JP6910253B2 - Absorbent article - Google Patents

Description

The present invention relates to an absorbent article comprising an absorbent core and a core wrap sheet covering the absorbent core.

As an absorbent article such as a disposable diaper, a liquid-permeable front sheet forming a skin-facing surface, a liquid-impermeable back sheet forming a non-skin facing surface, and an absorbent body arranged between both sheets are provided. It is known that the absorbent body is composed of an absorbent core containing an absorbent material such as wood pulp or a water-absorbent polymer, and a core wrap sheet that covers the outer surface of the absorbent core. The core wrap sheet functions as a sheet for receiving the absorbent material at the time of manufacturing the absorbent body, and plays a role of wrapping and shaping the absorbent core after manufacturing. As the core wrap sheet, a water-permeable sheet such as thin paper, absorbent paper, or non-woven fabric has been conventionally used.

Regarding the core wrap sheet, Patent Document 1 states that the skin-side core wrap sheet that covers the skin-facing surface of the absorbent core has a two-layer structure composed of a first layer and a second layer having different liquid permeation velocities. It is stated that doing so improves liquid permeability and liquid diffusivity. Patent Document 1 describes, as an example of a combination of the first layer and the second layer, a combination of a paper made of non-thermoplastic hydrophilic fibers on one side and a non-woven fabric made of thermoplastic fibers on the other side. The distribution state of the constituent fibers (pulp fibers) in the skin-side core wrap sheet is not particularly described.

Patent Document 2 describes a two-layer structure as an absorbent sheet that can be used as an absorbent core, not as a core wrap sheet. The absorbent sheet having a two-layer structure is made of a non-woven fabric that exceeds 42 layers on the skin side. According to the absorbent sheet described in Patent Document 2, the surface is less wettable and the contour formed by the absorbed moisture is difficult to be visually recognized from the outside.

Japanese Unexamined Patent Publication No. 2013-180171 Japanese Unexamined Patent Publication No. 2005-67190

In general, the absorbent core has a long shape in the anterior-posterior direction (longitudinal direction) of the wearer of the absorbent article, whereas the excrement part (penis, vagina) of the wearer in which excrement such as urine and feces is excreted. Since the mouth, anus, etc.) are located in the vertical center of the absorbent core, the site that substantially contributes to the absorption of excrement is limited to the vertical center of the absorbent core and its vicinity. There is a problem that it is difficult to effectively utilize other parts. In this regard, if the skin-side core wrap sheet that covers the skin-facing surface of the absorbent core has excellent liquid diffusivity in the surface direction, the excrement is rapidly diffused in the surface direction and transferred to the absorbent core. This will lead to the solution of such problems. However, if the liquid is diffused in the surface direction by the skin-side core wrap sheet on the side facing the skin, which is relatively close to the wearer's skin, the state becomes close to what is called liquid residue, and the surroundings of the skin become high humidity. It may lead to skin troubles. In addition, the conventional core wrap sheet has room for improvement in terms of preventing so-called liquid return, in which the body fluid once absorbed by the absorbent core is transferred to the wearer's skin side.

Therefore, an object of the present invention is to provide an absorbent article having an excellent wearing feeling, in which liquid residue and liquid return are unlikely to occur at a position close to the wearer's skin.

The present invention has a vertical direction corresponding to a direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the vertical direction, and the crotch portion arranged in the crotch portion and before and after the crotch portion. An absorbent article having an extending ventral and dorsal sides and comprising a liquid-retaining absorbent core and a skin-side core wrap sheet covering the skin-facing surface of the absorbent core. The skin-side core wrap sheet is configured to include a laminated structure of a skin-side layer forming a skin-facing surface and a non-skin-side layer forming a non-skin-facing surface, and the skin-side layer is mainly composed of thermoplastic fibers. The non-skin side layer is mainly composed of non-thermoplastic hydrophilic fibers, and a plurality of compacted portions that are compacted in the thickness direction are scattered in the laminated structure, and at least a part of the plurality of compacted portions. It is an absorbent article in which the hydrophilic fibers are exposed on the side facing the skin.

According to the present invention, there is provided an absorbent article having an excellent wearing feeling, in which liquid residue and liquid return are less likely to occur at a position close to the wearer's skin.

FIG. 1 is a plan view schematically showing a skin-facing surface, that is, a surface sheet side of a deployable disposable diaper according to an embodiment of the absorbent article of the present invention, and the elastic members of each part are stretched and expanded in a plane shape. It is a plan view in the unfolded state. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II of FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of the skin-side core wrap sheet according to the present invention along the thickness direction. 4 (a) to 4 (d) are plan views schematically showing the pattern of the compacted portion in the skin-side core wrap sheet according to the present invention, respectively. 5 (a) to 5 (d) are plan views schematically showing other patterns of the compacted portion in the skin-side core wrap sheet according to the present invention, respectively. 6 (a) and 6 (b) are plan views schematically showing still another pattern of the compacted portion in the skin-side core wrap sheet according to the present invention, respectively.

Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on an example of a deployable disposable diaper which is a preferred embodiment thereof. 1 and 2 show the deployable disposable diaper 1 of the present embodiment. The diaper 1 has a vertical direction X corresponding to a direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction Y orthogonal to the vertical direction X, and the inseam 1M arranged in the crotch portion and the crotch portion 1M. It has a ventral side 1F and a dorsal part 1R extending before and after it. The ventral side 1F, the inseam 1M, and the dorsal side 1R correspond to each region when the diaper 1 is divided into three equal parts in the vertical direction X. The inseam 1M has an excretion portion facing portion that is arranged to face the excretion portion of the wearer's penis, anus, etc. when the diaper 1 is worn, and the excretion portion facing portion is usually in the vertical direction X of the diaper 1. It is located in or near the center.

As shown in FIGS. 1 and 2, the diaper 1 is arranged on the skin facing surface side of the absorbent body 4 having the absorbent core 40 and the absorbent body 4, and is located closer to the wearer's skin than the absorbent body 4. A liquid-permeable surface sheet 2 that can come into contact with the wearer's skin when worn, and a liquid-free surface sheet 2 that is arranged on the non-skin facing surface side of the absorber 4 and is located farther from the wearer's skin than the absorber 4. It is provided with a transparent or water-repellent back sheet 3, and in a plan view as shown in FIG. 1, the central portion of the vertical direction X located at the lower crotch 1M is constricted inward and is long in one direction, that is, the vertical direction X. It has a vertically long hourglass shape. The front surface sheet 2 and the back surface sheet 3 each have a size larger than that of the absorber 4 interposed between the two sheets 2 and 3, and form the outer shape of the unfolded and stretched diaper 1 as shown in FIG. ing.

In the present specification, the "skin facing surface" is a surface of the absorbent article or its constituent member (for example, the absorbent core 40) that is directed toward the skin side of the wearer when the absorbent article is worn, that is, relatively. The side close to the wearer's skin, and the "non-skin facing surface" is the surface of the absorbent article or its constituent members that faces the opposite side (clothing side) of the absorbent article when the absorbent article is worn, that is, relative to the skin. It is the side far from the wearer's skin. In addition, "when worn" here means a state in which a normal proper wearing position is maintained.

A band-shaped elastic member 11 is formed between the front surface sheet 2 and the back surface sheet 3 at the waist portion of each of the ventral side portion 1F and the dorsal side portion 1R, that is, the end portion in the vertical direction X, which is an abbreviation for the lateral direction Y of the diaper 1. It is fixed in a laterally extended state over the entire length, whereby waist gathers are formed on the waist portion when the diaper 1 is worn due to the contraction of the elastic member 11. Further, a plurality of thread-like elastic members 12 are fixed in a laterally extended state between the front surface sheet 2 and the back surface sheet 3 in the waist circumference portion corresponding to the waist circumference of the wearer in the dorsal side portion 1R. As a result, gathers around the waist are formed by the contraction of the elastic member 12 around the waist when the diaper 1 is worn. Further, side sheets 5 are arranged on both the left and right sides along the vertical direction X on the surface sheet 2 side of the diaper 1, that is, the skin facing surface side. The side sheet 5 has an inner edge portion along the vertical direction X and an outer edge portion located outside the inner edge portion in the horizontal direction Y and along the vertical direction X, and has a plane as shown in FIG. Visually, the inner edge portion overlaps with the absorber 4, and the outer edge portion extends outward in the horizontal direction Y from the side edge of the absorber 4 along the vertical direction X, and as shown in FIG. 2, the back surface sheet. It is joined with 3. A thread-like elastic member 13 is fixed in an extended state along the vertical direction X between the side seat 5 and the back seat 3 in the left and right leg portions arranged around the wearer's legs. A pair of leg gathers are formed on the leg portion when the diaper 1 is worn due to the contraction of the elastic member 13. Further, a thread-like elastic member 14 is fixed to the inner edge portion of the side sheet 5 in an extended state along the vertical direction X, and the inner edge portion is at least 1M in the inseam, specifically, for example. The inseam 1M, the ventral 1F, and the dorsal 1R near the inseam 1M are free ends that are not joined to the surface sheet 2 and other components of the diaper 1, and are ventral. The front and rear ends of the vertical direction X on the 1F and the dorsal side 1R are joined to the surface sheet 2 (not shown). Due to the configuration of the side seat 5, the contraction force of the elastic member 14 acts in the vertical direction X when the diaper 1 is worn, and the side seat 5 has at least the inner edge of the crotch portion 1M which is a free end. In, a pair of left and right leak-proof cuffs are formed by standing up toward the wearer's skin starting from the joint with the back surface sheet 3. The front surface sheet 2, the back surface sheet 3, the absorber 4, the side sheets 5, and the elastic members 11 to 14 are bonded to each other by a known bonding means such as a hot melt adhesive.

As shown in FIG. 1, a pair of fastening tapes 6 and 6 are provided on both side edges of the dorsal portion 1R of the diaper 1 along the vertical direction X. A fastening portion 61 made of a male member of a mechanical hook-and-loop fastener is attached to the fastening tape 6. Further, a landing region 7 made of a female member of a mechanical hook-and-loop fastener is formed on the non-skin facing surface of the ventral side 1F of the diaper 1. In the landing region 7, a female member of a mechanical hook-and-loop fastener is attached to the non-skin facing surface of the back surface sheet 3 forming the non-skin facing surface on the ventral side 1F by a known joining means such as an adhesive or a heat seal. It is formed by joining and fixing, and the fastening portion 61 of the fastening tape 6 can be detachably fastened.

As the surface sheet 2, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and it is assumed that the surface sheet 2 is a liquid permeable sheet capable of permeating body fluids such as urine and feces. As the material, a woven fabric made of synthetic fibers or natural fibers, a non-woven fabric, a porous sheet, or the like can be used. As an example of the surface sheet 2, a non-woven fabric made of a natural fiber such as cotton or a non-woven fabric made of various synthetic fibers subjected to a hydrophilic treatment can be used. For example, a core-sheath structure type (including side-by-side type) composite fiber using polypropylene or polyester as a core component and polyethylene as a sheath component is made into a web by carding, and then a non-woven fabric (after that, a hole is opened at a predetermined position) by an air-through method. Treatment may be applied). Further, from the viewpoint of high liquid permeability (dry feeling), a perforated sheet made of polyolefin such as low-density polyethylene can also be preferably used.
As the back sheet 3, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and liquid impermeable (including water repellency) and moisture permeable ones are preferable. Used. Specifically, in order to obtain sufficient water vapor permeability, a film made of a synthetic resin such as polyethylene in which fine powder composed of a filler such as calcium carbonate is dispersed is stretched, and a porous film provided with fine pores is a back sheet. Can be suitably used as 3.
As the side sheet 5, a sheet that can be used as the back sheet 3 can be used.

The absorber 4 includes a liquid-retaining absorbent core 40, a skin-side core wrap sheet 41 that covers the skin-facing surface of the absorbent core 40, and a non-skin-side core that covers the non-skin facing surface of the absorbent core 40. It is configured to include a wrap sheet 49. The absorbent core 40 and the skin side core wrap sheet 41 and the non-skin side core wrap sheet 49 are joined by a known joining means such as a hot melt adhesive. In a plan view as shown in FIG. 1, the absorber 4 (absorbent core 40) has an hourglass-like shape in which the central portion of the vertical direction X located at the lower crotch 1M is constricted inward and has a vertically long shape that is long in the vertical direction X. have.

The absorbent core 40 is mainly composed of an absorbent material, and the content of the absorbent material in the absorbent core 40 is usually about 100% by mass. As the absorbent material, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation. For example, hydrophilic fibers such as wood pulp and synthetic fibers treated with a hydrophilic agent. And water-absorbent polymer particles. Examples of the structure of the absorbent core 40 include a structure of hydrophilic fiber slabs, a structure in which water-absorbent polymer particles are supported on the slab, or a structure consisting of only water-absorbent polymer particles.

In the present embodiment, as shown in FIG. 2, the non-skin side core wrap sheet 49 has a longer lateral Y length than the skin side core wrap sheet 41. The non-skin side core wrap sheet 49 covers the entire non-skin facing surface of the absorbent core 40, and extends outward in the horizontal direction Y from both side edges along the vertical direction X of the absorbent core 40. The protruding portion is wound up on the skin-facing surface of the skin-side core wrap sheet 41 that abuts on the skin-facing surface of the absorbent core 40. The non-skin side core wrap sheet 49 may be the same as or different from the skin side core wrap sheet 41 in terms of its composition, and various materials conventionally used for absorbent articles such as disposable diapers such as paper and non-woven fabric can be used. It can be used without particular limitation. An example of the non-woven fabric constituting the non-skin side core wrap sheet 49 is a hydrophilic non-woven fabric made of fibers that have been subjected to a hydrophilic treatment. The non-woven core wrap sheet has higher strength than the paper one and is less likely to be torn during processing, and when the absorbent polymer particles are used as the absorbent material constituting the absorbent core 40, the core wrap sheet is made of water-absorbent polymer particles. It has a feature that it can flexibly cope with the deformation of the absorbent core 40 due to the swelling of the water-absorbent polymer particles.

FIG. 3 shows a cross section of the skin-side core wrap sheet 41, which is one of the main characteristic portions of the diaper 1, along the thickness direction. As shown in FIG. 3, the skin-side core wrap sheet 41 forms the skin-facing surface 41a of the sheet 41, and the skin-side layer 42 relatively close to the wearer's skin and the non-skin-facing surface of the sheet 41. It forms 41b and includes a laminated structure (two-layer structure) with a non-skin side layer 43 that is relatively far from the wearer's skin. The skin side layer 42 is arranged to face the surface sheet 2, and the non-skin side layer 43 is arranged to face the absorbent core 40. The skin-side layer 42 and the non-skin-side layer 43 are integrated at least via a compaction portion 46 described later, and depending on the manufacturing method, the constituent fibers of both layers 42 and 43 are further entangled with each other, and an adhesive or the like is used. It can also be integrated by other integrating means such as joining means.

Both the skin side layer 42 and the non-skin side layer 43 are fiber aggregates. The form of such a fiber aggregate is not particularly limited, and examples thereof include non-woven fabric, woven fabric, and paper. In a typical form, the skin side layer 42 is a non-woven fabric and the non-skin side layer 43 is paper.

As the non-woven fabric constituting the skin side layer 42, those produced by various manufacturing methods can be used without particular limitation, and examples thereof include air-through non-woven fabric, spunbond non-woven fabric, spunlace non-woven fabric, melt blown non-woven fabric, resin bond non-woven fabric, needle punch non-woven fabric and the like. Be done. It is also possible to use a laminated body in which two or more kinds of these non-woven fabrics are combined, or a laminated body in which these non-woven fabrics and a film or the like are combined. Among these non-woven fabrics, spunbonded non-woven fabrics and melt-blown non-woven fabrics are preferable because they are superior to air-through non-woven fabrics and the like because they are excellent in the effect of preventing leakage of absorbent materials such as water-absorbing polymer particles contained in the absorbent core 40.

The skin side layer 42 is mainly composed of thermoplastic fibers 44, and the non-skin side layer 43 is mainly composed of non-thermoplastic hydrophilic fibers 45. The skin side layer 42 contains at least 80% by mass or more of the thermoplastic fiber 44, and the content of the thermoplastic fiber 44 may be 100% by mass with respect to the total mass of the skin side layer 42. Further, the non-skin side layer 43 may contain at least 80% by mass or more of the hydrophilic fibers 45, and the content of the hydrophilic fibers 45 may be 100% by mass with respect to the total mass of the non-skin side layer 43. In FIG. 3, the thermoplastic fiber 44 is indicated by a relatively thick line and the hydrophilic fiber 45 is indicated by a relatively thin line from the viewpoint of facilitating understanding, but it is irrelevant to the actual fiber thickness. Is.

As the thermoplastic resin which is the material of the thermoplastic fiber 44, those usually used for constituent fibers such as non-woven fabrics can be used without particular limitation, and for example, polyethylene, polypropylene, polybutene-1, polypentene-1, and polypentene-1 and Polyesters such as these random or block copolymers; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon-6 and nylon-66 can be mentioned. The thermoplastic fiber 44 may be a single fiber formed by using a single thermoplastic resin, or may be a composite fiber formed by using two or more kinds of thermoplastic resins. Examples of the composite fiber include core-sheath type fiber, side-by-side type fiber, split type fiber, alternating arrangement type fiber, and sea-island type fiber. The skin side layer 42 may contain two or more types of thermoplastic fibers 44. Among these, polyethylene and polypropylene are preferably used as the thermoplastic fiber 44 because they are inexpensive and have a relatively low melting point, so that the compacted portion 46 described later can be easily formed.

The hydrophilic fiber 45 is a non-thermoplastic and hydrophilic fiber, in contrast to the thermoplastic fiber 44 being hydrophobic. In the present invention, the hydrophilicity of the fiber is determined based on the contact angle with water measured by the following method, and if the contact angle is less than 90 degrees, it is hydrophilic, and if it is 90 degrees or more, it is hydrophobic. be. The smaller the contact angle with water measured by the following method, the higher the hydrophilicity (lower hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (higher hydrophobicity). In the skin-side core wrap sheet 41, the contact angle of the hydrophobic thermoplastic fiber 44, which is the main component of the skin-side layer 42, with water is 90 degrees or more, and the hydrophilic fiber 45, which is the main component of the non-skin-side layer 43, is formed. The contact angle with water is less than 90 degrees.

<Measurement method of contact angle>
The fibers are taken out from the measurement target (skin side core wrap sheet), and the contact angle of water with respect to the fibers is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The amount of liquid discharged from the inkjet water droplet discharge unit (Pulse injector CTC-25 manufactured by Cluster Technology Co., Ltd., having a discharge unit hole diameter of 25 μm) is set to 20 picolitres, and the water droplet is dropped directly above the fiber. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. From the viewpoint of image analysis later, the recording device is preferably a personal computer incorporating a high-speed capture device. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water droplets on the fibers is the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2, image processing algorithm. Is non-reflective, image processing image mode is frame, threshold level is 200, curvature correction is not performed), the angle between the surface of the water droplet that comes into contact with the air and the fiber is calculated, and the contact Make a corner. The fiber taken out from the object to be measured is cut to a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and maintained horizontally. Measure the contact angles at two different points for each fiber. The contact angle of N = 5 fibers is measured to one digit after the decimal point, and the average value of the measured values at 10 points in total (rounded to the second digit after the decimal point) is defined as the contact angle of the fiber with water. The measurement environment is room temperature 22 ± 2 ° C. and humidity 65 ± 2% RH.

When the constituent member (for example, the skin-side core wrap sheet) is taken out from the absorbent article and evaluated and measured, when the constituent member is fixed to another constituent member by an adhesive, fusion, or the like. , The fixed part is removed by applying a solvent, blowing hot air with a dryer, blowing a cold spray (for example, a commercially available product manufactured by Nichiban Co., Ltd.), and then taking out.

As the hydrophilic fiber 45, various hydrophilic fibers conventionally used for absorbent articles can be used without particular limitation on the premise that the hydrophilic fiber 45 does not have thermoplasticity, and a typical one is a cellulose fiber. Examples of the cellulose fiber include wood pulp such as coniferous kraft pulp and broadleaf kraft pulp, natural cellulose fiber such as cotton pulp and non-wood pulp such as walla pulp; and regenerated cellulose fiber such as rayon and cupra, and one of them. Can be used alone or in combination of two or more. Of these, wood pulp is particularly preferable. The reason is that the fiber length of wood pulp is shorter than that of recycled cellulose fiber and non-wood pulp, so when wood pulp is used as hydrophilic fiber 45, the hydrophilic fiber 45 made of the wood pulp is on the skin side. It easily passes through the gaps between the thermoplastic fibers 44 constituting the layer 42, and therefore, “a state in which the hydrophilic fibers 45 are exposed on the skin facing surface 41a side of the compacted portion 46 of the skin side core wrap sheet 41” is obtained. This is because it is easy to get rid of.

In the skin-side core wrap sheet 41, the laminated structure of the skin-side layer 42 and the non-skin-side layer 43 has a compacted portion 46 that is compacted in the thickness direction of the laminated structure (sheet 41), as shown in FIG. Is formed. A plurality of compacted portions 46 are scattered on the skin-side core wrap sheet 41 in a predetermined pattern as shown in FIGS. 4 and 5, for example. 4 and 5 are plan views schematically showing the skin-facing surface of the absorber 4, that is, the skin-side core wrap sheet 41 side, and are examples of the pattern of the consolidation portion 46.

The consolidation portion 46 is a portion of the skin-side core wrap sheet 41 that is consolidated in the thickness direction, and this consolidation typically promotes melting of the thermoplastic fiber 44 such as heat and ultrasonic waves. It is carried out by embossing (squeezing) with melting promoting means. When the skin-side core wrap sheet 41 is squeezed with such a melting promoting means, it may be squeezed from either the skin-side layer 42 or the non-skin-side layer 43, and the squeezing is performed on both layers 42 and 43. However, from the viewpoint of promoting the melting of the thermoplastic fiber 44, it is preferable to apply the squeezing to the skin side layer 42. The compacted portion 46 is a high-density portion of the skin-side core wrap sheet 41 in which the interfiber gap is narrower or the interfiber gap is substantially absent as compared with the portion other than the compacted portion 46 (non-consolidated portion). The non-consolidated portion is a low-density portion having a wider interfiber gap than the compacted portion 46.

As one of the main features of the diaper 1, the skin facing surface 41a in at least a part of the plurality of compacted portions 46 scattered on the skin side core wrap sheet 41 (laminated structure of the skin side layer 42 and the non-skin side layer 43). The point that the hydrophilic fiber 45 is exposed can be mentioned on the side. That is, as shown in FIG. 3, in the compacted portion 46 of the skin-side core wrap sheet 41, a part of the hydrophilic fibers 45, which is the main component of the non-skin-side layer 43, enters the skin-side layer 42 and the skin of the compacted portion 46. The diaper 1 is characterized by being exposed on the facing surface 41a side. In the skin-side core wrap sheet 41, whether or not the hydrophilic fibers 45 are exposed on the skin-facing surface 41a side of the consolidated portion 46 can be confirmed by microscopic observation of a cross section along the thickness direction of the sheet 41. Specifically, it can be carried out by the following method.

<How to confirm that the fibers on the non-skin facing surface side are exposed on the skin facing surface side of the consolidated part>
Immerse the sheet to be evaluated (skin-side core wrap sheet 41) in a 0.5 mass% blue aqueous solution (Edible Blue No. 1 of Aizen Food Color manufactured by Daiwa Kasei), allow it to stand for 3 minutes, and then remove the sheet from the aqueous solution. Place the removed sheet on a pre-laid paper (Kim Towel, manufactured by Nippon Paper Crecia Co., Ltd.) with the skin-facing side facing down, and dehydrate the sheet from above with a load of 3 kPa over 1 minute. do. By this operation, the hydrophilic fibers among the constituent fibers of the evaluation target sheet are dyed. The compacted portion 46 to be evaluated of the dyed sheet thus obtained is cut along the lateral direction Y of the diaper 1 using a single-edged razor manufactured by Feather, and the cut surface thereof is cut with a microscope (VHX-1000 manufactured by KEYENCE). ) Is observed at a magnification of 200 to 500 times, and whether or not the non-thermoplastic hydrophilic fiber 45, which is the main component of the non-skin side layer 43, is exposed on the skin facing surface side 41a side of the compacted portion 46. Check if. Since the hydrophilic fibers 45 are dyed in the consolidated portion 46, it is easy to determine whether or not the consolidated portion 46 is exposed on the skin-facing surface side 41a.

As described above, the compacted portion 46 is typically formed by embossing with heat, ultrasonic waves, etc., but in the skin-side layer 42 of the consolidated portion 46 formed by such embossing, the main body thereof is used. Since the thermoplastic fiber 44 to be formed is softened and melted by heat and ultrasonic waves during embossing, the original form of the fiber aggregate is lost and it is formed into a film. As shown in FIG. 3, the film-formed skin-side layer 42 (the part colored in gray in FIG. 3) of the compacted portion 46 forms the main body of the non-skin-side layer 43. A part of the hydrophilic fiber 45 has entered and is exposed on the skin facing surface 41a side. That is, in the plan view of the compacted portion 46 on the skin facing surface 41a side, one or more exposed portions of the hydrophilic fibers 45 are present in the filmed skin side layer 42. The hydrophilic fibers 45 forming the exposed portion are continuous from the skin facing surface 41a side to the non-skin facing surface 41b side of the skin side core wrap sheet 41.

Due to such a characteristic configuration of the skin-side core wrap sheet 41 having the compaction portion 46, the diaper 1 is less likely to cause liquid residue or liquid return at a position close to the wearer's skin, and is excellent in wearing feeling. That is, the skin-facing surface 41a of the skin-side core wrap sheet 41 is a portion that first comes into contact with body fluid such as urine that has permeated the surface sheet 2, and is a skin-side layer 42 mainly composed of hydrophobic thermoplastic fibers 44. Since it is a part of the above, basically, the diffusivity of the body fluid in the surface direction is poor in the entire area, and the wet spread of the body fluid is unlikely to occur. That is, since the skin-side core wrap sheet 41 has a low hydrophilicity of the skin-side layer 42, which is relatively close to the wearer's skin, in the diaper 1, the body fluid is directed toward the surface at a position relatively close to the wearer's skin. Diffusion is suppressed, so that skin troubles due to high humidity around the skin are less likely to occur, and the wearer is less likely to feel wet, and an excellent wearing feeling can be obtained. Further, the skin-side core wrap sheet 41 basically has poor permeability in the thickness direction of the body fluid, and the body fluid permeates the sheet 41 and shifts to the absorbent core 40 in the portion other than the compacted portion 46. However, in the compacted portion 46, a part of the skin-facing surface 41a formed into a film is an exposed portion of the hydrophilic fiber 45 extending from the non-skin facing surface 41b side. Since the hydrophilic fibers 45 continuous from the exposed portion to the non-skin facing surface 41b side function as a liquid passage (liquid passing trigger) for the body fluid, the body fluid that remains wet on the skin facing surface 41a without spreading can be removed. It is rapidly taken into the sheet 41 through the compaction portion 46 (exposed portion of the hydrophilic fiber 45). Further, the non-skin side layer 43 of the skin side core wrap sheet 41 is mainly composed of the hydrophilic fiber 45, and the liquid can be absorbed by the capillary force of the hydrophilic fiber 45 itself, even if it is the compacted portion 46. Since high water permeability can be exhibited, the body fluid taken in by the skin-side layer 42 of the consolidation portion 46 permeates the body fluid and reaches the non-skin-side layer 43, and is rapidly diffused in the plane direction while absorbing the core 40. It shifts to the side and is absorbed and held by the absorbent core 40. In this way, the body fluid is diffused in the surface direction by the skin-side core wrap sheet 41 and then transferred to the absorbent core 40 so that the absorption performance such as the absorption capacity of the absorbent core 40 can be utilized more effectively. Become. In addition, the skin side layer 42, which has low hydrophilicity, transfers the body fluid absorbed and held by the absorbent core 40 to the surface sheet 2 side due to the wearer's body pressure or the like. Since it effectively inhibits, liquid return is unlikely to occur in diaper 1.

From the viewpoint of ensuring the action and effect of the skin-side core wrap sheet 41 described above more reliably, particularly regarding the diffusion of body fluid in the surface direction, this is suppressed at a position relatively close to the wearer's skin, and the wearer's From the viewpoint of promoting this at a position relatively far from the skin, in the sheet 41, the skin-side layer 42 has a lower hydrophilicity than the non-skin-side layer 43 in the portion other than the compacted portion 46, in other words. The non-skin side layer 43 preferably has a higher degree of hydrophilicity than the skin side layer 42. The hydrophilicity of the sheet (layer) referred to here is evaluated by the water droplet disappearance rate measured by the following method. The smaller the value of the water droplet disappearance rate, the lower the hydrophilicity, and the larger the value of the water droplet disappearance rate, the higher the hydrophilicity. Therefore, it is preferable that the magnitude relationship of "water droplet disappearance rate of the skin side layer 42 <water droplet disappearance rate of the non-skin side layer 43" is established.

<Measurement method of water droplet disappearance rate>
A sheet to be evaluated (for example, a skin-side core wrap sheet 41 or a skin-side layer 42 or a non-skin-side layer 43 thereof) is fixed in the air so that the surface becomes horizontal, and at any 20 positions on the upper surface of the sheet. Water droplets (1 drop 2 μl) of physiological saline (saline solution having a concentration of 0.9% by mass) are dropped using a microsyringe. If the hydrophilicity of the sheet to be evaluated is high, the water droplets are immediately absorbed by the sheet and disappear after dropping, and if the hydrophilicity of the sheet is low, the water droplets are not absorbed and remain on the upper surface of the sheet. The disappearance of the water droplets is determined by visually observing the upper surface of the sheet 10 seconds after the water droplets are dropped. The water droplet disappearance rate (%) is obtained by calculating the ratio of the water droplet disappearance points within 10 seconds out of the measurement at 20 points.

The ratio of the water droplet disappearance rate of the portion other than the consolidated portion 46 of the skin side layer 42 to the water droplet disappearance rate of the portion other than the consolidated portion 46 of the non-skin side layer 43 is based on the premise that the former is smaller than the latter. The latter is preferably 0.5 or less, more preferably 0.3 or less.
The water droplet disappearance rate of the portion of the skin side layer 42 other than the consolidated portion 46 is preferably 50% or less, more preferably 30% or less, and the lower limit is 0%.
The water droplet disappearance rate of the non-skin side layer 43 other than the consolidated portion 46 is preferably 50% or more, more preferably 80% or more, and the upper limit is 100%.
The adjustment of the water droplet number disappearance rate, that is, the adjustment of the hydrophilicity, is performed on the types of the constituent fibers (thermoplastic fibers 44) of the skin side layer 42 and the constituent fibers (hydrophilic fibers 45) of the non-skin side layer 43, and the hydrophobizing agent (mainly). It can be carried out by using a hydrophilic agent (mainly for the non-skin side layer 43) or a hydrophilic agent (for the non-skin side layer 43).

Further, from the viewpoint of ensuring the action and effect of the skin-side core wrap sheet 41 described above more reliably, among the plurality of compacted portions 46 existing in the laminated structure of the skin-side layer 42 and the non-skin-side layer 43, The ratio of the consolidated portion (hereinafter, also referred to as “hydrophilic portion exposed compacted portion”) in which the hydrophilic fibers 45 (consolidated fibers of the non-skin side layer 43) are exposed on the skin facing surface 41a side, that is, “(hydrophilic portion exposed) The value calculated by "the number of consolidated portions / 10) x 100" is preferably 50% or more, and more preferably 80% or more.
Whether or not a certain consolidation portion is the hydrophilic portion exposed consolidation portion is confirmed by the following method. That is, with respect to the consolidated portion to be evaluated, it is confirmed by the above method whether or not the fibers (hydrophilic fibers) on the non-skin facing surface side are exposed on the skin facing surface side of the compacted portion, and the fibers are exposed. If can be confirmed at even one place, the compacted portion is assumed to be the hydrophilic portion exposed and compacted portion.

In particular, when 10 are arbitrarily selected from the plurality of compacted portions 46 existing in the laminated structure of the skin side layer 42 and the non-skin side layer 43, the hydrophilic portion exposed and compacted portion is formed in the 10 compacted portions 46. It is more effective when the proportion is 50% or more.

Further, the length of the consolidation portion 46 in the longitudinal direction (when the shape of the consolidation portion 46 in a plan view is an anisotropic shape such as a rectangular shape) or the length in the vertical direction X (the shape of the consolidation portion 46 in a plan view is a circular shape). When the size (in the case of an isotropic shape) exceeds 2 mm, the fibers (hydrophilic fiber 45) on the non-skin facing surface side are at least two locations at intervals of 2 mm in the longitudinal direction or the longitudinal direction X of the consolidated portion 46. It is desirable that the surface facing the skin 41a is exposed.

The pattern (shape in plan view, arrangement, etc.) of the consolidation portion 46 can be arbitrarily set, and FIGS. 4 and 5 are only a part of specific examples thereof. The plan-view shape of the consolidation portion 46 is a short line segment as shown in FIG. 4 (a), an oblong shape as shown in FIGS. 4 (b) to 4 (d), and FIGS. 5 (a) and 5 (b). It may be a continuous linear shape extending in the vertical direction X as shown in FIG. 5 (c) or a grid shape as shown in FIGS. 5 (c) and 5 (d).

As shown in FIG. 4, in the pattern in which a large number of relatively small compacted portions 46 are scattered, for example, the plan view shape of the compacted portions 46 is a circular shape, a triangular shape, a quadrangular shape, a polygonal shape of a pentagon or more, a circular shape, and the like. It may have an elliptical shape or the like, and its arrangement may be a staggered pattern. Further, in the pattern in which a large number of relatively small compacted portions 46 are scattered, the number of the compacted portions 46 per unit area is as shown in FIGS. 4 (a) and 4 (b) of the skin-side core wrap sheet 41. It may be substantially uniform over the entire area, or as shown in FIG. 4 (c), in a part of the vertical direction X (inseam 1M), more than other parts in the same direction (ventral 1F, dorsal 1R). Alternatively, as shown in FIG. 4D, there may be more in a part of the lateral direction Y (central portion in the lateral direction) than in other portions in the same direction (both ends in the lateral direction).

Further, in the pattern in which the consolidated portion 46 having a plane line-of-sight shape exists as shown in FIG. 5, as shown in FIG. 5A, a straight line extending in the vertical direction X only in a part of the vertical direction X (lower crotch 1M). The shape-shaped compacted portion 46 may exist, or as shown in FIG. 5B, there is a linear compacted portion 46 extending in the vertical direction X over the entire length of the skin-side core wrap sheet 41 in the vertical direction X. You may be. In both FIGS. 5A and 5B, a plurality of linear consolidation portions 46 extending in the vertical direction X are intermittently arranged at predetermined intervals in the horizontal direction Y.

However, in consideration of further improvement of utilization efficiency of the absorbent core 40, effective prevention of liquid return, and the like, it is preferable to diffuse body fluid such as urine in the vertical direction X of the diaper 1 as much as possible. From this point of view, as a pattern of the consolidation portions 46, as shown in FIG. 6, a plurality of consolidation portions 46 are arranged at predetermined intervals 46X and 46Y in both the vertical direction X and the horizontal direction Y, and are arranged vertically. It is preferable that the interval 46X in the direction X is shorter than the interval 46Y in the lateral direction Y. The distance 46X is the distance between the two adjacent compacted portions 46,46 in the vertical direction X, and the distance 46Y is the distance between the two adjacent compacted portions 46,46 in the horizontal direction Y. The distance between the parts closest to each other. With respect to the spacing between the consolidated portions 46, the magnitude relationship of "spacing 46X <spacing 46Y" is established, so that the body fluids in the skin-side core wrap sheet 41 are more likely to be adjacent to each other. It will be preferentially diffused in the adjacent vertical direction X.

From the same viewpoint, 1) the compacted portion 46 extends in the vertical direction X, or 2) the non-consolidated portion (consolidated portion 46) sandwiched between two or more compacted portions 46 in the skin-side core wrap sheet 41. It is preferable that the portion other than the above portion) extends in the vertical direction X. It is more preferable that the skin-side core wrap sheet 41 includes both the above 1) and 2).

Regarding 1) above, "the compacted portion 46 extends in the vertical direction X" means that the planar view shape of the compacted portion 46 is long in one direction such as a linear shape, a rectangular shape, or an elliptical shape. In this case, it means that the angle formed by the longitudinal direction (major axis direction) and the vertical direction X of the diaper 1 is 45 degrees or less. Of the eight patterns of the consolidated portions 46 shown in FIGS. 4 to 5, in FIGS. 4 (a), 5 (a), and 5 (b), all the shapes of the plurality of compacted portions 46 in a plan view are vertical. It has a linear shape parallel to the direction X, and in FIGS. 5 (c) and 5 (d), a part of the consolidated portions 46 in a plan view has a linear shape parallel to the vertical direction X. All of these eight patterns satisfy the above 1).

With respect to the above 2), at least the four patterns of FIGS. 5 (a) to 5 (d) are portions sandwiched by the consolidated portions 46 having a linear shape in a plan view extending in the vertical direction X and / or the horizontal direction Y. The non-consolidated portion 47 has a rectangular shape that is long in the vertical direction X in a plan view, and all of these four patterns satisfy the above 2). Further, it can be said that the four patterns of FIGS. 4 (a) to 4 (d) also satisfy the above 2) because it can be seen that the non-consolidated portion 47 is continuous in the vertical direction X.

Further, from the viewpoint of promoting the diffusion of body fluid such as urine in the vertical direction X, the hydrophilic fiber 45 which is the main component of the non-skin side layer 43 is preferably oriented in the vertical direction X.

By the way, as described above, the presence of the consolidation portion 46 appropriately controls the liquid permeability in the thickness direction and the liquid diffusivity in the surface direction of the skin-side core wrap sheet 41, and as a result, the sheet 41 is imparted with high water permeability. However, since the consolidation portion 46 itself is a relatively hard portion including the portion where the fiber is formed into a film, if the consolidation portion 46 is excessive, the sheet 41 becomes hard, and the basic performance that the diaper 1 should have is There is a risk that the flexibility of one is impaired. Therefore, it is preferable to place the consolidation portion 46 in the crotch portion 1M, which is particularly required to have high water permeability. From such a viewpoint, it is preferable that the total area of the consolidated portion 46 of the crotch portion 1M is larger than that of the ventral side portion 1F and the dorsal side portion 1R. The pattern of the consolidation portion 46 in FIG. 5C is a specific example in which such a magnitude relationship is established. As described above, the ventral portion 1F, the inseam portion 1M, and the dorsal portion 1R correspond to each region when the diaper 1 is divided into three equal parts in the vertical direction X.

The ratio of the total area of the consolidated portion 46 in the inseam 1M to the total area of the consolidated portion 46 in the ventral side 1F or the dorsal side 1R is preferably larger in the former than in the latter, and preferably as the former / latter. It is 1.5 or more, more preferably 2 or more, and preferably 5 or less, still more preferably 3 or less.
The total area of the compacted portion 46 in the crotch portion 1M, preferably 750 mm ² or more, more preferably 1500 mm ² or more, and, preferably 6000 mm ² or less, more preferably 3000 mm ² or less.
The total area of the consolidated portion 46 on the ventral side 1F and the total area of the consolidated portion 46 on the dorsal side 1R are preferably 500 mm ² or more, more preferably 1000 mm ² or more, and preferably 5000 mm ² or less, respectively. Is 2300 mm ² or less.

Further, even if the total area of the consolidated portion 46 existing in the region is the same in a part of the skin-side core wrap sheet 41 and the other region, if the pattern of the consolidated portion 46 is different between the two regions, the body fluid Differences in diffusivity can occur. For example, in the pattern (Pattern A) in which a plurality of consolidated portions having a relatively small area are arranged close to each other, one relatively large consolidated portion having the same area as the total area of the plurality of consolidated portions is provided. It is superior in liquid diffusivity in the plane direction in the non-skin side layer 43 as compared with the pattern (pattern B) in which only the patterns are arranged. Here, focusing on the length of the contour line, that is, the circumference of the consolidation portion, rather than the area of the consolidation portion, the pattern A is the sum of the circumferences of each of the plurality of consolidation portions as compared with the pattern B. Is long. Considering the above, as the pattern of the consolidation portion 46, the pattern A is particularly preferable, that is, a pattern in which the total peripheral length of the consolidation portion 46 existing in the unit region of the skin-side core wrap sheet 41 is as long as possible is preferable. ..

From the viewpoint of ensuring the action and effect of the skin-side core wrap sheet 41 described above, it is preferable that the thicknesses of the thermoplastic fibers 44 and the hydrophilic fibers 45, more specifically, the fiber diameters are both small. .. Since the fiber diameter of the thermoplastic fiber 44, which is the main component of the skin-side layer 42, is relatively small, the fiber 44 is more likely to be melted and deformed due to consolidation, and the compaction portion 46 is hydrophilic on the skin-facing surface side. The exposure of the sex fibers 45 is more likely to occur, and the fiber diameter of the hydrophilic fibers 45, which is the main component of the non-skin side layer 43, is relatively small, so that such exposure of the fibers 45 is more likely to occur. From the above points, the fineness of the thermoplastic fiber 44 is preferably 0.7 dtex or more, more preferably 1.0 dtex or more, and preferably 4.4 dtex or less, still more preferably 2.2 dtex or less. Further, the thickness of the hydrophilic fiber 45, that is, the diameter when the cross-sectional shape in the direction orthogonal to the length direction of the hydrophilic fiber 45 is circular, and the length of the long axis when the cross-sectional shape is elliptical or flat. Each is preferably 50 μm or less, more preferably 30 μm or less.

Further, from the viewpoint of ensuring continuity from the exposed portion of the compacted portion 46 on the skin-facing surface 41a side to the non-skin-facing surface 41b side, the function as a liquid guide can be more reliably performed, hydrophilic. The fiber length of the sex fiber 45 is preferably long. Specifically, the fiber length of the hydrophilic fiber 45 is preferably 1 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, further preferably 5 mm or less.

Further, the basis weight of the skin side layer 42 is preferably relatively small. When the basis weight of the skin side layer 42 becomes excessive, the film formation of the skin side layer 42 (thermoplastic fiber 44) in the compacted portion 46 is excessively promoted, and as a result, the skin facing the skin 41a side of the compacted portion 46 is filmed. The side layer 42 may completely block the hydrophilic fibers 45, making it difficult for the hydrophilic fibers 45 to be exposed to the skin facing surface 41a. From the above points, the basis weight of the skin side layer 42 is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, and preferably 20 g / m ² or less, still more preferably 15 g / m ² or less. be.

The skin-side core wrap sheet 41 is a non-woven fabric sheet of the non-skin-side layer 43, which is separate from the raw fabric sheet of the skin-side layer 42 (typically, a non-woven fabric mainly composed of thermoplastic fibers 44). (Typically, paper mainly composed of hydrophilic fibers 45) is superposed, and melting of the thermoplastic fibers 44 such as heat and ultrasonic waves is promoted at a predetermined portion of the laminate of both sheets. It can be manufactured by embossing (squeezing) with a melting promoting means. By this embossing process, the thermoplastic fibers 44 in the raw fabric sheet of the skin side layer 42 are melted, deformed and formed into a film, and the hydrophilic fibers 45 in the raw fabric sheet of the non-skin side layer 43 are formed into a film. It becomes easy to be exposed on the surface side of the part. In the skin-side core wrap sheet 41 manufactured by such a method, the portion where the embossed portion is applied becomes the compacted portion 46, and the skin-side layer 42 and the non-skin-side layer 43 are joined and integrated via the compacted portion 46. Has been converted. In this way, when the skin-side core wrap sheet 41 is manufactured by laminating two raw fabric sheets, the basis weight of the non-skin-side layer 43 is preferably 10 g / m from the viewpoint of maintaining the form as paper. ² or more, more preferably 13 g / m ² or more, preferably 30 g / m ² or less, still more preferably 20 g / m ² or less.

Further, the skin-side core wrap sheet 41 can also be produced by a known wet papermaking method using the raw fabric sheet of the skin-side layer 42, the paper slurry containing the hydrophilic fibers 45, and the papermaking net. Specifically, first, the raw sheet of the skin side layer 42 is placed on the papermaking net. Next, a paper slurry containing the hydrophilic fibers 45 is poured into the raw sheet on the papermaking net. The water in the poured paper material slurry sequentially permeates the raw fabric sheet and the papermaking net and flows down from below the papermaking net, and the hydrophilic fibers 45 in the paper material slurry are the constituent fibers (heat) of the raw fabric sheet. It is entangled with the plastic fibers 44) and stays in the raw sheet, whereby a wet sheet having a two-layer structure containing the hydrophilic fibers 45 and the thermoplastic fibers 44 is formed on the papermaking net. A suction means may be arranged on the opposite side of the papermaking net from the raw fabric sheet, and the suction means may promote dehydration of the raw fabric sheet. Then, after the wet sheet is dried by various drying means adopted in the wet papermaking method, melting that promotes melting of the thermoplastic fiber 44 such as heat and ultrasonic waves is performed on a predetermined portion of the drying sheet. By performing embossing (squeezing) with a promoting means, the desired skin-side core wrap sheet 41 can be obtained. In the skin-side core wrap sheet 41 manufactured by such a method, the portion where the embossed portion is applied becomes the compacted portion 46, and the integration of the skin-side layer 42 and the non-skin-side layer 43 is the compacted portion. In addition to 46, it is also made by entanglement of both fibers 44 and 45.

In the skin-side core wrap sheet 41 manufactured by such a wet papermaking method, usually, the surface side of the raw fabric sheet facing the papermaking net, the so-called wire surface side (the side opposite to the supply side of the paper slurry). Since the hydrophilic fibers 45 are unevenly distributed in, the wire surface side becomes the non-skin side layer 43. The distribution state of the hydrophilic fibers 45 on the skin-side core wrap sheet 41 can be adjusted by appropriately adjusting the pore diameter and pitch of the dehydration holes of the papermaking net. In particular, when the paper slurry containing the hydrophilic fibers 45 is poured into the raw fabric sheet and then a high-pressure water stream is sprayed onto the felt surface side of the raw fabric sheet, the compacted portion 46 formed by the subsequent embossing is formed. This is preferable because the hydrophilic fibers 45 are easily exposed on the skin-facing surface 41a side.

Although the present invention has been described above based on the embodiment, the present invention can be appropriately modified without being limited to the embodiment.
For example, in the portion of the skin-side core wrap sheet 41 other than the compacted portion 46, the skin-side layer 42 may be hydrophobic or hydrophilic. In order to increase the hydrophilicity of the skin side layer 42, a method of kneading a known hydrophilic agent such as a surfactant into the thermoplastic fiber 44 or applying it to the fiber surface can be adopted. However, as described above, from the viewpoint of suppressing the diffusion of body fluid in the skin side layer 42 in the surface direction, it is preferable that the skin side layer 42 has a lower hydrophilicity than the non-skin side layer 43, and the skin side layer 42 is preferably hydrophobic. Increasing the hydrophilicity of the skin-side layer 42 (making the skin-side layer 42 hydrophilic) is particularly effective in increasing the liquid permeability in the consolidated portion 46.

Further, for example, in the above-described embodiment, the non-skin side core wrap sheet 49 has a longer lateral Y length than the skin side core wrap sheet 41, but conversely, the skin side core wrap sheet 41 has a longer length. However, the length of the lateral Y may be longer than that of the non-skin side core wrap sheet 49, or the length of the lateral Y of both sheets 41 and 49 may be the same.
Further, in the above embodiment, the non-skin side core wrap sheet 49, which is separate from the skin side core wrap sheet 41, is adopted, but one continuous core wrap sheet can also be adopted. In that case, for example, one continuous core wrap sheet having a width of 2 times or more and 3 times or less the length of the lateral Y of the absorbent core 40 covers the entire surface of the absorbent core 40 facing the skin. In addition, the absorbent core 40 extends outward in the horizontal direction Y from both side edges along the vertical direction X, and the extending portion is wound below the absorbent core 40 so that the absorbent core 40 is non-skinned. A configuration that covers the entire surface of the facing surface can be adopted. In this one core wrap sheet, the portion covering the skin facing surface of the absorbent core 40 is the skin side core wrap sheet, and the portion covering the non-skin facing surface of the absorbent core 40 is the non-skin side core wrap sheet. ..

Further, from the viewpoint of improving absorbency and leakage resistance, liquid permeability made of paper or various non-woven fabrics, which is also called a sublayer or the like, is formed between the surface sheet 2 and the absorber 4 (skin side core wrap sheet 41). Sheets may be intervened. From the same viewpoint, a groove formed by integrally compacting the surface sheet 2 and the absorber 4 may be formed on the skin-facing surface of the diaper 1.
The present invention is not limited to the deployable disposable diapers as in the above embodiment, and broadly includes articles used for absorbing body fluids (urine, loose stools, menstrual blood, sweat, etc.) discharged from the human body, and is of a pants type. Disposable diapers, sanitary napkins, sanitary shorts and the like are also included.
All the parts of only one embodiment described above can be mutually used as appropriate. The following additional notes will be further disclosed with respect to the above-described embodiments of the present invention.

<1>
It has a vertical direction corresponding to a direction extending from the ventral side of the wearer to the dorsal side via the crotch part and a lateral direction orthogonal to the vertical direction, and the crotch part arranged in the crotch part and the abdomen extending before and after the crotch part. An absorbent article having side and dorsal portions and comprising a liquid-retaining absorbent core and a skin-side core wrap sheet covering the skin-facing surface of the absorbent core.
The skin-side core wrap sheet is configured to include a laminated structure of a skin-side layer forming a skin-facing surface and a non-skin-side layer forming a non-skin-facing surface, and the skin-side layer is mainly composed of thermoplastic fibers. , The non-skin side layer is mainly composed of non-thermoplastic hydrophilic fibers.
An absorbent article in which a plurality of consolidated portions that are consolidated in the thickness direction are scattered in the laminated structure, and the hydrophilic fibers are exposed on the skin-facing surface side of at least a part of the plurality of compacted portions. ..

<2>
The absorbent article according to <1>, wherein the skin-side layer has a lower hydrophilicity than the non-skin-side layer in a portion of the skin-side core wrap sheet other than the consolidated portion.
<3>
Of the plurality of compacted portions existing in the laminated structure, the consolidated portion in which the hydrophilic fibers are exposed on the skin-facing surface side accounts for 50% or more, preferably 80% or more. The absorbent article according to 1> or <2>.
<4>
The plurality of compacted portions are arranged at predetermined intervals in both the vertical direction and the horizontal direction, and the interval in the vertical direction is shorter than the interval in the horizontal direction. <1> to <3> The absorbent article according to any one of the above items.
<5>
The <1> to < The absorbent article according to any one of 4>.
<6>
The absorbent article according to any one of <1> to <5>, wherein the crotch portion has a larger total area of the compacted portion than the ventral side portion and the dorsal side portion.

<7>
The absorbent article according to any one of <1> to <6>, wherein the content of the thermoplastic fiber in the skin side layer is 80% by mass or more or 100% by mass.
<8>
The absorbent article according to any one of <1> to <7>, wherein the content of the hydrophilic fibers in the non-skin side layer is 80% by mass or more or 100% by mass.
<9>
The absorbent article according to any one of <1> to <8>, wherein the hydrophilic fiber is a cellulose fiber.
<10>
The absorbent article according to any one of <1> to <9>, wherein the hydrophilic fiber is softwood kraft pulp.
<11>
The hydrophilic fibers exposed on the skin-facing surface side of the compacted portion are continuous from the skin-facing surface side to the non-skin-facing surface side of the skin-side core wrap sheet. Any 1
Absorbent articles as described in the section.
<12>
Any one of <1> to <11>, wherein the water droplet disappearance rate of the portion of the skin side layer other than the consolidated portion is 0% or more, preferably 50% or less, and more preferably 30% or less. Absorbent articles as described in the section.
<13>
Any of the above <1> to <12>, in which the water droplet disappearance rate of the non-skin side layer other than the consolidated portion is preferably 50% or more, more preferably 80% or more, and 100% or less. Or the absorbent article according to item 1.

<14>
The absorbent article according to any one of <1> to <13>, wherein the shape of the compacted portion in a plan view is a short line segment, an oblong shape, a continuous linear shape extending in the vertical direction, or a grid shape.
<15>
The plurality of compacted portions have a circular shape, a triangular shape, a quadrangular shape, a polygonal shape of a pentagon or more, a circular shape or an elliptical shape, respectively, and are arranged in a staggered manner. The absorbent article according to any one of <13>.
<16>
The number of the compacted portions per unit area is such that a part of the skin-side core wrap sheet in the lateral direction (central portion in the lateral direction) is larger than other portions in the same direction (both ends in the lateral direction). The absorbent article according to any one of <15>.
<17>
The item according to any one of <1> to <13>, wherein each of the plurality of compacted portions has a linear shape extending in the vertical direction and is intermittently arranged at predetermined intervals in the horizontal direction. Absorbent article.

<18>
The ratio of the total area of the consolidated portion in the inseam to the total area of the consolidated portion in the ventral side or the dorsal side is preferably larger in the former than in the latter, and is preferably in the former / latter. The absorbent article according to any one of <1> to <17>, which is 1.5 or more, more preferably 2 or more, and preferably 5 or less, still more preferably 3 or less.
<19>
The total area of the compacting portion in the crotch portion is preferably 750 mm ² or more, more preferably 1500 mm ² or more, and, preferably 6000 mm ² or less, more preferably 3000 mm ² or less wherein <1> to the <18> The absorbent article according to any one item.
<20>
The total area of the consolidated portion on the ventral side and the total area of the consolidated portion on the dorsal side are preferably 500 mm ² or more, more preferably 1000 mm ² or more, and preferably 5000 mm ² or less, respectively. The absorbent article according to any one of <1> to <19>, wherein is 2300 mm ^{2 or less.}

<21>
The fineness of the thermoplastic fiber is preferably 0.7 dtex or more, more preferably 1.0 dtex or more, and preferably 4.4 dtex or less, still more preferably 2.2 dtex or less. The absorbent article according to any one item.
<22>
The thickness of the hydrophilic fiber is the diameter when the cross-sectional shape in the direction orthogonal to the length direction of the hydrophilic fiber is circular, and the length of the long axis when the cross-sectional shape is elliptical or flat. The absorbent article according to any one of <1> to <21>, preferably 50 μm or less, more preferably 30 μm or less.
<23>
The item according to any one of <1> to <22>, wherein the fiber length of the hydrophilic fiber is preferably 1 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, further preferably 5 mm or less. Absorbent article.
<24>
The basis weight of the skin-side layer is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, and preferably 20 g / m ² or less, still more preferably 15 g / m ² or less. The absorbent article according to any one of <23>.
<25>
The skin-side core wrap sheet is formed by laminating the skin-side layer raw fabric sheet (preferably non-woven fabric) and the non-skin-side layer raw fabric sheet (preferably paper).
The basis weight of the non-skin side layer is preferably 10 g / m ² or more, more preferably 13 g / m ² or more, and preferably 30 g / m ² or less, still more preferably 20 g / m ² or less. > To the absorbent article according to any one of <24>.
<26>
Further, the non-skin side core wrap sheet that covers the non-skin facing surface of the absorbent core is provided, and the non-skin side core wrap sheet has the same composition as the skin side core wrap sheet. 25> The absorbent article according to any one item.

1 Deployable disposable diaper (absorbent article)
2 Front sheet 3 Back sheet 4 Absorber 40 Absorbent core 41 Skin side core wrap sheet 41a Skin side core wrap sheet skin facing surface 41b Skin side core wrap sheet non-skin facing surface 42 Skin side layer 43 Non-skin side layer 44 Thermoplastic fiber 45 Non-thermoplastic hydrophilic fiber 46 Compressed part 47 Non-compacted part 49 Non-skin side core wrap sheet 1F Ventral side 1M Inseam 1R Back side X Vertical direction Y Lateral direction

Claims (6)

It has a vertical direction corresponding to a direction extending from the ventral side of the wearer to the dorsal side via the crotch part and a lateral direction orthogonal to the vertical direction, and the crotch part arranged in the crotch part and the abdomen extending before and after the crotch part. An absorbent article having side and dorsal portions and comprising a liquid-retaining absorbent core and a skin-side core wrap sheet covering the skin-facing surface of the absorbent core.
The skin-side core wrap sheet is configured to include a laminated structure of a skin-side layer forming a skin-facing surface and a non-skin-side layer forming a non-skin-facing surface, and the skin-side layer is mainly composed of thermoplastic fibers. , The non-skin side layer is mainly composed of non-thermoplastic hydrophilic fibers.
An absorbent article in which a plurality of consolidated portions that are consolidated in the thickness direction are scattered in the laminated structure, and the hydrophilic fibers are exposed on the skin-facing surface side of at least a part of the plurality of compacted portions. .. The absorbent article according to claim 1, wherein the skin-side layer has a lower hydrophilicity than the non-skin-side layer in a portion of the skin-side core wrap sheet other than the consolidated portion. The absorbability according to claim 1 or 2, wherein the ratio of the consolidated portion in which the hydrophilic fibers are exposed on the skin facing surface side to the plurality of consolidated portions existing in the laminated structure is 50% or more. Goods. Any of claims 1 to 3, wherein a plurality of the compacted portions are arranged at predetermined intervals in both the vertical direction and the horizontal direction, and the interval in the vertical direction is shorter than the interval in the horizontal direction. The absorbent article according to item 1. Claims 1 to 3 in which the consolidated portion extends in the vertical direction, or the non-consolidated portion sandwiched between the two or more consolidated portions in the skin-side core wrap sheet extends in the vertical direction. The absorbent article according to any one item. The absorbent article according to any one of claims 1 to 5, wherein the crotch portion has a larger total area of the compacted portion than the ventral side portion and the dorsal side portion.

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