JP2023054545A - multilayer sheet - Google Patents

Abstract

To provide a multilayer sheet that is thin and has a desired water absorption capacity with changes in thickness before and after water absorption being small.SOLUTION: A multilayer sheet of the present invention is a multilayer sheet having a liquid-permeable layer and a water-absorbing layer, and is characterized in that the thickness of the multilayer sheet is 3 mm or less, the liquid return amount is 2.2 g or less, and the water absorption amount is 580 g/m2 to 2,000 g/m2.SELECTED DRAWING: None

Description

The present invention relates to multilayer sheets.

Floor sheets are used to prevent floors from being contaminated with washing water, blood, body fluids, and chemical fluids in washrooms, various plumbing areas, examination rooms, and surgery in medical facilities. This floor sheet is used not only to prevent the floor from becoming dirty, but also to prevent contamination of medical staff, equipment, etc., and also to prevent falls caused by water droplets scattered on the floor.

For example, Patent Literature 1 discloses a multi-layer sheet in which a long fiber nonwoven fabric layer, an absorbent short fiber nonwoven fabric layer and a waterproof layer are laminated in this order.

Japanese Patent Application Laid-Open No. 2001-232707

Floor sheets used in medical settings are required to absorb scattered liquid, prevent the liquid once absorbed from returning, and provide a dry feeling after absorption. The thickness of the floor sheet itself is also important. If the thickness of the floor sheet increases, a level difference with the floor will occur, making it difficult to pass a trolley or cart. Conventionally used floor sheets do not have sufficient water absorption performance, and there is room for improvement. SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer sheet that is thin and has a desired water-absorbing capacity and that has a small change in thickness before and after water absorption.

The multilayer sheet of the present invention is a multilayer sheet having a liquid permeable layer and a water absorbing layer, wherein the multilayer sheet has a thickness of 3 mm or less, a liquid return amount of 2.2 g or less, and a water absorption amount of 580 g/m2. ² to 2,000 g/m ² .

ADVANTAGE OF THE INVENTION According to this invention, the sheet|seat which is thin and has desired water absorption performance, and the thickness change before and after water absorption is small can be provided. In addition, the multilayer sheet of the present invention is also excellent in dry feeling after absorbing water.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows typically an example of the multilayer sheet which concerns on one Embodiment of this invention.

The multilayer sheet of the present invention is a multilayer sheet having a liquid permeable layer and a water absorbing layer, wherein the multilayer sheet has a thickness of 3 mm or less, a liquid return amount of 2.2 g or less, and a water absorption amount of 580 g/m2. ² to 2,000 g/m ² .

The multilayer sheet of the present invention is a multilayer sheet in which a liquid permeable layer and a water absorbing layer are laminated. The thickness of the multilayer sheet is 3 mm or less, preferably 2.8 mm or less, and more preferably 2.5 mm or less. If the thickness exceeds 3 mm, the difference in level with the floor becomes large when used as a floor sheet, which is not preferable. The lower limit of the thickness of the multilayer sheet of the present invention is not particularly limited, but is preferably 0.1 mm, more preferably 0.2 mm, and even more preferably 0.3 mm. In addition, when the multilayer sheet of the present invention has a waterproof layer to be described later, it is preferable that the multilayer sheet in which the liquid-permeable layer, the water-absorbing layer and the waterproof layer are laminated satisfies the thickness range described above.

The liquid-permeable layer of the multilayer sheet of the present invention will be described. The liquid permeable layer is not particularly limited as long as it is a sheet having liquid permeability.

The liquid permeation speed of the liquid permeable layer is preferably 6 seconds or less, more preferably 5 seconds or less. When the liquid permeation rate of the liquid permeable layer exceeds 6 seconds, the water absorption rate of the multilayer sheet is reduced. As a result, water droplets and the like are likely to remain on the multilayer sheet, and there is a risk of overturning.

The liquid permeable layer preferably has openings, for example. Water droplets and the like can easily pass through the liquid-permeable layer through the openings.

The shape of the opening is not particularly limited, but may include circular, elliptical, polygonal such as triangular, quadrangular, pentagonal, and hexagonal, and irregular. The openings of the liquid-permeable layer may have only one shape, or may have two or more shapes. The shape of the openings of the liquid permeable layer is preferably circular.

The size of the opening is not particularly limited, but for example, the minimum circumscribed circle diameter (diameter) of the opening is preferably 1.2 mm or less, more preferably 1.1 mm or less, and even more preferably 1.0 mm or less. . If the minimum circumscribed circle diameter of the openings is too large, the surface strength of the multilayer sheet may be lowered and the sheet may be easily damaged. Although the lower limit of the minimum circumscribed circle diameter of the opening is not particularly limited, it is preferably 0.1 mm, more preferably 0.15 mm, and still more preferably 0.2 mm. The minimum circumscribed circle diameter of the openings is preferably the number average diameter of the minimum circumscribed circle diameters of the openings per unit area (1 cm ² ).

The aperture ratio of the liquid permeable layer is preferably 20% or more, more preferably 22% or more, still more preferably 24% or more, preferably 75% or less, more preferably 65% or less, and even more preferably 55% or less. If the aperture ratio of the liquid permeable layer is within the above range, the absorption rate of the multilayer sheet will be high. The aperture ratio is the percentage of the total aperture area per unit area (1 cm ² ).

The liquid-permeable layer is preferably a liquid-permeable sheet and/or a liquid-permeable film, more preferably a liquid-permeable sheet and/or a liquid-permeable film having openings. Materials constituting the sheet and/or film are not particularly limited, but examples include polylactic acid, polyglycolic acid, hydroxycarboxylic acid-based polyesters having 1 to 6 carbon atoms such as polyhydroxybutyrate, polycaprolactone, and polyethylene. Aliphatic polyesters such as adipate and polybutylene succinate; semi-aromatic polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT); polyarylates Aromatic polyester such as; acrylic resin; vinylidene (vinyl chloride or vinylidene chloride copolymer); polyamide such as aramid, nylon, polyolefin such as polyethylene, polypropylene; polyurethane; ethylene vinyl alcohol, polyvinyl chloride, polyvinyl alcohol polyvinyl compounds; and polyparaphenylenebenzoxazole (PBO), acetate, triacetate, cellophane, and the like.

In the present invention, a polyolefin sheet and/or polyolefin film having openings is preferably used as the liquid-permeable layer, and a polyethylene sheet and/or polyethylene film having openings is more preferably used.

"Sheets" and "films" are thin, flat shapes whose thickness is generally small relative to their length and width. For example, in a narrow sense, a thickness of 100 μm or more is called a sheet, and a thickness of less than 100 μm is sometimes called a film. However, the boundary between the sheet and the film is not clear, and unless otherwise specified in the present invention, the term "sheet" includes the term "film", and the term "film" also includes the term "film". sheet".

The water-absorbing layer of the multilayer sheet of the present invention will be described.

The water absorption amount of the water absorbing layer is, for example, preferably 600 g/m ² or more, more preferably 650 g/m ² or more, further preferably 700 g/m ² or more, and 2,000 g/m 2 or more. It is preferably m ² or less, more preferably 1,900 g/m ² or less. If the water absorption amount of the water-absorbing layer is within the above range, for example, it is possible to absorb the liquid scattered on the multilayer sheet, and to prevent overturning and spread of contamination.

The water-absorbing layer preferably has a thickness that does not change before and after absorbing water. If the sheet becomes thick after absorbing water, it is not preferable because the difference in level with the floor becomes large when it is used as a floor sheet. From this point of view, for example, it is not preferable to use a water-absorbing resin having a water absorption of 25 g/g or more. Examples of the water-absorbing resin having a water absorption of 25 g/g or more include water-absorbing resins used in paper diapers, urine pads, etc. Specific examples include acrylic acid, polysaccharides containing starch, amino acids, and the like. A neutralized product of a crosslinked polymer containing as a main component can be mentioned.

The water absorbing layer is preferably a short fiber nonwoven fabric, preferably an air-laid nonwoven fabric. The air lay method is, for example, conveying short fibers containing heat-adhesive synthetic fibers while uniformly dispersing them in an air flow, and blowing out the short fibers from a screen having pores provided in the discharge part, and placing the short fibers in the lower part. In this method, a nonwoven fabric is produced by depositing the short fibers on a metal or plastic net and depositing the short fibers on the net while sucking air under the net. The thermoadhesive synthetic fibers improve the shape retention of the air-laid nonwoven fabric obtained by binding short fibers.

Thus, in the nonwoven fabric produced by the air laying method, short fibers can be randomly three-dimensionally oriented in the width direction and the thickness direction. Therefore, the air-laid nonwoven fabric has a large number of voids and an increased water absorption. In addition, the air-laid nonwoven fabric has a feature that the change in thickness is small even if it absorbs water.

The short fibers that can constitute the air-laid nonwoven fabric will now be described. The short fibers are not particularly limited, but examples thereof include synthetic fibers, regenerated fibers, semi-synthetic fibers, inorganic fibers, and natural fibers.

Examples of the synthetic fibers include hydroxycarboxylic acid-based polyesters having 1 to 6 carbon atoms such as polylactic acid, polyglycolic acid, and polyhydroxybutyrate, and aliphatic polyesters such as polycaprolactone, polyethylene adipate, and polybutylene succinate. Fiber; semi-aromatic polyester fiber such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT); aromatic polyester fiber such as polyarylate; acrylic fiber Vinylidene fiber (vinyl chloride or vinylidene chloride copolymer; polyamide fiber such as aramid and nylon; polyolefin fiber such as polyethylene and polypropylene; polyurethane fiber; fiber made of polyvinyl compound such as ethylene vinyl alcohol, polyvinyl chloride and polyvinyl alcohol; and polyparaphenylene benzoxazole (PBO) fibers.

Examples of regenerated fibers include rayon polynosic and cupra. Semi-synthetic fibers include, for example, acetate, triacetate, and Promix. Examples of inorganic fibers include glass fibers, metal fibers, and carbon fibers. Examples of natural fibers include wool, cotton, hemp, pulp, and the like.

It is also preferable to use thermoadhesive composite fibers as the short fibers. Examples of the heat-adhesive conjugate fibers include a core-sheath type in which a low melting point component is a sheath component and a high melting point component is a core component, and a side-by-side type in which one is a low melting point component and the other is a high melting point component. . Combinations of both components of these conjugate staple fibers include PP (polypropylene)/PE (polyethylene), PET (polyethylene terephthalate)/PE, PP/low melting point copolymer PP, PET/low melting point copolymer polyester, and the like. be done.

The melting point of the heat adhesive component, which is the low melting point component, is preferably 80°C to 180°C, more preferably 90°C to 160°C. When the temperature is less than 80°C, the heat resistance of the fiber is low, and troubles tend to occur in the manufacturing process. .

The short fibers preferably have a fiber length of 0.4 mm to 20 mm, more preferably 0.6 mm to 10 mm, even more preferably 1 mm to 4 mm. If the fiber length is less than 0.4 mm, the effect of increasing the strength and rigidity is not sufficient.

The basis weight of the water absorbing layer is preferably 30 g/m ² or more, more preferably 40 g/m ² or more, still more preferably 50 g/m ² or more, preferably 200 g/m ² or less, more preferably 170 g/m ² or less, and 150 g. /m ² or less is more preferable. If the basis weight of the water-absorbing layer is within the above range, the balance between handleability and water absorption is improved.

The liquid-permeable layer and water-absorbent layer of the present invention may be an integrated sheet having a density gradient. As a specific example, a multi-layered nonwoven fabric having different thicknesses and densities of fibers between layers can be mentioned.

The multilayer sheet of the present invention preferably further has a waterproof layer on the water absorbing layer side. In this preferred embodiment, the liquid permeable layer, the water absorbing layer and the waterproof layer are laminated in this order.

The waterproof layer will be described below. The waterproof layer prevents leakage of liquid absorbed by the multilayer sheet. The waterproof layer is not particularly limited as long as it has waterproof performance, and examples thereof include a waterproof sheet and/or a waterproof film. Waterproof sheets and/or films include, for example, sheets and/or films made of resin components such as polyolefins such as polyethylene and polypropylene, polyester, polyamide, polyurethane, polyvinyl alcohol, ethylene vinyl alcohol, and acetate.

The thickness of the waterproof layer is not particularly limited, but is preferably 0.01 mm or more, more preferably 0.02 mm or more, preferably 0.1 mm or less, and more preferably 0.09 mm or less. If the waterproof layer is too thin, pinholes and the like are likely to occur, which may reduce the waterproofness. Also, if the waterproof layer is too thick, the flexibility will be reduced.

A method for manufacturing the multilayer sheet of the present invention will be described. The liquid-permeable layer and water-absorbing layer of the multilayer sheet of the present invention can be fixed with, for example, a hot-melt adhesive. It is also preferable to fix the liquid-permeable layer and the water-absorbing layer by needle punching. For example, a sheet and/or film used as the liquid-permeable layer, which has no openings, is laminated on the water-absorbent layer, and then the sheet and/or film is provided with openings by needle punching, The film and water absorbing layer can be integrated.

The lamination method for forming the waterproof layer on the water-absorbing layer of the multilayer sheet of the present invention is not particularly limited, and known lamination means such as heat lamination, extrusion lamination, dry lamination, and hot-melt lamination are employed. be done.

As a method for laminating the waterproof layer, it is preferable to adopt, for example, an extrusion lamination method. First, the liquid permeable layer and the water absorbing layer are integrated in advance. The resin constituting the waterproof layer is melted and kneaded by an extruder, extruded into a film form from a T-die, and laminated on the water absorbing layer side. By this method, the waterproof layer can be laminated integrally with the preliminary laminate of the liquid permeable layer and the water absorbing layer.

It is also preferable to fix the water-absorbing layer and waterproof layer of the multilayer sheet of the present invention with, for example, a hot-melt adhesive.

The water absorption of the multilayer sheet of the present invention is, for example, preferably 580 g/m ² or more, more preferably 620 g/m ² or more, even more preferably 700 g/m ² or more, and 2000 g/m 2 or more. It is preferably m ² or less, more preferably 1900 g/m ² or less. If the water absorption amount of the multilayer sheet is within the above range, for example, the multilayer sheet can absorb the liquid splashed, thereby preventing overturning and spread of contamination.

The liquid return amount of the multilayer sheet of the present invention is preferably 2.2 g or less, more preferably 2 g or less. By reducing the amount of liquid return, it is possible to prevent overturning due to water droplets that have returned liquid. The liquid return amount is not particularly limited, but is preferably 0 g.

The multilayer sheet of the present invention preferably has a surface dryness value of 40% or more, preferably 45% or more, and more preferably 50% or more. This is because when the surface dryness value of the multilayer sheet is within the above range, the liquid does not seep out from the water-absorbed portion, making it difficult to spread contamination.

The rate of change in thickness of the multilayer sheet of the present invention before and after water absorption is preferably 10% or less, more preferably 5% or less, more preferably 3% or less, and particularly preferably 0%. This is because if the thickness after absorbing water becomes larger than the thickness before absorbing water, the difference in level becomes large, which may cause overturning.
The change rate of thickness is represented by the following formula.
Rate of change in thickness = (thickness after water absorption - thickness before water absorption) / thickness before water absorption x 100

FIG. 1 is an explanatory diagram schematically showing an example of the multilayer sheet of the present invention. The multilayer sheet 1 has a liquid permeable layer 3 , a water absorbing layer 5 and a waterproof layer 7 . The water absorbing layer 5 is located between the permeable layer 3 and the waterproof layer 7 . The liquid permeable layer 3 has openings 9 . When the multilayer sheet of the present invention is used as a floor sheet, it is used with the permeable layer 3 side facing up.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples, and any modifications and embodiments that do not depart from the scope of the present invention can be made within the scope of the present invention. Included in scope.

[Measuring method"
(1) Amount of Water Absorption A sample of 5 cm×5 cm is prepared and its mass (Ag) is measured. The sample was immersed in tap water for 1 minute, and placed so that the waterproof layer side was in contact with a plane inclined at 45 degrees. Excess water was removed by allowing to stand for 30 seconds. After that, the mass (Bg) of the sample was measured and taken as the mass after water absorption.
The amount of water absorption was calculated by the following formula.
Water absorption (g/m ² ) = (BA) x 400

(2) Thickness Measured using a thickness gauge (Daiei FS-60DS, measuring terminal φ50 mm).

(3) Liquid return property Measure the mass (Ag) of the filter paper. 5 mL of water is injected into the center of a sample of 12.5 cm x 15 cm with a dropper and allowed to stand for 5 minutes. After that, a filter paper (90φ filter paper weight: 20 g ± 1 g) is placed on the liquid injection part and allowed to stand still for 30 seconds. After the test, the mass (Bg) of the filter paper was measured, and the liquid return amount was calculated by the following formula.
Liquid return amount (g) = BA

(4) Liquid permeability test method At the lower end of the opening of a vertical cylinder (inner diameter 25.4 mm), a wire mesh (opening 150 μm, biocolumn sintered stainless steel filter 30 SUS manufactured by Sansho Co., Ltd.) and a cock ( Prepare a filtration cylindrical tube equipped with a narrow tube (inner diameter 4 mm, length 8 cm) with an inner diameter of 2 mm), set a measurement sample cut to a size of 28 mm in diameter on a wire mesh, and put it in the cylindrical tube with the cock closed. , 100 mL of water is added. Next, a cylindrical rod with a diameter of 2 mm having a wire mesh with an opening of 150 μm and a diameter of 25 mm at the tip is inserted into the cylindrical filtration tube so that the wire mesh and the measurement sample are in contact, and left in this state for 1 minute. , Open the cock to let the liquid flow, and measure the time (T1) (seconds) until the liquid level in the cylindrical tube reaches the 40 mL scale line from the 60 mL scale line (that is, 20 mL of liquid passes through). Using the measured time T1 (seconds), the liquid permeation rate is calculated from the following equation. In the formula, T0 (seconds) is a value obtained by measuring the time required for 20 ml of water to pass through the wire mesh without putting the measurement sample into the filtration cylindrical tube.

Liquid permeation rate (seconds) = (T1-T0)
The measurement was performed 5 times (n=5), the values at each of the upper and lower points were deleted, and the average value of the remaining 3 points was used as the measured value. These measurements are performed at 23±2° C. and a relative humidity of 50±5%, and the samples are stored in the same environment for 24 hours or longer before the measurements.

(5) Surface dryness value by SDME The surface dryness value by SDME was measured by the following procedure using an SDME (Surface Dryness Measurement Equipment) tester (manufactured by WK system). A 0% dryness value was set by placing the detector of the SDME tester on top of a sufficiently wet sample (soaked in enough water to cover the sample and left for 60 minutes). Next, the detector of the SDME tester was placed on the dry sample (heat dried at 50° C. for 2 hours), 100% dryness was set, and the SDME tester was calibrated.

Next, an acrylic resin ring (inner diameter: 70 mm, outer diameter: 80 mm, length: 50 mm, weight: 50 g) was set in the center of the sample to be measured, and 5 mL of 0.9% physiological saline was injected. Two minutes after the injection, the acrylic resin ring was removed, the SDME detector was set in the center of the sample so as to be in contact with the sample, and the measurement was started. The value 5 minutes after the start of measurement was taken as the surface dryness value by SDME.

(6) Monitor Evaluation Test A sample sheet of 25 cm×40 cm was pasted on the floor, and 20 cc of tap water was added from a height of 75 cm. A filter paper of the same size as the sample sheet was placed side by side with the sample pasted on the floor so that there was no gap between them. Two minutes after the liquid was added, a 5 kg four-wheeled cart passed over the sample sheet and filter paper at a speed of 0.8 m/s. let me At this time, at least two of the wheels were passed over the liquid input section. The feeling of use was monitored and evaluated by the ease of passing the cart and the wheel marks left on the filter paper.
Evaluation criteria:
○: Good △: Normal ×: Not good

[Preparation of multilayer sheet]
(Multilayer sheet 1)
A multilayer sheet was produced by laminating the liquid-permeable layer, the water-absorbing layer, and the waterproof layer in this order. Adhesion between the liquid permeable layer and the water absorbing layer and adhesion between the water absorbing layer and the waterproof layer were performed using a hot-melt adhesive. The following materials were used as the liquid-permeable layer, the water-absorbing layer, and the waterproof layer.
Liquid permeable layer: HS-52 manufactured by Berry (polyethylene sheet with an aperture ratio of 26%: liquid permeation rate of 4.00 seconds)
Water absorbing layer 1: Air-laid nonwoven fabric having a basis weight of 70 g/m ² and a thickness of 1.2 mm Waterproof layer: Tretec R213 manufactured by Toray Advanced Film Co., Ltd.

(Multilayer sheet 2)
Multilayer sheet 2 was produced in the same manner as multilayer sheet 1, except that an air-laid nonwoven fabric (water absorption layer 2) having a basis weight of 125 g/m ² and a thickness of 2 mm was used as the water absorption layer.

(Multilayer sheet 3)
A multilayer sheet 3 was produced in the same manner as the multilayer sheet 1, except that Berry's PTA (polyethylene sheet with an aperture ratio of 45%: liquid permeation rate: 2.35 seconds) was used as the liquid-permeable layer.

(Multilayer sheet 4)
A multilayer sheet 4 was produced in the same manner as the multilayer sheet 3, except that an air-laid nonwoven fabric (water absorbing layer 2) having a basis weight of 125 g/m ² and a thickness of 2 mm was used as the water absorbing layer.

(Multilayer sheet 5)
A multilayer sheet 5 was produced in the same manner as the multilayer sheet 3, except that an air-laid nonwoven fabric (water absorbing layer 3) having a basis weight of 60 g/m ² and a thickness of 1 mm was used as the water absorbing layer.

(Multilayer sheet 6)
A multilayer sheet 6 was produced in the same manner as the multilayer sheet 3 except that an air-laid nonwoven fabric (water absorbing layer 4) having a basis weight of 60 g/m ² and a thickness of 0.9 mm was used as the water absorbing layer.

(Multilayer sheet 7)
A multilayer sheet 7 was produced in the same manner as the multilayer sheet 3, except that an air-laid nonwoven fabric (water absorbing layer 5) having a basis weight of 150 g/m ² and a thickness of 2.9 mm was used as the water absorbing layer.

(Multilayer sheet 8)
A multilayer sheet 8 was produced in the same manner as the multilayer sheet 1, except that a spunlace nonwoven fabric WJ40R (liquid permeation rate: 6.05 seconds) manufactured by Kinsei Paper Co., Ltd. was used as the liquid-permeable layer.

(Multilayer sheet 9)
A multilayer sheet 9 was produced in the same manner as the multilayer sheet 2, except that a spunlace nonwoven fabric WJ40R (liquid permeation rate: 6.05 seconds) manufactured by Kinsei Paper Co., Ltd. was used as the liquid-permeable layer.

(Multilayer sheet 10)
A commercially available multilayer sheet (thickness 0.7 mm) in which a nonwoven fabric layer is laminated to a waterproof layer was evaluated.

(Multilayer sheet 11)
A commercially available multilayer sheet (thickness 0.4 mm) in which a nonwoven fabric layer is laminated to a waterproof layer was evaluated.

Table 1 shows the structure of the multilayer sheet and the evaluation results.

From the results in Table 1, the multilayer sheet has a liquid-permeable layer and a water-absorbing layer, and the multilayer sheet has a thickness of 3 mm or less, a liquid return amount of 2.2 g or less, and a water absorption amount of 580 g/m ^{2 .} It can be seen that the multilayer sheets 1 to 6, which have a weight of ∼2,000 g/m ² , have a small change in thickness before and after absorbing water while having a desired water absorption capacity.

The multi-layer sheet of the present invention can be suitably used as medical drapes, examination sheets, water-absorbing sheets for operating tables, drip sheets, floor sheets for medical sites, and the like. In addition to medical and nursing care sites, it can also be used in places and situations where antifouling and water absorption are required, such as living spaces (kitchens, bathrooms, dressing rooms, around toilets), water areas in stores, public facilities, etc. be able to. It can be suitably used as various drip sheets for food, anti-condensation sheets, pet sheets, oil-absorbing sheets for kitchens, washing water-absorbing sheets for industrial use, cutting oil-absorbing sheets, and reagent-absorbing sheets for research institutes.

Claims (9)

A multilayer sheet having a liquid-permeable layer and a water-absorbing layer,
The multilayer sheet has a thickness of 3 mm or less,
The liquid return amount is 2.2 g or less,
A multilayer sheet characterized by having a water absorption of 580 g/m ² to 2,000 g/m ² . 2. The multilayer sheet according to claim 1, further comprising a waterproof layer on the water absorbing layer side. 3. The multilayer sheet according to claim 1 or 2, wherein the water-absorbent layer contains a staple fiber nonwoven fabric. The multilayer sheet according to any one of claims 1 to 3, wherein the water-absorbent layer is an air-laid nonwoven fabric. 5. The multilayer sheet according to any one of claims 1 to 4, wherein the liquid permeable layer has a liquid permeation rate of 6 seconds or less. The multilayer sheet according to any one of claims 1 to 5, wherein the liquid-permeable layer is a sheet and/or film having openings. The multilayer sheet according to any one of claims 1 to 6, which has a surface dryness value of 40% or more. 8. The multilayer sheet according to any one of claims 1 to 7, wherein the rate of change in thickness before and after water absorption is 10% or less. The multilayer sheet according to any one of claims 1 to 8, which is a floor sheet.

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