JP2011255116A - Absorptive article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorptive article having an absorber with roughness and fineness whose high density section is used to attach a surface sheet closely with a shallow emboss, corresponding to fine difference of unevenness being more likely to happen in the absorber with roughness and fineness, and having liquid diffusion and shape retention properties which are characteristics of the absorber having the compartmented roughness and fineness, furthermore, having flexibility.SOLUTION: An absorptive article includes a surface sheet 1 mounted on a skin contact surface side, a back surface sheet 2 mounted on a skin non-contact surface side, and an absorber 3 between both sheets, and the absorber has a longitudinal direction and a width direction orthogonal to the longitudinal direction, and at least center part of the width direction is composed of a plurality of band-like high density sections 33 and a plurality of band-like low density sections 32 which extend to the longitudinal direction and are mounted alternately to the width direction, and a plurality of dents 4 are formed in at least one band-like high density section of the absorber, and the absorber and the surface sheet are joined at the dent.

Description

  The present invention relates to absorbent articles such as sanitary napkins, disposable diapers, and incontinence pants.

  In absorbent articles such as sanitary napkins, the material and structure of each member have been improved to improve its function and wearing feeling. In particular, the absorber is a member that plays an important role in absorbing and holding liquid, and has been proposed in which changes and improvements are added from various aspects.

  For example, Patent Document 1 discloses a material processed into a slightly special shape in which embossing is performed from the non-skin contact surface side of the absorber to form a large number of uneven portions. And in the skin contact surface side, it has the crimping | compression-bonding part to which the said absorber and the said surface sheet are joined. The embossed absorbent body is partitioned across the surface direction into a pressed dense portion and a non-pressed rough portion, and the fibers of the absorbent body are dense using the rough structure. The diffusivity in the liquid surface direction is enhanced by the capillary force acting strongly on the part. Thereby, a liquid can be effectively spread | diffused on a surface and an absorption amount can be increased as the whole absorber. Further, as described above, the adhesiveness of the topsheet to the absorber is enhanced by the presence of the pressure-bonding portion that fixes the topsheet to the absorber.

Japanese Patent No. 4229869

By the way, the inventor of the present application has further investigated the absorber (Japanese Patent Application No. 2008-316309) in which the high-density portions and the low-density portions extending in a streak shape previously developed by the applicant of the present application are partitioned alternately. In particular, it has been found that when the high density portion is embossed from the surface sheet side, stable adhesion to the surface sheet can be obtained even with shallow embossing. As a result, it has been found that good adhesion between the topsheet and the absorber can be realized. In addition, when the absorbent body is dense and dense, there is a tendency for minute steps to be formed in the thickness between the high density portion and the low density portion. Even in such a case, particularly the adhesion of the surface sheet is ensured. The knowledge that it was easy to do and can respond suitably was acquired.
The present invention has been made on the basis of the above-mentioned knowledge and idea, and can utilize the high-density portion of the coarse and dense absorbent body to allow the surface sheet to be in close contact with shallow embossing. In addition, it has the liquid diffusibility and shape retention characteristic of the absorber with the densely divided area, and the absorber also has flexibility. It is an object to provide an absorbent article.

  The present invention is an absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between the two sheets, the absorbent body Has a longitudinal direction and a width direction perpendicular thereto, at least a central portion in the width direction extending in the longitudinal direction, and a plurality of strip-shaped high-density portions and a plurality of strip-shaped low-density portions arranged alternately in the width direction An absorbent article in which a plurality of hollow portions are formed in at least one belt-like high-density portion of the absorbent body, and the absorbent body and the topsheet are joined in the hollow portion. This solves the above problem.

  The absorbent article of the present invention uses a high-density portion of a coarse and dense absorbent body, can adhere the surface sheet with shallow embossing, and has a minute thickness that tends to occur in the coarse and dense absorbent body described above. It has an excellent effect that it corresponds to a step and has liquid diffusibility and shape retention, which are the characteristics of a densely divided absorbent body, and the absorbent body also has flexibility.

It is the partially notched perspective view which showed typically the sanitary napkin as one Embodiment in this invention from the skin contact surface direction. It is an expanded sectional view of the II-II line section shown in Drawing 1, (i) is a section showing the case where a surface sheet has adhered to a hollow part, and (ii) is skin contact of a hollow part It is the cross section which showed the case where the surface sheet of the surface side has peeled. It is process explanatory drawing which outlines and shows the state before and after the press roll process at the time of manufacture of the absorber of one Embodiment of this invention. (A) is a perspective view which shows the recessed part for accumulation | stacking which has a groove part in a bottom face part, (b) is sectional drawing which shows the state in which the fiber material accumulated in the recessed part for accumulation | storage. (A) is a perspective view which shows the deposit body (manufacturing intermediate body) which has a convex-shaped part, (b) is typically the absorber which has the density manufactured by using the deposit body of (a). It is a perspective view shown. It is an expanded sectional view which expands and shows the section of the surface sheet of the sanitary napkin in the present invention.

  FIG. 1 is a partially cutaway perspective view showing a sanitary napkin as an embodiment of an absorbent article according to the present invention from the skin contact surface direction. FIG. 2 is an enlarged cross-sectional view taken along the line II-II shown in FIG. 1, (i) is a cross-section showing a case where the surface sheet is in close contact with the hollow portion in the low density portion, and (ii) It is the cross section which showed the case where the surface sheet by the side of a skin contact surface of the hollow part in a low-density part has peeled.

  In the sanitary napkin 10 of the present embodiment, the absorbent body 3 is bonded and disposed on the skin contact surface side of the back sheet 2 with an adhesive or the like, and the absorbent body on the skin contact surface side of the back sheet 2 is further provided. 3, the side sheets 8 are in contact with and joined to the back sheet 2 at the outer sides of both sides in the longitudinal direction. The surface sheet 1 is sandwiched between the back sheet 2 and the side sheet 8 at the portion where the back sheet and the side sheet are in contact, and the surface sheet 1 is further inward in the width direction (X direction) than the absorber 3. It arrange | positions so that it may be located in the skin contact surface side. Thus, the peripheral seal G formed on the peripheral portion of the napkin outside the absorbent body 3 does not hinder the overall stretchability, and the top sheet 1, the back sheet 2 and the The side sheets 8 are joined by heat sealing or the like. The side sheet 8 has a portion that is not joined, and forms a pocket 83 from the free end 81 of the side sheet toward the peripheral seal G, and has an effect of preventing lateral leakage of liquid or the like. In addition, in the widthwise left and right side portions of the sanitary napkin 10 in the present embodiment, blade portions 82 having side sheets 8 extend outward in the width direction of the sanitary napkin 10, and this portion is shorts. The sanitary napkin 10 is fixed to the shorts by being wound around the non-skin contact surface side of the crotch.

  On the skin contact surface side of the sanitary napkin 10 in the present embodiment, a leak-proof groove 5 squeezed from the skin contact surface side of the topsheet 1 to the absorber 3 is provided. The leak-proof grooves 5 are disposed on the left and right sides in the width direction around the excretion portion at the center in the longitudinal direction of the absorber 3, and the two leak-proof grooves 5 gradually become closer to the front and rear ends of the absorber 3. The absorber 3 curves toward the center, and the front end and the rear end coincide with each other. In other words, the leak-proof groove 5 is arranged on the skin contact surface side of the sanitary napkin 10 continuously in an endless ring shape in a plan view. Further, the shape of the leak-proof groove 5 is not particularly limited. In the present embodiment, the leak-proof groove 5 has a front end and a rear end that coincide with each other and is continuous in an endless ring shape. It is preferable that it is appropriately determined according to the application. The excretory part is a part that directly receives excretion of menstrual blood or vaginal discharge and its vicinity.

  Details regarding the materials and dimensions of the top sheet 1, the back sheet 2, the side sheet 8, and the absorber 3 will be described later. In the present embodiment, the top sheet 1 uses a combination of fibers that are shape-stable to heat and heat-shrinkable fibers. Although not shown, a heat-stable fiber layer is disposed on the skin surface side of the top sheet, a heat-shrinkable fiber layer is disposed on the non-skin surface side, and the heat of the fibers in the layer on the non-skin contact surface side is illustrated. Due to the shrinkage, minute irregularities are formed in the fiber layer on the skin side, and the contact area with the skin surface is reduced. Details of the surface sheet will be described later. Further, as the back sheet 2, a breathable moisture permeable film is used as a single layer. Absorbent body 3 includes an absorbent core made of a fiber material such as pulp fiber or an absorbent core made by holding an absorbent polymer between fibers of the absorbent core, and a core wrap sheet made of tissue paper or a water-permeable nonwoven fabric. (Not shown). Moreover, the adhesive (not shown) for fixing the sanitary napkin 10 to clothing is applied to the non-skin contact surface side of the back sheet 2. The sanitary napkin 10 is adhesively fixed to the user's clothes by the adhesive. The sanitary napkin 10 according to this embodiment is arranged with its top sheet side facing the wearer's skin contact surface and its vertical direction from the lower abdomen to the buttocks, in other words, the width direction of the left and right feet. Wear it in the direction of the connecting line.

  In the present invention, unless otherwise specified, the side in contact with the human body is referred to as the skin surface side or the skin contact surface side or the surface side, and the side in contact with the underwear is the non-skin surface side or the non-skin contact surface side or the back surface side. That's it. In addition, the direction positioned on the front side of the human body when worn is referred to as the front, and its end is referred to as the front end, and the direction positioned on the rear is referred to as the rear, and the end is referred to as the rear end. Moreover, the normal line direction of the surface or back surface of an absorbent article is called thickness direction, and the quantity is called thickness. Further, a direction having a relatively long length in a plan view of the absorbent article is referred to as a longitudinal direction, and a direction orthogonal to the longitudinal direction is referred to as a width direction. The longitudinal direction typically coincides with the front-rear direction of the human body when worn.

  The absorbent body 3 of the present embodiment is divided into three types of regions as viewed in the width direction, and the three types of regions extend in a band shape in the longitudinal direction from the front end to the rear end of the absorber 3. A pair of side low density portions 31 are disposed on both the left and right sides of the absorbent body 3 in the width direction, and the band-like low density portion 32 and the belt-like high density portion 33 are sandwiched between the pair of side portion low density portions 31. It is formed repeatedly alternately in the direction. Although the detailed manufacturing method etc. of the absorber 3 are mentioned later, as for the said division of the absorber 3, the shape of the skin contact surface side of the absorber precursor 3a before manufacture has a some convex part in the thickness direction. (See FIG. 5A). The absorbent body precursor 3a having the convex portion formed on the skin contact surface side is compressed by the press roll 66 in the thickness direction so as to have a constant thickness. If it does so, the convex part 33a by the side of a skin contact surface in the absorber precursor 3a will become the strip | belt-shaped high density part 33 in the absorber 3 after the density of the fiber of a thickness direction becomes high. Moreover, the side part 31a in the width direction of the absorber precursor 3a becomes the side low density part 31 of the absorber 3 after processing, and the intermediate part 32a in the width direction of the convex part 33a becomes the belt-like low density part 32. In the belt-like high density portion 33, the density of the fiber is high and the resilience in the fiber thickness direction is low. On the other hand, the side low density part 31 and the belt-like low density part 32 have a low fiber density and high resilience in the thickness direction. Therefore, in the absorbent body 3 after being compressed by the press roll 66 (roll 66a, roll 66b), the side low density part 31 and the belt-like low density part 32 in the thickness direction are made of the belt-like high density part 33 by the spring back of the fiber. The shape is slightly thicker than that, and there is a small step between the high density portion and the low density portion of the fiber. In addition, the division | segmentation of the strip | belt-shaped high density part 33 in this embodiment, the strip | belt-shaped low density part 32, and the side part low density part 31 has shown typically an example, The arrangement | positioning order is not specifically limited, It is preferable that the distance and shape are appropriately determined according to needs. The ultra-low density side portion includes a portion where the fiber density is lower than that of the belt-like low density portion or the same fiber density, and the fiber density does not necessarily have to be low in this portion.

  When the coarse and dense gradient as described above is applied and excreted into the partitioned absorber 3, the excreted liquid passes through the top sheet 1 and then moves to the absorber 3. And the absorber 3 absorbs and holds a liquid from the skin contact surface side. The absorber 3 in this embodiment is partitioned into a belt-like high density portion 33, a belt-like low density portion 32, and a side portion low density portion 31. The liquid absorbed in the absorber 3 moves to the belt-like high density portion 33 higher than the belt-like low density portion 32 and the side low density portion 31 according to the order of the density of the fibers. This is because the liquid moves from the other portion having a low capillary force to the belt-like high density portion 33 in which the capillary force is increased due to the high fiber density. The liquid that has migrated to the strip-shaped high-density portion 33 diffuses along the longitudinal direction of the strip-shaped high-density portion 33 as the amount thereof increases. Therefore, even if there is repeated excretion in the vicinity of the excretion part P (see FIG. 1), the effective diffusion transfer of the liquid to the front and rear ends in the longitudinal direction is caused by the diffusion action of the liquid of the partitioned absorber 3 described above. Thus, the front and rear regions in the longitudinal direction of the absorber, which are usually difficult to use, are effectively used. As a result, while showing a larger absorption holding amount, liquid return is suppressed without retaining the liquid on a part of the absorbent body, and a comfortable wearing feeling is achieved. Further, in the present embodiment, the intermittently applied belt-like low density portion 32 is disposed outside the belt-like high density portion 33 on the outer side in the width direction of the napkin, and the density is lower than that of the belt-like low density portion 32. By adopting the low density portion 31, the liquid transfer can be preferentially guided in the longitudinal direction in the belt-like high density portion 33, the outward shift in the width direction can be suppressed, and side leakage can be effectively prevented. Good liquid diffusibility and side leakage prevention are obtained by the absorber 3 partitioned into portions having different densities in the width direction described above.

By the way, in the central part of the longitudinal direction and the width direction, which is in the vicinity of the excretion part of a general sanitary napkin, etc., in order to prevent twisting of the part due to peeling between the absorber and the surface sheet and liquid diffusion in the surface sheet It is conceivable to hit a plurality of pin embosses from the sheet side to the absorber, thereby joining them together. When a hollow portion formed by the pin embossing is applied to a general absorbent body, a normal absorbent body has a low stress. Therefore, in order to form a hollow portion having a sufficient bonding force, a considerable pressing stress is applied. It is necessary to secure it. For example, a deep embossing pin embossing must be applied so that the depth is 98 to 99% of the thickness of the absorber. However, the periphery of the recessed portion formed at such a depth tends to be hard. In addition, it is conceivable that the surface sheet pulled by pin embossing applied deeply is torn. On the other hand, if an attempt is made to obtain a high stress over the entire absorbent body, the absorbent body is hard and inferior in wearing feeling without flexibility.
On the other hand, according to the present embodiment, the concave portion 4 formed in the absorber 3 partitioned into differently dense and dense portions described below, the surface sheet and the absorber are sufficiently joined by shallow embossing at that portion. Sex is realized. In addition, a good wearing feeling can be obtained without excessive curing around the entirety of the absorbent body or the depression. Furthermore, as described above, the side leakage prevention property and the liquid diffusion property in the longitudinal direction can be realized by the action of the density of the specific fibers. In addition, it is possible to improve the adhesion between the absorber and the surface sheet in a suitable manner for the surface step due to the density gradient of the absorber. That is, the minute step as described above is likely to occur on the skin contact surface side of the absorbent body formed in a partially dense state, and in particular, the high density portion tends to be lowered. However, since a good bonding state by embossing is realized in the high density portion, a form in which the topsheet 1 and the absorbent body 3 are firmly adhered to each other in that portion is realized. With this good adhesion state, it is possible to prevent an influence on the drawability and diffusibility of the liquid or the like due to the excessive separation of the two here.

  The hollow part 4 in this embodiment has a shape opened to the top sheet side (wearer side), and has a mortar shape or a cylindrical shape squeezed from the top sheet side. The recess 4 is substantially circular in plan view, and includes a high density recess 4 a applied to the belt-like high density portion 33 of the absorber 3 and a low density recess 4 b applied to the low density portion 32. Consists of. The high-density portion dent 4a in the present embodiment is applied to the belt-like high-density portion 33 having a high fiber density, and the distortion at the time of pin embossing is small due to the high rigidity of the belt-like high-density portion 33, and therefore shallow. Sufficient pressing can be ensured even under the condition of the depression. As a result, sufficient bonding strength is ensured between the top sheet 1 and the absorber 3 even in the shallow depression 4. Therefore, it is difficult for the periphery of the high-density portion dent 4a to harden like when deeply embossed and pressed, and the worry of tearing the topsheet 1 is greatly reduced. Moreover, the surface sheet 1 and the absorber 3 joined by the high-density part hollow part 4a are the structure mentioned above because the surface sheet 1 pulled to the high-density part hollow part 4a side bites into the absorber 3. It is possible to effectively prevent the surface sheet from being lifted by the step w in the thickness direction between the belt-like high density portion 33 and the belt-like low density portion 32, and the liquid absorbency and the touch feeling of the skin contact surface are not impaired.

  On the other hand, in the low density part hollow part 4b given to the belt-like low density part 32 with a comparatively low fiber density, the pressing stress is not so high, and the bonding force between the topsheet 1 and the absorbent body 3 is shallow in embossing. In this part, since it is small, in the formed hollow part, when the surface sheet 1 and the absorber 3 which have elasticity are joined to the thickness direction (FIG.2 (i)), and when it peels (FIG. 2) In the case of being joined, it may contribute to the above-described step in the thickness direction, or in almost all, the top sheet floats in the recessed portion of the low density portion. In this way, in the case of peeling, when the excreted liquid moves to the low density part depression 4b, the liquid is put into the low density part depression 4b to which the topsheet 1 is not joined. Stay temporarily, Therefore, even if there is excretion exceeding the absorption rate of the absorber, the return of the liquid to the skin surface side is suppressed, and the sanitary napkin 10 has a skin contact surface side. Furthermore, since the topsheet 1 has been restored so as to cover the upper surface of the low-density portion dent 4b, there is no dent in that portion, so that the surface has no unevenness and is well worn. In addition to the high-density portion dent portion 4a and the low-density portion dent portion 4b, there is an intermediate dent portion 4c formed across the middle of the belt-like high-density portion 33 and the belt-like low-density portion 32. The surface sheet 1 may or may not be peeled off at that portion.

It is sufficient that at least two hollow portions 4 in this embodiment are provided on at least one strip-shaped high-density portion 33 of the liquid excretion portion C of the sanitary napkin 10, and effectively express the various functions described above. From the viewpoint, it is preferable that the depressions 4 are arranged so as to be continuous in the longitudinal direction along the belt-shaped high-density part 33, and a plurality of rows of depressions continuous in the longitudinal direction are formed in the width direction. The row is preferably formed together with the strip high density portion 33 and the strip low density portion 32. In particular, it is preferable that the recesses adjacent to each other in the width direction are shifted from each other in the longitudinal direction so as not to be aligned in the width direction.
Further, the liquid excretion part C is a central part in the longitudinal direction of the sanitary napkin 10 including the liquid excretion part, and the sanitary napkin 10 can be partitioned into three regions in the longitudinal direction with the part as the center. The longitudinal ends of C are defined as a front part F and a rear part R, respectively. The front part F and the rear part R are names for convenience, and it is not always necessary to wear a sanitary napkin in that direction. 50-120 mm is preferable and, as for the length in the longitudinal direction of the liquid excretion part C, 70-100 mm is more preferable. The length of the front portion F in the longitudinal direction is preferably 60 to 100 mm, and more preferably 80 to 90 mm. The length of the rear portion R in the longitudinal direction is preferably 60 to 300 mm, and more preferably 90 to 250 mm. Further, the ratio in the longitudinal direction (front portion F: liquid excretion portion C: rear portion R) is preferably 1: 0.6 to 1.1: 1 to 2, when the front portion F is 1, 1: More preferably, it is 0.7 to 1: 1 to 1.5.

  In this embodiment, the dents 4 are dents at intervals that are half of the interval between the dents row K (see FIG. 1) arranged at predetermined intervals in the longitudinal direction and the dents arranged in the dents row K. 4 are arranged alternately and repeatedly in the width direction of the absorber 3. That is, when a large number of the depressions 4 are projected in the longitudinal direction and the width direction (X direction), the projection images of the depressions in the K row and the depressions in the J row overlap each other. In addition, the arrangement can be appropriately selected according to the use and function, and is not particularly limited. For example, a staggered arrangement may be used. The houndstooth check arrangement means an arrangement in which the depressions 4 are formed in a plurality of rows parallel to the longitudinal direction of the absorber and the pitch of the depressions 4 in each example is shifted. Here, the arrangement in which the pitches of the depressions 4 are shifted is, in other words, an arrangement in which the projection images of the depressions 4 do not match when the depressions 4 in each row are projected in a direction orthogonal to the longitudinal direction of the absorber. It is. At this time, it is preferable that the pitch of the hollow portions 4 in the zigzag lattice arrangement coincides with every other row of the hollow portions parallel to the longitudinal direction of the absorber. That is, it is preferable that the projection images of the rows of the depressions 4 in the direction orthogonal to the longitudinal direction of the absorbent body are substantially coincident with every other row of the depressions. Further, it is more preferable that adjacent dent portion rows are shifted by approximately a half pitch between the dent portion rows. In other words, it is more preferable that the projected images are arranged approximately in the middle between adjacent recess portions.

The size of the recess 4 according to the present embodiment is not particularly limited, considering the use in sanitary napkins, the diameter d ₁ of less by an absorbent article incorporating differ recess 4 _(see FIG. 2) is 1~3mm Is preferable, and 1.2 to 2 mm is more preferable. 20-60% is preferable with respect to the thickness of the absorber to which the depth direction to which the hollow part 4 is given is preferable, and 25-50% is more preferable. The pitch _{s 1} in the width direction of the recess portion 4 in the absorbent body 3 is preferably from 3 to 15 mm, more preferably 5-12 mm, a pitch _{s 2} of the recessed portion array K in the longitudinal direction is preferably 5 to 20 mm,. 7 to 15 mm is more preferable, and the pitch s ₃ of the recessed portion row J in the longitudinal direction is preferably ₃ to 15 mm, and more preferably 5 to 10 mm. In addition, although the case where a hollow part shape was circular was shown, it is not limited to this shape, A rectangle, such as a quadrangle, a polygon, such as a triangle, a triangle, an ellipse, etc. may be sufficient, but a pitch, an area, etc. It is about the same as the range described in a circle.

The thickness and fiber density of the absorbent body 3 is not particularly limited, the thickness _{t 3} of the strip dense portion 33 which recess is not subjected is preferably from 0.5 to 8 mm, 0.7～6Mm is more preferable. Also, the fiber density _{D 33} is preferably 0.15~0.5g / cm ^3, more preferably 0.2-0.4 g / cm ^3. The length _{h 3} in the width direction of the belt-like high density portion 33 is preferably 1 to 10 mm, 1 to 7 mm is more preferable.
The thickness t ₂ of the band-shaped low density portion 32 not provided with the depression is preferably 0.5 to 7 mm, more preferably 0.7 to 5 mm, and the thickness of the band-shaped low density portion 32 is more than the band-shaped high density portion 33. It is about 0.1 to 0.5 mm thick. Also, the fiber density _{D 32} is preferably 0.03~0.2g / cm ^3, more preferably 0.05~0.15g / cm ^3. Strip length _{h 2} in the width direction of the low density portion 32 is preferably 3 to 15 mm, 5-12 mm is more preferable.
The thickness t ₁ of the side low density portion 31 is preferably 0.5 to 6 mm, and more preferably 0.7 to 5 mm. 10-25 mm is preferable and, as for length h ₁ in the width direction of the side part low density part 31, 12-20 mm is more preferable. The fiber density D ₃₁ is preferably equal to or lower than the fiber density D ₃₂ of the belt-like low density portion 32.
Although strip ratio of the fiber density _{D 33} and the fiber density _{D 32} of the strip-shaped low-density portion 32 of the high density portion 33 is not particularly limited, it is preferred that the density ratio _(D 33 _{/ D 32)} is 1.3 to 8 1.5 to 5 is more preferable. The density difference (D ₃₃ -D ₃₂ ) between the fiber density D ₃₃ of the belt-like high density portion ₃₃ and the fiber density D ₃₂ of the belt-like low density portion 32 is 0.05 g / cm ³ or more, preferably 0.07 to 0.3 g / cm ^3, it is preferable from the viewpoint of a good wearing feel and liquid diffusibility more preferably a 0.1~0.25g / cm ^3.
In addition, unless otherwise indicated, the measuring method of the thickness in this embodiment and a fiber density is based on the method shown below. It is preferable that the belt-like high-density part and the belt-like low-density part are alternately formed in the absorbent article excretion part.

[Measurement method of thickness]
Using a constant-pressure thickness meter, measure the sample thickness, and divide the weight of the fiber material contained in the measured sample by the volume of the sample (thickness x length x width) to determine the density of the fiber material at each location. calculate. In addition, KES-G5 is used as a low-pressure thickness gauge at a speed of 0.1 mm / min, and the measurement pressure (T ₀ ) is 0.5 g / cm ² . In the measurement, when the size of each part of the absorber to be measured is smaller than the measurement tip of the thickness gauge, the measurement is not larger than the measurement tip, such as measuring the adjacent belt-like high-density portions 33 side by side when measuring the belt-like high-density portion 33. To do. The side low density part can reduce the influence of the side end part (mainly) having a large thickness variation by performing measurement between the side end part and the inner end part.

[Method for measuring density of high-density part and low-density part]
Samples were prepared by cutting each part from the absorber 3 into a size of 50 mm in length and 5 mm in width, and measuring the mass of the sample using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point). To do. Using a constant-pressure thickness meter, the sample thickness is measured, and the measured mass of the sample is divided by the volume of the sample (thickness × length × width) to calculate the density of all materials at each site. In addition, the pressure at the time of measurement of the low-pressure thickness gauge is 0.5 g / cm ² , and a method for measuring the fiber weight by removing after absorption with distilled water, except for the fiber component (for example, highly absorbent polymer particles), Measurement is performed by a known method such as a method of dissolving superabsorbent polymer particles by dipping in an ascorbic acid solution.

[Measurement method of density of high density part and low density part (density of fiber material)]
The mass of the fiber material contained in the sample prepared in the same manner as described above was determined, and the density of each part (fiber material was determined in the same manner as above except that the mass of the calculated fiber material was divided by the volume of the sample. Density).

Next, the preferable manufacturing method of the sanitary napkin 10 mentioned above is demonstrated with reference to FIGS. In addition, in order to simplify description, the side low density part 31 in the absorber 3 is demonstrated as the density of the fiber same as the strip | belt-shaped low density part 32, and the thickness before a process is the same. Further, the shape of the absorbent body 3, the number of strips of the strip-shaped high density portion 33 and the strip-shaped low density portion 32, the order thereof, and the like are schematically illustrated and may not necessarily be the same as the shapes described in FIGS. Good.
FIG. 3 is a view showing an absorbent body manufacturing apparatus 6 preferably used for manufacturing the absorbent body 3 of the sanitary napkin 10. As shown in FIG. 3, the manufacturing apparatus 60 includes a rotating drum 62 in which a plurality of accumulation recesses 9 (deposition portions) are formed at predetermined intervals on the outer peripheral surface, and a fiber material toward the outer peripheral surface of the rotating drum 62. A duct 63 for supplying S in a scattered state, a fiber material supply unit 64 for supplying the fiber material S to the duct 63, and a scuffing roll 65 for scraping off an excessive amount of fiber material deposited so as to overflow the accumulation recess 9. A covering mechanism (not shown) for covering the upper and lower surfaces of the deposit (absorber precursor) 3a released from the accumulation recess 9 with the core wrap sheet 3b, and the absorber precursor 3a with the core wrap sheet 3b. The absorber continuous body obtained by coating is compressed between a pair of press rolls 66a and 66b and compressed, and the compressed absorber continuous body is dimensioned to be used for each sanitary napkin. Absorber 3 after cutting and processing A cutting device (not shown).

  The rotating drum 62 has a cylindrical shape and is driven to rotate at a constant speed in the direction of arrow A in FIG. On the outer peripheral surface of the rotary drum 62, a plurality of accumulation recesses 9, 9,. An intake fan (not shown) is connected to a non-rotating portion inside the rotating drum 62 (on the rotating shaft side), and the partitioned spaces B and E inside the rotating drum are negatively driven by driving the intake fan. Maintained at pressure. The bottom surface portion of each collecting recess 9 is formed of a mesh plate and has a large number of pores. While the individual accumulation recesses 9 pass through the spaces B and E maintained at a negative pressure, the pores at the bottom of each accumulation recess 9 function as suction holes. As shown in FIG. 4, bottom bottom portions 93 of a plurality of grooves are formed on the bottom top portion 92 of the accumulation recess 9 so as to extend in the circumferential direction of the rotary drum 62. Although omitted in FIG. 4, both the bottom upper part 92 and the bottom bottom part 93 have a mesh structure with pores.

  The duct 63 has a blowing end portion 63 a that covers a part of the outer peripheral surface of the rotating drum 62, and a blowing end portion 63 b connected to the fiber material supply device 64, and is a stacking recess located on the space B. 9 is configured to generate an air flow that flows toward the outer peripheral surface of the rotating drum 62 in the duct 63 by suction from the bottom surface portion of the rotating drum 9. The fiber material supply unit 64 includes a defibrator 64e, and a sheet-like raw material S 'such as a pulp sheet is introduced into the defibrator 64e by a nip roller 64d for supplying the raw material, and the defibrated fiber material S is ducted. It is comprised so that it may supply in 63.

  The scuffing roll 65 has a brush around it, and scrapes off the fiber material S overflowing from the accumulation recess 62 with the brush. The deposit (absorber precursor) 3 a remaining in the accumulation recess 9 without being scraped off by the scuffing roll 65 is released from the accumulation recess 9 below the rotary drum 62. The mold release from the accumulation recess 9 maintains the partitioned space D in the rotary drum 62 at a positive pressure by a pressure means (not shown), and blows out air from the pores on the bottom surface of the accumulation recess 9. , By suction from the vacuum conveyor 67 side. The covering mechanism includes a well-known transport mechanism for supplying the core wrap sheet 3b on the vacuum conveyor 67, and a deposit (absorber precursor) 3a placed on the core wrap sheet. Both side portions are folded on the deposit (absorber precursor) 3a, and the upper and lower surfaces of the deposit (absorber precursor) 3a are covered with the core wrap sheet 3b by the folding. In FIG. 3, details of the folding process are omitted, and the folded core wrap sheet 3b is also simply shown as two lines.

A method of manufacturing the above-described absorber 3 using the absorber manufacturing apparatus 6 shown in FIG. 3 will be described.
First, the rotary drum 62 and the scuffing roll 65 are rotated, and the intake fan and the pressurizing unit are operated to make the spaces B and E have a negative pressure and the space D have a positive pressure. Further, the vacuum conveyor 67, the compression device 66, and the cutting device are operated. By the operation of the intake fan, a suction force is generated on the bottom surface of the accumulation recess 9 located on the space B, and an air flow that flows toward the outer peripheral surface of the rotary drum 62 is generated in the duct 63. Then, when the fiber material supply device 64 is operated to supply the fiber material S into the duct 63, the fiber material S is in a scattered state and is placed on the air flow flowing in the duct 63, Supplied toward the outer peripheral surface.

  While the individual accumulation recesses 9 pass through the space B maintained at a negative pressure, the fiber material S supplied from the duct 63 is sucked and accumulated in each accumulation recess 9. A slightly excessive amount of fiber material is deposited on each accumulation recess 9, and the fiber material overflowing from the accumulation recess 9 is scraped off by the scuffing roll 65. The deposit (absorber precursor) 3 a remaining in the accumulation recess 9 without being scraped off by the scuffing roll 65 is released onto the core wrap sheet 3 b supplied onto the vacuum conveyor 67. FIG. 5 (a) is a diagram showing a deposit (absorber precursor) 3a released from the core wrap sheet 3b, and the deposit (absorber precursor) 3a includes an accumulation recess 9 inside. Four convex strips 33a corresponding to the four bottom bottom portions 93 are formed.

The deposited body (absorber precursor) 3a on the core wrap sheet 3b is also introduced into the compression device 66 after the surfaces having the ridges 33a are covered by both sides of the folded core wrap sheet 3b. Pressure is applied between the press rolls 66a and 66b. Thereby, the protruding item | line part 33a is crushed. The absorbent body continuum after the ridges 33a are crushed is cut by a cutting means (not shown) to form the absorbent body 3 having a size used for each sanitary napkin. In the obtained absorbent body 3, as shown in FIG. 5 (b), the portion where the ridges 33 a are crushed is a belt-like high-density portion 33, and the other portion is a belt-like low-density portion 32. ing. The sanitary napkin 10 disposes the absorbent body 3 thus obtained intermittently between the belt-shaped original fabric of the top sheet 1 and the belt-shaped raw fabric of the back sheet 2, and then around the absorber 3. It is obtained by joining the front and back sheets and then cutting to the size of the individual sanitary napkin.
For the above-described method for producing a dense absorbent body alternately extending in the longitudinal direction, the procedures and conditions described in Japanese Patent Application No. 2008-316309 can be referred to.

  As mentioned above, although 1 embodiment of the absorber of this invention, its manufacturing method, and an absorbent article was described, this invention is not restrict | limited to embodiment mentioned above, It can change suitably. For example, the belt-like high density portion and the belt-like low density portion may be formed only in a part in the longitudinal direction of the absorber. For example, it may be formed only in the liquid excretion part C of the absorber, may be formed only in the front part F and the liquid excretion part C, or may be formed only in the rear part R and the liquid excretion part C. good.

  Moreover, formation of the embossing pattern to the absorber 3 can be formed by passing between the patterned embossing roll and the flat roll. The pattern of the embossing roll is selected from a lattice shape, a dot shape, a wave shape, and the like. In the present embodiment, the above-described zigzag pattern is selected.

  As the surface sheet of the present invention, generally used surface sheets for absorbent articles such as nonwoven fabric sheets and apertured film sheets can be used. A bulky surface sheet having a two-layer structure will be described as an example of the following surface sheet. The top sheet 1 of the present embodiment is composed of a first layer 11 disposed on the skin side and a second layer 12 disposed on the absorber side (in FIGS. 1 and 2, one sheet is taken into consideration for complication of the drawings). As a sheet of). The first layer 11 and the second layer 12 are each made of a fiber assembly, and are laminated and partially joined to each other. The joint portion 13 between the first layer 11 and the second layer 12 is consolidated and has a thickness that is extremely smaller than other portions of the topsheet 1. There are a large number of convex portions 15 distributed in a pattern and a large number of concave portions 14 formed on the joint portion 13, and the convex portions 15 and the concave portions 14 are uneven on the skin side of the topsheet 1. A shape is formed.

  The fiber assembly constituting the first layer 11 is a nonwoven fabric having a fiber entanglement point Q that is heat-sealed. In addition, the nonwoven fabric which has the fiber entanglement point Q heat-seal | fused may contain the fiber which is not heat-seal | fused with another component fiber other than the fiber by which the fiber entanglement point was heat-seal | fused. In addition, the fiber assembly constituting the second layer 12 may be a non-woven fabric having no thermally entangled fiber entanglement points, or may be a non-woven fabric having a thermally entangled fiber entangled point.

  In the present embodiment, since the first layer 11 is made of a nonwoven fabric having a heat entangled fiber entanglement point Q, fiber fluff generated when using a nonwoven fabric or a fiber web having no heat fusion point is worn. Hardly occurs on the surface layer of the convex portion 15 in contact with the skin of the person. That is, the surface sheet 1 has a surface tissue strength that is not fuzzy even with respect to the movement of the wearer during wearing, and is particularly unlikely to give physical irritation to the skin of the wearer, and can always provide a comfortable wearing feeling. .

Next, the manufacturing method of the surface sheet 1 in this embodiment is demonstrated. In the manufacturing method of the present embodiment, first, a nonwoven fabric having a fiber entanglement point that has been heat-fused is bulked by hot air treatment, an apparent density is 0.004 to 0.05 g / cm ³ , and a thickness is 0.3. A bulky nonwoven fabric of ˜5 mm is obtained.

  As the fiber constituting the nonwoven fabric, a fiber made of a thermoplastic polymer material coated with a hydrophilized oil is preferably used. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. A core-sheath type or side-by-side type composite fiber made of a combination of these thermoplastic polymer materials can also be used. It is preferable to use a nonwoven fabric that does not substantially have heat shrinkability or that does not shrink at a temperature at which the second layer forming material described below starts to shrink. In addition, as a nonwoven fabric, the nonwoven fabric which has the fiber entanglement point heat-seal | fused can be especially used without a restriction | limiting.

  As the non-woven fabric, a non-woven fabric formed by a heat fusion method, a non-woven fabric formed by an airlaid method, a non-woven fabric formed by an air-through method, a non-woven fabric formed by a melt blown method, or the like can also be used. As the hot air treatment, a method of passing hot air through the front and back surfaces in the thickness direction of the nonwoven fabric is preferable.

Next, the bulky nonwoven fabric is laminated on the fiber assembly as the second layer forming material, and these are partially joined in a predetermined pattern. The method for joining the bulky nonwoven fabric and the fiber assembly is preferably heat embossing or ultrasonic embossing. By partially joining the bulky nonwoven fabric and the fiber assembly, a concave portion is formed on the joint portion 13, and a protruding portion made of the bulky nonwoven fabric is formed at a portion other than the joint portion 13. In addition, the number of the junction parts 13 is 1-15 per cm < ² >, and especially 3-10 are preferable, and the number of the heat-fusion parts of the surface sheet 1 obtained through a heat shrink process is 1-30 per cm < ² >, In particular, 5 to 20, more preferably 5 to 10 are preferable. Such a joining portion joins the upper and lower layers of the topsheet, and has a size smaller than the depression formed in the absorbent body, and does not hinder the formation of the depression. In the recess, the surface material is compressed together with the absorber to form the recess, so the surface sheet is bulky in the area without the recess, but in the recess, the surface sheet is flattened and not bulky. It has a close form and is integrated with the absorber. The distance between the joints is preferably about 0.2 to 3 mm. In order not to prevent the formation of the dents formed in the absorber from the surface sheet side, the thickness of the surface sheet is preferably thinner than the absorber thickness, and the thickness of the surface sheet is preferably 0.01 to 2 mm.

  As the fiber aggregate as the second layer forming material, a fiber aggregate that can be shrunk in the horizontal direction by a predetermined treatment can be preferably used. In particular, a latent crimpable fiber that is crimped by heat treatment is used. Those containing (including those made of 100% latent crimpable fibers) are preferred.

  As the form of the fiber assembly as the second layer forming material, the fiber web formed by the card method, the nonwoven fabric formed by the heat fusion method, the nonwoven fabric formed by the hydroentanglement method, the needle punch method was used. Non-woven fabrics, non-woven fabrics formed by a solvent bonding method, non-woven fabrics formed by a spunbond method, non-woven fabrics formed by a melt blown method, and the like.

  Then, in the composite sheet formed by partially joining the bulky nonwoven fabric and the fiber assembly, the fiber assembly is contracted in a horizontal direction (orthogonal direction of the thickness direction) by contracting fibers that contract by a predetermined treatment. Shrink. By shrinking the fiber assembly in the horizontal direction, the distance between the fibers at the upper part of the raised portion is expanded, the apparent density of the upper part is lowered, and at the same time, the distance between the joined parts 13 and 13 is lowered. , 13 increases the apparent density of the fiber assembly. The fiber aggregate is preferably contracted by 15 to 80% by area ratio. Thus, the surface sheet 1 in this embodiment is obtained. In addition, about the surface sheet 1 mentioned above as an example, Unexamined-Japanese-Patent No. 2003-250836 can refer.

The back sheet 2 may be a moisture permeable film alone, a laminate of a film and a nonwoven fabric, or a water-repellent nonwoven fabric (such as SMS or SMMS). It is most preferable to use a moisture permeable film alone as a leak-proof material from the viewpoint of cost and matching with an anti-displacement adhesive. As the film material in this case, a film obtained by melt-kneading a thermoplastic resin and an inorganic filler that is not compatible with the thermoplastic resin and extruding the film to a predetermined size to make fine holes, or essentially moisture The non-porous film which is highly compatible and can discharge water vapor, such as a permeable membrane. In order to realize a leak-proof layer that sufficiently exhibits the performance of moisture discharge related to the present invention and does not ooze out moisture, the moisture permeability should be in the range of 0.7 to 3.0 g / 100 cm ² hr. Is preferable, and it is still more preferable that it exists in the range of 1.0-2.5. From the standpoint of sufficiently improving the smoothness, it is most preferably from 1.5 to 2.5. Moreover, in order to be able to use without trouble, such as a tear of a film, a film basic weight is 18-70 g / m < ² >, More preferably, it is 25-60 g / m < ² >. Moreover, a preferable inorganic filler compounding quantity is 30-65 mass% as a mass% of the filler with respect to the mass of the whole film, More preferably, it is 40-60 mass%.

The absorbent body 3 is composed of an absorbent core made of a fiber material such as pulp fiber or an absorbent core made by holding a water-absorbing polymer between fibers of the absorbent core, and a core wrap sheet made of tissue paper or a water-permeable nonwoven fabric. (Not shown).
As the fiber material constituting the absorbent core, various materials conventionally used for absorbent articles such as sanitary napkins, panty liners, disposable diapers and the like can be used without particular limitation. For example, pulp fibers In addition, short fibers of cellulosic fibers such as rayon fiber and cotton fiber, and short fibers of synthetic fiber such as polyethylene are used. These fibers can be used alone or in combination of two or more. Moreover, it is preferable that the fiber material is entirely or partly pulp fiber, and the ratio of the pulp fiber in the fiber material is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, More preferably, it is 100 mass%. In addition to a fiber material, you may mix | blend a deodorizer, an antibacterial agent, etc. with an absorptive core as needed. Moreover, you may mix | blend a water absorbing polymer.

  The absorbent article of the present invention is not limited to the above embodiment, and the present invention can be applied to this type of absorbent article, for example, an incontinence pad, an incontinence liner, and the like. Moreover, it is effective not only for menstrual blood but also urine, orimono, loose stool, and the like. Moreover, you may incorporate a member suitably according to a use and a function other than the surface sheet 1, the absorber 3, and the back surface sheet 2. FIG. In addition, the material of the top sheet 1, the absorbent body 3 and the back sheet 2 of the sanitary napkin of the above embodiment, the conditions in the manufacturing method, and the dimensional terms of the product are not particularly limited, and are used in ordinary sanitary napkins and the like. Various materials can be used.

DESCRIPTION OF SYMBOLS 1 Top sheet 11 1st layer 12 2nd layer 2 Back surface sheet 3 Absorber 31 Side part low density part 32 Band-like low density part 33 Band-like high density part 3a Absorber precursor 31a Side part low density part precursor 32a Band-like low density Part precursor 33a Band-shaped high-density part precursor 4 Indentation part 4a High-density part indentation part 4b Low-density part indentation part 5 Leak-proof groove 60 Absorber manufacturing apparatus 62 Rotary drum 63 Duct 64 Fiber material supply part 65 Scuffing roll 66 Compression Equipment 67 Vacuum conveyor 8 Wing part 9 Concave part 10 Sanitary napkin S Textile material

Claims (5)

An absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between the two sheets,
The absorbent body has a longitudinal direction and a width direction orthogonal to the longitudinal direction, and at least a central portion in the width direction extends in the longitudinal direction and is arranged alternately in a plurality of belt-like high density portions and a plurality of belt-like portions. A plurality of hollow portions are formed in at least one band-shaped high-density portion of the absorbent body, and the absorbent body and the topsheet are joined at the hollow portion. Absorbent article.   The left and right side portions in the width direction of the absorber are side low density portions that are equal to or lower in density than the belt-like low density portions, and groove portions extending in the longitudinal direction of the absorber are formed in the side low density portions. The absorptive article according to claim 1 formed.   The absorbent article according to claim 2, wherein the side low density part has a density lower than that of the belt-like low density part.   The absorptive article according to any one of claims 1 to 3 in which said hollow parts are scattered apart from each other in a longitudinal direction and a width direction of an absorber in a plan view.   The absorbent article according to any one of claims 1 to 4, wherein a thickness of the absorbent body is different between the belt-shaped high density portion and the belt-shaped low density portion provided in the absorbent body.

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