JP5053608B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article such as a disposable paper diaper, a sanitary napkin, and an absorbent pad, and more particularly to an absorbent article capable of suppressing liquid flow and body fluid diffusion in the longitudinal direction of the absorbent article.

  As absorbent articles, such as a disposable diaper and a sanitary napkin, the thing which interposed the absorber between the liquid-permeable surface sheet and the liquid-impermeable back sheet is known. In this type of absorbent article, in order to satisfy the dry touch feeling on the skin and to increase the absorption rate of body fluid, as the liquid-permeable surface sheet, a hydrophilic nonwoven fabric or a porous sheet (so-called mesh sheet) is used, There is one in which a hydrophilic sheet called a second sheet is interposed between the liquid-permeable surface sheet and the absorber.

  For example, in Patent Document 1 below, an absorbent unit made of an absorbent body and crepe paper surrounding the absorbent body, a liquid-permeable surface sheet that covers the surface side of the absorbent unit, and a back sheet that covers the back side of the absorbent unit In the disposable paper diaper, the absorption unit contributes to absorption of body fluids such as urine and stool made of an absorber and crepe paper surrounding the absorber, specifically, upper crepe paper and lower crepe paper. A semi-rigid property that can be deformed as a whole, and a liquid-permeable second sheet is disposed on the upper surface of the absorption unit so as to cover the central area. A structure is disclosed in which a liquid-permeable surface sheet is fixed to a top surface of a second sheet by a hot melt adhesive so as to cover almost the entire surface of the absorption unit (paragraph [00 22]).

Moreover, in the following Patent Documents 2 to 4, etc., a hydrophilic sheet called a second sheet is interposed between the liquid-permeable surface sheet and the absorber, and the mesh sheet and the second sheet are not formed by a predetermined emboss pattern. A continuous joint has been proposed.
JP 2002-84552 A JP-A-7-328060 JP-A-8-117277 JP-A-10-272152

  However, the hydrophilic second sheet is arranged so that the sheet is drawn out in the production line direction and arranged on the absorbent body. However, the sheet having the fibers oriented along the line direction is required because of the need to have tensile strength in the line direction. It is used. Generally, the fiber orientation ratio in the absorber major axis direction (hereinafter also referred to as longitudinal direction or longitudinal direction): absorber minor axis direction (hereinafter also referred to as lateral direction or transversal direction) is 95: 5 to 80:20. Usually it is about.

  Therefore, the discharged urine is easy to diffuse in the vertical direction, and the body fluid is transferred to the absorber with little diffusion in the lateral direction, resulting in a large amount of body fluid concentrating on a part of the absorber. Despite the body fluid accommodation capacity in the direction, the body fluid accommodation capacity in the vertical direction exceeded the limit point, and leakage sometimes occurred from the front and rear ends of the product. Conventionally, in order to suppress such diffusion in the vertical direction, the sheet is bulky or the weight per unit area is increased to improve the liquid-absorbing ability. Although the body fluid is difficult to flow in the vertical direction by processing such as improvement, it has not yet reached a fundamental solution.

  In recent years, an absorbent body in which continuous fibers (acetate fibers) oriented in the longitudinal direction are mixed in the absorbent body has been provided. In such an absorbent body, the fibers are oriented almost 100% in the longitudinal direction. Therefore, since the body fluid easily diffuses in the longitudinal direction, the body fluid cannot be stored in the absorbent body for a time required for the polymer to absorb the body fluid, and leakage may occur from the front and rear ends of the product.

Therefore a main object of the present invention, between the liquid-permeable topsheet and the backsheet, is surrounded by a core wrap sheets Rutotomoni, it is composed of a fluff-like pulp and the absorbent polymers with longitudinally oriented the continuous fibers absorber is interposed a, in absorbent articles the hydrophilic second sheet is interposed between the front KiTorueki topsheet and the absorbent body, prompting the diffusion in the lateral direction, the leakage from the front and rear ends of the product An object of the present invention is to provide an absorbent article that can be prevented.

Orientation as the present invention according to claim 1 to solve the above problem, between the liquid-permeable topsheet and the backsheet, while being surrounded by co Arup sheet, the fluffy pulp and water-absorbing polymer and the longitudinal direction In an absorbent article in which a hydrophilic second sheet is interposed between the liquid-permeable surface sheet and the absorbent body, an absorbent body composed of continuous fibers made is interposed,
A nonwoven fabric having a fiber orientation in one direction is used for at least one of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet, and has a fiber orientation in a substantially short direction of the absorbent article. An absorbent article characterized by being arranged as described above is provided.

In the invention according to the first aspect, at least one of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet is a non-woven fabric having a fiber orientation in one direction. It arrange | positions so that it may have fiber orientation in the substantially transversal direction of articles | goods. Accordingly, since the diffusibility of the absorbent article in the short direction is improved, the flow rate of the body fluid moving in the longitudinal direction is reduced, and leakage from the front and rear ends of the product can be prevented. That is, in the present invention, it is used an absorber mixed with continuous fibers oriented in the longitudinal direction (acetate fiber) in the absorbent body, thereby improving the lateral direction of the diffusion of the absorbent article results in the longitudinal direction It takes time for the liquid to flow, and the body fluid can be stored in the absorbent body for the time required for the polymer to absorb the body fluid. The fiber orientation in one direction means that the fiber orientation ratio in one direction generally exceeds 80%.

Configured as the present invention according to claim 2, from between the liquid-permeable topsheet and the backsheet, while being surrounded by co Arup sheet, a fluffy pulp and the absorbent polymers with longitudinally oriented the continuous fibers In the absorbent article in which a hydrophilic second sheet is interposed between the liquid-permeable surface sheet and the absorbent body, with the interposed absorbent body interposed therebetween,
At least one of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet has a total fiber weight of 50% or more of −45 ° to the short direction of the absorbent article. An absorbent article characterized by being oriented so as to have fiber orientation in a range of + 45 ° is provided.

  In the invention according to the second aspect, at least one of the liquid-permeable surface sheet, the hydrophilic second sheet and the core wrap sheet is 50% or more of the total fiber weight constituting the sheet. The fibers are oriented so as to have fiber orientation in a range of −45 ° to + 45 ° with respect to the hand direction. Therefore, although the degree of effect is lower than that of the first aspect, substantially the same effect can be achieved.

In the first and second aspects of the invention, among the three members of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet, the member having fiber orientation with respect to the short direction of the absorbent article is The hydrophilic second sheet is desirable. As the hydrophilic second sheet, a sheet having an improved liquid transport property in the fiber orientation direction by a fiber configuration, thickness and basis weight is generally used. In particular, in the present invention in which fibers having a very long diffusion in the longitudinal direction such as acetate fibers are used in the absorbent body, the second sheet having excellent liquid transportability is the most effective for supplementing the diffusion in the short direction. The most reliable means is to adjust the orientation of the. Also, in terms of production, it is possible to easily perform production by 90 ° reversal as compared to a top sheet generally joined to a three-dimensional gather (or a waist sheet or the like) or a core wrap enclosing an absorbent.

According to the present invention as detailed above, composed of a core wrap is enclosed by the sheet Rutotomoni, the continuous fibers oriented in fluffy pulp and water-absorbing polymer and longitudinally between the liquid-permeable topsheet and the backsheet is interposed absorption body in an absorbent article with a hydrophilic second sheet is interposed between the front KiTorueki topsheet and the absorbent body, by prompting diffusion of lateral direction, from the front and rear ends of the product It becomes possible to prevent leakage.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Structure example of disposable paper diapers]
FIG. 1 is a partially broken development view of a disposable paper diaper according to the present invention, and FIG. 2 is a transverse sectional view.

  1 and 2, the disposable diaper 1 is made of cotton-like pulp or the like, has a certain degree of rigidity such as an hourglass shape or a rectangular shape, and is surrounded by a core wrap sheet 5 such as a crepe paper or a hydrophilic nonwoven fabric. An absorbent body 4, a liquid-permeable surface sheet 3 made of a perforated or non-porous nonwoven fabric, a perforated plastic sheet, or the like disposed so as to cover the surface side (use side) of the absorbent body 4, and the absorption A leak-proof sheet 6 made of polyethylene or the like disposed on the back side of the body 4 so as to cover at least the entire area of the absorber 4, and an outer surface side (non-skin contact surface side) of the leak-proof sheet 6 ), The outer back sheet 2 that defines the outer shape of the diaper, and the three-dimensional gather BS that stands on the front side on both sides of the paper diaper. Side nonwoven fabrics 7 and 7 for constituting the side flap portion SF together with the leak-proof sheet 6 and the back sheet 2, and a hydrophilic second sheet 11 interposed between the liquid-permeable surface sheet 3 and the absorbent body 4, It is mainly comprised from the mechanical joining type fastening tapes 10 and 10 provided on both sides of the diaper back side. Further, at the abdomen waist portion and the back waist portion of the paper diaper, the outer back sheet 2, the leak-proof sheet 6 and the liquid-permeable surface sheet 3 extend together, and an end flap portion EF where the absorber 4 does not exist is formed. ing.

  In attaching, as shown in FIG. 3, the front and back bodies of the disposable diaper 1 are respectively applied to the wearer's body, and then the fastening tapes 10 and 10 are brought to the ventral side, A paper diaper is mounted in direct engagement with the surface.

In the following, each configuration will be specifically described in detail.
The absorber 4 is composed of, for example, fluffy pulp and a water-absorbing polymer. The water-absorbing polymer is mixed in the pulp constituting the absorber, for example, as granular powder. Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. It is preferably used in terms of price. Further, as described above, an absorbent body in which continuous fibers (acetate fibers) oriented in the longitudinal direction are mixed in the absorbent body can be used, and when this absorbent body is used, the liquid diffusibility in the longitudinal direction is particularly significant. Therefore, by applying the present invention, it is possible to promote diffusion in the short-side direction and prevent leakage before and after.

  Moreover, when the absorber 4 is surrounded by the core wrap sheet 5 as in the illustrated example, the core wrap sheet 5 is interposed between the liquid-permeable surface sheet 3 and the absorber 4 as a result. In addition, the core wrap sheet 5 having excellent absorbability allows the body fluid to be quickly diffused and prevents reversal of these menstrual blood and the like.

  As the liquid-permeable surface sheet 3, a porous or non-porous nonwoven fabric or a porous plastic sheet is preferably used. Examples of the material fibers constituting the nonwoven fabric include synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a lace method, a spun bond method, a thermal bond method, an air through method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and the spunbond method is excellent in drapeability, and the thermal bond method and the air-through method are excellent in terms of being bulky and soft.

  The leak-proof sheet 6 is made of a sheet material having at least a water shielding property such as an olefin resin sheet such as polyethylene or polypropylene, and is installed in a range covering at least the entire area of the absorber 4 in order to prevent leakage. In recent years, those having moisture permeability are preferably used from the viewpoint of preventing stuffiness. This water-impervious / breathable sheet is a microporous sheet obtained by, for example, melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. If the sheet thickness is the same, the rigidity is lower than that of the non-porous sheet, which is superior in terms of flexibility.

  As the side nonwoven fabric 7, a water-repellent treated nonwoven fabric or a hydrophilic treated nonwoven fabric can be used from the viewpoint of an important function. For example, if importance is placed on functions such as preventing permeation of menstrual blood or vaginal discharge, or enhancing the touch feeling, water repellent treatment coated with silicon, paraffin or alkylchromic chloride water repellent It is desirable to use a nonwoven fabric. In addition, if importance is attached to absorbability of body fluids, a method of polymerizing a compound having a hydrophilic group, for example, an oxidation product of polyethylene glycol, in the production process of synthetic fibers, or a metal such as stannic chloride Use a non-woven fabric that has been treated with salt to make the synthetic fiber swelled or porous, such as by partially dissolving the surface to make it porous and depositing metal hydroxide, and applying hydrophilicity by applying capillary action. It is desirable to make it.

  The liquid-permeable surface sheet 3 projects slightly outward from the side edge of the absorber 4 and is joined to the leak-proof sheet 6. The side nonwoven fabric 7 has an outer portion extending to the outer edge rather than the vicinity of the side edge portion of the absorbent body 4 and is joined to the leakage preventing sheet 6 and the outer back sheet 2, and the laminated sheet portion constitutes a side flap SF. Yes.

  In the side flap portion SF, a plurality of elastic elastic members 8 and 8 in the illustrated example are arranged in the longitudinal direction of the paper diaper, and a planar gather is formed. The flat gathers hold the paper diaper tightly around the legs when worn, thereby improving fit and preventing the paper diaper from shifting.

  On the other hand, a three-dimensional gather BS standing on the surface side is formed by the nonwoven fabric sheet portion on the inner side of the fixed portion of the side nonwoven fabric 7. The three-dimensional gather BS has a standing end near the side edge of the absorbent body 4, and the tip thereof is double-folded along the longitudinal direction of the paper diaper. One elastic elastic member 9 is formed inward of the folded portion. If necessary, a plurality of elastic elastic members are provided, and the three-dimensional gather BS is erected using the elastic force.

  As the elastic elastic members 8 and 9, materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicon, polyester and the like that are usually used can be used. .

  The material fibers constituting the side nonwoven fabric 7 can be synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester or polyamide, recycled fibers such as rayon or cupra, and natural fibers such as cotton. The nonwoven fabric obtained by an appropriate processing method such as a spunbond method, an air-through method, a melt blown method, a needle punch method can be used. In particular, the side nonwoven fabric 7 constituting the side flap portion SF has a feeling of wrinkles. In order to eliminate it and to prevent stuffiness, it is preferable to use a non-woven fabric that suppresses the basis weight and has excellent air permeability.

  The mechanical joining type fastening tape 10 has a base of a fastening base material 10A such as plastic, polylaminated nonwoven fabric, nonwoven fabric, paper, etc. joined to a diaper. A hook element 10B is provided on the protruding portion of the fastening substrate 10A and on the surface side (surface on the liquid-permeable surface sheet 3 side). The hook element 10B is bonded to the fastening base material 10A with an adhesive so as not to be peeled off. The hook element 10B has a large number of engaging pieces 10b, 10b,. As the shape of the engagement piece 10b, for example, (A) letter shape, (B) J shape, (C) mushroom shape, (D) T shape, (E) double J shape (J shape) , Etc. exist, but any shape may be used. In the product state, the fastening tape 10 is folded to the liquid-permeable surface sheet 3 side, and the hook element 10B is detachably bonded to the side nonwoven fabric 7.

  Examples of the material fibers constituting the nonwoven fabric of the outer backsheet 2 include synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, an air-through method, or a needle punch method can be used.

[Structure of the second sheet 11]
The hydrophilic second sheet 11 interposed between the liquid-permeable surface sheet 3 and the absorbent body 4 is configured to cover the inner side area of the upper surface of the absorbent body 4. In addition, cellulose fibers such as cotton and rayon, synthetic fibers having hydrophilic groups such as acrylonitrile and polyvinyl alcohol, and hydrophobic fibers such as polyethylene, polypropylene and polyester were surface treated with a hydrophilizing agent to impart hydrophilicity. Fiber or the like is used. The hydrophilic second sheet 11 may extend beyond the edge of the absorbent body 4 to the side edge of the liquid-permeable surface sheet 3. In particular, when the hydrophilic second sheet 11 is extended to the side of the absorber 4, the water of excreta accumulated in the pocket formed between the absorber 4 and the three-dimensional gather BS is transferred to the absorber 4. The effect of being easy is born. Further, when the hydrophilic second sheet 11 is extended in the front-rear direction of the absorbent body 4, the end flap EF becomes stiff and the fitting property at the time of wearing is improved.

  In the present invention, as the hydrophilic second sheet 11, a nonwoven fabric having a fiber orientation in one direction is used. Nonwoven fabrics generally have a classification based on the fiber orientation state in the web in addition to the classification based on the web forming method and the web adhesion method. Among these, the parallel web in which the fibers are oriented in one direction, the cross web in which the fibers are orthogonal to each other, and the random web in which the orientation of the fibers is random are used.

  And the said hydrophilic second sheet | seat 11 is arrange | positioned so that the fiber oriented in one direction may have fiber orientation in the substantially transversal direction (X direction) of a diaper.

  In order to arrange the hydrophilic second sheet 11, as shown in FIG. 4, in the process of transporting the absorbent bodies 4, 4... With the production line direction as a longitudinal dimension (Y dimension shown in FIG. 1), the hydrophilic second sheet 11 is disposed. The sex second sheet 11 is supplied along the production line in a state having fiber orientation, and is cut into a predetermined length. In the transported state after cutting, the dimension in the line direction of the hydrophilic second sheet 11 is the short dimension (X direction) shown in FIG. 1, and the dimension perpendicular to the line is the long dimension (Y dimension). Has fiber orientation in the direction. The transported hydrophilic second sheet 11 is reversed 90 ° in a plane in the course of being transported on the drum by the 90 ° reversing device 12 and is disposed on the upper surface of the absorber 4.

  By the way, as the hydrophilic second sheet 11, in addition to the parallel web in which the fibers are oriented in one direction, a non-woven fabric or a composite non-woven fabric conforming to the parallel web also exists depending on the degree of fiber direction control in the manufacturing process. Therefore, the fiber direction of the second sheet 11 is such that 50% or more of the total fiber weight constituting the sheet has a fiber orientation in the range of −45 ° to + 45 ° with respect to the short direction of the absorbent article. In general, the desired object of the present invention can be achieved.

[Other examples]
(1) In the above embodiment, the example in which the present invention is applied to the hydrophilic second sheet 11 interposed between the liquid-permeable surface sheet 3 and the absorber 4 has been described. The core wrap sheet 5 can be similarly applied, and at least one of these members uses a non-woven fabric having fiber orientation in one direction, and is arranged so as to have fiber orientation in a substantially short direction of the paper diaper. Alternatively, it may be oriented so that 50% or more of the total fiber weight constituting the sheet has fiber orientation in a range of −45 ° to + 45 ° with respect to the short direction of the absorbent article. Moreover, about the back sheet 2 and the side nonwoven fabric 7 which constitute a paper diaper constituting member, in particular, a side flap SF, and which is easily loaded in the short direction at the time of wearing, a diaper in use has a fiber orientation in the short direction. It is also effective in preventing damage.
(2) The present invention uses a nonwoven fabric having a fiber orientation in one direction for at least one member of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet, and the fibers are arranged in a substantially short direction of the paper diaper. Arrange so as to have orientation, or 50% or more of the total fiber weight constituting the sheet has fiber orientation in the range of −45 ° to + 45 ° with respect to the short direction of the absorbent article Even though the non-woven fabric (cross web) having substantially perpendicular fiber orientation is used as the liquid-permeable surface sheet 3 and the hydrophilic second sheet 11, the liquid in the vertical direction is to some extent. It is possible to suppress diffusion and promote lateral diffusion.
(3) In the above embodiment, the present invention has been described by taking a tape-type disposable paper diaper as an example, but the present invention applies not only to pants-type disposable paper diapers but also to absorbent articles such as sanitary napkins and absorbent pads. It is possible to apply.

It is a partial fracture development view of the disposable paper diaper concerning the present invention. It is the cross-sectional view (II-II arrow directional view). It is a perspective view which shows a mounting state. FIG. 3 is a layout diagram of a hydrophilic second sheet 11.

  DESCRIPTION OF SYMBOLS 1 ... Disposable diaper, 2 ... Outer surface back sheet, 3 ... Liquid-permeable surface sheet, 4 ... Absorber, 5 ... Core wrap sheet, 6 ... Leak-proof sheet, 7 ... Side nonwoven fabric, 10 ... Fastening tape, 11 ... Hydrophilic Second sheet, 12 ... 90 ° reversing device

Claims (2)

Between the liquid-permeable topsheet and the backsheet, while being surrounded by co Arup sheet, with the configuration absorption body is interposed and a fluffy pulp and the absorbent polymers with longitudinally oriented the continuous fibers In an absorbent article in which a hydrophilic second sheet is interposed between the liquid-permeable surface sheet and the absorbent body,
A nonwoven fabric having a fiber orientation in one direction is used for at least one of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet, and has a fiber orientation in a substantially short direction of the absorbent article. An absorbent article characterized by being arranged as described above. Between the liquid-permeable topsheet and the backsheet, while being surrounded by co Arup sheet, with the configuration absorption body is interposed and a fluffy pulp and the absorbent polymers with longitudinally oriented the continuous fibers In an absorbent article in which a hydrophilic second sheet is interposed between the liquid-permeable surface sheet and the absorbent body,
At least one of the liquid-permeable surface sheet, the hydrophilic second sheet, and the core wrap sheet has a total fiber weight of 50% or more of −45 ° to the short direction of the absorbent article. An absorbent article characterized by being oriented so as to have fiber orientation in a range of + 45 °.

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