JP2009000893A - Ink cartridge for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a good liquid receiving container which is strong to the impact and inertial force applied to a container body, and change of internal-and-external-pressure and can delay the time for the liquid accumulated in an air chamber to flow out from the interconnecting opening at the side where atmospheric air flows in. <P>SOLUTION: The ink cartridge comprises an ink-housing chamber 23 for housing an ink provided in a container body 21, an ink supply section 25 interconnecting to the ink-housing chamber 23, an atmospheric opening channel 102 for introducing air into the ink chamber 23 from an atmospheric opening hole opened to the outside with the consumption of an ink in the ink chamber-housing chamber 23, and an air chamber 31a which is provided in the middle of the atmospheric opening channel 102 and can store an ink entering the atmosphere opening channel 102. The interconnecting opening 79 of the air chamber 31a at the side where atmospheric air flows in is opened at the tip end surface of a projection 95 projected from the inner wall surface of the air chamber 31a. As for the foamability of an ink, the height of a foam after 5 minutes at 25°C according to JIS K3362 is 50 mm or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink cartridge in which an air chamber is interposed between an ink accommodated in a container and an ink accommodating portion and an air opening hole.

  Ink cartridges that are detachably mounted on the carriage of an ink jet printer are used to communicate with the outside of the ink chamber to the atmosphere in order to maintain the internal pressure of the ink chamber (liquid storage portion) in an appropriate state. There are known those provided with an open air channel. And in this kind of air opening flow path, a device for preventing ink leakage from the air opening hole is required.

  Therefore, in the configuration of the open air flow path in the conventional ink cartridge, the ink chamber for storing the ink, the communicating path portion (snake path) formed in a meandering state, and the air chamber (also referred to as an ink trap) capable of storing the infiltrated ink. And an air opening hole for sequentially connecting the ink chamber to the outside and introducing external air into the ink chamber as the ink in the ink chamber is consumed (see, for example, Patent Document 1). ).

  For example, as shown in FIG. 10, the air chamber 1 of the air release channel in the conventional ink cartridge communicates with an end 2a on the air release hole side of the air release groove 2 communicating with an ink chamber (not shown). The air chamber 1 is formed by a cylindrical recess 5 having a predetermined depth obtained by digging a case lid (container main body) 3 in a direction orthogonal to the surface 3 a, and an upper end opening is exposed on the surface 3 a of the case lid 3. Yes. A small-diameter communication port 7 is coaxially formed at the center of the circular lower end surface of the recess 5, and the lower end of the communication port 7 communicates with the ink trap 9 on the atmosphere opening hole side.

  A sealing label (sealing member) 11 is affixed to a portion of the surface 3 a of the case lid 3 where the recess 5 is formed. Thereby, the upper end opening of the recess 5 is sealed, and the air chamber 1 is partitioned and formed.

  In the air chamber 1, when the air in the ink chamber is thermally expanded due to a change in the environmental temperature or the like, the ink leaks to the outside when the ink in the ink chamber flows backward toward an air opening hole (not shown) due to the thermal expansion of the air. It is provided to prevent this.

  Therefore, the ink collected in the air chamber 1 through the corners of the air release groove 2 by capillary attraction enters the communication port 7 to form a meniscus, thereby preventing the ink trap 9 from entering.

JP-A-2005-22340

  However, the ink in the cartridge bubbles due to the ink cartridge falling, the ink cartridge being attached to or detached from the carriage, or the impact or vibration such as the posture change during transportation or movement, and the air chamber 1 is filled with the ink or the bubbles, and is in communication. When the ink and its bubbles reach 7, the meniscus formed at the communication port 7 as described above is easily broken.

  On the other hand, in order to increase the meniscus force, the hole diameter of the communication port 7 needs to be, for example, several tens of μm or less, which is not realistic.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a good ink cartridge capable of delaying the time for the ink accumulated in the air chamber to flow out of the communication port on the air inflow side.

  The above object of the present invention is to provide ink contained in a container, an ink containing part provided in the container for containing ink, an ink supply part communicating with the ink containing part, and consumption of ink in the ink containing part. Accordingly, an air release channel that introduces the atmosphere into the ink container through an air release hole that opens to the outside, and an air that is provided in the middle of the air release channel and that can store ink that has entered the atmosphere release channel. An ink cartridge provided with a chamber, wherein a communication port on the air inflow side of the air chamber is opened at a front end surface of a protrusion protruding from an inner wall surface of the air chamber, and the ink accommodated in the container The foam height after 5 minutes at 25 ° C. based on JISK3362 is achieved by 50 mm or less.

  According to the ink cartridge having the above configuration, even if the ink in the ink containing portion passes through the communication port on the air outflow side of the air chamber and accumulates in the air chamber, the time until the liquid reaches the communication port on the air inflow side is long. It becomes slower by the height of the protrusion.

  That is, in a container leaving state where the communication port on the atmosphere inflow side faces in the vertical direction, the ink that has flowed into the air chamber accumulates up to the height of the protrusion and then flows out from the communication port on the atmosphere inflow side that opens at the tip of the protrusion. . Thereby, the time until the ink flows out from the communication port on the air inflow side is delayed.

  Also, even if the ink is bubbled due to the impact of the container body dropping, attachment / detachment, change in posture during movement, inertia force due to carriage operation, etc., the bubble disappears immediately, so the air flowing into the tip of the protrusion also flows into the atmosphere Since it is difficult for ink to reach the communication port on the side, ink leakage from the communication port on the air inflow side in the air chamber can be stably prevented.

  The ink contained in the container preferably contains at least water, a colorant, and water-insoluble polymer particles, and more preferably contains a water-insoluble organic compound.

  In the ink cartridge having the above-described configuration, a gas-liquid separation membrane that allows passage of gas but does not allow passage of liquid is provided in the middle of the atmosphere opening flow path on the atmosphere opening hole side from the air chamber. desirable.

  According to the ink cartridge having such a configuration, the liquid can be reliably prevented from leaking to the outside by the gas-liquid separation film. In addition, since liquid leakage from the air chamber is stably prevented, the gas-liquid separation membrane can gain time until it comes into contact with the ink and the ventilation performance deteriorates. Can be maintained.

  Further, in the ink cartridge having the above-described configuration, it is preferable that a communicating path portion formed in a meandering state is provided in the middle of the atmosphere opening flow path on the atmosphere opening hole side from the gas-liquid separation film.

  According to the ink cartridge having such a configuration, an effect of delaying the leakage of the liquid to the outside can be expected by the communicating path portion formed in a meandering state, and the air flow between the gas-liquid separation film and the air opening hole is estranged. By doing so, ink evaporation can be reduced.

  In addition, the leakage of ink from the air chamber is delayed and the leakage of ink to the outside is reliably prevented by the gas-liquid separation membrane, so that the ink enters the communication path and the dynamic pressure on the ink supply section changes significantly. I will not let you.

  In the ink cartridge having the above-described configuration, it is preferable that a plurality of the air chambers are provided and adjacent air chambers are communicated with each other.

  According to the ink cartridge having such a configuration, it is easy to secure the volume of the entire air chamber for storing ink even in a limited space in the container body.

  In addition, since the communication port on the air inflow side of each air chamber is opened at the front end surface of the protrusion protruding from the inner wall surface of each air chamber, the time until the ink flows out from the communication port on the most air inflow side can be reduced. Further delays can be made. Furthermore, by opening each communication port in a different direction as appropriate, it is possible to cope with various container leaving postures, and it is possible to reliably prevent ink leakage from the air chamber.

  In the ink cartridge configured as described above, it is preferable that the communication port on the air outflow side of the air chamber is opened on the same plane as the inner wall surface of the air chamber.

  According to the ink cartridge having such a configuration, the communication port on the air inflow side in the air chamber has a trap structure that makes it difficult for liquid to flow out, whereas the communication port on the air outflow side has a structure that allows easy ink intrusion. It becomes. Therefore, the ink accumulated in the air chamber easily passes through the communication port on the air outflow side, which is easy to enter, and is easily collected again into the ink containing portion.

  In the ink cartridge having the above-described configuration, the water-insoluble polymer particles may be water-insoluble polymer particles obtained by copolymerizing a monomer mixture containing a salt-forming group-containing monomer and a macromer and / or a hydrophobic monomer. preferable.

  The water-insoluble organic compound has two or more ester or ether bonds in the molecule, and / or one or more ester or ether bonds in the molecule, a carboxy group, and a sulfonic acid group. It is preferably an ester or ether compound having at least one functional group selected from the group consisting of a phosphate residue, a carbonyl group, an epoxy group and a hydroxyl group.

  According to the ink cartridge having such a configuration, in a container leaving state in which the protrusion is directed vertically, the ink that has been scooped up on the side surface of the protrusion due to surface tension is applied to the tip surface of the protrusion by the corner of the edge portion. The wraparound is prevented. Therefore, even if ink accumulates in the air chamber, the ink does not enter the communication port on the air inflow side at the protruding height of the protrusion. In addition, a section is a corner means that there is no R or chamfering at the edge portion where the tip surface and the side surface of the protrusion intersect.

  According to the ink cartridge having such a configuration, even when ink is accumulated in the air chamber or bubbles due to an impact caused by dropping, attachment / detachment of the container body, a change in posture during movement, an inertial force caused by the carriage operation, or the like, quickly. Due to the defoaming, it is difficult for the ink to come into contact with the front end surface of the protrusion, and it is difficult for the ink to enter the communication port opened in the front end surface.

  According to the ink cartridge of the present invention, even if the liquid in the ink containing portion passes through the communication port on the air outflow side of the air chamber and accumulates in the air chamber, the time until the liquid reaches the communication port on the air inflow side. Can be delayed by the height of the protrusion.

  In addition, the ink cartridge according to the present invention has a conventional communication in which ink is easily broken by foaming due to an impact caused by dropping, attaching or detaching the container body, a change in posture during movement, an inertial force caused by a carriage operation, or the like. Unlike the meniscus formed in the mouth, it is possible to stably prevent ink leakage from the communication port on the air inflow side in the air chamber.

  Accordingly, it is possible to provide a good ink cartridge that is strong against impacts on the container body, inertial force, and internal / external pressure changes, and can delay the time that the ink accumulated in the air chamber flows out from the communication port on the air inflow side.

  The ink used in the ink cartridge of the present invention is an ink containing at least water, a colorant, water-insoluble polymer particles, and a water-insoluble organic compound.

  The water-insoluble organic compound used in the present invention can suppress foaming of aqueous ink. That is, since it is difficult to dissolve in the liquid component water of the water-based ink, the generation of bubbles on the ink surface can be suppressed, and even if bubbles are generated, the bubbles can be quickly eliminated. And the characteristic that the plasticity which improves the softness | flexibility of a polymer particle by providing at least one part in a polymer particle is provided can also be provided. The water-insoluble organic compound imparts flexibility to the polymer particles, so that the polymer particles in the ink are easily fused to each other on the recording paper, and the glossiness and image clarity of the obtained printed matter are improved. It also has the effect.

  The water-insoluble organic compound preferably has a molecular weight of 100 to 2,000, more preferably a molecular weight of 100 to 1,000, in order to effectively suppress foaming and to improve the gloss of printed matter.

  The water-insoluble organic compound is preferably an ester compound, an ether compound, or a sulfonic acid amide compound so that the water-insoluble organic compound is easily contained in the polymer particles, and the ester or ether compound having two or more ester or ether bonds in the molecule. And / or one or more functional groups selected from the group consisting of a carboxyl group, a sulfonic acid group, a phosphoric acid residue, a carbonyl group, an epoxy group, and a hydroxyl group in the molecule with one or more ester or ether bonds. One or more ester or ether compounds are more preferred. The number of ester or ether bonds of the compound is preferably 2 to 3. The number of ester or ether bonds of the compound is preferably 1 to 3. The number of functional groups is preferably 1 to 3. A phosphoric acid residue means the remaining phosphoric acid group in which a part of phosphoric acid was esterified or etherified.

  Among these, an ester obtained from a monovalent carboxylic acid or a salt thereof and a polyhydric alcohol, an ester obtained from a polyvalent acid (polycarboxylic acid, phosphoric acid) or a salt thereof and a monohydric alcohol, or a polyhydric alcohol Ether compounds are preferred, and it is more preferred to have two aliphatic or aromatic carboxylic acid ester groups or three phosphoric acid ester groups. Examples of the salt include alkali metal salts, alkanolamine salts, ammonium salts and the like.

  As the monovalent carboxylic acid, a linear or branched aliphatic carboxylic acid having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms (for example, acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, Linear aliphatic carboxylic acids such as palmitic acid, branched aliphatic carboxylic acids such as pivalic acid, unsaturated aliphatic carboxylic acids such as acrylic acid and methacrylic acid), and aromatic carboxylic acids having 6 to 12 carbon atoms (for example, As the polyvalent acid, an aliphatic or carboxylic acid having 2 to 12 carbon atoms such as maleic acid, fumaric acid, itaconic acid, succinic acid, adipic acid or sebacic acid; phthalic acid, trimellitic acid C6-C12 aromatic carboxylic acid, phosphoric acid, etc., such as an acid, are mentioned.

  The monohydric alcohol is a linear or branched aliphatic alcohol having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms (for example, ethyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, decyl alcohol, dodecyl alcohol). , Aromatic alcohols having 6 to 12 carbon atoms (for example, phenol), and polyhydric alcohols having 2 to 12 carbon atoms such as ethylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, and glycerin. A polyhydric alcohol is mentioned. A saturated or unsaturated fatty acid or alcohol can be used.

  Specific examples of the water-insoluble organic compound include aliphatic carboxylic acid ester, aromatic carboxylic acid ester, phosphoric acid ester, cycloalkane (ken) carboxylic acid ester, oxy acid ester, glycol ester, epoxy ester, sulfonamide, and polyester. Glyceryl alkyl ether, glyceryl alkyl ester, glycol alkyl ether, glycol alkyl ester, trimethylolpropane ether or ester, pentaerythritol ether or ester, and the like.

  The aliphatic carboxylic acid ester is preferably an aliphatic di- or tricarboxylic acid ester from the viewpoint of image clarity.

  Specific examples of the aliphatic dicarboxylic acid ester include dimethyl adipate, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis (butyldiethylene glycol) adipate, dimethyl sebacate, diethyl seba Examples thereof include aliphatic dibasic acid esters such as keto, dibutyl sebacate, bis (2-ethylhexyl) sebacate, diethyl succinate and bis (2-ethylhexyl) azelate.

  Specific examples of aromatic carboxylic acid esters include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, bis (2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, octyl benzyl phthalate, nonyl Phthalic acid esters such as benzyl phthalate, stearyl benzyl phthalate, octyl decyl phthalate, dicyclohexyl phthalate, diphenyl phthalate, bis (dimethylcyclohexyl) phthalate, bis (t-butylcyclohexyl) phthalate, ethyl phthalyl ethyl glycolate, dibutyl trimellitate, Trimellitic acid esters such as diisobutyl trimellitate and tris (2-ethylhexyl) trimellitate It is below. Among these, 3 carbon atoms such as phthalic acid diester having an aliphatic alcohol residue having 1 to 5 carbon atoms such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, octyl benzyl phthalate, nonyl benzyl phthalate, stearyl benzyl phthalate Particularly preferred are benzyl phthalate having an alkyl group of -18, and trimellitic acid diester having an aliphatic alcohol residue of 3 to 5 carbon atoms such as dibutyl trimellitate and diisobutyl trimellitate. The aromatic carboxylic acid ester is preferably an aromatic di- or tricarboxylic acid ester.

  Specific examples of phosphate esters include tributyl phosphate, tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl A phosphate etc. are mentioned.

  Specific examples of the cycloalkane (ken) dicarboxylic acid ester include cyclohexane esters such as 1,2-cyclohexanedicarboxylic acid dibutyl ester and 1,2-cyclohexanedicarboxylic acid diisononyl ester, 3,4-cyclohexene dicarboxylic acid dibutyl ester, 3 Cyclohexene esters such as 1,4-cyclohexenecarboxylic acid diisononyl ester.

  Specific examples of the oxyester include triethyl acetylcitrate, tributyl acetylcitrate, methyl acetylricinoleate and the like.

  Specific examples of the glycol ester include diethylene glycol dibenzoate and triethylene glycol di (2-ethylhexoate).

  Specific examples of the epoxy ester include butyl epoxy stearate and octyl epoxy stearate.

  Specific examples of the sulfonamide include o- and p-toluenesulfonamide, N-butylbenzenesulfonamide and the like.

  Specific examples of the polyester include poly (1,2-butanediol adipate), poly (1,3-butanediol adipate) and the like.

  Specific examples of the glyceryl alkyl ether include glyceryl monoether, glyceryl diether, and glyceryl triether. In these, the glyceryl monoether which has a C8-C30 linear or branched alkyl group is preferable. The alkyl group has 8 to 30 carbon atoms, preferably 8 to 22 carbon atoms, and more preferably 8 to 14 carbon atoms.

  Specific examples of the glyceryl alkyl ester include glyceryl monoalkyl ester, glyceryl dialkyl ester, and glyceryl trialkyl ester.

  Specific examples of the glycol alkyl ether include glycol monoalkyl ether and glycol dialkyl ether.

  Specific examples of glycol alkyl esters include glycol monoalkyl esters and glycol dialkyl esters.

  Said water-insoluble organic compound can be used individually or in mixture of 2 or more types.

  In the present invention, the water-insoluble polymer particles are used for improving printing density, glossiness, and image clarity by interaction with a water-insoluble organic compound.

  This polymer is preferably a water-insoluble polymer in order to easily contain a water-insoluble organic compound.

  Examples of water-insoluble polymers include water-insoluble vinyl polymers, water-insoluble ester polymers, water-insoluble urethane polymers, and the like. Among these, water-insoluble vinyl polymer particles obtained by addition polymerization of vinyl monomers (vinyl compounds, vinylidene compounds, vinylene compounds) are particularly preferable.

  The water-insoluble polymer used as the water-insoluble polymer particles is preferably a water-insoluble polymer obtained by copolymerizing a monomer mixture containing a salt-forming group-containing monomer, a macromer, and / or a hydrophobic monomer.

  The salt-forming group-containing monomer is used from the viewpoint of enhancing the dispersion stability of the resulting dispersion. Examples of the salt-forming group include a carboxy group, a sulfonic acid group, a phosphoric acid group, an amino group, and an ammonium group.

  Examples of the salt-forming group-containing monomer include cationic monomers and anionic monomers, and examples include unsaturated amine-containing monomers and unsaturated ammonium salt-containing monomers.

  Representative examples of anionic monomers include unsaturated carboxylic acid monomers, unsaturated sulfonic acid monomers, unsaturated phosphoric acid monomers, and the like.

  Examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and 2-methacryloyloxymethyl succinic acid. Examples of the unsaturated sulfonic acid monomer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) acrylate, bis-3-sulfopropyl) -itaconic acid ester, and the like. Examples of unsaturated phosphoric acid monomers include vinylphosphonic acid, vinyl phosphate, bis (methacryloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxy Examples thereof include ethyl phosphate.

  Macromers are used from the viewpoint of enhancing the dispersion stability of polymer particles, particularly when the polymer particles contain a pigment. The macromer includes a macromer which is a monomer having a polymerizable unsaturated group having a number average molecular weight of 500 to 100,000, preferably 1,000 to 10,000. Among the macromers, styrenic macromers and aromatic group-containing (meth) acrylate macromers having a polymerizable functional group at one end are preferable from the viewpoint of dispersion stability of polymer particles.

  Examples of the styrenic macromer include a styrene monomer homopolymer or a copolymer of a styrene monomer and another monomer. Examples of the styrene monomer include styrene, 2-methylstyrene, vinyl toluene, ethyl vinyl benzene, vinyl naphthalene, chlorostyrene, and the like.

  Examples of the aromatic group-containing (meth) acrylate-based macromer include a homopolymer of an aromatic group-containing (meth) acrylate or a copolymer thereof with another monomer.

  Hydrophobic monomers are used from the viewpoint of improving printing density, glossiness, and image clarity. Examples of the hydrophobic monomer include alkyl (meth) acrylates and aromatic group-containing monomers.

  As the alkyl (meth) acrylate, those having an alkyl group having 1 to 22 carbon atoms, preferably 6 to 18 carbon atoms are preferable. For example, methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meta) ) Acrylate, (iso or tertiary) butyl (meth) acrylate, (iso) amyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) Examples include decyl (meth) acrylate, (iso) dodecyl (meth) acrylate, and (iso) stearyl (meth) acrylate.

  As the aromatic group-containing monomer, a vinyl monomer having an aromatic group having 6 to 22 carbon atoms, preferably 6 to 12 carbon atoms, which may have a substituent containing a hetero atom, is preferable. Examples thereof include styrene monomers and the aforementioned aromatic group-containing (meth) acrylates. The above-mentioned thing is mentioned as a substituent containing a hetero atom.

  The monomer mixture may further contain nonionic (meth) acrylate monomers, and typical examples thereof include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, ethylene glycol / propylene glycol. (Meth) acrylate etc. are mentioned.

  Examples of the colorant used in the present invention include a cyan pigment, a yellow pigment, and a magenta pigment.

  Examples of cyan pigments include C.I. I. Pigment blue 1, 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, and C.I. I. Bat Blue 4, 60 and the like. These cyan pigments can be used alone or in combination of two or more.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 35, 37, 42, 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 147, 150, 153, 155, 174, 180, 188, 198 and the like. These yellow pigments can be used alone or in combination.

  Examples of magenta pigments include C.I. I. Pigment Red, 1, 3, 5, 8, 9, 16, 17, 19, 22, 38, 57: 1, 90, 112, 122, 123, 127, 146, 184, 202, 207, 209, and C.I. I. Pigment violet 1, 3, 5: 1, 16, 19, 23, 38 and the like. These magenta pigments may be used alone or in combination of two or more.

  Any pigment that is not described in the color index can be used as long as it is insoluble in water.

  The blending amount of the colorant used in the ink composition according to this embodiment is preferably 0.1% by weight to 15% by weight, more preferably 0%, from the viewpoint of color developability and clogging recovery. .5 wt% to 8 wt%.

  The ink composition according to this embodiment includes water as a main solvent. As water, it is preferable to use pure or ultrapure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria is prevented over a long period of time.

  In the ink composition according to this embodiment, it is preferable to add a penetration accelerator from the viewpoint of improving the wettability to the recording medium and increasing the permeability of the organic pigment. The penetration enhancer preferably contains 1,2-alkanediol and / or glycol ether. Specific examples of 1,2-alkanediol include 1,2-octanediol, 1,2-hexanediol, 1,2-pentanediol, 4-methyl-1,2-pentanediol and the like. Specific examples of the glycol ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether. , Ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol monobutyl ether, 1-methyl -1-methoxybutanol, propylene glycol Monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, di Examples include propylene glycol mono-n-propyl ether and dipropylene glycol mono-iso-propyl ether. These solvents can be used singly or in combination of two or more, and are preferably contained in the ink composition in an amount of 2% by weight to 15% by weight from the viewpoint of ensuring appropriate permeability and drying properties.

  Furthermore, other preferable examples of the penetration enhancer include a surface tension adjusting agent. As the surface tension adjusting agent, acetylene glycol surfactants and polyether-modified siloxanes are preferable. Examples of acetylene glycol surfactants include Surfynol 420, 440, 465, 485, 104, STG (product of Air Products), Olphine PD-001, SPC, E1004, E1010 (product of Nissin Chemical Industry Co., Ltd.) ), Acetylenol E00, E40, E100, LH (product of Kawaken Fine Chemical Co., Ltd.) and the like. Examples of the polyether-modified siloxanes include BYK-346, 347, 348, and UV3530 (Bic Chemie product). One or more of these can be used in the ink composition, and the surface tension is preferably adjusted to 20 mN / m to 40 mN / m. In the ink composition, 0.1% by weight to 3% is preferable. 0.0% by weight is contained.

  In addition, it is preferable to add a wetting agent to the ink composition according to this embodiment from the viewpoint of preventing the ink composition from drying and preventing clogging at the head of the ink jet printer. Examples of the wetting agent include glycerin, 1,2,6-hexanetriol, trimethylolethane, trimethylolpropane, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol and dipropylene glycol. Polyhydric alcohols such as 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, glucose, mannose, fructose, ribose, xylose, arabinose , Sugars such as galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, sugar alcohols, hyaluronic acids, 1,2-dimethyl C1-C4 alkyl alcohols such as ruurea, ureas, ethanol, methanol, butanol, propanol, isopropanol, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone , Formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, sulfolane and the like. These can be used singly or in combination of two or more in the ink composition, and in the ink composition from the viewpoint of ensuring appropriate physical properties (such as viscosity), printing quality, and reliability of the ink composition. Is preferably contained in an amount of 10 to 50% by weight.

  Furthermore, a material selected from pH adjusters, preservatives, fungicides, rust inhibitors, dissolution aids, antioxidants, and the like can be added to the ink composition according to the present embodiment as desired. These components can be used alone or in combination of two or more. Moreover, it is not necessary to add, if it is not necessary to add. Those skilled in the art can use the preferable additive selected in a preferable amount as long as the effects of the present invention are not impaired.

  As the pH adjuster, it is possible to use alkali metal hydroxides such as lithium hydroxide, potassium hydroxide and sodium hydroxide, amines such as ammonia, triethanolamine, tripropanolamine, diethanolamine and monoethanolamine. Preferably, it contains at least one pH adjusting agent selected from alkali metal hydroxides, ammonia, triethanolamine, and tripropanolamine, and is preferably adjusted to pH 6-10. If the pH is out of this range, the material constituting the ink jet printer will be adversely affected, and the clogging recoverability will deteriorate.

  Examples of the antiseptic or antifungal agent include sodium benzoate, sodium pentachlorophenol, 2-pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, and 1,2-dibenzisothiazoline-3- ON (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN (trade name) and the like of AVECIA can be exemplified, but not limited thereto.

  The dissolution aid is an additive for dissolving the insoluble matter and keeping the ink composition in a uniform solution when the insoluble matter is precipitated from the ink composition. Examples of solubilizers include pyrrolidones such as N-methyl-2-pyrrolidone and 2-pyrrolidone, ureas such as urea, thiourea and tetramethylurea, allophanates such as allophanate and methyl allophanate, biuret, dimethylbiuret, Biurets such as tetramethyl biuret can be exemplified, but not limited thereto.

  Examples of antioxidants include, but are not limited to, L-ascorbic acid and its salts.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

(Ink cartridge structure example)
Next, an embodiment of an ink cartridge according to the present invention will be described with reference to the drawings.

  1 is an external perspective view of an ink cartridge according to the present invention, FIG. 2 is an exploded perspective view of the ink cartridge shown in FIG. 1 viewed from the front side, and FIG. 3 is a view of the ink cartridge shown in FIG. 4 is an exploded perspective view, FIG. 4 is a schematic view of the inside of the container body viewed from the front side, FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4, and FIG. FIG. 7 is a conceptual diagram of the atmosphere opening channel, FIG. 8 is an enlarged sectional view of the communication port on the atmosphere inflow side, and FIG. 9 is an enlarged sectional view showing a modification of the communication port on the atmosphere inflow side.

  The ink cartridge 100 according to the present embodiment is a liquid container that is mounted on a cartridge mounting unit on a carriage on which a print head that is a liquid ejecting unit is mounted in an ink jet printer (not shown).

  As shown in FIGS. 1 to 3, the ink cartridge 100 is connected to an ink chamber (liquid storage portion) 23 that is provided in the container body 21 and stores ink (liquid), and a print head on the cartridge mounting portion side. An ink supply unit (liquid supply unit) 25, an ink guide path 27 for guiding the ink stored in the ink chamber 23 to the ink supply unit 25, and the open air to the outside as the ink in the ink chamber 23 is consumed. An air release channel 102 that introduces the atmosphere into the ink chamber 23 from the hole 29 and a plurality of air chambers 31 a and 31 b that are provided in the middle of the air release channel 102 and can store ink that has entered the atmosphere release channel 102. , 31c, and an open air type ink cartridge.

  Further, the air release channel 102 of the present embodiment includes a gas / liquid separation unit 33 provided with a ventilation film (gas / liquid separation membrane) 33a provided between the air chamber 31c and the atmosphere release hole 29, and a gas / liquid separation. And a snake path 35 which is a communicating path portion formed in a meandering state between the portion 33 and the atmosphere opening hole 29. Therefore, the air opening flow path 102 causes the ink that has passed through the air opening hole 29, the snake path 35, the gas-liquid separation unit 33, and the air chambers 31a, 31b, and 31c in order as ink is consumed in the ink chamber 23 to the ink. Introduce into chamber 23.

  As shown in FIGS. 2 and 3, films (sealing members) 39a and 39b are attached to the front and back of the integrally formed container body 21 in close contact with the partition walls 37a, 37b, 37c, 37d, etc. The films 39a and 39b block the front and back open portions of the container body 21 to partition the ink chamber 23, the air chambers 31a, 31b and 31c, the ink guide path 27, and the like. Further, a lid member 41 is further attached to the surface of the container body 21 sealed with the film 39a.

  The ink supply part 25 formed in a cylindrical shape has a valve body 43 provided therein and is closed by a supply lid 45 having a supply opening 45a.

  The valve body 43 is biased toward the supply lid 45 by the coil spring 47, thereby closing the supply opening 45a. The supply lid 45 has a supply opening 45 a sealed with a sealing film 49.

  The ink cartridge 100 according to the present embodiment includes pressure adjusting means including a pressure receiving plate receiving portion 61, a coil spring 63, and a pressure receiving plate 65, and a lever 51 for attaching / detaching the ink cartridge 100 to / from the cartridge mounting portion on the carriage. And a circuit board 53 for writing ink consumption and the like, and a peelable sealing film 55 for closing the air opening hole 29. A plurality of electrode terminals 53a are formed on the circuit board 53, and when these electrode terminals 53a come into contact with electrode members (not shown) provided in the printer, the ink cartridge 100 is electrically connected to the ink jet printer. Connected. The circuit board 53 is connected to a sensor unit (not shown) that detects an ink end installed in the ink cartridge 100, and notifies the printer main body of an ink end signal based on the presence or absence of contact between the sensor unit and the ink. .

  For example, when ink is liable to bubble, a sensor unit that detects the presence or absence of ink causes malfunction due to the bubble. The foaming property of the ink by the ink cartridge of the present invention has an effect of reducing such malfunction of the sensor unit because the height of the foam after 5 minutes at 25 ° C. is 50 mm or less based on JISK3362.

  When the atmosphere open flow path 102 formed in the container main body 21 shown in FIGS. 2 and 3 is schematically shown, it becomes as shown in FIGS.

  That is, the communication port 71 of the ink chamber 23 communicates with the communication port 75 of the communication channel 73 provided on the surface side via the communication channel 72 provided on the back side of the container body 21, and the communication channel 73 is connected to the communication port 73. 77 to the air chamber 31a.

  The air chamber 31 a communicates with the back side air chamber 31 b through the communication port 79, and the air chamber 31 b communicates with the surface side communication channel 83 through the communication port 81.

  The communication channel 83 communicates with the back side air chamber 31 c through the communication port 85, and the air chamber 31 c communicates with the surface side communication channel 89 through the communication port 87.

  The communication channel 89 communicates with the back-side communication channel 90 through the communication port 91, and the communication channel 90 communicates with the back-side gas-liquid separator 33 through the surface-side communication channel 91.

  And the gas-liquid separation part 33 provided with the ventilation | gas_flowing film 33a leads to the snake way 35, and becomes the air release hole 29 in the terminal, and is air-released.

  Such an atmosphere open channel 102 is more conceptually represented as shown in FIG. Here, for example, the communication port 79 (same as the communication ports 81 and 87) on the air inflow side of the air chamber 31a (same as the air chambers 31b and 31c) is formed from an inner wall surface 93 of the air chamber 31a as shown in FIG. An opening is formed in the tip end surface 95a of the protruding cylindrical protrusion 95. The protrusion 95 is not limited to a cylindrical shape, and may be formed in a polygonal column shape, a conical shape, or a polygonal pyramid shape as long as the tip surface is appropriately separated from the inner wall surface.

  According to the ink cartridge 100 having such a configuration, even if the ink in the ink chamber 23 passes through the communication port 77 on the air outflow side of the air chamber 31a and accumulates in the air chamber 31a, the ink enters the communication port 79 on the air inflow side. The time to reach is delayed by the height of the protrusion 95.

  That is, in the container leaving state where the communication port 79 on the air inflow side is oriented in the vertical direction, the ink that has flowed into the air chamber 31 a is accumulated up to the height h of the protrusion 95, and then is opened to the tip surface 95 a of the protrusion 95. It flows out from the communication port 79 on the inflow side. Thereby, the time until the ink flows out from the communication port 79 on the air inflow side to the next air chamber 31b is delayed.

  In addition, the conventional ink cartridge communication port 7 is easily broken due to an impact caused by dropping of the container body or attachment / detachment to the cartridge mounting portion, a change in posture during movement, an inertial force due to carriage operation, or an air expansion in the ink chamber. Unlike the formed meniscus (see FIG. 10), the ink cartridge 100 of the present embodiment can stably prevent liquid leakage from the communication port 79 on the air inflow side in the air chamber 31a.

  Furthermore, in the atmosphere open flow path 102 according to the ink cartridge 100 of the present embodiment, a plurality of air chambers 31a, 31b, 31c are provided, and the adjacent air chambers communicate with each other through the communication ports 79, 80 and the communication flow path 83. It is communicated by.

  Therefore, even in a limited space in the container main body 21, it is easy to secure the volume of the entire air chamber for storing ink.

  Further, the communication ports 79, 81, 87 on the air inflow side of the air chambers 31a, 31b, 31c are opened at the front end surfaces of the protrusions protruding from the inner wall surfaces of the air chambers (see, for example, the protrusion 95 in FIG. 8). Has been.

  Therefore, it is possible to further delay the time until the ink flows out from the communication port 87 on the most air inflow side.

  Furthermore, by opening the respective communication ports 79, 81, 87 in different directions as appropriate, it is possible to cope with various container leaving postures and reliably prevent ink leakage from the air chambers 31a, 31b, 31c. be able to.

  For example, in the case of a thin cartridge in which the container main body 21 is formed in a flat and substantially rectangular parallelepiped like the ink cartridge 100 of the present embodiment, the direction most likely to be placed by the user is the wide surface of the container main body 21. Since the posture is one of the front and back surfaces (that is, the posture in which the thickness direction is the vertical direction), the protrusion 95 inside the container body 21 faces the vertical direction. Therefore, by causing the protrusions 95 to protrude in the thickness direction of the container body 21, the ink trap rate can be increased.

  Furthermore, by projecting the protrusions 95 of the air chambers 31a, 31b, and 31c in alternate directions, either one of the widest front and back surfaces of the ink cartridge 100 is placed downward. The protrusions 95 in the air chambers 31a, 31b, and 31c protrude from the accumulated ink surface, and the communication ports 79, 85, and 87 of any one of the front end surfaces 95a are disposed on the ink surface. As a result, the ink trap rate can be uniformly increased (see FIG. 5).

  Further, in the atmosphere open channel 102 of the present embodiment, the air outlet 31 side communication port 77 (same as the communication ports 80 and 85) of the air chamber 31a (same as the air chambers 31b and 31c) is connected to the air chamber 31a (31b). , 31c) is opened on the same plane as the inner wall surface 97 (see FIG. 8).

  Therefore, the air inflow side communication port 79 (81, 87) in the air chamber 31a (31b, 31c) has a trap structure that makes it difficult for ink to flow out, whereas the air outflow side communication port 77 (80, 85). ) Has a structure in which ink can easily enter, and the ink accumulated in the air chamber 31a (31b, 31c) passes through the communication port 77 (80, 85) on the air outflow side where it can easily enter, and then returns to the ink chamber 23 again. It becomes easy to collect.

  In the ink cartridge 100 of the present embodiment, as shown in FIGS. 3 and 6, air is allowed to pass through the atmosphere opening flow path 102 on the atmosphere opening hole 29 side from the air chamber 31 c and ink is allowed to pass. A gas-liquid separation part 33 provided with a non-venting air-permeable film 33a is provided, and a snake path 35 which is a communicating passage part formed in a meandering manner in the middle of the air release channel 102 on the air release hole 29 side from the gas-liquid separation part 33. Is provided.

  Therefore, even if ink leaks from the air chamber 31c, the ventilation film 33a can reliably prevent leakage of the ink to the outside of the cartridge. In addition, the snake path 35 can be expected to delay the leakage of ink to the outside of the ink cartridge, and the air flow between the ventilation film 33a and the air release hole 29 is reduced, thereby reducing ink evaporation. can do.

  In addition, the leakage of the liquid from the air chamber is delayed, and the liquid-liquid separation membrane reliably prevents the liquid from leaking to the outside, so that the liquid enters the communication path and the dynamic pressure on the liquid supply section changes significantly. I will not let you.

  Furthermore, since leakage of ink from each air chamber 31a (31b, 31c) is stably prevented as described above, the ventilation film 33a gains time until the ventilation performance is deteriorated by contacting the ink. And stable ventilation performance can be maintained over a long period of time. In addition, ink leakage from each air chamber 31a (31b, 31c) is stably prevented, and leakage of ink to the outside of the cartridge is reliably prevented by the ventilation film 33a. Does not significantly change the dynamic pressure applied to the ink supply unit 25.

  Further, when the container body 21 is integrally formed by the upper and lower molds as in the ink cartridge 100 of the present embodiment, the axis of the protruding direction of the protrusion 95 is parallel to the mold opening direction of the upper and lower molds. As a result, the protrusion 95 having the same orthogonal cross-sectional shape at any position in the axial direction has the same axis opening direction as that of the upper mold and the lower mold. Therefore, when the container body 21 is integrally formed, a slide mold for forming the protrusions 95 is not required, and the moldability is improved, so that the container body 21 can be easily manufactured.

  Further, as shown in FIG. 8, in the ink cartridge 100 of the present embodiment, the edge portion 95c where the tip end surface 95a and the side surface 95b of the protrusion 95 intersect has a corner in cross section. That is, R or chamfering is not performed on the edge portion 95c where the tip surface 95a and the side surface 95b of the protrusion 95 intersect.

  Therefore, in the container leaving state where the protrusion 95 is directed in the vertical direction, the ink that scoops up the side surface 95b of the protrusion 95 by surface tension prevents the protrusion 95 from wrapping around the tip surface 95a by the corner of the edge portion 95c. Is done. Therefore, even if ink accumulates in the air chamber 31a, the ink does not enter the communication port 79 on the air inflow side until the protrusion height h of the protrusion 95.

  Furthermore, as shown in FIG. 9, the protrusion height h of the protrusion 95 can be set to a height that leaves a gap t at which no meniscus due to ink is formed between the opposing inner wall surface (film 39a or inner wall surface 97).

  In this case, even if the ink accumulated in the air chamber 31a comes into contact with the front end surface 95a of the protrusion 95 due to an impact caused by the drop of the container body 21 or attachment / detachment to the cartridge mounting portion, a posture change during movement, an inertial force due to carriage operation, or the like. Ink does not form a meniscus between the ink 39 and the film 39a which is the opposite inner wall surface by capillary attraction, and it is difficult for the ink to enter the communication port 79 opened in the front end surface 95a.

  Therefore, according to the ink cartridge 100, the ink stored in the air chambers 31a, 31b, and 31c is strong against the impact, inertial force, and internal / external pressure change on the container body 21, and the communication ports 79 and 81 on the air inflow side are stored. , 87 can provide a good ink cartridge capable of delaying the time to flow out.

  As a result, according to the ink jet printer using the ink cartridge 100 of this embodiment, the dynamic pressure change with respect to the ink supply unit 25 is suppressed, and high quality printing can be maintained.

(Ink Example)
In the following production examples, examples and comparative examples, “parts” and “%” are “parts by weight” and “% by weight” unless otherwise specified.

Ink Example 1
(1) Production of pigment dispersion In a reaction vessel, 25 parts by weight of methyl ethyl ketone, 0.04 part by weight of a polymerization chain transfer agent (2-mercaptoethanol), methacrylic acid (Mitsubishi Gas Chemical Co., Ltd., trade name GE-110 (MAA) )) 15 parts by weight, 15 parts by weight of styrene macromer (Toa Gosei Co., Ltd., trade name AS-6S), 30 parts by weight of 2-ethylhexyl methacrylate (Mitsubishi Rayon Co., Ltd., trade name Acryester EH), styrene monomer (Nippon Steel Chemical Co., Ltd.) 10 parts by weight of 25 parts by weight of a company, trade name styrene monomer) and 15 parts by weight of methoxypolyethylene glycol monomethacrylate were mixed together, and nitrogen gas substitution was sufficiently performed to obtain a mixed solution.

  On the other hand, the remaining 90% by weight of each monomer was charged into a dropping funnel, and then 0.27 parts by weight of a polymerization chain transfer agent (2-mercaptoethanol), 60 parts by weight of methyl ethyl ketone and 2,2′-azobis (2, 4-Dimethylvaleronitrile) 1.2 parts by weight was added and mixed, and nitrogen gas substitution was sufficiently performed to obtain a mixed solution.

  Under a nitrogen atmosphere, the mixed solution in the reaction vessel was heated to 75 ° C. while stirring, and the mixed solution in the dropping funnel was gradually dropped into the reaction vessel over 3 hours. After completion of the dropping, the temperature of the mixed solution was maintained at 75 ° C. for 2 hours, and then a solution in which 0.3 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in 5 parts by weight of methyl ethyl ketone was prepared. In addition to the mixed solution, the mixture was further aged at 75 ° C. for 2 hours and 85 ° C. for 2 hours to obtain a polymer solution.

  A portion of the resulting polymer solution was isolated by drying at 105 ° C. under reduced pressure for 2 hours and removing the solvent. The weight average molecular weight determined by gel permeation chromatography using polystyrene as a standard substance and 60 mmol / L phosphoric acid and 50 mmol / L lithium bromide-containing dimethylformamide as a solvent was 121,000.

  30 parts by weight of the copolymer obtained by drying the obtained copolymer solution under reduced pressure was dissolved in 75 parts by weight of methyl ethyl ketone, and 220 parts by weight of ion-exchanged water and sodium hydroxide (30% aqueous solution) were placed therein. A certain amount (in which the degree of neutralization of the salt-forming group is 65%) is added to neutralize a part of the copolymer, and C.I. I. 70 parts by weight of Pigment Violet 19 was added, and the mixture was kneaded with a bead mill and dispersed.

  After adding 240 parts by weight of ion-exchanged water to the obtained dispersion and stirring, methyl ethyl ketone was removed at 60 ° C. under reduced pressure, and a part of the water was further removed.

  By mixing and stirring 40 parts of an aqueous dispersion of the obtained pigment-containing polymer particles and 1 part of dibutyl sebacate which is a water-insoluble organic compound, dibutyl sebacate is contained in the polymer particles and filtered through a membrane filter. A pigment dispersion containing water-insoluble polymer particles and a water-insoluble organic compound having a solid content concentration of 20% was obtained.

(2) Production of ink composition 30 parts by weight of the pigment dispersion (solid content concentration 20% by weight) obtained in Example 1 (1), 4 parts by weight of triethylene glycol monobutyl ether, 2 parts by weight of 1,2-hexanediol Part, 1 part by weight of Olfin E1010 (manufactured by Nissin Chemical Industry Chemical Co., Ltd.), 15 parts by weight of glycerin, 3 parts by weight of trimethylolpropane, and 45 parts by weight of ion-exchanged water were mixed.

  The obtained mixed liquid was filtered through a 10 μm membrane filter to obtain an ink composition of Example 1.

(3) Manufacture of Ink Cartridge The ink prepared in Example 1 (2) was injected into the cartridge 100 described in the “Ink Cartridge Structure Example” to obtain the ink cartridge of Example 1.

Ink Example 2
(1) Production of pigment dispersion In Example 2, C.I. I. In place of Pigment Violet 19, C.I. I. Pigment having a solid content concentration of 20% by weight was treated in the same manner as in Example 1 (1) except that CI Pigment Blue 15: 4 was used and dibutyl sebacate, which is a water-insoluble organic compound, was not used. A pigment dispersion contained in insoluble polymer particles was obtained.

(2) Manufacture of ink composition The composition and method were the same as in Example 1 (2) except that the pigment dispersion (solid content concentration 20% by weight) obtained in Example 2 (1) was used. Ink composition 2 was obtained.

(3) Manufacture of Ink Cartridge The ink prepared in Example 2 (2) was injected into the cartridge 100 described in the “Structure Example of Ink Cartridge” to obtain an ink cartridge of Example 2.

(Ink comparison example)
Comparative Example 1
(1) Production of pigment dispersion C.I. I. Pigment Violet 19 and a styrene-acrylic resin (John Crill 61J, manufactured by Johnson Polymer Co., Ltd.) as a dispersant are mixed, and glass beads (diameter 1.7 mm, 1. 5 hours (weight)) and dispersed for 2 hours. After dispersion, the glass beads were removed, another solvent and water were added, stirred at room temperature for 30 minutes, and filtered through an 8 μm membrane filter to obtain a pigment dispersion having a solid content concentration of 20%.

(2) Production of Ink Composition 30 parts by weight of the pigment dispersion (solid content concentration 20% by weight) obtained in Comparative Example 1 (1), 4 parts by weight of triethylene glycol monobutyl ether, 2 parts by weight of 1,2-hexanediol Part, 1 part by weight of Olfin E1010 (manufactured by Nissin Chemical Industry Chemical Co., Ltd.), 15 parts by weight of glycerin, 3 parts by weight of trimethylolpropane, and 45 parts by weight of ion-exchanged water were mixed.

  The obtained mixed liquid was filtered through a 10 μm membrane filter to obtain an ink composition of Comparative Example 1.

(3) Manufacture of Ink Cartridge The ink cartridge of Comparative Example 1 was obtained by injecting the ink prepared in Comparative Example 1 (2) into the cartridge 100 described in the “Structure Example of Ink Cartridge”.

Comparative Example 2
(1) Production of Pigment Dispersion In Comparative Example 2, the same pigment dispersion as in Comparative Example 1 (1) was used.

(2) Production of ink composition 30 parts by weight of the pigment dispersion (solid content concentration 20% by weight) obtained in Comparative Example 1 (1), 1 part of dibutyl sebacate which is a water-insoluble organic compound, triethylene glycol monobutyl ether 4 parts by weight, 1,2-hexanediol 2 parts by weight, Olphine E1010 (manufactured by Nissin Chemical Industry Chemical Co., Ltd.) 1 part by weight, glycerin 15 parts by weight, trimethylolpropane 3 parts by weight, and ion-exchanged water 44 parts by weight Mixed.

  The obtained mixed liquid was filtered through a 10 μm membrane filter to obtain an ink composition of Comparative Example 2.

(3) Manufacture of Ink Cartridge The ink cartridge of Comparative Example 2 was obtained by injecting the ink prepared in Comparative Example 2 (2) into the cartridge 100 described in the “Structure Example of Ink Cartridge”.

  Next, for each ink composition or ink cartridge of Examples and Comparative Examples: 1. Evaluation of foamability at 25 ° C. based on JISK3362. 2. Print stability evaluation; Storage stability evaluation was performed.

(1) Foaming property evaluation based on JISK3362 About each ink composition of an Example and a comparative example, foaming property evaluation was performed by the following procedures.

  In an environment of 25 ° C., 200 ml of ink was allowed to flow down from a height of 900 mm to a graduation tube containing 50 ml of ink for 30 seconds, and the height of bubbles generated at that time was measured. The evaluation results are shown in Table 1.

(2) Evaluation of printing stability The printing stability of each ink cartridge of Examples and Comparative Examples was evaluated according to the following procedure.

  After dropping to the ground 5 times from a height of 1 m and letting it stand for a day, set it on the inkjet printer PX-A720 (Seiko Epson Corporation) and print 20 solid print patterns continuously. The printing stability was evaluated. The evaluation results are shown in Table 1.

A: Through 20 continuous prints, there is no print omission or unevenness.
B: Printing failure or unevenness occurs on at least 1 to 4 of 20 continuous prints.
C: Out of 20 continuous prints, at least 5 or more prints are missing or uneven.
According to the above evaluation method, when bubbles or ink leaks from the air chamber of the ink cartridge due to the impact of natural fall and adheres to the ventilation film 33a, it is presumed that the ejection performance becomes unstable due to the deterioration of the ventilation performance.

(3) Storage Stability Evaluation The storage stability of each ink cartridge of Examples and Comparative Examples was evaluated according to the following procedure.

  Each ink cartridge was left for 2 weeks in an environment of 60 ° C. Observe the presence or absence of foreign matter (floating matter or sediment) after standing, and for those that do not generate foreign matter, investigate further changes in physical properties (viscosity, surface tension, pH, particle size) and based on the following criteria: Storage stability was evaluated. The evaluation results are shown in Table 1.

A: No foreign matter is generated, and there is no change in physical properties.
B: No foreign matter is generated, but the physical properties slightly change.
C: Foreign matter is generated or the physical properties are remarkably changed.

FIG. 1 is an external perspective view of a liquid container according to the present invention. The disassembled perspective view which looked at the liquid container shown in FIG. 1 from the surface side. The disassembled perspective view which looked at the liquid container shown in FIG. 1 from the back side. The schematic diagram which looked at the inside of a container main body from the surface side. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. The schematic diagram which looked at the inside of a container main body from the back side. The conceptual diagram of an open air flow path. The expanded sectional view of the communicating port by the side of the air inflow. The expanded sectional view showing the modification of the communicating port by the side of the air inflow. The expanded sectional view of the communicating port by the side of the atmosphere inflow in the conventional liquid container.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 21 ... Container main body, 23 ... Ink chamber (liquid storage part), 25 ... Ink supply part (liquid supply part), 29 ... Air release hole, 31a, 31b, 31c ... Air chamber, 33a ... Ventilation film (gas-liquid separation membrane) ), 35... Snake way (communication passage portion formed in a meandering state), 77, 80, 85... Communication port on the air outflow side of the air chamber, 79, 81, 87. 97... Inner wall surface of air chamber, 95... Projection, 95 a... Tip end surface, 95 b.

Claims (9)

Ink accommodated in the container, an ink storage part provided in the container for storing ink, an ink supply part communicating with the ink storage part, and opened to the outside as the ink in the ink storage part is consumed An ink cartridge comprising an air release channel for introducing air from the air release hole into the ink storage portion, and an air chamber provided in the middle of the air release channel and capable of storing ink that has entered the air release channel. Because
The communication port on the air inflow side of the air chamber is opened at the front end surface of the protrusion protruding from the inner wall surface of the air chamber,
An ink cartridge for ink-jet recording, wherein the foaming property of the ink contained in the container is 50 mm or less after 5 minutes at 25 ° C. based on JISK3362.   The ink cartridge for inkjet recording according to claim 1, wherein the ink contained in the container contains at least water, a colorant, and water-insoluble polymer particles.   The ink cartridge for inkjet recording according to claim 1 or 2, wherein the ink contained in the container contains at least water, a colorant, water-insoluble polymer particles, and a water-insoluble organic compound.   The gas-liquid separation membrane which allows passage of gas and does not allow passage of liquid is provided in the middle of the atmosphere opening flow path on the atmosphere opening hole side from the air chamber. The ink cartridge for ink-jet recording according to any one of the above.   The communicating path part formed in the meandering state is provided in the middle of the said air release flow path by the side of an air release hole from the said gas-liquid separation film | membrane, The Claim 1 characterized by the above-mentioned. Ink cartridge for ink jet recording.   The ink cartridge for inkjet recording according to any one of claims 1 to 5, wherein a plurality of the air chambers are provided, and adjacent air chambers communicate with each other.   The ink cartridge for inkjet recording according to any one of claims 1 to 6, wherein a communication port on the air outflow side of the air chamber is opened on the same plane as an inner wall surface of the air chamber. .   The water-insoluble polymer particles are water-insoluble polymer particles obtained by copolymerizing a monomer mixture containing a salt-forming group-containing monomer and a macromer and / or a hydrophobic monomer. The ink cartridge for inkjet recording according to one item.   The water-insoluble organic compound has two or more ester or ether bonds in the molecule, and / or one or more ester or ether bonds in the molecule, a carboxy group, a sulfonic acid group, 9. An ester or ether compound having at least one functional group selected from the group consisting of a phosphoric acid residue, a carbonyl group, an epoxy group and a hydroxyl group. 2. An ink cartridge for ink jet recording described in 1.

Images