JP5175651B2 - Absorbent article and manufacturing method thereof - Google Patents

Description

  The present invention relates to an absorbent article including an absorbent body, a top sheet, and a back sheet, and a second sheet having a storage / diffusion effect of urine or the like disposed between the absorbent body and the top sheet, and a method for manufacturing the same. is there.

  In general, absorbent articles such as disposable diapers and urine pads are composed of an absorbent body, a top sheet at least partially made of a liquid-permeable material, and arranged to cover the surface of the absorbent body, and a liquid-impermeable material. And a back sheet disposed so as to cover the back surface of the absorber.

  Such an absorbent article is used so that the top sheet is in contact with the wearer's skin, and urine excreted by the wearer permeates the liquid-permeable portion of the top sheet and is absorbed and held by the absorbent body. And the excrement is prevented from leaking outside by the liquid-impermeable back sheet disposed on the back side of the absorber.

  By the way, in recent years, in order to improve the wearing feeling of the absorbent article and the appearance at the time of wearing, the thickness of the absorbent body has been reduced. As a method for reducing the thickness of the absorbent body, the ratio of superabsorbent polymer (hereinafter referred to as “SAP”) in the absorbent body is increased, and the ratio of bulky pulp is reduced. Methods have been used to increase the amount of absorption per unit volume of the body.

  However, although SAP has a large absorption amount per unit volume compared to pulp, it has a characteristic that it is inferior in terms of absorption rate. Therefore, an absorbent article has been proposed in which a second sheet (also referred to as “diffusion sheet” or “transfer sheet”) made of a nonwoven fabric sheet or the like is disposed between the absorbent body and the top sheet.

  For example, the sanitary material (refer patent document 1) provided with the 2nd sheet | seat which consists of a nonwoven fabric whose basic weight and average density are a predetermined range, The compression sheet | seat, thickness, the thickness at the time of compression, etc. There have been proposed absorbent articles (see Patent Document 2), absorbent articles (see Patent Document 3) including a second sheet having continuous linear grooves formed on the surface thereof, and the like.

Japanese Patent Laid-Open No. 08-269859 Japanese Patent Laid-Open No. 2005-052186 JP 2006-014880 A

  These sanitary materials, absorbent articles, and the like are intended to form a gap between the top sheet and the absorbent body by the second sheet. According to such a configuration, even when a large amount of urine is excreted at a time, the urine can be temporarily stored in the gap and gradually absorbed by the SAP (storage effect). It can also be expected that the urine excreted and diffused over the entire surface of the absorber (diffusion effect). Therefore, even when the SAP ratio in the absorbent body is increased, there is a possibility that it is possible to avoid a situation where urine is not absorbed in time and urine leaks out from the absorbent article.

  However, the sanitary material described in Patent Document 1 uses a sheet containing pulp fibers as the second sheet, and although the storage effect is relatively high, the diffusion effect is not sufficiently satisfactory. Moreover, although the absorbent article of patent document 2 uses the bulky nonwoven fabric as a 2nd sheet | seat and the storage effect is comparatively high, it was not fully satisfied about the diffusion effect. Furthermore, the absorbent article described in Patent Document 3 crushes the sheet in the thickness direction when forming continuous linear grooves on the second sheet, so that the diffusion effect is relatively high, but the storage effect Was not fully satisfactory.

  In other words, conventional sanitary materials and the like have insufficient either or both of the storage effect and diffusion effect of the second sheet. Therefore, if the SAP ratio in the absorber is increased, urine absorption is not in time, and urine is absorbed. It was not possible to sufficiently avoid the situation of leaking from the property article.

  The present invention provides an absorbent article capable of sufficiently avoiding a situation in which urine is not absorbed in time and urine leaks from the absorbent article even when the SAP ratio in the absorber is increased. It is.

  As a result of intensive studies to solve the problems of the prior art as described above, the inventor alternately formed a plurality of concave grooves and a plurality of ridges on both the front surface side and the back surface side of the second sheet, The present invention has been completed by conceiving that the above problems can be solved by joining the tops of the plurality of ridges to the back surface of the top sheet. Specifically, the present invention provides the following absorbent articles and methods for producing the same.

[1] An absorber, a top sheet that is at least partially made of a liquid-permeable material and arranged to cover the surface of the absorber, and a liquid-impermeable material that covers the back surface of the absorber And a second sheet made of a liquid permeable material and disposed between the absorber and the top sheet, the second sheet having a front side and a back side. In both, a plurality of concave grooves and a plurality of ridges extending from one end to the other end of the sheet are alternately formed, and the second sheet has the plurality of concave grooves and the plurality of ridges absorbable. Arranged between the absorber and the top sheet so as to extend in the front-rear direction of the article, the top portion of the plurality of protrusions of the second sheet formed on the front side is on the back surface of the top sheet. Joined The second sheet and the top sheet are integrated , the second sheet is subjected to a hydrophilic treatment with a surfactant, and the second sheet has a basis weight of 30 g / m ² or less and a load of 2 kPa. in the absorbent article sheet thickness at the time when pressed is Ru der less 0.8 mm.

[2] The second sheet is formed in a corrugated plate shape, a portion between the wave crest and the wave crest forms a concave groove on the front surface side, and a portion between the wave bottom and the wave bottom forms a concave groove on the back surface side. The absorbent article according to [1], wherein the absorbent article is formed.

[3] The second sheet is a non-woven sheet at least a part of which is made of a thermoplastic resin, and the plurality of ridges of the second sheet and the back surface of the top sheet are joined by thermal fusion. The absorbent article as described in [1] or [2].

[4] The [1] to [1], wherein the total joint area between the plurality of protrusions of the second sheet and the back surface of the top sheet is in the range of 5 to 20% by area with respect to the apparent area of the second sheet. 3] The absorbent article according to any one of [3].

  In the absorbent article of the present invention, even when the SAP ratio in the absorber is increased, it is possible to sufficiently avoid the situation where urine is not absorbed in time and urine leaks out of the absorbent article.

  Hereinafter, the best mode for carrying out the absorbent article of the present invention will be specifically described with reference to examples of pants-type disposable diapers and tape-type disposable diapers. However, the present invention broadly encompasses absorbent articles (for example, urine pads and the like) having the invention-specific matters, and is not limited to the following embodiments.

[1] Definitions etc .:
The “pants-type disposable diaper”, for example, joins the corresponding side edges 2a, 6a (2b, 6b) of the front body 2 and the back body 6 like the absorbent article 1A shown in FIGS. 1A to 1C. By this, the one waist periphery opening part 10 and a pair of leg periphery opening part 12 (12a, 12b) shall be formed, and it shall mean the disposable diaper comprised beforehand by the underpants type.

  In addition, the “two-piece type” means an absorbent formed in a pad shape by including an absorbent body 22 between the top sheet 18 and the back sheet 20 as in the absorbent article 1A shown in FIGS. 1A and 1B. And a pants-shaped exterior sheet 16 in which one waist opening 10 and a pair of leg openings 12a and 12b are formed, and the absorbent body 14 is disposed inside the exterior sheet 16. It shall mean a fixed form.

  The “tape-type disposable diaper” includes an absorbent body 22, a top sheet 18, and a back sheet 20 as in the absorbent article 1 </ b> B shown in FIGS. 2A and 2B, and left and right side edges of the back body 6. The disposable diaper further provided with the fastening tape 11 which fixes the front body 2 and the back body 6 arrange | positioned so that it may extend from 6a, 6b shall be meant.

  As shown in FIG. 1A, FIG. 1C and FIG. 1D, the “front body” means a portion (reference numeral 2 in the figure) that covers the abdomen side (front of the body) of the wearer when worn on the wearer. ”Is the part that covers the inseam of the wearer when attached to the wearer (reference numeral 4 in the figure), and“ the back body ”is the back side of the wearer (back of the body) when worn on the wearer. Means a portion (reference numeral 6 in the figure) that covers.

[2] Configuration of the absorbent article of the present invention:
The absorbent article of the present invention includes a second sheet 50A made of a liquid-permeable material and disposed between the absorber 22 and the top sheet 18 as in the absorbent article 1A shown in FIG. 1B. The sheet 50A is formed by alternately forming a plurality of concave grooves 52A and 54A and a plurality of ridges 56A and 58A from one end to the other end of the sheet on both the front surface side and the back surface side. The grooves 52A, 54A and the plurality of ridges 56A, 58A are arranged between the absorbent body 22 and the top sheet 18 so that the ridges 56A, 58A are directed in the front-rear direction of the absorbent article 1A. The top of 58A formed on the front side (projection 56A) is joined to the back surface of top sheet 18 (joint 60A), and second sheet 50A and top sheet 18 are integrated. Is shall.

  As in the present invention, by forming concave grooves on both the front side and the back side, voids are formed on both the front side and the back side of the second sheet, so the storage capacity of the second sheet is improved and worn. Even when a person excretes a large amount of urine at a time, the urine can be temporarily stored in the gap. Therefore, even when the SAP ratio inferior in absorption rate is increased for the purpose of slimming or the like, it is possible to sufficiently avoid the situation where urine is not absorbed in time and urine leaks from the absorbent article.

  In addition, by arranging the second sheet so that the plurality of concave grooves are directed in the front-rear direction of the absorbent article, excreted urine and the like are evenly distributed over the entire surface of the absorbent body, and the absorbent capacity of the absorbent body is wasted. It can be used without.

  Furthermore, the top of the ridge formed on the front surface side of the second sheet is joined to the back surface of the top sheet, and the second sheet and the top sheet are integrated. And unintentionally moving between the absorber and the absorber. Therefore, it is possible to effectively prevent a situation in which the concave groove serving as a liquid passage for urine or the like is displaced from a desired position, or the second sheet is moved to one side in the width direction and the width of each concave groove is narrowed. .

  Moreover, since the urine excreted on the top sheet is promptly guided to the second sheet through the junction between the top sheet and the second sheet, leakage can be reliably prevented. Further, by integrating the top sheet and the second sheet, the sheet strength is improved and the shape retention is improved, so that it is possible to prevent the performance from being deteriorated due to the distortion of the sheet.

[2-1] Second sheet:
The second sheet is a sheet material disposed between the absorber and the top sheet for the purpose of temporarily storing urine or the like and diffusing urine or the like.

[2-1A] Material:
The second sheet is made of a liquid-permeable material because it is necessary to transfer urine and body fluid to the absorber. Therefore, a material similar to the top sheet described later can be used. For example, a nonwoven fabric sheet can be used suitably. Among these, nonwoven fabrics with low bulk such as spunbond, card embossing, spunlace, and SMS can be suitably used. By using a nonwoven fabric having a low bulk, liquid such as urine can easily flow on the sheet surface, and a good diffusion effect can be obtained. “Low bulk” means that the sheet has a basis weight of 30 g / m ² or less and a sheet thickness of 0.8 mm or less when pressed with a load of 2 kPa. Among them, it is preferable to use a sheet having a basis weight of 10 to 20 g / m ² and a thickness of 0.1 to 0.5 mm when pressed with a load of 2 kPa.

  The second sheet is a non-woven sheet at least a part of which is made of a thermoplastic resin, and it is preferable that a plurality of ridges of the second sheet and the back surface of the top sheet are joined by heat fusion. As a bonding method, sticking with an adhesive (hot melt adhesive or the like) is also conceivable. However, joining by heat sealing is preferable because it has the advantage that the texture of the unemployed fabric is not impaired.

  Therefore, in the present invention, the nonwoven fabric sheet such as spunbond, card embossing, spunlace, and SMS may be made of a thermoplastic resin such as polyethylene, polypropylene, polyester (PET, etc.). Note that the method of joining by heat fusion will be described in the section of the manufacturing method.

  Examples of a method for imparting liquid permeability to the second sheet include a hydrophilic treatment with a surfactant as with the top sheet. And it is preferable that the 2nd sheet | seat is comprised with the sheet | seat with low liquid permeability compared with a top sheet. This is because if the liquid permeability is too high, urine that has passed through the top sheet will also pass through the second sheet as it is, and the storage effect and diffusion effect cannot be exhibited.

  The “liquid permeability” referred to here is determined based on the permeation time evaluated by the following method. (1) A sheet to be evaluated is fixed to the cylindrical container so as to close the opening end of the cylindrical container (hollow part inner diameter: 10 cm). (2) 10 ml of physiological saline is dropped on the surface of the sheet at a rate of 7 ml / second. (3) The physiological saline is allowed to naturally fall into the hollow portion of the cylindrical container through the sheet. At this time, the permeation time from the start of dropping until the physiological saline disappears from the sheet surface is measured.

[2-1B] Structure:
As shown in FIG. 1B, the second sheet 50 </ b> A is normally disposed between the back surface of the top sheet 18 and the surface of the absorber 22 so as to cover the absorber 22. Although it is not always necessary to be disposed so as to cover the entire surface of the absorber, it is sufficient that at least 30% by area of the surface of the absorber is covered. However, in order to increase the storage effect and the diffusion effect, it is preferable that the absorber is disposed so as to cover the entire surface (100 area%).

Further, as shown in FIG. 1B, the second sheet 50A has a front side (top sheet 18 side).
Grooves 52A and 54A are formed on both the back surface side and the absorber 22 side.

  The second sheet 50A has a plurality of recessed grooves 52A and 54A formed from one end of the sheet to the other end. The concave groove only needs to be directed from one end to the other end, and does not necessarily have to be formed in the entire area between both end portions. It is sufficient to cover at least 40% of the central part in the front-rear direction. “Plurality” means 2 or more, and preferably 4 or more grooves are formed.

  Further, as shown in FIGS. 1B and 3A, the second sheet 50A is formed in a corrugated plate shape, and a portion between the wave crest t1 and the wave crest t2 forms a concave groove 52A on the surface side, and the wave bottom b1 It is preferable that a portion between the wave bottom b2 forms a concave groove 54A on the back surface side. By making it corrugated, a space (concave groove) having a continuous and large cross-sectional area in which liquid such as urine can diffuse between the second sheet and the top sheet and between the second sheet and the absorber. Can be formed. In addition, the sheet is not crushed to form a concave groove, and the sheet is deformed without being crushed to be corrugated, so that the liquid permeability of the sheet is not lowered. On the other hand, when the groove is simply formed by embossing, the groove remains within the sheet thickness range and only a groove having a small cross-sectional area can be formed. Moreover, since a sheet | seat is crushed by embossing, there exists a possibility that the liquid permeability of the bottom part of a ditch | groove may fall.

  In addition, the “corrugated plate shape” referred to in the present specification includes not only the second sheets 50A and 50B having curvilinear undulations as shown in FIGS. 3A and 3B, but also undulations in a polygonal line shape as shown in FIG. 3C. The second sheet 50C is also included. The second sheets 50A and 50B shown in FIGS. 3A and 3B are provided with concave grooves 52A, 54A, 52B, and 54B and convex stripes 56A, 58A, 56B, and 58B having a cross-sectional mountain shape, and the second sheet shown in FIG. 3C. 50C is formed with concave grooves 52C and 54C and convex stripes 56C and 58C having a trapezoidal cross section.

  The second sheet is preferably a corrugated sheet formed by pressing and pressing a nonwoven fabric sheet between a convex portion and a concave portion of a pair of rolls. Such a second sheet has an advantage of excellent shape stability. Further, with such a processing method, a second sheet formed into a corrugated plate having a desired shape can be easily obtained. Furthermore, such processing methods can be easily incorporated into the continuous manufacturing process of absorbent articles. That is, after a sheet once formed in a corrugated form in a separate process is wound into a roll, it is easier to maintain the corrugated form than used in the next process, and deformation of the corrugated form once formed can be prevented. .

  As shown in FIG. 3A, the second sheet 50A is preferably formed in a corrugated plate shape having a wave height h1 of 5 to 30 times the sheet thickness. By setting it to 5 times or more, the second sheet is excellent in storage effect and diffusion effect. If it is 30 times or less, it is possible to prevent a problem that the wave height is too high, the corrugated wave shape is inclined, and the space volume of the groove is reduced.

[2-1C] Joining of second sheet and top sheet:
In this invention, as shown to FIG. 4A and FIG. 4B, FIG. 5A, and FIG. The second sheets 50D and 50E are integrated with the top sheets 18A and 18B.

  The joining method is not particularly limited. For example, adhesion using an adhesive (hot melt adhesive or the like), joining by heat fusion (heat sealing or the like), and the like can be given. Especially, joining by heat fusion is preferable at the point that the texture of unemployed cloth is not spoiled.

  As shown in FIGS. 4A and 4B, the tops of the plurality of ridges may be joined to the back surface of the top sheet in a continuous line shape (joint part 60B), or FIGS. 5A and 5B. As shown in FIG. 4, the tops of the plurality of ridges may be joined to the back surface of the top sheet in an intermittent line shape (joint part 60C). When joined in a continuous line, the effect of promoting diffusion of urine and the like in the front-rear direction of the absorbent article is obtained. When joined in an intermittent line, compared to the case of joining in a continuous line Thus, an effect of facilitating diffusion of urine or the like in the width direction of the absorbent article can be obtained.

  In this invention, it is preferable that the total joining area of the said several protruding item | line of the said 2nd sheet | seat and the back surface of the said top sheet exists in the range of 5-20 area% with respect to the apparent area of the said 2nd sheet | seat.

  By setting the total bonding area to 5 area% or more, the second sheet and the top sheet can be sufficiently bonded, and an effect of inducing urine or the like to the second sheet can be obtained. In addition, since the sheet strength is improved and the shape retention is improved, an effect of preventing the sheet from warping can be obtained. On the other hand, by setting it as 20 area% or less, the space volume of a ditch | groove can be ensured and the storage / diffusion effect of a 2nd sheet | seat can be exhibited effectively. Further, the texture of the sheet can be maintained.

  The “apparent area” means an area calculated when the second sheet is viewed from directly above and regarded as a flat surface having no concave and convex portions due to concave grooves and ridges. For example, when the second sheet is processed into a corrugated plate, the dimension in the direction orthogonal to the groove is shorter after processing than before processing, and the apparent area is reduced.

  As mentioned above, although the absorbent article of this invention has been demonstrated by the example of a pants-type disposable diaper like the absorbent article 1A shown to FIG. 1A-FIG. 1D, this invention is an absorbent article shown to FIG. 2A and FIG. 2B. It can be similarly applied to a tape-type disposable diaper such as 1B.

  That is, the absorbent article 1B shown in FIGS. 2A and 2B includes a second sheet 50A made of a liquid-permeable material and disposed between the absorber 22 and the top sheet 18, and the second sheet 50A includes the second sheet 50A. A plurality of grooves 52A, 54A and a plurality of ridges 56A, 58A from one end to the other end of the sheet are alternately formed on both the front surface side and the back surface side, and a plurality of groove grooves 52A, 54A are formed. And the plurality of ridges 56A, 58A are arranged between the absorbent body 22 and the top sheet 18 so that the ridges 56A, 58A are directed in the front-rear direction of the absorbent article 1A, and the surface side of the plurality of ridges 56A, 58A of the second sheet 50A The top portion of the protrusion (projection 56A) is joined to the back surface of the top sheet 18 (joint portion 60A), and the second sheet 50A and the top sheet 18 are integrated. .

[3] Components of the absorbent article:
The absorbent article of the present invention is arranged such that the absorbent body 22 and at least a part thereof are made of a liquid-permeable material and cover the surface of the absorbent body 22 as in the absorbent article 1A shown in FIGS. 1A to 1D. The top sheet 18 is made of a liquid-impermeable material, and the back sheet 20 is disposed so as to cover the back surface of the absorber 22.

[3-1] Absorber:
The “absorber” is a member for absorbing and holding the wearer's urine and the like, and is made of an absorbent material.

  Examples of the “absorbent material” include fluff pulp, super absorbent polymer (hereinafter referred to as “SAP”), a hydrophilic sheet, and the like. “Fluff pulp” is made by pulverizing wood pulp or non-wood pulp into cotton, “SAP” is sodium polyacrylate, “Hydrophilic sheet” is tissue, absorbent paper, hydrophilized It is preferable to use a non-woven fabric that has been treated.

  As the absorber, it is preferable to use one or two or more absorbent materials formed into a single-layer or multi-layer mat. Especially, what combined 10-500 mass parts SAP with respect to 100 mass parts of fluff pulp is preferable. Especially, the effect of this invention is exhibited when the absorber with a high SAP ratio which used 40-80 mass parts SAP together with respect to 100 mass parts of fluff pulp is used. At this time, the SAP may be mixed in the fluff pulp mat or used in a layered manner between the fluff pulp mats.

  The absorber can be used after being molded into a desired shape such as a rectangular shape, an hourglass shape, a gourd shape, or a T-shape. The absorber is preferably encapsulated with a hydrophilic sheet for the purpose of preventing SAP from falling off and imparting shape stability. Usually, the absorber is sandwiched between a top sheet and a back sheet, and used in a state of being integrated with both sheets.

[3-2] Top sheet:
Since the top sheet needs to allow the wearer's urine or the like to pass therethrough, at least a part (all or a part) of the top sheet is made of a liquid-permeable material.

  Examples of the “liquid permeable material” include woven fabric, non-woven fabric, and porous film. Among these, it is preferable to use a nonwoven fabric made of a thermoplastic resin such as polypropylene, polyethylene, polyester, aliphatic polyamide, etc., which has been subjected to a hydrophilic treatment.

  As the “nonwoven fabric”, a nonwoven fabric produced by a production method such as air through (card hot air) or card embossing can be suitably used. The “hydrophilic treatment” can be performed by applying, spraying, impregnating, etc. a surfactant.

  The top sheet is preferably “at least partly”, more specifically, when the top sheet is viewed in plan, at least the vicinity of the surface of the absorber is made of a liquid-permeable material.

  In addition, the sheet | seat located in the wearer's skin side of an absorbent article does not need to be comprised with all the top sheets. That is, the sheet in contact with the wearer's skin may be constituted by a plurality of sheets including the top sheet, and the top sheet and other sheets may be joined together in the surface direction of the sheet.

  For example, the absorbent article 1B shown in FIGS. 2A and 2B is a tape-type disposable diaper. A topsheet 18 made of a liquid-permeable material is disposed at the center in the width direction of the diaper, and the side flap 9 portion of the diaper is disposed. Is an example in which a side sheet 19 made of a breathable water-repellent material exhibiting resistance to liquid permeation is disposed. The ventilated water-repellent sheet may be a non-woven fabric produced by a method such as card embossing or spunbond, but a non-woven fabric sheet such as SMS or SMMS having a high waterproof property is more preferable.

[3-3] Backsheet:
A backsheet is a sheet | seat arrange | positioned so that the back surface (surface located in the side far from a wearer's skin at the time of mounting | wearing of a diaper) may be coat | covered. The back sheet is made of a liquid-impermeable material because it is necessary to prevent the wearer's urine from leaking outside the diaper.

  There is no restriction | limiting in particular about the arrangement position of a back seat | sheet. From the viewpoint of preventing leakage of urine absorbed by the absorber, it is preferable that a back sheet is disposed at least in a portion where the absorber exists.

  Examples of the liquid-impermeable material constituting the backsheet include a liquid-impermeable film made of a resin such as polyethylene. Among these, a microporous polyethylene film is preferably used. This microporous polyethylene film has a large number of fine pores of 0.1 to several μm, and is liquid impervious but has moisture permeability, so that the inside of the diaper can be prevented from being steamed There is.

  2B, a cover sheet 24 may be bonded to the outer surface side of the back sheet 20. This cover sheet is used to reinforce the back sheet and improve the feel (tactile feeling) of the back sheet.

  Examples of the material constituting the cover sheet include woven fabric and non-woven fabric. Especially, it is preferable to use the dry nonwoven fabric and wet nonwoven fabric which consist of thermoplastic resins, such as polyethylene, a polypropylene, and polyester.

[3-4] Solid gathering:
The absorbent article of the present invention is preferably made of a water-repellent sheet and includes at least a pair of three-dimensional gathers arranged on both sides of the absorbent body.

  The structure of a three-dimensional gather can employ | adopt the structure used for the conventional disposable diaper and other absorbent articles. For example, like the absorbent article 1A shown in FIG. 1B and the absorbent article 1B shown in FIG. 2B, an elastic material (three-dimensional gather elastic material 36) is sandwiched and fixed between layers of the water-repellent sheet 32, and the three-dimensional gather elastic material is obtained. A material in which a gather is formed by a contraction force of 36 can be suitably used. In these examples, the three-dimensional gather stretchable material 36 is sandwiched and fixed to the folded portion of the water-repellent sheet 32.

  The three-dimensional gather may be separately provided with a water-repellent sheet for three-dimensional gather as described above, or may be formed by a part of the sheet material constituting the diaper. For example, the absorbent article 1 </ b> B illustrated in FIG. 2B is an example in which the three-dimensional gathers 26 a and 26 b are formed by a part of the water-repellent sheet 32 constituting the side sheet 19. The water-repellent sheet may be a nonwoven fabric produced by a production method such as card embossing or spunbonding, but a nonwoven fabric sheet such as SMS or SMMS having a high waterproof property is more preferable.

[3-5] Fastening tape:
The absorbent article of the present invention is for fixing the front body 2 and the back body 6 arranged so as to extend from the left and right side edges 6a, 6b of the back body 6, as shown in FIG. 2A. A fastening tape 11 may be provided. That is, the absorbent article of the present invention includes so-called tape-type disposable diapers.

The fastening member of the fastening tape may be an adhesive fastener that is fixed by an adhesive, but a mechanical fastener that is fixed by mechanical coupling (surface fastener).
Is preferably used. In addition to high fastening force, the mechanical fastener has an advantage that the fastening force does not decrease even when the detachment is performed a plurality of times.

  For example, the absorbent article 1B shown in FIG. 2A is an example in which a mechanical fastener 46 is used as a fastening member. A hook material 46 a is attached near the tip of the fastening tape 11, while a front patch 13 made of a loop material 46 b is attached to the front body 2, and the fastening tape 11 is attached to the front patch 13. It is comprised so that it can stop.

  The number of fastening tapes is not particularly limited, and an appropriate number of fastening tapes may be attached according to the dimensions of the wearer's body shape (specifically, around the waist, around the legs, etc.). In general, a pair of disposable diapers for infants (one each on the left and right) is attached, and a pair of disposable diapers for adults (two on the left and two on the left) are attached.

[3-6] Various elastic materials:
When the absorbent article of the present invention is a disposable diaper, it is preferable to dispose a leg elastic member and a waist elastic material.

  The leg circumference elastic material is an elastic material arranged along the leg circumference opening. By arranging the leg-stretchable material, a gather (leg gather) rich in stretchability can be formed in the leg-surrounding opening. Therefore, it is difficult to form a gap around the leg, and urine leakage from the opening around the leg can be effectively prevented.

  For example, the absorbent article 1A shown in FIG. 1A is an underpants-type disposable diaper, and is an example in which leg gathers are formed by arranging leg elastic members 40 along a curve of the leg opening 12 of the diaper. . On the other hand, the absorbent article 1B shown in FIG. 2A is a tape-type disposable diaper, and is an example in which leg gathers are formed by arranging three leg-around elastic members 40 linearly along the longitudinal direction of the diaper. The leg-surrounding elastic member 40 is made of thread rubber or flat rubber.

  The leg stretchable material is preferably formed with a leg stretchable material 40 at a portion outside the standing line of the three-dimensional gather 26, for example, as in the absorbent article 1B shown in FIG. 2A. With such a configuration, it is possible to improve the wearing feeling and wearing feeling of the crotch part while ensuring a sufficient leakage preventing effect of the three-dimensional gather.

  The waist elastic material is an elastic material arranged along the waist opening. By arranging the elastic material around the waist, a gather (waist gather) rich in elasticity can be formed in the waist opening. This waist gather makes it difficult for gaps to be formed around the waist, preventing urine leakage from around the waist, and improving the fit of the diaper to the wearer, thereby preventing the diaper from falling down.

  For example, the absorbent article 1A shown in FIGS. 1A and 1B is an example in which a plurality of waist elastic members 42 are arranged along the opening end of the waist opening 10 of the diaper.

  On the other hand, the absorbent article 1B shown in FIG. 2A is an example in which a band-shaped waist-circular stretchable material 42 is disposed along the edge of the back body 6 of the diaper. The belt-like waist elastic member 42 is made of an elastic foam such as urethane foam. In the illustrated example, the waist elastic member 42 is disposed only on the back body (back side), but the waist elastic material may be disposed on the front body (abdominal side).

  An abdominal circumference elastic material is an elastic material arrange | positioned in the part (namely, part equivalent to a wearer's abdominal circumference) between a waist circumference opening part and a leg circumference opening part. By arranging the elastic material around the abdomen, it is possible to form a highly elastic tammy gather around the abdomen of the wearer. This Tammy Gather, together with West Gather, can make the diaper fit and anti-slip effect even better.

  Absorbent article 1A shown in FIG. 1B surrounds the circumference of the wearer's abdomen in a portion between waist opening 10 and leg opening 12 (that is, a portion corresponding to the wearer's abdomen). This is an example in which a plurality of belly elastic members 44 are arranged.

  For these stretchable materials, after considering the degree of shrinkage of gathers, etc., the constituent material, the elongation rate of the material, the stretched state at the time of fixing, etc. may be determined.

  As an elastic material, the elastic material which has been used with the conventional disposable diaper can be used conveniently. Specific examples include elastic rubber, elastic film, elastic foam (urethane foam, etc.), etc. in addition to natural rubber flat rubber and synthetic rubber (urethane rubber, etc.) elastic thread. it can.

  The stretchable material is preferably fixed in the stretched state in order to exert a sufficient stretch force. For example, when the elastic material is a flat rubber made of natural rubber or a thread rubber made of an elastic thread of synthetic rubber, it is preferably fixed in an extended state of 120 to 400%, and fixed in an extended state of 200 to 300%. More preferably. By fixing in the extended state in such a range, it is possible to apply a sufficient expansion / contraction force without applying an excessive tightening force to the wearer.

  The stretchable material as described above is fixed to other constituent members of the diaper by an adhesive or other means. The fixing method may be, for example, adhesion using a hot melt adhesive or other highly fluid adhesive, or may be welding by heat such as heat sealing or ultrasonic waves.

[3-7] Application target:
In addition, the absorbent article of this invention is applicable also to urine pads other than disposable diapers, such as a pants-type disposable diaper and a tape-type disposable diaper.

  The “urine pad” is also referred to as an inner pad or an auxiliary pad, and is an absorption pad exclusively for urine absorption. This urine pad is used in a state of being placed on the inner surface of the underwear or the surface of the top sheet of the disposable diaper. Like a disposable diaper, the urine pad includes an absorbent body, a top sheet disposed so as to cover the surface of the absorbent body, and a back sheet disposed so as to cover the back surface of the absorbent body. Generally, it is configured in a small pad shape that does not have a portion that encloses a person's waist.

[4] Manufacturing method:
The absorbent article of this invention can be manufactured by the manufacturing method shown in FIG. 6, for example. The manufacturing method of the present invention includes a corrugated step for corrugating the second sheet material, a joining step for joining the second sheet material and the top sheet material, and an absorber composed of the back sheet material and the second sheet-top sheet assembly. And a sealing step of sandwiching and sealing. Hereinafter, it demonstrates for every process.

[4-1] Corrugated plate forming step:
As the second sheet material to be used as the second sheet material, a non-woven sheet made of a liquid-permeable material and at least a part of which is made of a thermoplastic resin is used. In the production method of the present invention, since the second sheet material and the top sheet material are joined by heat fusion, it is necessary to use a nonwoven fabric sheet containing a thermoplastic resin as the second sheet material.

  As shown in FIG. 6, the second sheet material 70 is sandwiched and pressed between a convex roll 72 having a convex portion formed on the surface thereof and a concave roll 74 having a concave portion formed on the surface thereof. Thus, the corrugated second sheet material 76 in which a plurality of concave grooves and a plurality of ridges from one end to the other end of the sheet are alternately formed is formed on both the front surface side and the back surface side.

[4-2] Joining process:
Next, as shown in FIG. 6, the corrugated second sheet material 76 is superposed on the top sheet material 78 at least partly made of a liquid permeable material, and the concave roll 74 and the surface thereof are not uneven. It is sandwiched between the plain rolls 80 and pressed while heating the plain rolls 80. In the illustrated example, the corrugated second sheet material 76 and the top sheet material 78 are sandwiched between the concave roll 74 and the plain roll 80, but the positions of the concave roll 74 and the convex roll 72 in the figure are switched. The corrugated second sheet material 76 and the top sheet material 78 may be sandwiched between the convex roll 72 and the plain roll 80.

  As a result, among the plurality of ridges of the corrugated second sheet material 76, the top portion of the one formed on the front surface side is joined to the back surface of the top sheet material 78, and the corrugated second sheet material 76 and the top sheet material 78 are joined. And a second sheet-top sheet assembly 82 in which are integrated with each other.

[4-3] Sealing step:
Finally, an absorbent body is placed on a back sheet material made of a liquid-impermeable material, and a second sheet-top sheet assembly is placed on the back sheet material on which the absorbent body is placed and absorbed. At the periphery of the body, the back sheet material and the second sheet-top sheet assembly are joined, and the absorbent body is sandwiched between the back sheet material and the second sheet-top sheet assembly and sealed. Thereby, as shown in FIG. 1B or FIG. 2B, the absorber 22, the top sheet 18 disposed so as to cover the surface of the absorber 22, and the back disposed so as to cover the back surface of the absorber 22. The basic structure of the absorbent article with the sheet 20 is formed. About another part, it can manufacture according to manufacture of a conventionally well-known absorbent article.

  The absorbent article of the present invention will be described more specifically with reference to the drawings. However, the absorbent article of the present invention encompasses all absorbent articles having the invention-specific matters, and is not limited to the following examples.

[Example 1]
As an absorbent article of Example 1, a pants-type disposable diaper was produced. The specific structure was the structure of the absorbent article 1A shown in FIGS. 1A to 1D. This absorbent article 1A is of L size for babies, the length in the front-rear direction is 500 mm, and the width of the back body 6 (the length between the side edges 6a and 6b) is 390 mm.

The second sheet was constituted by a spunbond nonwoven fabric sheet having a basis weight of 20 g / m ² . This spunbond nonwoven fabric was a nonwoven fabric sheet made of thermoplastic polypropylene. The spunbonded nonwoven fabric was hydrophilized by a surfactant treatment to obtain a liquid-permeable sheet. The liquid permeation time of this second sheet measured by the above-mentioned method is 7 seconds, and compared with the top sheet (air-through nonwoven fabric sheet having a basis weight of 25 g / m ² ) which has a liquid permeation time of 3 seconds by the same measurement method. Thus, the liquid permeability was lowered. The liquid permeability of the second sheet and the top sheet was adjusted by the coating amount of the surfactant and the sheet density.

The second sheet was formed in a corrugated plate shape shown in FIG. 3A. Specifically, it was performed by the method shown in FIG. Using a spunbonded non-woven sheet having a basis weight of 20 g / m ² (width 150 mm × length 400 mm × thickness 0.25 mm) as the second sheet material 70, a convex roll 72 having a convex portion formed on its surface, and a surface thereof It is sandwiched and pressed between the concave roll 74 in which the concave portion is formed. Thus, the corrugated second sheet material 76 in which a plurality of concave grooves and a plurality of ridges from one end to the other end of the sheet were alternately formed was formed on both the front surface side and the back surface side.

  A curved waviness as shown in FIG. 3A is formed from the corrugated second sheet material 76, and a portion between the wave crest t1 and the wave crest t2 forms a concave groove 52A on the surface side (top sheet side). A corrugated second sheet 50A in which a portion between the wave bottom b1 and the wave bottom b2 forms a concave groove 54A on the back surface side (absorber side) can be obtained.

  In the second sheet, six grooves on the front surface side and seven grooves on the back surface side from one end to the other end of the sheet were formed. This concave groove was formed in the whole area between both ends from one end to the other end. This second sheet had a crest interval W1 of 15 mm and a wave height h1 of 6 mm. That is, the wave height h1 is 6 mm (24 times) with respect to the sheet thickness of 0.25 mm.

  Next, as shown in FIG. 6, the corrugated second sheet material 76 formed as described above is overlapped with a top sheet material 78 at least partially made of a liquid permeable material, and the concave roll 74 and its surface And the plain roll 80 was pressed while being heated at 145 ° C.

As a result, among the plurality of ridges of the corrugated second sheet material 76, the top portion of the one formed on the front surface side is joined to the back surface of the top sheet material 78, and the corrugated second sheet material 76 and the top sheet material 78 are joined. And a second sheet-top sheet joined body 82 integrated with each other. In this case, the total bonding area between the plurality of projections and the rear surface of the top sheet of the second sheet is 4200 mm ^2, was 10 area% relative to the apparent area 42000Mm ² of the second sheet.

  Finally, an absorbent body is placed on a back sheet material made of a liquid-impermeable material, and a second sheet-top sheet assembly is placed on the back sheet material on which the absorbent body is placed and absorbed. At the periphery of the body, the back sheet material and the second sheet-top sheet assembly were joined, and the absorbent body was sandwiched between the back sheet material and the second sheet-top sheet assembly and sealed. Thereby, as shown in FIG. 1B, the absorbent body 22, the top sheet 18 disposed so as to cover the surface of the absorbent body 22, and the back sheet 20 disposed so as to cover the back surface of the absorbent body 22. The basic structure of the absorbent article was formed. About the other part, it manufactured according to manufacture of a conventionally well-known absorbent article.

  The absorbent article of the present invention can be used for absorbent articles such as disposable diapers and urine pads for infants or adults such as the elderly and persons with disabilities who need care. In particular, it can be suitably used for an absorbent article having an increased SAP ratio for the purpose of slimming.

It is a schematic plan view which shows the state which expand | deployed the absorbent article of this invention and was seen from the top sheet side. It is a schematic sectional drawing which shows the X-X 'cross section of the absorbent article shown to FIG. 1A. It is a schematic perspective view which shows the state which assembled the absorbent article shown to FIG. 1A and was seen from the front side. It is a schematic plan view which removes an absorptive main body from the absorptive article shown in Drawing 1A, and shows only a portion of an exterior sheet. It is a schematic plan view which shows another embodiment of the absorbent article of this invention, is a figure which shows the state which expand | deployed the absorbent article and was seen from the top sheet side. It is a schematic sectional drawing which shows the A-A 'cross section of the absorbent article shown to FIG. 2A. It is a schematic sectional drawing which shows one Embodiment of the 2nd sheet | seat used for the absorbent article of this invention. It is a schematic sectional drawing which shows another embodiment of the 2nd sheet | seat used for the absorbent article of this invention. It is a schematic sectional drawing which shows another embodiment of the second sheet used for the absorbent article of this invention. It is a schematic plan view which shows one Embodiment of joining of a 2nd sheet | seat and a top sheet, and is a figure which shows the state seen from the 2nd sheet | seat side. It is a schematic sectional drawing which shows the X-X 'cross section of the absorbent article shown to FIG. 4A. It is a schematic plan view which shows another embodiment of joining of a 2nd sheet | seat and a top sheet, and is a figure which shows the state seen from the 2nd sheet | seat side. It is a schematic sectional drawing which shows the X-X 'cross section of the absorbent article shown to FIG. 5A. It is a schematic side view which shows one Embodiment of the manufacturing method of the absorbent article of this invention.

Explanation of symbols

1A, 1B: Absorbent article, 2: Front body, 2a, 2b: Side edge, 4: Crotch, 6: Rear body, 6a, 6b: Side edge, 8: Joint, 9: Side flap, 10: Waist Surrounding opening, 11: Fastening tape, 12, 12a, 12b: Leg opening, 13: Front patch, 14: Absorbent body, 16: Exterior sheet, 18, 18A, 18B: Top sheet, 19: Side sheet 20: Back sheet, 22: Absorber, 24: Cover sheet, 26, 26a, 26b: Three-dimensional gather, 32: Water-repellent sheet, 36: Three-dimensional gather stretchable material, 40: Stretch material around leg, 42: Stretch around waist Material: 44: Stretch material around the stomach, 46: Mechanical fastener, 46a: Hook material, 46b: Loop material, 50A, 50B, 50C, 50D, 50E: Second sheet, 52A, 52B, 52C Concave groove (front side), 54A, 54B, 54C: Concave groove (back surface side), 56A, 56B, 58A, 58B: Convex strip, 60A, 60B, 60C: Joining part, 70: Second sheet material, 72: Convex roll 74: concave roll, 76: corrugated second sheet material, 78: top sheet material, 80: plain roll, 82: second sheet-top sheet assembly, t1, t2: wave top, b1, b2: wave bottom, h1, h2, h3: wave height, W1, W2, W3: wave crest interval.

Claims (4)

An absorber, at least partly made of a liquid-permeable material, a top sheet arranged to cover the surface of the absorber, and a liquid-impermeable material so as to cover the back surface of the absorber A back sheet disposed, and a second sheet made of a liquid permeable material and disposed between the absorber and the top sheet,
The second sheet is formed by alternately forming a plurality of concave grooves and a plurality of ridges from one end to the other end of the sheet on both the front side and the back side.
The second sheet is disposed between the absorber and the top sheet such that the plurality of concave grooves and the plurality of ridges are directed in the front-rear direction of the absorbent article,
The top of what is formed on the front side of the plurality of ridges of the second sheet is joined to the back surface of the top sheet, and the second sheet and the top sheet are integrated ,
The second sheet has been subjected to a hydrophilic treatment with a surfactant,
The second sheet has a basis weight of 30 g / ^{m 2} or less, the absorbent article sheet thickness at the time when pressed with a load 2kPa is Ru der less 0.8 mm.   The second sheet is formed in a corrugated plate shape, a portion between the wave crest and the wave crest forms a concave groove on the front side, and a portion between the wave bottom and the wave bottom forms a concave groove on the back surface side. The absorbent article according to claim 1. The second sheet is a non-woven sheet at least part of which is made of a thermoplastic resin,
The absorbent article according to claim 1 or 2, wherein the plurality of protrusions of the second sheet and the back surface of the top sheet are joined by heat fusion.   The total joint area of the plurality of ridges of the second sheet and the back surface of the top sheet is in the range of 5 to 20 area% with respect to the apparent area of the second sheet. Absorbent article according to item.

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