Sheets and rolls for absorbent rolls

Abstract

To provide a liquid absorbing roll with a surface being hardly decreased in smoothness during use, which is formed by laminating annular sheets including nonwoven fabric, and a sheet for liquid absorbing roll that realizes such a liquid absorbing roll.SOLUTION: A sheet for liquid absorbing roll to be used is formed of a nonwoven fabric containing polymer elastomer including a nonwoven fabric and polymer elastomer applied on the nonwoven fabric. Area ratio of the polymer elastomer existing on a surface of the nonwoven fabric is 10% or more. When the nonwoven fabrics containing polymer elastomer are laminated and thermocompressed in a direction perpendicular to a surface of the laminated body by load of 6.0 kgf / cm2 at 130°C, peel strength is 100 g / 2.5 cm or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sheet for an absorbent roll made of a nonwoven fabric and a polymer elastic material, and to an improvement of an absorbent roll formed by stacking the absorbent roll sheet (annular sheet). [Background technology]

[0002] Conventionally, in the manufacturing process of articles, absorbent rolls are known that are formed by stacking annular sheets containing nonwoven fabric and used to remove excess liquid after processes such as cleaning the surface of a workpiece or applying a chemical to the surface.

[0003] Patent Document 1 below discloses an absorbent roll in which a fibrous sheet, in which a polymer substance is filled into a porous structure in the voids of a lotus root-shaped nonwoven mat in which porous fibers or ultrafine fiber bundles are three-dimensionally intertwined, is coated and adhered to the roller surface.

[0004] Patent Document 2 below discloses a nonwoven roll made by stacking a large number of disc-shaped objects made of synthetic fiber nonwoven fabric, characterized in that the nonwoven fabric is composed of a long fiber entanglement including hydrophilic ultrafine elongated fibers made of polyamide fiber.

[0005] Patent Document 3 below discloses an absorbent roll comprising a roll shaft and an absorbent member surrounding it, characterized in that the absorbent member is made of a nonwoven fabric consisting of ultrafine fibers that have been subjected to a water flow entanglement treatment.

[0006] Patent Document 4 below comprises a nonwoven fabric containing long fibers and a polymeric elastic material in an amount of 10-30% by mass applied to the nonwoven fabric, and in a circular cut piece with a diameter of 113 mm, the water content is 100% by mass and 2.0 kgf / cm³. 2The present invention discloses a sheet for liquid-absorbing rolls characterized in that the rate of change in diameter when compressed in the planar direction under a load is 2.0% or less. However, adjusting the area ratio of polymeric elastic material present on the nonwoven fabric surface, and thereby preventing a decrease in the smoothness of the liquid-absorbing roll surface, has not been considered. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Public Gazette No. 50-10012 [Patent Document 2] Japanese Patent Publication No. 2004-028162 [Patent Document 3] Japanese Patent Application Publication No. 8-159658 [Patent Document 4] Japanese Patent Publication No. 2019-183364 [Overview of the project] [Problems that the invention aims to solve]

[0008] Absorbent rolls, manufactured by stacking numerous annular sheets containing nonwoven fabric and compressing them tightly from both sides in the stacking direction, are used to absorb liquids adhering to the surface of a workpiece. For example, to remove excess cleaning solution remaining on the surface of a workpiece, the surface of a rotating absorbent roll is brought into contact with the surface of a moving workpiece, allowing the stacked sheets containing nonwoven fabric that form the absorbent roll to absorb the liquid. When a rotating absorbent roll is brought into contact with the surface of a workpiece, streaks or marks may remain on the surface. These streaks are caused by the absorption roll not making even contact with the surface of the workpiece due to fine irregularities on its surface. Conventionally, in such absorbent rolls, the surface of the absorbent roll was polished to make it smooth so that it made even contact with the surface of the workpiece. However, even with smoothly polished absorbent rolls, the aforementioned streaks or marks may remain over time. The inventors of the present invention have discovered that even with liquid-absorbing rolls that have a smooth surface, the reason why such streaks remain when the liquid-absorbing roll is used is that the circular sheet deforms slightly when it absorbs water, causing fine irregularities to occur on the outer surface of the liquid-absorbing roll, reducing its smoothness, and making it difficult for the outer surface of the liquid-absorbing roll to make even contact with the surface of the material to be treated.

[0009] The present invention aims to provide an absorbent roll that does not easily lose surface smoothness during use, and an absorbent roll sheet that enables such an absorbent roll. [Means for solving the problem]

[0010] One aspect of the present invention is a sheet for an absorbent roll made of a polymer-elastic nonwoven fabric comprising a nonwoven fabric and a polymer-elastic material applied to the nonwoven fabric, wherein the area ratio of the polymer-elastic material present on the surface of the polymer-elastic nonwoven fabric is 10% or more, and the polymer-elastic nonwoven fabric is laminated, and the resulting laminate can withstand 6.0 kgf / cm² at 130°C. 2 This is a sheet for liquid absorbent rolls in which the peel strength (hereinafter sometimes referred to as "thermo-pressure peel strength") when heat-pressed onto the surface of the laminate in a direction perpendicular to the load is 100 g / 2.5 cm or more. According to such a sheet for a liquid absorption roll, even when liquid is absorbed, a liquid absorption roll that is difficult to deform and whose surface smoothness is difficult to decrease during use can be manufactured.

[0011] It is preferable that the polymer elastic body-containing nonwoven fabric contains 15 to 50% by mass of the polymer elastic body, from the viewpoint that it is easy to obtain a sheet for a liquid absorption roll having the above-described thermocompression bonding peel strength.

[0012] The nonwoven fabric is composed of polyester fibers of 0.01 to 1 dtex, and the polymer elastic body is polyurethane, which is preferable from the viewpoint that the rigidity hardly decreases significantly even when water is absorbed, and the deformation of the liquid absorption roll during liquid absorption can be suppressed.

[0013] It is preferable that the fibers constituting the nonwoven fabric are long fibers, from the viewpoint that it is possible to suppress the fibers from falling off when the outer peripheral surface of the rotating liquid absorption roll is brought into contact with the workpiece.

[0014] Also, the nonwoven fabric preferably has an apparent density of 0.2 to 0.6 g / cm 3 from the viewpoint that it is easy to obtain a sheet for a liquid absorption roll having the above-described thermocompression bonding peel strength.

[0015] Another aspect of the present invention includes a stack in which a plurality of annular sheets having through holes in the center are stacked and a shaft, where the annular sheet is made of any of the above sheets for a liquid absorption roll, the shaft is inserted through the through hole of the annular sheet forming the stack, and the stack is compressed and fixed in the length direction of the shaft is a liquid absorption roll. The above liquid absorption roll hardly decreases the smoothness of the surface of the liquid absorption roll during use.

Effects of the Invention

[0016] According to the present invention, an absorbent roll formed by stacking annular sheets containing nonwoven fabric is obtained, which does not easily lose the smoothness of the absorbent roll surface during use, and an absorbent roll sheet that realizes such an absorbent roll is obtained. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a scanning electron microscope (SEM) image (magnification 50x) of the surface of the absorbent roll sheet used to measure the area ratio of the polymer elastic material (polyurethane) present on the surface of the absorbent roll sheet according to the present invention. [Figure 2] Figure 2 is an OHP sheet with the polyurethane portion of the photograph in Figure 1 blacked out and transferred onto it. [Figure 3] Figure 1 is an explanatory diagram of an absorbent roll according to one embodiment of the present invention. [Modes for carrying out the invention]

[0018] Hereinafter, one embodiment of the absorbent roll sheet and absorbent roll according to the present invention will be described in detail. The sheet for the liquid absorbent roll of this embodiment is a polymer-elastic nonwoven fabric containing a nonwoven fabric and a polymer-elastic material applied to the nonwoven fabric, wherein the area ratio of the polymer-elastic material present on the surface of the polymer-elastic nonwoven fabric is 10% or more, and the polymer-elastic nonwoven fabric is laminated, and the resulting laminate is subjected to a load of 6.0 kgf / cm² at 130°C. 2 This sheet has a peel strength of 100g / 2.5cm or more when heat-pressed onto the surface of the laminate in a direction perpendicular to the load.

[0019] First, let's explain nonwoven fabrics. The fibers that form the nonwoven fabric are not particularly limited, but examples include long fibers made of polyester such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyamides such as polyamide 6; polyolefins such as polypropylene and polyethylene; or modified versions thereof. These may be used individually or in combination of two or more. Among these, polyester fibers are preferred because they do not easily absorb water, thus preventing a decrease in rigidity during liquid absorption of the liquid absorption roll and suppressing deformation of the liquid absorption roll during liquid absorption.

[0020] While the length of the fibers is not limited, it is preferable that they be filaments or continuous fibers with a length of 30 mm or more, and even more preferably 200 mm or more. The upper limit of the fiber length is not particularly limited, but for example, it may be several meters, several hundred meters, several kilometers, or even more, when continuously spun. By using a nonwoven fabric with long fibers, it is possible to suppress the shedding of fibers when the outer surface of the rotating liquid absorption roll comes into contact with the material being treated. The fineness of the fibers is not particularly limited, but it is preferably 0.01 to 1.0 dtex, and more preferably 0.1 to 0.5 dtex. If the fineness of the fibers is too high, the contact with the material to be treated tends to decrease. Conversely, if the fineness of the fibers is too low, the fibers tend to fall off easily when the rotating liquid absorption roll comes into contact with the material to be treated.

[0021] The nonwoven fabric is preferably a three-dimensional entangled nonwoven fabric. Such a nonwoven fabric is formed, for example, by selectively removing the resin component that forms the marine component from a three-dimensional entanglement of sea-island type composite fibers, as will be described later.

[0022] In sheets for liquid-absorbing rolls, a polymeric elastic material is incorporated into the nonwoven fabric containing fibers. The type of polymeric elastic material is not particularly limited, but examples include polyurethane, polyvinyl chloride, polyamide, polyester, polyester ether copolymer, polyacrylic acid ester copolymer, neoprene, styrene-butadiene copolymer, silicone resin, polyamino acid, and polyamino acid polyurethane copolymer. These may be used individually or in combination of two or more. Among these, polyurethane is particularly preferred because it provides a flexible texture. Specific examples of polyurethane include polycarbonate-based polyurethane, polyester-based polyurethane, polyether-based polyurethane, and polycarbonate / ether-based polyurethane.

[0023] The content of the polymeric elastic material in the sheet for the liquid-absorbing roll is preferably 15 to 50% by mass, and more preferably 18 to 45% by mass. When the content of the polymeric elastic material is 15% by mass or more, when the rotating liquid-absorbing roll comes into contact with the material to be treated, the fibers are less likely to fall off and the morphological stability does not decrease, so the liquid-absorbing roll is less likely to deform. Furthermore, when the content of the polymeric elastic material is 50% by mass or less, the liquid absorption performance does not decrease and the rigidity of the liquid-absorbing roll does not decrease when absorbing water, so the durability is good.

[0024] The apparent density of the absorbent roll sheet is 0.2-0.6 g / cm³. 3 Preferably 0.28-0.46 g / cm³ 3 This is preferable because it makes it easier to obtain absorbent roll sheets with a heat-sealable peel strength of 100 g / 2.5 cm or more. The method for measuring apparent density will be described later.

[0025] The sheet for the liquid-absorbing roll has a heat-sealing peel strength of 100 g / 2.5 cm or more, preferably 150 g / 2.5 cm or more, and more preferably 200 g / 2.5 cm or more. When the heat-sealing peel strength is 100 g / 2.5 cm or more, it is possible to manufacture a liquid-absorbing roll in which the surface smoothness does not easily deteriorate even when absorbing liquid during use. On the other hand, if the heat-sealing peel strength of the sheet for the liquid-absorbing roll is less than 100 g / 2.5 cm, fine irregularities are likely to occur on the outer surface of the liquid-absorbing roll when it absorbs liquid during use. The upper limit of the above-mentioned heat-sealing release strength is not particularly limited, but a value of 500g / 2.5cm or less is sufficient to obtain the effects of the present invention. The method for measuring the heat-sealing release strength will be described later.

[0026] The thickness of the sheet for the liquid-absorbing roll is not particularly limited, but a thickness of 0.3 to 3 mm, and more preferably 0.7 to 2.5 mm, is preferable because it is easier to adjust to achieve the heat-sealing release strength described above.

[0027] Next, an example of a method for manufacturing a sheet for liquid-absorbing rolls will be described in detail. In the method for manufacturing a sheet for liquid-absorbing rolls, it is preferable to first manufacture a sea-island type composite fiber in which the resin for forming the nonwoven fabric is used as the island component, and the resin that has different chemical or physical properties from the island component and can be selectively removed is used as the sea component, and then manufacture a nonwoven fabric using this sea-island type composite fiber, as this makes it easier to adjust the fineness of the fibers forming the nonwoven fabric. Furthermore, long fibers are preferred as they can suppress fiber shedding. Next, a web of such sea-island type composite fibers is formed.

[0028] The sea-island composite fiber web is formed, for example, using the spunbond method. Specifically, a resin for forming the island component and a resin for forming the selectively removable sea component are melt-spun, the resulting molten sea-island composite fiber is cooled in a cooling device, and then stretched and thinned by a high-speed airflow at a speed corresponding to, for example, a draw speed of 1000 to 6000 m / min using a suction device such as an air jet nozzle, thereby obtaining the sea-island composite fiber. Then, by spreading the sea-island composite fiber and depositing it on a collection surface such as a mobile net, a web of long sea-island composite fibers is obtained.

[0029] Sea-island type composite fibers are long fibers in which a resin for forming island components and a resin for forming marine components that have chemical or physical properties different from the resin for forming island components and can be selectively removed form a sea-island-like cross-section. By selectively removing the marine component resin from such sea-island type composite fibers, long fibers of the resin for forming island components are formed.

[0030] The resin used to form the sea component can be any resin that differs from the resin used to form the island component in its solubility in solvents or its decomposition properties in decomposing agents, has low compatibility with the resin used to form the island component, and is melt-spinnable, without any particular limitations. Specific examples of such resins include polyethylene, ethylene propylene copolymer, ethylene vinyl acetate copolymer, styrene-ethylene copolymer, styrene-acrylic copolymer, polystyrene, and water-soluble thermoplastic polyvinyl alcohol-based resins.

[0031] As described above, after the strands of the melt-state sea-island composite fibers formed by melt composite spinning are cooled by a cooling device, they are drawn by a high-speed air flow at a speed corresponding to a take-up speed of 1000 to 6000 m / min using a suction device such as an air jet nozzle so as to obtain a target fineness. Note that as the spinning speed is higher, the crystal orientation of the fibers becomes higher, so there is a tendency for the 10% tensile strength to increase. Then, a web of long fibers is formed by depositing the drawn sea-island composite fibers on a movable collection surface. At this time, if necessary, it may be partially thermocompressed to impart form stability to the web.

[0032] Next, the webs obtained as described above are stacked in multiple layers to form a three-dimensional complex of long-fiber sea-island composite fibers. This step is a step of obtaining a three-dimensional complex in which long fibers are complexed in the thickness direction by performing a complexing treatment such as needle punching or water jet entanglement treatment after stacking the webs in multiple layers. The number of web layers to be stacked is not particularly limited, but for example, it is preferably 4 layers or more, and further preferably 8 layers or more.

[0033] A three-dimensional complex is formed by subjecting the laminate obtained by stacking multiple layers of long-fiber webs to a complexing treatment. In the case of needle punching, the type of felt needle used is not particularly limited. In order to sufficiently enhance the entanglement of the fibers in the thickness direction, it is preferable to use a thin felt needle or a felt needle with few barbs such as a 1-barbed needle. Also, from the point of suppressing the cutting of the sea-island composite fibers, it is preferable to use felt needles with 3 barbs, 6 barbs, 9 barbs, etc. Also, the number of felt needles per unit area (punching density) used in needle punching is not particularly limited, but it is preferably in the range of 200 to 2500 needles / cm 2 with respect to the surface area of the web. The basis weight of the three-dimensional complex of the sea-island composite fibers is preferably in the range of 100 to 3000 g / m 2 and further preferably in the range of 200 to 1000 g / m 2 .

[0034] Next, a solution or emulsion of a polymer elastomer is impregnated into the three-dimensional entanglement of sea-island type composite fibers, and then the polymer elastomer is solidified. The method of impregnating the three-dimensional entanglement of sea-island type composite fibers with the solution or emulsion of a polymer elastomer is not particularly limited, but for example, a method of impregnation by dipping and nipping the three-dimensional entanglement with the solution or emulsion of a polymer elastomer is preferably used. After impregnating the three-dimensional entanglement of sea-island type composite fibers with the solution or emulsion of a polymer elastomer, the polymer elastomer is solidified in the voids between the fibers of the three-dimensional entanglement of sea-island type composite fibers by wet solidification or drying to remove the water in the emulsion. In this way, the polymer elastomer is impregnated into the voids between the fibers of the three-dimensional entanglement, and a polymer elastomer-containing entanglement can be obtained.

[0035] The polymer elastomer content of the final polymer elastomer-containing nonwoven fabric is preferably 15 to 50% by mass. Within this range, the polymer elastomer is appropriately distributed on the surface of the polymer elastomer-containing nonwoven fabric, and the above-mentioned thermocompression peel strength can be obtained. Arbitrary conditions such as the specific gravity of the three-dimensional entanglement, the concentration of the polymer elastomer solution, and the impregnation ratio are adjusted so that the polymer elastomer content is 15 to 50% by mass.

[0036] When impregnating a three-dimensional entanglement of sea-island composite fibers with a polymer elastomer solution or emulsion, it is necessary to selectively control the proportion of the polymer elastomer solution or emulsion on the surface of the three-dimensional entanglement of sea-island composite fibers so that the area ratio of the polymer elastomer present on the surface of the final polymer elastomer-containing nonwoven fabric is 10% or more (including 100%). Common methods for selective control include applying contact pressure to the surface using methods such as nip rolls, squeeze bars, or doctor knives. Alternatively, this can be achieved by post-treatment of the manufactured sheet-like material. Common post-treatment methods include coating with polyurethane resin, such as gravure coater, knife coater, pipe coater, and comma coater.

[0037] Then, by wet solidification or drying to remove water from the emulsion, the polymeric elastic material solidifies in the voids between the fibers of the three-dimensional entanglement of sea-island type composite fibers. In this way, the polymeric elastic material can be imparted to the voids between the fibers of the three-dimensional entanglement.

[0038] By treating a three-dimensional entanglement of sea-island type composite fibers to which a polymeric elastic material has been added in a solvent that selectively dissolves the sea component, the resin of the sea component is dissolved and removed from the sea-island type composite fiber, forming a nonwoven fabric containing long fibers made of island component resin. As a method for dissolving and removing the resin of the sea component, for example, when the sea component is polyethylene, a method can be used in which toluene at 50 to 100°C is used, along with dyeing machines such as liquid flow dyeers and jiggers, or scouring machines such as open soapers.

[0039] After removing the marine resin components contained in the sea-island composite fiber, the raw material for the liquid-absorbing roll sheet is obtained by drying. In the manufacture of the liquid-absorbing roll sheet, it is preferable to stabilize the shape of the liquid-absorbing roll sheet by subjecting the raw material to stretching treatments such as widening treatment before and after drying. Such stretching treatment sets the nonwoven fabric containing long fibers into a shape that is less prone to stretching and shrinking by being stretched in the planar direction.

[0040] The sheet for the liquid-absorbing roll obtained in this way is cut into an annular shape and used for manufacturing the roll body of the liquid-absorbing roll. The outer diameter of the annular shape is preferably 50 to 300 mm, and more preferably 75 to 250 mm. The inner diameter of the annular shape is selected according to the diameter of the shaft, which will be described later, and is preferably 15 to 250 mm, and more preferably 25 to 200 mm.

[0041] Figure 3 is an explanatory diagram illustrating a liquid-absorbing roll 20, which includes a roll body 10 formed by stacking and compressing a large number of annularly shaped liquid-absorbing roll sheets 10a. 1 is a shaft, 2 is a fixing ring, and 3 is a workpiece conveyed in the direction of the white arrow. The shaft 1 preferably has a hollow section 1a and a through hole (not shown) formed in the part that supports the roll body 10. With such a shaft, a vacuum pump can be connected to the hollow section 1a to suck out liquid that has permeated the roll body 10, or a high-pressure pump can be connected to the hollow section 1a to discharge liquid that has permeated the roll body 10 from the liquid-absorbing roll by sending high-pressure gas to the hollow section 1a.

[0042] As shown in Figure 3, the liquid-absorbing roll 20 is formed by inserting a shaft 1 through the through-hole of an annular liquid-absorbing roll sheet 10a, which has a through-hole in the center, stacking multiple sheets, and then fixing them in a compressed state with a fixing ring 2. Such a liquid-absorbing roll 20 is manufactured, for example, as follows.

[0043] The liquid-absorbing roll sheet 10a is formed into an annular sheet, and a through hole is made to pass through the shaft 1. Multiple annular sheets of liquid-absorbing roll sheet 10a are then stacked on the outer circumference of the shaft 1. The stacked multiple sheets of liquid-absorbing roll sheet 10a are then pressed from the longitudinal direction of the shaft 1 with a press machine at a rate of 2-20 kgf / cm². 2 After compression, the compressed and stacked liquid-absorbing roll sheets 10a are fixed with fixing rings 2. Then, by leaving them for a predetermined time, the internal stress of the stacked liquid-absorbing roll sheets 10a is made uniform. Next, the surface of the stacked liquid-absorbing roll sheets 10a is smoothed by cutting and polishing with a cutting tool, knife, etc., and further, fine irregularities are removed with abrasive paper such as sandpaper or emery paper to finish the surface to a smooth surface.

[0044] The surface hardness of the roll body 10 of the liquid-absorbing roll 20 is preferably around Hs50-70, as measured by a Shore hardness test. If the hardness is too low, the wear resistance of the roll body tends to decrease. Also, if the hardness is too low, the liquid absorption tends to decrease.

[0045] As shown in Figure 3, such a liquid-absorbing roll 20 is rotated in the direction of the arrow, with the shaft 1 as the axis of rotation, while supporting both ends of the shaft 1 with a rotating mechanism (not shown), and simultaneously comes into contact with the surface of the workpiece 3 being conveyed. The contact pressure is adjusted according to the hardness of the roll surface and the material of the workpiece. Such a roll is preferably used, for example, as a liquid-absorbing roll to remove excess liquid adhering to the surface of an article or part. [Examples]

[0046] The present invention will be described in more detail below with reference to the examples. However, the scope of the present invention is not limited in any way to the examples.

[0047] First, the evaluation method used in this embodiment is summarized below.

[0048] <Fineness> A cross-section of the sheet used for the liquid-absorbing roll was imaged at 3000x magnification using a scanning electron microscope (SEM). Fifteen cross-sections of ultrafine fibers observed in the obtained images were randomly selected, and their cross-sectional areas were measured. The average of these cross-sectional areas was calculated, and the fineness was calculated from the density of each resin.

[0049] <Percentage of polymeric elastic material (polyurethane) content> The mass (W1) of approximately 10 g of a fragment of a sheet used for liquid absorbent rolls was measured. The obtained fragment was immersed in dimethylformamide for a certain period of time, and then the polymeric elastic material (polyurethane) was extracted by repeatedly performing a pressing process. The nonwoven fabric residue after extraction was dried, and the mass (W2) of the dried nonwoven fabric was measured. The polymeric elastic material content (mass %) was calculated using the following formula. Polymer elasticity content (B) = (W1 - W2) / W1 × 100 (mass%)

[0050] <Area ratio of polymeric elastic material (polyurethane) present on the sheet surface> Three average images of the surface of the absorbent roll sheet were taken using a scanning electron microscope (SEM) at 50x magnification (Figure 1), and each image was printed on A4 size paper. The printed paper was placed on an overhead projector (OHP) sheet, and the black-painted polyurethane areas were transferred to the OHP sheet (Figure 2). Then, the pattern of the OHP sheet with the black-painted polyurethane areas was captured with a scanner to form an image. Using an image processing device (image-pro plus, manufactured by Media Cybernetics), the total area of ​​the region where polyurethane is present in the obtained image was blacked out was calculated. The area ratio of polyurethane was calculated using the following formula, based on the total area of ​​the blacked-out portions in the entire region where polyurethane is present and the total area of ​​the entire image. Polyurethane area ratio (%) = Total area of ​​polyurethane in the black-painted area / Total area of ​​the entire image × 100

[0051] [Example 1] A molten sea-island composite fiber with 12 islands, containing polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, with a mass ratio of island component / sea component of 65 / 35, was extruded from a 280°C molten composite spinning die. The molten sea-island composite fiber extruded from the die was stretched and thinned while being cooled by adjusting the airflow to 4000 m / min using an air jet suction device installed directly below the die, thereby spinning a sea-island composite fiber with an average fineness of 3 dtex. The sea-island composite fiber was continuously collected on a movable net installed directly below the air jet suction device and pressed using a metal roll with a surface temperature of 70°C to obtain a basis weight of 40 g / m². 2 A web of long-fiber sea-island type composite fibers was obtained.

[0052] The resulting webs were stacked using a cross-wrapper to achieve a basis weight equivalent to 12 webs. A needle-break prevention oil was then uniformly applied to the web surface using a spray. Next, the total number of needles pierced alternately into both sides of the web was set to 2000 needles / cm². 2 By performing needle punching to entangle the long fibers of the web, the basis weight reaches 750g / m 2 We obtained a three-dimensional entangled structure.

[0053] Next, a DMF solution of polyurethane (polycarbonate-based polyurethane) was impregnated into the three-dimensional entangled body as a polymeric elastic material. By applying contact pressure to the surface of the three-dimensional entangled body and controlling the proportion of the polymeric elastic material solution on the surface, the surface area ratio of the polymeric elastic material when used as a sheet for absorbent rolls was adjusted to 23.4%. Subsequently, wet solidification was performed in a solidification bath containing an aqueous DMF solution.

[0054] A three-dimensional entanglement coated with polyurethane was dipped and nipped in hot toluene at 90°C to dissolve and remove the polyethylene from the sea-island composite fibers within the three-dimensional entanglement, thereby converting the sea-island composite fibers into PET fibers. Subsequently, it was dried in a drying oven with hot air at 100°C for 30 minutes. During this process, the polyurethane-coated three-dimensional entanglement was transported in the drying oven while widening both sides with tenter clips to produce a sheet for liquid-absorbing rolls.

[0055] The resulting absorbent roll sheet consists of a nonwoven fabric made of long PET fibers with a fineness of 0.2 dtex, and 18% by mass of polyurethane applied to the nonwoven fabric, with a thickness of 2.00 mm and a basis weight of 800 g / m². 2 That was the case.

[0056] The following evaluation was performed using the absorbent roll sheet obtained in this manner.

[0057] (Apparent density of absorbent roll sheets) Mass per unit area (g / cm²) of absorbent roll sheet 2The apparent density (g / cm³) is calculated by dividing the apparent density by its thickness (cm). 3 The results are the arithmetic mean of the apparent density measured at 10 arbitrary locations. The thickness was set to 240 gf / cm² in accordance with JIS L 1096:2010 Method A. 2 The measurement was taken under the load.

[0058] <Heat-sealed, highly removable> Two test pieces measuring 1.85 mm × 2.5 cm × 16 cm, cut from the resulting absorbent roll sheet, were subjected to a 130°C hot press with a load of 6.0 kgf / cm². 2 The materials were heat-pressed for 1 minute, and a stress-strain curve of the peel strength at the heat-pressure interface was obtained using an autograph. The stress at the time of peeling was read from the stress-strain curve, and the heat-pressure peel strength was determined. In the test, three measurements were taken in both the longitudinal and transverse directions of the original roll, and the lower of the two average values ​​was used as the heat-pressure peel strength.

[0059] (Rolling test) Numerous sheets were manufactured from the obtained absorbent roll sheet, each cut into an annular shape with a through-hole in the center. The outer diameter of the annular sheet was 50 mm, and the inner diameter (diameter of the through-hole) was 30 mm. A stack of numerous annular sheets is formed by stacking them perpendicular to the surface, a shaft is inserted through the through-holes in the annular sheets forming the stack, and a load of 5.0 kgf / cm² is applied to the stack in the direction of the shaft. 2 The absorbent roll was created by compressing and fixing it. Then, the absorbent rolls were mounted on a device having a pair of roll mounting sections (the upper absorbent roll 20 and the lower feed roll (not shown) shown in Figure 3) so that the linear pressure (contact pressure: pressure applied to the workpiece per 1 cm in the roll width direction) was 6 kgf / cm. The device was run for 24 hours at a contact pressure of 6 kgf / cm while water was supplied to the surface of the workpiece (iron plate). The outer surface of the absorbent rolls removed from the device was visually inspected, and it was determined that A was the case when no irregularities could be confirmed, and B was the case when irregularities were clearly confirmed.

[0060] [Example 2] In the manufacturing of the absorbent roll sheet of Example 1, the contact pressure was adjusted to selectively remove the polyurethane solution present on the surface of the three-dimensional entanglement, and the area ratio of the polymeric elastic material present on the surface of the final absorbent roll sheet was set to 15.3%, except that the absorbent roll sheet was manufactured in the same manner as in Example 1. The absorbent roll sheet was evaluated in the same manner as in Example 1, except that the absorbent roll sheet manufactured as described above was used instead of the absorbent roll sheet of Example 1. The results are shown in Table 1.

[0061] [Example 3] In the production of the absorbent roll sheet in Example 2, the absorbent roll sheet was manufactured in the same manner as in Example 2, except that the polymer elastomer content of the final absorbent roll sheet (polymer elastomer-containing nonwoven fabric) was adjusted to 32% by mass, and the area ratio of the polymer elastomer present on the surface of the absorbent roll sheet was adjusted to 14.2%. The absorbent roll sheet was evaluated in the same manner as in Example 1, except that the absorbent roll sheet manufactured as described above was used instead of the absorbent roll sheet of Example 1. The results are shown in Table 1.

[0062] [Example 4] In the production of the absorbent roll sheet of Example 1, the long sea-island type fibers were replaced with short fibers made of polyethylene terephthalate (length: 51 mm; fineness: 2.8 dtex), and the polymer elastomer content of the final absorbent roll sheet (polymer elastomer-containing nonwoven fabric) was adjusted to 40% by mass, and the area ratio of the polymer elastomer present on the surface of the absorbent roll sheet was adjusted to 22.8%, except that the absorbent roll sheet was manufactured in the same manner as in Example 1. The absorbent roll sheet was evaluated in the same manner as in Example 1, except that the absorbent roll sheet manufactured as described above was used instead of the absorbent roll sheet of Example 1. The results are shown in Table 1.

[0063] [Example 5] In the manufacturing of the absorbent roll sheet for Example 2, the absorbent roll sheet was manufactured in the same manner as in Example 2, except that the long sea-island type fibers were replaced with short fibers made of polyethylene terephthalate (length: 51 mm; fineness: 4.0 dtex). The absorbent roll sheet was evaluated in the same manner as in Example 1, except that the absorbent roll sheet manufactured as described above was used instead of the absorbent roll sheet for Example 1. The results are shown in Table 1.

[0064] [Comparative Example 1] In the manufacturing of the absorbent roll sheet of Example 1, the contact pressure was adjusted to selectively remove the polyurethane solution present on the surface of the three-dimensional entanglement, and the area ratio of the polymeric elastic material present on the surface of the final absorbent roll sheet was set to 6.3%, except that the absorbent roll sheet was manufactured in the same manner as in Example 1. The absorbent roll sheet was evaluated in the same manner as in Example 1, except that the absorbent roll sheet manufactured as described above was used instead of the absorbent roll sheet of Example 1. The results are shown in Table 1.

[0065] [Comparative Example 2] In the manufacturing of the liquid-absorbing roll sheet in Example 3, the contact pressure was adjusted to selectively remove the polyurethane solution present on the surface of the three-dimensional entanglement, and the area ratio of the polymeric elastic material present on the surface of the final liquid-absorbing roll sheet was set to 7.3%. Otherwise, the liquid-absorbing roll sheet was manufactured in the same manner as in Example 3. The evaluation was performed in the same manner as in Example 1, except that the liquid-absorbing roll sheet manufactured as described above was used instead of the liquid-absorbing roll sheet of Example 1. The results are shown in Table 1.

[0066] [Table 1]

[0067] From the results in Table 1, the area ratio of polymeric elastic material present on the nonwoven fabric surface (surface of the liquid absorbent roll sheet) was 10.0% or more. A 2.5 cm × 16 cm test specimen was subjected to a 130°C hot press with a load of 6.0 kgf / cm². 2In the roll running tests, no irregularities were observed on the outer surface of the absorbent rolls manufactured using the absorbent roll sheets obtained in Examples 1 to 4, which had a heat-sealing peel strength of 100 g / 2.5 cm or more after heat-sealing for 1 minute. On the other hand, in Comparative Examples 1 and 2, where the area ratio of polymeric elastic material present on the nonwoven fabric surface (surface of the sheet for the liquid-absorbing roll) was less than 10.0% and the heat-sealing peel strength was less than 100 g / 2.5 cm, the liquid-absorbing rolls manufactured using the sheets for the liquid-absorbing rolls obtained in those examples all showed clearly visible irregularities on the outer surface of the liquid-absorbing rolls during roll running tests. [Explanation of Symbols]

[0068] 1 shaft 1a Hollow part 2 Retaining rings 3. Member to be processed 10,10a Sheet for liquid absorbent roll 20 absorbent rolls

Claims

1. It consists of a nonwoven fabric and a polymer elastic material applied to the nonwoven fabric, The surface area ratio of the polymeric elastic material present on the surface of the polymeric elastic material-containing nonwoven fabric is 10% or more. The polymeric elastic material-containing nonwoven fabric is laminated, and the resulting laminate is subjected to a temperature of 6.0 kgf / cm² at 130°C. ２ The peel strength when the laminate is heat-pressed in a direction perpendicular to the surface of the laminate under a load is 100 g / 2.5 cm or more. Sheets for liquid absorbent rolls.

2. The sheet for liquid absorbent rolls according to claim 1, wherein the polymeric elastic material-containing nonwoven fabric contains 15 to 50% by mass of the polymeric elastic material.

3. The sheet for an absorbent roll according to claim 1 or 2, wherein the nonwoven fabric is composed of polyester fibers with a density of 0.01 to 1.0 dtex, and the polymeric elastic material is polyurethane.

4. The absorbent roll sheet according to claim 1 or 2, wherein the fibers forming the nonwoven fabric are long fibers.

5. 0.2~0.6g / cm 3 A sheet for an absorbent roll according to claim 1 or 2, having an apparent density.

6. A method for manufacturing a liquid absorbent roll sheet according to claim 1 or 2, The process includes controlling the area ratio of the polymeric elastic material present on the surface of the polymeric elastic material-containing nonwoven fabric to be 10% or more. The control process described above is: (a) A step of applying contact pressure to the surface of a three-dimensional entanglement of sea-island type composite fibers impregnated with a polymer elastic solution or emulsion, or (b) A step of applying a polymeric elastic solution or emulsion to the surface of the manufactured sheet-like material. A method for manufacturing a sheet for an absorbent roll, including the method described above.

7. It comprises a stacked body made of multiple annular sheets with a through hole in the center, and a shaft, The annular sheet is made from the liquid-absorbing roll sheet described in claim 1 or 2. A shaft is inserted through the through hole of the annular sheet that forms the stacked body. The aforementioned stacked body is compressed and fixed in the longitudinal direction of the shaft. Absorbent roll.

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