JPH09239903A - Swelling laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutral swelling sheet having good liquid absorbing power, high wet surface strength, and deodorization effect for an odorous substance. SOLUTION: A surface layer containing fibrous carboxymethyl cellulose which is crosslinked by a multifunctional resin is laminated at least on one side of a liquid absorbing layer containing water absorbing fibers in which a polymer electrolyte complex is formed between at least part of the water soluble salt of fibrous carboxymethyl cellulose and a cationic water soluble polymer by means of paper-making bonding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for sticking rice on the inner surface of a tray for transporting cooked rice for commercial use, or an inner bag for absorbing rice by absorbing rice with condensed water so as to maintain the freshness of condensed fruits and vegetables. A sheet for packaging used to absorb perspiration, a sheet used as a base material for absorbing cosmetic or medicinal HAPs, a sheet used for disposable sanitary products used to wipe off sweat and sebum, and remove ammonia and amine odors, meat and It absorbs juice from foods such as seafood, and a sheet laid inside the food container to reduce ammonia and amine odors, or water is absorbed in advance when the food container is heated in a microwave oven. Water that can be used as a generation source or used for various purposes such as packaging after absorbing moisture for preserving meat and fish, and also as a building material sheet for absorbing dew condensation water It swelled while maintaining the absorption to the original form of, and a sheet having both a deodorizing capability of the ammonia or amine malodor.

[0002]

2. Description of the Related Art Commercially cooked rice, when cooked immediately after being cooked, is placed in a plastic cooking box, sealed and transported, water vapor is condensed to deteriorate the taste. In order to prevent this, a dew condensation water absorption bag in which tissue paper or the like is bundled and put in a breathable nonwoven fabric bag is placed so as to come into contact with cooked rice. In addition, a swellable sheet is also used for packaging in order to absorb condensed water such as fruits and vegetables.

Nonwoven fabrics have been widely used as base materials for cosmetic and medicinal happens, and sanitary sheets for cleaning sweat and sebum, because they are required to have liquid absorbency, tensile strength at swelling and surface strength. . About this sanitary sheet, in order to remove the bad odors such as ammonia emitted with sweat,
A swellable sheet to which a deodorant such as activated carbon or zeolite is added may be used.

Fresh food products are displayed in a film tray pack system in which they are placed on a tray made of a material such as expanded polystyrene and covered with a transparent film. However, the blood juice from meat and fish impairs the appearance, so the sheet form is maintained. As is, a sheet that absorbs moisture is laid between the tray and the food. Further, in order to remove the odor filled in the sealed tray pack, a deodorant such as activated carbon or zeolite is internally added or coated on the sheet.

[0005]

As a swellable sheet suitably used for the above-mentioned applications, a polyelectrolyte complex composed of a cationic water-soluble polymer is formed on at least a part of a fibrous carboxymethyl cellulose salt. A swellable structure is proposed (JP-A-5-106190).
However, since it does not have deodorizing ability by itself, it is necessary to add or coat adsorbent powder such as tea extract or zeolite in order to impart deodorizing ability, but the adsorbent powder does not fall off. Therefore, its use is limited. The present invention provides a neutral swellable sheet having a surface strength when wet while maintaining excellent liquid absorbability comparable to that of the swellable structure, and further having a deodorizing effect of ammonia / amine type malodor. It was designed to be provided.

[0006]

The present invention is described in the above-mentioned Japanese Patent Laid-Open No.
-106190, a liquid absorbing layer formed of a swelling structure as described in No. 106190, at least on one surface, by delamination, by laminating a surface layer for improving the surface strength by papermaking, the above problems can be solved. It is something to solve.
That is, the present invention relates to a liquid-absorbent layer containing a water-absorbent fiber in which a polyelectrolyte complex with a cationic water-soluble polymer is formed on at least a part of a fibrous carboxymethyl cellulose water-soluble salt, and a multi-layer on at least one surface thereof. The present invention relates to a swellable laminated sheet, characterized in that a surface layer containing fibrous carboxymethyl cellulose crosslinked by a functional resin is laminated by sheet-to-paper joining.

In the present invention, the liquid-absorbent layer is characterized in that it contains water-absorbent fibers obtained by forming a polymer electrolyte complex with a cationic water-soluble polymer in at least a part of a fibrous carboxymethylcellulose water-soluble salt. The paper-making fibers and / or fibrous carboxymethylcellulose insoluble salts are blended in the liquid-absorbing layer as needed.
The content of the fibrous carboxymethyl cellulose water-soluble salt in the liquid-absorbent layer is 10% by weight or more, preferably 40% by weight or more, more preferably 60% by weight or more, and the liquid-absorbent layer is composed of only water-absorbent fibers. It may be one.

The fibrous carboxymethylcellulose water-soluble salt which is the base of the water-absorbent fiber is a lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt or ammonium salt of fibrous carboxymethylcellulose.
Alternatively, it is an amine salt such as methylamine or ethanolamine. The degree of etherification of the fibrous carboxymethyl cellulose water-soluble salt is 0.1 to 1.0, preferably 0.3 to
0.8, more preferably 0.4 to 0.6, and the base saturation of the fibrous carboxymethylcellulose water-soluble salt (ratio of carboxyl groups into salt) is 50 to 1
00%, preferably 80 to 100%, more preferably 9
0 to 95%.

The cation-type water-soluble polymer for forming a polyelectrolyte complex on the above-mentioned fibrous carboxymethyl cellulose water-soluble salt is a polymer compound having a basic group in the molecule and is a primary, secondary, or tertiary polymer. It is a water-soluble polymer composed of a repeating unit having at least one selected from primary and quaternary nitrogen atoms. An example of such a cationic water-soluble polymer is the natural polymer compound chitosan,
The synthetic polymer includes a polymer (1) having a primary, secondary, tertiary or quaternary nitrogen atom in the side chain of the polymer and primary, secondary, tertiary or quaternary in the main chain of the polymer. There is a polymer (2) having a nitrogen atom.

One example of the polymer (1) having a primary, secondary, tertiary or quaternary nitrogen atom in the side chain of the polymer is (1-a) primary, secondary, tertiary or quaternary. It is a homopolymer of a monomer having a primary nitrogen atom and a polymerizable group such as a vinyl group in addition thereto, that is, a homopolymer of the following monomers. N, N-dialkylvinylamine, vinyltrialkylammonium, N-alkylaminoalkylacrylate, N-alkylaminoalkylmethacrylate, N-alkylaminoalkylacrylamide,
N-alkylaminoalkylmethacrylamide, N,
N-dialkylaminoalkyl acrylate, N, N-
Dialkylaminoalkyl methacrylate, N, N-
Dialkylaminoalkylacrylamide, N, N-dialkylaminoalkylmethacrylamide, acryloyloxyalkyltrialkylammonium, methacryloyloxyalkyltrialkylammonium, acrylamidoalkyltrialkylammonium, methacrylamidoalkyltrialkylammonium, vinyloxyalkylamine, N-alkyl Monomers such as vinyloxyalkylamine, N, N-dialkylvinyloxyalkylamine, N, N, N-trialkylvinyloxyalkylammonium. In these monomers, the alkyl group has 1 to 4 carbon atoms, and an alkanol group may be introduced instead of the alkyl group, and instead of one alkyl group bonded to the nitrogen atom of the quaternary ammonium salt. An alkoxycarbonylalkylene group may be introduced. A specific example of a homopolymer of the above monomers is poly (methacryloyloxyethyltrimethylammonium chloride).

Another example of the polymer (1) having a primary, secondary, tertiary or quaternary nitrogen atom in the side chain of the polymer is (1-b) primary, secondary, tertiary or quaternary. It is a copolymer of a monomer having a primary nitrogen atom and another polymerizable group, and another monomer, that is, a copolymer of the monomer described in (1-a) above and another monomer. Other monomers include acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, alkyl acrylate, alkyl methacrylate, vinyl acetate, styrene,
Examples include α-methylstyrene, 4-vinylpyridine, and 2-vinylpyridine. A specific example of the copolymer is poly (3-acrylamido-3-methylbutyltrimethylammonium chloride-CO-acrylamide).

As another example of the polymer (1) having a primary, secondary, tertiary or quaternary nitrogen atom in the side chain of the polymer, (1-c) a homopolymer such as polyacrylamide is modified with Mannich. Alternatively, it is cationized by a Hoffmann decomposition reaction.

The polymer (2) having a primary, secondary, tertiary or quaternary nitrogen atom in the main chain of the polymer is (2)
There are (a) ionene polymer, (2-b) polyethyleneimine, (2-c) polyamine resin in a narrow sense, and (2-d) other condensation polymers.

The (2-a) ionene polymer is a polymer having an ionic amino group, in particular, a quaternary ammonium group in its main chain, and most of the nitrogen atoms are quaternized. 2-a-i) a polyaddition product of a dihalo compound having a halogen atom at both ends of the molecule and a ditertiary amine having a tertiary nitrogen atom at both ends of the molecule, (2-a-ii) epichloro in 1 mol of a primary amine Polymerizable precursor produced by ring-opening addition of 2 moles of hydrin (3rd group having chlorine groups at both ends of the molecule)
Amine) and a polyaddition product of a ditertiary amine having a tertiary nitrogen atom at both ends of the molecule, (2-a-iii) 1 mol of epichlorohydrin is ring-opened and added to 1 mol of the secondary amine. ,
For example, a polymer obtained by polyadding a compound having a chlorine atom on one molecular end and a tertiary nitrogen atom on the other molecular end.

(2-b) Polyethyleneimine is a polymer produced by ring-opening polymerization of ethyleneimine,
The main chain branched from the main chain has primary, secondary, and tertiary nitrogen atoms.

The academic definition of the (2-c) polyamine resin has not been established, but in a narrow sense, for example, primary, secondary, and tertiary.
Containing quaternary and quaternary nitrogen atoms is defined as having less than half of the total number of nitrogen atoms in the quaternized nitrogen atom, and is distinguished from the ionene polymer in that the number of quaternized nitrogen atoms is small. Examples include: (2-ci) Polymer obtained by polycondensing a compound obtained by ring-opening addition of 1 mol of epichlorohydrin to 1 mol of primary amine while suppressing generation of quaternary nitrogen atom.
Is a polyamine resin and its hydrochloride, (2-c-
ii) A polyamine resin which is a polycondensate of alkylenediamine and epichlorohydrin, and a polyamine resin which is a polycondensate of (2-c-iii) alkylenediamine and alkylenedihalide.

(2-d) Other condensation polymers include (2-d-i) polyamine polyamide which is a polycondensation product of alkylene polyamine and dicarboxylic acid, for example, polycondensation product of diethylene triamine and adipic acid, (2- d
-Ii) When epichlorohydrin and dimethylamine are further added to this polyamine polyamide, the chlorine group of epichlorohydrin is added to the amide group of polyamine polyamide to be quaternized, and epichlorohydrin is opened to dimethylamine. Cycloaddition results in a polymer having secondary, tertiary and quaternary nitrogen atoms in the main chain and tertiary nitrogen atoms in the side chains.

Further, in the above chitosan, homopolymers, copolymers, modified products and the like, a polymer obtained by quaternizing a primary, secondary or tertiary nitrogen atom with a quaternizing agent is also a cationic water-soluble polymer. Is. The quaternizing agent is capable of introducing an alkyl group or an alkoxycarbonylalkylene group into a primary, secondary or tertiary nitrogen atom, and is a halogenated alkyl such as methyl chloride, ethyl chloride or methyl bromide, dimethylsulfate or chloro. Such as methyl acetate. The quaternization reaction may be carried out after the repeating unit is a monomer and then polymerized, or after polymerization, the repeating unit in the polymer may be quaternized by a polymer reaction.

The above-mentioned cationic water-soluble polymers are primary, 2
Other than primary, tertiary or quaternary nitrogen atoms, highly reactive functional groups that form crosslinks, such as glycidyl groups, aldehyde groups, carboxyl groups, vinyl groups, allyl groups, N-methylol groups, thiol groups, isocyanates. , Isothiocyanate, etc. are not substantially contained. This is to prevent the cationic water-soluble polymer from forming covalent crosslinks and the like other than forming a polyelectrolyte complex in the fibrous carboxymethylcellulose water-soluble salt. By substantially free is meant that covalent crosslinks are not included to the extent that they do not inhibit or reduce the formation of polyelectrolyte complexes.

The cationic water-soluble polymer has a cation equivalent of 0.1 to 20 meq / g, preferably 1 to 15 meq / g, and more preferably 2 to 10 meg in the range of pH 3-9. Equivalent weight / g, (number) average molecular weight is 5,000 to 100,000, preferably 5,000 to 7
0000, and more preferably 5000 to 20000.

The amount of the cationic water-soluble polymer added to the fibrous carboxymethylcellulose water-soluble salt is within the range of 0.1 to 100% of the anion equivalent of the fibrous carboxymethylcellulose water-soluble salt. An appropriate amount is selected according to the kind of the cationic water-soluble polymer. A polyelectrolyte complex is formed in the fibrous carboxymethyl cellulose water-soluble salt by adding an amount of the cationic water-soluble polymer in this range. The polyelectrolyte complex is a complex that is considered to be formed mainly through Coulomb force between a fibrous carboxymethylcellulose water-soluble salt having an opposite charge and a cationic water-soluble polymer. The details of the structure are not clear, but the cation-type water-soluble polymer is ionically cross-linked between the molecules of the fibrous carboxymethylcellulose water-soluble salt, or the cation-type water-soluble polymer is added to the molecular chain of the fibrous carboxymethylcellulose water-soluble salt. It is conceivable that the structures are close together.
The fibrous carboxymethylcellulose water-soluble salt, which is in the form of an amorphous gel by partially dissolving and partially swelling in water due to the formation of the polyelectrolyte complex, swells while maintaining the fiber form and becomes a fibrous gel. Therefore, it is possible to obtain a water-absorbent fiber having a certain degree of wet strength and liquid absorbency due to the manifestation of the fiber form.

In the present invention, it is preferable to add papermaking fibers to the liquid-absorbent layer in addition to the water-absorbent fibers in order to improve paper-making properties, wet strength, and cost.

The fibers for papermaking include wood pulp, non-wood pulp, dissolving pulp, plant pulp such as refined cellulose short fiber ("Lyocell" manufactured by Courtles of England), semi-synthetic fiber for papermaking such as rayon, polyethylene. Synthetic fiber for papermaking consisting of polypropylene, polyester, acrylic, vinylon, polyvinyl alcohol, activated carbon fiber, etc. for papermaking, ethylene vinyl acetate copolymer and polypropylene, polyethylene and polypropylene, low softening point polyester and polyester As a result of these additions, the paper-making property and the wet strength are improved although the water absorption capacity is slightly lowered by the blending.

Another example of the paper-making fiber to be mixed in the liquid-absorbent layer is a latent crimpable parallel type composite fiber in which two or more kinds of thermoplastic resins having different melting points are laminated in parallel to the fiber axis direction. This synthetic fiber has the function of forming a coiled micro crimp by heating in a temperature range between the softening points of two or more types of thermoplastic resins, and forming a crimpable side-by-side composite fiber. After that, by performing a heat treatment under a non-pressurized condition such as hot air heating, the sheet becomes bulky and porous, and has an effect of enhancing water absorption.

In order to obtain the effect of blending the papermaking fibers in the liquid absorbing layer, it is desirable to blend 10% by weight or more of the papermaking fibers. On the other hand, in order to prevent the water absorbing ability of the water absorbing fibers from decreasing, 90 Weight% or less, desirably 60
The content is preferably not more than 20% by weight, more preferably 20 to 60% by weight in the case of latently crimpable parallel conjugate fibers and 20 to 40% by weight in the case of other papermaking fibers.

The liquid-absorbent layer also contains aluminum salt, iron salt,
Copper salt, cobalt salt, zinc salt, tin salt, lead salt, barium salt,
A fibrous carboxymethyl cellulose insoluble salt such as a manganese salt can be added. These fibrous carboxymethyl cellulose insoluble salts have a deodorizing effect on malodorous substances. The fibrous carboxymethylcellulose insoluble salt has a base saturation (ratio of carboxyl groups that become a salt) of 2 to 50%, preferably 10 to 40%, and more preferably 20 to 30%.

The blending amount of the fibrous carboxymethylcellulose insoluble salt in the liquid-absorbent layer varies depending on the base saturation of the fibrous carboxymethylcellulose insoluble salt, and the one having a high base saturation decreases the papermaking property. There must be. 80% by weight or less when the base saturation is less than 2% to 10%, and the base saturation is 10% to 20%
If less than 60% by weight, base saturation is 20% to 30
% Or less, 40% by weight or less, base saturation is 30% to 5
When it is less than 0%, it is 20% by weight or less.

The fibrous carboxymethylcellulose insoluble salt has a high reactivity with ammonia and an amine-based malodorous substance and has a strong deodorizing action, but since some salts contain heavy metal salts, it is necessary to select the type of salt depending on the application. Aluminum salts or iron salts can be widely used for foods, cosmetics, sundries, building materials and the like.

Copper salts, zinc salts, tin salts, lead salts, barium salts and the like are added to deodorize ammonia and amine malodorous substances,
Although it has the effect of deodorizing sulfur malodorous substances, it is not suitable for food. In the case of zinc salt, it can be used for cosmetics other than food, miscellaneous goods, building materials, etc., but in the case of other salts,
Limited to applications such as sundries or building materials.

In addition to the above, the liquid absorbing layer may also include
A starch-based or polyacrylamide-based paper strength enhancer, a wetting agent such as sucrose fatty acid ester, and a white or colored filler or pigment usually used for papermaking can be added.

The liquid absorbing layer composed of the above components is
Thus, the water-absorbent fiber formed by forming a polyelectrolyte complex with a cationic water-soluble polymer in at least a part of the fibrous carboxymethyl cellulose water-soluble salt, has a high water-absorption capacity in the state of maintaining the sheet form, papermaking When the fibers for use are blended, the water absorption capacity is slightly lowered, but the wet strength and paper formability are further improved. The basis weight of the liquid-absorbent layer is not particularly limited, and a single-layer sheet can be used to make a single-layer sheet.
By making a plurality of wet papers with a paper net having more than one base and making them together, it is possible to make an absorbent layer having a large basis weight. Further, in this case, for each layer constituting the liquid absorbing layer,
It is also possible to change the compounding ratio of the water absorbent fiber and the papermaking fiber.

The present invention is characterized in that a surface layer containing fibrous carboxymethyl cellulose (CMC-H) cross-linked with a polyfunctional resin is laminated on at least one surface of the liquid-absorbing layer by laminating and bonding. To do. If necessary, a fibrous carboxymethylcellulose insoluble salt and / or a papermaking fiber is blended in the surface layer. Fibrous carboxymethyl cellulose in the surface layer (CMC-
The amount of H) is 5% by weight or more, preferably 20% by weight.
As described above, more preferably 60% by weight or more, and the surface layer may be composed only of fibrous carboxymethyl cellulose.

The fibrous carboxymethyl cellulose (CMC-H) used for the surface layer is a free acid type of carboxymethyl group, and the degree of etherification is 0.1 to 1.
0, preferably 0.3 to 0.8, more preferably 0.4
０．６0.6. Since fibrous carboxymethyl cellulose has a free acid type carboxymethyl group, it is insoluble in water and does not gel, but it is highly hydrophilic due to the presence of the carboxymethyl group, and the amount of water penetrating into the fiber is also high. The amount is higher than that of plant pulp, and the reactivity with the polyfunctional resin is high and a cross-linking bond is formed to easily obtain high wet strength and high surface strength. Further, it reacts with ammonia and amine-based malodorous substances, and these malodorous substances can be removed from the atmosphere in the form of fibrous carboxymethylcellulose ammonia salt or amine salt. Therefore, the fibrous carboxymethyl cellulose can function as a fibrous deodorant against malodors of ammonia and amines.

In the surface layer, the polyfunctional resin used for crosslinking the fibrous carboxymethyl cellulose is, for example, polyamide epichlorohydrin resin, melamine resin, urea resin, etc., but melamine resin and urea resin generate formalin. Therefore, the polyamide epichlorohydrin is preferably used only in applications other than foods, and is desirable from the viewpoint of strengthening cross-linking.

In addition to the above fibrous carboxymethyl cellulose, the surface layer is insoluble in fibrous carboxymethyl cellulose such as aluminum salt, iron salt, copper salt, cobalt salt, zinc salt, tin salt, lead salt, barium salt, manganese salt and the like. A salt can be added to improve the deodorizing effect. The fibrous carboxymethyl cellulose insoluble salt has a base saturation of 2 to 50 (ratio of carboxyl groups to be salt).
%, Preferably 10-40%, more preferably 20-3
0%.

The amount of the fibrous carboxymethylcellulose insoluble salt compounded in the surface layer depends on the base saturation of the fibrous carboxymethylcellulose insoluble salt, as in the case of the liquid absorbing layer. If the fibrous carboxymethylcellulose insoluble salt has a high base saturation, the papermaking property is deteriorated. Therefore, the blending amount must be reduced.
80% by weight or less when the base saturation is 2% to less than 10%,
60% by weight or less when the base saturation is 10% to less than 20%, 40% by weight when the base saturation is 20% to less than 30%
Hereinafter, when the base saturation is 30% to less than 50%, it is 20% by weight or less.

The fibrous carboxymethylcellulose insoluble salt has a higher reactivity with ammonia and an amine malodorous substance than the fibrous carboxymethylcellulose and has a strong deodorizing effect, but since some salts contain a heavy metal salt, the type of salt depends on the application. Must be selected. Aluminum salts or iron salts can be widely used for foods, cosmetics, sundries, building materials and the like. Further, in the case of iron salt, it also has the effect of imparting water repellency to the surface layer, and a surface layer having excellent water resistance can be formed.

Copper salts, zinc salts, tin salts, lead salts, barium salts, etc. are added to deodorize ammonia and amine malodorous substances,
Although it has the effect of deodorizing sulfur malodorous substances, it is not suitable for food. In the case of zinc salt, it can be used for cosmetics other than food, miscellaneous goods, building materials, etc., but in the case of other salts,
Limited to applications such as sundries or building materials.

The fibrous carboxymethylcellulose insoluble salt may be blended in the liquid absorbing layer, and in this case, the fibrous carboxymethylcellulose insoluble salt in the liquid absorbing layer also has a deodorizing effect.

The fibrous carboxymethyl cellulose insoluble salt is also cross-linked by a polyfunctional resin such as a polyamide epichlorohydrin resin, a melamine resin and a urea resin, like the fibrous carboxymethyl cellulose. Desirable as the polyfunctional resin is polyamide epichlorohydrin as described above.

Thus, the fibrous carboxymethyl cellulose or the fibrous carboxymethyl cellulose and the fibrous carboxymethyl cellulose insoluble salt are crosslinked between the fibers by the polyfunctional resin, and exhibit high tensile strength and surface strength in a wet state. And ammonia,
Exhibits a deodorizing effect on amine odors.

The surface layer in the present invention is further improved in order to improve paper-making property, wet strength, water absorption, and cost reduction.
It is desirable to incorporate papermaking fibers.

The fibers for papermaking include wood pulp, non-wood pulp, dissolving pulp, plant pulp such as purified cellulose short fiber ("Lyocell" manufactured by Courtles of England), semi-synthetic fiber for papermaking such as rayon, polyethylene. Synthetic fiber for papermaking consisting of polypropylene, polyester, acrylic, vinylon, polyvinyl alcohol, activated carbon fiber, etc. for papermaking, ethylene vinyl acetate copolymer and polypropylene, polyethylene and polypropylene, low softening point polyester and polyester ,
Examples of the latent crimpable parallel type conjugate fiber include two or more kinds of thermoplastic resins.

When plant pulp or semi-synthetic fiber is blended as the papermaking fiber, the hydrophilicity of the surface layer is not significantly reduced,
In order to develop wet strength, it is necessary to crosslink these with a polyfunctional resin. In this case, the polyfunctional resin is required to be uniformly fixed to both the fibrous carboxymethyl cellulose, and the fibrous carboxymethyl cellulose insoluble salt and the papermaking fiber that are blended as necessary, and therefore, in the mixed dispersion liquid of these. It is desirable to add.

The kind and blending ratio of the papermaking fibers blended in the surface layer are determined by the target surface strength and tensile strength in a wet state and the degree of water absorption and hydrophilicity imparted to the surface layer. In order to obtain the effect of blending papermaking fibers in the surface layer, it is desirable to blend 10% by weight or more of papermaking fibers, but the upper limit of blending varies depending on the type of papermaking fibers and is as follows.

In the case of plant pulp or semi-synthetic fiber, the compounding ratio is 95% by weight or less, preferably 50% by weight or less, more preferably 30% by weight or less.

When the synthetic fibers for papermaking and the composite type synthetic fibers for papermaking are blended, the wet strength is further improved by fusing the synthetic fibers with each other. However, if the blending ratio of these is increased, the hydrophilicity of the surface layer is improved. Since the amount of water absorption decreases, the compounding ratio in the surface layer is 80% by weight or less, preferably 60% by weight or less, and more preferably 40% by weight or less.

The latent crimpable parallel type conjugate fiber is blended, formed into a sheet, and then subjected to non-contact heating to heat-bond the fibers to each other and to develop a coiled microcrimp structure, and thus the crimpable parallel type conjugate fiber. When converted into, the sheet becomes bulky and porous to improve the water absorption amount, but if the blending rate increases, the hydrophilicity of the surface layer decreases and the water absorbing rate slows, so the blending rate in the surface layer is 60% by weight or less. , Preferably 40% by weight
Hereafter, it is more preferably 25% by weight or less.

In addition to the above, the surface layer may be, if necessary,
Wetting agents such as starch-based, polyacrylamide-based paper strengthening agents, and sucrose fatty acid esters can be added. It is possible to add white or colored powders that are usually used for papermaking, but in the case of internal addition, when a coagulation / fixing agent is added together with the powder and the sheet becomes rewet due to water absorption. ,
The powder must be prevented from falling off. As the aggregating / fixing agent, polymer-based aggregating / fixing agents such as polyacrylamides, sodium polyacrylates, polyethylene glycols, etc., inorganic agglomerates such as aluminum sulfate, aluminum chloride, ferric chloride, ferric sulfate -Natural polymer-based aggregating / fixing agents such as fixing agents, cationic starch, chitosan and the like can be used.

The surface layer composed of the above components is
Thus, the fibrous carboxymethyl cellulose cross-linked with the polyfunctional resin is rich in hydrophilicity, has high water absorption, exhibits high tensile strength and surface strength in a wet state, and has a deodorizing effect on ammonia and amine odors. Exert. Furthermore, when a fibrous carboxymethyl cellulose insoluble salt is blended, the deodorizing effect is further large, and when a papermaking fiber is blended, water absorption, hydrophilicity, wet strength are reinforced, and papermaking properties are improved. It has the characteristic of improving.

The surface layer is required to reinforce the low wet surface strength of the liquid-absorbent layer and increase the wet strength of the entire laminated sheet. Therefore, the basis weight is 5 to 30 g / m ² , preferably 10 to 2
0 g / m ² . If the basis weight is lower than 5 g / m ² , the wet strength is not sufficiently imparted, and if it exceeds 30 g / m ² , the surface layer occupies a large proportion of the entire laminated sheet, and the water absorption amount of the laminated sheet decreases, which is not preferable.

The laminated sheet has a two-layer structure in which one surface of the liquid-absorbing layer is joined to one surface of the liquid-absorbing layer, and one surface of the liquid-absorbing layer is formed on both surfaces of the liquid-absorbing layer. In addition to the three-layer structure in which the paper is joined and bonded together, a plurality of liquid-absorbing layers having different paper-making fibers and the like mixed in the liquid-absorbing layer, for example, 2, 3, 4, 5
It is possible to have a multi-layer structure in which layers are laminated and a surface layer is laminated and bonded on one side or both sides thereof.

To produce the swellable laminated sheet according to the present invention, at least a fibrous carboxymethylcellulose water-soluble salt is added by adding a cationic water-soluble polymer to a dispersion liquid of the fibrous carboxymethylcellulose water-soluble salt. A water-absorbent fiber having a partly formed polyelectrolyte complex is prepared, and if necessary, a paper-making fiber and / or a fibrous carboxymethyl cellulose insoluble salt is added to the raw material to make a paper. Create layer wet paper.
Further, a dispersion of fibrous carboxymethyl cellulose or a dispersion of fibrous carboxymethyl cellulose and a fibrous carboxymethyl cellulose insoluble salt is mixed with a polyfunctional resin for cross-linking and optionally a papermaking fiber to prepare a papermaking raw material. The paper is made into a surface layer wet paper. Combine wet paper for liquid absorption layer and wet paper for surface layer 2
A wet paper of three layers, and a method of heating and drying the wet paper, or a three-layer wet paper by combining the liquid absorbent wet paper into the intermediate layer and the surface wet paper as both outer layers, The wet paper web can be produced by heating and drying. For the papermaking of wet paper, the papermaking method usually used in the papermaking technology described in JP-A-4-37536 can be used.

When a fibrous carboxymethylcellulose insoluble salt is blended in the liquid-absorbing layer and the surface layer, a fibrous carboxymethylcellulose insoluble salt may be added to the papermaking raw material in advance to prepare a paper. After the papermaking raw material added with papermaking and drying,
A method of forming a fibrous carboxymethylcellulose insoluble salt in a sheet by impregnating with an aqueous solution of a water-soluble aluminum salt, iron salt, copper salt, cobalt salt, zinc salt, tin salt, lead salt, barium salt, manganese salt, etc. It can also be used.

As a papermaking fiber for the liquid absorbing layer or the surface layer,
In the case of producing a sheet containing crimpable parallel type composite fibers, after mixing latent latent crimpable parallel type composite fibers into a papermaking raw material to make a paper, a heat radiation type tunnel heat treatment machine or It is necessary to heat the heat treatment temperature at 130 ° C. or higher for 1 second or longer using a hot-air dryer so that the latent crimpable parallel type conjugate fiber exhibits crimps.

[0056]

EXAMPLES Examples of the swellable laminated sheet according to the present invention are shown below. In each example, the swellable laminated sheet structure has a water absorption amount, a wet tensile strength, a surface strength in a wet state, and a wet state. The slime and deodorizing ability in the above were evaluated as follows.

<Water absorption> A test piece of 10 cm x 12 cm was immersed in 1000 ml of tap water for 15 minutes and then pulled up.
The test piece was weighed by hanging it with one end facing up for 1 minute to drop excess water. The water absorption amount was calculated by the following formula. Water absorption (g / g) = [(weight of test piece after removal of excess water g)
-(Test piece air dry weight g)] ÷ (Test piece air dry weight g)

<Wet tensile strength> Width 15 mm, length 2
After immersing a 00 mm test piece in tap water at 20 ° C. for 30 minutes, excess water was wiped with a filter paper, and the tensile strength was measured with a Shopper-type tensile tester.

<Surface Strength in Wet State> 10 cm × 10
On the surface of the central part of the cm test piece, 5 drops of water were dropped with a 3 ml volume syringe, and after the water had penetrated into the paper, 30
The degree of surface breakage and fuzzing when rubbed back and forth was observed and evaluated on a five-point scale. The surface strength 1 indicates a state in which tearing occurs and fluffing is extremely large, the surface strength 3 indicates a state in which fluffing slightly occurs, and the surface strength 5 indicates a state in which tearing or fluffing hardly occurs.

<Nulliness in a wet state> 10 cm × 12 c
The test piece of m was immersed in 1000 ml of tap water for 3 minutes and then pulled up, and the feel of the surface of the test piece was sensory evaluated.

<Ammonia deodorizing ability> 15 cm × 20 c
The test piece of m was placed in an Erlenmeyer flask with a capacity of 300 ml and tightly sealed with a silicon rubber stopper with a gas inlet, and ammonia standard gas was injected from the gas inlet with a gas tight syringe to set the initial gas concentration in the Erlenmeyer flask to 140,000 PPM. did. One hour later, a gas detection tube manufactured by Gastec Co., Ltd. was inserted into the Erlenmeyer flask through the gas inlet, the gas concentration (PPM) in the Erlenmeyer flask was measured, and the deodorization rate was calculated from the following formula. Ammonia deodorization rate (%) = 100-Gas detector tube quantitative concentration ÷
Ammonia gas initial concentration x 100

<Trimethylamine deodorizing ability> 15 cm ×
A 20 cm test piece was placed in an Erlenmeyer flask with a capacity of 300 ml and sealed with a silicone rubber stopper with a gas inlet, and trimethylamine standard gas was injected from the gas inlet with a gas tight syringe to set the initial gas concentration in the Erlenmeyer flask to 150 P.
PM. One hour later, a gas detection tube manufactured by Gastec Co., Ltd. was inserted into the Erlenmeyer flask through the gas inlet, the gas concentration (PPM) in the Erlenmeyer flask was measured, and the deodorization rate was calculated from the following formula. Trimethylamine deodorization rate (%) = 100-Gas detector tube quantitative concentration / Trimethylamine gas initial concentration x 100

Examples 1 to 9 Fibrous carboxymethyl cellulose Na salt (CMC-Na salt) (manufactured by Nichirin Kagaku Co., Ltd., etherification degree 0.43, base saturation 82%)
Was dispersed in water to prepare a dispersion having a concentration of 1.5%. Polyamine resin (Sumitomo Chemical Co., Ltd., trade name Sumirez resin FR-2P, number average molecular weight 100)
00, cation equivalent at pH 6 is 5.8 meq / g, 4
2.0% by weight based on the fibrous carboxymethyl cellulose Na salt)
Of water-absorbent fiber obtained by adding and stirring at a ratio of 5% and various paper-making fibers as shown in the column of paper-making fiber of the liquid-absorbent layer in Tables 1 and 2 are blended in respective predetermined parts by weight. A raw material for papermaking was prepared to prepare a wet absorbent paper having a basis weight of 55 g / m ² .

Separately, fibrous carboxymethyl cellulose (CMC-H) (manufactured by Nichirin Kagaku Co., Ltd., degree of etherification 0.43, degree of base saturation 0%, free acid type) and columns of surface layer in Table 1 and Table 2. Prepare a mixed fiber raw material prepared by blending predetermined parts by weight of various papermaking fibers in water as shown in, and add 8 parts by weight of polyamide epichlorohydrin resin (product name WS570 manufactured by Japan PMC) to the mixed fiber raw material. %
Is added at a ratio of 1 to prepare the raw material for paper making of the surface layer, and the basis weight is 1
A surface layer wet paper of 5 g / m ² was prepared.

The wet paper web of the liquid absorbing layer is used as an intermediate layer, and the wet paper web of the surface layer is superposed on both surfaces of the wet paper web.
After pressurizing at ² for 5 minutes, it was dried by bringing it into contact with a heating mirror plate of a rotary dryer, and 9 types of three-layer papermaking type handmade shown in Tables 1 and 2 as Examples 1-9. Paper was made.

The obtained handmade papers (Examples 1 to 9) were evaluated for water absorption, wet tensile strength, surface strength in a wet state, slime in a wet state, and deodorizing ability, and the results are shown in Table 1. , Shown in Table 2. For comparison, the evaluation results of the single-layer handmade paper having a basis weight of 85 g / m ² produced by using the paper-making raw material for the liquid-absorbent layer of Example 1 are also shown in Table 2 as a comparative example.

From Tables 1 and 2, the water absorption of the three-layer laminating type handmade papers of Examples 1 to 9 is their own weight (basis weight is 85 g / gram).
m ² ), which is more than 4 times the m ² ), and shows the same amount of water absorption as the single-layer handmade paper of the comparative example, while the wet tensile strength is 2 to 8 times higher than that of the comparative example. Regarding the wet surface strength, in Examples 1 to 9, tearing and fluffing were extremely small, and the surface strength was higher than that in Comparative Example. Furthermore, Examples 1-9
Has a deodorizing rate of 98% or more for the ammonia / amine type malodor, and it is clear that it has an excellent deodorizing effect.

Examples 10 to 12 Fibrous carboxymethyl cellulose Na salt (manufactured by Nichirin Kagaku Co., Ltd., degree of etherification 0.43, degree of base saturation 82%) was dispersed in water to a concentration of 1.5%. The prepared dispersion liquid was prepared. A water-absorbent fiber obtained by adding a cationic water-soluble polymer to the fibrous carboxymethyl cellulose Na salt at a ratio of 2.0% by weight and stirring the mixture, and a latent crimping side-by-side composite fiber, respectively. As shown in Table 3, a predetermined amount by weight was compounded to prepare a raw material for paper making of the liquid absorbing layer to prepare a wet paper for liquid absorbing layer having a basis weight of 55 g / m ² .

As the above-mentioned cation-type water-soluble polymer, Example 10 is a polyamine resin (Sumitomo Chemical Co., Ltd. Sumirez resin FR-2P, number average molecular weight 10000, cation equivalent is 5.8 meq / pH 6). g, containing a quaternized nitrogen atom and a tertiary nitrogen atom). Example 11
Is chitosan (Katakura Chikkarin Co., Ltd. primary, secondary nitrogen atom-containing, cation equivalent 4.2 meq / g), and dissolved in lactic acid aqueous solution so that chitosan concentration becomes 2.5%. The fibrous carboxymethyl cellulose Na
Added to salt. In Example 12, a cation type polyacrylamide resin (manufactured by Meisei Chemical Industry Co., Ltd., trade name AG Fix M15, cation equivalent 4.5 meq / g, containing quaternized nitrogen atom) was used.

Separately, fibrous carboxymethyl cellulose (CMC-H) (manufactured by Nichirin Kagaku Co., Ltd., degree of etherification 0.43, degree of base saturation 0%, free acid type) and the surface layer of Table 3 are shown. Prepare a mixed fiber raw material prepared by mixing various parts of various papermaking fibers in water and dispersing it in water, and add a polyamide epichlorohydrin resin (trade name W manufactured by Japan PMC Co., Ltd.
S570) was added at a ratio of 8% by weight to the mixed fiber raw material to prepare the papermaking raw material for the surface layer, and the basis weight was 15 g / m ^2.
A surface layer wet paper of was prepared.

The wet paper of the liquid absorbing layer was used as an intermediate layer, and the wet paper of the surface layer was superposed on both surfaces of the wet paper, and 3.5 Kg / cm was passed through a filter paper for water squeezing.
After pressurizing at ² for 5 minutes, it was brought into contact with a heating mirror plate of a rotary dryer to be dried, and three kinds of three-layer paper making type handmade papers shown in Table 3 as Examples 10 to 12 were produced. did.
Then, the handmade paper is left in a hot air dryer at 160 ° C. for 30 seconds to be heat-treated to develop crimps in the latently crimpable side-by-side composite fibers, thereby making the sheet bulky and low in density. .

With respect to the obtained handmade papers (Examples 10 to 12), the water absorption, the wet tensile strength, the surface strength in the wet state, the slime in the wet state, and the deodorizing ability were evaluated, and the results are shown in Table 3. It was shown to.

The three-layer laminated handmade papers of Examples 10 to 12 have a water absorption of 4 times or more of their own weight, and show the same water absorption as the single-layer handmade paper of the comparative example. The wet tensile strength is 2-3 times higher than that of the comparative example. Regarding the wet surface strength, in Examples 10 to 12, breakage and fluffing were extremely small, and the surface strength was higher than that in Comparative Example. Further, Examples 10 to 12 have a deodorizing rate of ammonia / amine malodor of 98% or more, and it is clear that they have an excellent deodorizing effect.

Example 13 Fibrous carboxymethylcellulose Na salt (manufactured by Nichirin Kagaku Co., Ltd., degree of etherification 0.43, degree of base saturation 82%) was dispersed in water to give 1.
A dispersion having a concentration of 5% was prepared.

A secondary amine-epichlorohydrin polyaddition polymer synthesized from dimethylamine and epichlorohydrin as a cationic water-soluble polymer (average molecular weight 8
900, cation equivalent 6.2 meq / g) was added to the fibrous carboxymethyl cellulose Na salt at a ratio of 2.0% by weight and stirred to obtain 70% by weight of water-absorbent fiber, and fiber for papermaking. 20% by weight of bleached softwood kraft pulp and 10% by weight of CMC-Zn salt which is a fibrous carboxymethylcellulose insoluble salt are blended to prepare a papermaking raw material for a liquid absorbing layer, and a grammage of 55 g / m ² is absorbed. A liquid layer wet paper was prepared.

Separately, 70% by weight of fibrous carboxymethyl cellulose (CMC-H) (manufactured by Nichirin Chemical Co., Ltd., degree of etherification 0.43, degree of base saturation 0%, free acid type) and 20% softwood kraft pulp were added. %, And 10% by weight of CMC-Al salt, which is a fibrous carboxymethyl cellulose insoluble salt, were mixed and dispersed in water to prepare a mixed fiber raw material, and a polyamide epichlorohydrin resin (product name WS570 manufactured by PMC Japan, Inc.) was prepared. The raw material for papermaking of the surface layer was prepared by adding 8% by weight to the mixed fiber raw material to prepare a wet paper for the surface layer having a basis weight of 15 g / m ² .

The wet paper web of the liquid absorbing layer was used as an intermediate layer, and the wet paper web of the surface layer was superposed on both surfaces of the wet paper web.
After pressurizing at ² for 5 minutes, it was brought into contact with a heating mirror plate of a rotary dryer and dried to prepare a three-layer assembling type handmade paper. The obtained handmade paper was evaluated for water absorption, wet tensile strength, wet surface strength, wet sliminess, and deodorizing ability. The results are shown in Table 4.

Example 14 A polyethylene polyamine resin synthesized from tetraethylenepentamine and ethylene dichloride was used as a cationic water-soluble polymer added to the fibrous carboxymethylcellulose Na salt of the liquid-absorbing layer, and this was fibrous. Carboxymethyl cellulose Na
Using water-absorbent fibers obtained by adding 2.0% by weight to the salt and stirring, and except that the composition of the paper material for the liquid-absorbent layer and the surface layer is as shown in Table 4, Similar to Example 13,
A three-layer laminated type handmade paper was prepared.

The resulting handmade paper was evaluated for water absorption, wet tensile strength, wet surface strength, wet sliminess and deodorizing ability. The results are shown in Table 4.

(Example 15) A diamine-epichlorohydrin resin synthesized from hexamethylenediamine and epichlorohydrin was used as the cationic water-soluble polymer added to the fibrous carboxymethylcellulose Na salt of the liquid-absorbent layer, except that In the same manner as in 14, a three-layer paper making type handmade paper was produced.

The obtained handmade paper was evaluated for water absorption, wet tensile strength, surface strength in a wet state, sliminess in a wet state, and deodorizing ability. The results are shown in Table 4.

The three-layer laminated handmade papers of Examples 13 to 15 have a water absorption amount of 4 times or more of their own weight, and show the same water absorption amount as the single-layer handmade paper of the comparative example. The wet tensile strength is about twice as high as that of the comparative example. Regarding the wet surface strength, Examples 13 to 15 are torn, fluffing is extremely small, and the surface strength is higher than that of the comparative example. further,
Examples 13 to 15 have a deodorization rate of ammonia / amine malodor of 99% or more, and are clearly superior to Examples 1 to 12 in which only fibrous carboxymethyl cellulose is blended.

Examples 16 and 17 Monomethylamine, epichlorohydrin and N, N, N ', N'-tetramethyl-as cationic water-soluble polymer added to the fibrous carboxymethyl cellulose Na salt of the liquid-absorbent layer.
A primary amine / epichlorohydrin / ditertiary amine polyaddition polymer (cation equivalent 4.5 meq / g) synthesized from 1,2-diaminoethane was used. Example 1 except that the configuration shown in FIG.
In the same manner as in 3, a three-layer paper making type handmade paper was produced.

The handmade paper was size-press coated with a 3 wt% sulfuric acid band solution. The obtained handmade paper was evaluated for water absorption, wet tensile strength, wet surface strength, wet sliminess, and deodorizing ability. The results are shown in Table 4.

Since the sulfuric acid band reacts with the fibrous carboxymethylcellulose to form a fibrous carboxymethylcellulose aluminum salt, the deodorizing effect on ammonia and trimethylamine is as excellent as when the fibrous carboxymethylcellulose aluminum salt is made into paper. There is a side effect of increasing wet surface strength.

Example 18 Fibrous carboxymethylcellulose Na salt (manufactured by Nichirin Kagaku Co., Ltd., degree of etherification 0.43, degree of base saturation 82%) was dispersed in water to give 1.
A dispersion having a concentration of 5% was prepared. Polyethyleneimine resin (manufactured by Nippon Shokubai Chemical Co., Ltd., trade name Epomin SP200, number average molecular weight 20000, branched structure,
80% by weight of water-absorbent fibers obtained by adding (containing primary, secondary, and tertiary nitrogen atoms) to the above-mentioned Na salt of fibrous carboxymethylcellulose at a ratio of 2.0% by weight, and a softwood as a fiber for papermaking. 20% by weight of bleached kraft pulp was blended to prepare a raw material for paper making of the liquid absorbing layer, to prepare a wet paper B for liquid absorbing layer having a basis weight of 55 g / m ² .

Separately, 10% by weight of fibrous carboxymethyl cellulose (manufactured by Nichirin Chemical Co., Ltd., degree of etherification 0.43, base saturation 0%, free acid type), 10% by weight of softwood bleached kraft pulp, and fibrous carboxymethylcellulose. CMC-Fe (II) which is a salt (base saturation 8%) 8
A mixed fiber raw material prepared by blending 0% by weight and dispersed in water was prepared, and a polyamide epichlorohydrin resin (product name WS570 manufactured by Japan PMC Co., Ltd.) was added to the mixed fiber raw material at a ratio of 8% by weight to the surface. The raw material for paper making of layer A was prepared to prepare wet paper A for surface layer having a basis weight of 15 g / m ² .

Separately, fibrous carboxymethyl cellulose (manufactured by Nichirin Chemical Co., Ltd., degree of etherification 0.43,
Prepare a mixed fiber raw material in which 70% by weight of base saturation, 70% by weight of free acid type and 30% by weight of bleached softwood kraft pulp are mixed and dispersed in water, and a polyamide epichlorohydrin resin (trade name WS570 manufactured by PMC Japan, Inc.) is prepared. ) Was added to the mixed fiber raw material at a ratio of 8% by weight to prepare a papermaking raw material for the surface layer C to prepare a wet paper web C having a basis weight of 15 g / m ² .

With the liquid absorbent layer wet paper B as an intermediate layer, the surface layer wet paper A is placed on one surface and the surface wet paper C is placed on the other surface, and 3.5 Kg / cm ² is applied through a filter paper for water extraction. After pressurizing for 5 minutes, it was dried by bringing it into contact with a heating mirror plate of a rotary dryer to prepare a three-layer machine-made handmade paper which was machined in an ABC arrangement.

The obtained handmade paper was evaluated for water absorption, wet tensile strength, surface strength in a wet state, sliminess in a wet state, and deodorizing ability. The results are shown in Table 5.

The three-layer hand-made handmade paper of Example 18 had a water absorption of 4 times or more of its own weight and showed a water absorption similar to that of the single-layer handmade paper of the comparative example, while it was wet. The tensile strength is about twice as high as that of the comparative example. Regarding the wet surface strength, in Example 18, breakage and fluffing were extremely small, and the surface strength was higher than that in Comparative Example. Further, Example 18 has a deodorizing rate of 99% or more of the ammonia / amine type malodor, and it is clear that it has a more excellent deodorizing effect as compared with Examples 1-12.

Further, due to the water-repellent action of the CMC-Fe (II) salt, when water was dropped on the surface layer A, it was repelled as a water drop and did not penetrate into the paper for several hours. When water was dropped on the surface layer C, the water drops were immediately absorbed in the paper and no water repellency was observed. Therefore, it is clear that the three-layer laminated type handmade paper of Example 18 has a two-sided property that one side is hydrophilic and the other side is water-repellent.

[0093]

[Table 1]

[0094]

[Table 2]

[0095]

[Table 3]

[0096]

[Table 4]

[0097]

[Table 5]

[0098]

EFFECTS OF THE INVENTION The swellable laminated sheet of the present invention shows a high water absorption amount while maintaining the sheet form, and has high tensile strength and surface strength even in a wet state after absorbing a liquid. It can be used in a wide range of fields that need it. Furthermore, since it also has a deodorizing effect on malodorous substances, it can be used for various applications requiring liquid absorption and deodorization.

Claims (8)

[Claims] 1. A liquid-absorbent layer containing a water-absorbent fiber in which a polyelectrolyte complex with a cationic water-soluble polymer is formed on at least a part of a fibrous carboxymethyl cellulose water-soluble salt, and a polyfunctional on at least one surface Swellable laminated sheet, characterized in that a surface layer containing fibrous carboxymethyl cellulose cross-linked with a water-soluble resin is laminated by laminating and joining. 2. The swellable laminated sheet according to claim 1, wherein the liquid absorbing layer contains papermaking fibers. 3. The swellable laminated sheet according to claim 1, wherein the surface layer contains papermaking fibers. 4. The swellable laminated sheet according to claim 2, wherein the papermaking fiber is at least one selected from plant pulp, semi-synthetic fiber and synthetic fiber. 5. The swellable laminated sheet according to claim 1, wherein the liquid absorbing layer contains a fibrous carboxymethyl cellulose insoluble salt. 6. The swellable laminated sheet according to claim 1, wherein the surface layer contains a fibrous carboxymethyl cellulose insoluble salt. 7. The swellable laminated sheet according to claim 5, wherein the insoluble salt of fibrous carboxymethyl cellulose is an aluminum salt, iron salt or zinc salt of fibrous carboxymethyl cellulose. 8. The cationic water-soluble polymer is chitosan, a polymer having a primary, secondary, tertiary or quaternary nitrogen atom in the side chain of the polymer and a primary, secondary, or tertiary in the main chain of the polymer. The swellable laminated sheet according to any one of claims 1 to 7, which is at least one selected from polymers having a primary or quaternary nitrogen atom.