JP2005323842A - Water absorbing composite sheet for care sheet, manufacturing method thereof, and care sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a care sheet having excellent fixing property of water absorbing resin, water absorbency of a body liquid, drying property, and handleability. <P>SOLUTION: A water absorbing composite sheet 1 for the care sheet comprises a base material 2 and nearly spherical water absorbing resin particles 3 intermittently fixed to the base material 2. The care sheet 10A has the composite sheet 1 and a non-permeable sheet 12. The sheet 1 is manufactured by sticking droplets containing polymeric monomer and the polymerization promotor of the monomer to the base material 2 and thereafter polymerizing the monomer and the polymerization promotor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-absorbing composite sheet for a care sheet excellent in water absorption and handling, a method for producing the same, and a care sheet using the water-absorbing composite sheet for a care sheet.

  Non-permeable nursing sheets are used on the beds of sick persons, bedridden elderly people, and demented patients who cannot excrete by themselves, so as not to get dirty due to incontinence. However, in the non-permeable care sheet, body fluids such as urine do not ooze out under the care sheet, but return to the user's body, causing unpleasant feelings and propagation of germs. Or

  Therefore, a care sheet in which an absorbent body sandwiched between a water-absorbent resin and the like with tissue or pulp is sandwiched between a water-permeable sheet and a water-impermeable sheet is used. Since this care sheet is generally disposable, the amount of pulp is reduced to reduce the bulk so that as much of the replacement care sheet can be stocked as possible in a limited place. There is a tendency to use a large amount of water-absorbing resin to supplement the amount of absorption.

  In such a care sheet, when the user moves his / her body on the care sheet, the water-absorbent resin which is not fixed inside moves as a result of kinking or dragging, and agglomeration And the site | part which a water absorbing resin does not exist generate | occur | produces. In particular, although the water-absorbing resin moves at the hip position and the amount of the water-absorbing resin decreases, there is a problem that body fluid leaks when the user incontinence is performed in a portion where the water-absorbing resin does not exist. On the contrary, there is a case where the water-absorbing resin becomes mummy by absorbing the body fluid at the portion where the water-absorbing resin is agglomerated, and sufficient absorption cannot be performed.

  Therefore, a method of forming an absorbent core by quilting or needle punching is also adopted, but the water-absorbing resin passes through the fibers due to the impact force of the quilting or needle punch, etc. There is a problem that the product is damaged or the product is leaked from the care sheet.

  Therefore, in order to prevent the water-absorbing resin from moving, a method of fixing the water-absorbing resin with an adhesive, a method of heat-sealing the heat-absorbing resin by sandwiching the water-absorbing resin with a heat-fusible fiber nonwoven fabric, and the like are also performed. However, in such a case, there are problems such that absorption is inhibited and the body fluid cannot be sufficiently absorbed, or the absorbent body becomes plate-like and loses flexibility.

Japanese Patent Application Laid-Open No. 11-244126 discloses a technique in which a water-absorbing resin is present in a concave portion of a sheet having an uneven shape so that the water-absorbing resin does not move before and after absorption. When a large amount of body fluid is absorbed, there is a problem that the body fluid cannot be sufficiently absorbed due to inhibition of swelling of the water-absorbent resin present in the recess.
Japanese Patent Laid-Open No. 11-244126

  An object of the present invention is to solve the above-mentioned conventional problems and to provide a care sheet excellent in fixability and handleability of a water absorbent resin.

  In particular, the present invention is that the water-absorbent resin is stably present in the care sheet without moving, has good shape retention and flexibility before absorption of body fluids, and absorbs quickly and uniformly upon absorption of body fluids to swell. And it aims at providing the care sheet which can be used stably even in this state.

  The water-absorbent composite sheet for a care sheet according to claim 1 has a base material and substantially spherical water-absorbent resin particles intermittently fixed to the base material.

  The water-absorbing composite sheet for a care sheet according to claim 2, wherein the first water-absorbing resin is disposed on the base material, and then a polymerizable monomer capable of forming the second water-absorbing resin and a polymerization product of the monomer. The first water-absorbing resin is intermittently fixed onto the base material by the second water-absorbing resin by causing the monomer and the polymerized product to polymerize by attaching droplets containing the polymer onto the base material. It is characterized by letting it be.

  Since this water-absorbing composite sheet for a care sheet is obtained by adhering a water-absorbing resin to the base material, it can be applied to the base material before absorption of bodily fluids or after gelation due to absorption of bodily fluids. On the other hand, the water-absorbing resin is stably fixed, and the water-absorbing resin is stably present without moving in the care sheet. For this reason, the water-absorbing resin moves and agglomerates, so that the body fluid is not absorbed at the time of absorbing the body fluid, and the body fluid is surely absorbed without the occurrence of a portion where the water-absorbing resin is not present and the body fluid leaking out. be able to.

  Moreover, since the water-absorbing resin is fixed intermittently to the base material, that is, in a discontinuous manner, it has flexibility and can be easily deformed, so that it can be in close contact with the movement of the user's body. Yes, you can restore it to its original state by re-laying it after it has been kinked and wrinkled.

  This water-absorbing composite sheet for a care sheet may carry a substance having any of the functions of bacteriostatic, sterilization, antibacterial, alteration of water-absorbing resin, and aroma. And it becomes possible to use it comfortably.

  As a base material of the water-absorbent composite sheet for care sheet of the present invention, a water-permeable network structure is preferable.

  The care sheet of the present invention has such a water-absorbent composite sheet for care sheet of the present invention and a water-impermeable sheet provided on the water absorbent resin fixing surface side or the opposite surface side. Excellent body fluid absorption and handling.

  In the care sheet in which a water-impermeable sheet is provided on the surface opposite to the water-absorbing resin fixing surface of the water-absorbing composite sheet, the water-permeable sheet may be provided on the water-absorbing resin fixing surface side.

  The method for producing a water-absorbing composite sheet for a care sheet according to claim 8 is a method for producing the water-absorbing composite sheet for a care sheet according to claim 1, wherein the polymerizable monomer capable of producing a water-absorbing resin and the monomer are produced. A care product in which substantially spherical water-absorbent resin particles are intermittently fixed on a base material by allowing the monomer and the polymerization progress matter to polymerize after the droplets containing the polymerization progressing substance are adhered to the base material. It is characterized by manufacturing a water-absorbing composite sheet for use in a sheet.

  The method for producing a water-absorbing composite sheet for a care sheet according to claim 9 is a method for producing the water-absorbing composite sheet for a care sheet according to claim 2, wherein the first water-absorbing resin is disposed on the substrate. Thereafter, a droplet containing a polymerizable monomer capable of producing a second water-absorbent resin and a polymerization product of the monomer is attached onto the substrate to polymerize the monomer and the polymerization product, A water-absorbing composite sheet for a care sheet in which the first water-absorbing resin is intermittently fixed on the substrate by the second water-absorbing resin is produced.

  In the water-absorbing composite sheet for a care sheet of the present invention, the water-absorbing resin is stably fixed to the base material regardless of before and after the absorption of the body fluid, and the shape stability is high over a long period of time and the flexibility is high. Moreover, it is excellent in the absorptivity by a water absorbing resin. Therefore, if it is the care sheet of this invention which has arrange | positioned the water-impermeable sheet | seat on the single side | surface of such a water-absorbing composite sheet for care sheets of this invention, it can be used comfortably by the softness | flexibility, The body fluid can be reliably absorbed with good absorbability.

  In addition, the water-absorbent composite sheet for a care sheet of the present invention carries a substance or any other functional material having any of the functions of bacteriostatic, bactericidal, antibacterial, alteration of water-absorbing resin, and fragrance on a base material. Accordingly, various functions can be imparted, and further excellent effects are expected.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[Water-absorbing composite sheet for care sheet]
First, the water-absorbent composite sheet for care sheet of the present invention will be described.

  Fig.1 (a) is typical sectional drawing which shows an example of embodiment of the water absorptive composite sheet for care sheets of this invention, FIG.1 (b) is the perspective view.

  A water-absorbing composite sheet 1 for a care sheet shown in FIGS. 1 (a) and 1 (b) is obtained by intermittently fixing substantially spherical water-absorbing resin particles 3 to a base material 2.

  As the base material 2, in the manufacturing process of the water-absorbing composite sheet for a care sheet of the present invention described later, the liquid droplets in the course of polymerization can be adhered, and flexibility that is an important characteristic of the care sheet, for example, It is desirable that it is made of a material having high water permeability so that it can be easily changed in shape by human power, and can be immediately contacted with body fluids to be absorbed by the care sheet. A water-permeable network structure is particularly preferable.

  Here, the network structure includes a planar or two-dimensional network structure and a spatial or three-dimensional network structure. Examples of the two-dimensional network structure include a thin nonwoven fabric, a fabric, a net structure obtained by extrusion molding of a thermoplastic plastic, a network structure of a thermoplastic fiber, and a metal network structure. Examples of the three-dimensional network structure include a laminate of the two-dimensional network structure, a thick nonwoven fabric, a fiber cotton, and a porous plastic plate having independent or open cells.

  As the substrate 2, a nonwoven fabric or a fabric is particularly preferable.

  Regardless of the regular shape or indefinite shape of the outer shape, the base material exhibits the network structure composed of a large number of voids and through-holes and a skeleton portion for molding them. In the case of a nonwoven fabric, regardless of whether the fiber entanglement is fusion, adhesion, or simple mechanical entanglement, the strength of the entanglement is not limited, but a strength that can be easily deformed manually is desirable.

  The material of the base material is preferably fiber, and the fiber is natural fiber (cellulosic as plant fiber, for example, pulp, waste paper, paper, cotton, hemp, straw, bamboo, sawdust, etc., animal fiber is silk, wool Etc.), artificial fibers (cellulosic materials such as acetate and rayon), synthetic fibers (polyethylene, polypropylene, polyester, acrylic, polyamide, etc.), inorganic fibers (glass fiber, quartz fiber, asbestos, perlite, etc.), etc. . Further, in view of environmental problems, synthetic fibers such as biodegradable polylactic acid fibers and aliphatic polyesters may be used instead of synthetic fibers that are not biodegradable. Two or more of these may be mixed and used.

  The substrate is not limited to fibers, but may be a woven fabric woven with slit yarns having slits made of water-permeable films or sheets.

  When a thermoplastic resin is used as the substrate, it can be heat sealed and fixed or folded into a bag shape.

  The thickness, basis weight, etc. of the substrate are appropriately determined in consideration of the required strength, water permeability, etc., but the thickness is preferably 1-20 mm (under 0.2 psi pressure), In particular, 1 to 10 mm, particularly 1 to 5 mm is preferable.

  The water-absorbing resin constituting the water-absorbing resin particles 3 is a resin that can quickly absorb water several tens to several hundreds times its own weight. The water absorbing performance of the water absorbent resin is preferably 5 to 60 g-water / g-water absorbent resin per water absorbent resin. If the water absorption performance of the water absorbent resin is lower than this range, a large amount of water absorbent resin is required to obtain the required water absorption, which is uneconomical. If the water absorption is higher than this range, the gel strength becomes too low when absorbing the body fluid of the water-absorbent resin, and gel blocks (soft gels deform to form a film) are generated. Leakage may occur.

  The particle size of the water-absorbent resin particles 3 is not particularly limited, but is preferably 10 to 5,000 μm in average particle size, more preferably 50 to 3,000 μm, and particularly preferably 100 to 2,000 μm. . If the average particle diameter of the water-absorbing resin particles 3 is too small, the water-absorbing resin particles 3 may not be fixed on the base material. If the average particle size is too large, the fixing strength to the base material 2 per particle will be low. It is easy to fall off.

  The water absorbent resin particles 3 are fixed to the base material 2 intermittently, that is, discontinuously. The water-absorbent resin particles 3 are fixed to the base material 2 intermittently, whereby the flexibility required for the care sheet can be obtained. If the water-absorbing resin particles are continuously fixed on the base material and are connected to form a plate shape, the flexibility of the care sheet is impaired, and the intended flexibility of the present invention cannot be obtained. Moreover, it leads to a decrease in absorption rate and absorption capacity.

  Note that the water-absorbing resin particles 3 are fixed to the substrate 2, for example, as described later, after a droplet containing a polymerizable monomer and a polymerization product of the monomer is attached to the substrate, It means that a water-absorbent resin is fixed on a substrate by polymerizing a polymerizable monomer and a polymerization product of the monomer.

  In general, the water-absorbent resin particles 3 are preferably fixed uniformly and intermittently on the base material 2, but may be fixed non-uniformly and intermittently on the base material 2, for example, The arranged portions of the water-absorbent resin particles 3 may be formed in a gradation, stripe, houndstooth, or checkered pattern. Further, the water-absorbent resin particles 3 may be intermittently fixed on the base material 2 one by one, and a plurality of particles adhering to each other in a bowl shape are fixed intermittently. Also good. By doing so, it is possible to prevent the mamacho phenomenon during absorption of body fluid, improve the absorption rate, and ensure flexibility.

If the amount of the water-absorbing resin particles 3 fixed to the substrate 2 is too small, sufficient body fluid absorbability cannot be obtained. If it is too large, the water-absorbing resin particles are connected to each other to form a hard plate. , Loss of flexibility. Therefore, the fixed amount of the water-absorbent resin particles 3 varies depending on the structure of the substrate 2 and the required body fluid absorbability, but the basis weight is 50 to 1,000 g / m ² , particularly 50 to 500 g / m ^2. It is preferable that However, even when the amount of the water-absorbing resin particles 3 fixed to the base material 2 is large, the water-absorbing resin particles 3 are aggregated in a hook shape on the base material 2 and fixed, thereby allowing flexibility due to intermittent fixing. In addition, the amount of fixation can be increased and the body fluid absorbability can be increased.

  The care sheet of the present invention has, in addition to the water absorbent resin fixed to the base material, a free water absorbent resin that is not fixed to the base material and can be easily peeled off. You may do it. In this case, the kind of the free water-absorbing resin may be the same as or different from the water-absorbing resin particles 3 fixed to the substrate 2, and the shape thereof is not particularly limited. The shape is not limited to a granular shape, and may be a fibrous shape, a flake shape, a crushed shape, a film shape, or other various shapes.

  In the case where a water-absorbing resin different from the water-absorbing resin particles 3 fixed to the substrate 2 is supported to improve the body fluid absorption performance, the first water-absorbing resin is formed on the substrate as described later. And then a droplet containing a polymerizable monomer capable of producing a second water-absorbing resin and a polymerization product of the monomer is deposited on the substrate to polymerize the monomer and the polymerization product. Thus, the first water-absorbing resin can be intermittently fixed on the substrate by the second water-absorbing resin (corresponding to the water-absorbing resin particles 3 described above).

Examples of the first water-absorbing resin for improving the water absorption include the following.
(1) Anionic water-absorbing resin As the anionic water-absorbing resin, a commercially available anionic water-absorbing resin can be used. For example, there are the following water-soluble ethylenically unsaturated monomer homo- or copolymer resins. Examples of such monomers include acrylic acid, methacrylic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, vinyl Examples thereof include sulfonic acid, (meth) allylsulfonic acid, and alkali metal salts and ammonium salts thereof, and one or more of these can be used. Acrylic acid and 2- (meth) acryloylethanesulfonic acid or a salt thereof are preferred.
(2) Cationic water-absorbing resin Commercially available cationic water-absorbing resins can also be used as the cationic water-absorbing resin. For example, polyallylamine, polyalkylenepolyamine, polyethyleneimine, polyvinylamine, Mannich reaction product of poly (meth) acrylamide, poly (meth) acrylamine, dialkylaminoalkyl (meth) acrylate: N, N-dimethylaminoethyl (meth) Acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminobutyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate homo resin or copolymer resin with (meth) acrylamide, Dialkylaminoalkyl (meth) acrylates made from quaternized ammonium salts with alkyl halides (for example, methyl chloride, ethyl chloride, methyl bromide, etc.) or copolymer resins thereof with (meth) acrylamide, polydia Kill allylamine quaternary ammonium salts, quaternized vinyl benzyl amine resin, acetylated chitosan, crosslinked polycationic condensation reaction product of epichlorohydrin and polyvalent amine or monoamine.
(3) Nonionic water-absorbing resin Nonionic water-absorbing resins include polyethylene oxide, polypropylene oxide, ethylene oxide / propylene oxide copolymer, N-vinylcarboxylic acid amide polymer, polyvinyl alcohol, and polyvinyl acetate. A crosslinked body can be used. In particular, a crosslinked polyalkylene oxide such as polyethylene oxide is preferred.

  These water-absorbing resins may be used in the form of a cross-linking before or after sheet formation for the purpose of maintaining the sheet shape in the presence of body fluid.

  By supporting the anionic water-absorbing resin on a base material, a metal having a valence of 2 or more can be captured to increase the water absorption capacity. Moreover, the water absorption capacity of the aqueous solution containing metal ions can be increased by supporting the cationic water absorbent resin. Further, by supporting the nonionic water-absorbing resin, the water absorption ability of the aqueous solution containing the electrolyte can be increased. These water absorbent resins (first water absorbent resins) may be used alone or in combination of two or more.

  Even if the first water-absorbing resin is in the form of fine powder, it can be stably fixed on the substrate by the adhesion force of the droplets during polymerization as described later. Further, a water-absorbing resin having the same or larger average particle size as that of droplets in the polymerization process described later may be used. For example, a water-absorbing resin having better water-absorbing performance than particles in the course of polymerization or a non-manufactured product and waste water from various water-absorbing material products may be used.

  However, if the first water absorbent resin is too large, the first water absorbent resin may be granular because the second water absorbent resin particles may not be stably fixed to the substrate. In this case, the average particle size is preferably 1,000 μm or less, and is preferably about 300 to 800 μm, for example, in consideration of handleability.

The amount of the first water-absorbent resin supported on the substrate varies depending on the required body fluid absorbability and the amount of the second water-absorbent resin used, but the basis weight is 10 to 1, 000 g / m ² is preferable, 10 to 500 g / m ² is more preferable, and 10 to 300 g / m ² is particularly preferable.

  The water-absorbent composite sheet for a care sheet of the present invention has functionalities such as an antibacterial agent, a bactericide, a bacteriostatic agent, a stabilizer that prevents decomposition and alteration of the resin, a fragrance, and a deodorant. Functionality can be enhanced by loading a substance.

  Among these, as stabilizers for preventing resin decomposition / degeneration by the absorbing liquid, stabilizers for preventing decomposition / degeneration of the water-absorbent resin by body fluids (ie, urine, feces) and body fluids (body fluids such as blood and secretions). Can be mentioned. JP-A-63-118375 discloses a method for containing an oxygen-containing reducing inorganic salt and / or an organic antioxidant in a polymer, JP-A-63-153060 discloses a method for containing an oxidizing agent, JP 63-127754 A contains an antioxidant, JP 63-272349 A contains a sulfur-containing reducing agent, JP 63-146964 contains a metal chelating agent. JP-A 63-15266 discloses a method containing a radical chain inhibitor, JP-A 1-275661 discloses a phosphinic acid group- or phosphonic acid group-containing amine compound or a salt thereof, Japanese Laid-Open Patent Application No. 64-29257 discloses a method of containing a polyvalent metal oxide, Japanese Patent Application Laid-Open No. 2-255804, Japanese Patent Application Laid-Open No. 3-179008 discloses polymerization. A method in which the coexistence of a water-soluble chain transfer agents have been proposed. All of these can be used in the present invention. In addition, JP-A-6-306202, JP-A-7-53884, JP-A-7-62252, JP-A-7-113048, JP-A-7-145326, JP-A-7-145263, The materials and methods described in JP-A-7-228788 and JP-A-7-228790 can also be used. Specific examples include potassium oxalate titanate, tannic acid, titanium oxide, phosphinic acid amine (or salt thereof), phosphonic acid amine (or salt thereof), metal chelate and the like.

  Antibacterial agents are used in order to prevent spoilage due to the absorbed liquid. As antibacterial agents, for example, “New development of bactericidal / antibacterial technology”, pages 17-80 (Toray Research Center (1994)), “Testing / evaluation methods and product design of antibacterial / antifungal agents”, pages 128-344 (NTT) S (1997)), Japanese Patent No. 2760814, Japanese Unexamined Patent Publication No. 39-179114, Japanese Unexamined Patent Publication No. 56-31425, Japanese Unexamined Patent Publication No. 57-25813, Japanese Unexamined Patent Publication No. 59-189854, JP 59-105448, JP 60-158861, JP 61-181532, JP 63-135501, JP 63-139556, JP 63-156540. JP-A-64-5546, JP-A-64-5547, JP-A-1-153748, JP-A-1-221242, JP-A-2-253. No. 47, JP-A-3-59075, JP-A-3-103254, JP-A-3-221141, JP-A-4-11948, JP-A-4-92664, JP-A-4-138165. JP-A-4-266947, JP-A-5-9344, JP-A-5-68694, JP-A-5-161671, JP-A-5-179053, JP-A-5-269164, Those introduced in JP-A-7-165981 can be appropriately selected.

  Examples thereof include alkylpyridinium salts, benzalkonium chloride, chlorhexidine gluconate, pyridione zinc, silver-based inorganic powders, and the like. Representative examples of the quaternary nitrogen-based antibacterial reagent include methylbenzethonium chloride, benzalkonium chloride, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and hexadecyltrimethylammonium bromide. Examples of heterocyclic quaternary nitrogen-based antibacterial reagents include dodecylpyridinium chloride, tetradecylpyridinium chloride, cetylpyridinium chloride (CPC), tetradecyl-4-ethylpyridinium chloride, and tetradecyl-4-methylpyridinium chloride.

  Other preferred antibacterial reagents include bis-biguanides. These are described in detail, for example, in US Pat. Nos. 2,684,924, 2,990,425, 2,830,006 and 2,863,019. It is described in. The most preferred bis-biguanide is 1,6-bis (4-chlorophenyl) diguanide hexane, which is known as chlorohexidine and its water-soluble salts. Particularly preferred are chlorohexidine hydrochloride, acetate and gluconate.

  Several other types of antibacterial reagents are also useful. For example, carbanilides, substituted phenols, metal compounds, and rare earth salts of surfactants can be exemplified. The carbanilide includes 3,4,4′-trichlorocarbanilide (TCC, triclocarban) and 3- (trifluoromethyl-4,4′-dichlorocarbanilide (IRGASAN). Mention may be made of 5-chloro-2- (2,4-dichlorophenoxy) phenol (IRGASAN DP-300), which include zinc and tin salts such as zinc chloride, zinc sulfide and tin chloride. A rare earth salt of a surfactant is disclosed in European Patent Publication No. 10819. Examples of this type of rare earth salt include a lanthanum salt of a linear alkylbenzene sulfonate having 1 to 18 carbon atoms. it can.

  Further, deodorizers, deodorizers and fragrances are used to prevent or alleviate the unpleasant odor of the absorbed liquid. Examples of the deodorant, deodorant, and fragrance are “new deodorant / deodorant and technology and prospect” (Toray Research Center (1994)), JP-A-59-105448, JP-A-60-158861, JP-A-61-118132, JP-A-1-153748, JP-A-1-221242, JP-A-1-265156, JP-A-2-41155, JP-A-2-253847, Those introduced in Japanese Laid-Open Patent Publication Nos. 3-103254, 5-269164, 5-123358, and 5-277143 can be selected as appropriate. Specifically, examples of the deodorizer and deodorizer include iron complexes, tea extraction components, activated carbon, clay, zeolite, and the like. Examples of fragrances include fragrances (citral, cinnamic aldehyde, heliotopine, camphor, bornyl acetate) wood vinegar, paradichlorobenzene, surfactants, higher alcohols, terpene compounds (limonene, pinene, camphor, borneol, eucalyptol, Eugenol).

The loading amount of these functional substances varies depending on the type of functional substance used and the required functionality, but is preferably 10 to 1,000 g / m ² as the basis weight with respect to the substrate, and more preferably 50 ˜500 g / m ² is preferable, and 50 to 300 g / m ² is particularly preferable.

  Further, fibrous materials such as pulp and chemical fibers, silica powders used for preventing blocking of known water-absorbing resins, and the like may be disposed on the substrate.

(Method for producing a water-absorbent composite sheet for a care sheet)
Hereinafter, preferred embodiments of the method for producing a water-absorbing composite sheet for a care sheet of the present invention will be described. However, the method for producing the water-absorbing composite sheet for a care sheet of the present invention is limited to the following methods. It is not something.

  Usually, the water-absorbent composite sheet for a care sheet of the present invention is produced by sequentially performing a step of fixing water-absorbent resin particles to a substrate and a surface cross-linking step of the water-absorbent resin. In the case where substances having antibacterial and deodorizing ability or other functional substances are supported on the base material, these substances are applied on the base material before the step of fixing the water-absorbing resin particles on the base material. Perform the process. Hereinafter, each step will be described.

[1] Step of imparting antibacterial and deodorant substances or other functional substances on the substrate As described above, the substrate includes other water-absorbent resins, antibacterial agents, bactericides, and bacteriostatic agents. , Stabilizers that prevent the decomposition and alteration of resins, fibrous materials such as fragrances, pulp and chemical fibers, silica powders used to prevent blocking of known water-absorbing resins (hereinafter referred to as “functional substances”) Etc.)). In this case, these functional substances and the like can be placed on the base material in advance and fixed to the base material so as to attach a droplet described later during polymerization. That is, since the droplets in the course of polymerization have adhesiveness, these functional substances and the like are entrapped and attached to the substrate, and these can be easily fixed on the substrate.

  Therefore, it is possible to stably fix a functional substance or the like smaller than the average particle diameter of particles obtained by polymerizing droplets in the polymerization to a large functional substance on the substrate. That is, in ordinary care sheets, fine powders cannot be used because they leak out of the surface sheet, agglomerate for easy mobility, or scatter as dust. Since it can adhere to a functional substance etc. and can be fixed to a base material, it can be used without leaking from a surface sheet (a non-permeable sheet or a permeable sheet described later).

[2] Step of fixing water-absorbing resin particles on a substrate The step of fixing water-absorbing resin particles on a substrate is preferably an aqueous solution of a polymerizable monomer that gives a water-absorbing resin, for example, an aliphatic unsaturated carboxylic acid. A redox polymerization initiator is arranged in an aqueous solution of a polymerizable monomer containing an acid or a salt thereof as a main component to start polymerization of the monomer, and a reaction mixture in progress of polymerization including the monomer after starting the reaction and the produced polymer is removed. It is carried out by forming a droplet in the phase, bringing it into contact with the substrate, forming a precursor of the water-absorbent resin particles, and completing the polymerization, whereby the water-absorbent resin particles adhere to the substrate. A water-absorbing composite sheet for a care sheet.

  One preferred method for polymerizing droplets in the gas phase is to use a first liquid composed of an aqueous solution of a polymerizable monomer containing one of an oxidizing agent and a reducing agent constituting a redox polymerization initiator, and a redox polymerization initiator. On the other hand, the polymerization is started by mixing in a gas phase with a second liquid consisting of an aqueous solution containing a polymerizable monomer if desired.

  As specific means, for example, as shown in the examples described later, the first liquid and the second liquid that collide with the liquid flowing out of the nozzle collide with each other at an angle of 15 degrees or more and in a liquid column state. Thus, there is a method of ejecting from separate nozzles. In this way, by causing the two liquids to collide with each other at an intersecting angle, a part of the outflow energy from the nozzle is used for mixing. The crossing angle between the first liquid and the second liquid flowing out from each nozzle is appropriately selected according to the properties of the polymerizable monomer to be used, the flow rate ratio, and the like. For example, if the linear velocity of the liquid is high, the crossing angle can be reduced.

  In this case, the temperature of the first liquid is usually 10 to 80 ° C., preferably 20 to 60 ° C., more preferably 25 to 50 ° C., and the temperature of the second liquid is also usually room temperature to 80 ° C., preferably It is 20-60 degreeC, More preferably, it is 25-50 degreeC.

  In this way, the respective aqueous solutions ejected from the nozzles collide in a liquid column state to combine both liquids. After the coalescence, a liquid column is formed and the state is maintained for a certain period of time, but the liquid column is then disassembled into droplets. The generated droplets undergo polymerization in the gas phase.

  In order for the polymerization of the droplets to proceed and contact the substrate to form suitable water-absorbent resin particles, the droplet diameter is particularly preferably in the range of 10 to 10,000 μm. That is, when the diameter of the droplet is less than 10 μm, the fine droplet adheres to the reactor or is flowed by an air current and cannot be stably fixed to the substrate. If it exceeds 10,000 μm, the spherical shape may not be maintained by its own weight when the droplet reaches the substrate.

  As the gas phase gas that provides a reaction field for starting the polymerization and forming droplets during the polymerization, nitrogen, helium, carbon dioxide, or the like, which is inert to the polymerization, is preferable, but air may also be used. In addition, there is no particular limitation on the humidity in the gas, including the case of only water vapor, but if the humidity is too low, the water in the aqueous monomer solution evaporates and the monomer precipitates before the polymerization proceeds. There is a possibility that the polymerization rate is remarkably reduced or the polymerization is stopped midway. The temperature condition of the gas is 20 ° C. or higher and 150 ° C. or lower, desirably 100 ° C. or lower. The gas flow direction may be either counter-current or co-current with respect to the liquid column and the traveling direction of the droplets. However, when the residence time of the droplets in the gas phase needs to be increased, that is, the polymerization rate of the polymerizable monomer is increased. If it is necessary to increase the viscosity of the droplets and thus increase the viscosity of the droplets, the countercurrent (antigravity direction) is better.

  The reaction raw materials used in the polymerization step will be described below.

(1) Polymerizable monomer The polymerizable monomer to be used is not particularly limited as long as it provides a water-absorbing resin, but it is particularly preferable to use a polymerizable monomer whose polymerization is initiated by a redox initiator. In general, the polymerizable monomer is preferably water-soluble.

  A typical example of such a polymerizable monomer, which is preferable for the present invention, is an aliphatic unsaturated carboxylic acid or a salt thereof. Specific examples include unsaturated monocarboxylic acids or salts thereof such as acrylic acid or salts thereof, methacrylic acid or salts thereof; or unsaturated dicarboxylic acids or salts thereof such as maleic acid or salts thereof, itaconic acid or salts thereof, etc. These may be used alone or in admixture of two or more. Among these, acrylic acid or a salt thereof and methacrylic acid or a salt thereof are preferable, and acrylic acid or a salt thereof is particularly preferable.

  As the polymerizable monomer that gives the water-absorbent resin used in the present invention, an aliphatic unsaturated carboxylic acid or a salt thereof is preferable as described above. Therefore, an aliphatic unsaturated carboxylic acid or a salt thereof is mainly used as the aqueous solution of the polymerizable monomer. An aqueous solution as a component is preferred. Here, “the main component is an aliphatic unsaturated carboxylic acid or salt thereof” means that the aliphatic unsaturated carboxylic acid or salt thereof is 50 mol% or more, preferably 80 mol%, based on the total amount of the polymerizable monomers. This means that it is included.

  As the salt of the aliphatic unsaturated carboxylic acid, a water-soluble salt such as an alkali metal salt or an ammonium salt is usually used. The degree of neutralization is appropriately determined according to the purpose, but in the case of acrylic acid, 20 to 90 mol% of the carboxyl group is preferably neutralized with an alkali metal salt or ammonium salt. When the degree of partial neutralization of the acrylic acid monomer is less than 20 mol%, the water absorption ability of the water absorbent resin to be produced tends to be remarkably lowered.

  For neutralization of the acrylic acid monomer, one or more of alkali metal hydroxide, bicarbonate, etc. or ammonium hydroxide can be used, preferably alkali metal hydroxide, Specific examples thereof include sodium hydroxide and potassium hydroxide.

  In the present invention, in addition to the aliphatic unsaturated carboxylic acid or a salt thereof, a polymerizable monomer copolymerizable with these, for example, (meth) acrylamide, (poly) ethylene glycol (meth) acrylate, 2- Although it is hydroxyethyl (meth) acrylate and other low water-soluble monomers, alkyl acrylates such as methyl acrylate and ethyl acrylate may be used in amounts that do not deteriorate the performance of the resulting water-absorbent resin. There is no problem. In the present specification, the term “(meth) acryl” means both “acryl” and “methacryl”. Of these polymerizable monomers, those that give a water-absorbing resin are not used as auxiliary components for aliphatic unsaturated carboxylic acids or salts thereof, but as the main monomer of an “aqueous solution of a polymerizable monomer that gives a water-absorbing resin”. You can also

  The concentration of the polymerizable monomer in the polymerizable monomer aqueous solution containing the above-mentioned aliphatic unsaturated carboxylic acid or a salt thereof as a main component is 20% by weight or more, preferably 25% by weight or more. If this concentration is less than 20% by weight, the water-absorbing ability of the water-absorbent resin after polymerization cannot be obtained sufficiently, which is not preferable. The upper limit is preferably about 80% by weight from the handling of the polymerization reaction solution.

(2) Cross-linking agent Aliphatic unsaturated carboxylic acid or its salt, especially acrylic acid or its salt, may form a self-crosslinking polymer by itself. It can also be formed. When a crosslinking agent is used in combination, the water absorption performance of the water absorbent resin that is generally produced is improved. As a crosslinking agent, it reacts with a polyvalent vinyl compound copolymerizable with the polymerizable monomer, for example, N, N′-methylenebis (meth) acrylamide, (poly) ethylene glycol poly (meth) acrylates, and carboxylic acid. A water-soluble compound having two or more functional groups that can be used, such as polyglycidyl ethers such as ethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether, is preferably used. These may be used alone or in combination of two or more. Among these, N, N′-methylenebis (meth) acrylamide and (poly) ethylene glycol di (meth) acrylate are particularly preferable. The amount of the crosslinking agent used is usually 0.001 to 10% by weight, preferably 0.01 to 5% by weight, more preferably 0.01 to 3% by weight, based on the charged amount of the polymerizable monomer.

(3) Polymerization initiator As the polymerization initiator, those generally used in aqueous radical polymerization can be used. Examples of such initiators include inorganic and organic peroxides such as persulfates such as ammonium and alkali metals, particularly potassium, hydrogen peroxide, t-butyl peroxide, and acetyl peroxide. Furthermore, initiators known as azo compounds can also be used. For example, 2,2′-azobis (2-amidinopropane) dihydrochloride, which shows water solubility to some extent, can be mentioned. These may be used alone or in combination of two or more.

  Polymerization is initiated by decomposition of the radical polymerization initiator. A commonly known technique is pyrolysis. Often, a polymerization initiator that has not been heated is added to the polymerizable monomer in the reaction solution that has been heated to the decomposition temperature of the polymerization initiator in advance to initiate the polymerization. Belongs.

  The radical polymerization initiator particularly preferably used in the present invention is a combination of an oxidizing agent and a reducing agent that forms a water-soluble redox system to some extent.

  Examples of the oxidizing agent include hydrogen peroxide, persulfates such as ammonium persulfate and potassium persulfate, t-butyl hydroperoxide, cumene hydroperoxide, ceric salt, permanganate, and chlorite. 1 type, or 2 or more types, such as a salt and hypochlorite, are mentioned. Among these, hydrogen peroxide is particularly preferable. The amount of these oxidizing agents used is usually 0.01 to 10% by weight, preferably 0.1 to 2% by weight, based on the polymerizable monomer.

  The reducing agent is capable of forming a redox system with the above oxidizing agent, specifically, sulfites such as sodium sulfite and sodium bisulfite, sodium thiosulfate, cobalt acetate, copper sulfate, ferrous sulfate, L- 1 type (s) or 2 or more types, such as ascorbic acid or an alkali metal salt of L-ascorbic acid, can be mentioned. Among these, L-ascorbic acid or L-ascorbic acid alkali metal salt is particularly preferable. The amount of these reducing agents to be used is usually 0.001 to 10% by weight, preferably 0.01 to 2% by weight, based on the polymerizable monomer.

[3] Surface cross-linking step The surface of the water-absorbent resin can be cross-linked with a cross-linking agent for the purpose of improving water absorption performance. In general, it is known to improve the properties of resin particles by applying an appropriate amount of moisture together with a crosslinking agent to the surface of powdered water-absorbent resin particles, and then heating to crosslink the surface. As a result of the formation of a crosslinked structure, it is considered that the shape can be maintained without inhibiting the swelling when water is absorbed and swollen. In this step, first, a solution of a surface cross-linking agent is applied on a substrate on which water-absorbing resin particles are supported. As the surface cross-linking agent, polyfunctional compounds that can be copolymerized with polymerizable monomers such as N, N′-methylenebis (meth) acrylamide and (poly) ethylene glycol di (meth) acrylate, (poly) ethylene glycol diglycidyl ether, etc. A compound having a plurality of functional groups capable of reacting with the carboxylic acid group is used. These surface crosslinking agents are usually used in an amount of 0.1 to 1% by weight, preferably 0.2 to 0.5% by weight, based on the water-absorbent resin particles. These surface cross-linking agents are diluted with water, ethanol, methanol or the like so as to be uniformly applied to the water-absorbent resin particles, and 0.1 to 1% by weight, particularly 0.2 to 0.5% by weight. It is preferable to use it as a solution. The application of the crosslinking agent solution is usually preferably carried out by spraying the crosslinking agent solution onto the water-absorbent resin particles on the substrate using a sprayer or applying the crosslinking agent solution with a roll brush. In addition, after adding a crosslinking agent solution excessively, you may make it remove excessive surplus crosslinking agent solution by squeezing lightly to such an extent that a resin particle is not crushed with a pressing roll, or blowing a wind. The application of the crosslinking agent solution may be performed at room temperature. The water-absorbing resin particles to which the cross-linking agent solution has been applied are then heated to cause a cross-linking reaction to selectively form a cross-linking structure on the water-absorbing resin surface. The conditions for the cross-linking reaction may be appropriately selected depending on the cross-linking agent to be used.

  In the present invention, an unsaturated carboxylic acid polymer crosslinked product is particularly preferable as the water absorbent resin, and a partially neutralized acrylic acid polymer crosslinked product is particularly preferable.

[Care sheet]
Next, the care sheet of the present invention using the water-absorbing composite sheet for care sheet of the present invention as described above will be described.

  2 and 4 are schematic views showing an example of an embodiment of the care sheet according to the present invention, in which (a) is a partially cutaway perspective view, and (b) is B- in FIG. It is an enlarged view of the section which meets a B line. FIG. 3 is a cross-sectional view showing another embodiment of the care sheet of the present invention. In addition, in Fig.2 (a), the below-mentioned ear | edge part of the care sheet has shown the state before bending in J shape.

  The care sheet 10A of FIG. 2 is provided with a tissue 13 on the fixing surface (hereinafter sometimes referred to as “water absorption surface”) of the water absorbent resin sheet 3 of the care sheet of the present invention. The water-permeable sheet 11 is disposed, and the water-impermeable sheet 12 is disposed on the surface opposite to the water-absorbing surface (hereinafter sometimes referred to as “base material surface”) via a tissue 13.

  The care sheet 10B of FIG. 3 has a water-impermeable sheet 12 disposed on the water-absorbing surface side of the water-absorbing composite sheet 1 for care sheet of the present invention via a tissue 13, and the tissue surface 13 on the substrate surface side. A water permeable sheet 11 is arranged.

  2 and 3, the water-permeable sheet 11 and the water-impermeable sheet 12 are folded in a J shape by overlapping the peripheral ear portions 11A and 12A.

  The care sheet 10 </ b> C in FIG. 4 is obtained by disposing a water-impermeable sheet 12 on the water-absorbing surface side of the water-absorbing composite sheet 1 for care sheet of the present invention. The peripheral edge 12B of the water-impermeable sheet 12 is fixed to the base material surface around the base material surface side of the water-absorbing composite sheet 1 for care sheet. In this case as well, a tissue may be provided between the water-impermeable sheet 12 and the water-absorbing composite sheet 1 for a care sheet.

  As described above, the care sheet of the present invention is a single-sided (water-absorbing surface) or double-sided sheet of the water-absorbent composite sheet for care sheet of the present invention with or without a tissue. The non-permeable sheet is arranged on one side with the water absorbing surface of the water absorbent composite sheet for a nursing care sheet facing inside, and is bonded, heat sealed, stitched, or the like. In addition, in FIGS. 2-4, although 1 sheet | seat of the water absorbing composite sheet 1 for care sheets of this invention is used, you may laminate | stack 2 sheets or 3 sheets or more. Further, the water-absorbing composite sheet for a care sheet of the present invention may be cut and inserted into a position where it is desired to be partially absorbed.

  The material of the water-permeable sheet 11 is not particularly limited as long as it has strength and water permeability according to required characteristics, and is as described above as the base material of the water-absorbent composite sheet for care sheet of the present invention. Can be adopted.

On the other hand, the water-impermeable sheet 12 is not particularly limited as long as it can prevent the permeation of the body fluid absorbed by the water-absorbing composite sheet for a care sheet, but polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride. , Thermoplastic resin sheets such as polymethylmethacrylate and polyamide resin, and those having stretchability, for example, styrene elastomer such as styrene-isobutylene block copolymer, styrene-butadiene block copolymer, or ethylene-vinyl acetate copolymer Polyolefin-based elastomers such as coalescence, rubber sheets, and other metal sheets such as aluminum foil can also be used, and the thickness is usually about 10 to 2000 μm and the basis weight is about 10 to 500 g / m ² .

  As shown in FIG. 1, the care sheet of the present invention is a care sheet in which water-absorbent resin particles 3 are fixed to a base material 2 together with the above-described functional substances having antibacterial and deodorizing functions as necessary. In addition to using a water-absorbent composite sheet, the water-permeable sheet itself of the care sheet is used as a base material to which the water-absorbent resin particles are fixed, and the water-absorbent resin particles are directly fixed inside the water-permeable sheet. You can also. That is, the base material to which the water-absorbent resin particles are fixed can be directly molded and used as a water-permeable sheet of a care sheet. In this case, the water-absorbent composite sheet for a care sheet is used as the water-permeable sheet and / or The work process of laminating with a water-impermeable sheet to form a care sheet can be omitted.

  In addition, the care sheet of the present invention can be used after being cut, crushed, pulverized, and compression molded as necessary. Of course, cutting, crushing, and crushing can also be used to recycle non-standard care sheet products. When using by cutting, crushing, and pulverizing, it is preferable that the size is such that it does not easily move in the water-permeable sheet and / or the water-impermeable sheet. Known cutting, crushing, crushing, and compressing equipment can be used for cutting, crushing, crushing, and compressing.

  Further, the care sheet of the present invention includes the above-described water-absorbing composite sheet for the care sheet of the present invention, antibacterial agent, bactericidal agent, bacteriostatic agent, stabilizer for preventing decomposition and alteration of the resin, fragrance and the like. It may contain a functional substance.

(Manufacturing method of care sheet)
Next, although the method of manufacturing the care sheet of this invention is demonstrated, the manufacturing method of the care sheet of this invention is not limited to the following methods at all.

  To manufacture the care sheets 10A and 10B shown in FIGS. 2 and 3, a joining margin is appropriately provided on the peripheral side of the sheets 11 and 12 between the two square water-permeable sheets 11 and the water-impermeable sheet 12. In addition, the laminated sheet of the water-absorbing composite sheet 1 for care sheet of the present invention and the tissue 13 is interposed with an outline smaller than the outline of the both sheets 11 and 12, and then the circumferential side of the both sheets 11 and 12 is inserted. The edge portions (ear portions 11A and 12A) are joined and sealed by an appropriate method such as heat sealing or stitching. More preferably, means for embossing and integrating the water-permeable sheet 11 and the water-impermeable sheet 12 with the water-absorbing composite sheet for care sheet of the present invention interposed therein, or the water-absorbing composite for care sheet of the present invention After water is sprayed on the sheet 1 in advance to slightly swell the water-absorbent resin particles, the water-absorbent resin particles are inserted after being slightly swelled. It is also possible to adopt means for integrating them. However, it is necessary to seal with a sealing pressure that is not damaged by the swelling pressure when the water-absorbing resin swells by absorbing water.

  In order to manufacture the care sheet 10C of FIG. 4, the rectangular sheet of water-impermeable sheet 12 is booked with an outline smaller than the outline of the sheet 12, leaving an appropriate margin on the peripheral side of the sheet 12. The water-absorbing composite sheet 1 for care sheet of the invention is installed with the water-absorbing surface side aligned, and then the peripheral edge 12B of the sheet 12 is folded into the base material surface side of the water-absorbing composite sheet 1 for care sheet, Bonding and sealing are performed by an appropriate method such as sealing, adhesion, and stitching. Even in this case, it is more preferable that the water-impermeable sheet 12 is embossed and integrated, or the water-absorbing composite sheet 1 for the nursing sheet of the present invention is preliminarily lightly sprayed with water in advance. After the water is slightly swollen, a means may be adopted in which the water-absorbent resin particles in a wet state are provisionally integrated with the water-impermeable sheet 12 by applying light pressure. However, it is necessary to seal with a sealing pressure that is not damaged by the swelling pressure when the water-absorbing resin swells by absorbing water.

  In addition, in FIGS. 1-4, although the rectangular thing was shown as the water-absorbing composite sheet for care sheets and the care sheet of the present invention, the water-absorbing composite sheet for care sheets and the care sheet of the present invention are not limited. The shape is not limited to a square shape, and may be a circle, an ellipse, or other irregular shapes depending on the application.

  Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples and Test Examples. The materials, reagents, ratios, operations, and the like shown below can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Example 1>
(Manufacture of water-absorbing composite sheets for nursing care sheets)
A partially neutralized aqueous acrylic acid solution having a monomer concentration of 50% by weight and a neutralization degree of 60 mol% was added to 100 parts by weight of acrylic acid, 133.3 parts by weight of 25% by weight sodium hydroxide aqueous solution and 3.3 parts by weight distilled water. Was prepared. To 100 parts by weight of the partially neutralized acrylic acid aqueous solution, 0.14 parts by weight of N, N′-methylenebisacrylamide as a crosslinking agent and 4.55 parts by weight of a 31% by weight hydrogen peroxide aqueous solution as an oxidizing agent were added. Solution A was prepared.

  Separately, 0.14 parts by weight of N, N′-methylenebisacrylamide as a cross-linking agent and 0.57 parts by weight of L-ascorbic acid as a reducing agent were added to 100 parts by weight of the partially neutralized acrylic acid aqueous solution. Was prepared.

  The prepared solution A and solution B were mixed using the mixing apparatus shown in FIG. In this mixing apparatus, five jet nozzles 21a and 22a are provided at intervals of 1 cm in the monomer solution supply pipes 21 and 22, respectively, and the inner diameters of the nozzles 21a and 22a are 0.13 mm. The intersection angle θ between the solution A and the solution B flowing out from the nozzles 21a and 22a was adjusted to 30 °, and the distance d between the nozzle tips was adjusted to 4 mm. Solution A and solution B were each heated to a temperature of 40 ° C. and supplied with a pump at a flow rate of 5 m / sec (20 ml / min each, total volume 40 ml / min).

The solution A and the solution B merge when they exit the nozzles of the respective nozzle pairs, and after forming the liquid column 23 by about 10 mm each, the droplets 24 become droplets 24 in the gas phase (in air, The temperature dropped to 50 ° C.) and dropped onto a polyethylene terephthalate nonwoven fabric (fineness 7 dtex, basis weight 40 g / m ² ) installed 3 m below the tip of the nozzle (the amount of droplets was 500 g / m ² ). Was completed. After that, it was dried until the water content became 5% to obtain a water absorbent resin composite sheet (50 cm × 50 cm) for a care sheet. The water-absorbent resin particles have a substantially spherical shape with an average particle size of 300 μm (an average value obtained by arbitrarily measuring 50 particles from a micrograph magnified 20 times) and measuring the major axis intermittently with respect to the polyethylene terephthalate nonwoven fabric. The basis weight was 300 g / m ² .

(Manufacture of nursing care sheets)
Place the water-impervious sheet, tissue, manufactured water-absorbing composite sheet for care sheet (with the water-absorbing surface down), tissue, and water-permeable sheet in the order shown in FIG. Was heat-sealed to obtain a care sheet.

Non-water-permeable sheets, tissues, and water-permeable sheets are commercially available care sheets (Unicharm: Lifely Futon Safety Sheet Lot
No. The one extracted from MO319191) was used.

<Example 2>
In Example 1, the same except that a 10% aqueous solution of cetylpyridinium chloride was sprayed and dried on a polyethylene terephthalate resin non-woven fabric in advance so as to give 3 g / m ² of cetylpyridinium chloride monohydrate. The water-absorbing composite sheet for a care sheet was produced by the above operations and methods, and the care sheet was similarly produced using the obtained water-absorbing composite sheet for a care sheet.

<Example 3>
In Example 1, A type zeolite (“Toyo Builder” manufactured by Tosoh Corporation, pore size 4 Å, average particle size 1.5 μm) was previously present on the polyethylene terephthalate resin nonwoven fabric so as to have a basis weight of 100 g / m ^2. A water-absorbing composite sheet for a care sheet was produced by the same operation and method except that it was used, and a care sheet was similarly produced using the obtained water-absorbing composite sheet for a care sheet.

<Comparative Example 1>
In Example 1, a water-absorbing composite sheet for a care sheet was prepared by the same operation and method except that the liquid droplets were dropped onto a polyethylene terephthalate nonwoven fabric placed 0.5 m below the tip of the nozzle and the polymerization was completed. The care sheet was similarly manufactured using the water-absorbing composite sheet for care sheet produced and obtained. In addition, the water-absorbent resin of the obtained water-absorbing composite sheet for a care sheet was not substantially spherical, but was in a state of being connected to each other in the form of a web.

<Comparative example 2>
Heat-bonded fiber nonwoven fabric (polypropylene resin (melting point: 165 ° C.) as a high melting point core component, high density polyethylene (melting point: 130 ° C.) as a low melting point sheath component, fiber: 20 dtex in sheath: core (weight ratio = 1: 1) fiber length 50mm ones intersections of the composite fibers having a crimp of basis weight 100 g / ^{m 2} obtained by thermal bonding) to superabsorbent polymer (San-Dia polymers Ltd.: AQUAPEARL DS50, average particle size 300 [mu] m) Was spread evenly to 300 g / m ^2, and the same heat-bonded fiber non-woven fabric was laminated thereon, and further sandwiched between two heat rolls and thermocompression bonded to produce a plate-shaped care sheet .

<Test example>
The following evaluation was performed about the water-absorbing composite sheet for a nursing sheet and the nursing sheet obtained in each Example and Comparative Example, and the results are shown in Table 1. Note that the blank in the table indicates that no measurement is performed and therefore no data is available.

<Evaluation of water-absorbent composite sheet (care sheet) for care sheet>
(1) Flexibility measurement The water-absorbing composite sheet for care sheet manufactured in Examples 1 to 3 and Comparative Example 1 and the care sheet manufactured in Comparative Example 2 are each manually wound around a tube having an outer diameter of 10 cm. It was confirmed whether or not the whole could be wound, and ○ that could be wound and x that could be folded without being wound. If the flexibility is high, it can be tightly wound around the tube without any problem, but if it is not flexible, it cannot be wound because it is bent or warped.

<Care sheet evaluation>
(1) Water-absorbing resin dropout test Each of the care sheets produced in each example was cut to a size of 15 x 15 cm, placed in a transparent plastic bag, placed on a vibration table, and shaken at 50 Hz and amplitude of 3 mm for 15 minutes. Thereafter, the amount of the water-absorbing resin dropped from the side surface (the cut edge of the care sheet) was measured from the degree of scattering of the water-absorbing swellable substance, and the degree of shedding was determined according to the following formula.

(2) Dryness test Each of the care sheets was placed on a flat surface (in the care sheets of Examples 1 to 3 and Comparative Example 1, the water-impermeable sheet surface was down), the inner diameter was 40 mm, and the outside. An acrylic cylinder with a diameter of 50 mm and a height of 50 mm is placed in the center of this care sheet, and 50 g of adult human urine (mixed with human urine of five adults) is placed in the cylinder, and the time until this is absorbed is stopped. This was taken as the absorption rate (seconds). After 10 minutes, the cylinder was removed, and 20 sheets of filter paper (Toyo Roshi Kaisha, ADVANTEC No. 424, 100 × 100 mm) were placed on top of each other and placed on the filter paper, with a bottom area of 10 cm × 10 cm and 4 kg. A load was applied. After 5 minutes, the load was removed, the weight of the filter paper was measured, and the amount of human urine absorbed by the filter paper was measured to obtain the released amount (g). The above measurement was repeated three times, and the average value was taken as the absorption rate and the release amount.

(3) Antibacterial test Escherichia in sterilized physiological saline
A test solution was prepared by adding E. coli so that the colony forming unit was 1 × 10 ⁷ CFU / ml. A sample (corresponding to 1 g of water-absorbing resin) obtained by cutting each of the care sheets produced in Examples 1 and 2 into 5.8 cm × 5.8 cm was added to 10 ml thereof, and left at 37 ° C. for 24 hours. After 24 hours, a swollen sample was collected, added to 29 ml of sterilized physiological saline, mixed vigorously, and the number of viable bacteria in the supernatant was measured. Similarly Enterobacter
Cloacae, Staphylococcus aureus (Staphylococcus aureus), and Enterococcus faecalis (enterococci) were also tested for antibacterial properties.

(4) Fecal urine deodorization test As urine, human urine was used as a urine component, and chicken feces was crushed as a stool component. First, 5 g of pulverized chicken manure was mixed with 100 g of adult human urine (mixed with human urine of five adults) and allowed to age at room temperature for 3 hours. In a glass container with a lid of 250 ml, put a sample (corresponding to 4 g of water-absorbing resin) obtained by cutting each of the care sheets produced in Examples 1 and 3 into 11.5 cm × 11.5 cm, put 10 g of aged manure, The lid was covered and left in a constant temperature bath at a set temperature of 40 ° C. After standing for 72 hours, the odor density inside the container was measured using a gas-tube detector gas meter.

The malodorous substances measured and the detector tube numbers used are as follows.
Ammonia: Gastec detector tube, 3L
Hydrogen sulfide: Gastec detector tube, 4LT

  From Table 1, the care sheet of the present invention is excellent in water absorption, dryness, and handleability, and also has excellent antibacterial and deodorant properties due to substances having antibacterial and / or deodorant ability. You can see that

Fig.1 (a) is typical sectional drawing which shows an example of embodiment of the water absorptive composite sheet for care sheets of this invention, FIG.1 (b) is the perspective view. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of embodiment of the care sheet | seat of this invention, Comprising: (a) A figure is a partially notched perspective view, (b) figure is an expansion of the cross section in alignment with the BB line of (a) figure. FIG. It is typical sectional drawing which shows an example of another embodiment of the sheet | seat for care of this invention. It is a schematic diagram which shows an example of other embodiment of the care sheet | seat of this invention, Comprising: (a) A figure is a partially cutaway perspective view, (b) A figure is a cross section which follows the BB line of (a) figure. FIG. In an Example, it is a perspective view which shows the mixing apparatus used for manufacture of the water-absorbing composite sheet for care sheets.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water-absorbing composite sheet for care sheet 2 Base material 3 Water-absorbing resin particles 10A, 10B, 10C Care sheet 11 Water-permeable sheet 12 Water-impermeable sheet 21, 22 Piping 21a, 22a Nozzle 23 Liquid column 24 Liquid droplet

Claims (9)

  A water-absorbing composite sheet for a care sheet, comprising: a base material; and substantially spherical water-absorbing resin particles fixed intermittently to the base material.   After the first water-absorbing resin is disposed on the base material, a droplet containing a polymerizable monomer capable of forming the second water-absorbing resin and a polymerized product of the monomer is adhered onto the base material. The first water-absorbing resin is intermittently fixed on the base material by the second water-absorbing resin by polymerizing the monomer and the polymerized polymerization product, and the water-absorbing water for a nursing care sheet Composite sheet.   3. The water absorbing material for a nursing care sheet according to claim 1 or 2, wherein a substance having any of the functions of bacteriostatic, bactericidal, antibacterial, alteration of water absorbing resin, and aroma is supported on the base material. Composite sheet.   4. The water-absorbing composite sheet for a care sheet according to any one of claims 1 to 3, wherein the base material is a water-permeable network structure.   It has the water absorptive composite sheet for care sheets of any one of Claims 1 thru | or 4, and the water-impermeable sheet provided in the water absorptive-resin fixed surface side of this water absorptive composite sheet, Care sheet.   The water-absorbent composite sheet for a care sheet according to any one of claims 1 to 4, and a water-impermeable sheet provided on a surface side opposite to the water-absorbent resin fixing surface of the water-absorbent composite sheet; A care sheet characterized by comprising:   The care sheet according to claim 6, comprising a water-permeable sheet provided on the water-absorbent resin fixing surface side of the water-absorbent composite sheet.   A droplet containing a polymerizable monomer capable of producing a water-absorbing resin and a polymerization product of the monomer is attached to the substrate, and then the monomer and the polymerization product are polymerized to form a substantially spherical shape on the substrate. A method for producing a water-absorbing composite sheet for a nursing care sheet, comprising producing a water-absorbing composite sheet for a nursing care sheet to which the water-absorbing resin particles are intermittently fixed.   After disposing the first water-absorbing resin on the substrate, a droplet containing a polymerizable monomer capable of producing the second water-absorbing resin and a polymerization progress product of the monomer is attached on the substrate to Producing a water-absorbing composite sheet for a care sheet in which the first water-absorbing resin is intermittently fixed onto the base material by the second water-absorbing resin by polymerizing the monomer and the polymerized product. A method for producing a water-absorbent composite sheet for a nursing care sheet.

Images