JP2010121034A - Ink, inkjet recording method, ink cartridge, recording unit and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a red ink that forms an image exhibiting far more excellent glossiness than conventional inks and is suitably applicable for inkjet. <P>SOLUTION: The ink comprise at least C.I. Pigment Red 254 as a pigment and further contains a 1, 2-alkanediol and a polyoxyethylene alkyl ether. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink containing a specific pigment, an ink jet recording method using the ink, an ink cartridge, a recording unit, and an ink jet recording apparatus that can be suitably applied to ink jet.

  In order to improve the light fastness, gas resistance and water fastness of the image obtained by the ink jet recording method, pigment ink containing a pigment as a coloring material has been used. . However, in comparison with a dye ink containing a dye used as a coloring material in the same manner as a pigment, when a pigment ink is used, the color developability of the resulting image may be inferior, and a glossy recording medium However, there is a problem that the glossiness of the image cannot be obtained sufficiently.

  With regard to color development, when using inks of the three primary colors of cyan, magenta, and yellow, the image formed with the conventional pigment ink has a narrow color reproduction area compared with the image recorded with the dye ink, and sufficient It could not be said that color development was obtained. For this reason, even for inks using pigments, which are color materials with excellent fastness properties, it is strongly required to expand the color reproduction region. For example, in addition to the basic three primary color inks, a so-called special color ink using a color material having a hue other than the basic three primary colors such as red, green, blue, orange, violet, etc. is added to increase the color reproduction region. (See Patent Documents 1 and 2). In order to increase the saturation of the color reproduction region recorded with red ink, C.I. I. There are proposals related to ink using Pigment Red 254 and ink sets containing the ink (see Patent Documents 3 and 4).

Regarding the glossiness, since the pigment has a particle shape, the glossiness of an image obtained when recording on a glossy recording medium using pigment ink is still not at a sufficient level. This is due to the following reasons. The pigment ink used in the ink jet recording method usually contains a pigment having an average particle diameter of about 100 nm in a dispersed state in the ink. When such an ink is applied to a glossy recording medium, since the pigment does not have a particle size and unlike a dye that penetrates the recording medium, the pigment does not easily penetrate the pores of the ink receiving layer of the recording medium. It settles on or near the surface. For this reason, in the glossy recording medium, the smoothness is relatively lowered in the region where the ink is applied compared to the region where the ink is not applied, and the glossiness is lowered. For this reason, there is a proposal regarding the inclusion of 1,2-alkanediol in the ink for the purpose of improving the glossiness of the image by increasing the smoothness of the ink dots formed on the surface of the recording medium ( (See Patent Document 5).
WO99 / 05230 Pamphlet JP 2000-248217 A JP 2004-155830 A JP 2007-119708 A JP 2005-194500 A

  Accordingly, the present inventors have proposed C.I., which is a pigment having a preferred red hue. I. We focused on Pigment Red 254. Then, studies were conducted to make the glossiness of an image obtained using a red ink containing the pigment much higher than the conventional level. Specifically, an ink containing both the pigment and 1,2-alkanediol was examined. As a result, it was confirmed that the combined use of the pigment and 1,2-alkanediol improves the glossiness of the obtained image to some extent as compared to the case where the pigment is not used in combination. However, it has been found that as the amount of ink applied to the recording medium increases, that is, as the plurality of dots overlap, the glossiness of the image decreases and still does not reach an excellent level of glossiness. In other words, the pigment is an ink that can provide an image having a sufficient level of gloss even when used in combination with 1,2-alkanediol, which is conventionally considered to improve the gloss of an image. I knew it would n’t be.

  Therefore, an object of the present invention is to provide a red ink that can form an image having a gloss that is far superior to that of conventional inks and that can be suitably applied to inkjet. . Another object of the present invention is to provide an ink jet recording method, an ink cartridge, a recording unit, and an ink jet recording apparatus using the ink.

  The above object is achieved by the present invention described below. That is, the ink according to the present invention contains at least C.I. I. An ink containing CI Pigment Red 254, which further contains 1,2-alkanediol and polyoxyethylene alkyl ether.

  An ink jet recording method according to another embodiment of the present invention is an ink jet recording method in which ink is ejected by an ink jet method to perform recording on a recording medium, wherein the ink is an ink having the above-described configuration. And

  An ink cartridge according to another embodiment of the present invention is an ink cartridge including an ink storage portion that stores ink, wherein the ink is ink having the above-described configuration.

  Further, a recording unit according to another embodiment of the present invention is a recording unit including an ink storage portion that stores ink and a recording head for discharging ink, wherein the ink has the above-described configuration. It is characterized by being the ink of this.

  In addition, an ink jet recording apparatus according to another embodiment of the present invention is an ink jet recording apparatus including an ink containing portion that contains ink, and a recording head for ejecting ink, wherein the ink includes: The ink is configured as described above.

  ADVANTAGE OF THE INVENTION According to this invention, the red ink which can form the image which has the gloss which was far superior compared with the conventional ink, and can be applied suitably also for inkjet can be provided. According to another embodiment of the present invention, an ink jet recording method, an ink cartridge, a recording unit, and an ink jet recording apparatus using the ink can be provided.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments. In the following description, C.I. I. Pigment Red 254 may be simply referred to as “pigment”.

  The present invention relates to C.I. I. The present invention has been made to solve the above-described technical problems that occur in inks containing CI Pigment Red 254 and 1,2-alkanediol. In order to solve the above technical problem, the present inventors have proposed C.I. I. The gloss level of the image obtained by adding various compounds to the ink containing CI Pigment Red 254 and 1,2-alkanediol was examined. As a result, C.I. I. It has been found that the glossiness of the image is remarkably improved by adding polyoxyethylene alkyl ether to the ink containing CI Pigment Red 254 and 1,2-alkanediol. The present inventors consider the mechanism of improving the glossiness of an image by using polyoxyethylene alkyl ether as follows.

  As described above, the glossiness of the image is not sufficiently obtained because the surface smoothness of the image is low. Therefore, in order to improve the glossiness of the image, it can be said that the dot (image) should have high smoothness even in a region where a plurality of dots overlap. In addition, if the dots have high smoothness, it is difficult to recognize the level difference between the non-recording portion and the image portion of the recording medium, and uniform glossiness is exhibited over the entire area of the recording medium.

  Here, in order to improve the smoothness of the dots, the following may be performed. That is, when ink in the form of droplets ejected from the recording head adheres to the recording medium and ink dots are formed, before the liquid component such as an aqueous medium in the ink is absorbed by the recording medium, What is necessary is just to make it so that the dot spreads quickly on the surface of the recording medium. That is, the ink that easily spreads on the surface of the recording medium can suppress the height of the formed dots as compared with the ink that hardly wets and spreads. In this way, since the level difference between the non-recording portion of the recording medium and the dot-formed portion (image portion) is suppressed, the ink with high wettability is more glossy than the ink with low wettability. Is significantly improved.

  1,2-alkanediol has the effect of quickly reducing the interfacial tension of the droplet immediately after the ink is ejected from the recording head, that is, when the droplet is formed. For this reason, it is considered that the ink containing 1,2-alkanediol tends to wet and spread on the surface of the recording medium and can improve the glossiness of the image to some extent.

  In so-called multi-pass recording that is frequently used in recent years in the ink jet recording method in order to further improve the image quality, there is a problem that the glossiness of the obtained image tends to decrease. This multi-pass recording is a method of recording an image of a unit area by causing the recording head to scan twice or more in the main scanning direction. The image is obtained by scanning the recording head n times with respect to the unit area of the recording medium. Is an n-pass recording (n is 1 or more). The unit area refers to one pixel corresponding to the resolution or one band that is an area of an image formed by one scan of the recording head, and can be set as various areas.

  When performing multi-pass printing, after the dots formed in the previous printing pass are fixed on the printing medium, dots are formed in the subsequent printing pass, and at least the edges of these dots overlap. There are many cases. For this reason, when multi-pass printing is performed, a level difference is generated between a plurality of dots, so that the smoothness of the dots becomes lower and the glossiness tends to decrease. Therefore, even when performing multi-pass printing, in order to obtain a high level of glossiness of the image, the dots formed in the previous printing pass and the dots formed thereon, that is, the subsequent printing pass are used. It is necessary to consider compatibility with the applied dots. For example, if ink droplets to be applied later are made compatible with dots formed earlier, that is, dots that are substantially fixed on the recording medium, steps between the plurality of dots are suppressed. Since the smoothness is high, the gloss can be improved.

  As a result of the study by the present inventors based on the above technical idea, the C.I. I. The ink composition was such that polyoxyethylene alkyl ether was further contained in the ink containing CI Pigment Red 254 and 1,2-alkanediol. According to the ink having such a configuration, it is possible to slightly increase the time until the previously formed dots are fixed on the recording medium. For this reason, by improving the compatibility between the previously formed dots and the ink droplets applied thereon, the step between the dots is suppressed, the smoothness is increased, and the glossiness is remarkably improved. I think that.

<Ink>
Hereinafter, the components constituting the ink of the present invention will be described in detail.

(Pigment: CI Pigment Red 254)
The pigment used in the ink of the present invention is C.I. I. Pigment Red 254. The pigment content (% by mass) in the ink is 0.1% by mass or more and 15.0% by mass or less, more preferably 0.5% by mass or more and 10.0% by mass or less based on the total mass of the ink. preferable. As a dispersion method of the pigment in the aqueous medium constituting the ink, a resin dispersion type pigment (resin dispersion type pigment) in which the pigment is dispersed using a resin as a dispersant, or a hydrophilic group is introduced on the surface of the pigment particle. Self-dispersed pigments (self-dispersed pigments) can be used. Also, pigments (resin-bonded self-dispersing pigments) in which organic groups containing polymers are chemically bonded to the surface of the pigment particles, or microcapsule types in which at least a part of the surface of the pigment particles is coated with a resin or the like Pigments can also be used. Of course, these pigments having different dispersion methods may be used in combination.

(Resin dispersion type pigment)
When using a resin dispersion type pigment in which a pigment is dispersed using a resin as a dispersant, the resin dispersant is preferably one that can disperse the pigment in an aqueous medium by the action of an anionic group. Specific examples of the resin that can be used as the dispersant include the following. Styrene-acrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer. Styrene-maleic acid copolymer, styrene-maleic acid-acrylic acid alkyl ester copolymer. Styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer. Styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, styrene-maleic anhydride-maleic acid half ester copolymer, or salts thereof.

  In the present invention, the resin used as the dispersant is preferably one having an acid value of 50 mgKOH / g or more and 300 mgKOH / g or less. Further, it is preferable to use a resin having a weight average molecular weight of 1,000 to 30,000, more preferably 3,000 to 15,000. The resin content in the ink is 0.1 to 3.0 times by mass with respect to the pigment content in the ink, that is, the resin content / pigment content. The amount is preferably 0.1 or more and 3.0 or less. In this case, the value of the content of the resin and the pigment is the content of each component based on the total mass of the ink.

(Self-dispersing pigment)
In the case of using a self-dispersion type pigment having a hydrophilic group introduced on the surface of the pigment particle, it is preferable to use an ionic group such as an anionic group as the hydrophilic group. Self-dispersing pigments are those that can disperse the pigment in an aqueous medium without using a dispersant. Examples of such a self-dispersing pigment include an anionic pigment in which an ionic group such as an anionic group is bonded to the surface of pigment particles. The ionic group, specifically, for _{example, -COOM, -SO 3 M, -PO} 3 HM, and the like _-PO 3 _{M 2.} In the above formula, M is a hydrogen atom, alkali metal, ammonium, or organic ammonium, and R is an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group. . Among those represented as “M” in the anionic group, specific examples of the alkali metal include Li, Na, K, Rb, and Cs. Moreover, as a specific example of organic ammonium, the following are mentioned, for example. That is, methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, methanolammonium, dimethanolammonium, trimethanolammonium and the like can be mentioned.

[Resin-bonded self-dispersing pigment]
When using a pigment in which an organic group containing a polymer is chemically bonded to the surface of the pigment particle, a functional group chemically bonded to the surface of the pigment particle directly or through another atomic group, and ionicity It is preferable to use those containing a reaction product of a copolymer of a monomer and a hydrophobic monomer. Such resin-bonded self-dispersing pigments can also be dispersed in an aqueous medium without using a dispersant.

[Microcapsule type pigment]
When a microcapsule type pigment in which at least a part of the surface of the pigment particle is coated with a resin or the like is used, a method for microencapsulating the pigment includes a chemical production method, a physical production method, a physicochemical method, a mechanical production method, etc. The conventionally known method can be used. Specifically, for example, interfacial polymerization method, in-situ polymerization method, submerged cured coating method, coacervation (phase separation) method, submerged drying method, melt dispersion cooling method, air suspension coating method, spray Examples thereof include a drying method, an acid precipitation method, and a phase inversion emulsification method. It is preferable to use a resin such as an organic polymer compound as the substance that coats the surface of the pigment particles.

<1,2-alkanediol>
The ink of the present invention needs to contain 1,2-alkanediol. Examples of the 1,2-alkanediol include 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2- Examples include octanediol and 1,2-nonanediol. The content (% by mass) of 1,2-alkanediol in the ink is 1.0% by mass or more and 20.0% by mass or less, and further 1.0% by mass or more and 10.0% by mass based on the total mass of the ink. % Or less is preferable.

  The 1,2-alkanediol used in the ink of the present invention preferably has 5 to 8 carbon atoms in the alkyl group. Specifically, it is preferably at least one selected from 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol. When the number of carbon atoms is less than 5, the effect of improving the glossiness of the image may be reduced. When the number of carbon atoms exceeds 8, it hardly dissolves in water, and some co-solvent is required to dissolve in water. There is a case.

<Polyoxyethylene alkyl ether>
The ink of the present invention needs to contain polyoxyethylene alkyl ether. The polyoxyethylene alkyl ether has a structure represented by the following formula. The content (% by mass) of the polyoxyethylene alkyl ether in the ink is 0.1% by mass or more and 5.0% by mass or less, and further 0.1% by mass or more and 3.0% by mass based on the total mass of the ink. The following is preferable.

(In the above formula, R is an alkyl group, and n is an integer.)
The polyoxyethylene alkyl ether used in the ink of the present invention has a hydrophobic group in which the carbon number of R (alkyl group) in the above formula has a surface activity, for example, 12 to 22 carbon atoms. I just need it. Specific examples include a lauryl group (12), a cetyl group (16), a stearyl group (18), an oleyl group (18), a behenyl group (22), etc. Number). Further, n in the above formula which is a hydrophilic part of polyoxyethylene alkyl ether, that is, the number of ethylene oxide groups is preferably 10 or more and 40 or less.

  It is preferable to use a polyoxyethylene alkyl ether having an HLB value determined by the Griffin method of 13 or more and 20 or less. If the HLB value is less than 13, the effect of alleviating dot fixing is reduced, and the effect of improving glossiness may not be sufficiently obtained. The upper limit of the HLB value is 20 as will be described later, and the upper limit of the HLB value of the polyoxyethylene alkyl ether that can be used in the present invention is 20 or less.

  Here, the Griffin method will be described. The HLB value by the Griffin method can be obtained from the following formula (1) from the formula weight and molecular weight of the hydrophilic group of the surfactant. The HLB value by the Griffin method indicates the degree of hydrophilicity or lipophilicity of the surfactant, and takes a value of 0 to 20. The lower the HLB value, the higher the lipophilicity or hydrophobicity of the surfactant. Conversely, the higher the HLB value, the higher the hydrophilicity of the surfactant.

(Aqueous medium)
For the ink, water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent can be used. The content (% by mass) of the water-soluble organic solvent in the ink is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink.

The water-soluble organic solvent is not particularly limited as long as it is water-soluble, and those listed below can be used alone or in combination of two or more. Specifically, for example, the following water-soluble organic solvents can be used.
C1-C4 alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol. 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol and the like mentioned above -Alkanediols other than alkanediols. Carboxylic acid amides such as N, N-dimethylformamide and N, N-dimethylacetamide. Ketones or ketoalcohols such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one; Cyclic ethers such as tetrahydrofuran and dioxane. Alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, butylene glycol, hexylene glycol and thiodiglycol; Polyhydric alcohols such as glycerin, 1,2,6-hexanetriol, and acetylene glycol derivatives; Alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monoethyl (or butyl) ether. Polyalkylene glycols such as polyethylene glycol and polypropylene glycol having an average molecular weight of 200 to 1,000. Heterocycles such as 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylmorpholine. Sulfur-containing compounds such as dimethyl sulfoxide.

  It is preferable to use deionized water (ion exchange water) as the water. The content (% by mass) of water in the ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink.

(Other ingredients)
In addition to the above components, the ink may contain a water-soluble organic compound that is solid at room temperature, such as urea, urea derivatives, trimethylolpropane, and trimethylolethane. In addition, various additives such as a surfactant, an antifoaming agent, a pH adjusting agent, an antiseptic, and an antifungal agent may be contained in order to obtain an ink having a desired physical property value as necessary.

<Inkjet recording method>
The ink of the present invention is used in the ink jet recording method of the present invention in which recording is performed on a recording medium by ejecting the ink by an ink jet method. Ink jet recording methods include a recording method in which ink is ejected by applying mechanical energy to the ink, and a recording method in which ink is ejected by applying thermal energy to the ink. In particular, in the present invention, an ink jet recording method using thermal energy can be preferably used.

<Ink cartridge>
As an ink cartridge suitable for performing recording using the ink of the present invention, the ink cartridge of the present invention provided with an ink storage portion for storing such ink can be mentioned.

<Recording unit>
As a recording unit suitable for performing recording using the ink of the present invention, there is a recording unit of the present invention provided with an ink storage portion for storing such ink and a recording head for discharging the ink. In particular, a recording unit in which the recording head ejects ink by applying thermal energy corresponding to the recording signal to the ink can be preferably used. In particular, in the present invention, it is preferable to use a recording head having a heat generating part wetted surface containing a metal and / or a metal oxide. Specific examples of the metal and / or metal oxide constituting the heat generating part wetted surface include, for example, metals such as Ta, Zr, Ti, Ni, and Al, and oxides of these metals. .

<Inkjet recording apparatus>
As an ink jet recording apparatus suitable for performing recording using the ink of the present invention, an ink jet recording apparatus of the present invention including an ink storage portion for storing such ink and a recording head for discharging the ink can be cited. It is done. In particular, there is an ink jet recording apparatus that ejects ink by applying thermal energy corresponding to a recording signal to ink inside a recording head having an ink storage portion that stores the ink.

  Below, the schematic structure of the mechanism part of an inkjet recording device is demonstrated. The ink jet recording apparatus is composed of a paper feed unit, a transport unit, a carriage unit, a paper discharge unit, a cleaning unit, and an exterior unit that protects these parts and provides design properties in accordance with the role of each mechanism.

  FIG. 1 is a perspective view of the ink jet recording apparatus. 2 and 3 are diagrams for explaining the internal mechanism of the ink jet recording apparatus. FIG. 2 is a perspective view from the upper right part, and FIG. 3 is a side sectional view of the ink jet recording apparatus.

  When paper is fed, only a predetermined number of recording media are fed to a nip portion composed of a paper feed roller M2080 and a separation roller M2041 in a paper feed unit including a paper feed tray M2060. The recording medium is separated at the nip portion, and only the uppermost recording medium is conveyed. The recording medium conveyed to the conveyance unit is guided by the pinch roller holder M3000 and the paper guide flapper M3030, and conveyed to the roller pair of the conveyance roller M3060 and the pinch roller M3070. The roller pair of the conveyance roller M3060 and the pinch roller M3070 is rotated by driving of the LF motor E0002, and the recording medium is conveyed on the platen M3040 by this rotation.

  When forming an image on a recording medium, the carriage unit arranges a recording head H1001 (FIG. 4; a detailed configuration will be described later) at a position where a target image is formed, and follows a signal from the electric board E0014. Ink is ejected onto the recording medium. An image is formed on the recording medium by alternately repeating main scanning in which the carriage M4000 scans in the column direction while performing recording by the recording head H1001 and sub-scanning in which the recording medium is conveyed in the row direction by the conveyance roller M3060. The recording medium on which the image is formed is conveyed in a state sandwiched between the nips of the first paper discharge roller M3110 and the spur M3120 at the paper discharge unit, and is discharged to the paper discharge tray M3160.

  The cleaning unit cleans the recording head H1001 before and after forming an image. When the pump M5000 is operated with the cap M5010 capping the ejection port of the recording head H1001, unnecessary ink or the like is sucked from the ejection port of the recording head H1001. In addition, by sucking ink remaining in the cap M5010 with the cap M5010 open, sticking due to the remaining ink and other problems do not occur.

(Configuration of recording head)
The configuration of the head cartridge H1000 will be described. FIG. 4 is a diagram showing the configuration of the head cartridge H1000, and is a diagram showing how the ink cartridge H1900 is mounted on the head cartridge H1000. The head cartridge H1000 has a recording head H1001, means for mounting the ink cartridge H1900, and means for supplying ink from the ink cartridge H1900 to the recording head, and is detachably mounted on the carriage M4000.

  The ink jet recording apparatus forms an image with each of yellow, magenta, cyan, black, light magenta, light cyan, and red inks. Therefore, the ink cartridge H1900 is also prepared for seven colors independently. In the above, the ink of the present invention is used as at least one ink. As shown in FIG. 4, each ink cartridge H1900 is detachable from the head cartridge H1000. The ink cartridge H1900 can be attached and detached even when the head cartridge H1000 is mounted on the carriage M4000.

  FIG. 5 is an exploded perspective view of the head cartridge H1000. The head cartridge H1000 includes a recording element substrate, a plate, an electric wiring substrate H1300, a cartridge holder H1500, a flow path forming member H1600, a filter H1700, a seal rubber H1800, and the like. The recording element substrate is composed of a first recording element substrate H1100 and a second recording element substrate H1101, and the plate is composed of a first plate H1200 and a second plate H1400.

  The first recording element substrate H1100 and the second recording element substrate H1101 are Si substrates, and a plurality of recording elements (nozzles) for ejecting ink are formed on one side thereof by a photolithography technique. Electric wiring such as Al for supplying electric power to each recording element is formed by a film forming technique, and a plurality of ink flow paths corresponding to individual recording elements are formed by a photolithography technique. Further, an ink supply port for supplying ink to the plurality of ink flow paths is formed to open on the back surface.

  FIG. 6 is an enlarged front view illustrating the configuration of the first recording element substrate H1100 and the second recording element substrate H1101. H2000 to H2600 are arrays of printing elements corresponding to different ink colors (hereinafter also referred to as nozzle arrays). On the first recording element substrate H1100, nozzle rows for three colors, a nozzle row H2000 for yellow ink, a nozzle row H2100 for magenta ink, and a nozzle row H2200 for cyan ink, are formed. On the second recording element substrate H1101, nozzle rows for four colors, a light cyan ink nozzle row H2300, a black ink nozzle row H2400, a red ink nozzle row H2500, and a light magenta ink nozzle row H2600, are formed. ing. Each nozzle row is composed of a plurality of nozzles arranged at a predetermined interval in the recording medium conveyance direction (sub-scanning direction). The number of nozzles may be the same or different for each type of ink.

  Hereinafter, a description will be given with reference to FIGS. The first recording element substrate H1100 and the second recording element substrate H1101 are bonded and fixed to the first plate H1200. Here, an ink supply port H1201 for supplying ink to the first recording element substrate H1100 and the second recording element substrate H1101 is formed. Further, a second plate H1400 having an opening is bonded and fixed to the first plate H1200. The second plate H1400 holds the electrical wiring substrate H1300 so that the electrical wiring substrate H1300 is electrically connected to the first recording element substrate H1100 and the second recording element substrate H1101.

  The electrical wiring substrate H1300 applies an electrical signal for ejecting ink from each nozzle formed on the first recording element substrate H1100 and the second recording element substrate H1101. The electric wiring board H1300 is arranged on the electric wiring corresponding to the first recording element substrate H1100 and the second recording element substrate H1101, and an external part for receiving an electric signal from the ink jet recording apparatus. And a signal input terminal H1301. The external signal input terminal H1301 is positioned and fixed on the back side of the cartridge holder H1500.

  A flow path forming member H1600 is fixed to the cartridge holder H1500 that holds the ink cartridge H1900, for example, by ultrasonic welding, and forms an ink flow path H1501 that communicates from the ink cartridge H1900 to the first plate H1200. A filter H1700 is provided at the ink cartridge side end of the ink flow path H1501 that engages with the ink cartridge H1900, and can prevent dust from entering from the outside. Further, a seal rubber H1800 is attached to the engaging portion with the ink cartridge H1900 so that the ink can be prevented from evaporating from the engaging portion.

  Furthermore, as described above, the head cartridge H1000 is configured by bonding the cartridge holder portion and the recording head portion H1001 by bonding or the like. The cartridge holder portion includes a cartridge holder H1500, a flow path forming member H1600, a filter H1700, and a seal rubber H1800. The recording head portion H1001 includes a first recording element substrate H1100, a second recording element substrate H1101, a first plate H1200, an electric wiring substrate H1300, and a second plate H1400.

  Here, as an embodiment of the recording head, a thermal ink jet recording head that performs recording using an electrothermal transducer (recording element) that generates thermal energy for causing ink to cause film boiling in accordance with an electrical signal. Said. About this typical structure and principle, for example, what is performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 is preferable. . This method can be applied to both a so-called on-demand type and a continuous type.

  The thermal ink jet method is particularly effective when applied to an on-demand type. In the case of the on-demand type, at least one drive that applies a rapid temperature rise exceeding nucleate boiling corresponding to the recording information to the electrothermal transducer disposed corresponding to the liquid flow path holding the ink Apply a signal. As a result, thermal energy is generated in the electrothermal transducer, and film boiling occurs in the ink. As a result, bubbles in the ink corresponding to the drive signal on a one-to-one basis can be formed. At least one droplet is formed by ejecting ink through the ejection port by the growth and contraction of the bubbles. It is more preferable that the driving signal has a pulse shape, since the bubble grows and contracts immediately and appropriately, so that ink discharge with particularly excellent response can be achieved.

  The ink of the present invention is not limited to the thermal ink jet method, and can be preferably used in an ink jet recording apparatus using mechanical energy as described below. An ink jet recording apparatus having such a configuration includes a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material disposed to face the nozzles, and ink filling the periphery of the pressure generating element. Become. Then, the pressure generating element is displaced by the applied voltage, and ink is ejected from the nozzle.

  As described above, the ink jet recording apparatus is not limited to one in which the recording head and the ink cartridge are separated from each other. Further, the ink cartridge is integrated with the recording head in a separable or non-separable manner and mounted on the carriage, and is provided at a fixed portion of the ink jet recording apparatus via an ink supply member such as a tube. An ink may be supplied to the recording head. Further, when the ink cartridge is provided with a configuration for applying a preferable negative pressure to the recording head, the following configuration can be adopted. That is, a mode in which an absorber is disposed in the ink storage portion of the ink cartridge, or a mode in which a flexible ink storage bag and a spring portion that applies a biasing force in the direction of expanding the inner volume of the flexible ink storage bag are provided. It can be. In addition to the serial type recording method described above, the ink jet recording apparatus may also take the form of a line printer in which recording elements are aligned over a range corresponding to the entire width of the recording medium.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, unless the summary is exceeded, this invention is not limited by the following Example. In the following description, “parts” and “%” are based on mass unless otherwise specified.

<Preparation of pigment dispersion>
10 parts of a pigment (CI Pigment Red 254), 20 parts of a dispersant, and 70 parts of ion-exchanged water were mixed and dispersed for 3 hours using a batch type vertical sand mill. As the dispersant, one obtained by neutralizing a styrene-acrylic acid copolymer having an acid value of 210 mgKOH / g and a weight average molecular weight of 8,000 with a 10% aqueous sodium hydroxide solution was used. After removing coarse particles by centrifugation, the mixture is further filtered under pressure with a cellulose acetate filter (manufactured by Advantech) having a pore size of 3.0 μm, and the pigment content is 10% and the resin (dispersant) content is 20. % Pigment dispersion was obtained.

<Preparation of ink>
The components shown in Table 1 below were mixed and sufficiently stirred, and then pressure filtration was performed with a cellulose acetate filter having a pore size of 0.8 μm (manufactured by Advantech) to prepare inks of Examples and Comparative Examples. In Table 1 below, EMALEX 709 and 712, and NIKKOL BC-40TX are all polyoxyethylene alkyl ethers, and the number of these alkyl groups (R), ethylene oxide groups (n), and HLB values are respectively It is as follows.
EMALEX 709: R = lauryl group, n = 9, HLB value = 12 (manufactured by Nippon Emulsion)
EMALEX 712: R = lauryl group, n = 12, HLB value = 13 (manufactured by Nippon Emulsion)
NIKKOL BC-40TX: R = cetyl group, n = 40, HLB value = 20 (manufactured by Nikko Chemicals)

<Evaluation>
The ink cartridges filled with the inks of Examples and Comparative Examples obtained above were mounted at the magenta ink position of the ink jet recording apparatus (trade name: PIXUS 990i; manufactured by Canon Inc.). Then, solid images with a recording duty of 50% and 150% were recorded on Canon photographic paper / Glossy Gold GL-101 (manufactured by Canon). For each recording duty image of the obtained recorded matter, the glossiness was evaluated by measuring the 20 ° glossiness of the image portion using a micro haze meter plus (manufactured by BYK Gardner). The evaluation criteria for glossiness are as follows. The evaluation results are shown in Table 2.
AA: 20 ° glossiness was 80 or more A: 20 ° glossiness was 60 or more and less than 80 B: 20 ° glossiness was less than 60

It is a perspective view of an inkjet recording device. It is a perspective view of the mechanism part of an inkjet recording device. It is sectional drawing of an inkjet recording device. FIG. 6 is a perspective view illustrating a state where an ink cartridge is mounted on the head cartridge. It is a disassembled perspective view of a head cartridge. FIG. 6 is a front view showing a recording element substrate in the head cartridge.

Explanation of symbols

M2041 Separation roller M2060 Paper feed tray M2080 Paper feed roller M3000 Pinch roller holder M3030 Paper guide flapper M3040 Platen M3060 Transport roller M3070 Pinch roller M3110 Paper discharge roller M3120 Spur M3160 Paper discharge tray M4000F Carriage M5000 Pump M500P Head cartridge H1001 Recording head H1100 First recording element substrate H1101 Second recording element substrate H1200 First plate H1201 Ink supply port H1300 Electrical wiring substrate H1301 External signal input terminal H1400 Second plate H1500 Cartridge holder H1501 Ink channel H1600 Flow path forming member H17 0 filter H1800 seal rubber H1900 ink cartridge H2000 yellow nozzle row H2100 magenta nozzle row H2200 cyan nozzle row H2300 light cyan nozzle row H2400 black nozzle row H2500 Red nozzle row H2600 light magenta nozzle row

Claims (7)

At least as a pigment, C.I. I. An ink containing CI Pigment Red 254,
Further, an ink comprising 1,2-alkanediol and polyoxyethylene alkyl ether.   The 1,2-alkanediol is at least one selected from 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol. Ink.   The ink according to claim 1 or 2, wherein the polyoxyethylene alkyl ether has an HLB value of 13 or more and 20 or less.   4. An ink jet recording method for recording on a recording medium by ejecting ink by an ink jet method, wherein the ink is the ink according to any one of claims 1 to 3.   An ink cartridge comprising an ink containing portion containing ink, wherein the ink is the ink according to any one of claims 1 to 3.   4. A recording unit comprising an ink containing portion containing ink and a recording head for discharging ink, wherein the ink is the ink according to claim 1. Recording unit characterized by.   4. An ink jet recording apparatus comprising an ink containing portion containing ink and a recording head for discharging ink, wherein the ink is the ink according to claim 1. An ink jet recording apparatus.

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