JP2018174987A - Absorbent structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent structure capable of easily recycling an absorbent article. An absorption structure contains a material soluble in water above 50 ° C. and is used for absorption of a liquid containing water as a component. It is preferable that the material is a polysaccharide and does not contain a water-insoluble polymer absorber. It is also preferable that the material contains two or more different polysaccharides. It is also preferable that the absorption structure is a porous body. It can also be used in the form of an absorbent article incorporating an absorbent structure. [Selection diagram] None

Description

  The present invention relates to an absorbent structure and an absorbent article provided with the same. The present invention also relates to a method of recycling components of an absorbent article.

  BACKGROUND ART Absorbent articles such as disposable diapers and sanitary napkins are configured by bonding their constituent members using an adhesive such as a hot melt adhesive. By the way, in view of recent environmental problems, recyclability is required for all products. The same applies to absorbent articles. However, since a strong adhesive such as the above-described hot melt adhesive is used for the absorbent article, it is not easy to decompose the article into individual members for recycling.

  As a conventional technique regarding recycling of absorbent articles, for example, Patent Document 1 proposes absorbent products that can be easily reprocessed. The absorbent product is composed of durable material partially recyclable by washing, and the remaining part is composed of disposable material that is treated and discarded in a single use. The components of the durable material and the components of the disposable material are reduced by the temperature-sensitive binder so that they can retain the integrated state while containing excrement after use, and in the integrated state after use. It is bound to be separated by immersion in an aqueous medium which is in a state of warming enough to obtain fungal action.

  Patent Document 2 proposes a method for efficiently recovering low ash pulp fibers from a used sanitary product containing pulp fibers and a polymer absorbent. The method comprises the steps of treating a used sanitary product with an ozone-containing gas to decompose and remove at least a part of the polymer absorbent in the used sanitary product, and a used sanitary product treated with the ozone-containing gas, Disassembling the used hygiene products into components by stirring in an aqueous solution containing a disinfectant or in water.

Unexamined-Japanese-Patent No. 2003-135519 JP, 2016-064325, A

  In the absorbent article, the absorbent contains an absorbent polymer which is a material intended to absorb and hold a liquid. Since the absorbent polymer has a property of swelling by absorbing and holding water, it is necessary to dry the absorbent polymer in order to recycle a used absorbent article. However, there is a disadvantage that a large amount of energy is required to dry the water-absorbing absorbent polymer. In the above-mentioned patent documents 2, the process of drying an absorptive polymer is omitted by carrying out the oxidation decomposition by carrying out ozonization of the absorptive polymer which absorbed and held water. In addition to being uneconomical, attention must be paid to the environmental load and ecological safety of the decomposition products of other materials, as the oxidative decomposition by ozone requires long-term treatment. In addition, ozone is a substance that must be handled with care, so it can not be said to be a substance that can be easily used in recycling facilities.

  Therefore, an object of the present invention is to provide an absorbent material that is easy to recycle.

  The present invention provides an absorbent structure that contains a water-soluble material that exceeds 50 ° C. and that is used to absorb a liquid that contains water as a component.

  The present invention also provides an absorbent article provided with the above-mentioned absorbent structure.

  Furthermore, the present invention places the absorbent article in water exceeding 50 ° C. to separate the components of the absorbent article, heats or melts the meltable resin member produced by the separation, and then reuses it. Provided is a method of recycling components of an absorbent article.

  According to the present invention, the absorbent article can be easily recycled.

  The present invention will be described below based on its preferred embodiments. The absorbent structure of the present invention is a solid having a certain form. In addition, the absorbent structure of the present invention is non-powdery and has a certain outer shape. Specifically, the absorbent structure of the present invention has an appearance such as, for example, a plate-like body, a massive body, a fibrous body, a sheet-like shape, a strand-like shape and the like. As apparent from the preferred method of manufacturing the absorbent structure described later, the absorbent structure can be formed into various shapes by methods such as extrusion molding and mold molding. That is, the absorbent structure of the present invention has free formability and has a high degree of freedom in forming. Therefore, it is possible to easily obtain a laminated body in which a plurality of absorbing structures having complicated three-dimensional shapes are laminated, or an integrally formed body in which each member constituting the laminated body is integrated with each other. When the absorbent structure of the present invention is a plate, at least one of the main surfaces of the pair of main surfaces of the plate may have a concavo-convex structure. As an example of this concavo-convex structure, a block structure etc. which consist of a crevice which consists of a slot which intersects perpendicularly in all directions, and a convex part of a plane view rectangle shape surrounded by the slot are mentioned.

  The absorbent structure of the present invention consisting of a solid substance may be a solid structure or may have a porous structure. From the viewpoint of ensuring absorption and retention of the liquid containing water as a component, the absorbent structure of the present invention preferably has a porous structure.

  When the absorbent structure of the present invention has a porous structure, when the absorbent structure is, for example, a plate or a lump, the plate or the lump itself has a porous structure. Is preferred. On the other hand, when the absorbent structure of the present invention is a fibrous body, the fibrous body itself has a porous structure, or the fibrous body itself does not have a porous structure, but a plurality of the fibers It is preferable that the bodies are intertwined to form a network structure, and a part of the network in the network structure forms a porous structure.

  When the absorbent structure of the present invention has a porous body structure, the structure of the porous body may be an open cell type or a part of a closed cell type It is also good. When the absorbent structure of the present invention is produced, for example, by the lyophilization method described later, an open-cell type porous structure absorbent structure is obtained. The size of the pores in the porous structure (median diameter determined by the measurement method described later) is preferably 20 μm or more in at least a part of the absorbent structure from the viewpoint of efficiently performing absorption and retention of water, More preferably, it is 30 μm or more, and more preferably 50 μm or more. The thickness is preferably 500 μm or less, more preferably 400 μm or less, and still more preferably 300 μm or less. The size of these pores may be different in each part of the absorbent structure, for example, in the front and back, in the middle and in the end, and / or in the longitudinal front and rear of the absorbent structure. The size of the pores may be varied.

  By setting the pore size to the above-mentioned lower limit value or more, it is possible to achieve excrement containing solid contents such as menstrual blood, cormorants, watery feces etc. and water without clogging the solid contents. It can absorb well. In addition, by setting the pore size to the above-mentioned upper limit value or less, the contact efficiency between the low viscosity liquid such as urine and sweat and the surface of the polysaccharide is improved, and the liquid can be efficiently immobilized.

  The size of the pores can be measured using a mercury porosimeter, Autopore IV 9500 series (manufactured by Shimadzu Corporation), in accordance with the mercury intrusion method (JIS R 1655).

  The mercury porosimetry is a method for obtaining information on the physical shape of the absorbent structure by measuring the size and volume of the pores of the porous structure. The principle of the mercury intrusion method is to apply pressure to mercury and inject it into the pores of the object to be measured, and measure the relationship between the pressure applied at that time and the injected mercury volume. Hereinafter, a method of measuring the pore size distribution of the absorbent structure using a mercury porosimeter will be described. The description describes an absorbent article such as a diaper or a sanitary napkin as an example. In addition, "pore diameter" is synonymous with "size of pore".

[Method of Measuring Pore Size Distribution of Absorbent Structure]
First, the absorbent structure is taken out of the absorbent article (product including the absorbent structure). At this time, it is important to take out without destroying the structure of the absorbent structure. Generally, a hot melt pressure sensitive adhesive is used for assembling the absorbent article, so it is preferable to take it out after the absorbent structure is cooled. As a cooling method, for example, by spraying a suitable amount of cold spray (for example, Nichiban Co., Ltd. sport cooling spray, CS480), it becomes possible to take out without destroying the structure of the absorbent structure. Alternatively, means may be used such as sufficient cooling of the entire absorbent article in liquid nitrogen, or the like, or the like may be devised in accordance with the property of the absorbent article to be analyzed. This means is common to the other measurements in the present specification.

  Next, the taken out absorbent structure is cut into 5 mm × 10 mm × 3 mm. The cut samples are set in a sample cell of a mercury porosimeter (manufactured by Shimadzu Corporation), and the pore size distribution of 1 to 600 μm is measured. Based on the obtained pore distribution curve (differential / integral curve), the 50% median diameter is taken as the measured value of the pore diameter of the absorbent structure. The measurement is performed at five points, and the average value of the three points excluding the maximum and minimum measurement values is taken as the measurement value. The size of the absorbent structure to be subjected to the measurement can be appropriately adjusted according to the amount of pores and the distribution of the absorbent structure.

  The absorbent structure of the present invention is used to absorb a liquid containing water as a component. The liquid containing water as a component refers to various liquids containing water as a component having fluidity at the temperature of use of the absorbent structure of the present invention in addition to water itself. Fluidity is the property of having a constant volume but no inherent profile. The liquid containing water as a component may be a natural product or a synthetic product. Natural products include those produced in the natural world as well as those produced or excreted from a living body. Urine, menstrual blood, feces (so-called watery feces containing a large amount of water, soft feces, diarrhea feces etc.), stools, sweat, exudates from wounds, breast milk, meat are produced or excreted from the living body And drips from fish fillets.

  The term "absorption" in the present invention includes not only uptake into the interior of the absorbent structure but also substantial migration of the liquid by permeation or diffusion into the pores possessed by the absorbent structure. The difficulty in moving refers to a state in which the liquid does not move even when an external force is applied under the use conditions of the absorbing structure. For example, it means that the liquid is held by thickening, gelation, or the interaction between a part of the absorbent structure and water. Due to the difficulty in moving the liquid, movement of the liquid is less likely to occur even when an external force such as tilting of the absorbent structure acts, and leakage of the liquid can be suppressed.

  One part by weight of the absorbent structure was dissolved in 100 parts by weight of deionized water as an indicator that the liquid was substantially difficult to move (that is, the concentration of the absorbent structure in deionized water was 1% by weight) ) It is preferable to measure the thickening property (hereinafter also referred to as 1% deionized water thickening property). From the viewpoint of preventing leakage of the liquid from the absorption structure, the 1% deionized water thickening property in the present invention is preferably 0.1 Pa · s or more, more preferably 1 Pa · s or more, and 4 Pa · More preferably, it is s or more, further preferably 10 Pa · s or more. In particular, when the 1% deionized water thickening property is 4 Pa · s or more, even if an external force such as tilting of the absorbing structure acts, the liquid leaks due to the fact that the liquid substantially moves. It can be effectively suppressed. The 1% deionized water thickening can be measured according to the method described in the examples below.

  When the absorbent structure of the present invention is a porous body, the absorbent structure has the property of being capable of retaining water in the pores of the porous body. This property is due to the action on the water of the material constituting the absorbent structure. Specific examples of this action on water include phenomena such as hydration, swelling, thickening and gelation. Therefore, the absorbent structure of the present invention does not show an extreme volume increase even after absorbing and holding water. In contrast to this property, the cross-linked polyacrylate which is widely used for absorption and retention of water absorbs and retains water by ion osmotic pressure, and exhibits a large volume increase by absorption and retention of water.

  The absorbent structure of the present invention comprises a material soluble in water at above 50 ° C. In the following description, water of more than 50 ° C. is conveniently referred to as “hot water”. Since the absorbent structure of the present invention is configured to include such a material, the absorbent structure dissolves in the hot water by bringing it into contact with the hot water. Therefore, for example, by bringing the absorbent article provided with the absorbent structure of the present invention into contact with hot water, the members other than the absorbent structure can be separated from the absorbent article.

  “Soluble in water exceeding 50 ° C.” means that 1.00 g of the absorbent structure of the present invention is precisely weighed, placed in a beaker containing 200 g of deionized water at 50 ° C., 300 rpm using a stirrer and a propeller. The temperature is gradually raised while stirring, and the temperature at which the dissolution starts is visually observed, and when heated at the dissolution start temperature for 60 minutes, it becomes a uniform liquid with a sense of transparency. The temperature of the beaker contents is raised by disposing the beaker in a water bath. Here, even if the temperature of the beaker contents exceeds 90 ° C., if there is white turbidity or undissolved matter, filter with a Buchner funnel type glass filter and confirm that the polymer absorbent is not contained by the method described later .

The absorbent structure of the present invention is preferably configured to include the above-described soluble material. Such materials include, for example, polysaccharides. Polysaccharide is a general term for substances in which many monosaccharide molecules are polymerized by glycosidic bond. Examples of polysaccharides include acidic polysaccharides derived from anionic groups such as carboxyl groups, basic polysaccharides, nonionic polysaccharides, and amphoteric polysaccharides. In the present invention, one or more of these polysaccharides can be used without particular limitation as long as they have the above-mentioned solubility. The material preferably contains two or more different polysaccharides, in order to facilitate adjustment of the dissolution temperature in water.
In the present specification, “acidic”, “anionic” and “anionic” are respectively synonymous, and “basic”, “cation” and “cationic” are also the same. Therefore, these expressions can be read appropriately.

  The structure of the polysaccharide is specified according to the type, and the case where a plurality of polysaccharides different in main structure are used in combination or in combination is referred to as "two or more". Moreover, "one" or "alone" means that polysaccharides having different main structures are used without being mixed or not combined. Therefore, it is used in the process of separation and purification of polysaccharides and structural isomers having the same structure and different molecular weight distributions, or monosaccharides, disaccharides and other low molecular weight saccharides (glucose, lactose, dextrin or maltose), the polysaccharides It is acceptable to include isopropanol, which is a type of drug. When the ratio of constituent sugars determined by high-performance liquid chromatography described later contradicts the ratio of constituent sugars estimated from a single polysaccharide, it can be considered that a plurality of polysaccharides are mixed.

  The constituent sugars derived from polysaccharides can be determined as follows. That is, the amount of free sugar is previously determined by high performance liquid chromatography (HPLC) method, and then the sample is acid hydrolyzed, and similarly the amount of free sugar and the composition derived from the polysaccharide are obtained by HPLC method. Calculate the sum with the amount of sugar. By subtracting the amount of free existing sugar determined separately, it is possible to determine the sum of the amounts of constituent sugars derived from polysaccharide.

For high-performance liquid chromatograph measurement, for example, a column for sugar analysis: Shodex SUGARSP 0810 (8.0 mm × 300 mm, Shodex Co., Ltd.), mobile phase: H ₂ O, flow rate: 1.0 mL / min, thermostat temperature: 80 ° C., detection : Shodex RI, injection volume: 10 μL, standard sample of various sugars as internal standard substance (monosaccharide, as disaccharide, fructose, rhamnose, glucose, sucrose, sucrose, lactose, lactose, xylose, mannose, rhamnose, arabinose, ribose, Galactose, fucose, etc., manufactured by Wako Pure Chemical Industries, Ltd. can be used.

  As a combination of two or more different polysaccharides, a combination using an acidic polysaccharide as the first polysaccharide and a non-ionic polysaccharide as the second polysaccharide can be mentioned. Moreover, a combination using an anionic polysaccharide as the first polysaccharide and an amphoteric polysaccharide as the second polysaccharide may be mentioned. Furthermore, a combination using a basic polysaccharide as the first polysaccharide and a non-ionic polysaccharide as the second polysaccharide may be mentioned.

  When two or more different types of polysaccharides are used in combination, the material constituting the absorbent structure of the present invention is a first polysaccharide and a second polysaccharide different from the first polysaccharide. Is preferred. When these two types of polysaccharides are used, the material constituting the absorbent structure of the present invention preferably contains 20% by mass or more of the second polysaccharide relative to the first polysaccharide, particularly 30 It is preferable to contain at least 40% by mass, particularly at least 40% by mass. The material constituting the absorbent structure of the present invention preferably contains the second polysaccharide in an amount of 80% by mass or less, particularly 70% by mass or less, particularly 60% by mass or less based on the first polysaccharide. Is preferred. By setting the content of the first polysaccharide within the above-mentioned range, the physical cross-link described later is sufficiently formed, and the thickening effect and the gelation effect by the mixing effect with the second polysaccharide, the compression resistance Water retention performance such as improvement of

The mixing amount of the first polysaccharide and the second polysaccharide can be determined, for example, by the following method.
In order to remove water insolubles from the absorbent structure, 1 part by mass of the weighed sample is placed in 300 parts by mass of 90 ° C. hot water and stirred, and filtration is performed using a glass filter. By separating and analyzing the acid-degraded product of the polysaccharide mixture contained in the obtained filtrate by the high performance liquid chromatography (HPLC) method described above, the constituent sugars in the absorbent structure are detected, and the amount of constituent sugars is estimated. Can.

  The basic skeleton of polysaccharides has been determined by prior research and the literature. As polysaccharides, gellan gum, locust bean gum, guar gum, tara gum will be described below as an example, gellan gum is a repeating unit containing two glucose, one glucuronic acid and one rhamnose as a basic skeleton. Locust bean gum is a macromolecule consisting of repeating units containing five mannoses, one galactose, and four polysaccharides as a basic skeleton, and guar gum is a total of two mannoses and one galactose. It is a polymer consisting of repeating units containing three polysaccharides as a basic skeleton, and tara gum is a polymer consisting of repeating units containing three polysaccharides, one mannose and one galactose, as a basic skeleton.

For example, when mannose and galactose are not detected from the above-mentioned acid degradation product, it can be estimated that the absorption structure to be analyzed is composed of gellan gum alone. In addition, when two glucoses, four mannoses and one galactose are detected from the above-mentioned acid degradation product, it can be estimated that the equivalent amounts of duran gum and locust bean gum are contained. From the above-mentioned acid degradation products, when five mannose and two galactose are detected, it can be estimated that guar gum and cod gum are contained in equal amounts.
Thus, even if the constituent sugars are common, the mixture amount of polysaccharides is estimated by calculation based on the abundance of constituent sugars obtained as a result of analysis, using the fact that the ratio differs depending on polysaccharides. be able to.

  When the acidic polysaccharide to which pyruvic acid is bound is contained, thereafter, pyruvic acid is quantified by the following method, and it is calculated from the ratio of the total amount of sugars to the quantitative value.

  When an acidic polysaccharide is used as the first polysaccharide, the first polysaccharide is preferably an acidic polysaccharide to which pyruvic acid is bound. The absorbent structure of the present invention is characterized in that it contains an acidic polysaccharide to which pyruvic acid, which is one of polysaccharides, is bound, and a polysaccharide other than an acidic polysaccharide to which pyruvic acid is bound. From the viewpoint of enhancing the In the following description, for convenience of explanation, the acid polysaccharide to which pyruvate is bound may be referred to as “polysaccharide A”, and polysaccharides other than the acid polysaccharide to which pyruvate is bound may be referred to as “polysaccharide It may be called "sugar B".

  The detection of an acidic polysaccharide such as an acidic polysaccharide to which pyruvic acid is bound can be monitored by directly dropping Alcian blue staining solution onto a sample and observing with a microscope. If coloring can be confirmed by this operation, it means that an acidic polysaccharide is present.

  Alcian blue staining solution can be prepared as follows. 0.01 g of Alcian Blue 8GX (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in 20 mL of a 50% (v / v) aqueous solution of ethanol, to which hydrochloric acid or sodium dihydrogen phosphate is appropriately added and pH adjusted, It can be filtered with (No. 5B) to obtain 0.05% 50% (v / v) aqueous ethanol solution.

  Alcian blue staining solution is known to bind to both a carboxyl group and a sulfate group at pH 2.5 and to bind only to a sulfate group at pH 1.0, so it develops color at pH 2.5, pH 1.0 In the case where no color is developed, it can be understood that it has a carboxyl group. Moreover, if color development occurs at pH 1.0, it can be understood that it is an acidic polysaccharide having a sulfate group. When the degree of color development is not sufficient due to interference from the coexisting substance or the amount of contained sugar and the observation with the naked eye is difficult, the concentration of ethanol and / or alcyan blue can be appropriately adjusted.

  Examples of acidic polysaccharides to which pyruvic acid is bound include xanthan gum and the like. Whether or not xanthan gum is contained as the pyruvic acid-bound acidic polysaccharide can be confirmed by the presence of pyruvate at the end of xanthan gum. That is, the amount of pyruvic acid obtained is measured after hydrolyzing the acid polysaccharide pyruvate with hydrochloric acid according to the following method.

  A 0.600 g sample is precisely weighed and dissolved in 100 mL deionized water in a beaker while heating in a 90 ° C. water bath. After accurately making up to 100 mL with a volumetric flask, 10 mL of the solution is put into the flask, 20 mL of 1 mol / L hydrochloric acid is added, the mass is precisely weighed, and heated in a 90 ° C. water bath for 4 hours. After cooling, the mass of the flask contents is corrected with deionized water to the mass before heating. Weigh exactly 2 mL of this solution, add exactly 10 mL of a solution of 2,4-dinitrophenylhydrazine in 2 mol / L hydrochloric acid (1 in 200), and shake. After standing for 5 minutes, extract twice with 5 mL of ethyl acetate. Combine the ethyl acetate extracts, extract three times with 5 mL portions of sodium carbonate solution (1 → 10), transfer the extract to a volumetric flask, add sodium carbonate solution (1 → 10) to make exactly 100 mL, Let it be a liquid.

  Separately, 0.360 g of pyruvic acid is taken and water is added to make exactly 100 mL. Pipet 1 mL of this solution, add water to make exactly 100 mL. Accurately measure 2 mL of this solution, add exactly 10 mL of a solution (1 → 200) in which 2,4-dinitrophenylhydrazine is dissolved in 2 mol / L hydrochloric acid, and operate in the same manner as the test solution to obtain a comparison solution. For these solutions, the absorbance at a wavelength of 375 mm is measured using water as a control. The amount of constituent sugar derived from xanthan gum can be calculated by equivalent calculation from the amount of pyruvic acid obtained. The difference between the sum of the amounts of constituent sugars derived from polysaccharides and the amount of constituent sugars derived from xanthan gum determined by the above-mentioned HPLC method can be regarded as the amount of constituent sugars derived from other polysaccharides.

  When the material constituting the absorbent structure of the present invention contains polysaccharide A and polysaccharide B, microscopically, the molecular chain of polysaccharide A and the molecular chain of polysaccharide B physically crosslink each other. It forms a macroscopic structure. Physical crosslinking is a term used in contrast to chemical crosslinking. Physical crosslinks link polymer chains together by relatively weak bonds such as ionic bonds or hydrogen bonds, in contrast to chemical crosslinks, which are crosslinks that link polymer chains together by strong chemical bonds called covalent bonds. Cross-linking mode. When the material constituting the absorbent structure of the present invention has physical crosslinking, it is possible to reversibly change between the gel state and the sol state. The material constituting the absorbent structure of the present invention contains polysaccharide A and polysaccharide B, and due to physical cross-linking between them, in addition to being easily dissolved in hot water, it absorbs cold water. By so doing, it is possible to significantly thicken and retain cold water.

  The physical crosslinking according to the present invention can be considered as follows. Here, xanthan gum will be described as an example of one of pyruvic acid-bound acidic polysaccharides. In xanthan gum, at an operating temperature of the absorbent structure of the present invention, for example, around body temperature, a part of molecular chains of xanthan gum takes a helical structure in an aqueous solution. The helical structure portion and the smooth portion (the portion with a small amount of galactose residues) of the main chain of polysaccharide B are associated by hydrogen bonding to form a crosslinked region. Alternatively, part of the helical structure is disrupted to produce a structure in which the molecular chain of polysaccharide B is sandwiched or an entangled structure. The interaction between the helical structure site of these xanthan gums and other polysaccharides results in a state in which the movement of the molecular chains of each other is partially restricted.

  In a solution of xanthan gum alone, the coil-helix transition temperature is determined by DSC measurement and appears around 50 ° C. However, when an interaction occurs due to mixing with other polysaccharides, a shift of the exothermic peak occurs. Therefore, the interaction between polysaccharides can be monitored also by the exothermic peak shift of DSC. However, since the shift of the exothermic peak is also caused by the addition of the salt to the aqueous solution of xanthan gum, the presence of the salt in the absorbent structure is separately confirmed by a method such as conductivity measurement.

  The state in which the molecular chain is partially constrained, that is, physical crosslinking, increases the thickening and gelling effects when an interaction with water occurs, as compared with those in which a polysaccharide is used alone. Also, an improvement in the compressive strength of the obtained gel is observed. Furthermore, unlike chemical crosslinking in an acrylic acid-based crosslinked product, heating weakens the interaction of molecular chains with each other to cause reversible sol-gel transition and dissolution.

  Xanthan gum, which is a kind of polysaccharide A contained in the absorbent structure of the present invention, is composed of repeating units containing, as basic skeletons, a total of five polysaccharides of two glucose, two mannose and one glucuronic acid as shown below It is a polymer. The main chain of xanthan gum is the β-1,4 bond of D-glucose, and this bond has the same bonding mode as cellulose. The side chain contains one glucuronic acid between the two mannoses. The side chains are located at every other glucose and are attached to the 3-position of glucose. A part of D-mannose at the side of the side chain end has ketal bond with pyruvate at the 4- and 6-positions. The terminal D-mannose is acetylated at the 6-position.

  The xanthan gum used in the present invention is not particularly limited in its molecular weight as long as the absorbent structure can absorb and retain the liquid. The general weight average molecular weight of available xanthan gum is 100,000 or more and 50 million or less.

  In contrast to polysaccharide B contained in the absorbent structure of the present invention, the acidic polysaccharide to which pyruvic acid as polysaccharide A described above is bound is an acidic polysaccharide derived from a carboxyl group, for example, non-ionic It is preferable that the polysaccharides are amphoteric polysaccharides or amphoteric polysaccharides from the viewpoint that separation of polysaccharide A and polysaccharide B does not occur easily and heterogeneous gelation of polysaccharide A and polysaccharide B does not easily occur. However, use of an acidic polysaccharide other than xanthan gum as the polysaccharide B is not hindered. Polysaccharide B can be used individually by 1 type or in combination of 2 or more types.

  When an acidic polysaccharide to which pyruvic acid, which is a type of polyanionic polysaccharide, is mixed in an aqueous solution, from the viewpoint of suppressing formation of polyion complex and aggregation due to electrostatic interaction, polysaccharide B is a non-ionic system It is preferable to use the following polysaccharides or amphoteric polysaccharides. By suppressing the aggregation, the structure of the absorbent structure becomes uniform, mechanical strength can be secured in both the dry and wet cases, and the structure of the absorbent structure can be maintained during use. In addition, as described above, the absorbent structure of the present invention makes it difficult to move the liquid due to the affinity with water of the material, so that the liquid retention of the absorbent structure can be achieved by maintaining the structure of the absorbent structure. You can keep

  Specific examples of the polysaccharide B used in the present invention include locust bean gum which is a non-ionic polysaccharide, guar gum, tara gum, galactomannan, tamarind seed gum, starches (corn starch, corn grits, corn flour, wheat starch ( Wheat flour), rice starch (rice flour), potato starch, sweet potato starch, tapioca starch, sorghum starch, or chemically treated ones or chemically modified modified starch etc. However, starch cross-linked starches are acid polysaccharides And may be used as the first polysaccharide) and the like. Further, specific examples of the polysaccharide B include cationized xanthan gum which is amphoteric polysaccharide, cationized gellan gum, cationized pectin, cationized carrageenan, cationized karaya gum and the like.

  When a non-ionic polysaccharide is used as the polysaccharide B, the separation of the polysaccharide A and the polysaccharide B is less likely to occur by using one having a structure containing three or more mannoses in the repeating unit skeleton, Moreover, it is preferable from the point which heterogeneous gelatinization with polysaccharide A and polysaccharide B becomes difficult to occur. Examples of polysaccharides having such a structure include locust bean gum, cod gum and the like. For example, locust bean gum has a structure having mannose and galactose in a repeating ratio of 4: 1 in the repeating unit as shown below. In addition, tara gum has a structure having mannose and galactose in a unit ratio of 3: 1.

  In the absorption structure of the present invention, the helical structure portion of polysaccharide A, which is an acidic polysaccharide to which pyruvic acid is bound, and the smooth portion (the portion having few galactose residues) of the main chain of polysaccharide B associate by hydrogen bonding. It is preferable to form a physically crosslinked region. This low galactose residue refers to, in other words, mannose in the repeating unit skeleton. Due to the large number of mannose residues, the interaction site with the helical structure of the pyruvate-bound acidic polysaccharide increases, and the repulsion of galactose residues is suppressed to facilitate interaction, which is desirable. Performance is likely to be expressed.

  In the absorbent structure of the present invention, it is preferable from the viewpoint of enhancing the recyclability that the material constituting the absorbent structure contains a polysaccharide and does not contain a water-insoluble polymer absorbent. The water-insoluble polymer absorbent is a material that can absorb and hold water to form a hydrogel, and has low water solubility. The term "water-insoluble" as used herein means that when 0.50 g of the polymer absorbent is placed in 500 g of deionized water maintained at 90 ° C., it is filtered with a Buchner-Rotte type glass filter, which has been weighed beforehand after drying, and the filtrate is The dry residue of the polymer is 10% or less of the initial mass of the polymer absorbent. As a polymer absorber capable of absorbing and holding water to form a hydrogel, for example, a crosslinked product of a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid, polyacrylic acid and salts thereof, and polyacrylate graft thereof Cross-linked polymer, cross-linked vinyl alcohol-acrylate copolymer, cross-linked maleic anhydride grafted polyvinyl alcohol, cross-linked isobutylene-maleic anhydride copolymer, vinyl acetate-acrylic ester copolymer Ken And substances derived from high-molecular polymers that are resistant to decomposition when released to the external environment.

  The absorbent structure of the present invention may contain other components for the purpose of enhancing various performances of the absorbent structure, in addition to the material of which the absorbent structure is comprised of a polysaccharide.

  In order to compensate for the strength of the absorbent structure of the present invention, other fibrous materials such as pulp, semi-synthetic fibers or synthetic fibers can be mixed with the absorbent structure. As pulp, softwood bleached kraft pulp (hereinafter referred to as NBKP), hardwood bleached kraft pulp (hereinafter referred to as LBKP), wood pulp such as used paper pulp, etc. bulked chemically treated pulp such as mercerized pulp and crosslinked pulp, cotton Is preferred. The various fibers can be used singly or in combination of two or more. As the semi-synthetic fiber, rayon, lyocell and tencel are preferable. Further, as the synthetic fibers, polyolefin fibers (polyethylene, polypropylene, polyethylene terephthalate etc.), polylactic acid fibers, polyvinyl alcohol fibers etc. are preferable. When mixing synthetic fibers, it is more preferable to mix polyolefin fibers derived from biomass, polylactic acid fibers, and biodegradable fibers. The various fibers can be used singly or in combination of two or more.

  The absorbent structure is formed of a polysaccharide as a skeleton, but in the case of mixing a polyolefin fiber or a polylactic acid fiber which is a synthetic fiber, a fiber aggregate having such a fiber as a skeleton, for example, a nonwoven fabric, etc. The polysaccharide may be applied or impregnated. The fiber diameter of the synthetic fiber preferably includes a fiber of 4 dtex or more and 30 dtex or less (hereinafter, also referred to as a thick fiber) from the viewpoint of mixing with the polysaccharide. In order to obtain the strength of the fiber assembly, fibers of 1.5 dtex or more and 4 detx or less (hereinafter also referred to as thin fibers) containing a resin modified to have a low melting point may be mixed. The mixing ratio of thick fiber to thin fiber is preferably thick fiber (% by mass) / thin fiber (% by mass) = 90/10 to 50/50. Favorable strength can be acquired as the mixing ratio of a thin fiber is 10 mass% or more, the pore diameter of a fiber assembly becomes large as it is 50 mass% or less, and liquid can be absorbed efficiently. On the other hand, when the mixing ratio of the thin fibers is less than 10% by mass, the strength is not expressed, and when it exceeds 50% by mass, the pore size of the fiber assembly becomes small and efficient liquid absorption can not be performed.

  Various surfactants can be added to the absorbent structure for the purpose of liquid permeability to the absorbent structure, mixing properties of polysaccharides, particle dispersibility, viscosity reduction in extrusion foaming, and the like. The surfactant includes, for example, surfactants such as anionic surfactants, cationic surfactants, and nonionic surfactants, and more preferably nonionic surfactants. Specific examples thereof include higher alcohols and fatty acid sorbitan esters (any of mono, di and tri esters), alkyl glucosides, polyglycerin fatty acid esters, sucrose fatty acid esters and the like. The surfactant may be used alone or in combination of two or more.

  An equilibrium moisture regulator can be added to the absorbent structure to improve the flexibility of the absorbent structure. As the equilibrium moisture regulator, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, polyoxypropylene, trimethylolpropane, pentaerythritol, 1,3-propanediol, 1 And polyols such as 3-butylene glycol and sorbitol.

Since the dissolution of polysaccharide, gelling temperature, gel strength and the like are affected by the amount of metal ion contained in the system, a metal ion scavenger may be contained as appropriate.
Examples of the metal ion scavenger include tetrasodium ethylenediaminetetraacetic acid (EDTA), ethylenediamine-N, N'-disuccinic acid (EDDS), trisodium nitrilotriacetic acid (NTA), pentasodium diethylenetriaminepentaacetic acid (DTPA), hydroxy Aminocarboxylate metal ion scavengers such as ethyl ethylenediaminetriacetic acid (HEDTA) trisodium, L-glutamic acid diacetic acid (GLDA) tetrasodium, 3-hydroxy-2,2'-iminodisuccinic acid tetrasodium (HIDS); hydroxy Phosphate-based metal ion scavengers such as ethylidene diphosphonic acid (HEDP) tetrasodium; polymerized phosphate-based metal ion scavengers such as sodium tripolyphosphate (STPP), sodium pyrophosphate (TSPP), sodium hexametaphosphate; Builders for polymeric detergents such as sodium acrylate and acrylic acid / maleic acid copolymer; Other organic metal ion scavengers such as trisodium citrate and ammonium citrate; Zeolite (crystalline aluminosilicate), sodium silicate etc. An inorganic type metal ion trapping agent etc. are mentioned, These 1 type can be used individually or in mixture of 2 or more types. Among these, ethylenediaminetetraacetic acid (EDTA) tetrasodium, trisodium citrate, sodium tripolyphosphate, sodium acrylate and zeolite are preferred, and trisodium citrate and ethylenediamine-N, N'-disuccinic acid (EDDS), in particular, are preferred. -Hydroxy-2,2'-iminodisuccinic acid tetrasodium (HIDS) is preferable at the point with small environmental impact. These components can be used individually by 1 type or in combination of 2 or more types.

When the absorbent structure of the present invention contains other components in addition to the polysaccharide, the ratio of the polysaccharide to the absorbent structure is preferably 5% by mass or more, and 10% by mass or more. Is more preferable, and 20% by mass or more is more preferable.
The proportion of polysaccharides in the absorbent structure of the present invention can be appropriately adjusted depending on the required absorption performance and other physical properties.

  The absorbent structure of the present invention can be manufactured in various ways. For example, in the case where the absorbent structure contains one or more polysaccharides, and is a plate-like body or a lump, an absorbent structure having a porous structure by subjecting an aqueous solution containing polysaccharides to a lyophilization method You can get the body. Alternatively, an absorbent structure having a porous structure can be obtained by a foam molding method. In the case of using a lyophilization method, a hydrogel containing one or more polysaccharides is frozen to a predetermined shape, and then vacuum dried to sublime water, thereby absorbing the absorption structure of the target shape. Is obtained. For example, in the case of obtaining a plate-like absorbent structure, a hydrogel containing one or more polysaccharides may be placed in a container having a predetermined shape and frozen, and the frozen body may be vacuum dried. In the case of obtaining an absorbent structure comprising a fibrous body, a hydrogel containing one or more polysaccharides is extruded from a die to form a filament, and after freezing the filament as required, a vacuum is applied. It may be dried.

  In this case, in extrusion foam molding using an extruder or the like, absorbent structures having various cross-sectional shapes can be obtained by combining profile extrusion such as changing the shape of a die.

  Below, an example of the conditions of extrusion molding by an extruder is demonstrated. However, the conditions for extrusion molding are not limited to the following, and appropriate conditions can be set in consideration of the extrusion molding apparatus to be used, the type or amount of material, the shape of the desired composition, and the like.

  The feed screw speed of the extruder is preferably 100 rpm or more, more preferably 130 rpm or more, and preferably 150 rpm or less. The rotation speed of the main screw is preferably 150 rpm or more, more preferably 180 rpm or more, and preferably 230 rpm or less, more preferably 220 rpm or less. When the barrel temperature of the extruder is controlled in four temperature ranges, when the barrel temperature is 1, the barrel temperature 2, the barrel temperature 3, and the barrel temperature 4 from the upstream toward the downstream, the barrel temperature 1 Is preferably 60 ° C. or more, more preferably 70 ° C. or more, and preferably 100 ° C. or less, more preferably 90 ° C. or less. The barrel temperature 2 is preferably 110 ° C. or more, more preferably 120 ° C. or more, and preferably 150 ° C. or less, more preferably 140 ° C. or less. The barrel temperature 3 is preferably 100 ° C. or more, more preferably 110 ° C. or more, and preferably 130 ° C. or less, more preferably 120 ° C. or less. The barrel temperature 4 is preferably 100 ° C. or more, more preferably 110 ° C. or more, and preferably 130 ° C. or less, more preferably 120 ° C. or less. The discharge diameter of the die is preferably 5 mm or more, more preferably 8 mm or more, and preferably 20 mm or less, more preferably 15 mm or less.

  In the above steps, in order to adjust the size of the pores of the porous structure in the absorbent structure, for example, in the case of freeze drying, extrusion foam molding is performed by changing the concentration of the aqueous polysaccharide solution, the freezing temperature and the freezing rate. In this case, the nozzle pressure, the molding temperature, and the addition amount of water, the addition amount of the water-insoluble particles, the type, and the like may be appropriately selected when steam is used for the principle of foaming. In addition, the obtained absorbent structure may be subjected to post-processing, and may be subjected to larger holes, slits, emboss, punching or cutting for changing the outer shape.

  The absorbent structure thus obtained can be used as it is for absorbing a liquid containing water as a component. Alternatively, it can be used in the form of an absorbent article incorporating this absorbent structure. The absorbent articles include, for example, disposable diapers, liners for cloth diapers, sanitary napkins, panty liners, incontinence pads, breast milk pads, pet litter sheets, surgical blood absorbing articles, surgical clothes, bandages, bandages, bed sheets, Pillow covers, absorbent paper for underarm pads, shoe insoles, poultices, and meat and fish meat juice absorbing sheets, etc. may be mentioned.

  Specific examples of the above-mentioned absorbent articles include disposable diapers, which are absorbent articles of body fluid discharged from the human body, sanitary napkins, panty liners, incontinence pads and the like. These body fluid absorbent articles are provided with a skin facing side sheet located closer to the skin of the wearer and a non-skin facing side sheet located farther from the wearer's skin, and the absorbent structure of the present invention It is preferable that the body has a structure disposed between the skin-facing side sheet and the non-skin-facing side sheet. As a skin opposing surface side sheet, the liquid-permeable top sheet which is a sheet located, for example in the side nearest to a wearer's skin is mentioned. Moreover, the sublayer sheet | seat which is a liquid-permeable sheet | seat arrange | positioned adjacent to this surface sheet as a skin opposing surface side sheet | seat is mentioned. On the other hand, as the non-skin facing side sheet, there may be mentioned a liquid impermeable or liquid impervious back sheet, for example, a resin film, a liquid impervious nonwoven fabric and the like.

  Examples of the liquid-permeable top sheet include various nonwoven fabrics and perforated films. Examples of the liquid-permeable sublayer sheet include various nonwoven fabrics. It is preferable that the nonwoven fabric used as a surface sheet or a sublayer sheet is comprised from various resin which has fiber formation ability. In particular, it is preferable that the non-woven fabric is made of a single resin from the viewpoint of the recyclability after separation of the constituent members of the absorbent article (this will be described later). In addition, a plurality of non-woven fabrics made of a single resin may be used. In this case, the resins constituting the non-woven fabric may be the same or different.

  Regardless of the type of surface sheet or sublayer sheet, in the absorbent article provided with the absorbent structure of the present invention, the absorbent structure is preferably in direct contact with the skin-facing side sheet. In this case, when the skin facing side sheet is only the surface sheet, the surface sheet is in direct contact with the absorbent structure. When the skin-facing side sheet includes a top sheet and a sublayer sheet, the sublayer sheet is in direct contact with the absorbent structure. By adopting such a configuration, absorption and retention of the liquid by the thickening effect of the absorbent structure can be efficiently performed.

  From the viewpoint of improving the stability of the outer shape of the absorbent core, the fixability of the pulp and the acrylate crosslinked material, and the transportability of the absorbent core in the production line, an absorbent core composed of a mixture of conventional pulp / acrylate crosslinked materials The entire absorbent core is covered with a sheet material such as nonwoven fabric or tissue paper having an average pore diameter of 20 μm or less to form an absorbent. Having such a configuration in the absorbent article has the advantage that it is possible to add functional agents to the sheet material to add value, but it also impedes the permeability of the liquid from the sheet to the absorbent core. It is a factor. On the other hand, since the whole absorbent structure of the present invention is integrated, the absorbent structure of the present invention can maintain a stable outer shape and can be manufactured. There is no need to cover the outer surface of the absorbent structure with a sheet material. Therefore, it is preferable from the viewpoint of separation during recycling to reduce the number of members other than the absorber and the amount of the adhesive used. Furthermore, the design of the pore size of the absorbent structure can be used to sufficiently exhibit the improvement of the absorption speed and the uptake characteristic of the highly viscous liquid.

  In the above absorbent article provided with the absorbent structure of the present invention, since the absorbent structure contains a water-soluble material exceeding 50 ° C., the absorbent article is By placing in excess water, it is possible to separate the components of the absorbent article. Specifically, the absorbent structural body and the other structural members can be easily separated from the various structural members of the absorbent article. In contrast to this, conventional absorbent articles in which a strong adhesive such as a hot melt adhesive has been used do not easily separate the article into individual components. The fact that the absorbent structure contains a water-soluble material above 50 ° C. is advantageous in that the absorbent structure does not dissolve in the temperature range of human body temperature.

  In addition, conventional absorbent articles have difficulty in separating the absorbent structure from the absorbent articles, that is, separation of excrement, and extra energy is also required for incineration and solid fueling. On the other hand, in the product of the present invention, since separation of the absorbent structure from the absorbent article, that is, separation of excrement is easy, the component after separation is compressed and solidified as it is and used as fuel (thermal recycling) You can also.

  Among the components of the absorbent article produced by the separation, the meltable member can be subsequently reused by heating or melting it. Thus, the absorbent article provided with the absorbent structure of the present invention does not require the process of drying the absorbent polymer to recycle the used absorbent article, unlike the conventional absorbent articles. Therefore, according to the present invention, there is provided a method for recycling components of an absorbent article that is easy to recycle.

  Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the embodiments. For example, although it is preferable that the absorbent article provided with the absorbent structure of the present invention includes the skin facing surface side sheet and the non-skin facing surface side sheet as described above, in addition to this, the specific application of the absorbent article Accordingly, it is possible to provide leak-barrier cuffs extending along the longitudinal direction on both sides along the longitudinal direction on the skin facing surface side. Moreover, you may provide the adhesion layer for fixation with clothing on the surface of a non-skin opposing surface.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the present invention is not limited to such embodiments. Unless otherwise stated, "%" means "mass%".

Example 1
Polysaccharide A and polysaccharide B shown in Table 1 below were mixed with water at a ratio shown in the same table to obtain a viscous liquid. The viscous liquid was placed in a flat bottomed container and frozen. The obtained frozen body was vacuum dried to remove water, to obtain an absorbent structure comprising a plate-like body having a porous structure. Specifically, in a 500 mL beaker, 1.5 parts by mass of xanthan gum (DSP Gokyo Food & Chemical Co., Ltd., Rapport gum GS-C) and locust bean gum (VITOGUM L175 HQ) 1.5, manufactured by Unitech Foods Inc. 97 parts by mass of deionized water was added to the parts by mass to prepare a total of 300 g of a polysaccharide mixture. The beaker was stirred with a stirring blade for 1 hour while warming the periphery of the beaker with a 90 ° C. water bath, and was dissolved so as to be uniform visually. The top of the beaker is covered with a lid to prevent water evaporation. Thereafter, 50 g is put in a metal mold (Sansho long stainless steel long bat deep mold 12 type, length × width × depth mm 120 × 72 × 53) and naturally cooled to room temperature, then a freezer of −80 ° C. Frozen for 1 hour. After that, the lyophilizer was subjected to lyophilization for approximately two days until the drying was completed by the lyophilizer. As a freezer, Deep Freezer LAB-11 manufactured by Kanowo Co., Ltd. was used, and as a freeze dryer, a freeze dryer FDU-1200 manufactured by Tokyo Rika Kikai Co., Ltd. was used.

[Examples 2 to 6]
An absorbent structure was obtained in the same manner as in Example 1 except that polysaccharide A and polysaccharide B shown in Table 1 below were used in the proportions shown in the same table. In Example 2, as polysaccharide B, cationized xanthan gum (DSP Gokyo Food & Chemical Co., Ltd., Rapol gum CX) was used. In Example 3, tara gum (MT-120, manufactured by Mitsubishi Chemical Foods Co., Ltd.) was used as the polysaccharide B. In Example 4, as the polysaccharide B, glutinous starch (waxy starch, manufactured by Nippon Shokuhin Kako Co., Ltd.) was used. In Example 5, pregelatinized starch (waxy alpha D6 manufactured by Nippon Shokuhin Kako Co., Ltd.) was used as the polysaccharide B. In Example 6, a cationized guar gum (Labor gum CG-M, manufactured by Mitsubishi Chemical Foods Co., Ltd.) was used as the polysaccharide A, and guar gum (RG500, manufactured by Mitsubishi Chemical Foods Co., Ltd.) was used as the polysaccharide B.

[Examples 7 to 9]
An absorbent structure was obtained in the same manner as Example 1, except that polysaccharides A shown in Table 1 below were used in the proportions shown in the same table.
In Table 1, Rapole gum GS-C manufactured by DSP Gokyo Food & Chemical Co., Ltd. was used as xanthan gum. As carboxymethylcellulose sodium salt (abbreviated as CMC-Na in the table), CMC 1390 manufactured by Daicel Co., Ltd. was used. Kimica algin IL-2 manufactured by Kimica Co., Ltd. was used as sodium alginate (abbreviated as sodium alginate in the table).

[Comparative Examples 1 and 2]
In Comparative Example 1, a pair of tissue paper on which 5 g / m ² of the hot melt adhesive was spray-coated in advance so as to have a basis weight of 200 g / m ² was used as the superabsorbent polymer (manufactured by Nippon Shokubai Co., Ltd.) , To obtain an absorbent structure. The basis weight of the tissue paper was 16 g / m ² .
In Comparative Example 2, first, 100 parts by mass of the opened fluff pulp (NBKP) and 100 parts by mass of the superabsorbent polymer were uniformly mixed in an air stream to prepare a mixture having a total basis weight of 400 g / m ² . The basis weight of the fluff pulp and the superabsorbent polymer was 200 g / m ² respectively. The fiber stack obtained was wrapped with a tissue paper having a basis weight of 16 g / m ² to obtain an absorbent structure. Between the piled body and the tissue paper, 5 g / m ² of hot melt adhesive was spray coated.

Comparative Example 3
An absorbent structure was obtained in the same manner as Example 1, except that polysaccharides A shown in Table 1 below were used in the proportions shown in the same table. In Table 1, corn starch Y (manufactured by Nippon Shokuhin Kako Co., Ltd.) was used as corn starch.

[Evaluation]
The solubility to a hot water was evaluated about each Example and each comparative example. The evaluation method is as follows. 1.00 g of the absorption structure is precisely weighed, put into a beaker containing 200 g of 50 ° C. deionized water, gradually heated while stirring at 300 rpm using a stirrer and a propeller, and a temperature at which dissolution starts It observed visually. When the content of the beaker started melting at 90 ° C. or less, the uniformity of the solution was judged by visual observation when heated at the dissolution start temperature for 60 minutes. The stirring was performed at 300 rpm by combining stirring blades (four propeller blades) with Tokyo Rika Kikai NZJ-1300 as a stirrer. If it becomes a uniform liquid with a sense of transparency here, it will be judged as "soluble in water exceeding 50 ° C", and if the content of the beaker exceeds 90 ° C, if there is white turbidity or undissolved matter, proceed to the next operation The
The solution after stirring was filtered through a Buchner-Rotte type glass filter (Shibata Scientific Co., Ltd., No. 151G, the size of which was changed as appropriate depending on the filtration efficiency) weighed beforehand after drying, and the residue on the glass filter was weighed. Then, it dried at 105 degreeC for 3 hours, and measured the mass after drying. At this time, when the mass difference between before and after drying with respect to the mass after drying exceeds 30 times, it can be judged that the absorbent structure contains a polymeric absorbent such as a superabsorbent polymer. When the mass difference did not exceed 30 times, it was considered that water-insoluble materials other than the polymer absorbent were used in combination.
Mass difference = (mass before drying-mass after drying) / (mass after drying)
Here, each mass is obtained by weighing the remainder on the glass filter.

  In addition, for each example and each comparative example, while measuring the pore size, 1% deionized water thickening (thickening when 1 part by weight of the absorbent structure is dissolved in 100 parts by weight of deionized water) ) Was measured using a B-type viscometer (B-type viscometer B8M type manufactured by Tokyo Keiki Co., Ltd.) as a measure of the viscosity (30 ° C.) of the liquid. The results are shown in Table 1 below.

  When the solubility to a hot water was evaluated about each Example and each comparative example, all the examples became a transparent uniform liquid and were soluble in water over 50 degreeC. On the other hand, Comparative Examples 1 and 2 in which the polymer absorbent was contained were not dissolved in the hot water, and the mass difference before and after drying exceeded 30 times. Moreover, Comparative Example 3 was insoluble in hot water.

Further, as is clear from the results shown in Table 1, it can be seen that the absorbent structures obtained in the examples have improved viscosity compared to the absorbent structures obtained in the comparative examples.

Claims (9)

  An absorbent structure used to absorb a liquid containing a water-soluble material having a temperature of 50 ° C. and containing water.   The absorbent structure according to claim 1, wherein the material is a polysaccharide and does not contain a water-insoluble polymeric absorbent.   The absorbent structure according to claim 1, wherein the material contains two or more different polysaccharides. Comprising a first polysaccharide and a second polysaccharide different from said first polysaccharide,
The absorbent structure according to claim 3, wherein the second polysaccharide is contained in an amount of 20% by mass or more based on the first polysaccharide.   The absorbent structure according to any one of claims 1 to 4, wherein the absorbent structure is a porous body.   An absorbent article provided with the absorbent structure according to any one of claims 1 to 5.   The absorbent article according to claim 6, further comprising a non-woven fabric, wherein the non-woven fabric is composed of a single resin.   A method of treating an absorbent article, comprising putting the absorbent article according to claim 6 into water exceeding 50 ° C. to separate the constituent members of the absorbent article. The absorbent article according to claim 6 or 7 is placed in water exceeding 50 ° C. to separate the constituent members of the absorbent article, and the meltable resin member produced by the separation is heated or melted, and then re-worked. A method of recycling components of an absorbent article to be used.