Liquid absorber and liquid absorber

Abstract

The invention provides a liquid absorber and a liquid absorber which can rapidly diffuse supplied liquid and have excellent absorption characteristics. The liquid absorbent is characterized by being provided with: an absorbent layer having a water-absorbent resin and having liquid absorbency; and a liquid-permeable base layer that is laminated on at least one surface side of the absorbent layer, the base layer having a first layer that contains cellulose and a second layer that is located on the opposite side of the first layer from the absorbent layer and that has a basis weight different from that of the first layer, when the basis weight of the first layer is A1 (g / cm2) and the basis weight of the second layer is A2 (g / cm2), A2 < A1 is satisfied.

Description

Technical Field

[0001] The invention relates to a liquid absorber and a liquid absorber. Background Art

[0002] For example, in an inkjet printer, waste ink is generated during a head cleaning operation performed to prevent a decrease in printing quality due to clogging of ink, and during an ink filling operation after replacing an ink cartridge. In addition, there is also a possibility that ink may leak from a place not intended by the inkjet printer. An ink absorber that absorbs such ink is known. For example, Patent Document 1 discloses an ink absorber that is contained in a container and is composed of felt or the like containing fibers.

[0003] However, the ink absorption characteristics, especially the ink diffusibility, of the ink absorber described in Patent Document 1 are not sufficient. Therefore, depending on the ink dropping conditions, the diffusion speed of the ink dripped onto the ink absorber is slow and the ink is not diffused over the entire body. As a result, the absorption capacity of the ink absorber decreases.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-65112 Summary of the invention

[0005] The liquid absorbent of the present invention comprises:

[0006] an absorbent layer having a water-absorbent resin and having liquid absorbency;

[0007] a base layer which is laminated on at least one surface side of the absorbent layer and has liquid permeability,

[0008] The base layer comprises a first layer and a second layer, the first layer comprises cellulose, the second layer is located on a side of the first layer opposite to the absorbent layer, and the gram weight of the second layer is different from the gram weight of the first layer.

[0009] When the gram weight of the first layer is set to A1 and the gram weight of the second layer is set to A2, A2<A1 is satisfied, wherein the units of A1 and A2 are g / cm 2 .

[0010] The liquid absorber of the present invention comprises:

[0011] The liquid absorbent of the present invention;

[0012] The container accommodates the liquid absorber and has a liquid supply portion to which the liquid is supplied. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a side cross-sectional view of a liquid absorber and a liquid absorber according to an embodiment of the present invention.

[0014] Figure 2 for Figure 1 An enlarged cross-sectional view of the liquid absorber is shown.

[0015] Figure 3 for Figure 1 A top view of the liquid absorber is shown.

[0016] Figure 4 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown.

[0017] Figure 5 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown.

[0018] Figure 6 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown.

[0019] Figure 7 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown. DETAILED DESCRIPTION

[0020] Hereinafter, the liquid absorber and the liquid absorber of the present invention will be described in detail based on the preferred embodiments shown in the drawings.

[0021] First embodiment

[0022] Figure 1 It is a side cross-sectional view of a liquid absorber and a liquid absorber according to an embodiment of the present invention. Figure 2 for Figure 1 An enlarged cross-sectional view of the liquid absorber is shown. Figure 3 for Figure 1 A top view of the liquid absorber is shown. Figure 4 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown. Figure 5 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown. Figure 6 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown. Figure 7 For use in Figure 1 A side cross-sectional view illustrating a method for manufacturing a liquid absorbent body is shown.

[0023] In addition, in the following, for the sake of convenience, Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 as well as Figure 7 The upper side in the description is referred to as “upper” or “above”, and the lower side is referred to as “lower” or “below”.

[0024] like Figure 1 As shown, the liquid absorber 10 includes a liquid absorber 1 and a container 6 for storing the liquid absorber 1. The container 6 has an opening 60 that opens upward. In the present embodiment, the container 6 is a tray. The container 6 is made of a hard material such as resin, glass, ceramic, or metal material, and has liquid impermeability. The opening 60 functions as a liquid supply unit that supplies a liquid such as ink 100 to the liquid absorber 1. The liquid supplied through the opening 60 is absorbed and retained by the liquid absorber 1. Such a liquid absorber 10 is, for example, provided in a printing device, and is used as a liquid absorber for recovering waste ink, i.e., discarded ink 100. The liquid absorber 10 can also be used to recover waste liquid other than waste ink.

[0025] Examples of the liquid absorbed by the liquid absorber 1 include water, ink, and body fluids. Ink includes, of course, water-based inks in which a color material is dissolved in a water-based solvent, solvent-based inks in which a binder is dissolved in a solvent, UV-curable inks in which a binder is dissolved in a liquid monomer that is cured by UV irradiation, and latex inks in which a binder is dispersed in a dispersion medium. Ink 100 is cited as a representative example of the liquid absorbed by the liquid absorber 1 for explanation.

[0026] like Figure 1 As shown, the liquid absorber 1 has an absorbent layer 3 and a base layer 2, wherein the absorbent layer 3 has liquid absorbency, and the base layer 2 is stacked on both sides of the absorbent layer 3 and has liquid permeability. The ink 100 supplied to the upper base layer 2 through the opening 60 penetrates into the base layer 2, diffuses in the surface direction and thickness direction of the base layer 2, and then transfers to the absorbent layer 3 adjacent to the inner side of the base layer 2, and is absorbed and retained by the absorbent layer 3. The liquid absorber 1 is in the form of a thin sheet as a whole. However, it is not limited to this structure, and the liquid absorber 1 may also be in other shapes such as a block.

[0027] Although the sheet-like liquid absorber 1 is in a flat plate shape in the structure of the drawings, it may be entirely or partially bent or curved unlike the figure.

[0028] Hereinafter, the structures of the absorption layer 3 and the base layer 2 will be described.

[0029] Absorption layer 3

[0030] The absorption layer 3 is mainly composed of a water-absorbent resin 30. The water-absorbent resin 30 is a resin that has water absorption and swells with water absorption. Although the water-absorbent resin 30 is not particularly limited, examples thereof include carboxymethyl cellulose, polyacrylic acid, polyacrylamide, starch-acrylic acid graft copolymer, hydrolyzate of starch-acrylonitrile graft copolymer, vinyl acetate-acrylate copolymer, copolymer of isobutylene and maleic acid, hydrolyzate of acrylonitrile copolymer or acrylamide copolymer, polyethylene oxide, polysulfonic acid compounds, polyglutamic acid, or their salts (neutralized products), crosslinked products, etc. Here, water absorption refers to the function of having hydrophilicity and retaining water. Among the water-absorbent resin 30, there are many substances that gel when absorbing water.

[0031] Among them, the water-absorbent resin 30 is preferably a resin having a functional group on a side chain. Examples of the functional group include an acid group, a hydroxyl group, an epoxy group, and an amino group.

[0032] In particular, the water-absorbent resin 30 is preferably a resin having an acid group on a side chain, and more preferably a resin having a carboxyl group on a side chain.

[0033] Examples of the carboxyl group-containing unit constituting the side chain include those derived from monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, fumaric acid, sorbic acid, cinnamic acid, or anhydrides and salts thereof.

[0034] In the case of the water-absorbent resin 30 having an acid group on the side chain, the proportion of the substance that is neutralized to form a salt among the acid groups contained in the water-absorbent resin 30 is preferably 30 mol% or more and 100 mol% or less, more preferably 50 mol% or more and 95 mol% or less, and further preferably 60 mol% or more and 90 mol% or less. Thus, the absorbency of the ink 100 by the water-absorbent resin 30 can be made even better.

[0035] The type of salt for neutralization is not particularly limited, and examples thereof include alkali metal salts such as sodium salts, potassium salts, and lithium salts, and salts of nitrogen-containing alkaline substances such as ammonia, among which sodium salts are preferred. Thus, the absorbency of the ink 100 by the water-absorbing resin 30 can be further improved.

[0036] The water-absorbent resin 30 having an acid group on the side chain is preferred because it causes electrostatic repulsion between the acid groups when the ink is absorbed, thereby increasing the absorption speed. In addition, when the acid group is neutralized, the ink 100 is easily absorbed into the water-absorbent resin 30 due to osmotic pressure.

[0037] The water-absorbing resin 30 may have a structural unit having no acid group in the side chain. Examples of such a structural unit include a hydrophilic structural unit, a hydrophobic structural unit, and a structural unit that serves as a polymerizable crosslinking agent.

[0038] Examples of the hydrophilic structural unit include structural units derived from nonionic compounds such as acrylamide, methacrylamide, N-ethyl(meth)acrylamide, N-n-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, methoxypolyethylene glycol(meth)acrylate, polyethylene glycol mono(meth)acrylate, N-vinylpyrrolidone, N-acryloylpiperidine, and N-acryloylpyrrolidine.

[0039] Examples of the hydrophobic structural unit include structural units derived from compounds such as (meth)acrylonitrile, styrene, vinyl chloride, butadiene, isobutylene, ethylene, propylene, stearyl (meth)acrylate, and lauryl (meth)acrylate.

[0040] Examples of the constituent unit that serves as the polymerizable crosslinking agent include constituent units derived from diethylene glycol diacrylate, N,N'-methylenebisacrylamide, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane diallyl ether, trimethylolpropane triacrylate, allyl glycidyl ether, pentaerythritol triallyl ether, pentaerythritol diacrylate monostearate, bisphenol diacrylate, isocyanuric acid diacrylate, tetraallyloxyethane, diallyloxyacetate, and the like.

[0041] The water-absorbent resin 30 preferably contains a polyacrylic acid salt copolymer or a cross-linked polyacrylic acid polymer, which has advantages such as improved absorption performance for liquids and reduced manufacturing costs.

[0042] In the cross-linked polyacrylic acid polymer, the proportion of the structural unit having a carboxyl group in all structural units constituting the molecular chain is preferably 50 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more.

[0043] If the ratio of the structural unit containing a carboxyl group is too small, it may be disadvantageous to make the absorption performance of the ink 100 sufficiently excellent.

[0044] It is preferred that a part of the carboxyl groups in the cross-linked polyacrylic acid polymer is neutralized (partially neutralized) to form a salt.

[0045] The ratio of neutralized carboxyl groups in the cross-linked polyacrylic acid polymer to all carboxyl groups is preferably 30 mol% to 99 mol%, more preferably 50 mol% to 99 mol%, and even more preferably 70 mol% to 99 mol%.

[0046] Furthermore, the water-absorbing resin 30 may have a structure cross-linked by a cross-linking agent other than the polymerizable cross-linking agent described above.

[0047] When the water-absorbent resin 30 is a resin having an acid group, as the cross-linking agent, for example, a compound having a plurality of functional groups reactive with the acid group can be preferably used.

[0048] When the water-absorbent resin 30 is a resin having a functional group reactive with an acid group, a compound having a plurality of functional groups reactive with an acid group in the molecule can be preferably used as the cross-linking agent.

[0049] Examples of compounds (crosslinking agents) having multiple functional groups that react with acid groups include glycidyl ether compounds such as ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, (poly)glycerol polyglycidyl ether, diglycerol polyglycidyl ether, and propylene glycol diglycidyl ether; polyols such as (poly)glycerol, (poly)ethylene glycol, propylene glycol, 1,3-propylene glycol, polyoxyethylene glycol, triethylene glycol, tetraethylene glycol, diethanolamine, and triethanolamine; polyamines such as ethylenediamine, diethylenediamine, polyethyleneimine, and hexamethylenediamine, etc. In addition, polyvalent ions such as zinc, calcium, magnesium, and aluminum can also react with the acid groups of the water-absorbent resin 30 to function as crosslinking agents, and therefore can be preferably used.

[0050] The water-absorbent resin 30 may be in any shape, such as scale, needle, fiber, or particle, but preferably most of them are in particle form. When the water-absorbent resin 30 is in particle form, it is easy to ensure the permeability of the ink 100. The average particle size of the particles is preferably 10 μm or more and 1000 μm or less, more preferably 50 μm or more and 800 μm or less, and further preferably 100 μm or more and 600 μm or less.

[0051] In addition, the absorption layer 3 may contain components (other components) other than the water-absorbent resin 30. Examples of such components include surfactants, lubricants, defoamers, fillers, ion exchange resins, activated carbon, zeolites, anti-blocking agents, ultraviolet absorbers, colorants such as pigments and dyes, flame retardants, and fluidity improvers.

[0052] Such a water-absorbent resin 30 may be supported on the base layer 2, in particular, the first layer 21 described later, or may not be supported. When the water-absorbent resin 30 is supported on the base layer 2, the position of the water-absorbent resin 30 can be restricted to a certain extent, thereby preventing the water-absorbent resin 30 from having uneven portions in the absorption layer 3. Therefore, the liquid absorber 1 can uniformly exhibit excellent absorption characteristics.

[0053] The method of supporting the water-absorbent resin 30 on the base layer 2 is not particularly limited, and examples thereof include a method of bonding the water-absorbent resin 30 to the base layer 2 using a binder, or a method of bonding the water-absorbent resin 30 by giving moisture to the water-absorbent resin 30 so that it exhibits adhesiveness and the like. When a binder is used, the binder used is not particularly limited, but a water-soluble binder is preferably used. Thus, when the ink 100 is aqueous, the water-soluble binder dissolves when the ink 100 comes into contact with the binder, thereby preventing the ink 100 from being blocked from penetrating into the water-absorbent resin 30.

[0054] When the volume of the water-absorbent resin 30 before drying and absorbing the ink 100 is V1 and the volume after absorbing the ink 100 to the maximum extent is V2, V2 / V1 is preferably 2 to 1000, more preferably 5 to 250. Thus, a sufficient amount of ink 100 can be absorbed.

[0055] Base layer 2

[0056] like Figure 2 As shown, the base layer 2 is stacked on the upper surface 31 side and the lower surface 32 side, respectively, wherein the upper surface 31 side is one surface side of the absorbent layer 3, and the lower surface 32 side is the other surface side of the absorbent layer 3. That is, the liquid absorbent body 1 has a structure in which the absorbent layer 3 is inserted between two base layers 2. In this embodiment, since the structures of the two base layers 2 are the same, the base layer 2 on the upper surface 31 side will be representatively described below.

[0057] The base layer 2 includes a first layer 21 and a second layer 22. In this embodiment, the shapes of the first layer 21 and the second layer 22 when viewed from above, i.e. Figure 3 The shape shown is roughly square, but it is not limited to this structure, and it can also be any shape such as a rectangle, a triangle, a circle, an ellipse, a semicircle, a fan, a ring, a polygon with more than pentagons, etc.

[0058] The first layer 21 and the second layer 22 may be bonded to each other at their boundary, in contact with each other, or separated at a predetermined interval. In the present embodiment, the first layer 21 and the second layer 22 are bonded to each other with a slight bonding force.

[0059] like Figure 2 As shown, the first layer 21 is located on the side of the absorbent layer 3 and faces the absorbent layer 3. The first layer 21 and the absorbent layer 3 may be bonded to each other at their boundary, in contact with each other, or separated at a predetermined interval. In this embodiment, the first layer 21 is in contact with the absorbent layer 3.

[0060] The first layer 21 is a paper substrate mainly composed of cellulose fibers.

[0061] Since cellulose is a material having appropriate hydrophilicity, when the ink 100 is applied to the first layer 21, the ink 100 can be efficiently introduced, and the ink 100 can be quickly removed from a state with particularly high fluidity, for example, a state with a viscosity of 10 mPa·s or less. Furthermore, the ink 100 introduced once can be efficiently sent to the water-absorbent resin 30. As a result, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be made particularly excellent. In addition, since cellulose fiber is a renewable natural material and is easily available at a low price among various fibers, it is also advantageous from the viewpoints of reducing the production cost of the liquid absorber 1, stabilizing production, reducing environmental load, etc.

[0062] In the present specification, the cellulose fiber may be any fiber having cellulose as a compound as a main component and in a fibrous form, and may be a fiber containing hemicellulose or lignin in addition to cellulose.

[0063] Although the average length of the cellulose fibers constituting the first layer 21 is not particularly limited, it is preferably 0.1 mm to 7 mm, more preferably 0.13 mm to 5 mm, and even more preferably 0.15 mm to 3 mm.

[0064] Although the average width (diameter) of the cellulose fibers constituting the first layer 21 is not particularly limited, it is preferably 0.05 mm to 2 mm, and more preferably 0.1 mm to 1 mm.

[0065] The average aspect ratio of the cellulose fibers constituting the first layer 21 , that is, the ratio of the average length to the average width, is not particularly limited, but is preferably 10 to 1000, and more preferably 15 to 500.

[0066] By setting the above numerical range, it is possible to obtain appropriate diffusibility of the ink 100 on the first layer 21. In addition, the first layer 21 has excellent loading capacity for the water-absorbent resin 30, so that the ink 100 can be efficiently transferred to the water-absorbent resin 30. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be made more excellent.

[0067] like Figure 2 As shown, the second layer 22 is located on the side of the first layer 21 opposite to the absorption layer 3. That is, the second layer 22 is located on the surface of the liquid absorber 1. The second layer 22 is a portion to which the ink 100 is supplied, and has a function of rapidly permeating and diffusing the ink 100 after it is introduced, and has a function of diffusing in the surface direction of the second layer 22 in particular.

[0068] The second layer 22 includes fibers. Examples of the fibers of the second layer 22 include synthetic resin fibers such as polyester fibers and polyamide fibers, natural resin fibers such as cellulose fibers, keratin fibers, and silk protein fibers, or chemically modified products thereof, and these fibers can be used alone or in appropriate combinations. In this embodiment, the second layer 22 is a nonwoven fabric formed of the fibers.

[0069] Although the average length of the fibers constituting the second layer 22 is not particularly limited, it is preferably 0.05 mm to 6 mm, more preferably 0.06 mm to 4 mm, and further preferably 1.00 mm to 2 mm.

[0070] Although the average width (diameter) of the fibers constituting the second layer 22 is not particularly limited, it is preferably 0.04 mm to 1.8 mm, and more preferably 0.08 mm to 0.9 mm.

[0071] The average aspect ratio (ratio of average length to average width) of the fibers constituting the second layer 22 is not particularly limited, but is preferably 10 or more and 1000 or less, and more preferably 15 or more and 500 or less.

[0072] By setting the value in the above range, good diffusibility of the ink 100 on the second layer 22 can be obtained. In addition, the second layer 22 can efficiently transfer the ink 100 to the water-absorbing resin 30. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be made more excellent.

[0073] Furthermore, the second layer 22 is a nonwoven fabric. This can improve the diffusibility of the ink 100 in the surface direction of the second layer 22, and eliminate the unevenness of the diffusibility in the diffusing direction.

[0074] However, the second layer 22 is not limited to nonwoven fabric, and may be composed of, for example, woven fabric or the same paper base material as the first layer 21. The second layer 22 may be a combination of woven fabric, nonwoven fabric, and paper base material as appropriate.

[0075] The second layer 22 is preferably hydrophilic. This further improves the diffusibility of the ink 100. The second layer 22 is hydrophilic when the fibers constituting the second layer 22 are hydrophilic, when the fibers constituting the second layer 22 are hydrophilic, or when the surface of the second layer 22 is hydrophilic.

[0076] Examples of the hydrophilization treatment include chemical treatment such as adding a surfactant or physical treatment such as a plasma treatment.

[0077] The first layer 21 and the second layer 22 may be made of the same material or different materials. In particular, the fibers included in the first layer 21 and the fibers included in the second layer 22 may be made of the same material, partially the same material, or completely different materials.

[0078] Furthermore, in addition to the above-mentioned fibers, a binder for bonding the fibers together may be included in the first layer 21 and the second layer 22. Thus, the strength of the first layer 21 and the second layer 22 can be sufficiently improved, and unintended partial breakage can be prevented.

[0079] The binder is not particularly limited and includes, for example, thermoplastic resins, thermosetting resins, starch, dextrin, glycogen, amylose, hyaluronic acid, kudzu, konjac, pig tooth pollen, etherified starch, esterified starch, natural gum paste (etherified tamarind gum, etherified locust bean gum, etherified guar gum, gum arabic), fiber-sensing paste (etherified carboxymethyl cellulose, hydroxyethyl cellulose), seaweed (sodium alginate, agar), animal protein (collagen, gelatin, hydrolyzed collagen, sericin), etc., but preferably, a thermoplastic resin is used.

[0080] Examples of the thermoplastic resin include polyolefins such as AS resin, ABS resin, polyethylene, polypropylene, and ethylene-vinyl acetate copolymer (EVA), acrylic resins such as modified polyolefins and polymethyl methacrylate, polyesters such as polyvinyl chloride, polystyrene, polyethylene terephthalate, and polybutylene terephthalate, polyamides such as nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, and nylon 6-66. Liquid crystal polymers such as polyphenylene ether, polyacetal, polyether, polyphenylene ether, polyether ether ketone, polycarbonate, polyphenylene sulfide, thermoplastic polyimide, polyetherimide, aromatic polyester, various thermoplastic elastomers such as styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans-polyisoprene, fluororubber, chlorinated polyethylene, etc., and one selected from these substances or a combination of two or more selected substances can be used. Preferably, polyester or a substance containing polyester is used as the thermoplastic resin.

[0081] In addition to the above-mentioned adhesives, for example, colorants for coloring fibers, aggregation inhibitors for inhibiting aggregation of fibers or adhesives, flame retardants for making fibers less flammable, and paper strength enhancers for enhancing paper strength may also be included.

[0082] In such a base layer 2, the basis weight of the first layer 21, that is, the basis weight of the material constituting the first layer 21 is set to A1 (g / cm 2 ), and the gram weight of the second layer 22, that is, the gram weight of the material constituting the second layer 22 is set to A2 (g / cm 2 ), A2<A1.

[0083] According to this structure, Figure 2 As shown, the ink 100 applied to the second layer 22 quickly and sufficiently diffuses to a distant place in the surface direction of the second layer 22, and also diffuses in the thickness direction of the layer and transfers to the first layer 21. In addition, the ink 100 once transferred to the first layer 21 does not return to the second layer 22 side, but transfers to the absorption layer 3 in contact with the first layer 21, and is absorbed and retained by the absorption layer 3. Therefore, the ink 100 can be quickly absorbed and retained in a wider range of the liquid absorber 1, so that the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0084] In particular, since the ink 100 quickly and fully diffuses to a distant place along the surface direction on the second layer 22, the ink 100 can be absorbed and retained by the entire absorption layer 3 without omission. Therefore, the liquid absorber 1 does not experience the transfer and diffusion stagnation of the ink 100 inside, and can quickly absorb and retain more ink 100.

[0085] Although A1 is not particularly limited, it is preferably 0.02 g / cm 2 Above and 2.0g / cm 2 Below, more preferably 0.05 g / cm 2 Above and 1.5g / cm 2 the following.

[0086] Although A2 is not particularly limited, it is preferably 0.01 g / cm 2 Above and 1.8g / cm 2 Below, more preferably 0.04 g / cm 2 Above and 1.2g / cm 2 the following.

[0087] By setting A1 and A2 to the above numerical range, the above-described effect obtained by satisfying A2<A1 can be more significantly exhibited.

[0088] The ratio A1 / A2 of A1 to A2 is preferably 1.1 to 5, and more preferably 1.2 to 4. Thus, the above-described effect obtained by satisfying A2<A1 can be more reliably and significantly exerted.

[0089] In addition, it is preferable that the density of the first layer 21, that is, the density of the material constituting the first layer 21, is set to B1 (g / cm 3 ), and the density of the second layer 22, that is, the density of the material constituting the second layer 22 is set to B2 (g / cm 3 ), B2<B1.

[0090] Thus, the ink 100 applied to the second layer 22 quickly and sufficiently diffuses to a distant place in the surface direction of the second layer 22, and also diffuses in the thickness direction of the layer and transfers to the first layer 21. In addition, the ink 100 once transferred to the first layer 21 does not return to the second layer 22 side, but transfers to the absorption layer 3 in contact with the first layer 21, and is absorbed and retained by the absorption layer 3. Therefore, the ink 100 can be quickly absorbed and retained in a wider range of the liquid absorber 1, and the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0091] In addition, although B1 is not particularly limited, it is preferably 0.02 g / cm 3 Above and 0.8g / cm 3 Below, more preferably 0.06 g / cm 3 Above and 0.5g / cm 3 the following.

[0092] In addition, although B2 is not particularly limited, it is preferably 0.01 g / cm 3 Above and 0.5g / cm 3 Below, more preferably 0.05 g / cm 3 Above and 0.3g / cm 3 the following.

[0093] By setting B1 and B2 to the above numerical range, the above-described effect obtained by satisfying B2<B1 can be more significantly exhibited.

[0094] The ratio B1 / B2 of B1 to B2 is preferably 1.3 to 4, and more preferably 1.5 to 2. Thus, the above-described effect obtained by satisfying B2<B1 can be more reliably and significantly exerted.

[0095] In addition, the present invention is not limited to the above-mentioned structure, and B1=B2 may be satisfied, or B1<B2 may be satisfied.

[0096] In addition, it is preferable that when the thickness (average thickness) of the first layer 21 is set to T1 (mm) and the thickness (average thickness) of the second layer 22 is set to T2 (mm), T2<T1 is satisfied. Thus, the ink 100 applied to the second layer 22 is more effectively diffused along the surface direction of the second layer 22, and the ink 100 transferred to the first layer 21 can be more effectively prevented from being folded back to the second layer 22 side. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0097] Although T1 is not particularly limited, it is preferably, for example, 0.2 mm or more and 10 mm or less, and more preferably 0.6 mm or more and 5 mm or less.

[0098] Although T2 is not particularly limited, it is preferably, for example, 0.1 mm or more and 8 mm or less, and more preferably 0.5 mm or more and 4 mm or less.

[0099] By setting T1 and T2 to the above numerical range, the above-described effect obtained by satisfying T2<T1 can be more significantly exhibited.

[0100] Although the ratio T1 / T2 of T1 to T2 is not particularly limited, it is preferably 1.2 or more and 5 or less, and more preferably 1.5 or more and 3 or less. Thus, the effect of rapidly and sufficiently diffusing the ink 100 to a distant place in the surface direction on the second layer 22 and rapidly transferring the ink 100 to the first layer 21 can be more significantly exerted.

[0101] In addition, the present invention is not limited to the above-mentioned structure, and T1=T2 may be satisfied, or T1<T2 may be satisfied.

[0102] In addition, it is preferable that when the diffusion speed of the ink 100 in the surface direction of the first layer 21 is set to C1 (mm / s), and the diffusion speed of the ink 100 in the surface direction of the second layer 22 is set to C2 (mm / s), C1<C2 is satisfied. Thus, the ink 100 applied to the second layer 22 can be rapidly diffused to a further distance in the surface direction on the second layer 22. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0103] Although C1 is not particularly limited, it is preferably, for example, 0.5 mm / s to 8 mm / s, and more preferably 1 mm / s to 6 mm / s.

[0104] Although C2 is not particularly limited, it is preferably, for example, 1 mm / s to 10 mm / s, and more preferably 2 mm / s to 8 mm / s.

[0105] By setting C1 and C2 to the above numerical range, the above-described effect obtained by satisfying C1<C2 can be more significantly exhibited.

[0106] Although the ratio C2 / C1 of C1 to C2 is not particularly limited, it is preferably 1.2 to 4, and more preferably 1.5 to 2. Thus, the effect of rapidly and sufficiently diffusing the ink 100 to a distant place in the surface direction on the second layer 22 and rapidly transferring the ink 100 to the first layer 21 can be more significantly exerted.

[0107] In addition, A1, A2, B1, B2, T1, T2, C1, and C2 are values ​​obtained by excluding a sealing portion 4 described later.

[0108] As described above, the liquid absorbent 1 comprises: an absorbent layer 3 having a water-absorbent resin 30 and having liquid absorbency; a base layer 2 which is laminated on at least one side of the absorbent layer 3, and in this embodiment, on both sides, and has liquid permeability, the base layer 2 comprising a first layer 21 and a second layer 22, the first layer 21 comprising cellulose, the second layer 22 being located on the side of the first layer 21 opposite to the absorbent layer 3, and the gram weight of the second layer 22 being different from the gram weight of the first layer 21. In addition, when the gram weight of the first layer 21 is set to A1 (g / cm 2 ), and the grammage of the second layer 22 is set to A2 (g / cm 2), A2<A1 is satisfied. As a result, the liquid absorption property of the liquid absorber 1, for example, the absorption property of the ink 100 can be made excellent. Since the ink 100 is rapidly and fully diffused to a distant place along the surface direction on the base layer 2, especially the first layer 21 constituting the base layer 2, the ink 100 can be absorbed and retained by the entire absorption layer 3 without omission. As a result, the absorption capacity of the ink 100 of the liquid absorber 1 can be increased.

[0109] In addition, an intermediate layer may be formed between the first layer 21 and the second layer 22. Examples of the intermediate layer include a fixing layer that fixes the first layer 21 and the second layer 22 and a gap forming layer that forms a gap between the first layer 21 and the second layer 22.

[0110] In addition, the liquid absorber 10 includes a liquid absorber 1 and a container 6, wherein the container 6 accommodates the liquid absorber 1 and has a liquid supply portion, that is, an opening 60 to which the ink 100 as a liquid is supplied. Thus, the liquid absorber 1 having excellent absorption characteristics of the liquid, such as the ink 100, can be stably arranged at a desired position, such as in a printing device. Since such a liquid absorber 10 can absorb and hold a sufficient amount of liquid, it is advantageous for recovering waste liquid such as waste ink.

[0111] The structure of the liquid supply unit is appropriately determined according to the type and shape of the container 6 . For example, when the container 6 is a bottle, the mouth of the bottle serves as the liquid supply unit.

[0112] In addition, although the container 6 is composed of a hard tray or the like in the present embodiment, the present invention is not limited thereto, and for example, the container 6 may be a hard or soft bottle, a frame, or a soft bag.

[0113] In addition, when the density of the first layer 21 is set to B1 (g / cm 3 ), and the density of the second layer 22 is set to B2 (g / cm 3 ), B2<B1 is satisfied. Thus, the ink 100 can be rapidly diffused to a greater distance in the surface direction on the base layer 2. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0114] In addition, when the thickness of the first layer 21 is set to T1 (mm) and the thickness of the second layer 22 is set to T2 (mm), T1 / T2 is 1.2 or more and 5 or less. Thus, the ink 100 can be rapidly diffused to a further distance in the surface direction on the base layer 2. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0115] In addition, when the diffusion speed of the liquid in the surface direction of the first layer 21 is set to C1 (mm / s), and the diffusion speed of the liquid in the surface direction of the second layer 22 is set to C2 (mm / s), C1<C2 is satisfied. As a result, the ink 100 can be rapidly diffused to a farther distance in the surface direction on the base layer 2. Therefore, the absorption characteristics of the ink 100 as the entire liquid absorber 1 can be further improved.

[0116] In addition, the base layer 2 is laminated on the upper surface 31 side, which is one surface side of the absorption layer 3, and the lower surface 32 side, which is the other surface side of the absorption layer 3. Thus, the liquid, that is, the ink 100 can be absorbed from any surface side of the liquid absorber 1, and the versatility is excellent.

[0117] In other words, when the liquid absorber 1 is housed in the container 6, the liquid absorber 1 can be placed in the container 6 without having to worry about the front and back of the liquid absorber 1, thereby achieving excellent interchangeability, operability, and versatility.

[0118] The structure of the base layer 2 on the upper surface 31 side and the structure of the base layer 2 on the lower surface 32 side may be the same or different. In the latter case, when the constituent materials of the first layer 21 and the second layer 22 are different, at least one of A1, A2, B1, B2, T1, T2, C1, and C2 may be different.

[0119] In addition, in the present invention, a structure having the base layer 2 only on one side of the absorbent layer 3 is also possible. In this case, the other side of the absorbent layer 3 may be, for example, a base layer composed of a first layer and a second layer that do not satisfy A2<A1, a single layer or sheet having liquid permeability, a sheet having liquid impermeability, a plate, a wall portion, the bottom surface of the container 6, or any other structure having an open opening.

[0120] like Figure 1 as well as Figure 3 As shown, the liquid absorber 1 has a sealing portion 4 that seals the base layer 2 on the upper surface 31 side and the base layer 2 on the lower surface 32 side of the absorbent layer 3. The sealing portion 4 is also a portion that joins the edge portions of the first layer 21 and the second layer 22 of the two base layers 2 to each other. In this embodiment, the edge portions of the base layer 2 on the upper surface 31 side and the base layer 2 on the lower surface 32 side are joined and sealed by the sealing portion 4 over the entire circumference. Figure 3 As shown in FIG. 1 , the seal portion 4 is frame-shaped in a plan view. By providing such a seal portion 4, it is possible to suppress or prevent the water-absorbent resin 30 of the absorbing layer 3 or the absorbed ink 100 from unintentionally flowing out to the outside.

[0121] The seal portion 4 is not limited to being formed on the entire periphery of the edge of the two base layers 2, and a portion of the entire periphery of the edge may be missing. Thus, the liquid absorbent body 1 has a structure in which the base layers 2 are partially open.

[0122] The joining method of the sealing portion 4 is not particularly limited, and examples thereof include welding such as heat welding, ultrasonic welding, high-frequency welding, bonding using an adhesive, thermocompression bonding, double-sided tape fixing, suturing, pinning, stapler fixing, clamp fixing, etc., and one of these methods may be used, or a combination of two or more may be used.

[0123] In the illustrated structure, the sealing portion 4 is formed by thermocompression bonding. This can increase the density of the fibers in the sealing portion 4. Therefore, the outflow of the absorbed ink 100 from the sealing portion 4 can be effectively prevented or suppressed.

[0124] In addition, since at least one of the base layers 2 contains the adhesive described above, the base layers 2 can be bonded by welding such as heat welding. In addition, by appropriately selecting the type, melting point, particle size, and amount of the adhesive contained in each base layer 2, the bonding strength can be easily adjusted.

[0125] When the sealing portion 4 is formed by bonding using an adhesive, the adhesive used is not particularly limited, and a water-soluble adhesive, an organic adhesive, or the like can be used. Among these, a water-soluble adhesive is preferred.

[0126] Examples of water-soluble binders include proteins such as casein, soy protein, and synthetic protein; various starches such as starch and oxidized starch; polyvinyl alcohols including modified polyvinyl alcohol such as polyvinyl alcohol, cationic polyvinyl alcohol, and silyl-modified polyvinyl alcohol; cellulose derivatives such as carboxymethyl cellulose and methyl cellulose; aqueous polyurethane resins, aqueous polyester resins, and the like.

[0127] like Figure 3 As shown, although the width W of the sealing portion 4 when viewed from above is not particularly limited, it is preferably 2 mm or more and 35 mm or less, and more preferably 5 mm or more and 24 mm or less. When the width W of the sealing portion 4 is within such a range, the edge of the base layer 2 can be sealed as necessary and sufficiently.

[0128] The width W of the sealing portion 4 is preferably uniform over the entire circumference of the sealing portion 4 , but is not limited thereto.

[0129] The liquid absorbent 1 described above can be produced by, for example, the following production method.

[0130] First, if Figure 4 As shown, a nonwoven fabric is prepared as the second layer 22 , and a defibrated material 7 of cellulose fibers is deposited on the second layer 22 , thereby obtaining a laminate 9 in which a deposit 8 is stacked on the second layer 22 .

[0131] Next, the laminate 9 is pressed by a pressure roller (not shown) or the like to compress the deposit 8 on the second layer 22, thereby forming the first layer 21. Thus, the base layer 2 can be obtained from the laminate 9. In addition, when the deposit 8 contains a binder, heating may be performed while pressing.

[0132] Through this method, two base layers 2 are manufactured.

[0133] Next, if Figure 5 As shown, water 11 is applied to the surface of the first layer 21 of a base layer 2 by spraying or the like, and then, as shown in FIG. Figure 6 As shown, particles of water-absorbent resin 30 are supplied onto first layer 21. Then, by drying, absorbent layer 3 composed of water-absorbent resin 30 is formed on first layer 21, thereby obtaining laminate 12 in which absorbent layer 3 and one base layer 2 are laminated.

[0134] Next, if Figure 7 As shown in the figure, the laminate 12 is placed in such a manner that the absorbent layer 3 is on the upper side, and the other base layer 2 is attached to the surface of the absorbent layer 3 on the opposite side (upper side) of the base layer 2 in such a manner that the first layer 21 is on the absorbent layer 3 side, and then dried. The surface of the other (upper side) base layer 2 to be attached, especially the attached surface, is previously moisturized.

[0135] Next, if Figure 7 As shown, the seal portion 4 is formed on the two base layers 2, that is, the entire periphery of the edge portion is pressed from above and below using the pressurizing blocks 5 to form the seal portion 4. In this way, the liquid absorbent body 1 can be obtained.

[0136] By replacing the pressurizing block 5 with a heating and pressurizing block, the sealed portion 4 bonded by thermocompression can be formed.

[0137] Although the liquid absorber and the liquid absorber of the present invention have been described above with reference to the illustrated embodiments, the present invention is not limited thereto, and each part constituting the liquid absorber and the liquid absorber can be replaced with any structure that can perform the same function. In addition, any structure can be added.

[0138] Explanation of symbols

[0139] 1…liquid absorber; 2…base layer; 3…absorbent layer; 4…sealing portion; 5…pressurizing block; 6…container; 7…defibrated material; 8…deposited material; 9…laminated body; 10…liquid absorber; 11…water; 12…laminated body; 21…first layer; 22…second layer; 30…water-absorbent resin; 31…upper surface; 32…lower surface; 60…opening; 100…ink.

Claims

1. A liquid absorber, characterized in that: have: an absorbent layer having a water-absorbent resin and having liquid absorbency; a base layer which is laminated on at least one surface side of the absorbent layer and has liquid permeability, The base layer comprises a first layer and a second layer, the first layer comprises cellulose, the second layer is located on a side of the first layer opposite to the absorbent layer, and the gram weight of the second layer is different from the gram weight of the first layer. When the gram weight of the first layer is set to A1 and the gram weight of the second layer is set to A2, A2<A1 is satisfied, wherein the units of A1 and A2 are g / cm 2 .

2. The liquid absorbent according to claim 1, wherein When the density of the first layer is set to B1 and the density of the second layer is set to B2, B2<B1 is satisfied, wherein the units of A1 and A2 are g / cm 3 .

3. The liquid absorbent according to claim 2, wherein: When the thickness of the first layer is T1 and the thickness of the second layer is T2, T1 / T2 is greater than or equal to 1.2 and less than or equal to 5, wherein the units of T1 and T2 are mm.

4. The liquid absorbent according to claim 3, wherein: When the diffusion speed of the liquid in the surface direction of the first layer is C1 and the diffusion speed of the liquid in the surface direction of the second layer is C2, C1<C2 is satisfied, wherein the units of C1 and C2 are mm / s.

5. The liquid absorber according to claim 1, wherein The second layer is non-woven fabric.

6. The liquid absorbent according to claim 4, wherein: The base layer is laminated on the one surface side and the other surface side of the absorbent layer, respectively.

7. The liquid absorbent according to claim 6, wherein: A sealing portion is provided that seals an edge portion of the base layer on the one surface side and an edge portion of the base layer on the other surface side.

8. A liquid absorber, characterized in that: have: The liquid absorbent according to any one of claims 1 to 3; The container accommodates the liquid absorber and has a liquid supply portion to which the liquid is supplied.

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