WO2022118902A1 - 積層体及び吸収性物品 - Google Patents
積層体及び吸収性物品 Download PDFInfo
- Publication number
- WO2022118902A1 WO2022118902A1 PCT/JP2021/044169 JP2021044169W WO2022118902A1 WO 2022118902 A1 WO2022118902 A1 WO 2022118902A1 JP 2021044169 W JP2021044169 W JP 2021044169W WO 2022118902 A1 WO2022118902 A1 WO 2022118902A1
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- WIPO (PCT)
- Prior art keywords
- sheet
- water
- region
- liquid
- absorbent resin
- Prior art date
Links
- 239000002250 absorbent Substances 0.000 title claims abstract description 150
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Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
Definitions
- the present invention relates to a laminate and an absorbent article. More specifically, the present invention relates to a laminate having an improved liquid permeation rate and an absorbent article using the same.
- the absorbent layer that absorbs the liquid For body fluid-absorbing articles such as paper diapers, urine pads, and sanitary napkins, the absorbent layer that absorbs the liquid, the liquid-permeable surface sheet arranged on the side in contact with the body, and the side opposite to the side in contact with the body. Consists of a laminate containing a liquid impermeable back sheet arranged in.
- One of the essential characteristics representing the performance of a body fluid-absorbing article is the liquid absorption rate. So far, various improvements have been made to body fluid-absorbing articles so that liquids can be absorbed more quickly.
- Patent Document 1 has a water-permeable front surface sheet facing the body side, a back surface side sheet facing the clothes side, and a function of being encapsulated in the front surface side sheet and the back surface side sheet to absorb body fluids.
- an absorbent article provided with a liquid-absorbent core the fiber density on the side facing the liquid-absorbent core is higher than the fiber density on the side facing the surface-side sheet between the surface-side sheet and the liquid-absorbent core.
- An absorbent article provided with a large body fluid permeable sheet (second sheet) has been proposed, and according to this absorbent article, the body fluid that has passed through the surface side sheet and reached the upper surface of the body fluid permeable sheet has a fiber density. It has been shown that it moves so as to be guided to the higher gradient side (liquid absorbing core side), so that it is absorbed quickly.
- an object of the present invention is to provide a laminate useful for an absorbent article that exhibits an excellent absorption rate even when exposed to a plurality of liquids.
- Item 1 A laminate comprising a liquid-permeable first sheet, a second sheet, and a water-absorbent resin layer interposed between the first sheet and the second sheet.
- the surface of the first sheet on the side of the water-absorbent resin layer includes a highly wettable region having a shape having a longitudinal direction and a low wettability region, and the contact angle with respect to formamide in the highly wettable region is the low.
- Item 2. The laminate according to Item 1, wherein the highly wettable region forms a recess.
- the laminate according to Item 1 wherein the highly wettable region and the low wettability region are flush with each other.
- Item 4. Items 1 to 3 in which the low-wetting region has a shape having a longitudinal direction, and a plurality of the high-wetting region and the low-wetting region are alternately arranged in the lateral direction of those regions. The laminate described in Crab. Item 5.
- Item 4. The laminate according to Item 4, wherein a plurality of the highly wettable regions and the low wettability regions are arranged in parallel.
- the laminated body has a shape having a longitudinal direction, and has a shape.
- Item 2. The laminate according to any one of Items 1 to 5, wherein the highly wettable region extends in a direction including the longitudinal direction of the laminate.
- Item 7. Item 6. The laminate according to Item 6, wherein the highly wettable region extends substantially parallel to the longitudinal direction of the laminate.
- Item 8. Item 6. The item 1 to 7, wherein the water-absorbent resin layer is a multi-layer having a first water-absorbent resin layer, a liquid-permeable intermediate layer, and a second water-absorbent resin layer in this order. Laminated body.
- Item 9. Item 2. The laminate according to any one of Items 1 to 8, wherein the first sheet is made of resin fiber.
- Item 10. Item 9. The laminate according to Item 9, wherein the resin is polyolefin.
- Item 11. An absorbent article comprising the laminate according to any one of Items 1 to 10.
- a laminate useful for an absorbent article that exhibits an excellent absorption rate even when exposed to a plurality of liquids.
- the cross-sectional view of the 1st Embodiment of the laminated body of this invention is shown schematically.
- An exploded view of a part of the laminated body of FIG. 1 is schematically shown.
- the state in which the laminate of FIG. 1 was first exposed to liquid during use is schematically shown in an exploded view as in FIG.
- Some examples of the shape of the highly wettable region are schematically shown.
- Some examples of the shape of the highly wettable region when the laminate has a longitudinal direction are shown schematically.
- the liquid-permeable first sheet in the second embodiment of the laminated body of the present invention is schematically shown.
- the liquid-permeable first sheet in the third embodiment of the laminated body of the present invention is schematically shown.
- a cross-sectional view of an example of the fourth embodiment of the laminated body of the present invention is schematically shown.
- the cross-sectional view of the 5th Embodiment of the laminated body of this invention is shown schematically.
- a specific example of the shape of the highly wettable region is shown.
- a specific example of the shape of the highly wettable region is shown.
- a specific example of the shape of the highly wettable region is shown.
- the laminate of the present invention is a laminate including a liquid-permeable first sheet, a second sheet, and a water-absorbent resin layer interposed between the first sheet and the second sheet.
- the surface of the first sheet on the side of the water-absorbent resin layer includes a highly wettable region having a shape having a longitudinal direction and a low wettability region, and the contact angle with respect to formamide in the highly wettable region is the low wettability region. It is characterized by being 10 ° or more smaller than the contact angle with formamide in the sex region.
- FIG. 1 schematically shows a cross-sectional view of a first embodiment of the laminated body of the present invention.
- the laminate 10 shown in FIG. 1 includes a liquid-permeable first sheet 20, a second sheet 30, and a water-absorbent resin layer 40 interposed between the first sheet 20 and the second sheet 30.
- the stacking direction of the laminated body 10 is also referred to as “stacking direction LMD10”.
- FIG. 2 schematically shows an exploded view of a part of the laminated body 10.
- the surface S2 on the water-absorbent resin layer 40 side of the first sheet 20 includes a highly wettable region 21 having a longitudinal LD21 and a low wettability region 22.
- the highly wettability region 21 is recessed, it forms a recess extending in the longitudinal direction LD 21.
- the high-wetting region 21 has a relatively higher wettability than the low-wetting region 22, and specifically, the contact angle with respect to formamide in the high-wetting region 21 is the formamide in the low-wetting region 22. It is configured to be 10 ° or more smaller than the contact angle with respect to. From the viewpoint of further improving the absorption rate for multiple liquid exposures, the difference obtained by subtracting the contact angle for formamide in the low wetting region 22 from the contact angle for formamide in the high wetting region 21 is preferably 15 ° or more. , More preferably 20 ° or more, still more preferably 25 ° or more, still more preferably 30 ° or more, still more preferably 35 ° or more. The upper limit of the range of the difference is not particularly limited and may vary depending on the material of the first sheet 20 and / or the treatment for different wettability, and examples thereof include 60 ° or less, 50 ° or less, or 40 ° or less. ..
- the contact angle of the highly wettable region 21 with respect to formamide include 95 ° or less, and are preferably 93 ° or less, more preferably 93 ° or less, from the viewpoint of further improving the absorption rate for multiple liquid exposures. 90 ° or less, more preferably 80 ° or less, still more preferably 76 ° or less, still more preferably 73 ° or less.
- the lower limit of the contact angle range of the high wettability region 21 with respect to formamide is not particularly limited, and the lower it is, the more preferable it is. 50 ° or more, 60 ° or more, or 65 ° or more can be mentioned.
- the contact angle of the low wetting region 22 with respect to formamide include 105 ° or more, and preferably 110 ° or more from the viewpoint of further improving the absorption rate for multiple liquid exposures.
- the temperature is preferably 125 ° or less, more preferably 120 ° or less, still more preferably 115 ° or less.
- the treatment for different wettability on the surface S2 of the first sheet 20 is not particularly limited regardless of physical treatment or chemical treatment.
- examples of the physical treatment for enhancing wettability include surface smoothing treatment, and examples of the surface smoothing treatment include melt solidification and the like.
- Chemical treatments that enhance wettability include the application and / or impregnation of hydrophilic components.
- one treatment may be performed alone, or two or more treatments (for example, physical treatment and chemical treatment) may be combined.
- a physical treatment is preferable, a surface smoothing treatment is more preferable, and a melt solidification is more preferable. Be done.
- the highly wettable region 21 forming the concave portion of the present embodiment forms a melt-solidified portion.
- the highly wettable region 21 forming the concave portion of the present embodiment is formed by using the heat seal embossing method to form the highly wettable region with respect to the surface S2 of the sheet before the treatment of the first sheet 20. It can be done by pressing while melting the place to be.
- FIG. 3 is an exploded view of the laminate 10 in a state of being first exposed to liquid during use (hereinafter, the laminate 10 in this state is also referred to as “laminate 10 ′”) in the same manner as in FIG. Shown schematically in.
- the laminate 10 is exposed to liquid from the surface of the first sheet 20 opposite to the surface S2, and the liquid moves in the stacking direction LMD 10 to pass through the liquid-permeable first sheet 20 and is a water-absorbent resin.
- the water-absorbent resin layer 40 that reaches the layer 40 and is absorbed by the water-absorbent resin constituting the water-absorbent resin layer 40 (hereinafter, the water-absorbent resin layer 40 that has absorbed the first exposed liquid is particularly referred to as "water-absorbent resin layer 40'". Also described).
- the liquid that has passed through the first sheet 20 and reached the surface S2 has a higher wettability region than the low wettability region 22 due to the difference in wettability between the high wettability region 21 and the low wettability region 22.
- the portion 41 facing the high wettability region 21 expands more than the portion 42 facing the low wettability region 22.
- the larger inflated portion 41 corresponds to the shape having the longitudinal LD21 of the highly wettable region 21 and forms a shape having the same longitudinal LD21, that is, a ridge (hereinafter, the more inflated portion 41). It is also described as “convex 41", and the portion 42 which is not expanded to the size of the convex 41 and is lowered is also described as “concave 42").
- the liquid that has passed through the liquid-permeable first sheet 20 and reached the water-absorbent resin layer 40' has a recess 42 along the longitudinal direction of the ridge 41. Flow. That is, when the liquid absorbed by the laminated body 10'is absorbed by the water-absorbent resin layer 40'after moving in the laminating direction LMD10, it is in the plane of the laminated body 10'along the longitudinal direction LD21 of the ridge 41. Move to spread in the direction.
- the ridge 41 formed by the first liquid exposure spreads the absorbed liquid in the laminate 10'without concentrating it on the portion reaching the water-absorbent resin layer 40', thereby spreading the water-absorbent resin. Maximize the area of contact between layer 40'and the liquid. It is considered that this makes it possible to improve the absorption rate. Further, the property of not concentrating the absorbed liquid in a specific place may contribute to reducing the amount of reversion of the liquid in the place.
- first liquid exposure and the “next liquid exposure” may be continuous or intermittent.
- FIG. 4 schematically shows some examples of the shape of the highly wettable region 21.
- the solid line represents the high wettability region 21, and the blank portion other than the solid line indicates the low wettability region 22.
- the shape of the highly wettable region 21 is not limited to that shown in the first embodiment, as long as it has a shape having a longitudinal direction, as described with reference to FIG. 3, the liquid initially exposed. It is considered that the ridge 41 formed by the absorption of the above can guide the liquid to be absorbed from the next time onward so as to spread in the in-plane direction of the laminated body 10'.
- the laminated body of the present invention can be used. It is possible to show an excellent absorption rate even for multiple liquid exposures.
- the shape of the highly wettable region 21 may intersect in its extending direction (that is, in the longitudinal direction).
- FIGS. 4 (B) and 4 (C) in which two highly wettable regions 21 intersect with each other, and a plurality of highly wettable regions 21 with each other.
- FIG. 4 (G) in which is crossed is mentioned.
- the angle of intersection is not limited to that shown and is arbitrary.
- the liquid exposed from the second time onward is guided so as to spread in the in-plane direction of the laminate in a plurality of directions, so that the contact efficiency between the water-absorbent resin layer 40'and the liquid is further improved. It is preferable in that it becomes a target.
- the shape of the low-wetting region 22 may also have a longitudinal direction, and in this case, the high-wetting region 21 and the low-wetting region 22 are those regions.
- a plurality of SD21s may be alternately arranged in the short direction SD21.
- FIG. 4A in which one high-wetting region 21 is provided, the high-wetting region 21 is zigzag.
- FIG. 4 (D) provided in a shape
- FIG. 4 (E) in which a high wettability region 21 is provided in a spiral shape
- FIG. 4 (F) in which a plurality of linear high wettability regions 21 are provided in parallel.
- FIG. 4 (H) in which a plurality of wavy lines of highly wettable regions 21 are provided in parallel.
- the water-absorbent resin layer 40' that has absorbed the initially exposed liquid is deformed so that the ridges 41 are arranged on both sides of the recess 42 described with reference to FIG. It has a groove-like shape and can function as a flow path. Therefore, since the liquid exposed from the second time onward moves through the groove-shaped recess 42 along the longitudinal direction of the ridge 41 as a flow path, the diffusion of the laminated body in the in-plane direction becomes more efficient. Is preferable.
- a plurality of high wettability regions 21 and low wettability regions 22 may be arranged in parallel.
- FIG. 4 (E) in which the high-wetting region 21 is provided in a spiral shape is a linear high-wetting region.
- FIG. 4 (F) in which a plurality of 21's are provided in parallel is a linear high-wetting region.
- the groove-shaped recess 42 extends with substantially the same width, so that the liquid exposed after the second time is present. It is preferable in that it moves more quickly and the diffusion of the laminated body in the in-plane direction becomes more efficient.
- the shape of the highly wettable region 21 shown in FIG. 4 may be applied individually or in a state where two or more types of shapes are combined.
- FIG. 5 schematically shows some examples of the shape of the highly wettable region 21 when the laminated body has a shape having the LD10 in the longitudinal direction.
- the solid line represents the high wettability region 21, and the blank portion other than the solid line indicates the low wettability region 22 although the reference numeral is not shown.
- 5 (DD), FIG. 5 (FF), FIG. 5 (GG), and FIG. 5 (HH) are shown in FIGS. 4 (D), 4 (F), 4 (G), and 4 (H), respectively. ),
- This is a modified example in which the laminated body has a shape having LD10 in the longitudinal direction.
- the highly wettability region 21 is the laminate. It is preferable that it extends in the direction including the longitudinal direction LD10.
- the fact that the highly wettable region 21 extends in the "direction including the longitudinal LD10" means that the longitudinal LD10 component extends regardless of whether the extending direction of the highly wettable region 21 is parallel to the longitudinal LD10. It means that it contains.
- the "direction including the longitudinal LD10" is an arbitrary direction other than the direction perpendicular to the longitudinal LD10.
- the movement to the LD10 in the longitudinal direction becomes more efficient, so that the shape of the laminated body is effectively used. It is preferable in that it can be done.
- the highly wettable region 21 (the whole in FIG. 5 (FF) and a part thereof in FIG. 5 (GG)). ) Extends substantially parallel to the longitudinal LD10 of the laminate.
- the fact that the highly wettable region 21 extends substantially parallel to the longitudinal LD10 of the laminate means that the extending direction of the highly wettable region 21 may be offset by ⁇ 5 ° with respect to the longitudinal LD10. means.
- the plurality of parallel high-wetting regions 21 may be arranged so as to merge (cross) with each other, but preferably, as shown in FIG. 5 (FF), each other.
- the width of the highly wettable region 21 (that is, the width occupied by the highly wettable region 21 in the lateral SD21) is not particularly limited, but from the viewpoint of further improving the absorption rate or, in addition, from the viewpoint of reducing the amount of reversion. Therefore, the lower limit value is preferably 1 mm or more, more preferably 2 mm or more, further preferably 3 mm or more, still more preferably 3.5 mm or more, still more preferably 4 mm or more, and the upper limit value is preferably 10 mm or less. It is more preferably 9 mm or less, further preferably 8 mm or less, still more preferably 7 mm or less, still more preferably 6 mm or less.
- the width of the highly wettable region 21 may be generally constant or may vary within the above range in the extending direction.
- FIGS. 4 (E), 4 (F), 4 (G), 4 (H), and 5 in which a plurality of high wettability regions 21 and low wettability regions 22 are arranged in parallel.
- the spacing between the highly wettable regions 21 is not particularly limited, but the absorption rate is determined.
- the lower limit value is preferably 0.2 cm or more, more preferably 0.3 cm or more, still more preferably 0.5 cm or more, and the upper limit value thereof. Is preferably 3 cm or less, more preferably 2 cm or less, still more preferably 1.5 cm or less.
- the area occupied by the highly wettable region 21 on the surface S2 of the first sheet is not particularly limited, but from the viewpoint of further improving the absorption rate for multiple liquid exposures, or in addition, from the viewpoint of reducing the amount of reversion.
- the lower limit is preferably 30% or more, more preferably 35% or more, further preferably 40% or more, still more preferably 43% or more, and the upper limit is preferably 60% or less, more preferably 55%. Below, it is more preferably 50% or less, still more preferably 47% or less.
- FIGS. 4 and 5 can be applied not only to the above-mentioned first embodiment but also to all the embodiments described below.
- FIG. 6 schematically shows the liquid-permeable first sheet 20a in the second embodiment of the laminated body of the present invention.
- the laminated body of the second embodiment is the same as the laminated body 10 of the first embodiment, except that the first sheet 20 is changed to the first sheet 20a.
- the first sheet 20a has a highly wettable region 21 and a low wettability region 22 having a shape in which the surface S2 on the water-absorbent resin layer 40 (see FIG. 3) side has a longitudinal LD21.
- the first sheet 20a used in the present embodiment is configured such that the high wettability region 21 and the low wettability region 22 are flush with each other. ..
- the difference in relative wettability between the high wettability region 21 and the low wettability region 22 is the same as in the first embodiment.
- the same as in the first embodiment can be mentioned as the treatment for making the wettability of the high wettability region 21 and the low wettability region 22 different.
- the contents considered as a mechanism showing an excellent absorption rate even when exposed to a plurality of liquids are the same as those in the first embodiment.
- FIG. 7 schematically shows the liquid-permeable first sheet 20b in the third embodiment of the laminated body of the present invention.
- the laminated body of the second embodiment is the same as the laminated body 10 of the first embodiment, except that the first sheet 20 is changed to the first sheet 20b.
- the surface S2 on the water-absorbent resin layer 40 (see FIG. 3) side has the same high wettability region 21 and low wettability as the first sheet 20 of the first embodiment.
- the region 22 is formed, the surface opposite to the surface S2 has a reversible specification having the same configuration.
- the first sheet 20b of the present embodiment is performed by using a heat seal embossing method and pressing both sides of the sheet before the treatment of the first sheet 20b while melting a place where a highly wettable region should be formed. It can be formed by.
- a high-wetting region and a low-wetting region which are liquid-permeable and have a shape having a longitudinal direction, similar to the above-mentioned liquid-permeable first sheet, are provided.
- a sheet is used which is configured such that the contact angle with respect to formamide in the highly wettable region is smaller than the contact angle with formamide in the low wettability region by 10 ° or more. All of the above-mentioned cross-sectional shapes and the features of the shape of the highly wettable region 21 described with respect to the liquid-permeable first sheet also apply to the second sheet 30c used in the present embodiment.
- FIG. 8 schematically shows a cross-sectional view of an example of the fourth embodiment of the laminated body of the present invention.
- the laminated body 10c shown in FIG. 8 has a reversible specification in which the same sheet as the first sheet 20 is used as the second sheet 30c, and the shape and position of the highly wettable region in the second sheet 30c are the first. It corresponds to the shape and position of the highly wettable region on the sheet 20.
- the shape and position of the highly wettable region in the second sheet 30c do not have to correspond to the shape and position of the highly wettable region in the first sheet 20.
- the first sheets 20a and 20b shown in FIGS. 6 and 7, respectively may be used instead of the first sheet 20.
- the second sheet 30c has the characteristics described above as the first sheet, the cross-sectional shape and / or the shape of the highly wettable region 21 is the first. A sheet different from 1 sheet 20 may be used.
- FIG. 9 schematically shows a cross-sectional view of a fifth embodiment of the laminated body of the present invention.
- the water-absorbent resin layer 40 of the laminated body 10c shown in FIG. 8 further includes a liquid-permeable intermediate layer, whereby the first water-absorbent resin layer 45 and the liquid-permeable intermediate layer are formed. It is a form in which a plurality of layers having 50 and a second water-absorbent resin layer 46 are provided in this order.
- the adhesive layer is between the first sheet 20 and the first water-absorbent resin layer 45, and between the second sheet 30c and the second water-absorbing layer. It can be interposed between the sex resin layer 46 and the resin layer 46.
- laminated body 10d all the embodiments described as the modified examples of the laminated body 10c can be applied as modified examples.
- each component of the laminate The material and thickness of each component constituting the laminate of the present invention are not particularly limited, and the material and thickness capable of each component having the above-mentioned characteristics are appropriately selected. The following contents can be applied in common to all the above-described embodiments, except when a specific embodiment is particularly mentioned.
- the first sheet is not particularly limited as long as it is liquid permeable and can be provided with the above-mentioned predetermined high wettability region and low wettability region.
- the form of the first sheet is particularly limited as long as it has a space or a hole communicating with each other in the thickness direction and the space or the hole has a size that does not allow the water-absorbent resin constituting the water-absorbent resin layer to easily pass through.
- Examples of the form of the first sheet include non-woven fabrics, woven fabrics, and porous sheets. Among these forms, the viewpoint of further improving the absorption rate for multiple liquid exposures, or in addition to the amount of reversion. From the viewpoint of reduction, a non-woven fabric is preferable.
- the form of the non-woven fabric is not particularly limited, and examples thereof include air-through non-woven fabrics, point-bonded non-woven fabrics, spunbonded non-woven fabrics, and spunlaced non-woven fabrics.
- air-through non-woven fabrics are preferable from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion.
- the material of the first sheet includes polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN), and polyamides such as nylon.
- polyolefins such as polyethylene (PE) and polypropylene (PP)
- PET polyethylene terephthalate
- PET polytrimethylene terephthalate
- PEN polyethylene naphthalate
- polyamides such as nylon.
- resins such as rayon. These resins may be used alone or in combination of two or more.
- the material of the first sheet includes cotton, silk, linen, and pulp (cellulose) in addition to the above-mentioned resin fibers (synthetic resin fibers). Natural fibers such as are also mentioned. These fibers may be used alone or in combination of two or more.
- resin fibers are preferably mentioned, and polyolefin fibers are more preferable, from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion. ..
- the first sheet is made of resin fiber, all the constituent materials (100% by mass) of the first sheet may be resin, but other constituent materials (for example, cotton or silk) are 20% by mass or less. It may contain 10% by mass or less, or 5% by mass or less.
- the texture of the first sheet is not particularly limited, but the lower limit is preferably 10 g / m from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion. 2 or more, more preferably 15 g / m 2 or more, further preferably 20 g / m 2 or more, still more preferably 24 g / m 2 or more, and the upper limit thereof is preferably 30 g / m 2 or less, more preferably 15 to It is 28 g / m 2 , more preferably 20 to 28 g / m 2 , and even more preferably 24-26 g / m 2 .
- the thickness of the first sheet is not particularly limited, but the lower limit is preferably 0.04 mm from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion.
- the above is more preferably 0.1 mm or more, further preferably 0.2 mm or more, particularly preferably 0.25 mm or more, and the upper limit thereof is preferably 0.6 mm or less, more preferably 0.45 mm or less, still more preferably. Is 0.4 mm or less, particularly preferably 0.35 mm or less.
- the thickness of the first sheet is the thickness of the portion corresponding to the low wettability region when the highly wettable region of the first sheet forms a recess as in the first, third to fifth embodiments. Say.
- the thickness of the portion corresponding to the low wettability region of the first sheet is set to 1.
- the ratio of the thickness of the portion corresponding to the highly wettable region preferably 0. 5 or less, more preferably 0.4 or less, still more preferably 0.38 or less, still more preferably 0.35 or less.
- the lower limit of the ratio range is not particularly limited, and examples thereof include 0.2 or more or 0.3 or more.
- Water-absorbent resin layer As the material of the water-absorbent resin layer (that is, the water-absorbent resin), a resin that can absorb water and has a property of swelling by absorbing water, that is, generally a highly water-absorbent resin (SAP). ) Is not particularly limited as long as it is called.
- SAP highly water-absorbent resin
- water-absorbent resin examples include a hydrolyzate of a starch-acrylonitrile graft copolymer, a neutralized product of a starch-acrylic acid graft polymer, a saponified product of a vinyl acetate-acrylic acid ester copolymer, and an acrylic acid moiety.
- examples thereof include crosslinked products of Japanese polymers and water-absorbent resins such as partially neutralized polyacrylic acid. These water-absorbent resins may be used alone or in combination of two or more.
- the water-absorbent resin layer includes the first water-absorbent resin layer 45 and the second water-absorbent resin layer 46 as in the fifth embodiment, the first water-absorbent resin layer 45 and the second water-absorbent resin layer 45 are included.
- the same water-absorbent resin may be used for the sex resin layer 46, or different water-absorbent resins may be used.
- a crosslinked product of a partially neutralized acrylic acid polymer is preferable from the viewpoint of further improving the absorption rate for multiple liquid exposures.
- the degree of neutralization of the crosslinked product of the partially neutralized acrylic acid polymer is, for example, 50 mol% or more, preferably 60 to 90 mol%, and more preferably 70 to 80 mol%.
- a method for synthesizing a crosslinked product of a partially neutralized acrylic acid polymer is known, and specific examples thereof include a reverse phase suspension polymerization method and an aqueous solution polymerization method.
- the thickness of the water-absorbent resin layer is not particularly limited, but is, for example, 50 to 1200 g / m 2 , preferably 100 to 900 g / m 2 per 1 m 2 of the laminated surface of the laminated body (that is, the surface perpendicular to the laminating direction LMD 10). , More preferably 150 to 500 g / m 2 , still more preferably 200 to 400 g / m 2 , and even more preferably 250 to 350 g / m 2 .
- the thickness of the water-absorbent resin layer is the thickness of the water-absorbent resin layer 40 when the water-absorbent resin layer is a single layer (that is, the water-absorbent resin layer 40) as shown in the first and fourth embodiments. Refers to the thickness, and when the water-absorbent resin layer is a plurality of layers (for example, the first water-absorbent resin layer 45 and the second water-absorbent resin layer 46) as shown in the fifth embodiment, the first water-absorbent resin layer is used. It refers to the sum of the thicknesses of the resin layer 45 and the second water-absorbent resin layer 46.
- the mass ratio of the water-absorbent resin used in each of the first water-absorbent resin layer 45 and the second water-absorbent resin layer 46 of the fifth embodiment includes 90/10 to 30/70, preferably 80/20 to 40/60.
- the amount of physiological saline absorbed by the water-absorbent resin is not particularly limited, but is preferably 30 to 75 g / g, more preferably 40 to 70 g / g, from the viewpoint of absorbing a larger amount of liquid and preventing the gel blocking phenomenon. More preferably, it is 50 to 65 g / g, and more preferably 60 to 63 g / g.
- the amount of the water-absorbent resin retained in the physiological saline solution is not particularly limited, but is preferably 30 to 55 g / g, more preferably 35 to 50 g / g, from the viewpoint of absorbing a larger amount of liquid and preventing the gel blocking phenomenon. More preferably, it is 40 to 45 g / g.
- the physiological saline water absorption rate of the water-absorbent resin is not particularly limited, but is preferably 25 to 80 seconds from the viewpoint of further improving the absorption rate of multiple liquid exposures or, in addition, reducing the amount of reversion. , More preferably 28 to 70 seconds, still more preferably 30 to 60 seconds, even more preferably 35 to 50 seconds, even more preferably 38 to 45 seconds, and particularly preferably 40 to 42 seconds.
- the medium particle size of the water-absorbent resin is not particularly limited, but is preferably 100 to 600 ⁇ m from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion. It is preferably 200 to 500 ⁇ m, more preferably 300 to 400 ⁇ m, and even more preferably 350 to 380 ⁇ m.
- Examples of the second sheet include a liquid-permeable sheet and an impermeable sheet.
- the second sheet in the case of a liquid-permeable sheet is a sheet selected from those used as the first sheet, and does not have a predetermined high-wetting area and low-wetting area in the first sheet.
- a sheet having the same form and material as the first sheet can be mentioned.
- the first sheet and the second sheet may be the same or different.
- the adhesive resin composition used for the adhesive layer is not limited as long as the water-absorbent resin and the first sheet can be adhered to each other, and can be appropriately selected by those skilled in the art. Since the laminate of the present invention is used for absorbing an aqueous liquid, a preferred adhesive composition includes a hot melt adhesive composition that is stable against an aqueous solvent.
- the liquid-permeable intermediate layer 50 used in the fifth embodiment divides the first water-absorbent resin layer 45 and the second water-absorbent resin layer 46, assists the diffusion of the liquid absorbed by the laminate 10d, and absorbs water. It can be provided for the purpose of temporary water retention effect until the sex resin absorbs the liquid.
- the material of the liquid-permeable intermediate layer is not particularly limited as long as it is liquid-permeable.
- the form of the liquid-permeable intermediate layer is such that it has a space or a hole communicating with each other in the thickness direction and the space or the hole has a size that does not allow the water-absorbent resin constituting the water-absorbent resin layer to easily pass through.
- the liquid permeable intermediate layer include non-woven fabrics, woven fabrics and porous sheets. Among these forms, a non-woven fabric is preferable from the viewpoint of further improving the absorption rate for multiple liquid exposures, or in addition, reducing the amount of reversion.
- the form of the non-woven fabric is not particularly limited, and examples thereof include air-through non-woven fabrics, point-bonded non-woven fabrics, spunbonded non-woven fabrics, and spunlaced non-woven fabrics.
- air-through non-woven fabrics are preferable from the viewpoint of further improving the absorption rate for multiple liquid exposures, or in addition, reducing the amount of reversion.
- the same material as that mentioned as the material of the first sheet can be used.
- the basis weight of the liquid-permeable intermediate layer is not particularly limited, but is preferably 20 to 60 g / m from the viewpoint of further improving the absorption rate for multiple liquid exposures or, in addition, reducing the amount of reversion. 2 , more preferably 30 to 55 g / m 2 , still more preferably 40 to 50 g / m 2 , and even more preferably 43 to 47 g / m 2 .
- the thickness of the liquid-permeable intermediate layer is not particularly limited, but is preferably 0.5 to 5 mm from the viewpoint of further improving the absorption rate for multiple liquid exposures, or in addition, reducing the amount of reversion. , More preferably 1 to 4 mm, still more preferably 2 to 3 mm.
- the method for producing the laminate of the present invention is not particularly limited, but for example, it can be produced by the following method.
- the water-absorbent resin is applied to either the surface S2 of the first sheet or the surface of the second sheet. Is sprayed to laminate a water-absorbent resin layer, and any one of the surface S2 of the first sheet and the surface of the second sheet is laminated, and the peripheral edges of the first sheet and the second sheet are joined as necessary (for example,). It can be manufactured by heat-bonding (heat crimping, etc.).
- the laminated bodies 10 and 10c have an adhesive layer (not shown) and the adhesive layer is laminated on both the surfaces S2 of the first sheet and the surface of the second sheet, the first sheet An adhesive is applied to the surface S2 and the surface of the second sheet to laminate the adhesive layer, and the water-absorbent resin is sprayed on either the adhesive layer on the first sheet or the adhesive layer on the second sheet.
- the water-absorbent resin layer is laminated, and one of the adhesive layer on the first sheet and the adhesive layer on the second sheet is laminated, and the peripheral edges of the first sheet and the second sheet are joined as necessary. It can be produced by (for example, heat crimping or the like).
- the laminated bodies 10 and 10c have an adhesive layer laminated on the surface of either the surface S2 of the first sheet or the second sheet, the surface S2 of the first sheet and the second sheet It can be produced in the same manner as above except that the adhesive layer is not laminated on either surface.
- the water-absorbent resin is sprayed on either the surface S2 of the first sheet 20 or the surface of the second sheet 30c to absorb the first water.
- the laminated material A in which either the sex resin layer 45 or the second water-absorbent resin layer 46 is laminated, and the liquid-permeable intermediate layer 50 is further laminated, and the surface S2 of the first sheet or the surface of the second sheet.
- a laminated material B in which either the first water-absorbent resin layer 45 or the second water-absorbent resin layer 46 is laminated is produced by spraying the water-absorbent resin on the other, and the laminated material A is used as the laminated material B. It can be produced by laminating and, if necessary, collectively joining the peripheral edges of the first sheet, the liquid-permeable intermediate layer 50 and the second sheet (for example, heat crimping or the like).
- the laminated body 10d has an adhesive layer (not shown)
- an adhesive is applied to either the surface S2 of the first sheet 20 or the surface of the second sheet 30c to laminate the adhesive layer, and the water-absorbent resin is sprayed.
- one of the first water-absorbent resin layer 45 and the second water-absorbent resin layer 46 is laminated, and the liquid-permeable intermediate layer is further laminated with the laminated material A, and the surfaces S2 and the second of the first sheet.
- An adhesive is applied to either one of the surfaces of the sheet to laminate the adhesive layer, and then the water-absorbent resin is sprayed to spray the water-absorbent resin layer 45 or the second water-absorbent resin layer 46.
- the laminated material B and the laminated material B are laminated, the laminated material A is laminated on the laminated material B, and the peripheral edges of the first sheet, the liquid permeable intermediate layer 50, and the second sheet are collectively bonded (for example, heated) as needed. It can be manufactured by crimping (such as crimping).
- the above-mentioned laminate of the present invention functions as an absorber that exhibits an excellent absorption rate even when exposed to a plurality of liquids. Therefore, since the laminate of the present invention is useful for an absorbent article, the present invention also provides an absorbent article containing the laminate.
- the absorbent article is not particularly limited, but preferably includes an absorbent article that needs to absorb the liquid a plurality of times.
- the liquid may be any liquid containing water. More specific examples of absorbent articles include disposable diapers, urine pads, menstrual napkins, pet sheets, food drip sheets, water blocking materials for power cables, and the like.
- the first-stage monomer aqueous solution prepared above was added to a separable flask, and after stirring for 10 minutes, HLB3 sucrose stearate ester (Mitsubishi Chemical) was added to 6.62 g of n-heptane as a surfactant. Foods Co., Ltd., Ryoto Sugar Ester S-370) 0.736 g of a surfactant solution was further added, and the inside of the system was sufficiently replaced with nitrogen while stirring at a stirring speed of 500 rpm. After that, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization was carried out for 60 minutes to obtain a first-stage polymerized slurry liquid.
- HLB3 sucrose stearate ester Mitsubishi Chemical
- ⁇ Second stage polymerization reaction> In a beaker with an internal volume of 500 mL, take 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer, and while cooling from the outside, 27 mass% sodium hydroxide. After 159.0 g of an aqueous solution was added dropwise to neutralize 75 mol%, 0.090 g (0.333 mmol) of potassium persulfate was used as a water-soluble radical polymerization initiator, and ethylene glycol diglycidyl ether was used as an internal cross-linking agent. 0116 g (0.067 mmol) was added and dissolved to prepare a second-stage monomer aqueous solution.
- the entire amount of the monomer aqueous solution in the second stage is added to the polymerized slurry liquid in the first stage.
- the inside of the system was replaced with nitrogen for 30 minutes, the flask was again immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel-like polymer.
- n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dried to obtain a dried product of polymer particles.
- the polymer particles are passed through a sieve having an opening of 850 ⁇ m, and 0.2% by mass of amorphous silica (Oriental Silicas Corporation, Toxile NP-S) with respect to the mass of the polymer particles is mixed with the polymer particles. , 231.2 g of SAPa containing amorphous silica was obtained.
- Production Example 2 Synthesis of SAPb In the water-containing gel-like polymer after the second stage polymerization of Production Example 1, 257.2 g of water was extracted from the system by azeotropic distillation. The same operation as in Production Example 1 was carried out to obtain 231.2 g of SAPb.
- the first-stage monomer aqueous solution prepared above was added to a separable flask, and after stirring for 10 minutes, HLB3 sucrose stearate ester (Mitsubishi Chemical) was added to 6.62 g of n-heptane as a surfactant. Foods Co., Ltd., Ryoto Sugar Ester S-370) 0.736 g of a surfactant solution was further added, and the inside of the system was sufficiently replaced with nitrogen while stirring at a stirring speed of 500 rpm. After that, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization was carried out for 60 minutes to obtain a first-stage polymerized slurry liquid.
- HLB3 sucrose stearate ester Mitsubishi Chemical
- ⁇ Second stage polymerization reaction> In a beaker with an internal volume of 500 mL, take 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer, and while cooling from the outside, 27 mass% sodium hydroxide. After adding 159.0 g of the aqueous solution to neutralize 75 mol%, 0.129 g (0.476 mmol) of 2,2'-azobis (2-amidinopropane) dihydrochloride as a water-soluble radical polymerization initiator.
- the entire amount of the monomer aqueous solution in the second stage is added to the polymerized slurry liquid in the first stage.
- the inside of the system was replaced with nitrogen for 30 minutes, the flask was again immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel-like polymer.
- n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dried to obtain a dried product of polymer particles.
- the polymer particles are passed through a sieve having an opening of 850 ⁇ m, and 0.2% by mass of amorphous silica (Oriental Silicas Corporation, Toxile NP-S) with respect to the mass of the polymer particles is mixed with the polymer particles. , 231.2 g of SAPc containing amorphous silica was obtained.
- the cotton bag after 30 minutes was dehydrated for 1 minute using a dehydrator (manufactured by Kokusan Co., Ltd., product number: H-122) set to have a centrifugal force of 167 G, and then contained the swollen gel after dehydration.
- the mass Wc [g] of the cotton bag was measured.
- the same operation was performed without adding the water-absorbent resin particles, the empty mass Wd [g] of the cotton bag when wet was measured, and the water retention amount of the physiological saline of the water-absorbent resin particles was calculated from the following formula.
- the spunbonded nonwoven fabric was provided with a highly wettable region in the same manner as in (3-1) above.
- the obtained processed spunbonded non-woven fabric a had a high wettability region and a low wettability region flush with each other as shown in the first sheet 20a shown in FIG. (3-3-2)
- the spunbonded non-woven fabric extends at intervals of about 1.5 cm in the directions parallel to the longitudinal direction and the lateral direction of the nonwoven fabric by the method of (3-1) above, each having a width of about 5 mm.
- Highly wettable regions were provided in a grid pattern. In FIG. 11, the shaded portion indicates a highly wettable region, and the non-shaded portion indicates a low wettability region.
- the obtained processed spunbonded non-woven fabric b had a high wettability region and a low wettability region flush with each other as shown in the first sheet 20a shown in FIG. (3-3-3)
- a highly wettable region having a width of about 5 mm is formed on the spunbonded nonwoven fabric by the method of (3-1) above, extending at intervals of about 5 mm in a direction parallel to the lateral direction of the nonwoven fabric. 31 pieces were provided.
- the shaded portion indicates a highly wettable region
- the non-shaded portion indicates a low wettability region.
- the obtained processed spunbonded non-woven fabric c had a high wettability region and a low wettability region flush with each other as shown in the first sheet 20a shown in FIG.
- the thickness was measured by lightly sandwiching the low-wetting area or the high-wetting area to be measured once with a thickness measuring device (Dial Thickness Gauge JB manufactured by Ozaki Seisakusho Co., Ltd.).
- the contact angle was measured in an environment with a temperature of 25 ⁇ 2 ° C. and a humidity of 50 ⁇ 10%.
- Double-sided tape removable strong double-sided tape No. 5000NS manufactured by Nitto Denko
- the non-woven fabric for which the contact angle is to be measured was cut into a size of 25 mm ⁇ 50 mm and attached onto the metal plate with double-sided tape so as not to cause wrinkles, and a sample for measurement was prepared.
- the automatic contact angle meter (manufactured by Kyowa Surface Chemistry: DMo-601) consists of a sample mounting stage that can move up and down, a syringe section installed above it, and a scope section that allows horizontal observation of the stage. The contact angle was measured by the following procedure using such a contact angle meter. First, formamide was aspirated into the syringe (capacity 1 mL), and a measurement sample was placed on the stage portion directly below the syringe. The stage was moved upwards and a drop of formamide (2.0 ⁇ L) was brought into contact with a place where the surface of the sample was smooth, and the drop was deposited on the sample. The contact angle between the formamide droplet and the sample surface at 1 second after landing was determined by the ⁇ / 2 method.
- laminated body 5-1 Structure of laminated body First sheet, adhesive layer, first water-absorbent resin layer, liquid-permeable intermediate layer, second water-absorbent resin layer, adhesive layer, And the second sheet were laminated in this order to prepare a laminated body.
- An air-through nonwoven fabric to be a liquid-permeable intermediate layer was placed on the first water-absorbent resin layer.
- the entire first sheet, adhesive layer, first water-absorbent resin layer and liquid-permeable intermediate layer are sandwiched between release papers, and a laminating machine (Hashima Co., Ltd., Straight Liner Fussing Press, model HP-600LFS, 110 ° C., It was pressed with 0.1 MPa) to remove the release paper.
- a laminating machine Hashima Co., Ltd., Straight Liner Fussing Press, model HP-600LFS, 110 ° C., It was pressed with 0.1 MPa
- a total amount of 0.2 g of hot melt adhesive is applied to the second sheet (the same material as the first sheet) in the same manner as above, 4.5 g of SAPa obtained in Production Example 1 is uniformly sprayed, and the second water absorption is performed.
- the sex resin layer was laminated to obtain a laminate B of a second sheet and a laminate of the second water-absorbent resin layer.
- Laminated body A is laminated on the second water-absorbent resin layer of the laminated body B so that the liquid-permeable intermediate layer of the laminated body A is in contact with the second water-absorbent resin layer.
- a laminate was obtained.
- Test solution A test solution having the following composition was prepared. -Ion-exchanged water: 9865.75 g NaCl: 100.0 g ⁇ CaCl 2.2H 2 O : 3.0g ⁇ MgCl 2.6H 2 O : 6.0g -Triton X-100 (1%): 25.0 g -Edible blue No. 1 (for coloring): 0.25 g
- Score 1 The total value of the permeation rate [seconds] of 1 to 3 times was calculated, and the difference between the total value according to Examples 1 to 7 and Comparative Examples 8 and 10 and the total value according to the corresponding comparative example was obtained. Each of the differences was converted into a relative amount with the total value according to the corresponding comparative example as 100%, and the value (%) thus obtained was set as a score 1. Score 1 is an evaluation value indicating how much the total time required for absorption of the exposed liquid 1 to 3 times can be shortened with respect to the corresponding comparative example, and the larger the score 1, the more than one. It can be evaluated that the effect of improving the absorption rate with respect to multiple liquid exposures is high. The results are shown in Table 1.
Abstract
Description
項1. 透液性の第1シートと、第2シートと、前記第1シート及び前記第2シートの間に介在する吸水性樹脂層と、を含む積層体であって、
前記第1シートの前記吸水性樹脂層の側の面が、長手方向を有する形状の高濡れ性領域と、低濡れ性領域とを含み、前記高濡れ性領域におけるホルムアミドに対する接触角が、前記低濡れ性領域におけるホルムアミドに対する接触角よりも10°以上小さい、積層体。
項2. 前記高濡れ性領域が凹条を成している、項1に記載の積層体。
項3. 前記高濡れ性領域と前記低濡れ性領域とが面一である、項1に記載の積層体。
項4. 前記低濡れ性領域が長手方向を有する形状であり、前記高濡れ性領域と前記低濡れ性領域とが、それらの領域の短手方向に交互に複数配置されている、項1~3のいずれかに記載の積層体。
項5. 前記高濡れ性領域と前記低濡れ性領域とが複数並列して配置されている、項4に記載の積層体。
項6. 前記積層体が長手方向を有する形状であり、
前記高濡れ性領域が、前記積層体の長手方向を含む方向に延在する、項1~5のいずれかに記載の積層体。
項7. 前記高濡れ性領域が、前記積層体の長手方向に略平行に延在する、項6に記載の積層体。
項8. 前記吸水性樹脂層が、第1の吸水性樹脂層と、透液性中間層と、第2の吸水性樹脂層とをこの順で有する複層である、項1~7のいずれかに記載の積層体。
項9. 前記第1シートが樹脂繊維製である、項1~8のいずれかに記載の積層体。
項10. 前記樹脂がポリオレフィンである、項9に記載の積層体。
項11. 項1~10のいずれかに記載の積層体を含む、吸収性物品。
本発明の積層体は、透液性の第1シートと、第2シートと、前記第1シート及び前記第2シートの間に介在する吸水性樹脂層と、を含む積層体であって、前記第1シートの前記吸水性樹脂層の側の面が、長手方向を有する形状の高濡れ性領域と、低濡れ性領域とを含み、前記高濡れ性領域におけるホルムアミドに対する接触角が、前記低濡れ性領域におけるホルムアミドに対する接触角よりも10°以上小さいことを特徴とする。このような構造によって、本発明の積層体は、複数回の液体暴露に対しても優れた吸収速度を示すことが可能となる。以下、本発明の積層体について詳述する。
図1に、本発明の積層体の第1実施形態の断面図を模式的に示す。図1に示す積層体10は、透液性の第1シート20と、第2シート30と、第1シート20及び第2シート30の間に介在する吸水性樹脂層40と、を含む。以下において、積層体10の積層方向を「積層方向LMD10」とも記載する。なお、図示していないが、第1シート20と吸水性樹脂層40との間、及び/又は吸水性樹脂層40と第2シート30との間には、接着剤層が介在していてもよい。
図4に、高濡れ性領域21の形状のいくつかの例を挙げて模式的に示す。図4において、実線は高濡れ性領域21を表し、実線以外の空白部分は低濡れ性領域22を示す。高濡れ性領域21の形状は上記第1実施形態に示したものに限定されず、長手方向を有する形状でありさえすれば、図3を参照して説明したように、最初に暴露された液体の吸収によって形成される凸条41が次回以降に吸収する液体を積層体10’の面内方向に広げるように案内することができると考えられる。つまり、高濡れ性領域21の形状が長手方向を有する形状でありさえすれば、図4(A)に示すように高濡れ性領域21が1本であっても、本発明の積層体は、複数回の液体暴露に対しても優れた吸収速度を示すことが可能となる。
このような態様の場合、2回目以降に暴露される液体が積層体の面内方向へ移動する時に、特に長手方向LD10への移動が特に効率的となるため、積層体の形状をより一層有効利用できる点で好ましい。
図6に、本発明の積層体の第2実施形態における透液性の第1シート20aを模式的に示す。第2実施形態の積層体は、第1シート20が第1シート20aに変更されたことを除いて、上記の第1実施形態の積層体10と同様である。
図7に、本発明の積層体の第3実施形態における透液性の第1シート20bを模式的に示す。第2実施形態の積層体は、第1シート20が第1シート20bに変更されたことを除いて、上記の第1実施形態の積層体10と同様である。
本発明の第4実施形態では、第2シートとして、上述の透液性の第1シートと同様の、透液性であり、長手方向を有する形状の高濡れ性領域と低濡れ性領域とを含み、前記高濡れ性領域におけるホルムアミドに対する接触角が、前記低濡れ性領域におけるホルムアミドに対する接触角よりも10°以上小さいように構成されたシートを用いる。透液性の第1シートに関して説明した上述の断面形状及び高濡れ性領域21の形状における特徴は全て、本実施形態で用いられる第2シート30cにも適用される。
図9に、本発明の積層体の第5実施形態の断面図を模式的に示す。図9に示す積層体10dは、図8に示した積層体10cの吸水性樹脂層40がさらに透液性中間層を含むことで、第1の吸水性樹脂層45と、透液性中間層50と、第2の吸水性樹脂層46とをこの順で有する複層をなしている形態である。
本発明の積層体を構成する各構成要素の材料及び厚みとしては特に限定されず、各構成要素が上述の特徴を備えることができる材料及び厚みが適宜選択される。なお、特に特定の実施形態に言及した場合を除き、以下の内容は、上記したすべての実施形態について共通して適用することができる。
第1シートとしては、透液性であって、上述の所定の高濡れ性領域と低濡れ性領域とを備えることができるものであれば特に限定されない。
これらの形態の中でも、複数回の液体暴露にする吸収速度をより一層向上させる観点、又はそれに加えて逆戻り量を低減する観点から、好ましくは不織布が挙げられる。
なお、第1シートが樹脂繊維製である場合、第1シートの構成材料全て(100質量%)が樹脂であってもよいが、他の構成材料(例えば、綿や絹)が20質量%以下、10質量%以下、又は5質量%以下含んでいてもよい。
吸水性樹脂層の材料(つまり吸水性樹脂)としては、水を吸収可能であり、且つ水を吸収することで膨潤する特性を有している樹脂、つまり、一般的に高吸水性樹脂(SAP)と呼ばれるものであれば特に限定されない。
第2シートとしては、透液性シート及び不透液性シートが挙げられる。透液性シートである場合の第2シートとしては、第1シートとして用いられるものから選択されるシート、及び、第1シートにおける所定の高濡れ性領域及び低濡れ性領域を備えないことを除いて第1シートと同じ形態及び材料のシートが挙げられる。
接着剤層に用いる接着性樹脂組成物としては、吸水性樹脂と第1シートとを接着可能である限りにおいて限定されず、当業者が適宜選択することができる。本発明の積層体は水系の液体を吸収するために用いられるため、好ましい接着剤組成物としては水系溶剤に対して安定なホットメルト接着剤組成物が挙げられる。
第5実施形態において用いられる透液性中間層50は、第1の吸水性樹脂層45と第2の吸水性樹脂層46とを分割し、積層体10dが吸収した液体の拡散を助け、吸水性樹脂が液体を吸収するまでの一時的な保水効果を目的として設けることができる。透液性中間層の材料としては、透液性である限りにおいて特に限定されない。
本発明の積層体の作製方法としては特に限定されないが、例えば以下の方法で製造することができる。
上記の本発明の積層体は、複数回の液体暴露に対しても優れた吸収速度を示す吸収体として機能する。したがって、上記本発明の積層体は吸収性物品に有用であるため、本発明は当該積層体を含む吸収性物品も提供する。
(1-1)製造例1:SAPaの合成
<第1段目の重合反応>
還流冷却器、滴下ロート、及び窒素ガス導入管、並びに、攪拌機として、翼径5cmの4枚傾斜パドル翼を2段で有する攪拌翼を備えた内径11cm、2L容の丸底円筒型セパラブルフラスコを準備した。このフラスコに、炭化水素分散媒としてn-ヘプタン293gをとり、高分子系分散剤として無水マレイン酸変性エチレン・プロピレン共重合体(三井化学株式会社、ハイワックス1105A)0.736gを添加し、攪拌しつつ80℃まで昇温して分散剤を溶解した後、50℃まで冷却した。
内容積500mLのビーカーに水溶性エチレン性不飽和単量体として80.5質量%のアクリル酸水溶液128.8g(1.44モル)をとり、外部より冷却しつつ、27質量%の水酸化ナトリウム水溶液159.0gを滴下して75モル%の中和を行った後、水溶性ラジカル重合開始剤として過硫酸カリウム0.090g(0.333ミリモル)、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を加えて溶解し、第2段目の単量体水溶液を調製した。
製造例1の第2段目の重合後の含水ゲル状重合体において、共沸蒸留により257.2gの水を系外へ抜き出したこと以外は、製造例1と同様の操作を行い、SAPbを231.2g得た。
<第1段目の重合反応>
還流冷却器、滴下ロート、及び窒素ガス導入管、並びに、攪拌機として、翼径5cmの4枚傾斜パドル翼を2段で有する攪拌翼を備えた内径11cm、2L容の丸底円筒型セパラブルフラスコを準備した。このフラスコに、炭化水素分散媒としてn-ヘプタン293gをとり、高分子系分散剤として無水マレイン酸変性エチレン・プロピレン共重合体(三井化学株式会社、ハイワックス1105A)0.736gを添加し、攪拌しつつ80℃まで昇温して分散剤を溶解した後、50℃まで冷却した。
内容積500mLのビーカーに水溶性エチレン性不飽和単量体として80.5質量%のアクリル酸水溶液128.8g(1.44モル)をとり、外部より冷却しつつ、27質量%の水酸化ナトリウム水溶液159.0gを滴下して75モル%の中和を行った後、水溶性ラジカル重合開始剤として2,2’-アゾビス(2-アミジノプロパン)2塩酸塩0.129g(0.476ミリモル)及び過硫酸カリウム0.026g(0.096ミリモル)、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を加えて溶解し、第2段目の単量体水溶液を調製した。
(2-1)吸水量
吸水量の測定は、25℃±1℃に調節された室内で行った。500mL容のビーカーに、生理食塩水500g±0.1gを量りとり、マグネチックスターラーバー(8mmφ×30mmのリング無し)を投入し、回転数を600r/minに調節した。次に、吸水性樹脂粒子2.0gを添加して室温(25℃)で攪拌した。60分間攪拌後、質量Wb[g]を有する、目開き75μmのJIS Z 8801-1標準篩を用いて、上記混合液をろ過し、篩を水平に対して約30度の傾斜角となるように傾けた状態で、ろ物を篩上で30分間放置した。吸水した吸水性樹脂粒子と篩の質量の合計Wa[g]を測定し、下記式から吸水性樹脂粒子の生理食塩水の吸水量を算出した。結果を表1に示す。
吸水量[g/g]=(Wa-Wb)/2.0
保水量の測定は、25℃±1℃に調節された室内で行った。吸水性樹脂粒子2.0gを量り取った綿袋(メンブロード60番、横100mm×縦200mm)を内容積500mLのビーカー内に設置した。吸水性樹脂粒子の入った綿袋内に生理食塩水500gを、ママコができないように一度に注ぎ込んだ後、綿袋の上部を輪ゴムで縛り、30分静置させることで吸水性樹脂粒子を膨潤させた。30分経過後の綿袋を、遠心力が167Gとなるように設定した脱水機(株式会社コクサン製、品番:H-122)を用いて1分間脱水した後、脱水後の膨潤ゲルを含んだ綿袋の質量Wc[g]を測定した。吸水性樹脂粒子を添加せずに同様の操作を行い、綿袋の湿潤時の空質量Wd[g]を測定し、下記式から吸水性樹脂粒子の生理食塩水の保水量を算出した。結果を表1に示す。
保水量[g/g]=(Wc-Wd)/2.0
吸水速度の測定は、25℃±1℃に調節された室内で行った。100mL容のビーカーに、生理食塩水50±0.1gを量りとり、マグネチックスターラーバー(8mmφ×30mmのリング無し)を投入し、ビーカーを恒温水槽に浸漬して、液温を25±0.2℃に調節した。次に、マグネチックスターラー上にビーカーを置いて、回転数600r/minとして、生理食塩水に渦を発生させた後、吸水性樹脂粒子2.0±0.002gを、前記ビーカーに素早く添加し、ストップウォッチを用いて、吸水性樹脂の添加後から液面の渦が収束する時点までの時間(秒)を測定し、吸水性樹脂粒子の吸水速度とした。結果を表1に示す。
JIS標準篩を、上から、目開き600μmの篩、目開き500μmの篩、目開き425μmの篩、目開き300μmの篩、目開き250μmの篩、目開き180μmの篩、目開き150μmの篩、及び、受け皿の順に組み合わせた。組み合わせた最上の篩に、吸水性樹脂粒子50gを入れ、ロータップ式振とう器を用いて10分間振とうさせて分級した。分級後、各篩上に残った粒子の質量を全量に対する質量百分率として算出し粒度分布を求めた。この粒度分布に関して粒子径の大きい方から順に篩上を積算することにより、篩の目開きと篩上に残った粒子の質量百分率の積算値との関係を対数確率紙にプロットした。確率紙上のプロットを直線で結ぶことにより、積算質量百分率50質量%に相当する粒子径を中位粒子径として得た。結果を表1に示す。
以下の不織布を用意し、長手方向を有する形状(12cm×32cmの長方形)に切り出した。
・エアスルー不織布a(KNH Enterprise Co.,Ltd.、AT025―CP49―0、材料組成:PP及びPE、目付量:25g/m2)
・エアスルー不織布b(レンゴー・ノンウーブン・プロダクツ株式会社、材料組成:50%PP及び50%PE、目付量:21g/m2)
・スパンボンド不織布(旭化成株式会社、SMMS 材料組成:100%PP、目付量:12g/m2)
・エアレイド不織布(KNH Enterprise Co.,Ltd.、6190516-1A01、材料組成:PP、PE及びパルプ、目付量:40g/m2)
・スパンレース不織布(ユニ・チャーム国光ノンウーヴン株式会社、ソフロンE、材料組成:レーヨン、PET、PP及びPE、目付量:33g/m2)
エアスルー不織布aに、ヒートシーラー(富士インパルス株式会社、FI-450-5、時間設定3~6)を用い、ヒートシールエンボスの手法により、溶融固化部(エンボス部)を高濡れ性領域として形成した。具体的には、図10に示すように、不織布の長手方向と平行な方向に約5mm間隔で延在する、各々約5mm幅の高濡れ性領域(エンボス部)を11本設けた。なお、図10において、網掛部が高濡れ性領域、非網掛部が低濡れ性領域を示す。得られた加工済みエアスルー不織布aは、図7に示す第1シート20bの形態を有していた。
エアスルー不織布bに、上記(3-1)と同様にして高濡れ性領域(エンボス部)を設けた。得られた加工済みエアスルー不織布bは、図7に示す第1シート20bの形態を有していた。
スパンボンド不織布に以下の加工を行い、高濡れ性領域の形状が異なる3種の不織布を得た。
スパンボンド不織布に、上記(3-1)と同様にして高濡れ性領域を設けた。得られた加工済みスパンボンド不織布aは、図6に示す第1シート20aのように、高濡れ性領域及び低濡れ性領域が面一であった。
(3-3-2)
スパンボンド不織布に、上記(3-1)の手法で、図11に示すように、不織布の長手方向及び短手方向とそれぞれ平行な方向に約1.5cm間隔で延在する、各々約5mm幅の高濡れ性領域を格子状に設けた。なお、図11において、網掛部が高濡れ性領域、非網掛部が低濡れ性領域を示す。得られた加工済みスパンボンド不織布bは、図6に示す第1シート20aのように、高濡れ性領域及び低濡れ性領域が面一であった。
(3-3-3)
スパンボンド不織布に、上記(3-1)の手法で、図12に示すように、不織布の短手方向と平行な方向に約5mm間隔で延在する、各々約5mm幅の高濡れ性領域を31本設けた。なお、図12において、網掛部が高濡れ性領域、非網掛部が低濡れ性領域を示す。得られた加工済みスパンボンド不織布cは、図6に示す第1シート20aのように、高濡れ性領域及び低濡れ性領域が面一であった。
エアレイド不織布に、上記(3-1)と同様にして高濡れ性領域(エンボス部)を設けた。得られた加工済みエアレイド不織布は、図7に示す第1シート20bの形態を有していた。
スパンレース不織布に、上記(3-1)と同様にして高濡れ性領域(エンボス部)を設けた。得られた加工済みススパンレース不織布は、図7に示す第1シート20bの形態を有していた。
低濡れ性領域の厚み(mm)、高濡れ性領域の厚み(mm)、不織布表面積(厚みを構成する面を除く)に対する高濡れ性領域の面積率(%)、接触角(°)及び接触角差(°)を測定した。結果を表1に示す。
厚み測定器(株式会社尾崎製作所製、ダイヤルシックネスゲージJ-B)に、測定すべき低濡れ性領域又は高濡れ性領域を軽く1回挟んで厚みを測定した。
接触角の測定は温度25±2℃、湿度50±10%の環境下で行った。ステンレス製の金属板(30mm×70mm、厚さ1mm)に両面テープ(日東電工製 再剥離可能強力両面テープNo.5000NS)を貼付した。接触角を測定する不織布を25mm×50mmの大きさに裁断し、上記両面テープ付き金属板の上にしわが生じないように貼付し、測定用サンプルを準備した。
まず、前記シリンジ(容量1mL)にホルムアミドを吸引させ、シリンジ鉛直下のステージ部に測定用サンプルを載置した。ステージを上方に動かし、ホルムアミドの液滴(2.0μL)をサンプルの表面が平滑な場所に接触させ、サンプル上に液滴を着液させた。着液から1秒後の時点での前記ホルムアミド液滴とサンプル表面との接触角をθ/2法によって求めた。
(5-1)積層体の構造
第1シート、接着剤層、第1の吸水性樹脂層、透液性中間層、第2の吸水性樹脂層、接着剤層、及び第2シートがこの順で積層された積層体を作製した。
・第1の吸水性樹脂層用の吸水性樹脂粒子(実施例1~7及び比較例1~11)
・・製造例1で合成したSAPa
・・製造例2で合成したSAPb
・・製造例3で合成したSAPc
・第2の吸水性樹脂層用の吸水性樹脂粒子(実施例1~7及び比較例1~11)
・・全ての実施例及び比較例において共通して、製造例1で合成したSAPa
・・加工済みエアスルーa不織布(長手方向)
・・加工済みエアスルーb不織布(長手方向)
・・加工済みスパンボンド不織布a(長手方向)
・・加工済みスパンボンド不織布b(格子状)
・・加工済みスパンボンド不織布c(短手方向)
・・加工済みエアレイド不織布(長手方向)
・・加工済みスパンレース不織布(長手方向)
・第1シート(比較例1~7、9、11)
・・加工なしエアスルーa不織布
・・加工なしエアスルーb不織布
・・加工なしスパンボンド不織布
・・加工なしスパンボンド不織布
・・加工なしスパンボンド不織布
・・加工なしエアレイド不織布
・・加工なしスパンレース不織布
・・それぞれの実施例及び比較例において第1シートと同じ不織布
・・エアスルー不織布(広州市錦漢不織布有限公司、D45―200、目付量45g/m2、2.42mm)
・・ホットメルト接着剤(ヘンケルジャパン株式会社 軟化点96℃ TECHNOMELT DM5912)
表1に示す第1シートの短手方向および長手方向両端の外周1cmを除く領域に、ホットメルト塗工機(株式会社ハリーズ、ポンプ:Marshal150、テーブル:XA-DT、タンク設定温度:150℃、ホース内設定温度:165℃、ガンヘッド設定温度:170℃)で、全量0.2gのホットメルト接着剤を、第1シートの長手方向にそって、10mm間隔で10本塗布し、接着剤層を設けた。接着剤の塗布パターンはスパイラルストライプとした。接着剤層が設けられた上記領域に、表1に示す吸水性樹脂粒子4.5gを均一に散布し、第1の吸水性樹脂層を積層した。第1の吸水性樹脂層上に、透液性中間層となるエアスルー不織布を載置した。第1シート、接着剤層、第1の吸水性樹脂層及び透液性中間層の全体を剥離紙で挟持し、ラミネート機(株式会社ハシマ、Straight Linear Fussing Press、型式HP-600LFS、110℃、0.1MPa)を用いてプレスし、剥離紙を取り除いた。これにより、第1シート、接着剤層、第1の吸水性樹脂層及び透液性中間層の積層体Aを得た。
(6-1)試験液
以下の組成を有する試験液を調製した。
・イオン交換水:9865.75g
・NaCl:100.0g
・CaCl2・2H2O:3.0g
・MgCl2・6H2O:6.0g
・トリトン X-100(1%):25.0g
・食用青色1号(着色用):0.25g
温度25±2℃の室内において、水平の台の上に第1シートが上面となるよう積層体を配置し、トップシートとして長方形状(12cm×32cm)のエアスルー不織布(レンゴー・ノンウーブン・プロダクツ株式会社、材料組成:50%PP及び50%PE、目付量:21g/m2)を積層体上に載置した。次に、内径3cmの投入口を有する容量100mLの液投入用シリンダー(両端が開口した円筒)をトップシートの中心部に置いた。続いて、あらかじめ25±1℃に調整した試験液80mLを鉛直方向上部からシリンダー内へ一度に投入した。ストップウォッチを用いて、投入開始から、試験液がシリンダー内から完全に消失するまでの吸収時間を測定した。この操作を30分間隔で更に2回(合計3回)行い、各回の吸収時間及び吸収時間の合計値を浸透速度[秒]として得た。得られた浸透速度の値に基づいて、複数回の液体暴露に対する吸収速度の向上効果を評価する3種類のスコアを導出した。以下において、高濡れ性領域を設けた第1シートを用いて作製した実施例1~7及び比較例8、10に対し、高濡れ性領域を設けなかったことを除いてそれぞれ同じ条件で作製した比較例1~7、9、11を、「対応する比較例」と記載する。
1~3回の浸透速度[秒]の合計値を算出し、実施例1~7及び比較例8、10による当該合計値と、対応する比較例による当該合計値との差分を求め、得られた差分それぞれを、対応する比較例による当該合計値を100%とする相対量に変換し、このようにして得られた値(%)をスコア1とした。スコア1は、1~3回の暴露された液体の吸収に要した総時間を、対応する比較例に対してどれだけの割合短縮できたかを示す評価値であり、スコア1が大きいほど、複数回の液体暴露に対する吸収速度の向上効果が高いと評価できる。結果を表1に示す。
1回目の浸透速度[秒]を1とした場合の2回目の浸透速度[秒]の相対値を相対速度の2回目延長率として算出し、対応する比較例による当該2回目延長率を1とした場合の実施例1~7及び比較例8、10による当該2回目延長率の相対値を求め、これをスコア2とした。相対速度の2回目延長率は、2回目に暴露された液体を吸収するのに、1回目よりもどの程度余分に時間がかかったかを示している。スコア2は、2回目に暴露された液体の吸収に余分にかかる時間をどの程度抑制できたかを示しており、スコア2が1未満の場合、2回目の液体吸収時にその抑制効果が奏されたと評価でき、スコア2が小さいほど、2回目の液体吸収時におけるその抑制効果が高いと評価できる。結果を表1に示す。
1回目の浸透速度[秒]を1とした場合の3回目の浸透速度[秒]の相対値を相対速度の3回目延長率として算出し、対応する比較例による当該3回目延長率を1とした場合の実施例1~7及び比較例8、10による当該3回目延長率の相対値を求め、これをスコア3とした。相対速度の3回目延長率は、3回目に暴露された液体を吸収するのに、1回目よりもどの程度余分に時間がかかったかを示している。スコア3は、3回目に暴露された液体の吸収に余分にかかる時間をどの程度抑制できたかを示しており、スコア3が1未満の場合、3回目の液体吸収時でもその抑制効果が奏されたと評価でき、スコア3が小さいほど、3回目の液体吸収時におけるその抑制効果が高いと評価できる。スコア3でも1未満を奏する積層体は、複数回の液体暴露に対する吸収速度の向上効果が格別顕著に優れていると評価できる。結果を表1に示す。
浸透速度の測定に使用した後の積層体を使用し、以下の手順で逆戻り量の測定を行った。3回目の試験液の投入から60分経過後、トップシート上の試験液投入位置付近に、あらかじめ質量(Wf[g])を測定しておいた10cm四方の濾紙を置き、その上に底面が10cm×10cmの質量5kgの重りを載せた。5分間の荷重後、濾紙の質量(We[g])を測定し、増加した質量を逆戻り量[g]とした。逆戻り量の試験は25℃、湿度50%(RH)に調節された室内で行った。逆戻り量の値が小さいほど、逆戻り抑制効果に優れているといえる。結果を表1に示す。
逆戻り量[g]=We-Wf
10’…液体を吸収した状態の積層体
20,20a,20b…透液性の第1シート
21…高濡れ性領域
22…低濡れ性領域
30,30c…第2シート
40…吸水性樹脂層
40’…水を吸収した状態の吸水性樹脂層
45…第1の吸水性樹脂層
46…第2の吸水性樹脂層
50…透液性中間層
S2…第1シートの吸水性樹脂層の側の面
LD21…(高濡れ性領域の)長手方向
SD21…高濡れ領域(及び低濡れ性領域)の短手方向
LD10…(積層体の)長手方向
LMD10…(積層体の)積層方向
Claims (11)
- 透液性の第1シートと、第2シートと、前記第1シート及び前記第2シートの間に介在する吸水性樹脂層と、を含む積層体であって、
前記第1シートの前記吸水性樹脂層の側の面が、長手方向を有する形状の高濡れ性領域と、低濡れ性領域とを含み、前記高濡れ性領域におけるホルムアミドに対する接触角が、前記低濡れ性領域におけるホルムアミドに対する接触角よりも10°以上小さい、積層体。 - 前記高濡れ性領域が凹条を成している、請求項1に記載の積層体。
- 前記高濡れ性領域と前記低濡れ性領域とが面一である、請求項1に記載の積層体。
- 前記低濡れ性領域が長手方向を有する形状であり、前記高濡れ性領域と前記低濡れ性領域とが、それらの領域の短手方向に交互に複数配置されている、請求項1~3のいずれかに記載の積層体。
- 前記高濡れ性領域と前記低濡れ性領域とが複数並列して配置されている、請求項4に記載の積層体。
- 前記積層体が長手方向を有する形状であり、
前記高濡れ性領域が、前記積層体の長手方向を含む方向に延在する、請求項1~5のいずれかに記載の積層体。 - 前記高濡れ性領域が、前記積層体の長手方向に略平行に延在する、請求項6に記載の積層体。
- 前記吸水性樹脂層が、第1の吸水性樹脂層と、透液性中間層と、第2の吸水性樹脂とをこの順で有する複層である、請求項1~7のいずれかに記載の積層体。
- 前記第1シートが樹脂繊維製である、請求項1~8のいずれかに記載の積層体。
- 前記樹脂がポリオレフィンである、請求項9に記載の積層体。
- 請求項1~10のいずれかに記載の積層体を含む、吸収性物品。
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH02102650A (ja) * | 1988-10-11 | 1990-04-16 | Honshu Paper Co Ltd | 使い捨ておむつ |
WO2008108476A1 (ja) * | 2007-03-01 | 2008-09-12 | Daiki Co., Ltd. | 吸収体及び該吸収体を使用する衛生用品並びにそれらの製造方法 |
JP2011510785A (ja) * | 2008-02-15 | 2011-04-07 | ザ プロクター アンド ギャンブル カンパニー | 吸収性物品 |
WO2020213733A1 (ja) * | 2019-04-19 | 2020-10-22 | ユニ・チャーム株式会社 | 吸収性物品 |
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JPH02102650A (ja) * | 1988-10-11 | 1990-04-16 | Honshu Paper Co Ltd | 使い捨ておむつ |
WO2008108476A1 (ja) * | 2007-03-01 | 2008-09-12 | Daiki Co., Ltd. | 吸収体及び該吸収体を使用する衛生用品並びにそれらの製造方法 |
JP2011510785A (ja) * | 2008-02-15 | 2011-04-07 | ザ プロクター アンド ギャンブル カンパニー | 吸収性物品 |
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