Liquid absorbent and printing apparatus

Abstract

To provide a liquid absorber which is superior in flame retardancy, and capable of making its liquid absorption performance superior over a long period in a stable manner, and to provide a printer comprising the liquid absorber.SOLUTION: A liquid absorber comprises a first substrate, a second substrate, and an absorption layer interposed between the first substrate and the second substrate. The first substrate and the second substrate both contains a flame retardant filament nonwoven fabric, and the content of a flame retardant additive in the absorption layer is less than 10 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a liquid absorbent and a printing apparatus. [Background technology]

[0002] In inkjet printers typically generate waste ink during head cleaning, which is performed to prevent a decrease in print quality due to ink clogging, and during ink refilling after replacing ink cartridges. Therefore, to prevent this waste ink from unintentionally adhering to the internal mechanisms of the printer, a liquid absorbent is provided to absorb the waste ink.

[0003] The liquid absorbent used to collect waste ink must be flame-retardant for printer safety. Therefore, flame retardants are added to the liquid absorbent.

[0004] Conventionally, liquid absorbents have been used that, for example, are made by mixing and unweaving natural cellulose fibers and / or synthetic fibers, a heat-fusible material, and a flame-retardant material in air to form a mat, and then heating the mat above the melting point of the heat-fusible material and compressing it with a press roll to fix the flame-retardant material into the web (see, for example, Patent Document 1).

[0005] The flame retardants added to liquid absorbents are typically composed of components that do not react easily with the ink (the liquid to be absorbed) and are less likely to form aggregates. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-311755 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, ink that remains in the ink tank for a long period of time deteriorates due to oxidation in the air, etc., and the flame retardant may react with the deteriorated ink, causing aggregation. This presented a challenge in maintaining the ink's absorption performance over the long term. [Means for solving the problem]

[0008] This invention was made to solve the above-mentioned problems and can be realized in the following application examples.

[0009] A liquid absorbent according to an application example of the present invention comprises a first substrate and The second substrate and The system comprises an absorbent layer provided between the first substrate and the second substrate, Both the first and second substrates include a flame-retardant long-fiber nonwoven fabric. The flame retardant content in the absorbent layer is less than 10% by mass.

[0010] Furthermore, the printing apparatus according to the application example of the present invention is equipped with a liquid absorbent according to the application example of the present invention. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic longitudinal cross-sectional view showing a preferred embodiment of the liquid absorbent of the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating a preferred embodiment of the apparatus used for manufacturing the liquid absorbent of the present invention. [Figure 3] Figure 3 is an external perspective view showing the overall configuration of an example of an inkjet printer, which is a printing device. [Figure 4] Figure 4 is an overall perspective view of the ink cartridges in the inkjet printer shown in Figure 3. [Figure 5] Figure 5 is an exploded perspective view of the ink cartridge shown in Figure 4. [Figure 6] Figure 6 is a longitudinal cross-sectional view of the ink cartridge shown in Figure 4. [Figure 7]FIG. 7 is an enlarged cross-sectional view of the main part of the ink cartridge shown in FIG. 4. [Figure 8] FIG. 8 is a cross-sectional view for explaining the opening / closing operation of the opening / closing valve shown in FIG. 6. (a) is a cross-sectional view showing the state where the opening / closing valve is closed, (b) is a cross-sectional view showing the state where the opening / closing valve is opened due to the pressure increase in the storage space by the introduction of waste ink, and (c) is a cross-sectional view showing the state where the opening / closing valve is closed again after the introduction of waste ink is completed. [Figure 9] FIG. 9 is a schematic exploded perspective view showing the overall configuration of an inkjet printer which is a printing apparatus. [Figure 10] FIG. 10 is an exploded perspective view of the waste ink tank provided in the inkjet printer shown in FIG. 9. [Figure 11] FIG. 11 is an enlarged cross-sectional view of the opening / closing valve provided in the waste ink tank shown in FIG. 10. [Figure 12] FIG. 12 is a longitudinal cross-sectional view showing another configuration example of the opening / closing valve. [Embodiments for Carrying Out the Invention]

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail. [1] Liquid Absorbent First, the liquid absorbent of the present invention will be described.

[0013] FIG. 1 is a longitudinal cross-sectional view schematically showing a preferred embodiment of the liquid absorbent of the present invention. Note that the drawings referred to in this specification show a part of the configuration exaggeratedly and do not accurately reflect the actual dimensions and the like.

[0014] The liquid absorbent A100 includes a first base material A1, a second base material A2, and an absorption layer A3 provided between the first base material A1 and the second base material A2. In other words, the liquid absorbent A100 has a structure in which the first base material A1, the absorption layer A3, and the second base material A2 are laminated in this order.

[0015] Furthermore, both the first base material A1 and the second base material A2 contain a flame-retardant long-fiber nonwoven fabric, and the flame retardant content in the absorbent layer A3 is less than 10% by mass.

[0016] This configuration provides excellent flame retardancy, and even when the liquid absorbent A100 comes into contact with an acidic liquid, more specifically, when the liquid in contact with the liquid absorbent A100 becomes acidic due to air oxidation, etc., it is possible to effectively prevent the formation of aggregates and provide a liquid absorbent A100 that maintains excellent liquid absorption performance stably over a long period of time. Furthermore, even when the overall liquid absorption amount is small when the usage frequency is low, it is possible to effectively prevent problems such as a significant decrease in liquid absorption performance after a predetermined period has elapsed since the start of liquid absorption.

[0017] The excellent effects obtained are thought to be due to the following reasons. In other words, in conventional liquid absorbents, the flame retardant is contained in the part of the liquid absorbent that mainly absorbs and retains the liquid. Although conventionally used flame retardants are generally poorly soluble, they are slightly soluble in liquids such as water. In such conventional liquid absorbents, if ink is left to stand for a long period of time, for example, the dissolved flame retardant reacts with the ink, forming aggregates and impairing the absorption performance of the liquid absorbent. In addition, ink that remains in a waste liquid tank for a long period of time is modified by air oxidation and temperature, etc., and the pH and functional materials contained in the ink change, beginning to exhibit chemical properties different from the original ink. This makes the reaction with the flame retardant proceed more easily, and the above problems occur more significantly. In contrast, in the liquid absorbent A100 according to the present invention, both the first base material A1 and the second base material A2 contain a flame-retardant long-fiber nonwoven fabric, and the flame retardant content in the absorbent layer A3 is less than 10% by mass. In other words, in the liquid absorbent A100 according to the present invention, the parts that mainly exhibit flame retardancy, namely the first base material A1 and the second base material A2, and the parts that mainly absorb and retain liquid, namely the absorption layer A3, are separated. Because the parts that mainly exhibit flame retardancy and the parts that mainly absorb and retain liquid are separated in this way, it is possible to effectively prevent the first base material A1 and the second base material A2, which are the parts that mainly exhibit flame retardancy, from coming into contact with the liquid and the flame retardant for a long period of time. This effectively prevents the formation of aggregates near the surface of the liquid absorbent A100, and thus allows the liquid to be suitably supplied and retained near the center of the liquid absorbent A100. Furthermore, since the first base material A1 and the second base material A2 contain long-fiber nonwoven fabric, even when the basis weight is reduced compared to those composed of short fibers, it is possible to effectively prevent unintended shedding of fibers. Therefore, the liquid permeability of the first substrate A1 and the second substrate A2 can be made particularly excellent, the liquid can be effectively supplied by the absorbent layer A3, and prolonged contact between the first substrate A1 and the second substrate A2 and the liquid and flame retardant can be more effectively prevented. For these reasons, the liquid absorber A100 according to the present invention can effectively prevent the formation of aggregates caused by liquids such as ink over a long period of time.

[0018] [1-1]First base material The first substrate A1, together with the second substrate A2, sandwiches the absorbent layer A3.

[0019] The first base material A1 contains a flame-retardant long-fiber nonwoven fabric. The first substrate A1 is usually in the form of a sheet.

[0020] Examples of long-fiber nonwoven fabrics include spunbond nonwoven fabrics, meltblown nonwoven fabrics, and spunlace nonwoven fabrics, but spunbond nonwoven fabrics are preferred.

[0021] This allows for the production of a long-fiber nonwoven fabric with uniform fiber thickness and basis weight, thereby reducing inconsistencies in absorption rate from the first substrate A1 and flame retardancy.

[0022] The flame-retardant long-fiber nonwoven fabric constituting the first base material A1 may include fibers composed of a polymer containing flame-retardant monomer components.

[0023] This makes it possible to improve the flame retardancy of the fibers themselves contained in the first base material A1, and to more effectively prevent unintentional shedding of flame-retardant components from the fibers.

[0024] When the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 contains fibers composed of a polymer containing a flame-retardant monomer component, examples of the flame-retardant monomer component include phosphorus-containing compounds, halogen-containing compounds, nitrogen-containing compounds, etc., but phosphorus-containing compounds are preferred due to the ease of controlling the polymerization reaction. This makes it possible to improve the flame retardancy of the liquid absorbent A100.

[0025] Examples of phosphorus-containing compounds as flame-retardant monomer components include compounds having a phosphaphenanthrene ring, more specifically, [(6-oxo-6H-dibenzo[c,e][1,2]oxoxan-6-yl)methyl]butanoate bis(2-hydroxyethyl) ester, phosphaphenanthrene-modified benzyl alcohol, and the like.

[0026] When the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 contains fibers composed of a polymer containing flame-retardant monomer components, the main skeleton of the polymer can be, for example, a polyester skeleton, a polyolefin skeleton, etc., but a polyester skeleton is preferred.

[0027] Furthermore, the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 may be a long-fiber nonwoven fabric to which a flame retardant has been applied.

[0028] This allows for the use of various commercially available long-fiber nonwoven fabrics as the base material, and enables more favorable adjustment of the flame retardant content and the film thickness of the flame retardant-containing portion by adjusting the composition and viscosity of the coating solution.

[0029] When the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 is obtained by coating the surface of a long-fiber nonwoven fabric as a base material with a flame retardant, the flame-retardant long-fiber nonwoven fabric can be suitably manufactured, for example, by removing the solvent or dispersion medium after coating the long-fiber nonwoven fabric as a base material with a solution or dispersion of the flame retardant.

[0030] Furthermore, the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 may be formed from a mixture containing a resin material and a flame retardant.

[0031] This allows for more favorable adjustment of conditions such as the mixing ratio of resin material and flame retardant, and the width of the fibers. Furthermore, it is possible to improve the flame retardancy of the fibers themselves contained in the first base material A1, and to more effectively prevent unintentional shedding of flame retardant components from the fibers.

[0032] When the flame-retardant long-fiber nonwoven fabric constituting the first base material A1 is formed from a compound containing a resin material and a flame retardant, the resin material contained in the compound may include, for example, the following: The resin material contained in the compound may include, for example, polyolefins such as polyethylene and polypropylene, synthetic resins such as polyester and polyamide, and natural resin fibers such as cellulose, keratin, and fibroin. One or more selected from these can be used in combination, but polyester is particularly preferred.

[0033] Furthermore, as the flame retardant, for example, a compound having tautomerism, and a compound having a tautomer with a hydroxyl group, can be suitably used.

[0034] This makes it possible to improve the absorption performance of the liquid in contact with the liquid absorbent A100, especially when the liquid in contact with the absorbent A100 contains water, by making it more stable and superior over a long period of time.

[0035] Examples of the aforementioned tautomerisms include keto-enol tautomerism, amide-imido acid tautomerism, lactam-lactim tautomerism, nitroso-oxime tautomerism, nitro-acinitro tautomerism, nuclear tautomerism, valence tautomerism, and ring chain tautomerism.

[0036] Specific examples of compounds exhibiting tautomerism include cyanuric acid, triazine analogues, and organophosphorus compounds having a phosphorus-oxygen bond, specifically 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide.

[0037] The aforementioned tautomeristic compound preferably contains a nitrogen atom in its molecule. Nitrogen is an element that can directly contribute to the formation of hydrogen bonds and is also advantageous in improving flame retardancy. Therefore, the aforementioned effects are more pronounced.

[0038] The aforementioned flame retardant having tautomerism may be, for example, melamine cyanurate. Melamine cyanurate is a mixture containing cyanuric acid, a compound having tautomerism, and melamine, a compound that does not have tautomerism. Cyanuric acid has a structure containing three hydroxyl groups, but isocyanuric acid, a compound in which these hydroxyl groups are replaced with carbonyl groups by tautomerism, forms multiple hydrogen bonds with melamine in the mixture. Due to this structure, melamine cyanurate is extremely unresponsive to altered ink, and it is thought that the effects described above are exhibited more significantly as a result.

[0039] Furthermore, the flame retardant may be a compound other than the compound having tautomerism. Examples of compounds other than the aforementioned tautomers include hydrated metal salt compounds such as aluminum hydroxide, aluminum carbonate, magnesium hydroxide, magnesium carbonate, hanthite, hydromagnesite, calcium hydroxide, calcium carbonate, zinc sulfate, dihydrated gypsum, calcium aluminate, dawsonite, and kaolin clay; phosphate compounds containing amino and / or ammonium groups such as ammonium polyphosphate, guanidine phosphate, melamine polyphosphate, and guanylurea phosphate; nitrogen-phosphorus flame retardants obtained by adding a compound containing amino and / or ammonium groups to the phosphate compound; melamine; phosphazene derivatives; boric acid compounds such as Na2B4O7·10H2O; and superabsorbent resins such as crosslinked sodium polyacrylate. One or more of these can be selected and used in combination. Examples of commercially available superabsorbent polymers such as cross-linked sodium polyacrylate include Aquaric from Nippon Shokubai Chemicals, DiaWet from Mitsubishi Chemical Corporation, Aronzap from Toagosei Co., Ltd., AquaReserve GP from Nippon Gosei Co., Ltd., Sumikagel from Sumitomo Chemical Co., Ltd., Sunwet from Sanyo Chemical Industries, Ltd., Arasorb from Arakawa Chemical Corporation, Drytech from Dow Chemical Corporation, Favor from Stockhausen AG, Bell Oasis from Kanebo Co., Ltd., and Fibersorb from Camelot.

[0040] When the flame retardant contains compounds other than the non-tautomer compound, along with the tautomer compound, the proportion of the tautomer compound in the flame retardant is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, and even more preferably 40.0% by mass or more and 99.0% by mass or less.

[0041] However, in this specification, the term "flame-retardant component" refers to the flame-retardant monomer components and flame retardants mentioned above.

[0042] The average width of the fibers constituting the flame-retardant long-fiber nonwoven fabric is not particularly limited, but 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.

[0043] The first base material A1 may include components other than a flame-retardant long-fiber nonwoven fabric. Examples of such components include binders that bind the fibers together.

[0044] As a binder, for example, a heat-sealable resin, which will be described later in [1-3-2], can be used.

[0045] However, the content of components other than the flame-retardant long-fiber nonwoven fabric in the first base material A1 is preferably 10.0% by mass or less, more preferably 7.0% by mass or less, and even more preferably 5.0% by mass or less.

[0046] The basis weight of the first base material A1 is not particularly limited, but is 5.0 g / m². 2 More than 70.0g / m 2 Preferably, it is 7.0 g / m 2 More than 60.0g / m 2 It is more preferable that it be less than 10.0 g / m 2 More than 50.0g / m 2 The following is even more preferable:

[0047] This makes it possible to improve the liquid permeability of the first substrate A1 while also improving the shape stability and durability of the liquid absorbent A100.

[0048] The thickness of the first substrate A1 is preferably 0.01 mm or more and 3 mm or less, and more preferably 0.05 mm or more and 1 mm or less.

[0049] This makes it possible to improve the liquid permeability of the first substrate A1 while also improving the shape stability and durability of the liquid absorbent A100. Furthermore, it is possible to increase the amount of liquid that can be absorbed per unit volume of the liquid absorbent A100 while suppressing an increase in the manufacturing cost of the liquid absorbent A100.

[0050] [1-2]Second base material The second substrate A2, together with the first substrate A1, sandwiches the absorbent layer A3. The second base material A2 contains a flame-retardant long-fiber nonwoven fabric.

[0051] The second base material A2 is usually in the form of a sheet. The second base material A2 can be anything that is permeable to liquids, but it usually contains fibers.

[0052] The second base material A2 is preferably subject to the same conditions as described in [1-1] above, but the first base material A1 and the second base material A2 may be subject to the same conditions or to different conditions.

[0053] [1-3] Absorption layer The absorption layer A3 is located between the first substrate A1 and the second substrate A2, and is primarily responsible for absorbing liquids.

[0054] The flame retardant content in absorbent layer A3 is less than 10% by mass. This sufficiently low flame retardant content in absorbent layer A3 ensures that the formation of aggregates when liquid comes into contact with the liquid absorbent A100 can be stably prevented over a long period of time.

[0055] As described above, the flame retardant content in the absorbent layer A3 may be less than 10% by mass, but is preferably less than 7% by mass, more preferably less than 4% by mass, and even more preferably less than 2% by mass. This allows the effects of the present invention, as described above, to be exhibited more clearly.

[0056] [1-3-1] Fibers The absorbent layer A3 may be composed of any material that has the function of absorbing liquid, but it is preferable that it contains fibers.

[0057] This allows for more efficient absorption of the liquid through capillary action, and enables the liquid to be more effectively retained in the absorption layer A3.

[0058] Examples of fibers constituting the absorbent layer A3 include polyolefin fibers such as polyethylene and polypropylene, synthetic resin fibers such as polyester fibers and polyamide fibers, and natural resin fibers such as cellulose fibers, keratin fibers, and fibroin fibers. These fibers may also have chemical structures that impart flame retardancy, such as phosphophenanthrene rings, introduced into them, but cellulose fibers are preferred among them.

[0059] Because cellulose fibers are hydrophilic materials, for example, when a liquid containing water is applied to the liquid absorber A100, they become compatible with the liquid and can more effectively retain it. Furthermore, cellulose fibers are a renewable natural material and are inexpensive and readily available compared to other types of fibers, making them advantageous from the standpoint of reducing production costs, ensuring stable production, and reducing environmental impact.

[0060] In this specification, cellulose fiber refers to any material that is fibrous and mainly consists of cellulose as a compound, and may also contain, for example, hemicellulose or lignin in addition to cellulose.

[0061] As cellulose fibers, for example, papermaking wood pulp such as chemical pulp and mechanical pulp prepared from coniferous and / or hardwood wood, recycled paper pulp, linters, and non-wood plant fibers prepared from hemp, cotton, kenaf, etc. can be used.

[0062] The average length of the fibers constituting the absorbent layer A3 is not particularly limited, but is preferably 0.1 mm or more and 50 mm or less, more preferably 0.5 mm or more and 30 mm or less, and even more preferably 1.0 mm or more and 5.0 mm or less.

[0063] This allows for improved liquid absorption and retention capabilities of the absorbent layer A3. Furthermore, for example, recycled paper or other defibrated materials can be suitably used as the fibers constituting the absorbent layer A3, which is advantageous from the viewpoint of reducing the production cost of the liquid absorbent A100 and promoting resource reuse.

[0064] The average width of the fibers constituting the absorbent layer A3 is not particularly limited, but 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.

[0065] The fiber content in absorbent layer A3 is preferably 65.0% by mass or more and 99.0% by mass or less, more preferably 72.0% by mass or more and 98.0% by mass or less, and even more preferably 78.0% by mass or more and 97.0% by mass or less.

[0066] This allows for improved long-term, stable liquid absorption performance of the liquid absorbent A100. It also offers advantages in terms of reducing the manufacturing cost of the liquid absorbent A100.

[0067] [1-3-2] Heat-fusible resin The absorbent layer A3 may contain a heat-sealable resin.

[0068] This allows for the effective bonding of the constituent materials of the absorbent layer A3, such as the aforementioned fibers, and more effectively prevents, for example, the unintentional detachment of the constituent materials of the absorbent layer A3 from the liquid absorbent body A100, thereby improving the stability of the shape of the liquid absorbent body A100. In particular, the above effects can be obtained even when short fiber lengths are used as the fibers constituting the absorbent layer A3. Therefore, for example, defibrated materials such as recycled paper can be suitably used as the fibers constituting the absorbent layer A3, which is advantageous from the viewpoint of reducing the production cost of the liquid absorbent body A100 and recycling resources.

[0069] Examples of heat-sealable resins include polyolefin resins such as polyethylene, polypropylene, polyvinyl acetate, ethylene-vinyl acetate copolymer, and polyvinyl alcohol; polyamides; polyesters; and polyurethanes.

[0070] Furthermore, the heat-sealable resin may have multiple regions composed of different materials, for example. More specifically, it may have a structure in which a base made of a high-melting-point material such as polypropylene with a melting point of about 160°C is covered with a coating layer made of a low-melting-point material such as polyethylene with a melting point of about 130°C. With such a structure, for example, during the manufacture of the liquid absorber A100, by performing heat treatment at a temperature in which the outer coating layer melts or softens but the base does not, only the coating layer can be melted or softened, thereby making the productivity of the liquid absorber A100 particularly excellent and the shape stability of the liquid absorber A100 particularly excellent.

[0071] The content of the heat-fusible resin in the absorbent layer A3 is preferably 1.0% by mass or more and 30.0% by mass or less, more preferably 2.0% by mass or more and 25.0% by mass or less, and even more preferably 3.0% by mass or more and 20.0% by mass or less.

[0072] This allows for a sufficiently high fiber content while fully utilizing the effects of the heat-fusible resin, thereby improving the long-term stable liquid absorption performance of liquid absorbent A100. It also offers advantages in terms of reducing the manufacturing cost of liquid absorbent A100.

[0073] In particular, it is preferable that the absorbent layer A3 contains cellulose fibers and a heat-fusible resin. This makes the aforementioned effects even more pronounced.

[0074] [1-3-3] Flame retardant As mentioned above, the absorbent layer A3 may contain a flame retardant if it is present in a sufficiently low amount of less than 10% by mass.

[0075] This makes it possible to improve the overall flame retardancy of the liquid absorbent A100.

[0076] As the flame retardant contained in the absorbent layer A3, for example, those listed in [1-1] above can be used, but the absorbent layer A3 may also contain hydroxide as a flame retardant, for example.

[0077] This improves the overall flame retardancy of the liquid absorber A100, and even if the liquid is oxidized by air or other factors, the neutralization reaction with hydroxides allows the liquid absorbed by the absorbent layer A3 to have a relatively high pH value, for example, a neutral to basic pH value, thereby more effectively preventing the formation of aggregates.

[0078] If the absorbent layer A3 contains a hydroxide as a flame retardant, it is preferable that the hydroxide has low solubility in liquids, such as aluminum hydroxide.

[0079] This makes it possible to more reliably prevent the leaching of hydroxides and more effectively prevent the liquid absorbed in absorption layer A3 from becoming excessively basic.

[0080] The flame retardant contained in absorbent layer A3 may be in any form, but is preferably in powder form. If the flame retardant is in powder form, the average particle size of the flame retardant is preferably 0.1 μm or more and 20.0 μm or less, and more preferably 1.0 μm or more and 10.0 μm or less.

[0081] In this specification, the average particle size refers to the average particle size based on volume. The average particle size can be determined by measurement using a particle size distribution analyzer that uses the laser diffraction / scattering method as its measurement principle, such as the LA910 manufactured by Horiba, Ltd., i.e., a laser diffraction particle size distribution analyzer.

[0082] [1-3-4] Other ingredients The absorbent layer A3 may contain components other than those described above. Hereinafter, such components are also referred to as "other components". Examples of other components include colorants, anti-aggregation agents, surfactants, defoamers, moisturizers, preservatives, pH adjusters, antistatic agents, and the like. Further, the absorbent layer A3 may contain, as other components, resin materials other than heat-sealable resins such as photocurable resins, water-absorbing resins, and ion-exchange resins, for example. <0

[0083] The content of other components in the absorbent layer A3 is preferably 10.0% by mass or less, more preferably 7.0% by mass or less, and even more preferably 5.0% by mass or less.

[0084] [1-3-5] Other conditions The basis weight of the absorbent layer A3 is not particularly limited, but is preferably 150 g / m 2 or more and 2000 g / m 2 or less, more preferably 500 g / m 2 or more and 1000 g / m 2 or less.

[0085] Thereby, the liquid absorption and retention ability of the absorbent layer A3 can be made more excellent.

[0086] The thickness of the absorbent layer A3 is preferably 2 mm or more and 50 mm or less, more preferably 5 mm or more and 20 mm or less.

[0087] Thereby, while making the handling of the liquid absorber A100 sufficiently excellent, the amount of liquid that can be absorbed by the liquid absorber A100 can be increased.

[0088] [1-4] Others When the liquid absorber A100 contains cellulose fibers, the liquid absorber A100 may contain cellulose fibers derived from waste paper as the cellulose fibers. Thereby, it is possible to contribute to resource saving and energy saving, and it is also preferable from the viewpoint of environmental protection.

[0089] When the liquid absorbent A100 contains cellulose fibers, the proportion of recycled paper-derived cellulose fibers in the total cellulose fibers constituting the liquid absorbent A100 is preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less. This allows the effects of including recycled paper-derived cellulose fibers as described above to be fully realized, while also making the overall liquid absorbency of the liquid absorbent A100 particularly excellent.

[0090] The liquid absorbed by the liquid absorber A100 preferably contains water. The problem of aggregate formation described above was particularly likely to occur when the liquid absorbed by the liquid absorbent contained water. However, according to the present invention, even when the liquid absorbed by the liquid absorbent contains water, the occurrence of the above-mentioned problem can be effectively prevented. In other words, the effects of the present invention are more pronounced when the liquid absorbent A100 absorbs water. Furthermore, since many applications of liquid absorbents involve the absorption of liquids containing water, the versatility of the liquid absorbent becomes even greater.

[0091] When the liquid absorbed by the liquid absorber A100 contains water, the water content in the liquid absorbed by the liquid absorber A100 is preferably 5% by mass or more and 97% by mass or less, more preferably 10% by mass or more and 95% by mass or less, even more preferably 20% by mass or more and 93% by mass or less, and most preferably 30% by mass or more and 90% by mass or less. This allows the effects of the present invention described above to be exhibited more clearly.

[0092] The solid content in the liquid absorbed by the liquid absorbent A100 is preferably 2% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 45% by mass or less, and even more preferably 5% by mass or more and 40% by mass or less. This allows the effects of the present invention described above to be exhibited more clearly.

[0093] The liquid absorbent A100 may have a first substrate A1, a second substrate A2, and an absorbent layer A3 as described above, but may also have other configurations. For example, a bonding layer may be provided between the first substrate A1 and the absorbent layer A3, or between the second substrate A2 and the absorbent layer A3 to join them. In such cases, the bonding layer may be made of, for example, an adhesive. Also, for example, the liquid absorbent of the present invention may have, in addition to the two substrates described above, namely the first substrate and the second substrate and at least one absorbent layer provided between them, it may also have other substrates and other absorbent layers. In other words, for example, the liquid absorbent of the present invention may have three or more substrates and two or more absorbent layers, and may have a structure in which these substrates and absorbent layers are arranged alternately.

[0094] The shape of the liquid absorbent A100 is not particularly limited, but a sheet-like shape is preferred.

[0095] The liquid absorbent of the present invention may be used individually or in multiple units simultaneously. More specifically, for example, a single liquid absorbent A100 may be housed in a predetermined container, or multiple liquid absorbents A100 may be housed in a predetermined container.

[0096] When using multiple liquid absorbents A100 simultaneously, for example, multiple sheet-shaped liquid absorbents A100 may be stacked on top of each other in a predetermined positional relationship. Alternatively, multiple small pieces of liquid absorbents A100 may be filled into a predetermined container and used.

[0097] Liquid absorbent A100 can be used for any purpose as long as it is used to absorb liquids, but it is preferable that it is used to absorb ink.

[0098] Ink has been particularly difficult to use with liquid absorbents to maintain the absorption performance of the absorbent over a long period of time, even among the various liquids that can be used with liquid absorbents. In contrast, the present invention can effectively prevent the occurrence of the above-mentioned problems even when the liquid absorbent is used to absorb ink. In other words, the effects of the present invention are more pronounced when the liquid absorbent is used to absorb ink.

[0099] Examples of inks include pigment inks containing pigments, dye inks containing dyes, and clear inks that do not contain pigments or dyes, but it is preferable that the liquid absorber A100 is used to absorb pigment ink.

[0100] In liquid absorbers used with pigment inks, which contain dispersed pigment particles, changes in pH can easily cause pigment aggregates to fill the gaps in the liquid absorber, making it difficult to maintain the ink's absorption performance over the long term. In contrast, the present invention effectively prevents the occurrence of the above-mentioned problems even when the liquid absorber is used to absorb pigment ink.

[0101] [2] Method for manufacturing a liquid absorbent Next, a preferred method for manufacturing the liquid absorbent A100 will be described.

[0102] Figure 2 is a schematic diagram illustrating a preferred embodiment of the apparatus used for manufacturing the liquid absorbent of the present invention.

[0103] In the following explanation, the aforementioned apparatus will be described using an example of a sheet manufacturing apparatus that produces a sheet corresponding to the absorbent layer of a liquid absorbent.

[0104] The sheet manufacturing device P100 manufactures sheets corresponding to the area that will become the absorbent layer A3.

[0105] As shown in Figure 2, the sheet manufacturing apparatus P100 includes a fiber supply means P1 for supplying a fiber source, a defibration means P2 for defibrating the supplied fiber source, a heat-fusible resin supply means P3 for supplying a heat-fusible resin, a molding means P4 for molding a mixture containing the fiber and heat-fusible resin into a predetermined shape, and a cutting means P5 for cutting the molded body produced by the molding means P4.

[0106] The fiber supply means P1 includes a quantitative feeder that quantifies the fiber source and supplies it to the defibration means P2. For example, recycled paper containing cellulose fibers can be suitably used as the fiber source. The defibration means P2 has the function of defibrating the fiber source into predetermined sizes.

[0107] The heat-fusible resin supply means P3 is equipped with a quantitative feeder that supplies a fixed amount of heat-fusible resin. This allows for optimal adjustment of the mixing ratio of heat-fusible resin to fibers.

[0108] The molding means P4 includes a mixing section P41 for uniformly mixing the fibers and the heat-fusible resin by stirring, a molding section P42 for forming it into a sheet, and a fixing section P43 for melting or softening at least a portion of the heat-fusible resin and fixing each component by pressurizing and heating.

[0109] In the mixing section P41, a stirring gas is introduced to mix the various components. This allows for more uniform mixing and more efficient mixing.

[0110] In the molding section P42, the mixture applied to the breathable conveying means P6 is sucked through the conveying means P6, thereby making the mixture adhere to the conveying means P6 and forming it into a sheet.

[0111] In the immobilization section P43, at least a portion of the heat-sealable resin is melted or softened by heating and pressurizing under predetermined conditions, thereby fixing each component. This makes it possible to obtain a molded body with excellent shape stability.

[0112] The pressurization treatment at the immobilization section P43 is preferably carried out at a temperature of 100°C to 250°C, with a pressure of 1000 Pa to 8000 Pa and a duration of 30 seconds to 120 seconds.

[0113] This makes it possible to achieve particularly excellent liquid absorption and flame retardancy for the liquid absorbent A100.

[0114] As described above, the processing temperature during pressurization in the immobilization section P43 is preferably 100°C to 250°C, more preferably 190°C to 240°C, and even more preferably 200°C to 230°C. This allows the effects described above to be exhibited more dramatically.

[0115] Furthermore, as described above, the pressurized pressure at the immobilization section P43 is preferably 1000 Pa or more and 8000 Pa or less, more preferably 3000 Pa or more and 6000 Pa or less, and even more preferably 4000 Pa or more and 5000 Pa or less. This allows the effects described above to be exhibited more dramatically.

[0116] Furthermore, as described above, the processing time for pressurization in the immobilization section P43 is preferably 30 seconds or more and 120 seconds or less, more preferably 40 seconds or more and 110 seconds or less, and even more preferably 50 seconds or more and 100 seconds or less. This allows the effects described above to be exhibited more dramatically.

[0117] Downstream of the molding means P4, a cutting means P5 is positioned to cut the sheet S, which is a molded body produced by the molding means P4. Cutting by the cutting means P5 yields a sheet S of the desired size.

[0118] Subsequently, the obtained sheet S is sandwiched between a first base material A1 and a second base material A2, which are prepared separately, and these are joined together to obtain a liquid absorbent A100.

[0119] For the first base material A1 and the second base material A2, for example, commercially available flame-retardant long-fiber nonwoven fabric may be used, or a long-fiber nonwoven fabric used as a base material may have a flame retardant applied to its surface by a coating method, or a mixture containing a resin material and a flame retardant may be molded by a method such as the spunbond method or the spunlace method.

[0120] Alternatively, the first substrate A1 may be placed on the conveying means P6, the mixture may be deposited on top of it, the second substrate A2 may be deposited on top of that, and then heating and pressurizing may be performed in the fixing section P43.

[0121] [3] Printing device Next, the printing apparatus of the present invention will be described.

[0122] The printing apparatus of the present invention is equipped with the liquid absorbent of the present invention as described above. This makes it possible to provide a printing apparatus equipped with a liquid absorbent that has excellent flame retardancy and can maintain excellent liquid absorption performance stably over a long period of time.

[0123] Hereinafter, preferred embodiments of the printing apparatus of the present invention will be described in detail with reference to the attached drawings.

[0124] Figure 3 is an external perspective view showing the overall configuration of an example of an inkjet printer, which is a printing device. Figure 4 is an overall perspective view of the ink cartridge provided in the inkjet printer shown in Figure 3. Figure 5 is an exploded perspective view of the ink cartridge shown in Figure 4. Figure 6 is a longitudinal cross-sectional view of the ink cartridge shown in Figure 4. Figure 7 is an enlarged cross-sectional view of the main part of the ink cartridge shown in Figure 4. Figure 8 is a cross-sectional view illustrating the opening and closing operation of the on-off valve shown in Figure 6, where (a) is a cross-sectional view showing the on-off valve in a closed state, (b) is a cross-sectional view showing the on-off valve in an open state due to the pressure rise in the storage space caused by the introduction of waste ink, and (c) is a cross-sectional view showing the on-off valve closed again after the introduction of waste ink has finished.

[0125] The inkjet printer 1 uses multiple types of ink to print in color on roll paper. As shown in Figure 3, the front of the printer case 2, which encloses the printer body, is equipped with a roll paper cover 5 and an ink cartridge cover 7 that can be opened and closed. Furthermore, the front of the printer case 2 also houses a power switch 3, a feed switch, indicators, and other controls.

[0126] As shown in Figure 3, when the roll paper cover 5 is opened, the paper storage section 8, which houses the roll paper 6, becomes open, allowing the paper to be replaced. Also, when the ink cartridge cover 7 is opened, the cartridge mounting section 9 becomes open, allowing the ink cartridge 10 to be attached to and removed from the cartridge mounting section 9.

[0127] In the inkjet printer 1, the ink cartridge 10 is pulled out a predetermined distance forward of the cartridge mounting section 9 in conjunction with the operation of opening the ink cartridge cover 7.

[0128] As shown in Figures 4 to 6, the ink cartridge 10 is installed in the cartridge mounting section 9 of the inkjet printer 1. The cartridge case 15, which houses three ink packs 11, 12, and 13, is equipped with a waste ink storage structure 17 that stores waste ink generated during the printer's ink filling and head cleaning operations.

[0129] The three ink packs 11, 12, and 13 are each filled with a different color ink for color printing. Each ink pack 11, 12, and 13 has a similar structure, comprising a flexible bag 21 for containing the ink and an ink outlet 23 joined to the front end of the bag 21.

[0130] The bag body 21 is formed by overlapping two aluminum laminate films and joining their edges by methods such as heat sealing. The reason for using aluminum laminate films is to improve gas barrier properties. As for the aluminum laminate films, for example, a structure is used in which an aluminum foil is sandwiched between a nylon film on the outside and a polyethylene film on the inside.

[0131] As shown in Figure 6, the ink outlet 23 comprises a cylindrical body 23a whose base end outer diameter is larger than that of the tip end and which is fixed to the bag body 21, a valve body 23b installed inside the cylindrical body 23a to open and close the flow path of the cylindrical body 23a, and a sealing film 23c attached to the tip of the cylindrical body 23a to seal the opening of the cylindrical body 23a. The cylindrical body 23a of the ink outlet 23 is made of, for example, hard plastic. The sealing film 23c is made of polyethylene film.

[0132] The ink outlet 23 is integrated with the cylindrical body 23a by fixing the base end of the cylindrical body 23a to the aluminum laminate film of the bag body 21 by heat fusion or the like.

[0133] As shown in Figures 5 and 6, the cartridge case 15 comprises an upper case 31, a lower case 33 connected below the upper case 31, and an intermediate container wall 35 that divides the space formed by the upper case 31 and the lower case 33 vertically.

[0134] The upper case 31 and lower case 33 are molded products made of plastic material, and the intermediate container wall 35 is formed of a flexible sheet material, which is a plastic film.

[0135] The upper case 31 is box-shaped with an open bottom, and the front container wall 31a is shorter than the side and rear container walls. At the lower end of this front container wall 31a, a semi-cylindrical ink pack positioning section 31b is formed to position the upper half of the ink outlet 23 of the ink packs 11, 12, and 13. A total of three semi-cylindrical ink pack positioning sections 31b are formed to accommodate the three ink packs 11, 12, and 13 that are housed within.

[0136] Furthermore, at the lower end of the side walls 31c, which are the container walls on both sides of the upper case 31, and near the rear end, there are locking projections 31d that engage with the engaging portion 33a on the lower case 33 to connect the upper and lower cases together.

[0137] The lower case 33 is a thin, dish-shaped box with an open top. The front container wall 33b is set to be taller than the container walls on both sides and the rear, and a semi-cylindrical ink pack positioning section 33c is formed at the upper end of this front container wall 33b to position the lower half of the ink outlet 23 of the ink packs 11, 12, and 13.

[0138] As shown in Figure 6, the semi-cylindrical ink pack positioning section 33c positions and fixes the ink outlet 23 of the ink packs 11, 12, and 13 by sandwiching the ink outlet 23 from above and below with the ink pack positioning section 31b of the upper case 31. Similar to the ink pack positioning section 31b described above, this semi-cylindrical ink pack positioning section 33c is also formed in a total of three locations to accommodate the three ink packs 11, 12, and 13.

[0139] Furthermore, a cover portion 33d is formed at the upper end of the front container wall 33b, extending from the front end of the ink pack positioning portion 33c and covering the front of the ink outlet 23. As shown in Figure 6, an opening 33e is formed through this cover portion 33d for inserting the ink supply needle 41 equipped in the cartridge mounting portion 9 of the inkjet printer 1.

[0140] Three openings 33e are formed, with their centers aligned with each of the three semi-cylindrical ink pack positioning sections 33c.

[0141] When the ink cartridge 10 is installed in the cartridge mounting section 9 of the inkjet printer 1, the ink supply needle 41 equipped in the cartridge mounting section 9 airtightly penetrates the ink outlet 23, and the ink in the bag 21 can be supplied to the printer via the ink supply needle 41. A supply tube 42 for supplying ink to the printer's print head is connected to the ink supply needle 41.

[0142] Furthermore, an inlet 44, which constitutes the waste ink introduction section 37 of the waste ink storage structure 17, is formed near the lower part of the front container wall 33b.

[0143] As shown in Figures 5 and 6, the waste ink introduction section 37 includes a tapered tubular rubber mouth member 37a whose inner diameter widens towards the tip, a sealing film 37b attached to the tip of the rubber mouth member 37a, a valve body 37c that contacts the rear end of the rubber mouth member 37a to close the opening of the rubber mouth member 37a, and a compression coil spring 37d that biases the valve body 37c in the direction of contacting the rubber mouth member 37a.

[0144] The inlet 44 is equipped with a projection at its foremost opening edge that locks the front end of the rubber mouth member 37a to prevent it from coming loose. The compression coil spring 37d brings the valve body 37c into contact with the rear end of the rubber mouth member 37a, and at the same time biases the rubber mouth member 37a forward, holding the front end of the rubber mouth member 37a in close contact with the projection at the foremost end of the inlet 44.

[0145] When the ink cartridge 10 is installed in the cartridge mounting section 9 of the inkjet printer 1, the waste ink introduction needle 47 equipped in the cartridge mounting section 9 fits airtightly into the rubber mouth member 37a and simultaneously pushes in the valve body 37c, allowing waste ink to be introduced into the storage space 51 via the waste ink introduction needle 47.

[0146] A waste ink guide tube 49 is connected to the waste ink introduction needle 47, which guides waste ink generated by the inkjet printer 1 during ink filling and head cleaning operations to the waste ink introduction needle 47.

[0147] As shown in Figures 4 and 5, the side container wall 33f of the lower case 33 is equipped with an IC module 53 that can record the type of each ink pack 11, 12, and 13 contained, the remaining ink level, and other various data.

[0148] When the ink cartridge 10 is inserted into the cartridge mounting section 9 of the inkjet printer 1, the IC module 53 is electrically connected to the connection terminals equipped in the cartridge mounting section 9. This allows the printer's control circuit or the computer to which the printer is connected to to read and write various information.

[0149] The intermediate container wall 35, which is a container wall formed from a flexible sheet material such as polyethylene film, is fixed to the lower case 33 in a slightly taut state by overlapping its peripheral edge with the upper end surfaces of the side container wall 33f and front and rear container walls 33g, 33h of the lower case 33 and joining the overlapped portion by a method such as heat fusion.

[0150] As the intermediate container wall 35 is fixed to the lower case 33 so as to cover the upper end opening of the lower case 33, a storage space 51 constituting the waste ink storage structure 17 is partitioned between the bottom wall 33i of the lower case 33 and the intermediate container wall 35, as shown in Figure 6. In addition, an ink pack storage space 55 is partitioned between the ceiling wall 31e of the upper case 31 and the intermediate container wall 35, which accommodates the three ink packs 11, 12, and 13 in an upright position as shown in Figure 5.

[0151] As shown in Figure 7, the ink packs 11, 12, and 13 are housed so that their lower ends abut against the intermediate container wall 35, and the weight of the ink packs 11, 12, and 13 biases the intermediate container wall 35 downward, as indicated by the arrow (A) in the figure.

[0152] Therefore, the force exerted by the ink packs 11, 12, and 13 to press the intermediate container wall 35 downward can also function as a biasing force to maintain the closed position of the on-off valve 65 of the waste ink storage structure 17, which will be described later. In this case, the intermediate container wall 35 can also be fixed to the lower case 33 without applying tension.

[0153] As shown in Figure 6, the waste ink storage structure 17 of this embodiment includes a storage space 51 for storing waste ink, which is partitioned by a lower case 33 and an intermediate container wall 35; a waste ink introduction section 37 for introducing waste ink into the storage space 51; a ventilation hole 61 for connecting the storage space 51 to the outside; two ink absorbent materials 63 as liquid absorbers that are loaded into the storage space 51 and permeate and absorb the waste ink introduced into the storage space 51 from the waste ink introduction section 37; and an on / off valve 65 for opening and closing the ventilation hole 61.

[0154] As shown in Figures 5 and 6, the waste ink introduction section 37, which introduces waste ink into the storage space 51, is provided at an inlet 44 formed in the front container wall 33b, which is part of the container wall that partitions the storage space 51.

[0155] As shown in Figure 6, the rear end of the inlet 44, that is, the left end in Figure 6, is in communication with the storage space 51, and the waste ink introduced from the waste ink introduction needle 47 inserted into the waste ink introduction section 37 flows into the storage space 51 from the rear end of the inlet 44.

[0156] The ventilation holes 61 formed in the intermediate container wall 35 are circular openings that open the storage space 51 to the atmosphere, and it is desirable that the location where these ventilation holes 61 are formed is the last location in the storage space 51 to reach the waste ink. In this embodiment, as shown in Figure 5, the ventilation holes 61 are provided at a location that does not interfere with the lower ends of the ink packs 11, 12, and 13, and is located near the rear end, away from the waste ink introduction section 37.

[0157] The ink absorbent 63 is made of the liquid absorbent material of the present invention described above, and absorbs the introduced waste ink so that the waste ink introduced into the storage space 51 via the waste ink introduction section 37 and the introduction port 44 does not flow back to the waste ink introduction section 37 and leak to the outside.

[0158] The on / off valve 65 provided in the vent hole 61 opens the vent hole 61 only when waste ink is being introduced, so as not to obstruct the introduction of waste ink from the waste ink introduction section 37, and releases the air in the storage space 51 to the outside.

[0159] In this embodiment, the plastic film used for the intermediate container wall 35 equipped with ventilation holes 61 is selected to be a plastic film that has enough flexibility to expand upward due to the pressure of waste ink introduced from the waste ink introduction section 37.

[0160] Furthermore, in this embodiment, as shown in Figure 8, the on / off valve 65 has an intermediate container wall 35 equipped with a ventilation hole 61, and a valve structural member 67 provided in the storage space 51 such that its tip abuts against the periphery of the ventilation hole 61 and closes the ventilation hole 61.

[0161] The valve structural member 67, which is a roughly cylindrical support column, has a positioning projection 67a protruding from its tip and penetrating the ventilation hole 61, and a stepped surface 67b that widens from the base of the positioning projection 67a and abuts against the opening periphery of the ventilation hole 61, and is integrally formed with the bottom wall 33i of the lower case 33 facing the ventilation hole 61. Therefore, the two ink absorbent materials 63 loaded into the storage space 51 have holes 63a formed through them for inserting the valve structural member 67.

[0162] As shown in Figure 8(a), the on / off valve 65 has a stepped surface 67b of the valve structural member 67 that abuts against the periphery of the vent hole 61, blocking the vent hole 61, and is kept closed except when waste ink is introduced from the waste ink introduction section 37.

[0163] As shown in Figure 8(b), when the pressure in the storage space 51 increases due to the introduction of waste ink, the intermediate container wall 35 deforms and expands upward. As a result, the periphery of the vent hole 61 separates from the stepped surface 67b of the valve structural member 67, and the on-off valve 65 opens the storage space 51 to the atmosphere through the vent hole 61.

[0164] Then, as shown in Figure 8(c), when the introduction of waste ink is completed and the pressure in the storage space 51 decreases, the venting valve 65 is biased in a direction in which the periphery of the vent hole 61 comes into contact with the stepped surface 67b of the valve structural member 67 by the tension of the intermediate container wall 35 itself and the ink packs 11, 12, and 13 that push the intermediate container wall 35 downward, so that the vent hole 61 is closed.

[0165] According to the waste ink storage structure 17 of this embodiment described above, the vent hole 61 that opens the storage space 51 to the atmosphere is kept closed by the on / off valve 65 except when waste ink is being introduced from the waste ink introduction section 37.

[0166] Therefore, by suppressing the evaporation of moisture from the waste ink introduced into the storage space 51 to the outside through the ventilation holes 61, it is possible to prevent the solidification of waste ink in the storage space 51, and thus prevent a decrease in the penetration absorption performance of the ink absorbent material 63 due to the solidification of waste ink. Furthermore, as described above, the liquid absorbent of the present invention itself has excellent liquid absorption performance, and this absorption performance can be stably maintained over a long period of time. For this reason, the above effects work synergistically, and in an inkjet printer 1 equipped with a waste ink storage structure 17 that includes an ink absorbent material 63 to which the liquid absorbent of the present invention is applied, stable penetration absorption performance can be maintained, especially over a long period of time. In addition, since clogging by solidified waste ink is effectively prevented, abnormal pressure increases are reliably prevented in the waste ink guide tube 49 on the waste ink supply side connected to the waste ink introduction section 37, and problems such as ink leakage due to the waste ink guide tube 49 coming off can also be reliably prevented.

[0167] Furthermore, in the waste ink storage structure 17 of this embodiment, for example, when disposing of a used ink cartridge 10, after separating the upper case 31 and the lower case 33, the intermediate container wall 35 made of plastic film can be peeled off from the lower case 33, thereby opening up one side of the storage space 51. As a result, the ink absorbent material 63 that has been permeated with waste ink can be easily removed from the storage space 51. Consequently, it becomes easier to disassemble the used ink cartridge 10 for recycling and reuse of parts and materials and to classify them by material. In addition, as described above, the liquid absorbent material of the present invention has excellent liquid absorption performance, and this absorption performance can be stably maintained over a long period of time. For this reason, in an inkjet printer 1 equipped with an ink absorbent material 63 to which the liquid absorbent material of the present invention is applied, when removing the ink absorbent material 63 that has been permeated with waste ink from the storage space 51, it is reliably prevented that the ink components will not fall off the ink absorbent material 63.

[0168] Furthermore, by integrally forming a valve structural member 67 on the bottom wall 33i opposite the ventilation hole 61 formed through the intermediate container wall 35 made of plastic film, with its tip contacting the periphery of the ventilation hole 61 to close the ventilation hole 61, an on-off valve 65 for opening and closing the ventilation hole 61 can be obtained. Therefore, no additional parts are required to equip the on-off valve, and no cost increase due to an increase in the number of components or an increase in the parts assembly process is incurred.

[0169] Furthermore, in the ink cartridge 10 of the above embodiment, the intermediate container wall 35, which is provided with ventilation holes 61, partitions the ink pack storage space 55 that houses the ink packs 11, 12, and 13, and the storage space 51.

[0170] Therefore, since the ventilation holes 61 are not directly exposed to the outside of the ink cartridge 10, but are opened to the atmosphere via the ink pack storage space 55 that houses the ink packs 11, 12, and 13, there is no risk of the user inadvertently touching the on / off valve 65 provided in the ventilation holes 61 and causing damage to the valve function.

[0171] Furthermore, a positioning projection 67a is provided at the tip of the valve structural member 67 in this embodiment, which penetrates the ventilation hole 61.

[0172] Therefore, alignment between the tip of the valve structural member 67 and the ventilation hole 61 of the intermediate container wall 35 becomes easier during assembly, improving ease of assembly.

[0173] The specific structure of an ink cartridge equipped with a waste ink storage structure is not limited to the ink cartridge 10 of the above embodiment. The waste ink storage structure described above can be applied to various ink cartridges with different ink pack support structures, the number of ink packs to be stored, etc.

[0174] Furthermore, the specific structure of the valve structural member is not limited to the configuration of the valve structural member 67 in the above embodiment. For example, the upper end surface of the valve structural member can be a thick plate-like rib structure that closes the ventilation hole 61.

[0175] Figure 9 is a schematic exploded perspective view showing the overall configuration of an inkjet printer, a printing device; Figure 10 is an exploded perspective view of the waste ink tank of the inkjet printer shown in Figure 9; Figure 11 is an enlarged cross-sectional view of the on-off valve provided in the waste ink tank shown in Figure 10; and Figure 12 is a longitudinal cross-sectional view showing another example of the on-off valve configuration.

[0176] As shown in Figure 9, the inkjet printer 101 of this embodiment comprises a printer housing 111, which is the bottom housing; a waste ink tank 120, which is rectangular in plan view and is detachably mounted in a tank housing 111s defined at the bottom of the bottom housing; a printer mechanism 115 installed above the printer housing 111 and the waste ink tank 120; and an outer cover 112, which is the upper housing. A power supply unit 116 is also mounted on the rear side of the tank housing 111s that houses the waste ink tank 120.

[0177] The waste ink tank 120 comprises a flat, box-shaped tank body 121 that replaceably houses multiple ink absorbent materials 122 for permeating and absorbing waste ink introduced into the storage space 151, and a lid 124 that seals the top opening of the tank body 121 via a sealing material 123 such as a rubber gasket. In particular, the configuration shown in Figure 10 includes four ink absorbent materials 122A, 122B, 122C, and 122D. Furthermore, a tube 125 is equipped on the underside of the lid 124 to guide waste ink from the ink receiving port 127 at the periphery of the tank to the center of the tank and drip it onto the upper center of the ink absorbent material 122. It is preferable that the plastic parts constituting the waste ink tank 120 be a dark color, such as black.

[0178] The waste ink tank 120 is fitted into the tank housing section 111s on the printer housing 111 and secured with screws. It can then be installed in the printer housing 111 by connecting the discharge port of the suction pump to the base inlet 125a of the tube 125. To remove it, the reverse operation is performed, allowing it to be detached independently from the printer housing 111.

[0179] The ink absorbent material 122 is configured as a laminate formed by stacking thin plate-shaped molded bodies to which the liquid absorbent material of the present invention is applied in multiple layers from the bottom layer to the top layer. In particular, in the illustrated configuration, the ink absorbent materials 122A, 122B, 122C, and 122D are stacked in four layers. Furthermore, a central hole 1221 is provided in the center of the plane of the upper three layers of ink absorbent materials 122B, 122C, and 122D, excluding the bottom layer ink absorbent material 122A, and a tube housing groove 1222 is formed in the top layer ink absorbent material 122D, extending from the periphery to the central hole 1221.

[0180] Then, the tube 125 is housed in the tube housing groove 1222 formed in the uppermost ink absorbent material 122D, with the base end inlet 125a of the tube 125 positioned in the ink receiving port 127 provided on the periphery of the lid 124, and the tip outlet 125b of the tube 125 positioned within the central hole 1221 of the uppermost ink absorbent material 122D.

[0181] In other words, the waste ink tank 120 of this embodiment has a waste ink storage structure in which a lid 124, which is a container wall that partitions a storage space 151 for storing waste ink generated during the ink filling operation and head cleaning operation of the printer, is provided with an ink receiving port 127, which is a waste ink introduction part for introducing waste ink into the storage space 151, and a ventilation hole 173 for opening the storage space 151 to the atmosphere.

[0182] Furthermore, as shown in Figure 11, a shut-off valve 171 is provided in the vent hole 173 formed in the lid 124, which opens only when waste ink is introduced. This shut-off valve 171 is integrally molded from an elastic member having a valve body 174 that closes the vent hole 173 formed in the lid 124, and an opening / closing portion 174c that elastically deforms in the direction of opening due to the pressure of waste ink introduced from the ink receptacle portion 127.

[0183] The valve body 174 is integrally formed from a rubber material and comprises a flange portion 174a that is tightly joined to the periphery of the vent hole 173, a cylindrical portion 174b that extends from the inner circumference of the flange portion 174a through the vent hole 173, and a plurality of opening and closing portions 174c formed by making axial cuts 174d in a conical portion connected to the tip of the cylindrical portion 174b so as to close the tip of the cylindrical portion 174b.

[0184] The opening / closing portion 174c of the opening / closing valve 171 is closed as shown in Figure 11(a) when no waste ink is introduced, but when waste ink is introduced, it elastically deforms in the opening direction due to the pressure of the waste ink introduced from the ink receptacle portion 127 as shown in Figure 11(b), and the notch 174d opens, allowing the air in the storage space 151 to escape to the outside.

[0185] Therefore, a dedicated valve body 174 is required to constitute the on-off valve 171. However, by appropriately setting the elastic properties of the on-off portion 174c of the valve body 174, the sealing performance of the vent hole 173 by the on-off valve 171 can be improved, thereby improving the performance in preventing moisture evaporation from the vent hole 173.

[0186] Furthermore, since the material of the lid 124, which has ventilation holes 173, is not limited, the design flexibility of the waste ink tank 120 equipped with a waste ink storage structure is improved.

[0187] According to the waste ink tank 120 of this embodiment described above, it is possible to prevent the solidification of waste ink in the storage space 151 by suppressing the evaporation of moisture in the waste ink introduced into the storage space 151 to the outside through the ventilation holes 173. Furthermore, as described above, the liquid absorbent of the present invention itself has excellent liquid absorption performance, and this absorption performance can be stably maintained over a long period of time. As a result, the above effects work synergistically, and in an inkjet printer 101 equipped with a waste ink tank 120 that includes an ink absorbent material 122 to which the liquid absorbent of the present invention is applied, stable penetration and absorption performance can be maintained, especially over a long period of time.

[0188] Furthermore, in this embodiment, the waste ink tank 120 of the inkjet printer 101 can be removed independently from the printer housing 111. This allows the ink-soaked waste ink tank 120 to be managed separately, while the clean printer housing 111 can be recycled or reused. Also, because the waste ink tank 120 is detachable, it is possible to replace only the waste ink tank 120 with a new one without soiling the hands of the worker, if necessary.

[0189] Furthermore, when the waste ink tank 120 of this embodiment is used and ready for disposal, it can be easily disassembled by opening the lid 124, removing the ink absorbent material 122 that has absorbed the waste ink from the tank body 121, and then removing the valve body 174, tube 125, etc. from the lid 124. Therefore, it becomes easier to disassemble the used waste ink tank 120 for recycling and reuse of parts and materials, and to classify them by material.

[0190] It goes without saying that the configuration of the on-off valve, in which a valve body having an opening / closing section that opens due to the pressure of waste ink introduced from the waste ink introduction section is integrally molded, is not limited to the configuration of the on-off valve 171 described above, and can take various forms.

[0191] The on-off valve 175 shown in Figure 12 comprises, for example, a substantially cylindrical valve seat 177 that is screwed and fixed into a vent hole in the wall of a container (not shown), and a valve body 178 that sits on the valve seat 177.

[0192] The valve seat 177 has a stepped surface 177a formed on the inner circumferential surface of the cylinder, which serves as the seating surface for the valve body 178. The valve body 178 is integrally molded from an elastic material and consists of a disc-shaped valve body 178a whose outer circumference seats on the stepped surface 177a, and a support portion 178b that supports the central part of the valve body 178a.

[0193] As shown by the dashed line in the figure, when waste ink is introduced, the outer circumference of the valve body 178a elastically deforms away from the valve seat 177 as the pressure on the storage space side rises, and as shown by the arrow in the figure, air from the storage space side can be released to the outside through the gap formed at that time.

[0194] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

[0195] For example, each component of a sheet manufacturing apparatus used to produce liquid absorbents can be replaced with any component capable of performing a similar function. Furthermore, any additional components may be added.

[0196] Furthermore, in the embodiments described above, the manufacturing apparatus was described as being equipped with a heat-fusible resin supply means for supplying the heat-fusible resin. However, when the absorbent layer is formed from a material containing fibers, a heat-fusible resin, and a flame retardant, the heat-fusible resin / flame retardant supply means may be provided instead of the heat-fusible resin supply means for supplying a mixture containing the heat-fusible resin and the flame retardant. Alternatively, the heat-fusible resin and the flame retardant may be supplied independently of each other, that is, the heat-fusible resin supply means and the flame retardant supply means may be provided separately. This allows, for example, the mixing ratio of the heat-fusible resin and the flame retardant to be suitably changed depending on the type of printing apparatus to which the liquid absorbent is applied, and thus suitable production of various types of liquid absorbents. Also, when forming an absorbent layer that does not contain heat-fusible resin, it is not necessary to supply the heat-fusible resin.

[0197] Furthermore, in the embodiments described above, a typical case was explained in which a sheet corresponding to the portion to be the absorption layer is cut, and then the sheet is sandwiched between the first and second substrates and joined together. However, the sheet may be joined to the first and second substrates before cutting.

[0198] Furthermore, while the above-described embodiment typically described a case where the first and second substrates are joined after manufacturing a sheet corresponding to the area to be the absorbent layer, for example, the sheet corresponding to the area to be the absorbent layer may be formed directly on the surface of the first or second substrate.

[0199] Furthermore, the liquid absorbent of the present invention is not limited to those manufactured using the apparatus described above, but may be manufactured using any apparatus.

[0200] Furthermore, the printing apparatus of the present invention may be any apparatus equipped with the liquid absorber of the present invention, and is not limited to those having the configuration described above.

[0201] Furthermore, each component of the printing apparatus of the present invention can be replaced with any other component capable of performing similar functions. Additionally, any additional components may be added. [Examples]

[0202] Next, specific embodiments of the present invention will be described. [4] Manufacturing of liquid absorbents The liquid absorbent was manufactured as follows:

[0203] (Example 1) First, we prepared a sheet manufacturing apparatus as shown in Figure 2.

[0204] The recycled paper, which served as a cellulose fiber source supplied from the fiber supply means of this sheet manufacturing apparatus, was defibrated using a defibration device, which served as a defibration means.

[0205] Next, a heat-fusible resin was supplied from a heat-fusible resin supply means to the transport path of the waste paper that had been defibrated by the defibration means, thereby obtaining a mixture of cellulose fibers and heat-fusible resin. As the heat-fusible resin, a polymer blend of polyester and polyethylene in a weight ratio of 50:50 was used.

[0206] Next, the above mixture was introduced into the mixing section of the molding means and further mixed with a stirring gas.

[0207] Next, this mixture was applied to a first substrate placed on a conveying means made of a breathable nonwoven fabric, and the mixture was made to adhere to the conveying means and formed into a sheet by suction through the conveying means.

[0208] The first and second base materials are both phosphophenancelene ring-containing polyester filament nonwoven fabrics obtained by the spunbond method (manufactured by Toyobo Co., Ltd., trade name Heim, basis weight 30 g / m²). 2 ) was used.

[0209] Next, a sheet-like molded material was introduced into the immobilization section and subjected to heating and pressurizing treatment under the conditions of a processing temperature of 220°C, a pressure of 4500 Pa, and a processing time of 90 seconds, thereby joining the materials together to obtain a liquid absorbent.

[0210] Subsequently, the liquid absorber was cut using an ultrasonic cutter as a cutting method to obtain small pieces of the liquid absorber.

[0211] The obtained liquid absorbent fragments were all rectangular parallelepipeds measuring 15 cm in length, 5 cm in width, and 10 mm in thickness, with a cellulose fiber content of 85% by mass and a heat-fusible resin content of 15% by mass.

[0212] (Example 2) A liquid absorbent was manufactured in the same manner as in Example 1, except that an apparatus equipped with a heat-fusible resin and flame retardant supply means was used instead of a heat-fusible resin supply means, and a mixture of the heat-fusible resin and flame retardant was supplied from the heat-fusible resin and flame retardant supply means. As the flame retardant, aluminum hydroxide with an average particle size of 8 μm was used.

[0213] (Example 3) A liquid absorbent was prepared in the same manner as in Example 2, except that 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide with an average particle size of 10 μm was used as the flame retardant instead of aluminum hydroxide.

[0214] (Example 4) A liquid absorbent was manufactured in the same manner as in Example 1, except that the first and second base materials were manufactured as described below.

[0215] Specifically, first, as a base material that does not contain flame-retardant components, a polyester long-fiber nonwoven fabric obtained by the spunbond method (manufactured by Toyobo Co., Ltd., trade name Ecure, basis weight 30g / m²) is used. 2A long-fiber nonwoven fabric (0.2 mm thick) was prepared. A flame-retardant long-fiber nonwoven fabric was obtained by applying and drying a polyester resin flame-retardant binder resin (manufactured by Go-o Chemical Industry Co., Ltd., product name Pluscoat Z-900, 25% emulsion) containing phosphorus in its polymer backbone to this long-fiber nonwoven fabric as the base material, thereby forming a coating of flame-retardant binder resin on the surface of the fibers constituting the base material. The amount of polyester resin flame-retardant binder resin applied was adjusted so that the dry mass after application was 10 parts by mass per 100 parts by mass of the base material.

[0216] (Example 5) A liquid absorbent was manufactured in the same manner as in Example 1, except that spunbond nonwoven fabrics manufactured as described below were used as the first and second base materials.

[0217] Specifically, first, polyethylene terephthalate with an intrinsic viscosity of 0.73 mPa·s was synthesized by condensation polymerization of bis(β-hydroxyethyl terephthalate).

[0218] Next, 10 parts by mass of 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide was added to 90 parts by mass of polyethylene terephthalate, stirred in a mixer, and then kneaded in a twin-screw extruder to obtain pellets of flame retardant-containing polyethylene terephthalate. The maximum barrel temperature during kneading was 270°C.

[0219] Next, the pellets were heated and melted at 270°C in an extrusion melt spinning machine, extruded and spun through the micropores, and the resulting continuous long fiber filaments were taken in by an ejector while being stretched with high-speed, high-pressure air, opened, and collected and deposited on the surface of a moving collection support to form a web. The obtained web was introduced between a bumpy roll and a smooth roll heated to 150°C, and the portions corresponding to the bumps of the bumpy roll were fused together to form a web with a basis weight of 30 g / m². 2A spunbond nonwoven fabric was obtained. The average particle size of 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide contained in the spunbond nonwoven fabric was 10 μm.

[0220] (Example 6) A liquid absorbent was manufactured in the same manner as in Example 2, except that ammonium polyphosphate with an average particle size of 10 μm was used as the flame retardant instead of aluminum hydroxide.

[0221] (Example 7) A liquid absorbent was manufactured in the same manner as in Example 2, except that melamine polyphosphate with an average particle size of 4 μm was used as the flame retardant instead of aluminum hydroxide.

[0222] (Example 8) A liquid absorbent was manufactured in the same manner as in Example 2, except that the ratio of cellulose fibers, heat-fusible resin, and flame retardant in the absorbent layer was set to 82:15:3 by mass.

[0223] (Example 9) Both the first and second base materials have a basis weight of 50 g / m². 2 A liquid absorbent was manufactured in the same manner as in Example 1, except that a phosphophenancelene ring-containing polyester long fiber nonwoven fabric obtained by the spunbond method was used.

[0224] (Example 10) Both the first and second base materials have a basis weight of 15 g / m². 2 A liquid absorbent was manufactured in the same manner as in Example 1, except that a phosphophenancelene ring-containing polyester long fiber nonwoven fabric obtained by the spunbond method was used.

[0225] (Example 11) A liquid absorbent was manufactured in the same manner as in Example 2, except that melamine cyanurate with an average particle size of 9 μm was used as the flame retardant instead of aluminum hydroxide.

[0226] (Comparative Example 1) Both the first and second base materials are non-flame retardant polyester filament nonwoven fabrics obtained by the spunbond method (manufactured by Toyobo Co., Ltd., trade name Ecure, basis weight 30g / m²). 2 A liquid absorbent was manufactured in the same manner as in Example 1, except that a material with a thickness of 0.2 mm was used.

[0227] (Comparative Example 2) A liquid absorbent was manufactured in the same manner as in Comparative Example 1, except that an apparatus equipped with a heat-fusible resin and flame retardant supply means was used instead of a heat-fusible resin supply means, and a mixture of the heat-fusible resin and flame retardant was supplied from the heat-fusible resin and flame retardant supply means. Ammonium polyphosphate with an average particle size of 10 μm was used as the flame retardant.

[0228] (Comparative Example 3) A liquid absorbent was manufactured in the same manner as in Example 1, except that an apparatus equipped with a heat-fusible resin and flame retardant supply means was used instead of a heat-fusible resin supply means, and a mixture of the heat-fusible resin and flame retardant was supplied from the heat-fusible resin and flame retardant supply means. As the flame retardant, aluminum hydroxide with an average particle size of 8 μm was used. Table 1 summarizes the configuration of the liquid absorbers in each of the above embodiments and comparative examples.

[0229] [Table 1]

[0230] [5] Rating The liquid absorbent obtained in the manner described above was evaluated as follows. [5-1] Ink penetration First, a mixed pigment ink for evaluation was prepared as follows.

[0231] Specifically, a black ink consisting of self-dispersing carbon black (Orient Chemical CW-1): 5% by mass (volume average particle size 150 nm), resin emulsion (styrene-acrylic acid): 3% by mass, acetylene-based surfactant (Orphine E1010): 0.5% by mass, glycerin: 5% by mass, 2-pyrrolidone: 2% by mass, 1,2-hexanediol: 2% by mass, and residual water; a colorant made by coating pigment yellow 74 with resin: 3% by mass; a yellow ink consisting of resin emulsion (styrene-acrylic acid): 3% by mass, acetylene-based surfactant (Orphine E1010): 0.3% by mass, glycerin: 3% by mass, 2-pyrrolidone: 2% by mass, 1,2-hexanediol: 2% by mass, and residual water; and a colorant made by coating pigment red 122 with resin. A magenta ink was prepared consisting of 3% by mass of pigment material, 3% by mass of resin emulsion (styrene-acrylic acid), 0.3% by mass of acetylene-based surfactant (Orphine E1010), 3% by mass of glycerin, 2% by mass of 2-pyrrolidone, 2% by mass of 1,2-hexanediol, and the remainder being water. A cyan ink was prepared consisting of 3% by mass of pigment material coated with resin in a 15:3 ratio of pigment blue, 3% by mass of resin emulsion (styrene-acrylic acid), 0.3% by mass of acetylene-based surfactant (Orphine E1010), 3% by mass of glycerin, 2% by mass of 2-pyrrolidone, 2% by mass of 1,2-hexanediol, and the remainder being water. These were mixed in equal masses, sealed in a container, and left to stand at 25°C for 14 days to be used as the mixed pigment ink for evaluation.

[0232] Furthermore, the resins used to coat Pigment Yellow 74, Pigment Red 122, and Pigment Blue 15:3 were water-insoluble polymers synthesized as follows: Methyl ethyl ketone as an organic solvent: 20 parts by mass, 2-mercaptoethanol as a polymerization chain transfer agent: 0.03 parts by mass, 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization initiator: 1.2 parts by mass, methacrylic acid: 20 parts by mass, styrene monomer: 45 parts by mass, polyethylene glycol monomethacrylate (PO=9): 5 parts by mass, polyethylene glycol-propylene glycol monomethacrylate (EO=5, PO=7): 10 parts by mass, and styrene macromer (Toa Go 20 parts by mass of (product name: AS-6S, number average molecular weight: 6000, polymerizable functional group: methacroyloxy group), manufactured by Seisha, was placed in a reaction vessel, and after thoroughly purging the inside of the reaction vessel with nitrogen gas, polymerization was carried out at 75°C under stirring. Subsequently, 0.9 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) dissolved in 40 parts by mass of methyl ethyl ketone was added to 100 parts by mass of the polymerizable component, and the mixture was aged at 80°C for 1 hour to obtain a water-insoluble polymer solution, which was then dried under reduced pressure to obtain a water-insoluble polymer. However, in the above description, PO represents propylene oxide and EO represents ethylene oxide.

[0233] Furthermore, the coating of the base pigment particles, namely pigment yellow 74, pigment red 122, and pigment blue 15:3, with the water-insoluble polymer was carried out as follows: 5 parts by mass of the water-insoluble polymer was dissolved in 15 parts by mass of methyl ethyl ketone, the polymer was neutralized with an aqueous sodium hydroxide solution, and then 15 parts by mass of the base pigment was added. The mixture was then kneaded in a disperser while adding water. After that, 100 parts by mass of ion-exchanged water was added to the resulting mixture and stirred. The methyl ethyl ketone was then removed under reduced pressure at 60°C, and some of the water was removed to obtain an aqueous dispersion of the colorant coated with the water-insoluble polymer (solid content concentration: 20% by mass).

[0234] Furthermore, the resin emulsion (styrene-acrylic acid) was obtained as follows: In a reaction vessel equipped with a stirrer, reflux condenser, dropping device, and thermometer, 800 g of deionized water and 1 g of sodium lauryl sulfate were charged, and the temperature was raised to 75°C while stirring and purging with nitrogen. Maintaining the internal temperature at 75°C, 6 g of potassium persulfate was added as a polymerization initiator. After dissolution, an emulsion prepared by adding 450 g of deionized water, 2 g of sodium lauryl sulfate, 20 g of acrylamide, 600 g of methyl methacrylate, 215 g of butyl acrylate, 30 g of methacrylic acid, and 5 g of triethylene glycol diacrylate to 450 g of deionized water and 2 g of sodium lauryl sulfate under stirring was continuously added dropwise to the reaction solution over 5 hours. After the addition was complete, the mixture was allowed to mature for 3 hours. After cooling the obtained aqueous emulsion to room temperature, deionized water and aqueous sodium hydroxide solution were added to adjust the solid content to 30% by mass and the pH to 8, thereby obtaining the resin emulsion (styrene-acrylic acid).

[0235] Using the mixed pigment ink obtained as described above, the permeability of the liquid absorbers produced in each of the above examples and comparative examples was evaluated as follows.

[0236] First, the liquid absorbent bodies produced in each of the above examples and comparative examples were placed with their 200 mm sides oriented vertically, with their lower ends in a container filled with mixed pigment ink, and left to stand. At this time, the liquid level of the mixed pigment ink in the container was positioned 15 mm from the lower end of the liquid absorbent body.

[0237] After standing for two hours, the height to which the pigment ink penetrated from the bottom edge of the liquid absorbent was measured and evaluated according to the following criteria. A greater penetration height indicates superior ink permeability.

[0238] A: Penetration height of 120mm or more. B: Penetration height is 100mm or more but less than 120mm. C: Penetration height is less than 100 mm.

[0239] [5-2] Flame retardant The burning rate of the liquid absorbent produced in each of the above examples and comparative examples was determined according to the method in accordance with JIS K6400-6. Specifically, for the liquid absorbent produced in each of the above examples and comparative examples, one end was held so that the 15 cm side was horizontal, and the other end was indirectly flamed with a 38 mm flame for 60 seconds. The burning rate at a distance of 100 mm between the markings was determined and evaluated according to the following criteria. A lower burning rate indicates superior flame retardancy.

[0240] A: The combustion rate is less than 5 mm / min. B: The combustion rate is 5 mm / min or more.

[0241] [5-3] Ink coagulation The ink coagulation properties of the liquid absorbents produced in each of the above examples and comparative examples were evaluated as follows. Specifically, 10 g of mixed pigment ink was placed in a sealed container with a lid, 1 g of liquid absorbent was immersed in it, the container was sealed tightly, and heated at 60°C for 72 hours. After that, the container was opened and visually observed, and the occurrence of ink coagulation in the liquid absorbent was evaluated according to the following criteria.

[0242] A: No aggregation is observed. B: Aggregation is observed on the surface of the liquid absorbent. C: The entire ink has gelled. These results are shown in Table 2.

[0243] [Table 2]

[0244] As is clear from Table 2, the present invention provides a liquid absorbent with excellent ink permeability and flame retardancy. Furthermore, it was confirmed that ink aggregation is effectively prevented in the present invention. From these results, it can be said that the liquid absorption performance can be stably and effectively maintained over a long period of time. In contrast, satisfactory results were not obtained in the comparative examples. [Explanation of Symbols]

[0245] A100...Liquid absorbent, A1...First base material, A2...Second base material, A3...Absorbent layer, P100...Sheet manufacturing apparatus, P1...Fiber supply means, P2...Fibre dissolution means, P3...Heat-fusible resin supply means, P4...Molding means, P41...Mixing unit, P42...Molding unit, P43...Immobilization unit, P5...Cutting means, P6...Conveying means, 1...Inkjet printer, 2...Printer case, 3...Power switch, 5...Roll paper cover, 6...Roll paper, 7...Ink cartridge cover, 8...Paper storage unit, 9...Cartridge mounting unit, 10...Ink cartridge, 11,12,13...Ink pack, 15...C Cartridge case, 17...waste ink storage structure, 21...bag body, 23...ink outlet, 23a...cylindrical body, 23b...valve body, 23c...seal film, 31...upper case, 31a...front container wall, 31b...ink pack positioning part, 31c...side wall, 31d...locking projection, 31e...top wall, 33...lower case, 33a...engaging part, 33b...front container wall, 33c...ink pack positioning part, 33d...cover part, 33e...opening, 33f...side container wall, 33g, 33h...front and rear container walls, 33i...bottom wall, 35...intermediate container wall, 37...waste ink introduction part, 37a...rubber mouth member, 37b... Seal film, 37c…valve body, 37d…compression coil spring, 41…ink supply needle, 42…supply tube, 44…inlet, 47…waste ink introduction needle, 49…waste ink guide tube, 51…storage space, 53…IC module, 55…storage space, 61…vent hole, 63…ink absorbent material, 63a…hole, 65…on / off valve, 67…structural member for valve, 67a…positioning projection, 67b…stepped surface, 101…inkjet printer, 111…printer housing, 111s…tank housing, 112…outer cover, 115…printer mechanism, 116…power unit, 120… Waste ink tank, 121...tank body, 122, 122A, 122B, 122C, 122D...ink absorbent material, 1221...central hole, 1222...tube housing groove, 123...sealing material, 124...lid, 125...tube, 125a...base inlet, 125b...tip outlet, 127...ink receptacle, 151...storage space, 171...on-off valve, 173...vent hole, 174...valve body, 174a...flange, 174b...cylindrical part, 174c...on-off part, 174d...notch, 175...on-off valve, 177...valve seat, 177a...stepped surface, 178...valve body, 178a...valve body, 178b...support part, S...seat

Claims

1. A first base material and a second base material that primarily exhibit flame retardancy, The device comprises an absorbent layer provided between the first substrate and the second substrate, which mainly absorbs and retains liquids, Both the first and second substrates contain a flame-retardant long-fiber nonwoven fabric. The flame retardant content in the absorbent layer is less than 4% by mass. The absorbent layer is a liquid absorbent containing hydroxide as the flame retardant.

2. The liquid absorbent according to claim 1, wherein the long-fiber nonwoven fabric is a spunbond nonwoven fabric.

3. The liquid absorbent according to claim 1 or 2, wherein the flame-retardant long-fiber nonwoven fabric includes fibers composed of a polymer containing flame-retardant monomer components.

4. The liquid absorbent according to claim 3, wherein the flame-retardant monomer component is a phosphorus-containing compound.

5. The liquid absorbent according to any one of claims 1 to 4, wherein the flame-retardant long-fiber nonwoven fabric is coated with a flame retardant on the surface of the long-fiber nonwoven fabric.

6. The liquid absorbent according to any one of claims 1 to 5, wherein the flame-retardant long-fiber nonwoven fabric is formed by molding a mixture containing a resin material and a flame retardant.

7. The liquid absorbent according to any one of claims 1 to 6, wherein the absorbent layer comprises cellulose fibers and a heat-sealable resin.

8. The liquid absorbent according to any one of claims 1 to 7, wherein the liquid absorbent is used for absorbing ink.

9. The liquid absorbent according to any one of claims 1 to 8, wherein the liquid absorbent is used for absorbing pigment ink containing a pigment.

10. A printing apparatus comprising a liquid absorbent according to any one of claims 1 to 9.

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