JP2019070147A - Ink cartridge, and inkjet recording method and method for manufacturing printed matter using the same - Google Patents

Abstract

To provide an ink cartridge for inkjet recording which suppresses thickening or aggregation of a resin emulsion in an ink composition filling a container for ink, and can maintain stability.SOLUTION: An ink cartridge for inkjet recording houses a container 12 for ink filling an ink composition, where the ink composition contains a solvent containing water and an organic solvent, a resin and a surface active agent. The water is 30 pts.mass or more in 100 pts.mass of the ink composition, and at least a part of the resin contained in the ink composition is contained as resin emulsion. A void ratio defined by a ratio of a volume of a void to the total volume of a volume of the ink composition filling the container for ink an a volume of a void contained in the container for ink is 30% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates mainly to an ink cartridge for ink jet recording containing an ink container filled with an ink composition, an ink jet recording method using the same, a method of producing a printed matter, and an ink jet recording apparatus.

  Ink compositions prepared by dissolving various water-soluble dyes in water or a mixture of water and an organic solvent are widely used as ink compositions for ink jet recording. The ink composition is directly discharged onto a substrate such as paper by an ink jet method, and the ink composition is allowed to adhere to dry the mixed liquid, thereby obtaining characters and images.

  Among the above-described ink compositions for ink jet recording, ink compositions containing water as a main component containing 30% by mass or more of water in the ink composition are used. Water has a lower boiling point than the other solvents contained in the ink composition. In addition, water is a solvent that is safe and does not ignite like organic solvents, and is also excellent in environmental aspects.

  In order to expand the application range of the ink composition, attempts have been made to improve the performance of the ink coating film by containing a resin emulsion (latex resin particles) (for example, Patent Documents 1 and 2).

  The resin emulsion (latex resin particles) means an aqueous dispersion in which the continuous phase is a water-soluble solvent and the dispersed particles are resin fine particles. By forming the resin emulsion, the resin can be dispersed in the ink composition as fine resin particles by electrostatic repulsion or steric repulsion.

Japanese Patent Application Publication No. 2008-019431 Japanese Patent Application Laid-Open No. 2007-099913 JP, 2006-007685, A Japanese Patent Application Publication No. 2005-518974 JP, 2013-144774, A JP, 2015-193824, A

  Now, in the ink composition containing the resin emulsion, when the ink composition is applied to the recording medium, the water-soluble solvent contained in the ink composition evaporates or penetrates the recording medium, and the resin on the recording medium Emulsion thickens and aggregates. Thus, the ink composition containing the resin emulsion can fix the coloring material contained in the ink composition to the recording medium.

  On the other hand, the present inventors have found that the ink composition containing the resin emulsion may thicken or coagulate the resin emulsion when filled in an ink container in the ink cartridge and stored for a long period of time. It was done. The ink composition in which the resin emulsion is thickened or aggregated may block the inside of the flow path of the ink jet recording apparatus or the flow path or nozzle of the ink jet head, and may deteriorate the ink jet discharge property of the ink composition.

  The present invention has been made in view of the above-mentioned circumstances, and is for ink jet recording which can maintain stability by suppressing thickening or aggregation of a resin emulsion in an ink composition filled in an ink container. An object of the present invention is to provide an ink cartridge.

  The present inventors diligently studied to solve the above problems. As a result, it has been found that an ink cartridge in which the porosity of the ink container is adjusted can solve the above problems, and the present invention has been completed. Specifically, the present invention provides the following.

(1) An ink cartridge for ink jet recording, which contains an ink container filled with an ink composition,
The ink composition contains a solvent containing water and an organic solvent, a resin, and a surfactant.
The water is 30 parts by mass or more in 100 parts by mass of the ink composition,
At least a portion of the resin contained in the ink composition is contained as a resin emulsion,
The porosity defined by the ratio of the volume of the void to the total volume of the volume of the ink composition filled in the ink container and the volume of the void contained in the ink container is 30% or less Is an ink cartridge.

  (2) The ink cartridge according to (1), wherein the ink container is a flexible container.

  (3) An ink jet recording method of discharging the ink composition filled in the ink container housed in the ink cartridge on the surface of the substrate by the ink jet method using the ink cartridge described in (1) or (2) .

  (4) including the step of discharging the ink composition filled in the ink container housed in the ink cartridge on the surface of the substrate by the ink jet method using the ink cartridge described in (1) or (2) Production method of printed matter.

  (5) An inkjet recording apparatus comprising the ink cartridge according to (1) or (2).

  The ink cartridge of the present invention is an ink cartridge for ink jet recording capable of maintaining stability by suppressing thickening or aggregation of a resin emulsion in an ink composition filled in an ink container.

It is a perspective view of the ink cartridge in which the container for ink of one embodiment of the present invention is stored. It is AA sectional drawing in FIG. 1, Comprising: It is sectional drawing showing the ink and the space | gap in the container for ink.

  Hereinafter, although specific embodiments of the present invention will be described in detail, the present invention is not limited to the following embodiments in any way, and appropriate modifications may be made within the scope of the object of the present invention. can do.

<Ink cartridge>
The ink cartridge 1 of the present embodiment is an ink cartridge for inkjet recording that accommodates an ink container. FIG. 1 shows a perspective view of the ink cartridge 1 of the present embodiment. An ink container 12 is accommodated in an outer frame (case) 11. The ink container 123 is filled with the ink composition 123. The ink cartridge 1 of the present embodiment may have other members as necessary.

  The ink cartridge 1 shown in FIG. 1 uses an outer frame (case) 11 having a certain degree of rigidity and a film of two or more sheets used in a general ink cartridge, and heat sealing the peripheral portion of the film. Although it is an ink cartridge comprised from the container 12 for ink (pouch container) produced, the ink cartridge of this invention is not limited to this aspect. The ink container is not limited to the pouch container, and for example, a flexible container such as a rectangular resin container (for example, a cubicer) that can be folded inward may be used, and the outer frame may be cardboard. A paper container such as may be used.

  In the ink cartridge 1 of the present embodiment, the void ratio of the ink container 12 filled with the ink composition 123 is 30% or less of the total volume of the ink container 12.

  FIG. 2 shows a cross-sectional view of the inside of the ink container 12. When the ink composition 123 containing the resin emulsion is filled in the ink container 12 in the ink cartridge 1 and stored for a long period of time, the ink composition at the interface between the ink composition 123 and the void a in the ink container 12 Thickening or aggregation of the resin emulsion in the substance 123 or coating formation may occur, or the flow path of the ink jet recording apparatus or the flow path or nozzle of the ink jet head may be clogged, or the discharge property may be It has been found by the present inventors that it can be worse.

  Therefore, in the ink cartridge 1 of the present embodiment, the porosity of the ink container 12 is specified to be 30% or less. Therefore, the area of the interface between the ink composition 123 and the void a can be reduced. Further, by setting the porosity of the ink container 12 to 30% or less, the evaporation of the solvent contained in the ink composition is suppressed, and the drying of the ink at the interface between the ink composition 123 and the voids a is suppressed. . As a result, even when the ink container 12 in the ink cartridge 1 is filled and stored for a long period of time, it is possible to prevent the resin emulsion from being thickened, aggregated, or coated. Furthermore, the dissolved gas in the ink composition can be reduced by setting the porosity to 30% or less. Since generation of air bubbles caused by the dissolved gas can be suppressed in the ink jet head, it is possible to suppress deterioration of the storage stability of the ink composition and deterioration of the dischargeability.

  In the present specification, the void ratio means void ratio (%) = volume of void in ink container / ((volume of ink composition in ink container) + (volume of void in ink container) ) It is defined by x100. The volume of the ink composition and the volume of the void are measured by removing the gas and the ink composition from the ink container by using a syringe under atmospheric pressure at room temperature and under the atmospheric atmosphere and measuring the volumes of the ink composition and the void (gas), respectively. Can be asked.

  For example, Patent Document 3 discloses an ink container having a porosity of more than 10% and 50% or less. However, the ink composition filled in the ink container described in Patent Document 3 is a light (ultraviolet) curable ink that is applied on a recording medium and cured by irradiation of light (ultraviolet light) [Document 3 ]. The ink composition according to the present embodiment is a recording medium in which the water-soluble solvent decreases and the resin emulsion thickens and aggregates on the recording medium by evaporation or penetration of the water-soluble solvent into the recording medium. The principle of fixing to the ink composition, and the composition and composition ratio of the ink composition are distinctly different. That is, the ink composition described in Patent Document 3 does not have the problem that the resin emulsion is thickened, aggregated, or formed into a coating in the ink container.

  The ink cartridge according to the present embodiment has a problem in that the discharge property of the ink composition is not deteriorated when the ink composition containing the resin emulsion is filled in the ink container in the ink cartridge and stored for a long time. It is an ink cartridge for ink jet recording in which the porosity of the container for ink was adjusted. Such an ink cartridge is a novel ink cartridge.

  Preferably, the ink cartridge of the present embodiment is removable from an inkjet recording apparatus described later.

[Container for ink]
The ink container 12 provided in the ink cartridge of the present embodiment (hereinafter sometimes referred to as “the ink container 12 according to the present embodiment” or simply “the ink container 12” or the like) It is a container to be stored. The ink container 12 can be filled with a predetermined amount of the ink composition 123, and the ink composition 123 filled in the ink container 12 is supplied to the ink jet head through the ink supply port 122. Do.

  Note that one ink container 12 may be housed in the ink cartridge, or two or more may be housed (not shown). When two or more ink containers are accommodated in the ink cartridge, each ink composition filled in each ink container may be the same or different. Examples of combinations of ink compositions in the case of different types include combinations of ink compositions capable of forming ink coatings of different colors, with different types of colorants contained in the ink composition. .

  Any material may be used as the material of the ink container 12 according to the present embodiment as long as the material can seal the ink composition 123, and from the viewpoint of the barrier property and the processability, it is used for the ink The material of the container 12 is particularly preferably made of a thermoplastic resin.

  As a thermoplastic resin, polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), biaxially stretched nylon 6, polyethylene terephthalate (PET), polycarbonate (PC), polyimide, polyether sulfone (PES), vinylidene chloride polymer, nylon 11, nylon 12, polychlorotrifluoroethylene, polytetrafluoroethylene, polyether ketone, polyphenylene sulfide, polypropylene, low density polyethylene (LDPE), high density polyethylene (HDPE), etc. It can be mentioned.

  As a specific example, a sheet made of a thermoplastic resin, a sheet obtained by laminating a metal foil such as aluminum on these sheets, a sheet obtained by vapor deposition of a metal such as aluminum, these sheets are laminated to another thermoplastic resin The thing which formed the container using the lamination sheet etc. which becomes an independent, etc., and the thing which formed the container using combining several sheets are mentioned.

  Moreover, laminating | stacking a transparent flexible sheet on the upper side or one side via an inorganic substance vapor deposition layer and forming at least one innermost layer by a thermoplastic resin are also mentioned.

  As the inorganic substance vapor deposition film, for example, metals such as aluminum and zinc, inorganic sulfides such as amorphous silica and zinc sulfide, inorganic oxides such as silicon oxide and aluminum oxide, and the like are used.

  The ink container 12 according to the present embodiment is preferably a flexible container. The shape of the ink container 12 is changed by the flexibility according to the amount of the ink composition 123 filled in the ink container 12, and the sealed state of the ink container 12 can be maintained. Also, even if the ink composition 123 filled in the ink container 12 is used and the volume of the ink composition in the ink container is reduced, if the container is a flexible ink container, the volume reduction can be achieved. Accordingly, the shape of the ink container 12 changes so that the volume of the ink container 12 decreases. Therefore, it is possible to suppress an increase in the volume of the void in the ink container due to the atmosphere entering the ink container.

  The shape of the ink container 12 relating to the present embodiment may be a conventionally known shape. For example, a substantially rectangular or elliptical case, a pouch-like pouch container, etc. can be illustrated in front view. A pouch container is a container produced by heat-sealing the peripheral part of a film using at least 2 sheets or more of films.

  The volume of the ink container 12 according to the present embodiment is preferably 0.01 liter or more, and more preferably 0.1 liter or more. The volume of the ink container according to the present embodiment is preferably 10 liters or less and more preferably 5 liters or less.

(Void)
A void a is provided inside the ink container 12 according to the present embodiment. In the present specification, the void means the void in the ink container occupied by the gas such as air other than the ink composition in the ink container.

  Examples of the gas constituting the air gap a can include air, a rare gas such as nitrogen and argon, and the like.

  The porosity (%) of the ink container 12 according to the present embodiment is 30% or less, preferably 20% or less, and more preferably 15% or less.

[Outer frame (case)]
The material of the outer frame (case) 11 according to the present embodiment is not particularly limited, and examples thereof include glasses, metals, and thermoplastic resin. Among them, thermoplastic resins are particularly preferred from the viewpoint of durability, impact resistance, lightness, ease of transportation and cost. Also, it may be a container having a certain degree of rigidity like an outer frame (case) used for a general ink cartridge, or a paper container such as a cardboard may be used.

  As the outer frame (case) 11, for example, an outer frame (case) similar to the case using the upper case and the lower case described in Patent Documents 4 to 6 can be used.

[Ink composition]
The ink composition relating to the present embodiment is an ink composition containing a solvent, a resin, and a surfactant. The solvent also contains water and an organic solvent. Water is 30 parts by mass or more in 100 parts by mass of the ink composition.

  In the ink composition according to the present embodiment, when the content of water in the ink composition is 30 parts by mass or more, the flammability of the ink composition is reduced, and the ink composition becomes a safe ink composition. In addition, since water has a low boiling point, when the content of water in the ink composition is 50 parts by mass or more, the drying property of the ink composition can be improved. The ink composition having a water content of 30 parts by mass or more in the ink composition may be referred to as "ink composition containing water as a main component" or the like.

  Next, each component contained in the ink composition according to the present embodiment will be described.

(solvent)
The solvent contained in the ink composition according to the present embodiment is a solvent containing water and an organic solvent. As water to be contained, it is preferable not to contain various ions, and to use deionized water. The content of water is not particularly limited as long as it is 30 parts by mass or more in 100 parts by mass of the ink composition, but is preferably 40 parts by mass or more in 100 parts by mass of the ink composition. The content is preferably 45 parts by mass or more in 100 parts by mass. When the content of water is 30 parts by mass or more in 100 parts by mass of the ink composition, the flammability of the ink composition is reduced, and the ink composition becomes safe. Further, since water has a low boiling point, the drying property of the ink composition can be improved by the content of water in the ink composition being 30 parts by mass or more.

  The organic solvent to be contained is not particularly limited, and is not particularly limited as long as the design performance of the ink composition according to the present embodiment is not impaired, but the boiling point of the organic solvent is not particularly limited. Is preferably 120 ° C. or higher. Alternatively, the boiling point of the organic solvent is preferably 300 ° C. or less. When the boiling point of the organic solvent contained in the ink composition according to the present embodiment is 120 ° C. or higher, the odor of the ink composition due to the evaporation of the low boiling point solvent can be suppressed, and the organic solvent of the low boiling point component Can reduce the risk of problems caused by swelling or dissolution of the ink jet head or the resin member of the ink jet recording apparatus. Further, by containing an organic solvent having a boiling point of 120 ° C. or more and 300 ° C. or less, the ink composition is not easily repelled even if the substrate is a resin substrate, and an image can be appropriately formed, and the stability of the ink The nozzle moisturizing property and the ejection stability of the ink jet head can be improved. When the boiling point of the organic solvent is 300 ° C. or less, the drying property of the ink composition is improved, and the blocking resistance of the printed matter is improved.

  As an organic solvent of 120 to 300 degreeC, an alkane diol compound and a heterocyclic compound can be mentioned, for example.

  Examples of the heterocyclic compound include 2-pyrrolidone, β-propiolactone, γ-butyrolactone, δ-valerolactone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-imidazolidinone, 1 3, 3-dimethyl-2- imidazolidinone, pyrrolidone carboxylic acid, ethylene carbonate, propylene carbonate, α-lactam, β-lactam, γ-lactam, δ-lactam and the like can be mentioned.

  The alkanediol compound is preferably contained in an amount of 3 parts by mass or more in 100 parts by mass of the organic solvent, and more preferably 10 parts by mass or more in 100 parts by mass of the organic solvent.

  Examples of the alkanediol compound include 2-methyl-1,3-pentanediol, 2-methyl-1,3-propanediol, 1,2-hexanediol, 1,2-butanediol, propylene glycol, diethylene glycol, 1 , 6-hexanediol, 3-methyl-1,5-pentanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentane Diol, 3-methyl-1,3-butanediol, ethylene glycol, 2-methyl-2,4-pentanediol and the like can be mentioned.

  Among the alkanediol compounds, it is preferable to contain 2-methyl-1,3-pentanediol and / or 2-methyl-1,3-propanediol. 2-methyl-1,3-pentanediol and 2-methyl-1,3-propanediol can improve the spread of the ink on the substrate, and the ink fixability to the substrate is also good. It can be

(resin)
The ink composition according to the present embodiment contains a resin. By containing the resin in the ink composition, the fixability and the water resistance of the printed matter are improved. In the ink composition according to the present embodiment, at least a part of the contained resin is contained as a resin emulsion. In the ink composition according to the present embodiment, the resin emulsion means an aqueous dispersion in which the continuous phase is a water-soluble solvent and the dispersed particles are resin fine particles. By forming the resin emulsion, the resin can be dispersed in the ink composition as fine resin particles by electrostatic repulsion or steric repulsion. The resin emulsion generally has the property of thickening and aggregating when the water-soluble solvent, which is a continuous phase, is reduced by evaporation, permeation and the like, and has an effect of promoting the fixing of the coloring material to the substrate.

  When a resin is contained as a binder component in the ink, an ink coating film having good resistance can be formed, but when the content of the water-soluble resin is too large, the water resistance and the discharge stability of the ink coating film become It may decrease. In addition, by using a resin emulsion, a resin of high molecular weight can be contained, and the ink film physical properties can be improved. Therefore, at least a part of the contained resin is preferably contained as a resin emulsion.

  At least a part of the resin contained in the ink composition according to the present embodiment is contained as a resin emulsion. Examples of the resin include acrylic resin, polystyrene resin, polyester resin, styrene acrylic resin, styrene resin, acrylic vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride vinyl vinyl copolymer resin, polyethylene resin, urethane resin, acrylic A polyester resin, a urethane acrylic resin, a silicone (silicon) resin, an acrylamide resin, an epoxy resin, or a copolymer resin or a mixture thereof can be used. In the present invention, acrylic resins, urethane resins, urethane acrylic resins, polyester resins, acrylic polyester resins, styrene acrylic resins, acrylic vinyl chloride resins and the like are preferable, and among them, acrylic resins are preferable. The acrylic resin is not particularly limited as long as it contains, as a main component, a structural unit (acrylic structural unit) derived from a (meth) acrylic acid ester monomer. o-, m-, p-alkyl, nitro, cyano, amide, ester derivative, vinyl aromatic monomer such as vinyl toluene, chlorostyrene, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, citraconic Acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monomethyl ester, itaconic acid monobutyl ester, vinyl benzoic acid, oxalic acid monohydroxyethyl (meth) acrylate, 2-acryloyloxyethyl succinate, Phthalic acid 2-methacryloyl ester It is more preferable that the copolymer includes a repeating unit derived from any of a carboxyl group-containing monomer having an ethylenic unsaturated double bond and a carboxyl group such as xyl ethyl and carboxyl group-terminated caprolactone modified (meth) acrylate. . Thereby, the ink film physical properties in the ink composition can be made better.

  An acrylic resin can be formed using these monomers, but the form of copolymerization of the monomers is not particularly limited. For example, block copolymers, random copolymers, graft copolymers, etc. should be used. Can. The resin emulsion can be produced, for example, by an emulsion polymerization reaction and neutralization after the reaction. As the emulsifying agent, a conventional high molecular weight surfactant may be used, or a reactive surfactant having an unsaturated bond may be used. The synthesis method is not particularly limited, and, for example, water, a monomer, an emulsifier, and polymerization initiation in the presence of a reactive surfactant, a nonreactive surfactant, polyvinyl alcohol, a cellulose derivative, etc. The emulsion polymerization can be carried out by mixing with an agent. The resin emulsion can also be obtained by mixing a resin solution with water together with a surfactant, without causing an emulsion polymerization reaction. For example, it can be obtained by adding and mixing a solution of a resin composed of (meth) acrylic acid ester or styrene and a (meth) acrylic acid ester and a surfactant in water. Furthermore, the above acrylic resin may be copolymerized with resins other than acrylic resin such as urethane resin, polyester resin, styrene resin, vinyl chloride resin, silicone (silicon) resin and the like.

  As a commercially available resin emulsion, for example, Acrit WEM-031 U, WEM-200 U, WEM-321, WEM-3000, WEM-202 U, WEM-3008 (manufactured by Taisei Fine Chemical Co., Ltd., acrylic-urethane resin emulsion), Acrit UW-550CS, UW-223SX, AKW107, RKW-500 (manufactured by Taisei Fine Chemical Co., Ltd., acrylic resin emulsion), LUBRIJET N240 (manufactured by Lubrizol, acrylic resin emulsion), Superflex 150, 210, 470, 500M, 620, 650, E2000, E4800, R5002 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., urethane resin emulsion), bini bran 701 FE 35, 701 FE 50, 701 FE 65, 700, 701, 71 , 737, 747 (manufactured by Nisshin Chemical Co., Ltd., vinyl chloride-acrylic resin emulsion), Vinibran 2706, 2685 (manufactured by Nisshin Chemical Co., Ltd., acrylic resin emulsion), Movinyl 743 N, 6600, 7470, 7720, (Japan Although Synthetic Chemical Co., Ltd. product, an acrylic resin emulsion) etc. can be illustrated, it is not limited to these.

  The average particle diameter of the resin emulsion is preferably 30 nm or more, and more preferably 50 nm or more, from the viewpoint of dispersion stability in the ink composition and inkjet dischargeability. Moreover, 300 nm or less is preferable and 250 nm or less is more preferable. In the present embodiment, the number average particle size of the pigment can be measured using a concentrated particle size analyzer (FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.) at a measurement temperature of 25 ° C.

  From the viewpoint of membrane water resistance, the mass average molecular weight of the resin emulsion is preferably 10000 or more, and more preferably 100000 or more. The mass average molecular weight of the resin emulsion is preferably 1,000,000 or less, more preferably 500,000 or less, from the viewpoint of the stability of the ink composition. In addition, in this embodiment, the molecular weight of resin shows the mass mean molecular weight Mw, is a value measured by GPC (gel permeation chromatography), and it is "HLC-8120GPC" made by Tosoh Corp. The polystyrene standard for calibration curve can be used as a standard.

  The glass transition point (Tg) of the resin emulsion is capable of forming printed matter having water resistance, solvent resistance and scratch resistance even when printed on a low absorbing substrate or non-absorbing substrate, 0 ° C. or higher is preferable because it is possible to avoid applying high temperature to form a printed matter, and to make unnecessary a lot of energy and to make the printing substrate less susceptible to heat damage, 10 degreeC or more is more preferable, and 20 degreeC or more is still more preferable. Moreover, 100 degrees C or less is preferable, 90 degrees C or less is more preferable, and 80 degrees C or less is still more preferable. The glass transition temperature (Tg) can be measured, for example, using a differential scanning calorimeter "DSC-50" manufactured by Shimadzu Corporation.

  The resin emulsion is not limited to any one of cationic, nonionic and anionic, but the acid value of the resin emulsion is 0.01 mg KOH / g or more from the viewpoint of the storage stability of the ink composition and the like. Is preferred. The acid value of the resin emulsion is preferably 25 mg KOH / g or less from the viewpoint of water resistance of printed matter, storage stability of the ink composition, and the like. In the present invention, the acid value refers to the mass (mg) of potassium hydroxide required to neutralize the acidic component contained in 1 g of the sample (solid content of resin), and is described in JIS K 0070. It can be measured by a method according to the method of

  In the ink composition of the present embodiment, the mass part of the resin (resin emulsion) contained in 100 parts by mass of the ink composition is particularly limited as long as a print having desired water resistance and solvent resistance can be formed. Although not preferable, for example, it is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and further preferably 0.5 parts by mass or more in the ink composition. And more preferably 1 part by mass or more. The ink composition preferably contains 25 parts by mass or less, more preferably 20 parts by mass or less, further preferably 15 parts by mass or less, and more preferably 10 parts by mass or less .

[Surfactant]
The ink composition of this embodiment contains a surfactant. The surfactant is not particularly limited, but, for example, an anionic surfactant, a cationic surfactant, a polyoxyalkylene alkyl ether, a polyoxyalkylene benzyl phenyl ether or an acetylene which may be alkylene oxide modified. Nonionic surfactants such as glycol surfactants, and amphoteric surfactants can be mentioned.

  In the ink composition according to the present embodiment, at least one surfactant selected from the group consisting of polyoxyalkylene benzyl phenyl ether, fluorosurfactant, and polysiloxane surfactant may be contained among others. preferable. The stability can be maintained by suppressing thickening or aggregation of the resin emulsion in the ink composition filled in the ink container.

  As polyoxyalkylene benzyl phenyl ether, polyoxyethylene tribenzyl phenyl ether (For example, Kao Corp. make, emulgen B66) etc. can be mentioned, for example.

  Examples of the fluorine-based surfactant include polyoxyalkylene fluorinated alkyl ether, fluorinated alkyl hydrophilic group-containing oligomer, fluorinated alkyl ester addition polymer, etc., among which nonionic polyoxyalkylene fluorinated alkyl ether It is more preferable to contain The wettability and spreadability to the substrate can be further improved. Examples of commercially available fluorine-based surfactants include Megafac (fluorinated surfactants; manufactured by DIC Corporation), Surflon (fluorinated surfactants; manufactured by AGC Seimi Chemical Co., Ltd.), and the like. .

  By containing a polyoxyalkylene fluorinated alkyl ether, even the ink composition of the present embodiment having water as a main component has an effect of greatly reducing the static surface tension, so the static surface tension is in a preferable range. can do. Therefore, as the surfactant contained in the ink composition of the present embodiment, it is preferable to use a surfactant containing a polyoxyalkylene fluorinated alkyl ether.

  As the polysiloxane surfactant, an organically modified polysiloxane surfactant is preferably used, and in the present invention, a polyether group-modified polysiloxane compound having a polyether group can be preferably used.

  As a polysiloxane compound, as a commercial item, for example, FZ-2122, FZ-2110, FZ-7006, FZ-2166, FZ-2164, FZ-7001, FZ-2120, SH 8400, FZ-7002, FZ-2104 8029 ADDITIVE, 8032 ADDITIVE, 57 ADDITIVE, 67 ADDITIVE, 8616 ADDITIVE, 8616 ADDITIVE (all are manufactured by Toray Dow Corning, Inc.), KF-6012, KF-6015, KF-6004, KF-6013, KF-6011, KF-6043 KP-104, 110, 112, 323, 341 (all from Shin-Etsu Chemical Co., Ltd.), BYK-300 / 302, BYK-301, BYK-306, BYK-307, BYK-320, BYK-325. , BYK-330 BYK-331, BYK-333, BYK-337, BYK-341, BYK-342, BYK-344, BYK-345 / 346, BYK-347, BYK-348, BYK-349, BYK-375, BYK-377, BYK-378, BYK-UV 3500, BYK-UV 3510, BYK-310, BYK-315, BYK-370, BYK-UV 3570, BYK-322, BYK-323, BYK-3455, BYK-Silclean 3700 (all are manufactured by Bick Chemie, Inc.) ), Silface SAG 503A, Silface SJM-002, Silface SJM-003 (all from Nisshin Chemical Industry Co., Ltd.), TEGO Twin 4000, TEGO Twin 4100, TEGO Wet 240, TEGO Wet 25 , TEGO Wet 240, (both, Evonik Co., Ltd.) and the like can be given.

  Examples of the polyoxyalkylene alkyl ether include polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, and polyoxyethylene polyoxypropylene alkyl ether. Among them, polyoxyethylene alkyl ether can be preferably used. The stability can be maintained by suppressing thickening or aggregation of the resin emulsion in the ink composition filled in the ink container.

  The polyoxyalkylene alkyl ether is, for example, nonionic P-208, P-210, P-213, E-202S, E-205S, E-215, K-204, K-220, S-207, S-215, A-10R, A-13P, NC-203, NC-207 (manufactured by NOF Corporation), Emulgen 106, 108, 707, 709, A-90, A-60 (manufactured by Kao Corporation), Floren G -70, D-90 (manufactured by Kyoeisha Chemical Co., Ltd.), Poem J-0081HV (manufactured by Riken Vitamins Co., Ltd.), adetol NP-620, NP-650, NP-660, NP-675, NP-683, NP -686, Adekacol CS-141E, TS-230E (manufactured by Adeka Co., Ltd.), etc., Solgen 30V, 40, TW-20, TW-80, Neugen CX-100 (Daiichi Kogyo Co., Ltd. Drugs Ltd.) and the like.

  Specific examples of the alkylene oxide non-modified acetylene glycol surfactant include 2,5-dimethyl-3-hexyne-2,5-diol, 3,6-dimethyl-4-octin-3,6-diol, 2,4,7,9-Tetramethyl-5-decyne-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-butyn-3-ol, 3-methyl Examples include 1-pentin-3-ol, 3-hexyne-2,5-diol, 2-butyne-1,4-diol and the like. Moreover, as a commercial item, Surfynol 61, 82, 104 (all are products made by Air Products) etc. can be used.

  Specific examples of the alkylene oxide-modified acetylene glycol surfactant include Surfynol 420, 440, 465, 485, TG, 2502, Dynol 604, 607 (all manufactured by Air Products), Surfynol SE, MD. -20, Olfin E1004, E1010, PD-004, EXP 4300, PD-501, PD-502, SPC (all from Nisshin Chemical Industry Co., Ltd.), Acetylenol EH, E40, E60, E81, E100, E200 ( Both include Kawaken Fine Chemical Co., Ltd.) and the like.

  These surfactants may be used alone or in combination of two or more. The content of the surfactant is appropriately adjusted in accordance with the ink miscibility, the cleaning property, the wettability to the inner wall of the flow path, and the ink jet discharge property, and preferably 0.05 parts by mass or more in 100 parts by mass of the ink composition. More preferably, it is contained 0.1 mass part or more. In addition, preferably 5 parts by mass or less and 3 parts by mass or less are contained in 100 parts by mass of the ink composition.

(Color material)
The ink composition according to the present embodiment may contain a colorant. As the coloring material, a dye or a pigment generally used in the ink composition can be used. Examples of the pigment include inorganic pigments and organic pigments. These may be used singly or in combination of two or more. The ink composition according to the present embodiment may be a so-called clear ink containing no coloring material.

  Examples of organic pigments include insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine pigments, quinacridone pigments, perylene pigments, dioxazine pigments, nickel azo pigments, isoindolinone pigments, pyranthrone pigments, thioindigo pigments, condensation azo pigments, Examples of the organic solid solution pigment such as benzimidazolone pigment, quinophthalone pigment, isoindoline pigment, quinacridone solid solution pigment, perylene solid solution pigment, and other pigments include carbon black.

  When organic pigments are exemplified by color index (C.I.) numbers, C.I. I. Pigment yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214; I. Pigment red 5, 7, 9, 12, 48, 49, 52, 53, 57, 97, 112, 122, 123, 149, 168, 177, 180, 184, 192, 202, 206, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254; I. Pigment orange 16, 36, 43, 51, 55, 59, 61, 64, 71; I. Pigment violet 19, 23, 29, 30, 37, 40, 50; C.I. I. Pigment blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64; I. Pigment green 7, 36, 58; C.I. I. Pigment browns 23, 25, 26 and the like.

  As the inorganic pigment, for example, barium sulfate, iron oxide, zinc oxide, barium carbonate, barium sulfate, silica, clay, talc, titanium oxide, calcium carbonate, synthetic mica, alumina, zinc flower, lead sulfate, yellow lead, zinc yellow And iron red (red iron oxide (III)), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, inorganic solid solution pigments and the like.

  The average dispersed particle size of the pigment is not particularly limited as long as desired color development is possible. Although it varies depending on the type of pigment, it is preferably 300 nm or less, more preferably 200 nm or less, from the viewpoint of achieving good dispersion stability of the pigment and sufficient coloring power. The thickness is preferably 10 nm or more, and more preferably 30 nm or more. If the average dispersion particle size is 300 nm or less, clogging of the nozzles of the inkjet head is unlikely to occur, and a highly reproducible homogeneous image can be obtained. When the average dispersion particle size is 10 nm or more, the light resistance of the obtained printed matter can be made favorable.

  The content of the pigment is not particularly limited as long as it can form a desired image, and is appropriately adjusted. Specifically, the amount is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more, with respect to 100 parts by mass of the ink composition, although it varies depending on the type of the pigment. The amount is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by mass of the ink composition. When the content of the pigment is 20 parts by mass or less, the balance between the dispersion stability of the pigment and the coloring power can be excellent.

(Pigment dispersant)
The ink composition according to the present embodiment may contain a pigment dispersant. Here, the pigment dispersant means a resin or surfactant having a function of improving the dispersibility of the pigment in the ink by adhering to a part of the pigment surface.

  In the ink composition relating to the present embodiment, the pigment dispersant that can be used is not particularly limited. For example, surfactants such as cationic, anionic, nonionic, amphoteric, silicone (silicon), and fluorinated surfactants can be used. Among the surfactants, polymer surfactants (polymer dispersants) as exemplified below are preferable.

  As a pigment dispersant that can be used in the ink composition according to the present embodiment, a water-soluble polymer dispersant can be preferably used. Examples of water-soluble polymer dispersants include polyester-based, polyacrylic-based, polyurethane-based, polyamine-based and polycaptolactone-based main chains, and an amino group, a carboxy group, a sulfo group and a hydroxy group as side chains. And dispersants having a polar group such as For example, (co) polymers of unsaturated carboxylic acid esters such as polyacrylic acid esters; copolymers of aromatic vinyl compounds such as styrene and α-methylstyrene and unsaturated carboxylic acid esters such as acrylic acid esters; (Partial) amine salt of (co) polymer of unsaturated carboxylic acid such as polyacrylic acid, (partial) ammonium salt or (partial) alkylamine salt; hydroxyl group-containing unsaturated carboxylic acid ester such as hydroxyl group-containing polyacrylic acid ester (Co) polymers and their modified products; polyurethanes; unsaturated polyamides; polysiloxanes; long-chain polyaminoamide phosphates; polyethyleneimine derivatives (poly (lower alkyleneimine) and free carboxyl group-containing polyester Amides obtained by reaction and their bases); polyallylamine derivatives (polyallyl Reaction product obtained by reacting Min with one or more compounds selected from polyester, polyamide or ester and co-condensate of ester (amide of polyester) having free carboxyl group) Etc. Among them, a water-soluble polymer dispersant containing a (meth) acrylic resin is preferable from the viewpoint of the dispersion stability of the ink and the image sharpness of the printed matter.

  Specific examples of the water-soluble polymer dispersant include SMA 1440 made by SARTOMER, SMA 2625, SMA 17352, SMA 3840, SMA 1000, SMA 2000, SMA 3000, JONCRYL 67, JONCRYL 678, JONCRYL586, JONCRYL 680, JONCRYL 682, JONCRYL 690, JONCRYL -JDX5050, EFKA4550, EFKA4560, EFKA4585, EFKA5220, EFKA6230, Lubrizol manufactured SOLSPERSE 20000, SOLSPERSE 27000, SOLSPERSE 41000, SOLSPERSE 41090, SOLSPERSE 43000, SOLSPE SE44000, SOLSPERSE 46000, SOLSPERSE 47000, SOLSPERSE 54000, BYKJET-9150, BYKJET-9151, BYKJET-9170, DISPERBYK-168, DISPERBYK-190, DISPERBYK- 198, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2015, etc. Be These pigment dispersants can be suitably used in the ink composition of the present embodiment.

  A pigment that can be used in the ink composition according to the present embodiment is a pigment dispersion in which a pigment is dispersed in a water-soluble solvent by a pigment dispersant, and a hydrophilic group is directly modified on the surface of the pigment. The pigment dispersion may be a self-dispersed pigment. In the present embodiment, a pigment that can be used in an ink jet recording ink may use a plurality of the aforementioned organic pigments or inorganic pigments in combination, and a pigment dispersion dispersed in a water-soluble solvent by the aforementioned pigment dispersant. And a self-dispersible pigment described later may be used in combination.

(Other additives)
The ink composition according to the present embodiment may further contain conventionally known additives, if necessary. Additives include, for example, viscosity modifiers, surfactants, pH adjusters, surface tension modifiers, leveling agents, antifoaming agents, antioxidants, preservatives, mildewproofing agents, charge control agents, wetting agents, etc. Known additives may be mentioned as optional components.

<Method of Producing Ink Composition>
The method for producing an ink composition according to the present embodiment can be a production method for producing an ink composition by mixing a coloring material, a resin, and a solvent containing water and an organic solvent.

  For example, a method of preparing by adding an organic solvent, water, a coloring material, a resin, a surfactant and other components as necessary, adding a coloring material and a dispersing agent to a solvent containing water and an organic solvent After dispersion, a method of preparing by adding a resin, a surfactant and other components as needed, a solvent containing water and an organic solvent, a coloring material, a resin, a surfactant and other components as needed After adding the components, a method of dispersing and preparing a coloring material may, for example, be mentioned.

<Method of manufacturing container for ink>
The ink container 12 according to the present embodiment can be manufactured, for example, by the following method. First, at least two or more films are used, and a pouch container is manufactured by heat-sealing the periphery of the film. Then, the ink composition 123 prepared as described above is filled in the pouch container so that the porosity is 30% or less.

  A conventionally known method can be used as a method of filling the ink composition 123 into the ink container (pouch container). As a method for degassing the dissolved gas in the ink composition, for example, decompression in a closed container or a hollow fiber degassing module using a hollow fiber membrane in an ink flow path (for example, degassing module SEPAREL manufactured by DIC) Can be done by

<Method of manufacturing ink cartridge>
The method of manufacturing the ink cartridge 1 of the present embodiment is not particularly limited as long as it can be manufactured so as to be able to accommodate the ink container 12 filled with the ink composition 123, and can be manufactured by a conventionally known method. . A part of the ink container 12 and the outer frame (case) 11 accommodating the ink container 12 may be fused or the like.

  As the outer frame (case) 11, the same one as the outer frame (case) described above can be used.

<Ink jet recording apparatus>
In addition, if an inkjet recording device can be equipped with the ink cartridge 1 of said embodiment, the conventionally well-known inkjet recording device can be used. The ink cartridge 1 is preferably removable from the ink jet recording apparatus.

<Ink jet recording method>
In the ink jet recording method using the ink cartridge 1 of the present embodiment, the substrate is not particularly limited, and as described above, any of the absorbent substrate, the low absorbent substrate, and the non-absorbent substrate is suitable. It can be used for

  An ink jet recording method using the ink cartridge 1 of the present embodiment is not particularly limited. For example, the ink container 12 housed in the ink cartridge 1 on the surface of the substrate by the ink jet method on the substrate The inkjet recording method which discharges the ink composition 123 with which it was filled can be mentioned. By using the ink cartridge 1 of the present embodiment, it is possible to realize an ink jet recording method which is excellent in member suitability of the ink jet head and the ink jet recording apparatus and excellent in maintainability.

  The ink cartridge of the present embodiment can be applied to any inkjet recording apparatus such as a piezo system, a thermal system, and an electrostatic system. In any type of ink jet recording apparatus, the resin emulsion in the ink composition in the ink cartridge is thickened, coagulated, or formed into a coating film or the inside of the flow path of the ink jet recording apparatus or the flow path or nozzle of the ink jet head. The clogging can be suppressed, and the deterioration of the dischargeability due to the change of the physical properties of the ink composition can be suppressed.

  Among other things, the ink cartridge of the present embodiment uses a piezoelectric vibrator as a pressure generating element, and a piezoelectric inkjet recording apparatus that discharges ink droplets by pressurizing and decompressing the pressure chamber by deformation of the piezoelectric vibrator. Preferably it is used.

  The piezo method has a longer distance for reciprocating the fluid (ink composition) at a higher speed than the thermal method. Further, with the recent increase in density and accuracy of the ink jet system, the width of the flow path connected to the nozzle is narrowed, and the nozzle hole is reduced in size and in density. Therefore, when the ink composition is discharged by the piezo method, there is a high possibility that problems occur in the discharge of the ink composition. An ink composition containing water as a main component and further containing a resin emulsion and other components (for example, a coloring material) is an ink jet recording apparatus by evaporation (volatilization) of water contained in the ink composition. There is a tendency that the component contained in the ink composition may be generated as precipitates in the vicinity of the interior of the head or the nozzle in the case of the present invention as compared with an ink composition not containing water as a main component.

  However, in the ink cartridge of the present embodiment, since the void ratio of the ink container filled with the ink composition is 30% or less of the total volume of the ink container, the thickening or aggregation of the resin emulsion is suppressed to suppress the ink The stability of the composition can be maintained.

  The type of the ink jet printing method is not particularly limited, and may be a serial head type ink jet method or a line head type ink jet method.

<Production method of printed matter>
Printed matter can be manufactured using the ink cartridge 1 of the present embodiment. For example, there can be mentioned a method for producing a printed matter, which includes the step of discharging onto the surface of a substrate by the inkjet method described above.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these descriptions.

Preparation of Ink Composition
Each ink composition was adjusted as follows using a color material (pigment dispersion), a resin (resin emulsion), water (ion-exchanged water) and an organic solvent. The adjustment method of a pigment dispersion and resin (resin emulsion) is shown below.

1. Preparation of pigment dispersions A to C A pigment dispersion was prepared by the following method.

  A mixture of 90 g of styrene, 15 g of acrylic acid, 15 g of methacrylic acid, 30 g of butyl acrylate and 3.6 g of tert-butylperoxy-2-ethylhexanoate in 200 g of toluene kept at 100 ° C. over 1.5 hours Dripped. After completion of the dropwise addition, the mixture was reacted at 100 ° C. for 2 hours and then cooled to obtain a resin solution. The resin was purified from the resin solution with hexane to obtain a pigment dispersion resin having a molecular weight of 18,000 and an acid value of 65 mg KOH / g.

(Pigment dispersion liquid A)
Add 35.0 g of pigment dispersion resin SOLSPERSE 47000 (molecular weight 280000, acid value 20 mg KOH / g), 15.0 g of PR122 (CI pigment red 122) and 0.05 g of Surfynol 104 PG to 80 g of ion-exchanged water, and add zirconia beads The resultant mixture was dispersed by a paint shaker to obtain a pigment dispersion A (denoted as "pigment A" in Table 1).

(Pigment dispersion liquid B)
In 80 g of ion-exchanged water, 2 g of the pigment dispersant 1 obtained above and 0.2 g of N, N-dimethylaminoethanol are dissolved, and 15.0 g of PR122 (CI pigment red 122) is defoamed. An agent ("Surfinol 104PG" manufactured by Air Products) was added, and the mixture was dispersed by a paint shaker using zirconia beads to obtain a pigment dispersion B (denoted as "pigment B" in Table 1).

(Pigment dispersion liquid C)
In 80 g of ion-exchanged water, 2 g of the pigment dispersant 1 obtained above and 0.2 g of N, N-dimethylaminoethanol are dissolved, and 15.0 g of PBk 7 (C.I. pigment black 7) is defoamed. An agent ("Serfinol 104PG" manufactured by Air Products) was added, and the mixture was dispersed by a paint shaker using zirconia beads to obtain a pigment dispersion C (denoted as "pigment C" in Table 1).

2. Preparation of resin emulsion (Resin emulsion A)
The inside of a flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube and dropping funnel is sufficiently replaced with nitrogen gas, and then a reactive surfactant (Kao Co., Ltd., trade name: Latem PD-) 104) 0.75 g of potassium persulfate, 0.04 g of potassium persulfate, 1 g of methacrylic acid and 150 g of pure water (deionized water) were charged and mixed by stirring at 25 ° C. A mixture of 60 g of methyl methacrylate, 45 g of methyl acrylate, 22.5 g of styrene and 22.5 g of α-methyl-styrene was added dropwise to this to prepare a pre-emulsion. In addition, after the inside of a flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas inlet tube, a reflux tube and a dropping funnel is sufficiently replaced with nitrogen gas, a reactive surfactant (Kao Co., Ltd., trade name: Latemru) 3 g of PD-104, 0.01 g of potassium persulfate and 200 g of pure water (deionized water) were stirred at 70 ° C. and mixed. Thereafter, the prepared pre-emulsion was dropped into the flask over 3 hours. After heat aging at 70 ° C. for 3 hours, it is cooled, adjusted to pH 8 with N, N-dimethylethanolamine, filtered through # 150 mesh (made by Japan Textile), solid content 30 mass%, 500 g Resin emulsion 1 (glass transition temperature: 76 ° C., acid value: 4 mg KOH / g, average particle diameter: 90 nm).

(Resin emulsion B)
The inside of a flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube and dropping funnel is sufficiently replaced with nitrogen gas, and then a reactive surfactant (Kao Co., Ltd., trade name: Latem PD-) 104) 0.75 g, potassium persulfate 0.04 g, acrylic acid 2 g, methacrylic acid 2 g were charged and mixed by stirring at 25 ° C. To this, a mixture of 37 g of butyl methacrylate, 38 g of methyl acrylate and 71 g of methyl methacrylate was dropped to prepare a pre-emulsion. In addition, after the inside of a flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas inlet tube, a reflux tube and a dropping funnel is sufficiently replaced with nitrogen gas, a reactive surfactant (Kao Co., Ltd., trade name: Latemru) 3 g of PD-104, 0.01 g of potassium persulfate and 200 g of pure water (deionized water) were stirred at 70 ° C. and mixed. Thereafter, the prepared pre-emulsion was dropped into the flask over 3 hours. After heat aging at 70 ° C. for 3 hours, it is cooled, adjusted to pH 8 with N, N-dimethylethanolamine, filtered through # 150 mesh (made by Japan Textile), solid content 30 mass%, 500 g Resin emulsion 2 (glass transition temperature 54.degree. C., acid value 19 mg KOH / g, average particle diameter 100 nm).

3. Preparation of Ink The ink composition of Table 1 was prepared using a pigment dispersion, a resin emulsion, a water-soluble solvent, a surfactant, and ion-exchanged water.

In Table 1, "surfactant A" is a polyether-modified polysiloxane (Silface SAG 503A, manufactured by Nisshin Chemical Co., Ltd.).
In Table 1, "Surfactant B" is polyoxyethylene fluorinated alkyl ether (manufactured by AGC Seimi Chemical Co., Ltd., Surfron S-241).
In Table 1, "surfactant C" is polyoxyethylene tribenzyl phenyl ether (Emulgen B66, manufactured by Kao Corporation).

4. Production of Ink Cartridge An ink cartridge was produced using the above-mentioned ink. Specifically, the void ratio (volume of voids in the ink container / ((volume of ink composition in the ink container) + (volume of the voids in the ink container)) × 100) is as shown in Table 2. As described above, by using a laminated film laminated in the order of an ink container (polyethylene terephthalate / aluminum vapor deposition / polyethylene, heat sealing the peripheral portion of the laminated film so that the polyethylene laminated surfaces of the two laminated films face each other) The above ink composition was filled in the prepared pouch container at room temperature (about 25 ° C.) under atmospheric pressure and atmospheric atmosphere. The volume of the ink container is 1 liter. Then, the ink container filled with the ink composition was housed in a cartridge, and the ink cartridges of Examples and Comparative Examples were manufactured. And the ink cartridge of an Example and a comparative example was stored for 1 month, and the following evaluation was performed.

[Evaluation]
The ink composition was removed from the ink cartridges of the Examples and Comparative Examples stored at room temperature for 1 month using a syringe, filled in an ink jet printer, and printing was performed to evaluate each item. Specifically, a piezo inkjet printer (Seiko Epson PX-105) on OK top coat + (coated paper; manufactured by Oji Paper Co., Ltd.) and IMAGin JT 5829 R (polyvinyl chloride film: manufactured by MAC tac) Hereinafter, printing was performed by printing using a printer A) and a thermal inkjet printer (iP 7230 manufactured by Canon Inc.) (hereinafter referred to as a printer B). Each evaluation was evaluated by the following evaluation criteria. The evaluation results are shown in Table 2.

[Discharge recovery evaluation]
The ejection recovery test was conducted on the ink composition filled in the ink container in the ink cartridge of the example and the comparative example. Specifically, the nozzle on which the ink composition was printed by the printer A was cleaned after being left for 1 hour, and the discharge state was confirmed. A and B are the actual use range.
A: Cleaning was performed from all the nozzles 5 times or less.
B: Cleaning was performed from all the nozzles at five or more and less than ten times.
C: Even if the cleaning was repeated 10 times or more, there were nozzles which were bent or not discharged.

[Discharge stability evaluation]
The ejection stability test was conducted on the ink composition filled in the ink container in the ink cartridge of the example and the comparative example. Specifically, the ink composition was continuously printed for 3 hours with the printer B, and the number of nozzles that were bent or not ejected was confirmed. A and B are the actual use range.
A: The number of curved or non-ejection nozzles is less than 1% of all the nozzles.
B: The number of curved or non-ejection nozzles is 1% or more and less than 3% of all the nozzles.
C: The number of curved or non-ejection nozzles is 3% or more in all the nozzles.

[Filterability evaluation]
The filterability test was conducted on the ink composition which was filled in the ink container in the ink cartridge of the example and the comparative example and stored at room temperature for 1 month. Specifically, 10 ml of the ink composition was subjected to a filtration test using a filter with a pore diameter of 10 μm and a diameter of 25 mm. A and B are the actual use range.
A: It passed without any problem.
B: The filtration rate was slightly reduced, but all the material passed.
C: The filtration rate was significantly reduced.

  From Table 2, the ink cartridges of Examples 1 to 8 in which the void ratio of the ink container is 30% or less have the ejection stability and ejection recovery property despite being stored for one month after being filled with the ink composition. And filterability are both good. On the other hand, in the ink cartridges of Comparative Examples 1 to 5 in which the void ratio of the ink container is more than 30%, the ejection stability, the ejection recovery property and the filterability decrease and the viscosity of the ink composition increases with time. It is inferred.

  In the ink cartridge of the present invention, the ink cartridge of the present invention can maintain stability by suppressing thickening or aggregation of a resin emulsion in an ink composition filled in an ink container. Was confirmed.

1 Ink cartridge 11 Outer frame (case)
12 Container for ink 121 Outer frame of container for ink 122 Ink supply port 123 Ink composition a Void

Claims (5)

An ink cartridge for ink jet recording, which accommodates an ink container filled with an ink composition, comprising:
The ink composition contains a solvent containing water and an organic solvent, a resin, and a surfactant.
The water is 30 parts by mass or more in 100 parts by mass of the ink composition,
At least a portion of the resin contained in the ink composition is contained as a resin emulsion,
The porosity defined by the ratio of the volume of the void to the total volume of the volume of the ink composition filled in the ink container and the volume of the void contained in the ink container is 30% or less Is an ink cartridge.   The ink cartridge according to claim 1, wherein the ink container is a flexible container.   The inkjet recording method which discharges the ink composition with which the ink container accommodated in the said ink cartridge was filled with the ink cartridge by the inkjet system using the ink cartridge of Claim 1 or 2 by the inkjet system.   A method for producing a printed matter, comprising the step of discharging the ink composition filled in the ink container housed in the ink cartridge onto the surface of the substrate by an ink jet method using the ink cartridge according to claim 1 or 2.   An ink jet recording apparatus comprising the ink cartridge according to claim 1.

Images