JP2012183175A - Water absorbent sheet configuration body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water absorbent sheet configuration body which prevents odor to be continuously generated from a body fluid and has excellent deodorization ability, while securing at a high level, basic performance (a quick liquid permeable speed, a small amount of adverse permeation, and a small amount of liquid leakage) as the water absorbent sheet configuration body even when the water absorbent sheet configuration body contains an extremely small amount of pulp.SOLUTION: The water absorbent sheet configuration body 10 includes a structure where an absorbent layer including water absorbent resins, an adsorption agent, and an adhesive is held by nonwoven cloths from above and below the absorbent layer. The water absorbent sheet configuration body has a structure where the absorbent layer is divided into a primary liquid absorbent layer 13 (1), a secondary liquid absorbent layer 15 (2), and an adsorption layer 17 containing the adsorption agent 16 (3), the adsorption layer 17 is present between the secondary liquid absorbent layer 15 and the nonwoven cloth 18 or 19, the normal saline solution absorption speed of the water absorbent resin to be used for the primary liquid absorbent layer 13 is 25-80 seconds (1), and the normal saline solution absorption speed of the water absorbent resin to be used for the secondary liquid absorbent layer 15 is 1-15 seconds (2).

Description

  The present invention relates to a water absorbent sheet structure that can be used in the field of sanitary materials and the like. Specifically, the present invention relates to a water-absorbent sheet structure that is excellent in deodorizing performance, is thin, and can be suitably used for absorbent articles such as paper diapers. Furthermore, this invention relates to absorbent articles, such as a paper diaper which uses this water absorbing sheet structure.

  Absorbent articles typified by paper diapers have an absorbent body that absorbs liquids such as body fluids on a flexible liquid-permeable surface sheet (top sheet) disposed on the side in contact with the body and on the opposite side in contact with the body. It has a structure sandwiched between a liquid-impermeable back sheet (back sheet) disposed.

  In the absorbent article, there is a problem that an unpleasant odor is generated when a body fluid, particularly urine, blood, sweat, or the like is absorbed. These odors are rotting odors that are produced when bacteria present in the skin and digestive tract produce enzymes that break down components of body fluids such as urea and proteins, and the components of body fluids are decomposed by the enzymes. It is believed that there is.

  In order to suppress the generation of these odors, an adsorbent is used for the absorber for the purpose of adsorbing and removing odor components. For the adsorbent, a physical adsorbent that removes odor by adsorbing the adsorbent surface and gas molecules of the odor component in the air by van der Waals force, and adsorbing and decomposing the odor component by chemical reaction. There are chemical adsorbents that remove odors, and physical adsorbents are preferably used because of problems such as versatility against odors, ease of use, and cost.

  As a method of using a physical adsorbent for the absorber, an absorber in which a physical adsorbent such as activated carbon is mixed with a water absorbent resin (for example, refer to Patent Documents 1 and 2), or physical adsorption on the surface of the absorber. A method for forming an adsorbing layer containing an adsorbent (see, for example, Patent Document 3), a method for forming an adsorbing layer containing a physical adsorbent in the central portion of the absorber (see, for example, Patent Document 4), and the like have been proposed.

  Conventionally, demands for thinner and lighter absorbent articles have been increased from the viewpoints of design, convenience in carrying, efficiency in distribution, and the like. Furthermore, in recent years, from the viewpoint of environmental conservation, there is a growing need for a so-called eco-friendly orientation that effectively uses resources and avoids the use of natural materials that require a long period of growth, such as trees.

  Therefore, water absorption as a water-absorbent sheet component that has very low pulverized pulp fibers such as wood, has excellent basic performance (fast liquid penetration rate, low liquid reversal amount, low liquid leakage, etc.), and achieves thinning. A water-absorbing sheet composition having a structure in which an absorbent layer containing an adhesive resin and an adhesive is sandwiched between two or more hydrophilic nonwoven fabrics (see, for example, Patent Document 5) has been proposed.

JP 07-329225 A JP 2001-037805 A JP 2001-145648 A JP 2000-051266 A International Publication WO2010 / 082373 Pamphlet

  However, in the methods disclosed in Patent Documents 1 to 4, the adsorbent comes into contact with body fluids such as urine and blood, and the deodorization performance is reduced by adsorbing moisture and proteins in the body fluid. Deodorizing effect against rot odor which decomposes and increases over time is not sufficient. Moreover, although the water absorbent sheet structure disclosed in Patent Document 5 is sufficiently excellent in the basic performance, it does not take into account the odor that is continuously generated.

  Therefore, the present invention ensures the basic performance (fast liquid permeation rate, small reversal amount, small liquid leakage amount) as a water absorbent sheet structure at a high level even with a water absorbent sheet structure with very little pulp. It is another object of the present invention to provide a water-absorbent sheet structure that prevents odors continuously generated from body fluids and has excellent deodorizing ability.

That is, the gist of the present invention is as follows.
[1] A water-absorbent sheet structure having a structure in which an absorbent layer containing a water-absorbent resin, an adsorbent and an adhesive is sandwiched from above and below the absorbent layer by a nonwoven fabric,
The absorption layer has a structure divided into 1) a primary liquid absorption layer, 2) a secondary liquid absorption layer, and 3) an adsorption layer containing an adsorbent, wherein the adsorption layer includes a secondary liquid absorption layer and Having a structure that exists between the nonwovens,
(1) The physiological saline water absorption speed of the water absorbent resin used in the primary liquid absorbent layer is 25 to 80 seconds, and (2) The physiological saline water absorption speed of the water absorbent resin used in the secondary liquid absorbent layer is 1-15 seconds,
A water-absorbing sheet structure; and [2] an absorbent article formed by sandwiching the water-absorbing sheet structure according to [1] between a liquid-permeable sheet and a liquid-impermeable sheet.

  Even if the water absorbent sheet structure according to the present invention is a water absorbent sheet structure with very little pulp, it ensures the basic performance as a water absorbent sheet structure at a high level, while continuously generating odors from body fluids. It has an excellent effect that it can prevent and deodorize sufficiently. Therefore, by using the water absorbent sheet structure according to the present invention as an absorbent body such as a disposable diaper, it is possible to provide a sanitary material that is thin and excellent in design of appearance and free from inconveniences such as liquid leakage and odor.

FIG. 1 is an enlarged cross-sectional view schematically showing the structure of a water absorbent sheet structure according to the present invention. FIG. 2 is an enlarged cross-sectional view schematically showing another structure of the water absorbent sheet structure according to the present invention. FIG. 3 is a schematic diagram of an apparatus used to perform a leak test on a slope.

  The water absorbent sheet structure according to the present invention is a water absorbent sheet structure having a structure in which an absorbent layer containing a water absorbent resin, an adsorbent and an adhesive is sandwiched from above and below the absorbent layer by a nonwoven fabric. The absorbent layer is divided into 1) a primary liquid absorption layer, 2) a secondary liquid absorption layer, and 3) an adsorption layer containing an adsorbent, and is used for the primary liquid absorption layer. The water-absorbent sheet structure is characterized in that the water-absorbent resin used in the water-absorbent resin and the secondary liquid-absorbing layer has a specific water-absorbing property, and an adsorbing layer is provided at a specific location.

  As a kind of water-absorbing resin in the water-absorbent sheet structure according to the present invention, a commercially available water-absorbing resin can be used, for example, starch-acrylonitrile graft copolymer hydrolyzate, starch-acrylic acid graft polymer neutralized Water-absorbent resins such as saponified products of vinyl acetate-acrylic acid ester copolymers, crosslinked products of partially neutralized acrylic acid polymers, and partially neutralized polyacrylic acid polymers. Among these, a cross-linked product of a partially neutralized acrylic acid polymer is preferable from an industrial viewpoint such as supply capacity and cost. For example, as a method for synthesizing a crosslinked product of a partially neutralized acrylic acid polymer, a reverse phase suspension polymerization method, an aqueous solution polymerization method, and the like can be given. Among these polymerization methods, the water-absorbent resin obtained by the reversed-phase suspension polymerization method from the viewpoint of good fluidity of particles obtained, few fine powders, and high water absorption performance such as absorption capacity and water absorption speed. Are more preferably used.

  The degree of neutralization of the crosslinked acrylic acid partial neutralized polymer is preferably 50 mol% or more, more preferably 70 to 90 mol%, from the viewpoint of increasing the osmotic pressure of the water absorbent resin and enhancing the water absorption performance.

The content of the water-absorbent resin in the water-absorbent sheet structure according to the present invention (which combines the primary liquid-absorbing layer and the secondary liquid-absorbing layer) is sufficient when the water-absorbent sheet structure is used in an absorbent article. a view of obtaining a liquid absorption performance, preferably per square meter of the water-absorbent sheet structure is 100 to 1000 g (i.e. 100 to 1000 g / m ^2), more preferably 140~800g / m ^2, more preferably 180~700g / m ^2, even more preferably from 200 to 600 g / m ^2. The content is preferably 100 g / m ² or more from the viewpoint of exhibiting sufficient liquid-absorbing performance as a water-absorbent sheet structure and suppressing reversion of the liquid, and suppresses the occurrence of gel blocking phenomenon of the water-absorbent resin. And from a viewpoint of exhibiting the spreading | diffusion performance of a liquid as a water absorbing sheet structure, and also improving the penetration rate of a liquid, it is preferable that the said content is 1000 g / m < ² > or less.

  The resin ratio (mass ratio) of the primary liquid absorption layer / secondary liquid absorption layer is preferably in the range of primary liquid absorption layer / secondary liquid absorption layer = 98/2 to 50/50. / Secondary liquid absorption layer = 90 / 10-60 / 40 is more preferable. From the viewpoint of sufficiently exhibiting the absorbability of the secondary liquid absorption layer, preventing liquid leakage in the water absorbent sheet structure, and preventing transfer of body fluid to the adsorption layer, the primary liquid absorption layer / secondary liquid absorption layer is The ratio is preferably 98/2 or less, and from the viewpoint of increasing the dry feeling of the primary liquid-absorbing layer after liquid absorption and reducing reversal in the water-absorbent sheet structure, the primary liquid-absorbing layer / secondary liquid-absorbing layer Is preferably a ratio of 50/50 or more.

  In this specification, the water absorption rate of the water absorbent resin is evaluated as the physiological saline water absorption rate. The physiological saline water absorption rate of the water absorbent resin used in the primary liquid absorption layer increases the penetration rate of the water absorbent sheet structure according to the present invention, avoids the retention of liquid in the primary liquid absorption layer, and absorbs articles. From the viewpoint of increasing the dry feeling on the skin when used in the skin, it is 25 to 80 seconds, more preferably 30 to 75 seconds, and further preferably 35 to 70 seconds. On the other hand, the physiological saline water absorption speed of the water absorbent resin used in the secondary liquid absorbent layer reduces leakage at the inclination of the water absorbent sheet structure according to the present invention, and is not caused by liquid leakage when used in absorbent articles. From the viewpoint of preventing pleasure and from the viewpoint of preventing transfer of body fluid to the adsorption layer, it is 1 to 15 seconds, and more preferably 2 to 10 seconds.

  The median particle size of the water-absorbent resin prevents the dissipation of the water-absorbent resin in the water-absorbent sheet structure and the gel blocking phenomenon at the time of water absorption regardless of whether the liquid absorbing layer is primary or secondary. From the viewpoint of improving the tactile sensation by reducing the jerky feel of the water absorbent sheet structure, 100 to 600 μm is preferable, 150 to 550 μm is more preferable, and 200 to 500 μm is even more preferable.

  In the water absorbent sheet structure according to the present invention, the adsorption layer is a layer comprising at least an adsorbent. As the adsorbent used in the adsorption layer, it is preferable to use a physical adsorbent. In the case of a chemical adsorbent that removes odors by adsorbing and decomposing odor components by chemical reaction, although the performance of odor removal and continuity is good, the reacting odor components are identified and removed for multiple odor components Therefore, it is less effective against the odor of body fluids such as urine and blood. On the other hand, the physical adsorbent is preferable because it can remove even a plurality of odor components and has a high effect on the removal of the rotting odor of the body fluid. Also, a physical adsorbent is preferable from an industrial viewpoint such as supply capacity and cost.

  The adsorbent used in the present invention is not particularly limited, and examples thereof include activated carbon, silica gel, zeolite, alumina, bentonite, diatomaceous earth and bauxite. Among these, activated carbon and silica gel are preferable, and activated carbon is more preferable from the viewpoint of versatility with respect to adsorption capacity and odor, and industrial viewpoints such as supply capacity and cost.

  The size of the adsorbent used is not particularly limited as long as it is the size of a commodity handled as powder in the market. From the viewpoint of reducing the feeling of foreign matter during mounting, for example, an adsorbent having a size that passes through a JIS standard sieve having an aperture of 600 μm is preferable.

The content of the adsorbent is preferably 10 to 200 g (that is, 10 to 200 g / m) per square meter of the water absorbent sheet structure from the viewpoint of obtaining deodorizing performance when the water absorbent sheet structure is used in an absorbent article. ² ), more preferably 20 to 180 g / m ² , still more preferably 30 to 150 g / m ² . The content is preferably 10 g / m ² or more from the viewpoint of exhibiting sufficient deodorizing performance as a water absorbent sheet structure, and is cost effective for fixing to the water absorbent sheet structure and deodorizing performance. Therefore, the content is preferably 200 g / m ² or less.

  Examples of the adhesive used in the water-absorbent sheet structure according to the present invention include rubber adhesives such as natural rubber, butyl rubber and polyisoprene; styrene-isoprene block copolymer (SIS) and styrene-butadiene block. Styrenic elastomer adhesives such as polymer (SBS), styrene-isobutylene block copolymer (SIBS), styrene-ethylene-butylene-styrene block copolymer (SEBS); ethylene-vinyl acetate copolymer (EVA) adhesion Agent: ethylene-acrylic acid copolymer copolymer adhesive such as ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA); ethylene-acrylic acid copolymer (EAA) adhesive Polyamide adhesives such as copolymer nylon and dimer acid-based polyamide; Examples include polyolefin adhesives such as reethylene, polypropylene, atactic polypropylene, and copolymerized polyolefins; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester adhesives such as copolymerized polyester, and acrylic adhesives. It is done. In the present invention, the adhesive strength is strong, and it is possible to prevent the peeling of the nonwoven fabric in the water absorbent sheet structure and the dissipation of the water absorbent resin and the adsorbent. Agents, polyolefin adhesives and polyester adhesives are preferred. These adhesives may be used alone or in combination of two or more.

  The adhesive is used for forming a primary liquid absorption layer, a secondary liquid absorption layer, and an adsorption layer. The type, combination, amount, and the like of the adhesive used for forming each layer may be the same or different in each layer.

  When using a hot-melt adhesive, the melting temperature or softening point of the adhesive is preferably from the viewpoint of sufficiently fixing the water-absorbent resin or adsorbent to the nonwoven fabric and preventing thermal deterioration and deformation of the nonwoven fabric. It is 50-180 degreeC, More preferably, it is 70-150 degreeC.

  The content ratio of the adhesive in the water absorbent sheet structure is preferably in the range of 0.05 to 2.0 times, more preferably 0, relative to the total content (mass basis) of the water absorbent resin and the adsorbent. The range is 0.08 to 1.5 times, and more preferably 0.1 to 1.0 times. From the viewpoint of preventing peeling of the nonwoven fabric and dissipation of the water-absorbent resin and the adsorbent by sufficient adhesion, and increasing the form retention of the water-absorbent sheet structure, the content ratio of the adhesive is preferably 0.05 times or more, From the viewpoint of avoiding swelling inhibition of the water-absorbent resin due to excessive adhesion and improving the liquid permeation rate and liquid leakage of the water-absorbent sheet structure, the content ratio of the adhesive is preferably 2.0 times or less. .

  The nonwoven fabric used for the water-absorbent sheet structure according to the present invention is not particularly limited as long as it is a known nonwoven fabric in the technical field, but from the viewpoint of liquid permeability, flexibility, and form retention when a sheet structure is formed. Polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN), polyamide fibers such as nylon, rayon fibers, etc. Non-woven fabrics made of synthetic fibers, and non-woven fabrics manufactured by mixing cotton, silk, hemp, pulp (cellulose) fibers and the like. Among these non-woven fabrics, synthetic fiber non-woven fabrics are preferably used from the viewpoint of enhancing the shape retention of the water-absorbent sheet structure, and in particular, non-woven fabrics containing rayon fibers, polyolefin fibers, and polyester fibers are preferable. These non-woven fabrics may be a single non-woven fabric of the above fibers or a non-woven fabric combining two or more kinds of fibers.

  More specifically, manufactured from fibers selected from the group consisting of polyolefin fibers, polyester fibers, and mixtures thereof, from the viewpoint of enhancing the shape retention of the water absorbent sheet structure and preventing the water-absorbent resin from falling off due to the omission. The spunbond nonwoven fabric is more preferable, and from the viewpoint of further improving the liquid absorption performance and flexibility when forming the sheet, a spunlace nonwoven fabric mainly composed of rayon fibers and an air-through nonwoven fabric of polyolefin fibers are also included in the present invention. The nonwoven fabric used is more preferable. Among the above-mentioned spunbond nonwoven fabrics, a spunbond-meltblown-spunbond (SMS) nonwoven fabric and a spunbond-meltblown-meltblown-spunbond (SMMS) nonwoven fabric, which are multilayer structures of polyolefin fibers, are more preferably used, especially polypropylene. SMS nonwoven fabrics and SMMS nonwoven fabrics mainly composed of fibers are preferably used. On the other hand, as the spunlace nonwoven fabric, those in which polyolefin fibers and / or polyester fibers are appropriately blended with the main component rayon fibers are preferably used, and in particular, rayon-PET nonwoven fabric and rayon-PET-PE nonwoven fabric are preferably used. The nonwoven fabric may contain a small amount of pulp fiber to the extent that the thickness of the water-absorbent sheet structure is not increased.

  If the non-woven fabric is too low in hydrophilicity, the liquid absorbing performance of the water-absorbing sheet structure deteriorates.On the other hand, even if it is higher than necessary, the liquid absorbing performance is not improved to the extent that it has an appropriate hydrophilicity. It is desirable. From that point of view, a hydrophilicity of 5 to 200 is preferably used, more preferably 8 to 150, and more preferably 10 to 100, as measured according to the measurement method of “hydrophilicity of nonwoven fabric” described later. More preferably, the thing of 12-80 is still more preferable. Such a non-woven fabric having hydrophilicity is not particularly limited. Among the above-described non-woven fabrics, those using a material having an appropriate hydrophilicity such as rayon fibers may be used, and polyolefin fibers and polyester fibers may be used. Such a hydrophobic chemical fiber may be subjected to a hydrophilization treatment by a known method to give an appropriate degree of hydrophilicity. Examples of the hydrophilization treatment method include, for example, a method of obtaining a nonwoven fabric by a spunbond method in which a hydrophilic chemical agent is mixed with a hydrophobic chemical fiber in a spunbond nonwoven fabric, or a spunbond nonwoven fabric is prepared by using a hydrophobic chemical fiber. Examples of the method include a method in which a hydrophilizing agent is accompanied, or a method in which a spunbonded nonwoven fabric is obtained with hydrophobic chemical fibers and then impregnated with the hydrophilizing agent. Hydrophilic agents include anionic surfactants such as aliphatic sulfonates and higher alcohol sulfate esters, cationic surfactants such as quaternary ammonium salts, polyethylene glycol fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acids Nonionic surfactants such as esters, silicone surfactants such as polyoxyalkylene-modified silicones, and stain release agents composed of polyester, polyamide, acrylic, and urethane resins are used.

  The nonwoven fabric sandwiching the absorbent layer is preferably hydrophilic from the viewpoint of further improving the liquid absorption performance of the water absorbent sheet structure, but in particular, from the viewpoint of preventing liquid leakage, the nonwoven fabric used below the absorbent layer. The hydrophilicity is more preferably equal to or higher than the hydrophilicity of the nonwoven fabric used above. In the present specification, the upper side of the absorbent layer means the side to which the liquid to be absorbed is supplied when the absorbent article is produced using the resulting water absorbent sheet structure, and the lower side of the absorbent layer is the opposite side. Say.

The nonwoven fabric is appropriately bulky from the viewpoint of imparting good liquid permeability, flexibility, form retention and cushioning properties to the water absorbent sheet structure according to the present invention, and increasing the liquid penetration rate of the water absorbent sheet structure. Nonwoven fabrics that are high and have a large basis weight are preferred. The basis weight is preferably 5 to 300 g / m ² , more preferably 8 to 200 g / m ² , further preferably 10 to 100 g / m ² , and still more preferably 11 to 50 g / m ^2. It is. Moreover, as thickness of a nonwoven fabric, Preferably it is the range of 20-800 micrometers, More preferably, it is the range of 50-600 micrometers, More preferably, it is the range of 80-450 micrometers. As a method for measuring the thickness of the nonwoven fabric, a method for measuring the thickness of the water-absorbent sheet structure described below in the dry state can be employed.

  The absorbent layer of the water absorbent sheet structure according to the present invention is composed of two liquid absorbent layers and an adsorption layer. From the viewpoint of improving the performance and stabilizing the quality of the water absorbent sheet structure, the primary liquid absorbent layer, A structure in which the liquid layer and the adsorption layer are not substantially mixed is more preferable, and a fractionated structure is further preferable. Here, “substantially not mixed” means that the primary liquid-absorbing layer, the secondary liquid-absorbing layer, and the adsorbing layer do not interfere with each other, and “fractionated” means that This means that the primary liquid-absorbing layer, the secondary liquid-absorbing layer, and the adsorbing layer are individually formed by immobilizing individual layers by sequential bonding or mixing the fractionation layer. Examples of such a substantially non-mixing structure include a structure in which a primary liquid absorption layer, a secondary liquid absorption layer, and an adsorption layer are individually laminated and bonded, and a primary liquid absorption layer and a secondary liquid absorption. Examples include a structure in which a layer and an adsorption layer are separated by a gas-permeable fraction layer and bonded.

  The air-permeable fraction layer has an appropriate air-permeability and liquid permeability, but may be any layer as long as particulate matter such as a water-absorbent resin or an adsorbent does not substantially pass therethrough. Specifically, nets such as nets having pores made of PE and PP fibers, porous films such as performance films, sanitary papers such as tissue paper, airlaid nonwoven fabrics made of pulp / PE / PP, etc. Examples thereof include a cellulose-containing synthetic fiber nonwoven fabric or a synthetic fiber nonwoven fabric made of rayon fiber, polyolefin fiber and polyester fiber. Among these air-permeable fraction layers, the same nonwoven fabric as that sandwiching the absorbent layer in the present invention is preferably used from the viewpoint of the performance of the water-absorbent sheet structure to be obtained.

  The absorbent layer of the water absorbent sheet structure according to the present invention is composed of 1) a primary liquid absorbent layer containing a water absorbent resin, 2) a secondary liquid absorbent layer containing a water absorbent resin, and 3) an adsorption layer containing an adsorbent. One feature is that the adsorption layer exists between the secondary liquid absorption layer and the nonwoven fabric.

  By forming such a configuration, body fluids such as urine and blood are positioned in the vertical direction (thickness direction of the water-absorbing sheet structure) in the upper primary liquid absorbing layer and the secondary liquid absorbing layer located below the primary liquid absorbing layer. Body fluid to the adsorption layer located below the secondary liquid absorption layer by the secondary liquid absorption layer that is diffused and absorbed by the liquid absorption layer and is formed from a water absorbent resin having a saline water absorption speed of 1 to 15 seconds. Can be suppressed. As a result, the adsorbent comes into contact with bodily fluids such as urine and blood, and it is possible to minimize a decrease in the deodorizing effect of the adsorbent due to adsorption of moisture, proteins, etc. in the bodily fluid, and the formed adsorption layer It is possible to prevent odors that are continuously generated.

  The water-absorbent sheet structure according to the present invention can be produced, for example, by the following method using a conventional method.

(A) On a nonwoven fabric, a mixed powder of a water-absorbent resin and an adhesive is uniformly dispersed, and after passing through a heating furnace and fixed to such an extent that the powder is not dispersed, a mixed powder containing a water-absorbing resin different from the above is prepared. After spraying and fixing the powder in the same manner, the mixed powder containing the adsorbent is sprayed again, and the non-woven fabrics stacked are thermocompression bonded together.

(B) On the non-woven fabric, uniformly spray the mixed powder of the water absorbent resin and the adhesive, then spray the mixed powder containing the water absorbent resin different from the above, and again spray the mixed powder containing the adsorbent. Then, the non-woven fabrics are heat bonded together. (In this method, in order to avoid mixing each layer, it is preferable to spray a mixed powder containing a material having a large specific gravity and then spraying a mixed powder containing a material having a low specific gravity.)

(C) On the non-woven fabric, uniformly spray the mixed powder of the water absorbent resin and the adhesive, and after further stacking the air-permeable fraction layer, then spray the mixed powder containing the water absorbent resin different from the above, After the breathable fraction layers are stacked, the mixed powder containing the adsorbent is again sprayed, and the non-woven fabrics stacked are thermocompression bonded together. (In this method, thermocompression bonding may be applied even after the breathable fraction layers are stacked.)

(D) Immediately after the adhesive is melt-coated on the nonwoven fabric, the water-absorbing resin is uniformly dispersed to form a layer, and the adhesive is melt-coated from above to fix the water-absorbing resin. The same operation is again performed on this intermediate using a water absorbent resin and an adsorbent different from those described above.

  For example, a structure in which the primary liquid-absorbing layer, the secondary liquid-absorbing layer, and the adsorbing layer are not substantially mixed is achieved by manufacturing the water-absorbing sheet structure by the methods shown in (a) to (d). be able to. Among the above methods, the methods (a), (c) and (d) are more preferable from the viewpoint that the primary liquid absorption layer, the secondary liquid absorption layer, and the adsorption layer can be fractionated. From the viewpoint of high efficiency, the methods (a) and (d) are more preferable.

  In addition, it can also manufacture by selecting separately the adhesion method of two liquid absorption layers and adsorption layers from the method illustrated to (a)-(d), and combining. For the purpose of improving the tactile sensation and strength of the water-absorbent sheet structure, embossing may be performed at the time of thermocompression bonding or after sheet manufacture.

  Moreover, the water absorbent sheet structure according to the present invention may contain additives such as antibacterial agents and gel stabilizers as appropriate.

  The water absorbent sheet structure according to the present invention has one feature in that it can be thinned, and considering the use for absorbent articles, the thickness of the water absorbent sheet structure is 5 mm in a dry state. The following is preferable, 4 mm or less is more preferable, and 1.0-3.0 mm is further more preferable. In addition, a dry state means the state before a water absorbing sheet structure body absorbs a liquid. In the present specification, the dry thickness of the water absorbent sheet structure is a value obtained by the measurement method described in the examples described later.

  Furthermore, the water absorbent sheet structure according to the present invention has one feature in that the liquid permeation rate is high, and the total permeation rate of the water absorbent sheet structure is 120 seconds or less in consideration of use in absorbent articles. It is preferably 110 seconds or less, more preferably 100 seconds or less. In the present specification, the total permeation rate of the water absorbent sheet structure is a value obtained by the measurement method described in Examples described later.

  Furthermore, the water absorbent sheet structure according to the present invention has one feature in that the liquid leakage of the liquid is small, and considering the use for absorbent articles, the leakage index in the inclination of the water absorbent sheet structure is 100 or less. Preferably, it is 60 or less, more preferably 40 or less. In the present specification, the leakage index in the inclination of the water absorbent sheet structure is a value obtained by the measurement method described in Examples described later.

  The water absorbent sheet structure according to the present invention preferably has a dry state thickness, a total permeation rate, and a leak index at a slope satisfying all predetermined characteristics.

  Furthermore, since the water-absorbent sheet structure according to the present invention uses a very small amount of a naturally-derived material, the above-described thickness, permeation rate, and leakage index are high-performance and environmentally conscious. The ratio of the natural material is preferably 30% or less, more preferably 20% or less, and further preferably 15% or less. The ratio of the natural material is calculated by dividing the total content of pulp, cotton, etc. contained in the constituent components of the water-absorbing sheet constituent in a small amount by the mass of the water-absorbing sheet constituent.

  A water absorbent sheet structure satisfying all the properties as described above is very preferable in consideration of use in absorbent articles.

  Next, the structure of the water absorbent sheet structure according to the present invention will be described with reference to FIG. Here, FIG. 1 is an enlarged cross-sectional view schematically showing the structure of the water absorbent sheet structure according to the present invention.

  A water absorbent sheet structure 10 shown in FIG. 1 includes a primary liquid absorbent layer 13 containing a water absorbent resin 12 and an adhesive 11, and a secondary liquid absorbent containing a water absorbent resin 14 and an adhesive 11. It has a layer 15 and an adsorption layer 17 containing the adsorbent 16 and the adhesive 11. Here, the primary liquid-absorbing layer refers to the side to which the liquid to be absorbed is supplied when the absorbent article is prepared using the water-absorbent sheet structure, and the secondary liquid-absorbing layer is the primary liquid-absorbing layer. The side to which the liquid to be absorbed is supplied through the layer.

  In FIG. 1, the two liquid absorption layers and the adsorption layer are divided into a primary liquid absorption layer, a secondary liquid absorption layer, and an adsorption layer so as not to be substantially mixed. The water absorbent sheet structure 10 in FIG. 1 includes a primary liquid absorbent layer 13, a secondary liquid absorbent layer 15 and an adsorption layer 17, and nonwoven fabrics 18 and 19 located on the outer surfaces of the primary liquid absorbent layer 13 and the adsorption layer 17, respectively. It is a five-layer structure consisting of two front and back layers, and the absorbent layer is sandwiched by nonwoven fabrics 18 and 19 from above and below the absorbent layer.

  Moreover, the water absorbing sheet structure shown in FIG. 2 is also an example of another form of the water absorbing sheet structure according to the present invention. FIG. 2 shows an example in which the adhesive 20 is melt-coated on the nonwoven fabric 18 and the like, and the two liquid-absorbing layers and the adsorbing layer are fractionated by the air-permeable fraction layer 21.

  The absorbent article according to the present invention can be obtained by sandwiching the water absorbent sheet structure according to the present invention between the liquid permeable sheet and the liquid impermeable sheet. As the liquid permeable sheet and the liquid impermeable sheet, those known in the technical field of absorbent articles can be used without particular limitation. Moreover, this absorbent article can be manufactured by a well-known method.

  Examples of the absorbent article include paper diapers, incontinence pads, sanitary napkins, pet sheets, food drip sheets, and the like.

  Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

  The performance of the water absorbent resin and the water absorbent sheet structure was measured by the following method.

<Saline retention capacity of water-absorbent resin>
2.0 g of the water-absorbent resin was weighed into a cotton bag (Membroad No. 60, width 100 mm × length 200 mm) and placed in a 500 mL beaker. 500 g of physiological saline (0.9% by mass sodium chloride aqueous solution, the same applies hereinafter) was poured into a cotton bag at a time, and the physiological saline was dispersed so as not to generate water-absorbent resin mamako. The upper part of the cotton bag was tied with a rubber band and left for 1 hour to sufficiently swell the water absorbent resin. The cotton bag was dehydrated for 1 minute using a dehydrator (product number: H-122, manufactured by Kokusan Centrifuge Co., Ltd.) set to have a centrifugal force of 167 G, and the weight Wa of the cotton bag containing the swollen gel after dehydration ( g) was measured. The same operation was performed without adding the water absorbent resin, the wet hourly space mass Wb (g) of the cotton bag was measured, and the physiological saline water retention capacity of the water absorbent resin was determined by the following formula.
Water retention capacity of water-absorbent resin (g / g) = [Wa-Wb] (g) / mass of water-absorbent resin (g)

<Saline water absorption rate of water-absorbing resin>
This test was conducted in a room adjusted to 25 ° C. ± 1 ° C. In a 100 mL beaker, 50 ± 0.1 g of physiological saline is weighed, a magnetic stirrer bar (without 8 mmφ × 30 mm ring) is added, the beaker is immersed in a constant temperature water bath, and the liquid temperature is 25 ± 0. Adjusted to 2 ° C. Next, after placing a beaker on a magnetic stirrer and generating a vortex in physiological saline at a rotation speed of 600 r / min, 2.0 ± 0.002 g of a water absorbent resin is quickly added to the beaker, Using a stopwatch, the time (seconds) from the addition of the water-absorbing resin to the point at which the vortex on the liquid surface converges was measured and used as the water-absorption rate of the water-absorbing resin.

<Medium particle size of water absorbent resin>
Unless otherwise specified, the particle size of the water-absorbent resin was defined as the median particle size and measured as follows.

  To 50 g of the water absorbent resin, 0.25 g of amorphous silica (Degussa Japan Co., Ltd., Siperant 200) was mixed as a lubricant.

  When the water-absorbing resin is passed through a JIS standard sieve having a mesh size of 250 μm and 50% by mass or more of the water-absorbent resin passes, the combination of sieves in (A) is used. When remaining, the median particle size was measured using the combination of sieves (B).

  (A) JIS standard sieve from above, sieve with 425 μm openings, sieve with 250 μm openings, sieve with 180 μm openings, sieves with 150 μm openings, sieves with 106 μm openings, sieves with 75 μm openings, 45 μm openings Combined in order of sieve and saucer.

  (B) JIS standard sieve from above, sieve with an opening of 850 μm, sieve with an opening of 600 μm, sieve with an opening of 500 μm, sieve with an opening of 425 μm, sieve with an opening of 300 μm, sieve with an opening of 250 μm, sieve with an opening of 150 μm Combined in order of sieve and saucer.

  The water-absorbing resin was put into the combined uppermost sieve and classified by shaking for 20 minutes using a low-tap shaker.

  After classification, the mass of the water-absorbent resin remaining on each sieve is calculated as a percentage by mass with respect to the total amount, and the mass of the water-absorbent resin remaining on the sieve opening and the sieve is calculated by integrating in order from the larger particle size. The relationship between percentage and integrated value was plotted on a logarithmic probability paper. By connecting the plots on the probability paper with a straight line, the particle diameter corresponding to an integrated mass percentage of 50 mass% was defined as the median particle diameter.

<Hydrophilicity of nonwoven fabric>
In the present specification, the hydrophilicity of the nonwoven fabric is determined by the paper pulp test method No. 68 (2000) and measured using the apparatus described in “Water Repellency Test Method”.

  In other words, a test piece attachment device having a 45 ° inclination and a strip shape having a width × length of 10 cm × 30 cm and cut so that the longitudinal direction is the longitudinal direction (machine direction) of the nonwoven fabric was attached. The burette was adjusted to supply 10 g of distilled water per 30 seconds to the burette cock opening once dried, and the tip of the burette was 5 mm vertically above the top of the test piece attached to the inclined device. Fixed to place. Approximately 60 g of distilled water is charged from the upper part of the burette, and the time (seconds) from when the liquid starts dripping from the burette tip to the nonwoven fabric test piece until the test piece cannot hold the liquid and the liquid leaks from the lower part is measured. The hydrophilicity of the nonwoven fabric was used. It is judged that the hydrophilicity is higher as the numerical value is larger.

  In general, the nonwoven fabric material itself has hydrophilicity or a hydrophilicity-treated nonwoven fabric has a hydrophilicity value of 5 or more, whereas a nonwoven material with low hydrophilicity has liquid running near the surface, and more There is a tendency for liquid to leak quickly from the bottom.

<Measurement of dry thickness of water absorbent sheet structure>
A sample having a strip shape of 10 cm × 30 cm and cut so that the longitudinal direction is the longitudinal direction (machine direction) of the nonwoven fabric was used as a sample. Using a thickness measuring instrument (manufactured by Ozaki Mfg. Co., Ltd., model number: J-B), the left end, the center, and the right end in the longitudinal direction were measured (3 cm from the left, 3 cm from the left, 15 cm from the center, and 27 cm from the right end). The width direction measured the center part. The measured thickness was measured three times at each location and averaged. Furthermore, the values of the left end, the center, and the right end were averaged to obtain the thickness of the entire water absorbent sheet structure in the dry state.

<Evaluation of total permeation rate and reversal amount of water absorbent sheet structure>
A sample formed by cutting the water-absorbing sheet structure into a strip of 10 × 30 cm so that the longitudinal direction is the longitudinal direction (machine direction) of the nonwoven fabric was used as a sample.

  In a 10 L container, 60 g of sodium chloride, 1.8 g of calcium chloride dihydrate, 3.6 g of magnesium chloride hexahydrate and an appropriate amount of distilled water were added and completely dissolved. Next, 15 g of a 1% by mass poly (oxyethylene) isooctylphenyl ether aqueous solution was added, and distilled water was further added to adjust the mass of the entire aqueous solution to 6000 g. A test solution was prepared.

A polyethylene air-through porous liquid permeable sheet having the same size (10 × 30 cm) as the sample and a basis weight of 22 g / m ² was placed on the upper part of the sample (water-absorbing sheet structure). Further, a polyethylene liquid-impermeable sheet having the same size and basis weight as this sheet was placed under the sample to prepare a simple absorbent article. A cylindrical cylinder with an inner diameter of 3 cm is placed near the center of this body fluid absorbent article, and 50 mL of the test liquid is added at once, and the test liquid completely penetrates into the body fluid absorbent article using a stopwatch. Was measured as the first permeation rate (seconds). Next, the same operation was performed after 30 minutes and 60 minutes without moving the cylinder position, and the second and third permeation rates (seconds) were measured. The total number of seconds from the first to the third time was taken as the total penetration rate.

The cylinder is removed 120 minutes after the start of the first test liquid charging, and a 10 cm square filter paper (about 70 cm) whose mass (Wc (g), approximately 70 g) has been measured in advance in the vicinity of the liquid charging position on the body fluid absorbent article. 80 pieces) and a 5 kg weight of 10 cm × 10 cm was placed thereon. After loading for 5 minutes, the mass of the filter paper (Wd (g)) was measured, and the increased mass was taken as the reversal amount (g).
Return amount (g) = Wd−Wc

<Leakage test in the inclination of the water absorbent sheet structure>
The leak test at the inclination was performed using the apparatus shown in FIG.

  As an outline, after the acrylic plate 32 is tilted and fixed using a commercially available gantry 31 for experimental equipment, the test solution is dropped onto the absorbent article 33 placed on the plate with a dropping funnel 34 from above vertically. This is a mechanism for measuring the amount of leakage with a balance 35. Detailed specifications are shown below.

  The acrylic plate 32 was 45 cm in length in the direction of the inclined surface and was fixed by the gantry 31 so that the angle formed with respect to the horizontal was 45 ± 2 °. The acrylic plate 32 had a width of 100 cm and a thickness of 1 cm, and it was also possible to measure a plurality of absorbent articles 33 in parallel. Since the surface of the acrylic plate 32 was smooth, no liquid stayed or was absorbed on the plate.

  A dropping funnel 34 was fixed vertically above the inclined acrylic plate 32 using the gantry 31. The dropping funnel 34 had a capacity of 100 mL, an inner diameter of the tip portion of about 4 mm, and the cock throttle was adjusted so that the liquid was introduced at 8 mL / second.

  A balance 35 on which a tray 36 is placed is installed at the lower part of the acrylic plate 32. All of the test liquid that flows down as a leak is received, and its mass is recorded with an accuracy of 0.1 g.

The leak test in the inclination using such an apparatus was performed according to the following procedure. The sample was a water-absorbent sheet structure that was 10 × 30 cm long and was cut so that the longitudinal direction was the longitudinal direction (machine direction) of the hydrophilic nonwoven fabric. Next, an air-through type polyethylene liquid-permeable nonwoven fabric of the same size (weight per unit area 22 g / m ² ) is applied from above the sample, and a polyethylene liquid impervious sheet of the same size and weight per unit is applied from below. The simple absorbent article 33 created in this manner was pasted on the acrylic plate 32 (the lower end of the absorbent article 33 was not pasted on the acrylic plate 32 in order not to stop leakage). .

  A mark was placed at a location 2 cm below the center of the upper end surface of the absorbent article 33, and the inlet of the dropping funnel 34 was fixed so that the vertical distance from the mark was 1 cm.

  After starting the balance 35 and correcting the display to zero, 80 mL of the test solution was put into the dropping funnel 34 at a time. The test liquid flowed through the inclined acrylic plate 32 without being absorbed by the absorbent article 33, and the amount of liquid entering the tray 36 was measured to obtain the first leakage amount (g). The numerical value of the first leakage amount (g) was LW1.

  Similarly, at the interval of 10 minutes from the start of the first injection, the second and third test solutions are similarly supplied, and the second and third leakage amounts (g) are measured. The numerical values are LW2 and LW3, respectively. did.

Next, the leak index at the slope was calculated according to the following formula. As the index approaches zero, the amount of leakage in the inclination of the water absorbent sheet structure, particularly the initial amount of leakage is small, and it is determined that the water absorbent sheet structure is excellent.
Leakage index on slope: L = LW1 × 10 + LW2 × 5 + LW3

<Odor sensory test of water absorbent sheet structure>
50 mL of fresh urine was placed in a 100 mL Meyer flask, 0.25 g of urea and 1 g of pulp collected from used diapers were added, and the solution was allowed to stand for 24 hours to prepare fermented urine. Next, the test solution was prepared by mixing fresh urine and the above fermented urine at a ratio of 9: 1 (mass ratio) (the fresh urine is sterile, so sufficient odor is generated if the fermented urine is not mixed) do not do).

  A sample obtained by cutting the water-absorbing sheet structure into a 5 × 5 cm square was placed in a 250 mL glass bottle as a sample, and then 30 g of the test solution was added to swell the sample. After adding the test solution, it was immediately sealed and stored at 40 ° C. for 24 hours. After storage, five panelists (A to E) were asked to determine the odor in the 250 mL glass bottle according to the following criteria in accordance with the “standard 6-level odor intensity display method” of the standard criteria, and evaluated with the average value. .

(Production Example 1: Production of water absorbent resin A)
As a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, and a stirrer, a round bottom cylindrical separable flask having an inner diameter of 100 mm equipped with a stirring blade having two inclined paddle blades with a blade diameter of 50 mm in two stages was prepared. 500 mL of n-heptane was taken into this flask, 0.92 g of sucrose stearate ester (manufactured by Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) as a surfactant, maleic anhydride-modified ethylene / propylene copolymer 0.92 g of coalescence (manufactured by Mitsui Chemicals, High Wax 1105A) was added, the temperature was raised to 80 ° C. to dissolve the surfactant, and then cooled to 50 ° C.

  On the other hand, after taking 92 g of 80% by mass acrylic acid aqueous solution in a 500 mL Erlenmeyer flask and cooling from the outside, 146.0 g of 21% by mass sodium hydroxide aqueous solution was added dropwise to neutralize 75 mol%, 0.11 g of potassium persulfate and 9.2 mg of N, N′-methylenebisacrylamide were added and dissolved to prepare the first stage monomer.

  The rotation rate of the stirrer was set to 450 r / min, the monomer aqueous solution was added to the separable flask, and the system was replaced with nitrogen, maintained at 35 ° C. for 30 minutes, and then immersed in a 70 ° C. water bath. The temperature was raised and polymerization was performed for 30 minutes to obtain a first post-polymerization slurry.

  On the other hand, 128.8 g of 80 mass% acrylic acid aqueous solution was put into another 500 mL Erlenmeyer flask, and 159.0 g of 27 mass% sodium hydroxide was added dropwise while cooling from the outside to neutralize 75 mol%. Thereafter, 0.16 g of potassium persulfate and 12.9 mg of N, N′-methylenebisacrylamide were added and dissolved to prepare a second-stage monomer aqueous solution, and the temperature was maintained at about 25 ° C.

  The stirring speed of the stirrer containing the slurry after the first stage polymerization was changed to 1000 r / min, then cooled to 25 ° C., the second stage monomer aqueous solution was added to the system, and nitrogen was added. And kept for 30 minutes. Again, the flask was immersed in a 70 ° C. water bath to raise the temperature, and polymerization was performed for 30 minutes to obtain a second-stage post-polymerization slurry.

  Next, the temperature was raised using an oil bath at 120 ° C., and water and n-heptane were azeotroped to extract 220 g of water out of the system while refluxing n-heptane, and then ethylene glycol diglycidyl. 8.17 g of a 2% aqueous solution of ether was added and held at 80 ° C. for 2 hours. Thereafter, n-heptane was evaporated and dried to obtain 230.2 g of a water absorbent resin A. The median particle diameter of the obtained water-absorbent resin was 370 μm, the physiological saline water retention capacity was 37 g / g, and the physiological saline water absorption rate was 39 seconds.

(Production Example 2: Production of water absorbent resin B)
In the production example of the water-absorbent resin A, the rotation speed of the stirrer at the first stage polymerization was changed to 380 r / min, and 2% of ethylene glycol diglycidyl ether added after extracting water out of the system by azeotropy Except having changed the quantity of aqueous solution into 4.42g, operation similar to the manufacture example of the water absorbing resin A was performed, and 231.5g of water absorbing resin B was obtained. The median particle diameter of the obtained water-absorbent resin was 450 μm, the physiological saline water retention capacity was 45 g / g, and the physiological saline water absorption rate was 70 seconds.

(Production Example 3: Production of water absorbent resin C)
In the production example of the water absorbent resin A, the rotation speed of the stirrer at the first stage polymerization was changed to 350 r / min, and 2% of ethylene glycol diglycidyl ether added after water was extracted out of the system by azeotropy Except having changed the amount of aqueous solution into 6.62g, operation similar to the manufacture example of the water absorbent resin A was performed, and 229.8g of water absorbent resin C was obtained. The median particle diameter of the obtained water-absorbent resin was 520 μm, the physiological saline water retention capacity was 43 g / g, and the physiological saline water absorption rate was 82 seconds.

(Production Example 4: Production of water absorbent resin D)
In the production example of the water-absorbent resin A, the cooling temperature of the slurry after the first polymerization was changed to 29 ° C., and 2% of ethylene glycol diglycidyl ether added after extracting water out of the system by azeotropy Except having changed the quantity of aqueous solution into 4.42g, operation similar to the manufacture example of the water absorbing resin A was performed, and 230.5g of water absorbing resin was obtained. The obtained water-absorbing resin was classified using a JIS standard sieve having an opening of 180 μm, and 52.6 g of a water-absorbing resin D obtained by passing through the sieve having an opening of 180 μm was obtained. The median particle diameter of the water-absorbent resin D was 140 μm, the physiological saline water retention capacity was 31 g / g, and the physiological saline water absorption rate was 18 seconds.

(Production Example 5: Production of water absorbent resin E)
As a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, and a stirrer, a round bottom cylindrical separable flask having an inner diameter of 100 mm equipped with a stirring blade having two inclined paddle blades with a blade diameter of 50 mm in two stages was prepared. Take 550 mL of n-heptane to this flask, add 0.84 g of HLB8.6 sorbitan monolaurate (manufactured by NOF Corporation, Nonion LP-20R) as a surfactant, and heat up to 50 ° C. to obtain surface activity. After dissolving the agent, it was cooled to 40 ° C.

  On the other hand, 70 g of 80 mass% acrylic acid aqueous solution was put into a 500 mL Erlenmeyer flask, and 111.0 g of 21 mass% sodium hydroxide aqueous solution was added dropwise to neutralize 75 mol%, and then 0.084 g of potassium persulfate was added. In addition, it melt | dissolved and prepared monomer aqueous solution.

  The rotation speed of the stirrer was set to 800 r / min, the monomer aqueous solution was added to the separable flask, the inside of the system was replaced with nitrogen for 30 minutes, and then the temperature was increased by immersion in a 70 ° C. water bath. For 2 hours.

  Next, the temperature was raised using an oil bath at 120 ° C., and 85.0 g of water was withdrawn from the system while refluxing n-heptane by azeotropically distilling water and n-heptane. 3.50 g of a 2% aqueous solution of glycidyl ether was added and held at 80 ° C. for 2 hours. Then, 72.0 g of water-absorbing resin E was obtained by evaporating n-heptane and drying. The obtained water-absorbent resin E had a median particle size of 230 μm, a physiological saline water absorption capacity of 37 g / g, and a physiological saline water absorption rate of 3 seconds.

Example 1
A hydrobonding treatment of a 30 cm wide spunbond-meltblown-spunbond (SMS) non-woven fabric with a hydrophilizing agent on a hot melt coating machine (Harry's: Marshall 150) set at a heating temperature of 150 ° C. ( Fiber: Polypropylene, basis weight 13 g / m ² , thickness: 150 μm, hydrophilicity = 16; “nonwoven fabric A”) is spread, and then a styrene-butadiene block copolymer (softening point 85 ° C .; SBS ”) was applied onto the nonwoven fabric at a basis weight of 20 g / m ² .

Next, the water-absorbent resin A obtained in Production Example 1 was charged as a water-absorbent resin into the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C). On the other hand, the adhesive-coated non-woven fabric was laid on a conveyor below the spreader. Subsequently, the water-absorbing resin A was uniformly laminated on the nonwoven fabric at a basis weight of 200 g / m ² by operating the spraying roller and the lower conveyor.

The obtained laminate was spun lace nonwoven fabric (fiber: rayon / PET, thickness: 300 μm) as a breathable fraction layer in which the SBS as an adhesive was applied from the top at a basis weight of 20 g / m ² in the same manner as described above. , Weight per unit area: 35 g / m ² , hydrophilicity = 38; “nonwoven fabric B”) and then laminating machine set to 100 ° C. (manufactured by HASHIMA Co., Ltd .: linear adhesive press HP-600LF) These were integrated by heat-sealing to obtain a water-absorbing sheet constituting intermediate having a primary liquid-absorbing layer.

Similarly to the above, on the hot melt coating machine set at a heating temperature of 150 ° C., the intermediate body of the water absorbent sheet is laid so that the nonwoven fabric B side is the upper part, and the basis weight of the SBS is 5 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin E obtained in Production Example 5 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin E was uniformly laminated on the non-woven fabric B of the intermediate body of the water-absorbing sheet with a basis weight of 50 g / m ² by operating the spray roller and the lower conveyor.

A laminate in which the obtained laminate was sandwiched by another nonwoven fabric B coated with the SBS in the same manner as described above at a basis weight of 5 g / m ² from the top, and then the heating temperature was set to 100 ° C. as described above. These were integrated by heat fusion with a machine to obtain a water absorbent sheet constituting intermediate having a secondary liquid absorbing layer.

In the same manner as described above, a water absorbent sheet constituting intermediate is laid on a hot melt coating machine set at a heating temperature of 150 ° C. so that the nonwoven fabric B side is at the top, and the basis weight of SBS is 10 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, activated carbon (granular white birch GM2x (manufactured by Nippon Enviro Chemicals Co., Ltd.) as an adsorbent and passed through a JIS standard sieve with an opening of 600 μm at the inlet of the roller-type spreader; “activated carbon” And). On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Then, the activated carbon was uniformly laminated | stacked on the nonwoven fabric B of the said water-absorbing sheet structure intermediate body with a fabric weight of 100 g / m < ² > by operating a spreading | diffusion roller and a lower conveyor. In this way, an adsorption layer composed of activated carbon and an adhesive was formed.

A laminate in which the obtained laminate was sandwiched by another non-woven fabric A coated with the SBS in the same manner as described above at a basis weight of 10 g / m ² from the top, and the heating temperature was set to 100 ° C. as described above. These were integrated by heat fusion with a machine to obtain a water-absorbent sheet structure having an adsorption layer. If the cross section of the structure of the obtained water-absorbing sheet structure is schematically shown, it is a structure as shown in FIG.

  The obtained water absorbent sheet structure was cut into a predetermined size, and the various measurements and evaluations were performed with the absorbent layer (primary liquid absorbent layer) using the water absorbent resin A facing upward. The results are shown in Tables 3 and 4.

(Example 2)
30 parts by mass of an ethylene-vinyl acetate copolymer (melting temperature 95 ° C .; referred to as “EVA”) as an adhesive at the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C) and water absorption What mixed uniformly 100 mass parts of water-absorbent resin B obtained by manufacture example 2 as a property resin was prepared. On the other hand, a non-woven fabric B having a width of 30 cm was laid on the conveyor below the spreader. Subsequently, the mixture was uniformly laminated on the non-woven fabric with a weight per unit area of 130 g / m ² by operating a spray roller and a lower conveyor. The obtained laminate is passed through a heating furnace (set temperature: 110 ° C.) attached to the roller-type spreader using a conveyor, and then cooled to room temperature, thereby forming a water absorbing layer in which a primary liquid absorbing layer is formed. A sheet construction intermediate was obtained.

Separately, an adhesive in which 15 parts by mass of EVA and 50 parts by mass of water-absorbing resin E were uniformly mixed was charged into the inlet of the roller-type spreader. Laying the intermediate body of the water absorbent sheet on the conveyor of the roller type spreader so that the primary liquid absorption layer is at the top, and operating the spray roller and the lower conveyor, the weight of the mixture is 65 g / m ^2. And uniformly laminated on the primary liquid absorption layer. Like the above, the obtained laminate is passed through a heating furnace (set temperature 110 ° C.) attached to the roller-type spreader using a conveyor, and then cooled to room temperature, whereby a secondary liquid absorption layer A water-absorbent sheet structure intermediate was formed.

Separately, a material in which 30 parts by mass of EVA and 100 parts by mass of activated carbon were uniformly mixed as an adhesive was charged into the inlet of the roller-type spreader. The mixture of the water-absorbing sheet component is laid on a conveyor of a roller-type spreader so that the secondary liquid-absorbing layer is on the upper side, and the spray roller and the lower conveyor are operated, whereby the weight of the mixture is 130 g / m ^2. And uniformly laminated on the secondary liquid absorption layer. In this way, an adsorption layer composed of activated carbon and an adhesive was formed.

  The obtained laminate is sandwiched from the upper part with the nonwoven fabric B, and further integrated by heat-sealing with a laminating machine (manufactured by HASHIMA CORPORATION: linear adhesive press HP-600LF) set to a heating temperature of 130 ° C. Thus, a water absorbent sheet structure was obtained. If the cross section of the structure of the obtained water-absorbing sheet structure is schematically shown, it is a structure as shown in FIG.

  The obtained water absorbent sheet structure was cut into a predetermined size, and the various measurements and evaluations were performed so that the absorbent layer (primary liquid absorbent layer) using the water absorbent resin B was on the upper side. The results are shown in Tables 3 and 4.

(Example 3)
A non-woven fabric A having a width of 30 cm was laid on a hot melt coating machine (Harry's Co., Ltd .: Marshall 150) set at a heating temperature of 150 ° C., and then SBS (softening point 85 ° C.) as an adhesive was 30 g / weight. It was coated onto the nonwoven m ^2.

Next, the water-absorbent resin A obtained in Production Example 1 was charged as a water-absorbent resin into the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C). On the other hand, the adhesive-coated non-woven fabric was laid on a conveyor below the spreader. Subsequently, the water-absorbing resin A was uniformly laminated on the nonwoven fabric at a basis weight of 600 g / m ² by operating the spraying roller and the lower conveyor.

An air-through nonwoven fabric (fiber: polypropylene / polyethylene with a hydrophilizing agent) was formed as a breathable fraction layer in which the obtained laminate was coated with the SBS as an adhesive in the same manner as described above at a basis weight of 30 g / m ^2. Laminated machine (corporation, Inc.) after being sandwiched by a hydrophilized material, thickness: 150 μm, basis weight: 23 g / m ² , hydrophilicity = 33; “nonwoven fabric C”) These were integrated by heat fusion using a linear adhesive press HP-600LF (Hashima) to obtain a water-absorbent sheet structure intermediate having a primary liquid-absorbing layer.

In the same manner as described above, a water absorbent sheet constituting intermediate is laid on a hot melt coating machine set at a heating temperature of 150 ° C. so that the nonwoven fabric C side is at the top, and the basis weight of the SBS is 6 g / m ² as an adhesive. It applied on the nonwoven fabric C of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin E obtained in Production Example 5 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin E was uniformly laminated on the non-woven fabric C of the intermediate body of the water-absorbent sheet structure with a basis weight of 120 g / m ² by operating the spreading roller and the lower conveyor.

A laminate obtained by sandwiching the obtained laminate with another nonwoven fabric C coated with the SBS in the same manner as described above at a basis weight of 6 g / m ² from the top, and then setting the heating temperature to 100 ° C. as described above These were integrated by heat fusion with a machine to obtain a water absorbent sheet constituting intermediate having a secondary liquid absorbing layer.

In the same manner as described above, a water absorbent sheet constituting intermediate is laid on a hot melt coating machine set at a heating temperature of 150 ° C. so that the nonwoven fabric C side is at the top, and the basis weight of SBS is 3 g / m ² as an adhesive. It applied on the nonwoven fabric C of a water absorbing sheet structure intermediate body.

Next, activated carbon was charged as an adsorbent into the inlet of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Then, the activated carbon was uniformly laminated | stacked on the nonwoven fabric C of the said water absorbent sheet structure intermediate body by the operating amount of 60 g / m < ² > by operating a spreading roller and a lower conveyor. In this way, an adsorption layer composed of activated carbon and an adhesive was formed.

A laminate in which the obtained laminate was sandwiched by another nonwoven fabric A coated with the SBS in the same manner as described above at a basis weight of 3 g / m ² from the top, and then the heating temperature was set to 100 ° C. as described above. These were integrated by heat fusion with a machine to obtain a water-absorbent sheet structure having an adsorption layer. If the cross section of the structure of the obtained water-absorbing sheet structure is schematically shown, it is a structure as shown in FIG.

  The obtained water absorbent sheet structure was cut into a predetermined size, and the various measurements and evaluations were performed with the absorbent layer (primary liquid absorbent layer) using the water absorbent resin A facing upward. The results are shown in Tables 3 and 4.

Example 4
In Example 1, the amount of activated carbon used as the adsorbent is 150 g / m ² , the amount of the adhesive SBS applied to the nonwoven fabric B of the intermediate body of the water absorbent sheet having the secondary liquid absorption layer is 15 g / m ² , A water absorbent sheet structure was obtained in the same manner as in Example 1 except that the amount of the adhesive SBS applied to the nonwoven fabric A to be applied was changed to 15 g / m ² .

(Example 5)
In Example 1, the amount of activated carbon used as the adsorbent is 60 g / m ² , the amount of the adhesive SBS applied to the nonwoven fabric B of the intermediate body of the water-absorbent sheet having the secondary liquid-absorbing layer is 6 g / m ² , A water absorbent sheet structure was obtained in the same manner as in Example 1 except that the amount of the adhesive SBS applied to the nonwoven fabric A to be applied was changed to 6 g / m ² .

(Example 6)
In Example 1, instead of activated carbon as an adsorbent, silica gel (manufactured by Wako Pure Chemical Industries, Ltd .: small particle size 1 to 2 mm) was pulverized and passed through a JIS standard sieve having an aperture of 600 μm (“silica gel” and A water-absorbent sheet structure was obtained by the same method as in Example 1 except that was used.

  The water absorbent sheet structure obtained in Examples 4 to 6 was cut into a predetermined size, and the above various measurements were performed so that the absorbent layer (primary liquid absorbent layer) using the water absorbent resin A was on the upper side. Evaluation was performed. The results are shown in Tables 3 and 4.

(Comparative Example 1)
A non-woven fabric A having a width of 30 cm was laid on a hot melt coating machine (Harrys Co., Ltd .: Marshall 150) set at a heating temperature of 150 ° C., and then SBS (softening point 85 ° C.) as an adhesive was 20 g / weight. It was coated onto the nonwoven m ^2.

Next, the water-absorbent resin A obtained in Production Example 1 was charged as a water-absorbent resin into the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C). On the other hand, the adhesive-coated non-woven fabric was laid on a conveyor below the spreader. Subsequently, the water-absorbing resin A was uniformly laminated on the nonwoven fabric at a basis weight of 200 g / m ² by operating the spraying roller and the lower conveyor.

The obtained laminate was sandwiched between nonwoven fabrics B as an air-permeable fraction layer in which the SBS as an adhesive was applied in the same manner as described above at a basis weight of 20 g / m ² , and the heating temperature was 100 ° C. These were integrated by heat-sealing with a laminating machine (manufactured by HASHIMA Co., Ltd .: linear adhesive press HP-600LF) to obtain a water-absorbent sheet structure intermediate having a primary liquid-absorbing layer.

Similarly to the above, on the hot melt coating machine set at a heating temperature of 150 ° C., the intermediate body of the water absorbent sheet is laid so that the nonwoven fabric B side is the upper part, and the basis weight of the SBS is 5 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin E obtained in Production Example 5 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin E was uniformly laminated on the non-woven fabric B of the intermediate body of the water-absorbing sheet with a basis weight of 50 g / m ² by operating the spray roller and the lower conveyor.

A laminate obtained by sandwiching the obtained laminate with another nonwoven fabric A coated with SBS in the same manner as described above at a basis weight of 5 g / m ² from the top, and then setting the heating temperature to 100 ° C. in the same manner as described above. These were integrated by heat fusion with a machine to obtain a water-absorbent sheet structure having an adsorption layer.

The obtained water absorbent sheet structure was cut into a predetermined size, and the various measurements and evaluations were performed with the absorbent layer (primary liquid absorbent layer) using the water absorbent resin A facing upward. The results are shown in Tables 3 and 4.

(Comparative Example 2)
A non-woven fabric A having a width of 30 cm was laid on a hot melt coating machine (Harry's Co., Ltd .: Marshall 150) set at a heating temperature of 150 ° C., and then SBS (softening point 85 ° C.) as an adhesive was 10 g / weight. It was coated onto the nonwoven m ^2.

Next, silica gel was charged as an adsorbent into the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C). On the other hand, the adhesive-coated non-woven fabric was laid on a conveyor below the spreader. Subsequently, the silica gel was uniformly laminated on the nonwoven fabric at a basis weight of 100 g / m ² by operating the spreading roller and the lower conveyor. In this way, an adsorption layer composed of silica gel and an adhesive was formed.

The obtained laminate was sandwiched between nonwoven fabrics B as an air-permeable fraction layer in which the SBS as an adhesive was applied in the same manner as described above at a basis weight of 10 g / m ² , and the heating temperature was 100 ° C. These were integrated by heat fusion using a laminating machine (manufactured by HASHIMA Co., Ltd .: linear adhesive press HP-600LF) to obtain a water absorbent sheet structure intermediate having an adsorption layer.

In the same manner as described above, a water absorbent sheet constituting intermediate is laid on a hot melt coater set at a heating temperature of 150 ° C. so that the nonwoven fabric B side is at the top, and the basis weight of SBS is 20 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin A obtained in Production Example 1 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin A was uniformly laminated on the non-woven fabric B of the intermediate body of the water-absorbent sheet structure with a basis weight of 200 g / m ² by operating the spreading roller and the lower conveyor.

Laminate obtained by sandwiching the obtained laminate with another non-woven fabric B coated with SBS in the same manner as described above at a weight per unit area of 20 g / m ² , and then setting the heating temperature to 100 ° C. as described above These were integrated by heat fusion with a machine to obtain a water absorbent sheet constituting intermediate having a primary liquid absorption layer.

Similarly to the above, on the hot melt coating machine set at a heating temperature of 150 ° C., the intermediate body of the water absorbent sheet is laid so that the nonwoven fabric B side is the upper part, and the basis weight of the SBS is 5 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin E obtained in Production Example 5 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin E was uniformly laminated on the non-woven fabric B of the intermediate body of the water-absorbing sheet with a basis weight of 50 g / m ² by operating the spray roller and the lower conveyor.

A laminate obtained by sandwiching the obtained laminate with another nonwoven fabric A coated with SBS in the same manner as described above at a basis weight of 5 g / m ² from the top, and then setting the heating temperature to 100 ° C. in the same manner as described above. These were integrated by heat fusion with a machine to obtain a water-absorbent sheet structure having a secondary liquid-absorbing layer.

The obtained water absorbent sheet structure was cut into a predetermined size, and the above various measurements and evaluations were performed so that the adsorption layer using silica gel was on the upper side. The results are shown in Tables 3 and 4.

(Comparative Example 3)
A non-woven fabric A having a width of 30 cm was laid on a hot melt coating machine (Harrys Co., Ltd .: Marshall 150) set at a heating temperature of 150 ° C., and then SBS (softening point 85 ° C.) as an adhesive was 20 g / weight. It was coated onto the nonwoven m ^2.

Next, water-absorbing resin A was charged as a water-absorbing resin at the inlet of a roller-type spreader (manufactured by HASHIMA CORPORATION: Sinter Ace M / C). On the other hand, the adhesive-coated non-woven fabric was laid on a conveyor below the spreader. Subsequently, the water-absorbing resin A was uniformly laminated on the nonwoven fabric at a basis weight of 200 g / m ² by operating the spraying roller and the lower conveyor.

The obtained laminate was sandwiched between nonwoven fabrics B as an air-permeable fraction layer in which the SBS as an adhesive was applied in the same manner as described above at a basis weight of 20 g / m ² , and the heating temperature was 100 ° C. These were integrated by heat-sealing with a laminating machine (manufactured by HASHIMA Co., Ltd .: linear adhesive press HP-600LF) to obtain a water-absorbent sheet structure intermediate having a primary liquid-absorbing layer.

Similarly to the above, on the hot melt coating machine set at a heating temperature of 150 ° C., a water absorbent sheet constituting intermediate is laid so that the non-woven fabric B side is at the top, and the basis weight of SBS is 10 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, activated carbon was charged as an adsorbent into the inlet of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Then, the activated carbon was uniformly laminated | stacked on the nonwoven fabric B of the said water-absorbing sheet structure intermediate body with a fabric weight of 100 g / m < ² > by operating a spreading | diffusion roller and a lower conveyor. In this way, an adsorption layer composed of activated carbon and an adhesive was formed.

Laminate obtained by sandwiching the obtained laminate with another non-woven fabric B coated with SBS in the same manner as described above at a basis weight of 10 g / m ² from the top, and then setting the heating temperature to 100 ° C. as described above These were integrated by heat-sealing with a machine to obtain a water absorbent sheet constituting intermediate having an adsorbing layer.

Similarly to the above, on the hot melt coating machine set at a heating temperature of 150 ° C., the intermediate body of the water absorbent sheet is laid so that the nonwoven fabric B side is the upper part, and the basis weight of the SBS is 5 g / m ² as an adhesive. It applied on the nonwoven fabric B of a water absorbing sheet structure intermediate body.

Next, the water-absorbent resin E obtained in Production Example 5 was charged as a water-absorbent resin into the charging port of the roller-type spreader. On the other hand, a water absorbent sheet constituting intermediate was laid on the conveyor below the spreader with the surface coated with the adhesive facing up. Subsequently, the water-absorbing resin E was uniformly laminated on the non-woven fabric B of the intermediate body of the water-absorbing sheet with a basis weight of 50 g / m ² by operating the spray roller and the lower conveyor.

A laminate obtained by sandwiching the obtained laminate with another nonwoven fabric A coated with SBS in the same manner as described above at a basis weight of 5 g / m ² from the top, and then setting the heating temperature to 100 ° C. in the same manner as described above. These were integrated by heat fusion with a machine to obtain a water-absorbent sheet structure having a secondary liquid-absorbing layer.

The obtained water absorbent sheet structure was cut into a predetermined size, and the above various measurements and evaluations were performed with the absorbent layer (primary liquid absorbent layer) using the water absorbent resin A facing upward. The results are shown in Tables 3 and 4.

(Comparative Example 4)
In Example 1, a water-absorbent sheet structure was obtained by the same method as in Example 1 except that the water-absorbing resins A and E and the adsorbent were sprayed without using SBS as an adhesive.

(Comparative Example 5)
In Example 1, the water absorbing resin A as the water absorbing resin used for the primary liquid absorbing layer was changed to the water absorbing resin D obtained in Production Example 4, and the water absorption was performed in the same manner as in Example 1. A sheet structure was obtained.

(Comparative Example 6)
In Example 1, the water absorbing resin A as the water absorbing resin used in the primary liquid absorbing layer was changed to the water absorbing resin C obtained in Production Example 3, and the water absorption was performed in the same manner as in Example 1. A sheet structure was obtained.

(Comparative Example 7)
In Example 1, the water absorbing resin E as the water absorbing resin used for the secondary liquid absorbing layer was changed to the water absorbing resin D obtained in Production Example 4, and water absorption was performed in the same manner as in Example 1. A sheet structure was obtained.

  The water absorbent sheet structures obtained in Comparative Examples 4 to 7 were cut into a predetermined size, and the various measurements and evaluations were performed so that the primary liquid absorbent layer was on the upper side. The results are shown in Tables 3 and 4.

  From Table 2 to Table 4, as in Examples 1 to 6, use a water absorbent resin within the scope of the present invention for the primary liquid absorption layer and the secondary liquid absorption layer, and provide an adsorption layer at a specific location. Thus, it can be seen that it has excellent performance in the amount of return, the leak index in the slope, and the odor sensory test.

  On the other hand, regarding the comparative example, when the adsorption layer is not present (Comparative Example 1), when the adsorption layer is provided between the nonwoven fabric and the primary liquid absorption layer (Comparative Example 2), the adsorption layer is the primary absorption. In the case of being provided between the liquid layer and the secondary liquid absorption layer (Comparative Example 3), the effect of suppressing odor was low in the odor sensory test. When no adhesive is used in the absorbent layer (Comparative Example 4), the shape stability of the water absorbent sheet structure is poor, and in the leak test particularly in the slope, a large amount of water absorbent resin spills out when the test solution is introduced, and the water absorbent sheet The shape of the structure collapsed. When the water absorption rate of the water-absorbing resin in the primary liquid-absorbing layer is less than 25 seconds (Comparative Example 5), the gel blocking phenomenon of the water-absorbing resin can be seen by adding the test solution, and the leakage index at the total penetration rate or slope Etc. were low. In the case where the water absorption rate of the water absorbent resin of the primary liquid absorption layer exceeds 80 seconds (Comparative Example 6) and the water absorption rate of the secondary liquid absorption layer exceeds 15 seconds (Comparative Example 7), Since the absorption of the test solution was slow, the evaluation of the leakage index in the slope was low.

  The water-absorbent sheet structure according to the present invention can be used for absorbent articles in the sanitary material field, agricultural field, building material field, and the like, and in particular, can be suitably used for absorbent articles in the sanitary material field.

DESCRIPTION OF SYMBOLS 10 Water-absorbing sheet structure 11 Adhesive 12 Water-absorbing resin 13 Primary liquid-absorbing layer 14 Water-absorbing resin 15 Secondary liquid-absorbing layer 16 Adsorbent 17 Adsorbing layer 18 Non-woven fabric 19 Non-woven fabric 20 Adhesive 21 Breathable fraction layer 31 Mounting base 32 Acrylic plate 33 Absorbent article 34 Drip funnel 35 Balance 36 Tray

Claims (7)

The absorbent layer comprising a water absorbent resin, an adsorbent and an adhesive is a water absorbent sheet structure having a structure sandwiched from above and below the absorbent layer by a nonwoven fabric,
The absorption layer has a structure divided into 1) a primary liquid absorption layer, 2) a secondary liquid absorption layer, and 3) an adsorption layer containing an adsorbent, wherein the adsorption layer includes a secondary liquid absorption layer and Having a structure that exists between the nonwovens,
(1) The physiological saline water absorption speed of the water absorbent resin used in the primary liquid absorbent layer is 25 to 80 seconds, and (2) The physiological saline water absorption speed of the water absorbent resin used in the secondary liquid absorbent layer is 1-15 seconds,
Absorbent sheet construction.   The water absorbent sheet structure according to claim 1, wherein the adsorbent is at least one selected from the group consisting of activated carbon, silica gel, zeolite, alumina, bentonite, diatomaceous earth, and bauxite. The water-absorbing resin content is 100 to 1000 g / m ² and the adhesive content is 0.05 to 2.0 times the total (mass basis) of the water-absorbing resin and adsorbent content. The water absorbent sheet structure according to claim 1 or 2.   The water absorbent sheet structure according to any one of claims 1 to 3, wherein the nonwoven fabric is a nonwoven fabric containing at least one selected from the group consisting of rayon fibers, polyolefin fibers, and polyester fibers.   The adhesive is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer adhesive, a styrene elastomer adhesive, a polyolefin adhesive, and a polyester adhesive. The water absorbent sheet structure according to Item. The water-absorbent sheet structure according to any one of claims 1 to 5, wherein the following (A) to (C):
(A) The thickness of the water absorbent sheet structure is 5 mm or less,
(B) the total penetration rate is 120 seconds or less, and (C) the leak index at the slope is 100 or less,
Water-absorbent sheet structure that satisfies all of the properties of   An absorptive article formed by sandwiching the water absorbent sheet structure according to any one of claims 1 to 6 between a liquid permeable sheet and a liquid impermeable sheet.

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