JP2020151700A - Liquid absorption body, liquid absorption device, and liquid discharge device - Google Patents

Abstract

To provide a liquid absorption body and a liquid absorption device which have good absorbency of dye ink even when an anionic water absorption resin is used, and a liquid discharge device.SOLUTION: A liquid absorption body includes a first base material containing a fiber, a second base material containing a fiber, and a plurality of small pieces including a water absorption resin carried between the first base material and the second base material, in which an ion scavenger is contained in the first base material.SELECTED DRAWING: Figure 2

Description

The present invention relates to a liquid absorber, a liquid absorber and a liquid discharge device.

In an inkjet printer, waste ink is usually generated during a head cleaning operation performed to prevent deterioration of print quality due to ink clogging and an ink filling operation after replacing an ink cartridge. In order to absorb such waste ink, a liquid absorber provided with a liquid absorber is used.

For example, Patent Document 1 discloses an absorbent composite containing an N-vinyllactam-based crosslinked polymer and a base material, in which the polymer and the base material are composited at a specific mass ratio, and the composite is an ink. There is a description that it is an ink absorbent with excellent liquid absorption capacity.

International Publication No. 2018/0087758

Patent Document 1 describes that the N-vinyllactam crosslinked polymer has a crosslinked structure, so that it absorbs water and other solvents, swells and gels. However, since such a polymer is nonionic, the absorption performance of an aqueous liquid is not necessarily high as compared with a super absorbent polymer (SAP) having an anionic group in the main chain such as polyacrylic acid.

Further, a water-absorbent resin having an anionic group such as polyacrylic acid has high absorption performance of an aqueous liquid, but if the water or aqueous solution to be absorbed contains a high concentration of ions, the absorption rate and absorption The amount decreases. Therefore, for example, when an anionic water-absorbent resin is applied to an application for absorbing a dye ink having a high electrolyte concentration, a desired absorption characteristic may not be obtained. Therefore, a liquid absorber, a liquid absorber, and a liquid ejection device having good absorbency of dye ink even when an anionic water-absorbent resin is used are provided.

One aspect of the liquid absorber according to the present invention is
The first base material containing fibers and
A second base material containing fibers and
A water-absorbent resin supported between the first base material and the second base material,
Including multiple small pieces including
The first base material contains an ion scavenger.

In the mode of the liquid absorber,
The first base material may contain the ion scavenger in an amount of 0.25 parts by mass or more and 30.0 parts by mass or less when the first base material is 100.0 parts by mass.

In any of the above liquid absorbers,
The ion trapping agents include polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polysaccharides, pectin, guar gum, amphoteric ionic polymers, ion exchange resins, modified polymers thereof, and zeolites, montmorillonites, bentonites, clays, activated carbons, and the like. Alternatively, it may be selected from a plurality of mixtures thereof.

In any of the above liquid absorbers,
The ion scavenger is polyvinylpyrrolidone and
The weight average molecular weight (Mw) of the polyvinylpyrrolidone may be 9000 or more and 2800000 or less.

In any of the above liquid absorbers,
The ion scavenger is polyvinyl alcohol,
The viscosity of the 4.0 mass% aqueous solution of polyvinyl alcohol at 20 ° C. is 4.5 mPa · s or more and 122.0 mPa · s or less, and
The degree of saponification of the polyvinyl alcohol may be 38.0% or more and 99.0% or less.

In any of the above liquid absorbers,
The ion scavenger is modified polyvinyl alcohol,
The base material containing the modified polyvinyl alcohol may contain the polymer in an amount of 0.25 parts by mass or more and 20.0 parts by mass or less when the base material is 100.0 parts by mass.

In any of the above liquid absorbers,
The fiber and the ion scavenger may be chemically bonded by a cross-linking agent.

One aspect of the liquid absorber according to the present invention is
With the liquid absorber of any of the above embodiments,
The container in which the liquid absorber is housed and
To be equipped.

One aspect of the liquid discharge device according to the present invention is
With the liquid discharge head,
The liquid absorber of the above-described embodiment that absorbs the liquid discharged from the liquid discharge head,
including.

The schematic diagram of the cross section of one small piece contained in the liquid absorber which concerns on embodiment. The perspective view which shows typically an example of the external shape of the small piece which concerns on embodiment. The figure which shows typically the liquid absorber which concerns on embodiment. The figure for demonstrating the manufacturing method of the small piece which concerns on a liquid absorber. The figure for demonstrating the manufacturing method of the small piece which concerns on a liquid absorber. The figure for demonstrating the manufacturing method of the small piece which concerns on a liquid absorber. The figure for demonstrating the manufacturing method of the small piece which concerns on a liquid absorber. The cross-sectional view which shows typically the liquid absorber which concerns on embodiment. The plan view which shows typically the liquid absorber which concerns on embodiment. The figure which shows typically the liquid discharge device which concerns on embodiment.

An embodiment of the present invention will be described below. The embodiments described below describe examples of the present invention. The present invention is not limited to the following embodiments, and includes various modifications implemented without changing the gist of the present invention. It should be noted that not all of the configurations described below are essential configurations of the present invention.

1. 1. Liquid absorber The liquid absorber 100 according to the present embodiment includes a plurality of small pieces 10.

1.1. A plurality of small pieces 10 contained in the small piece liquid absorber 100 each absorb liquid. When each of the small pieces 10 absorbs the liquid, the liquid absorber 100, which is an aggregate thereof, can absorb the liquid.

FIG. 1 is a schematic cross-sectional view of one small piece 10 included in the liquid absorber 100 of the present embodiment. The small piece 10 contains a first base material 1, a second base material 2, and a water-absorbent resin 3.

1.1.1. Base material The first base material 1 and the second base material 2 both have a sheet-like shape. The first base material and the second base material 2 contain fibers. Examples of the fibers include synthetic resin fibers such as polyester fibers and polyamide fibers, and natural resin fibers such as cellulose fibers, keratin fibers, and fibroin fibers.

The fibers contained in the first base material 1 and the second base material 2 are preferably cellulose fibers. Since the cellulose fiber is a hydrophilic material, when a liquid is applied to the small piece 10, it may be compatible with the liquid to hold the liquid or bring the liquid into contact with the water-absorbent resin 3. It's easy.

Further, since the cellulose fiber has a high affinity with the water-absorbent resin 3, it is easy to support the water-absorbent resin 3 on the surface of the fiber. Further, since cellulose fiber is a renewable natural material and is inexpensive and easily available among various fibers, it is advantageous from the viewpoints of reduction of production cost, stable production, reduction of environmental load and the like. The cellulose fiber may be a fiber containing cellulose as a compound as a main component and may contain hemicellulose or lignin in addition to cellulose.

The average length of the fibers is preferably 0.1 mm or more and 7.0 mm or less, more preferably 0.1 mm or more and 5.0 mm or less, and even more preferably 0.1 mm or more and 3.0 mm or less. The average width of the fibers is preferably 0.5 μm or more and 200.0 μm or less, and more preferably 1.0 μm or more and 100.0 μm or less. The average aspect ratio of the fibers, that is, the ratio of the average length to the average width is preferably 10 or more and 1000 or less, and more preferably 15 or more and 500 or less. Within such a range, the water-absorbent resin 3 can be supported, the liquid can be held by the fibers, and the liquid can be contacted with the water-absorbent resin 3, and the liquid absorption characteristics of the small piece 10 can be improved. ..

At least one of the first base material 1 and the second base material 2 contains an ion scavenger. Both the first base material 1 and the second base material 2 may contain an on-scavenger.

1.1.2. Ion trapping agents Examples of ion trapping agents include polymers that do not release ions when in contact with water, ion exchange resins, modified polymers thereof, and inorganic adsorptive substances such as zeolite, montmorillonite, bentonite, clay, and activated carbon. , And a plurality of mixtures thereof.

1.1.2.1. Polymers that do not release ions when they come into contact with water Polymers that do not release ions when they come into contact with water (hereinafter sometimes referred to as "nonion polymers") are hydrogen ions and metals when they come into contact with water. Do not release ions such as ions, ammonium ions, chloride ions, and hydroxide ions into water.

The nonionic polymer has water solubility (hydrophilicity). Examples of such nonionic polymers include polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), vinyl acetate and vinyl alcohol copolymers, polyethylene glycol (PEG), betaine polymers (amphoteric ionic polymers), polysaccharides ( Polysaccharides, guar gum, pectin), and polymers containing these structures in the main chain or side chains, and mixtures thereof. Further, the nonionic polymer may be a modified polymer in which, for example, silanol groups, hydroxyl groups, groups that are reactive by heat, etc. are bonded. In addition, the nonionic polymer may have a crosslinked structure.

As a specific example of nonion polymer, PVP is manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name "Pitzcol" series, PVA is manufactured by Nippon Synthetic Chemical Co., Ltd., product name "Gosenol" series, manufactured by Denka Co., Ltd. Examples include the "Denka Poval" series, manufactured by Kuraray Co., Ltd., and the product name "Kuraray Poval" series. As a specific example of the nonionic polymer, the polysaccharide is manufactured by Mitsubishi Chemical Foods Co., Ltd., trade name "Tamarind Seed Gum", and the betaine polymer is manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "RAM Resin" series ( Carboxybetaine type: (ethyl betaine methacrylate / Acrylate) polymer), and examples of the silanol-modified polyvinyl alcohol include the Kuraray Co., Ltd., trade name "Kuraray Cyranol-modified Poval" series.

The nonionic polymer preferably does not form a solution when in contact with water or an organic solvent. For example, when the molecular weight of the nonionic polymer is high, the solubility in water or an organic solvent is lowered, and when cross-linking is introduced, the solubility in water or an organic solvent is lowered. When the nonionic polymer has a high molecular weight or has crosslinks, it tends to swell or gel when it comes into contact with water or an organic solvent. As described above, the solubility of the nonionic polymer can be adjusted by the molecular weight, the degree of cross-linking and the like. If the nonionic polymer is prevented from dissolving in water or an organic solvent, even if the liquid comes into contact with the small piece 10, it tends to stay in the gap between the fibers, and it is easy to maintain the state contained in the base material.

The nonionic polymer can absorb water and an organic solvent in the liquid applied to the small piece 10. Further, when the liquid is ink or the like, the nonionic polymer can adsorb the coloring material in the ink. In particular, when the liquid is a dye ink, the dye in the ink can be adsorbed and retained (captured). In addition, the nonionic polymer is compatible with the dye, and by incorporating this into the fiber of the base material having a large surface area, the chance of contact with the dye is enhanced.

11.2.2. Ion exchange resin Examples of the ion exchange resin include a cation exchange resin that captures cations and an anion exchange resin that captures anions.

The cation exchange resin has a function of capturing cations in a liquid and releasing hydrogen ions. For example, when the cation exchange resin comes into contact with the aqueous solution, it captures the cations in the aqueous solution and releases hydrogen ions accordingly. The released hydrogen ions are neutralized by, for example, hydroxide ions in an aqueous solution to generate water.

The cation exchange resin can remove cations such as metal ions and ammonium ions. Such a cation exchange resin is sometimes called "H type".

The cation exchange resin is classified into a strongly acidic cation exchange resin and a weakly acidic cation exchange resin according to the strength of the functional group as an acid, and any of them can be used. Considering the efficiency of cation exchange, it is preferable to use a strongly acidic cation exchange resin having a stronger acid strength.

The properties of the cation exchange resin may be a porous type, or a more general-purpose and inexpensive gel type may be used. The outer shape of the cation exchange resin may be any shape such as scaly, needle-like, fibrous, and particulate, but most of them are preferably particulate. When the cation exchange resin is in the form of particles, it may be easier to support the water-absorbent resin 3 on the fibers of the first base material 1 and the second base material 2.

Further, also in the cation exchange resin, 0.15 ≦ L when the average particle size is D [μm] and the average length of the fibers of the first base material 1 and the second base material 2 is L [μm]. It is preferable to satisfy the relationship of / D ≦ 467, more preferably to satisfy the relationship of 0.25 ≦ L / D ≦ 333, and further preferably to satisfy the relationship of 2 ≦ L / D ≦ 200. The average particle size of the cation exchange resin may be adjusted by pulverization according to a conventional method, if necessary.

The content of the cation exchange resin in the small piece 10 is preferably 0.01 parts by mass or more and 100.0 parts by mass or less, more preferably 0.25 parts by mass, when the base material is 100.0 parts by mass. It is 30.0 parts by mass or less. As a result, the small piece 10 can sufficiently secure the absorption characteristics and the permeability to the dye ink.

Commercially available products of the cation exchange resin that can be used for the small piece 10 of the present embodiment include Toa Synthetic Co., Ltd., trade name "IXE-100" and its series, Organo Corporation, Amberlite series, and trade name "IR120B". , "IR124", "FPC3500", "IPC76", Amberlist series, product names "15DRY", "15JWET", "16WET", "31WET", "35WET", etc., manufactured by Mitsubishi Chemical Corporation, gel type diamond ion SK series (H type), product names "SK104", "SK1B", porous type diamond PK series (H type), product names "PK212", "PK216", "PK228", etc., Fujifilm Wako Pure Chemical Industries, Ltd. Manufacture, trade name "solid super strong acid (sulfated zirconia (SO ₄ / ZrO ₂ ))" and the like, "carbon-based solid acid catalyst" manufactured by GS Alliance Co., Ltd. and the like.

The anion exchange resin has a function of capturing anions in a liquid and releasing hydroxide ions. For example, when the anion exchange resin comes into contact with the aqueous solution, it captures the anions in the aqueous solution and releases hydroxide ions accordingly. The released hydroxide ions are, for example, neutralized by hydrogen ions in an aqueous solution to produce water.

The anion exchange resin has a relatively small molecular weight such as an anion having a relatively small molecular weight such as an anion when acetic acid, sulfuric acid, sodium chloride or the like is ionized, or an anion having a dye, a protein, a nucleic acid or the like when ionized. Large anions can be removed. Such an anion exchange resin is sometimes called "OH type".

Anion exchange resins that can be used as anion exchange resins are classified into strongly basic anion exchange resins and weakly basic anion exchange resins according to the strength of the functional group as a base, and any of them can be used. .. Further, the properties of the anion exchange resin may be a porous type, or a more general-purpose and inexpensive gel type may be used. The outer shape of the anion exchange resin may be any shape such as scaly, needle-like, fibrous, and particulate, but it is preferable that most of them are particulate. When the anion exchange resin is in the form of particles, it can be more preferably supported by the fibers.

Further, also in the anion exchange resin, 0.15 when the average particle size is D [μm] and the average length of the fibers contained in the first base material 1 and the second base material 2 is L [μm]. It is preferable to satisfy the relationship of ≦ L / D ≦ 467, more preferably to satisfy the relationship of 0.25 ≦ L / D ≦ 333, and further preferably to satisfy the relationship of 2 ≦ L / D ≦ 200. .. Further, the average particle size of the anion exchange resin may be adjusted by pulverization by a conventional method, if necessary.

Commercially available anion exchange resins include "IXE" series manufactured by Toa Synthetic Co., Ltd., product names "IXE-500", "IXE-530", "IXE-550", "IXE-700F", and "IXE-". 700D "," IXE-800 ", etc., manufactured by Organo Corporation, Amber Light series, product names" IRA400J OH "," IRA402BL OH "," IRA404J OH "," IRA900J OH "," IRA904 OH "," IRA458RF OH " , "IRA958 OH", "IRA900J OH", etc., manufactured by Mitsubishi Chemical Corporation, gel type diamond ion SA series (I type) series (OH type), trade name "SA10A" and the like.

The outer shape of the ion exchange resin may be any shape such as scale-like, needle-like, fibrous, and particle-like, but it is preferable that most of them are particle-like. When the ion exchange resin is in the form of particles, the permeability of water can be easily ensured. Further, if it is in the form of particles, it may be easier to support the ion exchange resin on the fibers of the first base material 1 and the second base material 2. The particulate state means that the aspect ratio, that is, the ratio of the maximum length to the minimum length is 0.3 or more and 1.0 or less. The average particle size of the particles is preferably 0.15 μm or more and 800.0 μm or less, more preferably 15.0 μm or more and 400.0 μm or less, and even more preferably 15.0 μm or more and 50.0 μm or less.

As the average particle size of the particles, for example, a volume average particle size MVD (Mean Volume Diameter) measured by a laser diffraction type particle size distribution measuring device can be used. A particle size distribution measuring device based on a laser diffraction / scattering method, that is, a laser diffraction type particle size distribution measuring device, can measure a particle size distribution on a volume basis.

11.2.3. Inorganic adsorptive substance The inorganic adsorptive substance is a substance having a large specific surface area such as a porous inorganic polymer and a layered compound. The inorganic adsorptive substance can function as an ion scavenger and can adsorb and capture at least one of a cation and an anion.

Specific examples of the inorganic adsorptive substance include porous aluminosilicates such as zeolite, phyrosilicates (layered clay minerals) such as montmorillonite, bentonite, smectite, and clay, and activated carbon. Among these, the inorganic adsorbent is more preferably selected from zeolite, montmorillonite, bentonite, clay and activated carbon. The outer shape of the inorganic adsorptive substance is the same as that of the ion exchange resin described above.

1.1.3. Supporting the ion scavenger The ion scavenger exemplified above is contained in at least one of the first base material 1 and the second base material 2, and the present forms in the base material include particulate, film, and. These forms can coexist. In the following description, the first base material 1 and the second base material 2 are referred to as "base materials", and the form in which the ion scavenger is contained in the base material will be described.

Although the base material contains fibers, the ion scavenger may be present in the base material in a form of adhering to the fibers or in a form of coating the fibers. Further, the functional group of the fiber and the functional group of the ion scavenger may be reacted to exist in a form in which the fiber and the ion scavenger are chemically bonded. For example, when the ion scavenger has a silanol group and the fiber is cellulose, the silanol group of the ion scavenger reacts with the hydroxyl group of the cellulose to chemically bond the fiber and the ion scavenger. The substrate can contain an ion scavenger in a bound form.

Further, even when the fiber and the ion scavenger are chemically bonded by the cross-linking agent, the ion scavenger is less likely to fall off from the fiber, which is preferable. For example, when the ion trapping agent has a hydroxyl group and the fiber is cellulose, the hydroxyl group of the ion trapping agent and the hydroxyl group of the cellulose are crosslinked with a cross-linking agent such as diisocyanate to obtain the fiber and the ion trapping agent. The base material can contain an ion trapping agent in a chemically bonded form.

When the fiber and the ion scavenger are chemically bonded by the cross-linking agent, the cross-linking agent to be used can be appropriately selected depending on the type of the functional group of the ion scavenger and the functional group of the fiber. As the cross-linking agent, for example, block polyisocyanates, diisocyanates, silane coupling agents, and the like can be preferably used.

The blocked polyisocyanate is not particularly limited as long as it contains at least two or more isocyanate groups in one molecule. Examples of the basic skeleton of the blocked polyisocyanate include aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. From the viewpoint of less yellowing, alicyclic polyisocyanates and aliphatic polyisocyanates are more preferable.

Examples of the aromatic polyisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate and its mixture (TDI), diphenylmethane-4,4'-diisocyanate (MDI), and naphthalene-1,5-diisocyanate. , 3,3-Dimethyl-4,4-biphenylenediocyanate, crude TDI, polymethylenepolyphenyldiisocyanate, crude MDI, phenylenediocyanate, xylylene diisocyanate and other aromatic diisocyanates.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, and cyclohexane diisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate and the like.

Examples of the polyisocyanate derivative that forms the basic skeleton of the blocked polyisocyanate include active hydrogen in addition to the above-mentioned polyisocyanate multimers (for example, dimer, trimer, pentamer, hepta, etc.). Examples thereof include compounds obtained by reacting one or more compounds with a compound. Such compounds include allophanate modified products (for example, allophanate modified products produced by the reaction of polyisocyanate with alcohols) and polyol modified products (for example, polyol modified products produced by the reaction of polyisocyanate with alcohols). Body (alcohol adduct), etc.), biuret modified product (for example, biuret modified product produced by reaction of polyisocyanate with water or amines, etc.), urea modified product (for example, produced by reaction of polyisocyanate with diamine) Urea modified product, etc.), oxadiazine trione modified product (for example, oxadiazine trione produced by the reaction of polyisocyanate with carbonic acid gas, etc.), carbodiimide modified product (carbodiimide modification produced by decarbonate condensation reaction of polyisocyanate) (Body, etc.), uretdione denatured product, uretonimine denatured product, etc.

Specific examples of the blocked polyisocyanate include, for example, Maycanate CX and SU-2.
68A, Meikanate TP-10 (all trade names manufactured by Meisei Chemical Works, Ltd.), Elastron BN-69, Elastron BN-77, Elastron BN-27 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Aqua BI200, Aqua BI220 (both manufactured by Baxenden), Takelac WS series (manufactured by Mitsui Chemicals, Inc.) and the like can be mentioned.

When the base material is 100.0 parts by mass, the ion trapping agent is 0.1 parts by mass or more and 30.0 parts by mass or less, preferably 0.25 parts by mass or more and 30.0 parts by mass or less. It is more preferably 0.5 parts by mass or more and 20.0 parts by mass or less, and further preferably 5.0 parts by mass or more and 15.0 parts by mass or less.

When polyvinylpyrrolidone (PVP) is selected as the ion scavenger, the weight average molecular weight (Mw) of polyvinylpyrrolidone is preferably 9000 or more and 280000 or less, and more preferably 45000 or more and 120000 or less. The weight average molecular weight can be measured according to JIS K 72752-3 "Part 3: Method near room temperature".

When polyvinyl alcohol (PVA) is selected as the ion scavenger, the viscosity of an aqueous solution of 4.0% by mass of polyvinyl alcohol at 20 ° C. is 4.5 mPa · s or more and 122.0 mPa · s or less, and polyvinyl alcohol. The degree of saponification is preferably 38.0% or more and 99.0% or less. When polyvinyl alcohol (PVA) is selected as the ion scavenger, the viscosity of an aqueous solution of 4.0% by mass of polyvinyl alcohol at 20 ° C. is 48.0 mPa · s or more and 122.0 mPa · s or less, and It is more preferable that the degree of saponification is 86.5% or more and 99.0% or less. The degree of kenification is JIS
It can be measured according to K 6726 1994 "Polyvinyl alcohol test method".

Further, when modified polyvinyl alcohol (silanol-modified polyvinyl alcohol) is selected as the ion trapping agent, the base material containing the modified polyvinyl alcohol is the modified polyvinyl alcohol when the base material is 100.0 parts by mass. Is preferably contained in an amount of 0.25 parts by mass or more and 20.0 parts by mass or less.

The ion scavenger can be applied to the substrate in the form of, for example, an aqueous solution or an aqueous dispersion. In this case, for example, an aqueous solution of an ion scavenger or an aqueous dispersion is applied to the base material by spray coating, brush coating, roller coating, an inkjet method, or the like, and dried as necessary to provide the ion scavenger to the base material. Can be contained. Further, if necessary, the cross-linking agent solution may be further applied by spray coating, brush coating, roller coating, an inkjet method, or the like. Further, a solution of the ion scavenger and the cross-linking agent may be applied to the substrate at once.

The first base material 1 and the second base material 2 may contain substances other than fibers and ion scavengers. Examples of such a substance include a binder that binds fibers together. Therefore, specific examples of the raw materials of the first base material 1 and the second base material 2 include paper containing used paper, non-woven fabric, pulp sheet and the like.

The first base material 1 and the second base material 2 may be made of different materials, including the contained ion scavenger, or may be made of the same material. However, when the first base material 1 and the second base material 2 are made of the same material, one base material can be folded to form a small piece 10 as described later, and the small pieces 10 can be easily manufactured. preferable.

1.1.4. Water-absorbent resin The water-absorbent resin 3 is arranged between the first base material 1 and the second base material 2. The water-absorbent resin 3 is the first
It is supported between the base material and the second base material 2. The water-absorbent resin 3 may be directly supported on the first base material 1 and the second base material 2 due to the adhesiveness of the surface of the water-absorbent resin 3 itself.

Since the water-absorbent resin 3 is arranged between the first base material 1 and the second base material 2, it is suppressed that the water-absorbent resin 3 falls off from the first base material 1 and the second base material 2. .. Further, as shown in FIG. 1, a part of the first base material 1 and the second base material 2 may enter from the inner surface to the inside. That is, the water-absorbent resin 3 may be partially impregnated with the first base material 1 and the second base material 2. By doing so, the supporting force of the first base material 1 and the second base material 2 on the water-absorbent resin 3 can be further increased.

The water-absorbent resin 3 is SAP (Super Absorbent Polymer) having water absorption. Water absorption refers to the function of taking in and retaining surrounding water molecules. The water-absorbent resin 3 may swell and gel by absorbing water. Specifically, the water-absorbent resin 3 absorbs water in a liquid or a liquid such as a hydrophilic organic solvent.

Examples of the water-absorbent resin 3 include carboxymethyl cellulose, polyacrylic acid, polyacrylamide, starch-acrylic acid graft copolymer, hydrolyzate of starch-acrylonitrile graft copolymer, vinyl acetate-acrylic acid ester copolymer, and the like. Examples thereof include copolymers of isobutylene and maleic acid, hydrolyzates of acrylonitrile copolymers and acrylamide copolymers, polyethylene oxides, polysulfonic acid-based compounds, polyglutamic acids, salts thereof, modified products, crosslinked products and the like. ..

As the water-absorbent resin 3, a nonionic water-absorbent resin having a small dependence on the electrolyte concentration of the liquid to be absorbed (for example, a polyvinylpyrrolidone crosslinked product manufactured by Nippon Catalyst Co., Ltd.) may be used. However, compared to a general-purpose anionic water-absorbent resin having an acid group, the absorption amount of the liquid per weight is about 1/5 to 1/20, which is inferior in the absorption amount characteristics, and the price is high. Therefore, it is preferable to use an anionic water-absorbent resin or mainly an anionic water-absorbent resin instead of using only a nonionic water-absorbent resin.

As described above, the water-absorbent resin 3 is preferably a resin having an acid group. Examples of the acid group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among these acid groups, those having a carboxyl group are more preferable because they are easily manufactured and obtained.

Examples of the resin having a carboxyl group include a polymer having a carboxyl group in the side chain, and examples of the monomer unit for obtaining such a polymer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and crotonic acid. , Fumaric acid, sorbic acid, crotonic acid and those derived from monomers such as anhydrides and salts thereof. The water-absorbent resin 3 of the present embodiment is preferably made of a polymer containing these monomer units.

When the water-absorbent resin 3 contains an acid group, the proportion of the acid group neutralized to form a salt is preferably 30.0 mol% or more and 100.0 mol% or less, and more preferably 50.0 mol%. It is 95.0 mol% or less, more preferably 60.0 mol% or more and 90.0 mol% or less, and particularly preferably 70.0 mol% or more and 80.0 mol% or less. As a result, the water-absorbent resin 3 can absorb water very well. The type of neutralizing salt in this case includes, for example, alkali metal salts such as sodium salt, potassium salt and lithium salt, and salts of nitrogen-containing basic substances such as ammonia, and among them, sodium salt is preferable.

The water-absorbent resin 3 preferably contains a poly (meth) acrylate copolymer or a poly (meth) acrylic acid polymerization crosslinked product. Poly (meth) acrylate copolymer and poly (meth)
In the acrylic acid polymerization crosslinked product, the ratio of the monomer unit having a carboxyl group to all the structural units constituting the molecular chain is preferably 50.0 mol% or more, more preferably 80.0 mol% or more, and even more. It is preferably 90.0 mol% or more.

The outer shape of the water-absorbent resin 3 may be any shape such as scale-like, needle-like, fibrous, and particle-like, but it is preferable that most of them are particle-like. When the water-absorbent resin 3 is in the form of particles, the permeability of water can be easily ensured. Further, if it is in the form of particles, it may be easier to support the water-absorbent resin 3 on the fibers of the first base material 1 and the second base material 2. The particulate state means that the aspect ratio, that is, the ratio of the maximum length to the minimum length is 0.3 or more and 1.0 or less. The average particle size of the particles is preferably 1.5 μm or more and 800.0 μm or less, more preferably 15.0 μm or more and 400.0 μm or less, and even more preferably 15.0 μm or more and 50.0 μm or less.

As the average particle size of the particles, for example, a volume average particle size MVD (Mean Volume Diameter) measured by a laser diffraction type particle size distribution measuring device can be used. A particle size distribution measuring device based on a laser diffraction / scattering method, that is, a laser diffraction type particle size distribution measuring device, can measure a particle size distribution on a volume basis.

When the average particle size of the water-absorbent resin 3 is D [μm] and the average length of the fibers of the first base material 1 and the second base material 2 is L [μm], 0.15 ≦ L / D ≦ 467 It is preferable to satisfy the relationship of .0, more preferably the relationship of 0.25 ≦ L / D ≦ 333.0, and further preferably the relationship of 2 ≦ L / D ≦ 200.0. .. The average particle size of the water-absorbent resin 3 may be adjusted by pulverization by a conventional method, if necessary.

The content of the water-absorbent resin 3 in the small piece 10 is preferably 25.0% by mass or more and 300.0% by mass or less, and more preferably 50.0% by mass or more and 150.0% by mass or less with respect to the fiber. is there. As a result, the small piece 10 can sufficiently secure the absorption property and the permeability to the liquid.

Commercially available products of the water-absorbent resin 3 suitable for the small piece 10 of the present embodiment include the trade names "Aqualic CA" and "Aqualic CS" manufactured by Nippon Shokubai Co., Ltd. and their series, and products manufactured by Sanyo Chemical Industries, Ltd. Names "Sunwet", "Sunfresh ST-500MPSA" and their series, product name "Hysorb" series manufactured by BASF Japan Co., Ltd., product name "FAVOR" series manufactured by Ebony Japan Co., Ltd., SF Co., Ltd. Examples include the "AQUASORB" series manufactured by Sanyo.

1.1.5. Shape of small piece, etc. FIG. 2 is a perspective view schematically showing an example of the outer shape of the small piece 10. The small piece 10 is a sheet in which the water-absorbent resin 3 is sandwiched and supported by the sheet-shaped first base material 1 and the second base material 2, and is finely cut into chips by a shredder or the like. Therefore, it can be said that FIG. 1 described above schematically represents a part of the small piece 10. The small piece 10 is preferably strip-shaped with flexibility. As a result, the small piece 10 is easily deformed, and it becomes easy to handle when it is stored in a container or the like.

The total length of the small piece 10, that is, the length in the long side direction is preferably 0.5 mm or more and 200.0 mm or less, more preferably 1.0 mm or more and 100.0 mm or less, and even more preferably 2.0 mm or more and 30. It is 0.0 mm or less.

The width of the small piece 10, that is, the length in the short side direction is preferably 0.1 mm or more and 100.0 mm or less, more preferably 0.3 mm or more and 50.0 mm or less, and even more preferably 1.0 mm or more and 10 It is 0.0 mm or less.

The aspect ratio of the total length and width of the small piece 10 is preferably 1 or more and 200 or less, and more preferably 1 or more and 30 or less. The thickness of the small piece 10 is preferably 0.05 m or more and 2.0 mm or less, and more preferably 0.1 mm or more and 1.0 mm or less.

Within the above range, the water-absorbent resin 3 can be supported, the liquid can be held by the fibers, and the liquid can be fed into the water-absorbent resin 3, and the liquid has excellent absorption characteristics. be able to.

1.1.6. Functions and effects of small pieces The small pieces 10 absorb liquid. As described above, the small piece 10 of the present embodiment contains the water-absorbent resin 3, and at least one of the first base material 1 and the second base material 2 contains an ion scavenger. Therefore, when the liquid comes into contact with the small piece 10, the liquid is absorbed by the first base material 1 or the second base material 2 and / or is absorbed by the water-absorbent resin 3.

When the water-absorbent resin 3 has an acid group and has good water absorption, if the concentration of ions in the liquid to be absorbed increases, the water absorption performance such as the amount of water absorption and the water absorption rate may decrease. For example, in the case of absorbing a liquid having a high electrolyte concentration such as dye ink, even if the amount of the water-absorbent resin 3 used is increased, the liquid absorption rate does not increase enough to match the increase in the amount of the water-absorbent resin 3 due to the influence of ions. ..

Here, the base material of the small piece 10 of the present embodiment contains an ion scavenger. In the small piece 10 of the present embodiment, since the ion scavenger collects the ions, the ions reach the gap between the first base material 1 and the second base material 2 in which the water-absorbent resin 3 is present from the outside. Hateful. As a result, it is possible to suppress a decrease in the water absorption performance of the water-absorbent resin 3, and it is possible to maintain good absorption of the liquid by the water-absorbent resin 3.

The liquid absorbed by the small piece 10 is not particularly limited, but is preferably an aqueous liquid. Further, since the small piece 10 of the present embodiment has the above-mentioned structure and effect, it has excellent absorption performance even for a liquid having a high electrolyte concentration. Therefore, for example, when applied to a liquid having a high ion concentration such as a dye ink, a particularly remarkable effect can be obtained.

In general, inks are roughly classified into three types: pigment inks, dye inks, and mixed inks thereof. Due to the difference in the color material of each ink, the pigment ink has a low electrolyte concentration and the absorption rate of the anionic water-absorbent resin is good, and the dye ink has a high electrolyte concentration and the absorption rate of the anionic water-absorbent resin. Is known to be relatively low.

1.2. Liquid absorber FIG. 3 is a diagram schematically showing the liquid absorber 100 of the present embodiment. As shown in FIG. 3, the liquid absorber 100 has a plurality of the above-mentioned small pieces 10. That is, the liquid absorber 100 is an aggregate of small pieces 10. The number of small pieces 10 contained in the liquid absorber 100 is not particularly limited as long as it is a plurality, but is, for example, 100 or more, preferably 200 or more, and more preferably 500 or more.

The liquid absorber 100 may include small pieces 10 having the same total length, width, aspect ratio, and thickness at least one, or may contain small pieces 10 having all different pieces.

It is preferable that the plurality of small pieces 10 constituting the liquid absorber 100 have a regular shape. As a result, the bulk density of the liquid absorber 100 is less likely to be uneven, and the unevenness of the liquid absorption characteristics can be suppressed. In the liquid absorber 100, the content of the regularly formed small pieces 10 is 30.0% by mass or more, preferably 50.0% by mass or more, more preferably 50.0% by mass or more of the entire liquid absorber 100. It is 70.0% by mass or more.

It is preferable that the plurality of small pieces 10 constituting the liquid absorber 100 are spatially randomly arranged without regularity so that the longitudinal directions intersect with each other without being aligned with each other, for example. In this way, a gap is likely to be formed between the small pieces 10. As a result, the liquid can pass through the gap between the small pieces 10, and when the gap is minute, it can be wetted and spread by the capillary phenomenon, and the liquid permeability of the liquid can be ensured. For example, when the liquid absorber 100 is housed in a container, it is possible to prevent the liquid flowing downward in the container from being blocked in the middle, and the liquid permeates smoothly toward the bottom of the container. can do.

Further, since a plurality of small pieces 10 are spatially and randomly accommodated in the container, the chance of contact with the liquid increases as the entire liquid absorber 100, so that the liquid absorber 100 has excellent absorption characteristics for the liquid. Can have. Further, when the liquid absorber 100 is housed in the container, the small pieces 10 can be randomly put into the container, so that the work can be performed easily and quickly. Further, since the small piece 10 is easily deformed, when the liquid absorber 100 composed of a plurality of small pieces 10 is housed in the container, the liquid absorber 100 is deformed and comfortably stored in the container regardless of the shape of the container. The shape followability of is good.

The bulk density of the liquid absorber 100 is preferably 0.01 g / cm ³ or more and 0.5 g / cm ³ or less, more preferably 0.03 g / cm ³ or more and 0.3 g / cm ³ or less, and even more. preferably is 0.05 g / cm ³ or more 0.2 g / cm ³ or less. This makes it possible to achieve both liquid retention and permeability.

The liquid absorber 100 may contain a material other than the above. Examples of such materials include surfactants, lubricants, defoamers, fillers, blocking inhibitors, ultraviolet absorbers, pigments, colorants such as dyes, flame retardants, and fluidity improvers.

In the liquid absorber 100 of the present embodiment, since the small piece 10 has the above-mentioned structure and effect, it has excellent absorption performance even for a liquid having a high ion concentration. Therefore, for example, when applied to a liquid having a high ion concentration such as a dye ink, a particularly remarkable effect can be obtained.

1.3. Method for Producing Liquid Absorber The method for producing the liquid absorber 100 according to the present embodiment will be described with reference to the drawings. 4 to 7 are views for explaining a method of manufacturing the small piece 10 of the liquid absorber 100. The small piece 10 of the liquid absorber 100 is manufactured, for example, as follows.

As shown in FIG. 4, a sheet-shaped sheet member 5 (for example, used paper) to be the first base material 1 and the second base material 2 is placed on the mounting table 101. Then, a liquid containing water, for example, pure water is applied to the sheet member from one surface side. Examples of this application method include application by spraying, a method in which a sponge roller is impregnated with a liquid containing water, and the sponge roller is rolled on one surface of a sheet-shaped sheet member.

As shown in FIG. 5, the water-absorbent resin 3 is applied onto the surface 5a of the sheet member 5. At this time, the water-absorbent resin 3 may be applied by spraying, but may be sprayed via a mesh or the like if necessary.

As shown in FIG. 6, after the water-absorbent resin 3 is sprayed on the sheet member 5 mounted on the mounting table 101, the sheet member 5 is placed so that the surface 5a to which the water-absorbent resin 3 is applied is on the inside. Fold.

As shown in FIG. 7, the bent sheet member 5 is arranged between the pair of heating blocks 103. Then, the pair of heating blocks 103 are heated and the pair of heating blocks 103 are pressed in the approaching direction to press the sheet member 5 in the thickness direction. As a result, the water-absorbent resin 3 softens by heating or enters the inside of the sheet member 5 by pressurization. Further, the water-absorbent resins 3 that are bent and overlapped may also be softened and joined.

Pressure in this step is preferably at 0.1 kg / cm ² or more 1.0 kg / cm ² or less, more preferably 0.2 kg / cm ² or more 0.8 kg / cm ² or less. The heating temperature in this step is preferably 80.0 ° C. or higher and 160.0 ° C. or lower, and more preferably 100.0 ° C. or higher and 120.0 ° C. or lower.

Then, by releasing the heating and pressurization, the temperature is lowered, the water-absorbent resin 3 is adhered in a state of being inside the sheet member 5, and the sheet members 5 that are bent and overlapped are further formed by the water-absorbent resin 3. Be joined. Further, when an adhesive is used, the overlapping sheet members 5 are joined with higher adhesive strength.

Next, the sheet member 5 is finely cut, coarsely crushed, and crushed with scissors, a cutter, a mill, a shredder, or the like, or finely chopped by hand to form a plurality of small pieces 10. The folded and overlapped sheet members 5 constitute the first base material 1 and the second base material 2 in the small piece 10. The aggregate of the obtained small pieces 10 is a liquid absorber 100, and after measuring a desired amount, it may be loosened by hand to adjust the bulk density and shape.

The ion scavenger is contained by adding an aqueous solution and / or an aqueous dispersion to the sheet member 5. As a method of applying, it can be applied by spray coating, brush coating, roller coating, coating by an inkjet method or the like. Such coating may be performed before the water-absorbent resin 3 is applied to the base, or may be performed after the water-absorbent resin 3 is applied to the base. That is, the ion scavenger may be finally contained in the base material when the liquid absorber 100 is manufactured.

When spray coating is performed, the sheet member 5 may be sprayed in advance, may be sprayed after heating and pressurizing, or may be sprayed after the small pieces 10 are formed. Further, when the coating is applied by a brush, a roller, an inkjet method, or the like, the sheet member 5 may be coated in advance or after heating and pressurizing. When coating with a brush, roller coating, an inkjet method, or the like, it is efficient to apply before forming the small piece 10.

When a solution of an ion scavenger or the like is applied to and sprayed on the sheet member 5, it may be applied or sprayed on one side of the sheet member 5 or on both sides.

2. 2. Liquid Absorber The liquid absorber according to the embodiment will be described with reference to the drawings. FIG. 8 is a cross-sectional view schematically showing the liquid absorber 300 according to the present embodiment. FIG. 9 is a plan view schematically showing the liquid absorber 300 according to the embodiment. Note that FIG. 8 is a cross-sectional view taken along the line II of FIG.

As shown in FIGS. 8 and 9, the liquid absorber 300 includes a liquid absorber 100, a case 20 as a container, and a lid 30. For convenience, in FIGS. 8 and 9, the liquid absorber 1 is shown.
00 is simplified and shown. Further, in FIG. 9, the tube 506 is not shown. Each configuration will be described below.

2.1. Case The case 20 is a container that houses the above-mentioned liquid absorber 100. As shown in FIG. 8, the case 20 contains the liquid absorber 100. The case 20 has, for example, a bottom portion 22 having a quadrangular planar shape, and four side wall portions 24 provided along each side of the bottom portion 22. The case 20 has a shape with an open upper portion. The planar shape of the bottom portion 22 is not limited to a quadrangle, and may be, for example, a circle.

When the volume of the case 20 is V1 and the total volume of the liquid absorber 100 before absorbing the ink is V2, the ratio V2 / V1 of V1 and V2 is, for example, 0.1 or more and 0.7 or less. , Preferably 0.2 or more and 0.7 or less.

The case 20 preferably has a shape retention property such that the volume V1 does not change by 10% or more when an internal pressure or an external force acts on the case 20. As a result, the case 20 can maintain the shape of the case 20 even if the liquid absorber 100 absorbs a liquid such as ink and expands to receive a force from the liquid absorber 100. Therefore, the installation state of the case 20 is stable, and the liquid absorber 100 can stably absorb a liquid such as ink.

The material of the case 20 is, for example, a resin material such as cyclic polyolefin or polycarbonate, or a metal material such as aluminum or stainless steel.

2.2. Lid The lid 30 closes the opening 26 of the case 20. The lid 30 covers the liquid absorber 100. The liquid absorber 100 is sandwiched between the lid 30 and the bottom 22 of the case 20. The thickness of the lid 30 is preferably 50 μm or more and 5 mm or less, and more preferably 100 μm or more and 3 mm or less. In the example shown in FIG. 9, the planar shape of the lid 30 is rectangular, but is not particularly limited.

The lid 30 has a recess 32 recessed on the liquid absorber 100 side and a peripheral portion 34 provided around the recess 32 in a plan view. The recess 32 is provided at a position where ink is discharged. The recess 32 is provided at a position including, for example, the center of the lid 30 in a plan view.

The recess 32 has a bottom portion 32a and a side wall portion 32b. In the illustrated example, the bottom portion 32a has a quadrangular planar shape. The side wall portion 32b is provided along each side of the bottom portion 32a. A side wall portion 32b is provided at a position where the ink of the lid 30 is discharged so as to surround at least a part of the position. The side wall portion 32b is connected to the bottom portion 32a. When discharging a liquid such as ink from the tube 506, as shown in FIG. 8, the tube 506 is inserted into the space defined by the recess 32 and discharged. The recess 32 can prevent bubbles from being generated and spilling out when the liquid is discharged. The recess 32 has a shape that is particularly effective for a liquid in which a large amount of surfactant is generated and bubbles are likely to be generated.

The peripheral portion 34 is a portion of the lid 30 excluding the recess 32. In the example shown in FIG. 9, the peripheral portion 34 is provided so as to surround the recess 32 in a plan view. The thickness of the liquid absorber 100 located between the peripheral portion 34 and the bottom portion 22 is larger than the thickness of the liquid absorber 100 located between the recess 32 and the bottom portion 22.

The lid 30 is provided with a through hole 36 through which a liquid passes. The through hole 36 penetrates the lid 30 in the thickness direction. The lid 30 has a surface 30a in contact with the liquid absorber 100 and a surface 30b opposite to the surface 30a. The through hole 36 penetrates from the opening 36a provided on the surface 30a to the opening 36b provided on the surface 30b. In the example shown in FIG. 9, the openings 36a and 36b have the same shape and size. The through hole 36 is provided at a position where the liquid of the lid 30 is discharged.

The through hole 36 is provided in the recess 32. In the illustrated example, the through holes 36 are provided in the bottom portion 32a, the side wall portion 32b, and the peripheral portion 34. The shape of the through hole 36 is, for example, a quadrangle, and in the illustrated example, it is a square. The through hole 36 is not limited to a square, and may be a polygon such as a rectangle, a triangle, a pentagon, or a hexagon, or a star shape such as a circle, an ellipse, or a hexagram.

A plurality of through holes 36 are provided. The number of through holes 36 is not particularly limited. In the example shown in FIG. 9, the through holes 36 are arranged in a matrix in a first direction and a second direction orthogonal to the first direction.

The material of the lid 30 is, for example, polypropylene (PP), polystyrene (PS), polyethylene (PE), polyurethane (PU), polyvinyl chloride (PVC), acrylonitril butadiene styrene (ABS), polymethylmethacrylate. (PMMA), acrylonitril styrene (AS), modified polyphenylene ether (PPE), polycarbonate (PC), polyamide (PA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylensulfide (PPS), Polysulfone (PSU), polyacetal (POM), nylon, polyether ether ketone (PEEK), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / ethylene copolymer (ETFE), polytetrafluoro It is a resin material such as ethylene (PTFE).

The lid 30 may be a mesh member or a punching member made of metal made of stainless steel wire, iron wire, copper wire or the like. Further, the surfaces 30a and 30b of the lid 30 and the inner surfaces of the through holes 36 may be treated with hydrophobicity. This makes it possible to prevent ink from accumulating on the lid 30.

Since the liquid absorber 100 described above is housed in the case 20 (container), the liquid absorber 300 described above has excellent absorption performance even for a liquid having a high concentration of ions. Therefore, for example, when applied to a liquid having a high ion concentration such as a dye ink, a particularly remarkable effect can be obtained.

3. 3. Liquid Discharge Device Next, the liquid discharge device according to this embodiment will be described with reference to the drawings. FIG. 10 is a diagram schematically showing the liquid discharge device 500 according to the present embodiment.

As shown in FIG. 10, the liquid discharge device 500 includes, for example, a liquid discharge head 502 that discharges ink Q as a liquid, a capping unit 504 that prevents clogging of the nozzle 502a of the liquid discharge head 502, and a capping unit 504. A tube 506 for connecting the ink Q and the liquid absorber 300, a roller pump 508 for sending the ink Q from the capping unit 504, and a liquid absorber 300 for collecting the waste liquid of the ink Q are included.

The liquid discharge head 502 has a plurality of nozzles 502a that discharge ink Q downward. The liquid ejection head 502 can eject ink Q and perform printing while moving to a recording medium (not shown) such as a PPC (Plain Paper Copier) sheet.

When the liquid discharge head 502 is in the standby position, the capping unit 504 sucks a plurality of nozzles 502a at once by operating the roller pump 508 to prevent clogging of the nozzles 502a.

The tube 506 is for passing the ink Q sucked through the capping unit 504 toward the liquid absorber 300. The tube 506 has, for example, flexibility.

The roller pump 508 is arranged in the middle of the tube 506. The roller pump 508 has a holding portion 508b that sandwiches the middle of the tube 506 between the roller portion 508a and the roller portion 508a. As the roller portion 508a rotates, a suction force is generated in the capping unit 504 via the tube 506. Then, as the roller portion 508a continues to rotate, the ink Q adhering to the nozzle 502a can be sent to the liquid absorber 300. The ink Q is sent to the liquid absorber 300 and absorbed as a waste liquid.

The liquid absorber 300 is detachably attached to the liquid discharge device 500. The liquid absorber 300 absorbs the ink Q discharged from the liquid discharge head 502 while being mounted on the liquid discharge device 500. The liquid absorber 300 is a so-called waste liquid tank. When the amount of ink Q absorbed by the liquid absorber 300 reaches the limit, the liquid absorber 300 can be replaced with a new unused liquid absorber 300.

Whether or not the amount of ink Q absorbed by the liquid absorber 300 has reached the limit may be detected by a detection unit (not shown) of the liquid discharge device 500. When the amount of ink Q absorbed by the liquid absorber 300 reaches the limit, a notification unit such as a monitor built in the liquid discharge device 500 may notify the fact.

Since the liquid discharge device 500 described above includes the liquid absorber 300, it has high liquid absorption performance and excellent absorption performance even for a liquid having a high ion concentration. Therefore, for example, it can exert a particularly remarkable effect on a liquid having a high ion concentration such as a dye ink.

4. Examples and Comparative Examples Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Hereinafter, "part" and "%" are based on mass unless otherwise specified.

4.1. Material of liquid absorber The materials used in Examples and Comparative Examples are as follows.
-As the base material, "PPC G80" (basis weight = about 4.0 g / sheet) manufactured by Toppan Forms Co., Ltd. was used.
-As the water-absorbent resin, Sanyo Chemical Industries, Ltd., trade name "Sunfresh ST-500MPSA" (ion dissociation type water-absorbent resin having a carboxyl group in the side chain) was used.
・ Ion scavenger ・ ・ Nonion polymer (indicated as “polymer” in the table)
・ ・ ・ Pittscall: Product name, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (model numbers are listed in the table)
・ ・ ・ RAM resin: Product name, manufactured by Osaka Organic Chemical Industry Co., Ltd. (Model numbers are listed in the table)
・ ・ ・ Kuraray Poval: Product name, manufactured by Kuraray Co., Ltd. (model numbers are listed in the table)
・ ・ ・ Denka Poval: Product name, manufactured by Denka Co., Ltd. (model numbers are listed in the table)
・ ・ ・ Gosenol: Product name, manufactured by Co., Ltd. (model numbers are listed in the table)
・ ・ ・ Kuraray silanol-modified Poval: Product name, manufactured by Kuraray Co., Ltd. (model numbers are listed in the table)
・ ・ Cation exchange resin ・ ・ ・ IXE-100: Product name, manufactured by Toa Synthetic Co., Ltd. ・ ・ ・ IXE-500: Product name, manufactured by Toa Synthetic Co., Ltd. ・ ・ Anion exchange resin ・ ・ ・ Amberlite IRA 400J: Product name, manufactured by Organo Corporation ... Diaion SA 10A: Product name, manufactured by Mitsubishi Chemical Corporation ・ Additives: "Meikanate CX" (blocked isocyanate) manufactured by Meisei Chemical Works, Ltd.
-FLOPAM EM140CT: Product name, manufactured by SNF Co., Ltd. (cationic polymer)

Tables 1 to 3 show the components and evaluation results of the liquid absorbers of Examples and Comparative Examples. Table 1 shows a series of polyvinylpyrrolidone (Examples) and betaine polymers (Examples) as nonionic polymers, and cationic polymers (Comparative Examples). Table 1 shows the weight average molecular weight of each polymer. In addition, Table 2 shows the series of polyvinyl alcohol (Example) as a nonionic polymer, and shows the viscosity (viscosity of a 4.0% by mass aqueous solution at 20 ° C.) and the saponification rate. Furthermore, Table 3 shows a series of silanol-modified polyvinyl alcohols (Examples) as nonionic polymers and combinations of polyvinyl alcohols and additives (blocked isocyanates), the viscosity and saponification rate before cross-linking, and the additives. The coating amount is described. Further, Table 4 shows the types of ion exchange resins. In each table, the amount of water-absorbent resin, the name of the ion scavenger, and the coating amount are described.

4.2. Preparation of Liquid Absorber In each Example and each Comparative Example, powders of each water-absorbent resin were prepared so as to have the amount (g) of the water-soluble resin shown in Tables 1 to 4. In the table, the case where the amount of the water-absorbent resin is 4.00 g corresponds to the amount of the water-absorbent resin supported by 4.00 g per base material (PPC paper) in the produced small pieces. To do.

The amounts (PPC) shown in Tables 1 to 4 when the ion scavenger of each example shown in Tables 1 to 4 and the additive (Meicanate CX) in Examples 47 to 67 are applied. An aqueous solution or a dispersion liquid was prepared so as to be a mass part) when the mass of the paper was 100). An aqueous solution of a cationic polymer (FLOPAM EM140CT) having the amount shown in Table 1 (the mass part when the mass of the PPC paper is 100) was prepared for use in Comparative Examples 2 to 4.

In each example, the above aqueous solution was applied to one side of the base material (A4 size) so that the amount (part) of the polymer was shown in Tables 1 to 4. Then, in each example, the water-absorbent resin was uniformly sprayed on the surface coated with the aqueous solution of the base material so as to have the masses shown in Tables 1 to 4. Then, the base material was folded in two with the side on which the water-absorbent resin was sprayed inside. It was visually confirmed that the sprayed water-absorbent resin did not fall off from the base material when the base material was bent. In Comparative Example 1, water was applied to the base material without applying an aqueous solution of the ion scavenger, and the same procedure was applied.

The bent base material of each example is sandwiched between heating blocks of a press machine (manufactured by AS ONE Corporation) having a pair of heating blocks, and a pressing force of 0.3 kg / cm ² and a heating temperature of 100 ° C. are used for 2 minutes. Pressurized and heated. The heating and pressurization were released, and the mixture was left at room temperature for 12 hours, and the sheet-shaped fiber base material was shredded into strips of 2 mm × 15 mm by a shredder (Securet series “F3143SP” manufactured by Ishizawa Seisakusho Co., Ltd.). In this way, the liquid absorber of each example was prepared.

4.3. Evaluation of Liquid Absorber A sheet of aggregate (liquid absorber) of small pieces prepared in each example was put into 200 mL of New Disposable Cup manufactured by AS ONE Corporation to prepare a liquid absorber for each example.

4.3.1. Supportability of water-absorbent resin By visually observing the amount of water-absorbent resin powder that fell on the bottom of the liquid absorber in each example, the degree of water-absorbent resin shedding was evaluated according to the following criteria, and the results were evaluated. Listed in the table.
1: No unsupported water-absorbent resin 2: Approximately a small amount of unsupported water-absorbent resin 3: Approximately 25% of unsupported water-absorbent resin
4: Approximately 50% of unsupported water-absorbent resin

4.3.3. Absorption characteristics of dye ink For the liquid absorber of each example, the absorption characteristics of the dye ink were evaluated by an inversion test as follows. As the dye ink, black (HSM-BK), cyan (HSM-C), magenta (HSM-M), and yellow (HSM-Y) inks of the HSM dye ink set manufactured by Seiko Epson are used in terms of volume ratio and Bk. Inks mixed at: C: M: Y = 3: 1: 1: 1 were used.

A sheet of aggregate (liquid absorber) of small pieces prepared in each example was put into 200 mL of a New Disposable Cup manufactured by AS ONE Corporation to prepare a liquid absorber for each example.

25 mL of dye ink was put into the liquid absorber of each example and left at 26 ° C. ± 1 ° C. for 30 minutes or 24 hours, respectively. Immediately after leaving the container, invert the container 90 ° to check the outflow of dye ink, evaluate the remaining amount of ink in the container after inversion according to the following five evaluation criteria, and list the results in the table. did.
1: No unabsorbed dye ink is found even after inversion 2: A small amount of unabsorbed dye ink is found after inversion 3: About 25% of the added dye ink is found to be unabsorbed after inversion 4: After inversion, about 50% of the added dye ink was found to be unabsorbed. 5: After inversion, more than 50% of the added dye ink was found to be unabsorbed.

4.4. Evaluation Results Tables 1 to 4 show that the first base material containing fibers, the second base material containing fibers, and the water-absorbent resin supported between the first base material and the second base material were found. The liquid absorber of each example, which contained a plurality of small pieces containing and contained an ion scavenger in the first base material, absorbed the dye ink well. On the other hand, in Comparative Example 1 to which the ion scavenger was not applied and Comparative Examples 2 to 4 in which the cationic polymer (not the ion scavenger) was used, the absorption of the dye ink was insufficient.

Looking at each example, in the case of the polyvinylpyrrolidone system (Table 1), the higher the molecular weight, the better the absorbability. In the case of the polyvinyl alcohol type (Table 2), the viscosity of the 4.0 mass% aqueous solution at 20 ° C. is 48.0 mPa · s or more and 122.0 mPa · s or less, and the degree of saponification is 86. When it was 5.5% or more and 99.0% or less, a tendency of good absorbency was observed.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration substantially the same as the configuration described in the embodiment, for example, a configuration having the same function, method and result, or a configuration having the same purpose and effect. The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. The present invention also includes a configuration that exhibits the same action and effect as the configuration described in the embodiment or a configuration that can achieve the same object. The present invention also includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 ... 1st base material, 2 ... 2nd base material, 3 ... water-absorbent resin, 5 ... sheet member, 5a ... surface, 10 ... small piece, 20 ... case, 22 ... bottom, 24 ... side wall, 26 ... opening, 30 ... lid, 30a, 30b ... surface, 32 ... concave, 32a ... bottom, 32b ... side wall, 34 ... peripheral, 36 ... through hole, 36a, 36b ... opening, 100 ... liquid absorber, 300 ... liquid absorption Vessel, 101 ... mounting table, 103 ... heating block, 500 ... liquid discharge device, 502 ... liquid discharge head, 502a ... nozzle, 504 ... capping unit, 506 ... tube, 508 ... roller pump, 508a ... roller part, 508b ... sandwiching Department

Claims (9)

The first base material containing fibers and
A second base material containing fibers and
A water-absorbent resin supported between the first base material and the second base material,
Including multiple small pieces including
A liquid absorber containing an ion scavenger in the first base material. In claim 1,
The first base material is a liquid absorber containing 0.25 parts by mass or more and 30.0 parts by mass or less of the ion scavenger when the first base material is 100.0 parts by mass. In claim 1 or 2,
The ion trapping agents include polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polysaccharides, pectin, guar gum, amphoteric ionic polymers, ion exchange resins, modified polymers thereof, and zeolites, montmorillonites, bentonites, clays, activated carbons, and the like. Also, a liquid absorber selected from a mixture thereof. In any one of claims 1 to 3,
The ion scavenger is polyvinylpyrrolidone and
A liquid absorber having a weight average molecular weight (Mw) of polyvinylpyrrolidone of 9000 or more and 2800000 or less. In any one of claims 1 to 3,
The ion scavenger is polyvinyl alcohol,
The viscosity of the 4.0 mass% aqueous solution of polyvinyl alcohol at 20 ° C. is 4.5 mPa · s or more and 122.0 mPa · s or less, and
A liquid absorber having a saponification degree of polyvinyl alcohol of 38.0% or more and 99.0% or less. In any one of claims 1 to 3,
The ion scavenger is modified polyvinyl alcohol,
The base material containing the modified polyvinyl alcohol is a liquid absorber containing 0.25 parts by mass or more and 20.0 parts by mass or less of the polymer when the base material is 100.0 parts by mass. In any one of claims 1 to 6,
A liquid absorber in which the fiber and the ion scavenger are chemically bonded by a cross-linking agent. The liquid absorber according to any one of claims 1 to 7.
The container in which the liquid absorber is housed and
With a liquid absorber. With the liquid discharge head,
The liquid absorber according to claim 8, which absorbs the liquid discharged from the liquid discharge head.
Liquid discharge device, including.

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