high basis weight. A low basis weight portion that is adjacent to the portion and has a relatively low basis weight and is recessed from the non-skin contact surface side toward the skin contact surface side, and the second absorbent core has a recessed low By the basis weight portion, the lateral groove that communicates with the central through hole in which the central through hole of the first absorbent core and the central through hole of the second absorbent core are overlapped is formed in the lower part of the second absorbent core. Has been.

<Comparative example>
The absorbent core of the comparative example was formed by the following method.
Each of the first absorbent core (lower layer core) and the second absorbent core (upper layer core) having the following basis weight is laminated with an absorbent body manufacturing apparatus (pulled polymer on a sucked rotating drum). Device).
First absorbent core (lower core) 230 g / m ² (pulp 100 g / m ² , polymer 130 g / m ² )
Second absorbent core (upper core) 400 g / m ² (pulp 180 g / m ² , polymer 240 g / m ² )
At the time of manufacturing each of the first absorbent core and the second absorbent core, a metal plate capable of forming a through hole is pasted on the rotary drum in advance, and a through hole portion having a width of 7 mm × a length of 150 mm at the center in the width direction. A central through hole was formed so that the pulp polymer was not laminated on the surface.
The upper layer core and the lower layer core were overlapped so that the through-holes overlapped to form an absorbent body having a width of 135 mm and a length of 360 mm, and included in a tissue (16 g / m ² ). Further, a top sheet (air-through 25 g / m ² ) and a waterproof film (20 g / m ² ) as a back sheet were joined and integrated with a hot melt adhesive.

II) Evaluation of Examples and Comparative Examples The following evaluation tests were conducted on the absorbent cores manufactured by the Examples and Comparative Examples and integrated with the topsheet and the waterproof film, and the results are shown in Table 1.
1) <Measurement of absorption rate under pressure>
An absorbent core is placed on a horizontal base, an acrylic plate with a cylindrical injection tube (inner diameter 20 mm) is placed on the center, and two weights are placed on the acrylic plate. A load of 5.6 kPa was applied to the entire absorbent core. 5.6 kPa is a load corresponding to the load applied in the sitting position of the child.
Under this state, 40 g of artificial urine is injected into the injection tube of the acrylic plate, and liquid absorption is completed at the portion where the injection tube is in contact with the surface sheet from the start of the injection (the liquid accumulated on the surface sheet disappears) ) Was measured to the second.
Thereafter, 40 g of artificial urine is again injected into the same sample, and similarly, the time from the start of injection until the liquid is completely absorbed at the portion where the injection tube is in contact with the surface sheet (the liquid disappears from the surface sheet). Was measured to the second. The results are shown in Table 1.

2) <Measurement of liquid diffusion length in the width direction>
In order to measure the liquid diffusion length, an entry is made in advance so that a predetermined position can be found in the absorber before liquid injection for the purpose of determining the point. The liquid injection point is the central point of the cylindrical injection tube.
The sample after measurement of the absorption rate under pressure was allowed to stand for 5 minutes in a pressurized state, then the pressure was released, and the diffusion length of the liquid was measured.
The diffusion length in the width direction is measured from the top of the absorbent core where the liquid absorption has been completed at a point of 80 mm and 100 mm in the longitudinal direction from the liquid injection point. In order to confirm liquid diffusion, it is preferable to color artificial urine. When colored artificial urine is used, the colored area is the liquid diffusion area.

3) <Measurement of liquid diffusion length in longitudinal direction>
In order to measure the liquid diffusion length, an entry is made in advance so that a predetermined position can be found in the absorber before liquid injection for the purpose of determining the point. The liquid injection point is the central point of the cylindrical injection tube.
The sample after measurement of the absorption rate under pressure was allowed to stand for 5 minutes in the pressurized state, and then the liquid diffusion length was measured.
The maximum length of liquid diffusion from the liquid injection point in the longitudinal direction (front and back) was measured from above the absorbent core after liquid absorption was completed. In order to confirm liquid diffusion, it is preferable to color artificial urine. When colored artificial urine is used, the colored area is the liquid diffusion area.

From the results shown in Table 1, it can be seen that the product of the present invention exhibits a good absorption rate even when the liquid is repeatedly supplied under pressure, as compared with the comparative example.
Further, it can be seen that the liquid is effectively absorbed into the absorbent core by the lateral groove continuous from the through hole by diffusing well in the width direction at a point away from the injection point. In addition, it can be understood that unnecessary liquid diffusion in the longitudinal direction does not occur by arranging a plurality of lateral grooves in the central through hole at an angle of 0 degrees.

1 disposable diaper (absorbent article)
2 Absorbent body 11 Waist opening 12, 12 Leg opening 20 Absorbent body 21 Surface sheet 21b Low basis weight 21b
22 Absorbent core 210 First absorbent core 214c Vertical groove 214d Horizontal groove 214a High basis weight portion 214b Low basis weight portion 215 Central through hole 216 Non-blocking region 220 Second absorbent core 224c Vertical groove 224d Horizontal groove 224a High basis weight portion 224b Low basis weight part 225 Central through-hole 226 Non-blocking area 230 Central through-hole 23 Back sheet 24 Core wrap sheet 30 Exterior body 31 Inner layer sheet 32 Outer layer sheet

Claims (5)

An absorbent article having an absorbent main body comprising a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet,
The absorbent core has a through hole extending in the longitudinal direction in the center in the width direction of the absorbent main body, and has a plurality of lateral grooves extending in the width direction of the absorbent main body from the through hole,
The transverse groove is an absorbent article in which an absorbent layer is present at least on the skin contact surface side of the internal space of the groove.   The absorbent article according to claim 1, wherein the lateral groove has an absorbent layer on the skin contact surface side and the non-skin contact surface side of the internal space of the groove.   The absorptive core has a first absorptive core and a second absorptive core laminated on the skin contact surface side, and the lateral groove is formed in a lower part of the second absorptive core. The absorbent article according to claim 2.   The absorptive article according to claim 3 in which said transverse groove is also formed in the lower part of the 1st absorptive core.   The horizontal groove formed in the lower part of the 1st absorptive core is formed by shifting the lateral groove formed in the lower part of the 2nd absorptive core from the position in the longitudinal direction of an absorptive main part. Sex goods.

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