JP2008307773A - Inkjet recording apparatus and ink cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus in which EPDM (ethylene-propylene-diene rubber) having improved ink resistance is used and which is excellent in long-term stability and to provide an ink cartridge. <P>SOLUTION: The inkjet recording apparatus has a recording head having an ink discharge plane, on which a plurality of ink discharge ports for discharging ink are arranged, and is used for printing an image by using the recording head. The EPDM is used in at least one selected from portions of the inkjet recording apparatus to be in contact with the ink, portions thereof to which the ink is stuck, and rubber-based components thereof. The EPDM to be used contains butyl halide. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and an ink cartridge having improved ink resistance.

  Conventionally, compared to gravure printing and flexographic printing methods, the plate making process is not required, so the cost of small lot printing can be reduced, printing on various types and sizes of recording media, silver 2. Description of the Related Art Inkjet recording apparatuses are increasingly used for the reason that images comparable to salt photographs can be provided. An ink jet recording apparatus using an ink jet system discharges ink as fine droplets from a discharge port of a head toward a recording medium such as paper while moving the head on the recording medium, and allows the ink to permeate the recording medium. An image is recorded on a recording medium by fixing.

  In general, water-based ink-jet ink containing water as the main solvent is recorded on special paper with ink absorbability, but phase change ink-jet method using solid wax ink at room temperature, ink mainly composed of fast-drying organic solvent Ink jets other than water-based ink jet systems, such as a solvent-based ink jet system that uses a UV light, and an actinic ray curable ink jet system that is crosslinked by irradiation with active energy rays (radiation) such as ultraviolet rays (UV light) after recording, have been put into practical use.

  Among them, the ultraviolet curable ink jet method has been attracting attention in recent years because it has a relatively low odor compared to the solvent ink jet method, can be quickly dried, and can be recorded on a recording medium having no ink absorption ability. An actinic ray curable ink jet technology is disclosed.

  Actinic ray curable ink jet inks that use radically polymerizable compounds represented by (meth) acrylates have been put into practical use, but recently, they have adhesion to recording media, low odor, and polymerization inhibition by oxygen. For reasons such as few, actinic ray curable ink jet ink using a cationically polymerizable compound and an ink jet recording apparatus using the ink have been proposed (for example, see Patent Documents 1 and 2).

  On the other hand, an ink jet recording apparatus used for printing ink jet ink mainly includes an ink cartridge (ink tank) for storing and supplying ink, a filter box for removing foreign matter in the ink and preventing clogging, Ink-jet recording head, maintenance unit that cleans nozzle surface and nozzles are connected to supply ink to prevent ejection defects and nozzle clogging caused by ink-jet ink adhering to the nozzle surface of the recording head. In order to prevent ink leakage or the like, an ink supply path (ink tube), a joint for connecting the ink supply path and each component, or a leakage of ink in each component is used. .

  These components often use metals such as stainless steel and aluminum from the viewpoint of durability against ink. On the other hand, a rubber member is often used as a part that requires flexibility such as a cleaning blade, an ink supply path, an ink cartridge connection portion, a packing, an O-ring, and the like constituting the maintenance unit.

  The rubber member used for these components is required to have high durability against ink, low water vapor and air permeability, and excellent flexibility and rubber elasticity.

As one of rubber members satisfying these demands, a method of applying ethylene-propylene-diene rubber (EPDM) has been proposed. For example, a method of using EPDM as an O-ring used for a valve seat in an air vent valve of an ink jet recording apparatus for automatically removing air mixed in an ink flow path is disclosed (for example, see Patent Document 3). . Also disclosed is an ink tube for an ink jet printer formed of a thermoplastic elastomer composition in which a rubber component containing EPDM rubber is finely dispersed by dynamic crosslinking in an olefinic thermoplastic resin (see, for example, Patent Document 4). .)
JP 2005-290246 A JP 2004-34543 A JP 11-48501 A JP 2005-138506 A

  EPDM having low water vapor and air permeability is widely used for packing, maintenance unit cleaning blades, and the like in addition to the O-rings and ink tubes (ink supply paths) as described above.

  When EPDM is applied to each of such constituent members, a softening agent is added for the purpose of imparting flexibility and reducing rubber hardness. As the softening agent, for example, paraffinic and naphthenic oils, plasticizers represented by phosphate esters and phthalate esters, and the like are used.

  However, EPDM has a defect in oil resistance, and is in contact with the ink in an ink jet recording apparatus using an active energy ray curable ink jet ink containing a non-aqueous active energy ray curable compound, or in a portion where the ink adheres. When EPDM containing such a softening agent is applied, the polymerizable monomer in the active energy ray-curable inkjet ink causes the softening agent to be eluted from the EPDM, resulting in swelling and dissolution of the EPDM. It was found to cause deterioration and ink leakage. In particular, when an active energy ray-curable inkjet ink using a cationic polymerizable compound is used as the active energy ray polymerization compound, it has been found that the deterioration becomes remarkable, and an immediate improvement is desired.

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide an ink jet recording apparatus and an ink cartridge that improve the ink resistance of EPDM and have excellent long-term stability.

  The above object of the present invention is achieved by the following configurations.

  1. In a recording head having an ink ejection surface provided with a plurality of ink ejection ports for ejecting ink, and an ink jet recording apparatus for printing an image by the recording head, a portion in contact with the ink, a portion to which the ink adheres, and a rubber system An ink jet recording apparatus, wherein at least one selected from component parts uses ethylene-propylene-diene rubber (EPDM), and the ethylene-propylene-diene rubber (EPDM) contains butyl halide.

  2. 2. The inkjet recording apparatus according to 1 above, wherein a content of the butyl halide with respect to a total mass of the ethylene-propylene-diene rubber (EPDM) is 0.01% by mass or more and 0.5% by mass or less. .

  3. 3. The ink jet recording apparatus according to item 1 or 2, wherein the butyl halide is butyl chloride.

  4). 4. The inkjet recording apparatus according to any one of 1 to 3, wherein the ethylene-propylene-diene rubber (EPDM) containing the halogenated butyl is used in a maintenance unit for cleaning the recording head. .

  5. 5. The ink jet recording apparatus according to any one of 1 to 4, wherein ethylene-propylene-diene rubber (EPDM) containing the halogenated butyl is used in an ink cartridge that supplies the ink.

  6). Any one of 1 to 5 above, wherein the ink is an active energy ray-curable inkjet ink containing an active energy ray-curable compound that is cured by irradiation with active energy rays, and the active energy rays are ultraviolet rays. 2. An ink jet recording apparatus according to item 1.

  7. Any one of 1 to 6 above, wherein the ink is an ultraviolet curable inkjet ink containing an ultraviolet curable compound that is cured by irradiation of ultraviolet rays, and the ultraviolet curable compound is a cationic polymerizable compound. 2. An ink jet recording apparatus according to 1.

  8). An ink cartridge, wherein at least one of a portion in contact with ink or a portion to which ink is attached is made of ethylene-propylene-diene rubber (EPDM) containing butyl halide.

  According to the present invention, it is possible to provide an ink jet recording apparatus and an ink cartridge which have improved ink resistance of EPDM and are excellent in long-term stability.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventors have found that a recording head having an ink ejection surface provided with a plurality of ink ejection ports for ejecting ink, and an inkjet recording apparatus that prints an image using the recording head. At least one selected from a portion in contact with the ink, a portion to which the ink adheres, and a rubber-based component uses ethylene-propylene-diene rubber (EPDM), and the ethylene-propylene-diene rubber (EPDM) is butyl halide. It has been found that an ink jet recording apparatus and an ink cartridge having improved long-term stability can be realized by improving the ink resistance of EPDM with an ink jet recording apparatus characterized by containing the above.

  In general EPDM, a copolymer of ethylene and propylene is copolymerized with a non-conjugated diene monomer as the third component, and sulfur crosslinking (vulcanization) is made possible by copolymerizing the diene monomer. Is. As described above, when rubber parts are applied to parts constituting the ink jet recording apparatus, such as ink supply tubes, packing, O-rings, suction caps, cleaning blades, etc., it is necessary to reduce the rubber hardness before applying. In EPDM, a softening agent is added as a means for reducing rubber hardness.

  In general, the characteristics of EPDM are excellent in ozone resistance, heat resistance, weather resistance, chemical resistance, resilience, and the like, but also have the disadvantage of extremely low oil resistance. When EPDM having such characteristics is applied to an ink jet recording apparatus using water-based ink, no particular problem occurs, but an active energy ray-curable ink jet containing an active energy ray-curable compound that is a non-water-based ink-jet ink. In the system using ink, as described above, the softening agent is extracted to cause swelling and dissolution. This tendency was found to be particularly noticeable when a cationic polymerization type active energy ray curable inkjet ink using a cationic polymerizable compound such as an oxetane compound, an epoxy compound, or a vinyl ether compound was used. .

  As a result of repeated studies on means for preventing elution of the softening agent, the present inventor can prevent elution of the softening agent by adding butyl halide to EPDM, and ink jet recording excellent in ink resistance. A component of the apparatus could be obtained. Further, the constituent member according to the present invention can be obtained at a lower cost as compared with fluorine rubber, silicone rubber and the like using a fluorine-based compound conventionally known as a highly durable member.

  Details of the present invention will be described below.

[Ethylene-propylene-diene rubber (EPDM)]
As described above, the ethylene-propylene-diene rubber (EPDM) applied to the present invention can be obtained by copolymerizing a non-conjugated diene monomer as a third component with a copolymer of ethylene and propylene. Is made possible by sulfur crosslinking (vulcanization). Ethylene-propylene (EPM) is a copolymer of ethylene and propylene and requires a resin crosslinking agent, a peroxide crosslinking agent, etc. as a crosslinking agent. In EPDM, a non-conjugated diene monomer is used as a third component. Can be applied to the sulfur crosslinking method (vulcanization) used in conventional rubber production, and is used in a wide range of fields.

  In the present invention, butyl halide is added to EPDM. By containing the butyl halide according to the present invention, it is possible to prevent elution of the softening agent, which was a drawback of EPDM, and particularly in a system using a cationic polymerization type active energy ray-curable inkjet ink. Demonstrate the effect. The butyl halide according to the present invention also has an action as a softening agent.

  Examples of the butyl halide according to the present invention include butyl chloride, butyl bromide, butyl iodide, and the like, but butyl chloride is preferred from the viewpoint of further achieving the object effects of the present invention.

  In the present invention, the addition amount of butyl halide with respect to EPDM is preferably 0.01% by mass or more and 0.5% by mass or less, more preferably 0. 1% by mass or more and 0.3% or less.

  The EPDM and butyl halide according to the present invention can be obtained according to a conventionally known synthesis method. EPDM can also be obtained as a commercial product. For example, Nordel (trade name) manufactured by DuPont Performance Elastomers, JSR EP (trade name) manufactured by JSR, Esprene (trade name) manufactured by Sumitomo Chemical Co., Ltd. And Buna AP (trade name) manufactured by Bayer Buna GmbH, Mitsui-EPT (trade name) manufactured by Mitsui Chemicals, Royalene (trade name) manufactured by Uniroyal Chemical, and the like.

  The method for forming each component constituting the ink jet recording apparatus of the present invention using EPDM containing butyl halide according to the present invention is not particularly limited, but a desired shape according to a method known in the art. Can be molded.

  Hereinafter, the representative process will be described.

1) Blending step This blending step blends EPDM with butyl halide according to the present invention and other compounding agents such as a vulcanizing agent, a reinforcing agent, a filler, a softening agent, an anti-aging agent and the like in a predetermined ratio. It is a process.

2) Processing step After mixing the mixture blended in the above blending step using a kneader such as a Banbury mixer, rolling and extruding with a calendar tuber etc. to form a compound, necessary using a molding machine This is a process of forming into a simple shape.

3) Vulcanization step The material molded in the above processing step is placed in a mold and heated with a press or a vulcanization can to form a rubber elastic body having a desired shape.

  As a vulcanizing agent used in the above-mentioned process, it binds between chain rubber molecules to form a three-dimensional structure, and sulfur can be mainly used.

The reinforcing agent is blended to increase the hardness, elasticity, and friction resistance of the molded product, and examples thereof include carbon black and inorganic fillers (for example, SiO ₂ and CaCO ₃ ). .

  Examples of the softener include plant softeners (eg, stearic acid, lauric acid, palm oil), mineral softeners (eg, paraffinic, naphthenic, aromatic).

[Inkjet recording device]
Next, an outline of an ink jet recording apparatus to which EPDM containing butyl halide according to the present invention is applied will be described with reference to the drawings.

  The ink jet recording apparatus of the present invention can be applied to ink jet inks having various characteristics, but among them, an active energy ray-curable ink jet ink (hereinafter, also simply referred to as ink) capable of exhibiting particularly effects. An ink jet recording apparatus using the above will be described.

  FIG. 1 is a diagram showing an example of the overall configuration of an ink jet recording apparatus applicable to the present invention.

  Reference numeral 1 denotes an ink cartridge that stores and supplies ink. In FIG. 1, for example, a configuration including a yellow ink cartridge 1Y, a magenta ink cartridge 1M, a cyan ink cartridge 1C, and a black ink cartridge 1K is shown. J is a joint connecting the ink cartridge 1 and the ink supply path.

  Reference numeral 2 denotes an ink jet recording head having nozzles for forming an image by ejecting ink droplets onto a recording material. The yellow ink jet recording head 2Y, the magenta ink jet recording head 2M, the cyan ink jet recording head 2C, and the black ink jet recording head 2K. Consists of. Reference numeral 3 denotes an active energy ray source that irradiates ink that has landed on the recording material with ultraviolet rays that are active energy rays.

  Reference numeral 4 denotes a carriage. The carriage 4 integrally mounts the ink jet recording head 2 and the energy ray source 3, and is guided by the carriage guide 5 to reciprocate as indicated by arrows WX1 and WX2. Scanning is performed to form an image on the recording material P.

  A filter box 6 includes a yellow filter box 6Y, a magenta filter box 6M, a cyan filter box 6C, and a black filter box 6K. An intermediate tank 7 includes a yellow intermediate tank 7Y, a magenta intermediate tank 7M, a cyan intermediate tank 7C, and a black intermediate tank 7K.

  Ink is sent from the ink cartridge 1 to the intermediate tank 7, and is supplied from the intermediate tank 7 to the inkjet recording head 2 through the ink supply path 8. The ink supply path 8 is composed of supply paths for yellow ink, magenta ink, cyan ink, and black ink, and each single color ink is independently recorded from the ink cartridge 1 via the ink supply path 8 for ink jet recording. Supplied to the head 2.

  A maintenance unit 10 performs a recovery process for the inkjet recording head 2 and includes a suction cap 9 for capping the inkjet recording head 2. A waste ink container 12 for storing waste ink receives and stores ink forcedly ejected from the inkjet recording head 2 during flushing.

  In the ink jet recording apparatus having the above-described configuration, the parts configured by the EPDM containing butyl halide according to the present invention are applied to a part in contact with the ink, a part to which the ink adheres, and a rubber-based component. It applies to at least one place chosen from. Specifically, it is preferably applied to a member that requires flexibility and elasticity. When the ink cartridge 1 is a needle-type ink cartridge, the rubber plug portion into which the needle is inserted, and the maintenance unit 10, In an apparatus for wiping the inkjet recording head 10 with a cloth, it is preferably applied to a roller roll, a cleaning blade, a suction cap 9 and the like for bringing the wipe and the inkjet recording head 10 into close contact with each other. Other applicable members can be used for a tube constituting the ink supply path 8, an O-ring of the joint J portion, a diaphragm member of a diaphragm pump for feeding ink, a check valve, and the like.

  In the ink jet recording apparatus of the present invention, the active energy ray-curable ink is ejected onto the recording material using the ink jet recording apparatus represented by FIG. 1 as described above, and then the active energy ray is irradiated and cured. Although an image is formed, an ink jet recording head, an active energy ray irradiation device, and a curing method using active energy ray irradiation will be described below.

  Examples of the active energy ray used for curing the active energy ray-curable ink according to the present invention include ultraviolet rays, X-rays, and electron beams. As a light source that can be used when the ink is cured by ultraviolet rays, various light sources can be used. For example, a mercury lamp, a metal halide lamp, an electrodeless lamp, an excimer laser, an ultraviolet laser, a cold cathode tube, a hot cathode tube, Black light, LED (Light Emitting Diode), etc. are mentioned. In the case of curing with an electron beam, various irradiation devices can be used, for example, a cockroft-warthin type, a bandegraph type, or a resonance transformer type, and the electron beam has an energy of 50 to 1000 eV. Preferably, it is 100 to 300 eV. In this invention, since an inexpensive apparatus can be used, it is preferable to use an ultraviolet-ray for hardening of an active energy ray hardening composition.

[Inkjet cartridge]
In the ink jet recording apparatus of the present invention, one of the features is that a member made of EPDM containing butyl halide according to the present invention is used in an ink cartridge for supplying ink.

  FIG. 2 is a schematic view showing main components of the ink cartridge.

  As shown in FIG. 2, the ink cartridge 1 is an inner bag b1 containing an active energy ray-curable ink having an ink lead-out part b2 for drawing ink on the side surface, and an ink containing container for containing the inner bag b1. It is comprised from the housing | casing c1 and the lid | cover c2 which plugs up the upper part of the housing | casing c1. In addition, a detection plate d1 is provided between the inner bag b1 and the housing c1 that is an ink storage container to detect ink consumption (ink reduction) due to printing of the inner bag b1. The side surface of the inner bag b1 containing the ink has an ink outlet portion b2, and a needle (not shown) connected to the ink supply path is inserted into the elastic member b3 to supply the ink to the ink supply path. . At this time, the elastic member is always in contact with the ink, and the durability is greatly improved by applying the EPDM containing butyl halide according to the present invention to the elastic member.

  FIG. 3 is a schematic view showing another mounting method of the ink cartridge.

  In FIG. 3, the inner bag b1 containing ink of the ink cartridge is provided with a female joint b2, and a male joint B1 is provided at a portion connected to the ink supply path. And the ink supply path part.

  The female joint b2 includes an insertion hole b21 into which the distal end B11 of the male joint B1 is inserted, an ink outlet b22 positioned at the end of the insertion hole b21, and a plug portion made of an elastic material such as rubber that closes the ink outlet b22. b23.

  The male joint B1 is provided with a packing P such as an O-ring for contacting the side surface of the ink outlet b22 of the female joint b2 and preventing ink leakage when the male joint B1 is inserted into the female joint b2. Yes. The packing P shown here is a part in contact with the ink. By applying the EPDM containing butyl halide according to the present invention to the packing P, the ink leaks without causing swelling or melting by the ink. It can be effectively prevented.

[Maintenance unit]
In the ink jet recording apparatus of the present invention, the use of the member constituted by EPDM containing butyl halide according to the present invention for the maintenance unit for cleaning the recording head can achieve the object effect of the present invention more. preferable.

  FIG. 4 is a schematic diagram illustrating an example of a maintenance unit attached to the inkjet recording apparatus.

  In FIG. 4, the maintenance unit 105 seals the ejection surface 131 in a state where the ejection port of the recording head 103 is covered, and a cap member 151 for sucking ink from the ejection port, and suction of the ink by the cap member 151 are performed. After cleaning, the cleaning unit 152 that cleans the ejection surface 131 of the recording head 103 and the ink receiving unit 153 that receives the ink ejected from the ejection port of the recording head 103 are arranged on the upper surface (the ejection surface 131 of the recording head 103). On the opposite surface). The maintenance unit 105 is provided with moving means (not shown) for moving the maintenance unit 105 in accordance with the maintenance of the recording head 103.

  The cap member 151 is formed of a material that suppresses deterioration due to the influence of ink. A plurality of cap members 151 are provided side by side, and a plurality of recording heads 103 can be sucked at a time during maintenance. Below the cap member 151, when the cap member 151 covers the discharge surface 131 of the recording head 103, a suction pump 154 that sucks the inside of the space formed by the cap member 151 and the discharge surface 131, an air communication valve ( (Not shown) are connected via a recovery pipe 154a. That is, the suction pump 154 sucks ink through the cap member 151 from the ejection port covered with the cap member 151. The ink sucked from the discharge port by the suction pump 154 is collected in the collection tank 155 through the collection pipe 154a.

  The suction pump 154 is exemplified as a means for sucking ink from the discharge port of the recording head 103. However, any device that can suck ink from the discharge port may be used, and examples thereof include a piston and a cylinder.

  The cleaning unit 152 includes a cleaning blade 152a that cleans the ejection surface 131 of the recording head 103, and an absorber 152b that absorbs ink attached to the cleaning blade 152a.

  The cleaning blade 152 a is a cleaning member that is formed of a rubber elastic body and cleans the ejection surface 131 of the recording head 103 by sliding while elastically deforming the ejection surface 131.

  In the inkjet recording apparatus of the present invention, in the maintenance unit described above, the EPDM containing butyl halide according to the present invention is applied to the cap member 151 or the cleaning blade 152a in contact with the ink, whereby the ink resistance of each member is increased. The sex can be improved dramatically.

[Active energy ray curable ink]
In the ink jet recording apparatus of the present invention, any ink can be applied, but from the viewpoint that the effects of the present invention can be more exerted, the active energy containing an active energy ray-curable compound that cures the ink upon irradiation with ultraviolet rays. It is preferably a line curable inkjet ink, and more preferably a cation polymerization type ultraviolet curable inkjet ink containing a cation polymerizable compound.

  The active energy ray curable ink-jet ink is roughly classified into a radical polymerizable curable ink containing a radical polymerizable compound and a cationic polymerizable curable ink containing a cationic polymerizable compound.

  Examples of the radical polymerizable monofunctional monomer include isoamyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, decyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol acrylate, 2-hydroxybutyl acrylate, 2 -Acryloyloxyethyl hexahydrophthalic acid, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxypropylene glycol acrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl Acrylate, -Hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, lactone modified Examples thereof include flexible acrylate and t-butylcyclohexyl acrylate.

  In the active energy ray-curable ink-jet ink according to the present invention, the polymerizable compound is preferably a cationic polymerizable compound from the viewpoint of further achieving the object effect of the present invention.

  Hereinafter, the details of the cationic polymerization type ultraviolet curable inkjet ink will be described.

  In the present invention, various known cationic polymerizable monomers can be used as the cationic polymerizable compound, and among them, compounds having an oxirane group such as JP-A-6-9714 and JP-A-2001-31892. JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and JP-A-2001-220526 include epoxy compounds, vinyl ether compounds, oxetane compounds, and the like. Can be mentioned.

  Examples of the epoxy compound include the following aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.

  Preferred as the aromatic epoxide is a di- or polyglycidyl ether produced by the reaction of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof and epichlorohydrin, such as bisphenol A or its Examples thereof include di- or polyglycidyl ethers of alkylene oxide adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or alkylene oxide adducts thereof, and novolak-type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  As the alicyclic epoxide, cyclohexene oxide or cyclopentene obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Oxide-containing compounds are preferred.

  Preferred aliphatic epoxides include di- or polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, and typical examples thereof include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or Diglycidyl ether of alkylene glycol such as diglycidyl ether of 1,6-hexanediol, polyglycidyl ether of polyhydric alcohol such as di- or triglycidyl ether of glycerin or its alkylene oxide adduct, polyethylene glycol or its alkylene oxide adduct Diglycidyl ethers of polyalkylene glycols such as diglycidyl ethers, polypropylene glycols or diglycidyl ethers of adducts thereof Tel and the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  Among these epoxides, in view of fast curability, aromatic epoxides and alicyclic epoxides are preferable, and alicyclic epoxides are particularly preferable. In the present invention, one of the epoxides may be used alone, or two or more may be used in appropriate combination.

  In the present invention, from the viewpoint of safety such as AMES and sensitization, the epoxy compound having an oxirane group is particularly preferably at least one of an epoxidized fatty acid ester and an epoxidized fatty acid glyceride.

  The epoxidized fatty acid ester and the epoxidized fatty acid glyceride are not particularly limited as long as an epoxy group is introduced into the fatty acid ester or fatty acid glyceride.

  The epoxidized fatty acid ester is produced by epoxidizing an oleic acid ester, and examples thereof include methyl epoxy stearate, butyl epoxy stearate, octyl epoxy stearate and the like. Similarly, the epoxidized fatty acid glyceride is produced by epoxidizing soybean oil, linseed oil, castor oil and the like, and epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil and the like are used.

  In the present invention, in order to further improve the curability and ejection stability, the photopolymerizable compound is 30 to 95% by mass of a compound having an oxetane ring and 5 to 70% by mass of a compound having an oxirane group. It is preferable to contain 0-40 mass% of vinyl ether compounds.

  As the oxetane compound that can be used in the present invention, any known oxetane compound as described in JP-A Nos. 2001-220526 and 2001-310937 can be used.

  Examples of vinyl ether compounds that can be used in the present invention include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, Di- or trivinyl ether compounds such as cyclohexanedimethanol divinyl ether and trimethylolpropane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexane dimethanol Bruno vinyl, n- propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether -O- propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

  Among these vinyl ether compounds, in consideration of curability, adhesion, and surface hardness, di- or trivinyl ether compounds are preferable, and divinyl ether compounds are particularly preferable. In the present invention, one of the above vinyl ether compounds may be used alone, or two or more thereof may be used in appropriate combination.

  In the ink containing the cationic polymerizable compound according to the present invention, it is preferable to contain a photoacid generator as a polymerization initiator. As the photoacid generator that can be used in the present invention, for example, a chemical amplification type photoresist or a compound used for photocationic polymerization is used (Organic Materials Research Group, “Organic Material for Imaging”, Bunshin Publishing (1993), see pages 187-192). Examples of compounds suitable for the present invention are listed below.

First, B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , CF ₃ SO ₃ ⁻ salt of aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium and phosphonium Can be mentioned.

  Specific examples of onium compounds that can be used in the present invention are shown below.

  Secondly, sulfonated substances that generate sulfonic acid can be mentioned, and specific compounds thereof are exemplified below.

  Thirdly, halides that generate hydrogen halide can also be used, and specific compounds thereof are exemplified below.

  Fourthly, an iron allene complex can be mentioned.

  The photo acid generator (photo cationic polymerization initiator) is preferably contained in a ratio of 0.2 to 20 parts by mass with respect to 100 parts by mass of the cationic polymerizable monomer. If the content of the photocationic polymerization initiator is less than 0.2 parts by mass, it is difficult to obtain a cured product, and even if the content exceeds 20 parts by mass, a further effect of improving curability cannot be expected. These cationic photopolymerization initiators can be used alone or in combination of two or more.

  The ink according to the present invention preferably contains a color material, and the color material is preferably a pigment.

  As the pigment used in the ink according to the present invention, an organic and surface-treated organic pigment is preferably used, and the content of the dispersant in the ink is preferably 35 to 65% of the pigment mass. . In the ink of the present invention, if the content of the dispersant is less than 35%, the dispersant may not be sufficiently adsorbed on the entire pigment surface, and the dispersion stability may be insufficient. If the content exceeds 65%, the pigment The dispersant that is not adsorbed on the surface may be released into the ink, causing polymerization inhibition and causing a problem. The amine value of the pigment is preferably larger than the acid value, and the difference is more preferably 1 mg / g KOH or more and less than 10 mg / g. If it is less than 1 mg / g KOH, the effect is not obtained, and if it is 10 mg / g or more, it is necessary to perform the basic treatment excessively, which not only increases the cost but also causes polymerization inhibition.

  Examples of the pigment used in the present invention include carbon pigments such as carbon black, carbon refined, and carbon nanotubes, and metal oxide pigments such as iron black, cobalt blue, zinc oxide, titanium oxide, chromium oxide, and iron oxide. Sulfide pigments such as zinc sulfide, phthalocyanine pigments, pigments composed of salts such as metal sulfates, carbonates, silicates and phosphates, and aluminum powders, bronze powders, and zinc powders Inorganic pigments such as metallic powders, nitro pigments, aniline black, nitroso pigments such as naphthol green B, azo pigments such as Bordeaux 10B, Lake Red 4R, and chromoftal red (azo lakes, insoluble azo pigments, condensed azo pigments, Including chelate azo pigments), Peacock Blue Lake and Rhodamine Ray Rake pigments such as phthalocyanine blue, polycyclic pigments (perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, quinofuranone pigments), thioindigo red Organic pigments such as selenium pigments such as Indatron Blue, quinacridone pigments, quinacridine pigments, and isoindolinone pigments can also be used.

Specific examples of pigments include
C. I Pigmen Yellow-1, 2, 3, 12, 13, 14, 16, 17, 42, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 109, 114, 120, 128, 129, 138, 150, 151, 154, 180, 185,
C. I Pigmen Orange-16, 36, 38,
C. I Pigmen Red-5, 7, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 101, 112, 122, 123, 144, 146, 168, 184, 185, 202,
C. I Pigmen Violet-19, 23,
C. I Pigmen Blue-1, 2, 3, 15: 1, 15: 2, 15: 3, 15: 4, 18, 22, 27, 29, 60,
C. I Pigmen Green-7, 36,
C. I Pigmen White-6, 18, 21,
C. I Pigmen Black-7, and the like.

  For the dispersion of the pigment, for example, a ball mill, sand mill, attritor, roll mill, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, paint shaker, or the like can be used. Further, a dispersing agent can be added when dispersing the pigment. As the dispersant, a polymer dispersant is preferably used. Examples of the polymer dispersant include Avecia's Solsperse series and Ajinomoto Fine-Techno's PB series. Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment. The dispersion medium is used using a solvent or a polymerizable compound. However, the photocurable ink of the present invention is preferably solvent-free because it is reacted and cured after printing. If the solvent remains in the cured image, the solvent resistance deteriorates and the VOC of the remaining solvent arises. Therefore, it is preferable in view of dispersibility that the dispersion medium is not a solvent but a polymerizable compound, and among them, a monomer having the lowest viscosity is selected.

  The pigment is preferably dispersed so that the average particle diameter of the pigment particles is 0.08 to 0.5 μm, and the maximum particle diameter is 0.3 to 10 μm, preferably 0.3 to 3 μm. The selection of the dispersion medium, the dispersion conditions, and the filtration conditions are appropriately set. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained. In the ink according to the present invention, the color material concentration is preferably 1 to 10% by mass of the whole ink.

  In the ink according to the present invention, various additives other than those described above can be used. For example, leveling additives, matting agents, polyester resins for adjusting film properties, polyurethane resins, vinyl resins, acrylic resins, rubber resins, and waxes can be added. In addition, for the purpose of improving storage stability, any known basic compound can be used, but representative examples include basic organic compounds such as basic alkali metal compounds, basic alkaline earth metal compounds, and amines. Compound etc. are mentioned. It is also possible to combine a radically polymerizable monomer and an initiator into a radical / cation hybrid type curable ink.

  In addition, in the ink according to the present invention containing cationic polymerizability, the water content is adjusted in the range of 0.5% by mass or more and 3.0% by mass or less in order to improve the storage stability of the ink. Is preferred. When the water content is less than 0.5% by mass, the ink storage stability decreases, and when the water content exceeds 3.0% by mass, the generation of precipitates increases, nozzle clogging and ejection stability decrease.

  In the ink according to the present invention, when used for inkjet image formation, the viscosity at 25 ° C. is preferably 7 to 50 mPa · s.

〔recoding media〕
In the present invention, various recording media can be used as a recording medium used when forming an image with the ink according to the present invention by the ink jet printer according to the present invention, but the characteristics of the ink according to the present invention are fully exhibited. From the viewpoint of being capable of being recorded, it is preferable that the recording medium has substantially no ink absorbing ability. In addition to ordinary non-coated paper, coated paper, and the like, various non-absorbing plastics used in so-called soft packaging and films thereof are used. Examples of various plastic films include polyethylene terephthalate (PET) film, stretched polystyrene (OPS) film, stretched polypropylene (OPP) film, stretched nylon (ONy) film, polyvinyl chloride (PVC) film, polyethylene (PE) film, triaceti It includes cellulose (TAC) film or the like. As other plastics, polycarbonate, acrylic resin, ABS, polyacetal, polyvinyl alcohol (PVA), rubbers and the like can be used. Moreover, it is applicable also to metals and glass. Among these recording media, the configuration of the present invention is effective particularly when an image is formed on a PET film, OPS film, OPP film, ONy film, or PVC film that can be shrunk by heat. These substrates are not only susceptible to curling and deformation of the film due to ink curing shrinkage and heat generation during the curing reaction, but also the ink film is difficult to follow the substrate shrinkage.

  The surface energies of these various plastic films differ greatly, and depending on the recording medium, the dot diameter after ink landing has been a problem in the past. The ink according to the present invention forms a good high-definition image on a wide range of recording media having a surface energy of 35 to 60 mN / m, including OPP films having a low surface energy, OPS films, and PET having a relatively large surface energy. it can.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<Preparation of ink>
[Preparation of magenta ink 1: radical polymerizable ink]
<Preparation of magenta pigment dispersion 1>
The pigment was dispersed with the following composition.

  The following compounds were placed in a stainless beaker and dissolved by heating and stirring for 1 hour while heating on a 65 ° C. hot plate.

PB824 (Ajinomoto Fine Techno Co., Ltd. Dispersant) 8 parts Tetraethylene glycol diacrylate (bifunctional) 72 parts After cooling to room temperature, 20 parts of the following pigment is added to this and placed in a glass bottle with 200 g of zirconia beads having a diameter of 0.5 mm Sealed and dispersed for 10 hours with a paint shaker, and then the zirconia beads were removed to obtain a magenta pigment dispersion 1.

Pigment: C.I. I. Pigment Red 122 (manufactured by Clariant: PV FAST PINK E)
<Preparation of magenta ink 1>
Using the magenta pigment dispersion prepared above, magenta ink 1 having the following composition was prepared and filtered through a Teflon (registered trademark) 3 μm membrane filter defined by JIS K 5600 manufactured by ADVATEC. The viscosity of this magenta ink 1 at 25 ° C. was 30 mPa · s.

Magenta pigment dispersion 1 20.0 parts Photopolymerizable compound (lauryl acrylate: monofunctional) 19.9 parts Photopolymerizable compound (tetraethylene glycol diacrylate: bifunctional) 25.0 parts Photopolymerizable compound (trimethylolpropane) (Triacrylate: trifunctional) 30.0 parts modified silicone oil (SDX-1843: manufactured by Asahi Denka Kogyo Co., Ltd.) 0.1 parts photo radical initiator (Irgacure 184: manufactured by Ciba Specialty Chemicals)
2.5 parts photoradical initiator (Irgacure 819: Ciba Specialty Chemicals)
2.5 parts [Preparation of magenta ink 2: cationic polymerizable ink]
(Preparation of magenta pigment dispersion 2)
A magenta pigment dispersion 2 was prepared according to the method shown below.

  The following two compounds were placed in a stainless beaker and dissolved while heating and stirring on a hot plate at 65 ° C.

Azisper PB822 (dispersant manufactured by Ajinomoto Fine Techno Co., Ltd.) 8 parts by mass Aron Oxetane OXT-221 (Oxetane compound manufactured by Toagosei Co., Ltd.) 72 parts by mass Next, after cooling to room temperature, C.I. I. Add 20 parts by weight of Pigment Red 122 (supra), put it in a glass bottle together with 200 parts of 0.3 mm diameter zirconia beads, seal it for 4 hours using a paint shaker, and then remove the zirconia beads. Thus, a magenta pigment dispersion 2 was prepared.

(Preparation of magenta ink 2)
Using the magenta pigment dispersion 2 prepared above (magenta pigment: 20% by mass, dispersant PB822: 8% by mass, photopolymerizable compound OXT-221: 72% by mass) and the following additives, magenta ink 2 was prepared.

  Specifically, after mixing all the following additives other than the magenta pigment dispersion 2 and confirming that they were sufficiently dissolved, this mixed solution was added to the magenta pigment dispersion 2 little by little while stirring. After stirring for 15 minutes, filtration was performed with a PP3 μm disk filter manufactured by Loki Techno.

Magenta pigment dispersion 2 20.0 parts by mass Addis Bar PB822 (manufactured by Ajinomoto Fine Techno) 2.0 parts by mass Oxetane OXT-221 (manufactured by Toagosei) 55.0 parts by mass Oxetane OXT-212 (manufactured by Toagosei) 5.0 mass Part Oxetane OXT-211 (manufactured by Toagosei Co., Ltd.) 5.0 parts by mass Alicyclic epoxy compound 1 18.0 parts by mass Photoacid generator 1 (molecular weight 466, having 3 aryl groups per molecular weight)
4.0 parts by weight Polymerization inhibitor (triisopropanolamine) 0.1 parts by weight

  Next, the magenta ink 2 was degassed using a degassing module (Dainippon Ink Chemical Co., Ltd., SEPAREL PF-004D) using a hollow fiber membrane. The viscosity of this magenta ink 2 at 25 ° C. was 31 mPa · s.

<< Sample preparation >>
[Preparation of Sample 1]
1) Blending step The following additives were blended.

Ethylene-propylene-diene rubber 100 parts Softener (stearic acid) 50 parts Vulcanizing agent (sulfur) 5 parts Anti-aging agent 1 part 2) Processing step After mixing the above mixture, the mixture is kneaded using a Burberry mixer, and pellets Was made.

3) Vulcanization / Molding Step The above pellets were put into a mold, pressed, and heated to produce a test plate having a width of 30 mm, a length of 100 mm, and a thickness of 5 mm.

[Preparation of Sample 2]
Sample 2 was prepared in the same manner as in the preparation of Sample 1, except that 0.005% of butyl chloride was added to the ethylene-propylene-diene rubber.

[Preparation of Samples 3 to 8]
Samples 3 to 8 were prepared in the same manner as in the preparation of Sample 1, except that butyl chloride was added to the ethylene-propylene-diene rubber in the amounts shown in Table 1.

[Preparation of Sample 9]
Sample 9 was prepared in the same manner as in the preparation of Sample 5, except that the softener (stearic acid) was omitted.

《Sample evaluation》
About each produced said sample, according to the following method, measurement of rubber hardness and evaluation of ink resistance were performed.

[Measurement of rubber hardness]
About each sample, rubber hardness (Shore A) was measured using a durometer in accordance with the method described in JIS K 6253.

[Evaluation of ink resistance]
After measuring the volume V ₀ before immersion in the ink liquid of each sample, the magenta ink 1 and the magenta ink 2 were each subjected to an immersion treatment at 70 ° C. for 7 days. After immersing, the ink adhering to the sample surface was wiped off, and the body weight V ₁ was measured again to determine the volume change rate (%) according to the method described in JIS K 6528. A measure of gender. The minus display indicates that the volume is reduced, that is, the elution of the softening agent or the like occurs, and the plus display indicates that the sample is swollen. The smaller the absolute value, the better the ink resistance.

  The results obtained as described above are shown in Table 1.

  As is clear from the results shown in Table 1, the comparative sample containing no butyl chloride according to the present invention has a very large volume change rate after being immersed in each ink, and the effect thereof is magenta ink 2 (cationic polymerization). Type ink).

  On the other hand, it can be seen that the sample containing butyl chloride according to the present invention has low rubber hardness and excellent resistance to the magenta ink 1 and the magenta ink 2. In particular, it can be seen that the improvement in ink resistance with respect to the magenta ink 2 (cationic polymerization type ink) is large with respect to the comparative sample.

Example 2
(Inkjet recording device)
The ink jet recording apparatus shown in FIG. 1 was equipped with the ink jet cartridge shown in FIG. 2 and the maintenance unit shown in FIG.

  2. An ink jet recording apparatus in which the elastic member b3 of the ink cartridge shown in FIG. 2 and the member of the cleaning blade 152a of the maintenance unit shown in FIG. 1-9 were prepared.

(Evaluation of long-term durability)
The ink jet recording apparatuses 1 to 9 are loaded with magenta ink 2 (cationic polymerization type ink), and after performing a discharge test for one month in a state where each component is heated to 50 ° C., in the mounting portion of the ink cartridge As a result of visual observation of the ink leakage and the deterioration state of the cleaning blade 152a, in the inkjet recording apparatus 1 of the comparative example, liquid leakage in the ink cartridge and damage to the cleaning blade 152a were observed. In Nos. 2 to 9, liquid leakage from the ink cartridge and damage to the cleaning blade were not observed.

1 is a diagram illustrating an example of an overall configuration of an inkjet recording apparatus that can be applied to the present invention. It is the schematic which shows the main components of an ink cartridge. It is the schematic which shows the other mounting system of an ink cartridge. It is the schematic which shows an example of the maintenance unit with which an inkjet recording device is mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink cartridge 2, 103 Inkjet recording head 3 Active energy ray source 4 Carriage 6 Filter box 7 Intermediate tank 8 Ink supply path 10 Maintenance unit 152a Cleaning blade P Recording material b1 Inner bag b2 Ink lead-out part (female joint)
c1 housing c2 lid d1 detection plate B1 male joint

Claims (8)

In a recording head having an ink ejection surface provided with a plurality of ink ejection ports for ejecting ink, and an ink jet recording apparatus for printing an image by the recording head, a portion in contact with the ink, a portion to which the ink adheres, and a rubber system An ink jet recording apparatus, wherein at least one selected from component parts uses ethylene-propylene-diene rubber (EPDM), and the ethylene-propylene-diene rubber (EPDM) contains butyl halide. 2. The inkjet recording according to claim 1, wherein a content of the butyl halide with respect to a total mass of the ethylene-propylene-diene rubber (EPDM) is 0.01% by mass or more and 0.5% by mass or less. apparatus. The inkjet recording apparatus according to claim 1, wherein the butyl halide is butyl chloride. The inkjet recording according to any one of claims 1 to 3, wherein the ethylene-propylene-diene rubber (EPDM) containing the halogenated butyl is used in a maintenance unit for cleaning the recording head. apparatus. The inkjet recording apparatus according to any one of claims 1 to 4, wherein the ethylene-propylene-diene rubber (EPDM) containing the halogenated butyl is used in an ink cartridge for supplying the ink. . 6. The ink according to claim 1, wherein the ink is an active energy ray-curable inkjet ink containing an active energy ray-curable compound that is cured by irradiation with active energy rays, and the active energy rays are ultraviolet rays. 2. An ink jet recording apparatus according to item 1. The ink according to any one of claims 1 to 6, wherein the ink is an ultraviolet curable inkjet ink containing an ultraviolet curable compound that is cured by ultraviolet irradiation, and the ultraviolet curable compound is a cationic polymerizable compound. The inkjet recording apparatus according to Item. An ink cartridge, wherein at least one of a portion in contact with ink or a portion to which ink is attached is made of ethylene-propylene-diene rubber (EPDM) containing butyl halide.

Images