JP5142488B2 - Ink jet ink, ink jet ink manufacturing method, ink jet recording method, ink cartridge, and cyan ink - Google Patents

Description

  The present invention relates to an inkjet ink, a method for manufacturing an inkjet ink, an inkjet recording method ink cartridge, and a cyan ink.

  The ink jet recording method is a recording method in which an ink is applied to a recording medium such as plain paper or glossy media to form an image, and is rapidly spreading due to its low cost and high recording speed. Further, in addition to the progress of higher image quality of recorded materials, with the rapid spread of digital cameras, it has become widespread as a method for outputting an image equivalent to a silver salt photograph. In such an environment, in order to provide a recorded matter that meets the needs of the times, not only the characteristics of the ink used in the ink jet recording method but also the characteristics of the color material have been devised.

  As a coloring material used for cyan ink for inkjet, a dye having excellent color developability or a pigment having excellent water resistance, light resistance, gas resistance, and the like is used. However, when an image is formed with an ink using a dye as a coloring material, the water resistance and light resistance of the image may be inferior compared to an image formed with an ink using a pigment. In order to solve such a problem, there is a proposal for using a dye and a pigment together as a coloring material (see Patent Documents 1 and 2). According to this, while maintaining the excellent color developability of the dye, it is said that water resistance and light resistance, and further, gas resistance of an image formed on a recording medium having a porous ink receiving layer can be improved. .

Japanese Patent Publication No. 60-45668 JP 2001-323196 A

  However, as a result of the study by the present inventors, it has been recognized that when an image is formed using a conventional ink in which a dye and a pigment are used together as a coloring material, a problem may occur in a specific combination of the dye and the pigment. did. In particular, when an image is formed by applying a conventional inkjet ink using a dye having a cyan hue and a pigment having a copper phthalocyanine skeleton to a glossy recording medium, the following problems may occur. . That is, a phenomenon that the reflected light of the obtained image looks red (bronze phenomenon) occurs, and the image quality may be significantly deteriorated. The inventors of the present invention have considered that a user who seeks an image equivalent to a silver salt photograph may not be satisfied with the obtained recorded matter due to the occurrence of such a phenomenon. Accordingly, the present inventors have recognized that it is important to provide an image that can suppress the occurrence of the above-described phenomenon as compared with conventional ink-jet inks and that is also excellent in color developability.

  From the above, the first problem to be solved by the present invention is to suppress the phenomenon that the reflected light of the image looks red, and not only a glossy recording medium (also referred to as glossy paper) but also a normal It is to provide a novel ink jet ink that gives an image excellent in color developability even on paper. More preferably, for example, when an image is formed adjacent to an image formed with a black ink, a novel inkjet ink that provides an image with suppressed bleeding is provided. In addition, the second problem to be solved by the present invention is to reduce the phenomenon that reflected light of an image looks red, and further to provide an ink jet ink that gives an image excellent in color developability economically and environmentally. It is to provide a method of manufacturing by means preferable from the point of view. Furthermore, a third problem to be solved by the present invention is an ink jet recording method using an ink jet ink that suppresses a phenomenon in which reflected light of an image appears red, has excellent color developability, and gives an image in which bleeding is suppressed. And providing an ink cartridge.

As a result of intensive studies to solve the above-described problems, the present inventors have arrived at the present invention. In other words, it means for solving the first problem, water, a coloring material, and an ink jet ink containing a water-soluble organic solvent, before Kiirozai is, C. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9, and a pigment having a copper phthalocyanine skeleton, pre-Symbol-soluble organic solvent comprises a poor solvent for the pigment, the pigment in the ink the content a (% by mass) is, based on the total weight of the ink, less than 1% by mass is, the content of the pigment a (wt%), of the dye relative to the total weight of the ink It is an inkjet ink characterized in that the content D (mass%) satisfies the relationship of 7% ≦ A / D × 100% ≦ 24.3% .

Another means for solving the first problem is a cyan ink used together with a black ink containing water, carbon black, and a water-soluble organic solvent, wherein the water, the coloring material, and the water-soluble and also contains an organic solvent, as the coloring material, C. I. Direct Blue 199, C.I. I. Direct Blue 86 and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9, and contains a pigment having a copper phthalocyanine skeleton, a pre-Symbol-soluble organic solvent includes a poor solvent for the pigment, the prior SL ink the dye content of the pigment a (mass%) of state, and are less than 1% by weight based on the total weight of the ink, the content a (% by mass) of the pigment, relative to the total weight of the ink The cyan ink is characterized in that the content D (mass%) of the ink satisfies a relationship of 7% ≦ A / D × 100% ≦ 24.3% .

Further, it means for solving the second problem is a manufacturing method of the inkjet ink to obtain the ink jet ink before noted configuration, containing pigment having a copper phthalocyanine skeleton, and a poor solvent for the pigment As a color material, an ink cartridge for storing the ink is a C.I. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. An ink-jet ink manufacturing method comprising a step of injecting an ink containing one or more dyes selected from the group consisting of Acid Blue 9.

Also, means for solving the third problem is an inkjet recording method using any one of the inkjet ink, the cyan ink, or the inkjet ink obtained by the inkjet ink manufacturing method, and before SL is an ink cartridge containing one of the inkjet ink.

  ADVANTAGE OF THE INVENTION According to this invention, the ink for inkjet and cyan ink which can suppress the phenomenon in which the reflected light of an image looks red, are excellent also in color developability, and can give the image by which bleeding was suppressed can be provided. . In addition, by reusing the ink jet ink remaining in the ink cartridge, it is possible to produce an ink jet ink manufacturing method that is economical and preferable from the viewpoint of environmental protection. can do. Further, the phenomenon that the reflected light of the image on the recording medium having gloss is particularly red is suppressed, the bleeding on the plain paper in particular is suppressed, and an image having excellent color development on both the glossy recording medium and the plain paper is obtained. An ink jet recording method and an ink cartridge can be provided.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. Hereinafter, in the present invention, the inkjet ink is sometimes referred to as “ink”, and the pigment having a copper phthalocyanine skeleton is simply referred to as “cyan pigment”.
The ink according to the present invention is an ink having a cyan hue. As a coloring material, a dye having a cyan hue and a pigment having a copper phthalocyanine skeleton, such as C.I. I. A phenomenon in which reflected light of an image formed on a glossy recording medium with ink containing both Pigment Blue 15: 3 appears red will be described. This is because C. agglomerated on the surface of the recording medium. I. This is because the light reflected by Pigment Blue 15: 3 (a kind of cyan pigment) causes bronzing (bronze phenomenon) in which a color close to the color complementary to the original color of the cyan pigment is observed. . Therefore, the present inventors examined a cyan pigment that is a cause of causing the bronze phenomenon. As a result, it is effective to set the content of the cyan pigment in the ink to less than 1% by mass and to further contain a poor solvent for the cyan pigment, and in particular, to contain the poor solvent for the cyan pigment in the ink. It has been found that the bronze phenomenon can be more effectively suppressed when the amount is a specific amount. The reason why the bronze phenomenon can be suppressed by such an ink configuration is not clear, but the present inventors presume as follows.

  As described above, since the bronze phenomenon is a phenomenon caused by the cyan pigment in the ink, it can be predicted that the occurrence of the bronze phenomenon can be suppressed as the cyan pigment applied to the glossy recording medium is decreased. Accordingly, the present inventors examined the relationship between the content of cyan pigment in the ink and the bronze phenomenon. As a result, although it varies somewhat depending on the type of cyan pigment, the characteristics of the ink, and the recording method, in many cases, when the content of the cyan pigment in the ink is less than 1% by mass, the occurrence of bronzing is somewhat good. It was found that a good result was obtained. However, it has been found that the occurrence of the bronzing phenomenon may not be suppressed to a sufficiently satisfactory level only by setting the content of the cyan pigment in the ink to less than 1% by mass.

  Accordingly, the present inventors have made further detailed studies focusing on the aggregation state of the cyan pigment applied to the recording medium. As a result, it has been found that the occurrence of bronzing can be suppressed by reducing the regular reflectance of light reflected on the aggregate of cyan pigment present on the surface of the recording medium. In other words, by appropriately aggregating the cyan pigment applied to the recording medium and appropriately reflecting the light reflected on the aggregate of the cyan pigment, it can be an effective means for effectively suppressing the occurrence of the bronze phenomenon. I found.

  The present inventors are effective in rapidly aggregating the cyan pigment on the surface of the recording medium even when the content of the cyan pigment in the ink is less than 1% by mass as in the present invention. I found out. Further, the present inventors have found that the ink needs to contain a poor solvent for the cyan pigment in order to obtain the above-described effect. That is, since the ink contains a poor solvent, after the ink is applied to a glossy recording medium, the aggregation of the cyan pigment accompanying the evaporation and penetration of moisture in the ink occurs rapidly. The unevenness of the cyan pigment aggregate itself and the unevenness of the recording medium and the cyan pigment aggregate increase. As a result, it was found that the light reflected on the recording medium was moderately irregularly reflected, and the bronzing phenomenon can be effectively suppressed.

  Furthermore, it has also been found that by including a poor solvent for the cyan pigment in the ink, another effect can be obtained in addition to the effect of suppressing the bronze phenomenon. That is, when the ink according to the present invention is applied to plain paper, excellent color developability can be obtained, and the color of the image may be blurred due to blurring at the boundary between different color areas or the ink being mixed unevenly. It is possible to suppress the phenomenon of deterioration of quality (hereinafter referred to as “bleeding”). Thus, when the ink according to the present invention is used and recording is performed on plain paper as a recording medium, the present inventors have obtained the following reason why excellent color developability can be obtained and bleeding can be suppressed. I guess so.

  When the ink according to the present invention is applied to a recording medium, particularly plain paper, the dye in the ink spreads along the fiber in the same manner as a conventional ink after the ink adheres to the recording medium. On the other hand, the cyan pigment in the ink produces an aggregate because the ratio of the cyan pigment and the poor solvent in the ink increases rapidly as the water evaporates immediately after the ink adheres to the recording medium (FIG. 3). (See (a) and (b)).

  The aggregate is rapidly generated as the ratio of the poor solvent in the ink is increased. Therefore, the aggregate is generated as if a bank of a cyan pigment is formed not at the center of the dot but at the outer edge of the dot. As a result, the spread of the dye in the lateral direction can be suppressed (see FIG. 3C).

  With such a mechanism, even when other ink is applied adjacent to the dot (image) formed with the ink according to the present invention, it is compared with the conventional ink containing both a dye and a cyan pigment as a coloring material. We believe that the occurrence of bleeding was suppressed.

  At this time, it is considered that bleeding can be more effectively suppressed by adopting the following configuration. That is, carbon black is used as the color material of the black ink, and the ink according to the present invention described above is used as the cyan ink used in combination therewith. At this time, it is preferable that the black ink contains a poor solvent for carbon black in the ink. Furthermore, it is preferable that the poor solvent for the pigment having a copper phthalocyanine skeleton in the cyan ink of the present invention used together with the black ink is the same as the poor solvent for carbon black in the black ink. This configuration is particularly preferable because bleeding can be suppressed particularly effectively. The reason why bleeding can be suppressed particularly effectively with the above-described configuration is considered as follows. That is, when configured as described above, an aggregate is rapidly formed when the respective color materials come into contact with each other at a location where each ink has permeated on the recording medium or inside the recording medium (depth direction). I guess that is because. In the present invention, particularly when the carbon black to be used is a self-dispersing carbon black in which at least one ionic group is bonded to the surface of the carbon black particles directly or through another atomic group, A preferable effect is obtained. In addition, it is particularly preferable that the poor solvent contained in the cyan ink and the black ink exhibits the maximum Ka value among the Ka values of the water-soluble organic solvents contained in these inks.

Here, the Ka value obtained by the Bristow method will be described. This value is used as a measure for the penetrability of the liquid into the recording medium. Hereinafter, the ink will be described as an example. When the ink permeability is expressed as an ink amount V per 1 m ² , the ink penetration amount V (mL / m ² = μm) after a predetermined time t has elapsed since the ink was ejected is It is shown by Bristow's formula (formula (1)) shown below.
V = V _r + Ka (t−t _w ) ^1/2 formula (1)

Most of the ink immediately after being applied to the recording medium is absorbed by the uneven portion (rough portion of the recording medium surface) on the surface of the recording medium and hardly penetrates into the inside (depth direction) of the recording medium. . The time during this period is the contact time (t _w ), and the amount of ink absorbed in the uneven portion of the recording medium at the contact time is V _r . When the contact time is exceeded after the ink is applied to the recording medium, the time exceeding the contact time, that is, the ink proportional to the 1/2 power of (t−t _w ) Penetrating in the vertical direction) and the amount of penetration increases. Ka is a proportional coefficient for this increase, and is a value corresponding to the penetration rate. The Ka value can be measured using a Bristow method liquid dynamic permeability tester (for example, trade name: Dynamic permeability tester S; manufactured by Toyo Seiki Seisakusho).

  The Ka value according to the Bristow method in the present invention is a value measured using plain paper as a recording medium. Specific examples of the plain paper include, for example, a copying machine using an electrophotographic method, a page printer (laser beam printer), a PB paper for a printer using an ink jet recording method (manufactured by Canon), and a copying method using an electrophotographic method. PPC paper for machine etc. is mentioned. The measurement environment is assumed to be a normal office environment such as a temperature of 20 ° C. to 25 ° C. and a humidity of 40% to 60%.

  Suppressing bleeding, which is one of the effects of the present invention, can be achieved by including a poor solvent for the pigment having a copper phthalocyanine skeleton in the ink. However, in order to obtain the effect of the present invention more efficiently, the following configuration is preferable. That is, the relationship between the content A (mass%) of the pigment having a copper phthalocyanine skeleton and the content B (mass%) of the poor solvent in the ink according to the present invention is the ratio of B to A (B / A). Is preferably 1 or more and 4 or less. In addition, said A and said B show content (mass%) on the basis of the total mass of an ink, respectively. By setting the ratio of B to A (B / A) to 1 or more, a larger aggregate of cyan pigment can be formed in the vicinity of the surface of the recording medium. As a result, it becomes possible to easily suppress the bronzing phenomenon when an image is formed on a glossy recording medium, and further to suppress the bleeding when an image is formed on plain paper. Further, by setting the ratio of B to A (B / A) to 4 or less, an ink having excellent storage stability can be obtained even when the ink is stored for a long time. Specifically, with this configuration, the change rate of the average particle size of the cyan pigment in the ink is small, the ink does not substantially increase in viscosity, and no gel-like sediment is generated in the ink. Etc. can be obtained.

  In addition, in order to obtain more excellent color developability when the ink according to the present invention is applied to plain paper, the following configuration is preferable. In the ink according to the present invention, C: B in the content B (mass%) of the poor solvent and the content C (mass%) of the good solvent may be 10: 5 to 10:30. That is, when C is 10, B is preferably 5 or more and 30 or less (that is, C / B is 0.3 or more and 2 or less). In addition, said B and said C show content (mass%) on the basis of the total mass of an ink, respectively. By setting the ratio of the content of the poor solvent and the good solvent in the ink within the above-mentioned range, when plain paper is used as the recording medium, cyan pigment aggregates are more easily formed near the surface of the recording medium. . As a result, excellent color developability can be obtained. In addition, the definition of the poor solvent and the good solvent in the present invention and the selection method thereof will be described later.

  Furthermore, in order to obtain excellent color developability as described above, the surface tension of the ink according to the present invention is preferably 34.0 mN / m or more, more preferably 38.0 mN / m or more at 25 ° C. . When the surface tension of the ink is less than 34.0 mN / m, the penetration speed of the ink into the recording medium is larger than the aggregation speed of the cyan pigment. For this reason, even if bleeding can be suppressed, sufficiently excellent color developability may not be obtained. The surface tension of the ink according to the present invention is preferably 41.0 mN / m or less. When the surface tension of the ink exceeds 41.0 mN / m, the fixing property of the ink on the recording medium may not be sufficiently obtained, or bleeding may not be sufficiently suppressed. In the present invention, the temperature for measuring the surface tension was 25 ° C., and the surface tension was measured using a Kyowa CBVP-2 surface tension meter (manufactured by Kyowa Kagaku).

<Coloring material content>
The content (mass%) A of the cyan pigment in the ink according to the present invention is 7% or more of the value (A / D × 100%) of the dye content (mass%) D in the ink. It is preferable to make it less than 25%. In addition, said A and said D show content (mass%) on the basis of the total mass of an ink, respectively. By setting the ratio of the cyan pigment and dye content in the ink to 7% or more, a sufficient amount of agglomerates are formed to suppress the lateral spread of the dye in the recording medium. It is because it can suppress more effectively. Also, by setting the ratio of the cyan pigment and dye content in the ink to less than 25%, the difference in gloss between the portion to which the dye is applied and the portion to which the cyan pigment is applied in the glossy recording medium (hereinafter referred to as “gloss”). "Unevenness") can hardly be observed visually.

  The lower limit of the content (% by mass) of the cyan pigment in the ink according to the present invention is preferably 0.2% by mass or more, more preferably 0.7% by mass or more based on the total mass of the ink. Even when the content of the cyan pigment is less than 0.2% by mass, the bronze phenomenon in the glossy recording medium, which is one of the effects of the present invention, can be suppressed. However, when plain paper is used as the recording medium, which is another effect of the present invention, excellent color developability may not be obtained, and the effect of suppressing bleeding may not be sufficiently obtained. This is because when the content of the cyan pigment is less than 0.2% by mass, the phenomenon that the dye in the ink spreads may not be suppressed after the ink is applied to the plain paper. The upper limit of the cyan pigment content (% by mass) needs to be less than 1% by mass based on the total mass of the ink, as described above. Further, the lower limit of the content (% by mass) of the dye in the ink according to the present invention is preferably 2.0% by mass or more, more preferably 3.0% by mass or more based on the total mass of the ink. This is because when the dye content is less than 2.0% by mass, excellent color developability may not be obtained. In addition, the upper limit of the content (% by mass) of the dye in the ink according to the present invention is preferably 5.0% by mass or less, more preferably 3.7% by mass or less, based on the total mass of the ink. If the dye content exceeds 5.0% by mass, ink reliability may not be obtained.

<Definition of poor solvent and good solvent>
The ink according to the present invention contains a pigment having a copper phthalocyanine skeleton dispersed in an aqueous medium. As the pigment having a copper phthalocyanine skeleton, the following can be used. For example, a self-dispersing pigment in which at least one ionic group is bonded to the surface of the pigment particle directly or through another atomic group, a resin dispersion type in which it is dispersed in an aqueous medium by a dispersant, a surfactant or the like And pigments. In the present invention, a water-soluble organic solvent capable of stably maintaining the dispersion state of the pigment dispersion having a copper phthalocyanine skeleton present in the ink in the state as described above can be used as a good solvent and the dispersion state can be maintained stably. An insoluble water-soluble organic solvent is defined as a poor solvent.

More specifically, as described below, it is determined whether the water-soluble organic solvent used is a poor solvent or a good solvent for the pigment dispersion having a copper phthalocyanine skeleton. First, the following two types of dispersions are prepared: a dispersion X of a pigment dispersion having a copper phthalocyanine skeleton, and an aqueous dispersion Y of the pigment dispersion, each containing a water-soluble organic solvent to be judged. To do.
Dispersion X: 50% by mass of a water-soluble organic solvent as a determination target, a pigment having a copper phthalocyanine skeleton, or a pigment having the copper phthalocyanine skeleton and a total amount of substances contributing to the dispersion are 5% by mass, and water is 45% by mass % Of the composition dispersion.
Water dispersion Y: An aqueous dispersion having a composition in which the total amount of the pigment having a copper phthalocyanine skeleton, or the pigment having the copper phthalocyanine skeleton and the substance contributing to the dispersion is 5% by mass and water is 95% by mass.

  Next, the average particle diameter of the pigment having a copper phthalocyanine skeleton after the dispersion X is stored at 60 ° C. for 48 hours is measured. Similarly, the average particle diameter of the pigment having a copper phthalocyanine skeleton in the aqueous dispersion Y is measured. And let the average particle diameter of the pigment which has each copper phthalocyanine frame | skeleton of the dispersion liquid X and the water dispersion liquid Y be a particle size (A) and a particle size (B). At this time, when the particle size (A) is larger than the particle size (B), the water-soluble organic solvent is a poor solvent, and the particle size (A) is equal to or smaller than the particle size (B). Determined as solvent.

  In the above description, the method for determining the poor solvent and the good solvent for the pigment dispersion having a copper phthalocyanine skeleton has been described. However, when the pigment is carbon black, the poor solvent and the good solvent can be determined in the same manner as described above. Judgment can be made. Specific examples of the water-soluble organic solvent that is a poor solvent for the pigment having a copper phthalocyanine skeleton used in the present invention include polyethylene glycol 1000 (polyethylene glycol having an average molecular weight of 1,000), 2-pyrrolidone, 1,5-pentanediol, and the like. Is mentioned. Specific examples of the water-soluble organic solvent that is a good solvent for the pigment having a copper phthalocyanine skeleton include glycerin and ethylene glycol. Of course, the poor solvent and the good solvent that can be used in the present invention are not limited to these.

<Inkjet ink>
Next, each component constituting the ink according to the present invention will be described.
[Color material]
The ink according to the present invention needs to contain a pigment having a copper phthalocyanine skeleton as a coloring material. The bronze phenomenon of an image formed using an ink containing a pigment having a copper phthalocyanine skeleton as a color material is very remarkable as compared with the case of using an ink containing another color material. For this reason, the present invention has an object to solve the above-mentioned problem of bronze phenomenon. Examples of the pigment having a copper phthalocyanine skeleton that can be used in the ink according to the present invention include the following. Specifically, for example, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 16 or the like. Among the pigments having a copper phthalocyanine skeleton described above, in the present invention, C.I. I. It is particularly preferable to use Pigment Blue 15: 3.

  Furthermore, the ink according to the present invention needs to contain a specific dye in addition to the above-described pigment having a copper phthalocyanine skeleton. Here, the specific dye is C.I. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9. The reason why the effects of the present invention can be obtained by using these dyes is not clear. However, the present inventors presume as follows. The above-mentioned dye has characteristics such as excellent color developability. For this reason, even in the case where the content of the cyan pigment is small as in the present invention, in addition to being able to form an image with high color developability, by using it in combination with a poor solvent for a pigment having a copper phthalocyanine skeleton, It is thought that a synergistic effect was exhibited.

(Pigment having copper phthalocyanine skeleton)
The pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention can be used regardless of the dispersion method. For example, a resin dispersion type pigment (resin dispersion type pigment) dispersed using a dispersant or a surfactant dispersion type pigment dispersed by a surfactant can be used. In addition, a self-dispersing pigment (self-dispersing pigment) that can be dispersed without introducing a ionic group on the surface of the pigment particles and using a dispersant or the like can be used. Furthermore, microcapsule type pigments with improved dispersibility by coating the surface of pigment particles with organic polymers, and organic groups containing polymers on the surface of pigment particles were modified by chemical bonding. Polymer-bonded self-dispersing pigments can be used. Of course, in the present invention, the above-mentioned pigments having different dispersion methods can be used in combination. Hereinafter, the pigment that can be used in the present invention will be described.

[Resin dispersion type pigment]
As described above, a resin dispersion type pigment can be used for the pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention. In this case, it is preferable to disperse the hydrophobic pigment in the aqueous medium using a dispersant, a surfactant or the like. The dispersant or surfactant used in this case is not particularly limited, and the following can be used.

As the surfactant, an anionic surfactant or a nonionic surfactant can be used.
The following can be used as an anionic surfactant. Specifically, for example, fatty acid salt, alkyl sulfate ester salt, alkylbenzene sulfonate, alkyl naphthalene sulfonate,
Examples thereof include dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl sulfate ester salt, and substituted derivatives thereof.
The following can be used for the nonionic surfactant. Specifically, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester,
Examples include sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethyleneoxypropylene block polymer, or substituted derivatives thereof.

The following can be used for a dispersing agent. Specifically, for example, styrene or a derivative thereof, vinyl naphthalene or a derivative thereof, an aliphatic alcohol ester of α, β-ethylenically unsaturated carboxylic acid,
Acrylic acid or derivatives thereof, maleic acid or derivatives thereof, itaconic acid or derivatives thereof, fumaric acid or derivatives thereof,
Block copolymer composed of at least two monomers selected from vinyl acetate, vinyl alcohol, vinyl pyrrolidone, acrylamide, or derivatives thereof (of which at least one is a hydrophilic monomer), random copolymer Coalesced and graft copolymers,
Or these salts etc. are mentioned. Furthermore, a block copolymer and a random copolymer can be used in combination.

[Microcapsule type pigment]
For the pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention, as described above, a microcapsule type pigment whose dispersibility is improved by coating the surface of the pigment particle with an organic polymer or the like is used. be able to.

(Self-dispersing pigment)
As described above, the pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention has a self-dispersion type in which an ionic group is introduced on the surface of the pigment particle and can be dispersed without using a dispersant or the like. Pigments can be used. Self-dispersing pigments include those in which an ionic group is bonded directly or via other atomic groups to the surface of pigment particles. For example, ionic groups introduced into the surface of the pigment particles, -COOM, -SO ₃ M, and -PO ₃ H (M) ₂ (where M in the formula, a hydrogen atom, an alkali metal, ammonium or organic ammonium) It is preferable to be one selected from the group consisting of Furthermore, the other atomic group is preferably an alkylene group having 1 to 12 carbon atoms, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted naphthylene group. In addition, the surface oxidation treatment obtained by oxidizing the pigment with sodium hypochlorite or ozone treatment in water, the method of modifying the pigment particle surface by wet oxidation with an oxidizing agent after ozone treatment, etc. A type of self-dispersing pigment can be used.

[Polymer-bonded self-dispersing pigment]
As described above, the pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention has a polymer-bonded self-dispersion modified by chemically bonding an organic group containing a polymer to the surface of the pigment particle. Type pigments can be used. A polymer-bonded self-dispersing pigment is obtained by reacting a functional group chemically bonded to the surface of pigment particles directly or through another atomic group with a copolymer of an ionic monomer and a hydrophobic monomer. It is preferable to use what is contained. This can appropriately change the copolymerization ratio of the ionic monomer and the hydrophobic monomer, which are the materials of the copolymer used for modifying the surface, and the ionicity of the modified pigment can be changed arbitrarily. This is because it can be adjusted. Moreover, since the kind of ionic monomer and hydrophobic monomer and the combination of both can be arbitrarily changed, various characteristics can be imparted to the surface of the pigment particles.

[Aqueous medium]
As described above, the ink according to the present invention includes a pigment having a specific content of a copper phthalocyanine skeleton, a specific dye, and a poor solvent for the pigment. As the other ink components, any of those used in conventional ink-jet inks can be used. For example, as the aqueous medium for dissolving or dispersing the above-described pigments and dyes contained in the ink, any of those listed below can be used as long as it contains a poor solvent for the pigment. .

The aqueous medium is preferably water or a mixed medium of water-soluble organic solvent and water. The content (% by mass) of the water-soluble organic solvent in the ink according to the present invention is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. Specifically, for example, the following water-soluble organic solvents can be used. C1-C4 alkanols such as ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol and the like;
Carboxylic acid amides such as N, N-dimethylformamide or 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;
Glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol,
1,2- or 1,3-propylene glycol, 1,2- or 1,4-butylene glycol, polyethylene glycol, 1,3-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1, 6-hexanediol,
Dithioglycol, 2-methyl-1,3-propanediol, 1,2,6-hexanetriol,
Polyhydric alcohols such as acetylene glycol derivatives and trimethylolpropane;
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;
Heterocycles such as 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylmorpholine;
Sulfur-containing compounds such as dimethyl sulfoxide, urea and urea derivatives.

  Moreover, it is preferable to use deionized water (ion exchange water) as the water. The water content (% by mass) in the ink according to the present invention has an appropriate viscosity for stably ejecting the ink, and in order to suppress clogging at the nozzle tip, It is preferable to set it as 50.0 mass% or more and 90.0 mass% or less as a reference | standard.

[Additive]
In addition to the components described above, the ink according to the present invention includes a surfactant, a pH adjuster, a chelating agent, a rust preventive agent, an antiseptic agent, an antifungal agent, an ultraviolet absorber, a viscosity modifier, an antifoaming agent, and Various additives such as a water-soluble polymer may be contained.

Examples of the surfactant include an anionic surfactant, an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant.
Specifically, the following can be used for an anionic surfactant, for example.
Alkyl sulfocarboxylate, α-olefin sulfonate, polyoxyethylene alkyl ether acetate, N-acyl amino acid or salt thereof, N-acylmethyl taurate,
Alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester,
Alkylphenol phosphate, alkyl phosphate, alkylallylsulfone hydrochloride,
Diethyl sulfosuccinate, diethylhexyl sulfosuccinate dioctyl sulfosuccinate and the like.

Specifically, for example, the following can be used as the cationic surfactant.
Examples include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives. Amphoteric surfactants include lauryldimethylaminoacetic acid betaine,
2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives and the like.

Specific examples of nonionic surfactants include the following.
Polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene lauryl ether,
Ethers such as polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, polyoxyallylalkyl alkyl ether,
Polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate,
Ester series such as sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate,
2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol And the like (for example, acetylenol EH manufactured by Kawaken Fine Chemicals, Surfynol 104, 82, 465, Olphine STG manufactured by Nissin Chemical), and the like.

<Inkjet ink manufacturing method>
The ink according to the present invention may be any ink that satisfies the following structural requirements essential in the present invention. That is, the coloring material needs to be a specific dye and a pigment having a copper phthalocyanine skeleton. Specific dyes include C.I. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9. Further, it is necessary that the water-soluble organic solvent contains a poor solvent for the cyan pigment, and the content of the cyan pigment in the ink is less than 1% by mass. The ink according to the present invention is not particularly limited as long as it satisfies the above-described constituent requirements, and the production method and the embodiment thereof are not particularly limited.

  The ink-jet ink of the present invention can be produced according to a conventional method using each of the components described above. As described below, the ink-jet ink of the present invention recycles the ink remaining in the ink cartridge, so that the ink according to the present invention is economically and environmentally preferable. It can also be obtained by a manufacturing method.

  Specifically, it is a method for producing an ink having a step of injecting an ink containing a specific dye into an ink cartridge containing a pigment having a copper phthalocyanine skeleton and an ink containing a poor solvent for the pigment. . The specific dye is C.I. I. Direct Blue 199, C.I. I. Direct Blue 86 and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9.

  As described above, the pigment having a copper phthalocyanine skeleton contained in the ink according to the present invention and the poor solvent for the pigment can sufficiently obtain the effects of the present invention even when the content thereof is small. Can do. For this reason, the ink concerning this invention can be manufactured also by embodiment as mentioned above. By producing ink by the above-described method, it is possible to reuse an ink cartridge containing a pigment having a copper phthalocyanine skeleton having excellent performance and a poor solvent for the pigment, thereby reducing costs. Become. Furthermore, according to the above-described method, it is possible to further obtain an effect of facilitating the filling of the ink into the ink cartridge that once contains the ink and the ink cartridge having the ink storage portion that stores the ink.

<Black ink>
The ink according to the present invention is particularly preferably a cyan ink used together with a black ink containing water, carbon black, and a water-soluble organic solvent. By adopting such a configuration, it is considered that bleeding can be more effectively suppressed. Hereinafter, each component constituting the black ink will be described.

[Color material]
Carbon black contained in the black ink can be used regardless of the dispersion method. Similar to the method for dispersing the pigment having a copper phthalocyanine skeleton, for example, a resin dispersion type carbon black (resin dispersion type carbon black) dispersed using a dispersant, or a surfactant dispersion type dispersed by a surfactant. Carbon black can be used. Also, self-dispersing carbon black (self-dispersing carbon black) that can be dispersed without introducing a ionic group on the surface of the carbon black particles and using a dispersant or the like can be used. Further, microcapsule type carbon black whose dispersibility is improved by coating the surface of carbon black particles with organic polymers can be used. Furthermore, polymer-bonded self-dispersing carbon black modified by chemically bonding an organic group containing a polymer to the surface of the carbon black particles can be used. Of course, in the present invention, carbon blacks having different dispersion methods mentioned above can be used in combination.

As the carbon black that can be used in the black ink used together with the ink according to the present invention, for example, carbon black such as furnace black, lamp black, acetylene black, and channel black can be used. Specifically, the following commercially available products can be used.
Raven: 1170, 1190 ULTRA-II, 1200, 1250, 1255, 1500, 2000, 3500, 5000ULTRA, 5250, 5750, 7000 (above Colombia);
Black Pearls L;
Regal: 330R, 400R, 660R;
Mogul L;
Monarch: 700, 800, 880, 900, 1000, 1100, 1300, 1400, 2000;
Vulcan XC-72R (above, manufactured by Cabot).
Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170;
Printex: 35, U, V, 140U, 140V;
Special Black: 4, 4A, 5, 6 (above, manufactured by Degussa).
No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300;
MCF-88, MA600, MA7, MA8, MA100 (above, manufactured by Mitsubishi Chemical).

  Carbon black newly prepared for the present invention can also be used. However, the present invention is not limited to these, and any conventionally known carbon black can be used. Magnetic fine particles such as magnetite and ferrite, titanium black and the like can be used in combination with carbon black. The carbon black content (% by mass) in the black ink is 0.1% by mass or more and 15.0% by mass or less, and further 1.0% by mass or more and 10.0% by mass or less, based on the total mass of the black ink. It is preferable that

[Aqueous medium]
As the aqueous medium used for the black ink used in the present invention, it is preferable to use water or a mixed medium of a water-soluble organic solvent and water. And it is preferable that this black ink contains the poor solvent with respect to carbon black demonstrated previously. In this case, the carbon black includes a dispersion such as a resin dispersion type carbon black and a self dispersion type carbon black. By setting it as the above structures, bleeding can be suppressed more effectively. It is particularly preferable that the poor solvent for the pigment having a copper phthalocyanine skeleton in the cyan ink of the present invention used together with the black ink is a poor solvent for the carbon black in the black ink, since bleeding can be suppressed particularly effectively. The component constituting the aqueous medium in the black ink used together with the ink according to the present invention is not particularly limited as long as it satisfies the above-described preferred structure, and is the same as the aqueous medium contained in the ink described above. Can be used.

[Additive]
In addition to the components described above, the black ink includes surfactants, pH adjusters, chelating agents, rust preventives, antiseptics, antifungal agents, ultraviolet absorbers, viscosity modifiers, antifoaming agents, and water solubility. You may contain various additives, such as a polymer. As such additives, the same additives as those used in the ink of the present invention described above can be used.

<Inkjet recording method>
The ink according to the present invention provides good results particularly when used in an ink jet recording method in which ink is ejected in accordance with a recording signal and recording is performed on a recording medium. A preferable inkjet recording method in this case includes a method of recording on a recording medium by applying thermal energy to the ink.

<Ink cartridge>
Examples of the ink cartridge suitable for performing recording using the ink according to the present invention include an ink cartridge having an ink containing portion for containing these inks. Specific examples of ink cartridges suitable for recording using the ink according to the present invention are shown below.

  FIG. 1 is a schematic explanatory view and a cross-sectional view of an ink cartridge that can be suitably used for recording using the ink according to the present invention. As shown in FIG. 1, the ink cartridge communicates with the atmosphere via the atmosphere communication port 112 at the upper portion and communicates with the ink supply port at the lower portion. The interior of the ink cartridge is partitioned by a partition wall 138 into a negative pressure generating member storage chamber 134 that stores a negative pressure generating member and a substantially sealed liquid storage chamber 136 that stores liquid ink. The negative pressure generating member storage chamber 134 and the liquid storage chamber 136 are connected to the communication hole 140 formed in the partition wall 138 near the bottom of the ink cartridge and the atmosphere for promoting the introduction of the atmosphere into the liquid storage chamber during the liquid supply operation. It communicates only through the introduction groove (atmosphere introduction path) 150. A plurality of ribs are integrally formed on the upper wall of the ink cartridge constituting the negative pressure generating member storage chamber 134 so as to protrude inside, and the negative pressure stored in the negative pressure generating member storage chamber 134 in a compressed state. It is in contact with the generating member. By this rib, an air buffer chamber is formed between the upper wall and the upper surface of the negative pressure generating member. Further, the ink supply cylinder provided with the liquid supply port 114 is provided with a pressure contact body 146 having a higher capillary force and a higher physical strength than the negative pressure generating member, and is in pressure contact with the negative pressure generating member.

  In the illustrated example, in the negative pressure generating member storage chamber, two of the first negative pressure generating member 132B and the second negative pressure generating member 132A, which are made of olefin resin fibers such as polyethylene, are used as the negative pressure generating member. Two capillary force generating negative pressure generating members are accommodated. Reference numeral 132C denotes a boundary layer between the two negative pressure generating members, and an intersecting portion of the boundary layer 132C with the partition wall 138 has an air introduction groove (atmosphere introduction path) in the posture when the ink cartridge is used with the communication portion downward. ) It exists above the upper end of 150. Further, the ink accommodated in the negative pressure generating member exists above the boundary layer 132C as indicated by the ink level L.

  Here, the boundary layer between the first negative pressure generating member and the second negative pressure generating member is in pressure contact, and the vicinity of the boundary layer of the negative pressure generating member has a higher compressibility than other parts, and the capillary force Is in a strong state. That is, assuming that the capillary force of the first negative pressure generating member is P1, the capillary force of the second negative pressure generating member is P2, and the capillary force of the interface between the negative pressure generating members is PS, P2 <P1 <PS. It has become.

  FIG. 2 is a schematic explanatory view of another ink cartridge suitable for recording using the ink according to the present invention, and is a cross-sectional view. As shown in FIG. 2, the ink cartridge includes a container 41 that stores ink of three colors, yellow (Y), magenta (M), and cyan (C), and a lid member 42 that covers the container 41.

  The interior of the container 41 is partitioned into three spaces having substantially the same capacity by two partition plates 411 and 412 arranged in parallel to each other in order to store three colors of ink. These three spaces are arranged along the insertion direction of the color ink cartridge when the color ink cartridge is mounted in the ink cartridge holder. In each of these spaces, an ink absorber 44Y that absorbs and holds yellow ink, an ink absorber 44M that absorbs and holds magenta ink, and an ink absorber 44C that absorbs and holds cyan ink. Is stored. Further, the ink stored in the ink absorber 44Y, the ink absorber 44M, and the ink absorber 44C, which are negative pressure generating members, reaches the top of each ink absorber as indicated by the ink level L. Existing.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited by the following examples as long as the gist thereof is not exceeded. In the following description, “parts” and “%” are based on mass unless otherwise specified.

<Evaluation of ink>
Here, the ink which is one embodiment of the present invention was prepared by the following procedure, and the obtained ink was evaluated as follows.

[Evaluation of bronze phenomenon, uneven gloss, and storage stability]
(Preparation of cyan pigment dispersion)
10 parts of a pigment (CI Pigment Blue 15: 3), 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. Thereafter, coarse particles were removed by centrifugation. Further, the mixture was filtered under pressure with a micro filter (manufactured by Fuji Film) having a pore size of 3.0 μm to prepare a cyan pigment dispersion. Thereafter, the pigment concentration was adjusted to 10% with water to obtain a cyan pigment dispersion. As the dispersant, an aqueous solution obtained by neutralizing a styrene-acrylic acid copolymer having an acid value of 200 and a weight average molecular weight of 10,000 with a 10% aqueous sodium hydroxide solution was used.

(Determination of poor and good solvents for each water-soluble organic solvent)
In order to select a water-soluble organic solvent that acts as a poor solvent and a good solvent for the cyan pigment dispersion obtained above, the following experiment was conducted. First, a 10% solids concentration aqueous solution of the cyan pigment dispersion obtained above was prepared, and using this and each water-soluble organic solvent, a dispersion for determining poor and good solvents at the following blending ratios: X and an aqueous dispersion Y for determination were prepared.

[Dispersion liquid X for determination]
-50 parts of cyan pigment dispersion-50 parts of each water-soluble organic solvent listed in Table 1 [Water dispersion Y for determination]
・ Cyan pigment dispersion 50 parts ・ Pure water 50 parts

  Next, 10 g of each of the determination dispersion X and the determination water dispersion Y prepared as described above were put in a transparent glass lidded sample bottle, capped, and then sufficiently stirred. The mixture was left at 48 ° C. for 48 hours. Thereafter, the average particle size of the pigment in the dispersion was measured using a concentrated dispersion particle size analyzer (trade name: FPAR-1000; manufactured by Otsuka Electronics Co., Ltd.) using the dispersion as a measurement sample. A water-soluble organic solvent in which the average particle diameter of the pigment in the determination dispersion X and the determination aqueous dispersion Y after storage at 60 ° C. for 48 hours is larger than that of the determination aqueous dispersion Y is poor. The solvent was determined. A water-soluble organic solvent having an average particle size of the determination dispersion X after storage at 60 ° C. for 48 hours equal to or less than that of the determination aqueous dispersion Y was determined as a good solvent.

  By measuring the average particle size as described above, for the two types of water-soluble organic solvents shown in Table 1, the poor solvent and the good solvent were compared with the pigment dispersion in the cyan pigment dispersion prepared earlier. Judgment was made as to which case. The evaluation results are shown in Table 1. The results in Table 1 were shown as ◯ when judged as a good solvent and as x when judged as a poor solvent.

(Measurement of Ka value of water-soluble organic solvent)
First, in measuring the Ka value of each water-soluble organic solvent listed in Table 1, dye aqueous solutions each having a composition shown below and having a dye content of 0.5% were prepared. The reason why such an aqueous dye solution is used is that it is visualized by coloring a colorless and transparent aqueous solution to facilitate measurement of the Ka value.
・ C. I. Direct Blue 199 0.5 part, Pure water 99.5 parts

Next, a 20% aqueous solution of a colored water-soluble organic solvent having the following composition was prepared from the 0.5% dye aqueous solution and each water-soluble organic solvent to be measured.
80 parts of the above 0.5% dye aqueous solution 20 parts of the water-soluble organic solvent listed in Table 1

  Using the 20% aqueous solution of each water-soluble organic solvent prepared above as a sample for measurement, using a dynamic permeability test apparatus (trade name: dynamic permeability test apparatus S; manufactured by Toyo Seiki Seisakusho), the Bristow method The Ka value of a 20% aqueous solution of each water-soluble organic solvent was determined. Table 1 shows the measurement results of the Ka value in a 20% aqueous solution of each water-soluble organic solvent that can be used in the ink, measured as described above.

(Preparation of ink)
After mixing each component shown in Table 2 and Table 3 and stirring sufficiently, pressure filtration was performed with a micro filter (manufactured by Fuji Film) having a pore size of 3.0 μm, and Reference Examples 1 to 3, 6, and 7 were carried out. Inks of Examples 4, 5, 8 to 11 and Comparative Examples 1 to 7 were prepared. Moreover, the Yi ink obtained above, using a Kyowa CBVP-2 formula surface tension meter (Kyowa Science), it was measured surface tension of the ink at 25 ° C.. The measured surface tensions of the inks are shown in Tables 2 and 3. In Tables 2 and 3, the pigment content A (%), the poor solvent content B (%), the good solvent content C (%), and the dye content D ( %) And B / A, C / B, and A / D × 100 (%).

(Preparation of recorded material)
Using the inks of Reference Examples 1 to 3, 6, 7, Examples 4 , 5 , 8 to 11 and Comparative Examples 1 to 5 and 7, recorded matter was prepared. An ink jet recording apparatus (trade name: PIXUS 950i; manufactured by Canon Inc.) that discharges ink by the action of thermal energy was used for the production of recorded matter. Specifically, the ink cartridge having the configuration of FIG. 1 was filled with each of the inks obtained above, and the ink cartridge was mounted on the ink jet recording apparatus to form an image. And using each ink, the recorded matter which formed the solid image of 10 cm x 10 cm was produced on professional photo paper PR-101 (product made from Canon). The printer driver selected the Pro Photo Paper mode. The setting conditions for the Pro Photo Paper mode are as follows.
-Paper type: Pro photo paper-Print quality: Beautiful-Color adjustment: Automatic

(Bronze phenomenon)
Place each recorded matter obtained above on a desk irradiated with a white fluorescent lamp, and change the line of sight of the recorded matter to visually check the recorded matter from various angles to confirm the occurrence of the bronze phenomenon. Evaluation was performed. The evaluation criteria for the bronze phenomenon are as follows. The evaluation results are shown in Table 4.

A: Even when the angle was changed, no change in the color of reflected light on the recorded material was observed.
B: Although the change in the color of the reflected light in the recorded material was confirmed by changing the angle, the level was inconspicuous compared with the change in the color of the reflected light in the recorded material of the comparative example.
C: The change in the color of the reflected light in the recorded matter was confirmed by changing the angle at the same level as the change in the color of the reflected light in the recorded matter of the comparative example.

上記の結果、参考例６〜７、実施例８のインクを使用した場合の記録物は、ブロンズ現象発生の評価において何れもＢと判定されたが、実施例８のインクを使用した場合は、参考例６及び７のインクを使用した場合よりも若干劣っていた。

As a result of the above, the recorded materials when the inks of Reference Examples 6 to 7 and Example 8 were used were all determined to be B in the evaluation of the occurrence of bronze phenomenon, but when the ink of Example 8 was used, It was slightly inferior to the case where the inks of Reference Examples 6 and 7 were used.

(Gloss unevenness)
The recorded matter obtained above was visually observed and the occurrence of uneven gloss was confirmed and evaluated. As a result, in Reference Examples 6 and 7, in which the content ratio (A / D × 100%) of the pigment and the dye in the ink was high, the occurrence of uneven gloss was observed as compared with the recorded matter prepared with other inks. .

(Storage stability)
Each of the inks of Reference Examples 1 to 3, 6, 7 and Examples 4, 5, 8 to 11 prepared previously was put in a shot bottle, sealed, and stored in an oven at 60 ° C. for 2 weeks. The average particle diameter of the pigment and the viscosity of the ink were measured before and after storage at 60 ° C., respectively, and the change rate of the average particle diameter and the change rate of the viscosity were obtained, and evaluation was performed based on the obtained change rates. The evaluation criteria for storage stability are as follows. The evaluation results are shown in Table 5.
A: The change rate of the average particle diameter of the pigment or the change rate of the viscosity of the ink is 5% or less before and after storage at 60 ° C.
B: The change rate of the average particle diameter of the pigment or the change rate of the viscosity of the ink is more than 5% and 10% or less before and after storage at 60 ° C.
C: After storage at 60 ° C., the ink has changed to a gel state, the upper part of the ink has changed to transparent, or the ink is clearly thickened.

[Evaluation of color development and bleeding of images formed on plain paper]
Previously prepared 1～3,6,7, Example 4, 5, 8 to 11, and, using each ink, the black ink further illustrated in the following Comparative Examples 1-4 and 6-7, the following evaluation Went.

(Preparation of black pigment dispersion 1)
10 parts of carbon black having a specific surface area of 210 m ² / g and DBP oil absorption of 74 ml / 100 g, 20 parts of a dispersant, and 70 parts of ion-exchanged water were mixed and dispersed for 1 hour using a sand grinder. Thereafter, coarse particles were removed by centrifugation. Further, the mixture was filtered under pressure through a micro filter (manufactured by Fuji Film) having a pore size of 3.0 μm to prepare a black pigment dispersion 1. Then, it adjusted with water so that a pigment concentration might be 10%, and the black pigment dispersion liquid 1 was obtained. As the dispersant, an aqueous solution obtained by neutralizing a styrene-acrylic acid copolymer having an acid value of 200 and a weight average molecular weight of 10,000 with a 10% aqueous sodium hydroxide solution was used.

(Preparation of black pigment dispersion 2)
To a solution prepared by dissolving 5 g of concentrated hydrochloric acid in 5.5 g of water, 1.5 g of 4-aminophthalic acid was added while being cooled to 5 ° C. Next, the container containing the solution was placed in an ice bath and the solution was stirred to keep the solution constantly at 10 ° C. or lower, and 1.8 g of sodium nitrite was dissolved in 9 g of water at 5 ° C. The solution was added. After the solution was further stirred for 15 minutes, 6 g of carbon black having a specific surface area of 220 m ² / g and a DBP oil absorption of 105 mL / 100 g was added with stirring. Thereafter, the mixture was further stirred for 15 minutes. The obtained slurry was filtered with a filter paper (trade name: Standard filter paper No. 2; manufactured by Advantech), and then the particles were sufficiently washed with water and dried in an oven at 110 ° C. to prepare self-dispersing carbon black. Thereafter, the black pigment dispersion 2 was obtained by adjusting with water so that the carbon black concentration was 10%.

(Determination of poor and good solvents for each water-soluble organic solvent)
A water-soluble organic solvent that acts as a poor solvent and a good solvent for the black pigment dispersions 1 and 2 obtained above by the same method as the determination of the poor solvent and the good solvent of the water-soluble organic solvent for the cyan pigment dispersion. An experiment was conducted to select With respect to the two types of water-soluble organic solvents shown in Table 6, it was determined whether a poor solvent or a good solvent corresponds to the pigment dispersion in the black pigment dispersion. The evaluation results are shown in Table 6. The results in Table 6 were shown as ◯ when judged as a good solvent and x when judged as a poor solvent.

(Preparation of black ink)
The components shown in Table 7 below were mixed and sufficiently stirred, and then pressure filtration was performed with a micro filter (manufactured by Fuji Film) having a pore size of 3.0 μm to prepare black inks 1 and 2.

(Preparation of recorded material)
An ink jet recording apparatus (trade name: PIXUS 950i; manufactured by Canon Inc.) that discharges ink by the action of thermal energy was used for the production of recorded matter. Specifically, the ink cartridge having the configuration of FIG. 1 was filled with each of the inks obtained above, and the ink cartridge was mounted on the ink jet recording apparatus to form an image. And each of the inks of Reference Examples 1 to 3, 6, 7 and Examples 4, 5 , 8 to 11 and Comparative Examples 1 to 4 and 6 to 7, and the black ink 1 were used, and the following four types. A recorded material in which a solid image of 2 cm × 2 cm in which the cyan ink and the black ink 1 were adjacent to each other was prepared.

The printer driver selected the default mode. The default mode setting conditions are as follows.
-Paper type: Plain paper-Print quality: Standard-Color adjustment: Automatic

As the recording medium, the following four types of copy paper (plain paper) were used.
・ PPC paper PB (Canon)
・ PPC paper 4024 (Xerox)
・ PPC paper prober bond (manufactured by Fox River)
・ Canon PPC paper (made by Neuzidra)

(Color development and bleeding)
Immediately after producing the recorded matter, the degree of bleeding in the portion where the image formed with the black ink 1 and the image formed with the inks of the examples and the reference examples were observed was visually observed. Similarly, the degree of bleeding in the portion where the image formed with the black ink 1 and the image formed with the ink of the comparative example are adjacent to each other is visually observed and compared with the recorded materials of the examples and the reference examples. Evaluation was performed. Further, one day after producing the recorded matter, the optical density in the cyan image was measured using Macbeth RD915 (manufactured by Macbeth). The evaluation criteria for color development and bleeding are as follows. The evaluation results are shown in Table 8. The evaluation results in Table 8 were common to any recording medium used.

A: Both the color developability and the suppression of bleeding are clearly superior to the image formed with the ink of the comparative example.
B: Compared with the image formed with the ink of the comparative example, either color development or bleeding suppression is superior.
C: There is no difference in color development and suppression of bleeding compared to an image formed with the ink of the comparative example.

As is clear from Table 8, Reference Examples 1 to 3, 6, 7 and Examples 4, 5, 8 to 11 are all Comparative Examples 1 to 4 that do not contain a poor solvent for the pigment, and the coloring material is only a dye. As compared with Comparative Example 6 and Comparative Example 7 in which the color material is only a pigment, it was found that at least one effect of suppressing color development or bleeding was obtained. Note that Reference Example 6 was superior to Examples 4 and 5 in both color development and suppression of bleeding. Further, in Reference Example 7 and Examples 8 to 9, since the content of the dye in the ink was larger than that in the comparative example, the color developability was good. However, Example 8 as compared to Reference Example 7 and Example 9, the proportion of the content B of the poor solvent to the content A of the pigment is small, color developing property and bleeding of inhibition was slightly inferior.

By using the black ink 2 instead of the black ink 1, a recorded matter on which a 2 cm × 2 cm solid image in which the cyan ink and the black ink 2 of Reference Example 1 were adjacent to each other was produced. Immediately after making the recording material, the image formed by the black ink 2 to the degree of bleeding at a portion where the image formed of the ink of Reference 1 adjacent and was visually observed, and the cyan ink of the above Reference Example 1 Evaluation was performed in comparison with the recorded material prepared with the black ink 1. As a result, the recorded matter produced using the black ink 2 was ranked B according to the same evaluation criteria as described above. However, as compared with the recorded matter produced using the black ink 1, the result of slightly suppressing bleeding was obtained.

<Evaluation of inkjet ink production method>
Here, the ink obtained by the ink jet ink manufacturing method according to another embodiment of the present invention was evaluated.

  Each component shown in Table 9 below was mixed and sufficiently stirred, and then pressure filtration was performed with a microfilter (manufactured by Fuji Film) having a pore size of 3.0 μm to prepare ink A. This ink A contains a copper phthalocyanine pigment and a poor solvent for the copper phthalocyanine pigment.

  14.5 g of ink A prepared according to the formulation shown in Table 9 was injected into the ink cartridge having the configuration shown in FIG. Thereafter, 12.5 g of ink was discharged from the ink cartridge. Thereafter, the ink cartridges were prepared for the previously prepared inks of Comparative Examples 1 to 3, respectively, and 10.0 g of each of them was filled to prepare inks of Examples 12 to 14. When these inks were extracted from the ink cartridge and the composition was analyzed, the compositions shown in Table 10 below were found. Further, for the inks of Examples 12 to 14 obtained above, the surface tension of the ink at 25 ° C. was measured using a Kyowa CBVP-2 type surface tension meter (Kyowa Science). Table 10 shows the measured surface tension of the ink.

(Preparation of recorded material)
A recorded matter was produced using each of the inks of Examples 12-14. An ink jet recording apparatus (trade name: PIXUS 950i; manufactured by Canon Inc.) that discharges ink by the action of thermal energy was used for the production of recorded matter. Specifically, the ink cartridge obtained above was mounted on the ink jet recording apparatus to form an image. And the recorded matter which formed the solid image of 10 cm x 10 cm was produced on professional photo paper PR-101 (product made from Canon) using each ink of Examples 12-14. The printer driver selected the Pro Photo Paper mode. The setting conditions for the Pro Photo Paper mode are as follows.
-Paper type: Pro photo paper-Print quality: Beautiful-Color adjustment: Automatic

(Bronze phenomenon)
The recorded matter obtained above is placed on a desk irradiated with a white fluorescent lamp, and by changing the line of sight of the recorded matter, the recorded matter is visually observed from various angles, and the occurrence of bronzing is confirmed and evaluated. Went. The evaluation criteria for the bronze phenomenon are as follows. The evaluation results are shown in Table 11. In addition, the comparative example in the following evaluation criteria is the ink of Comparative Examples 1-5 and 7.

A: Even when the angle was changed, no change in the color of reflected light on the recorded material was observed.
B: Although the change in the color of the reflected light in the recorded material was confirmed by changing the angle, the level was inconspicuous compared with the change in the color of the reflected light in the recorded material of the comparative example.
C: The change in the color of the reflected light in the recorded matter was confirmed by changing the angle at the same level as the change in the color of the reflected light in the recorded matter of the comparative example.

  An application example of the present invention is an ink-jet ink that can effectively use an ink cartridge that contains a pigment having a copper phthalocyanine skeleton as a colorant and a poor solvent for the pigment. A manufacturing method is mentioned. According to this manufacturing method, an ink cartridge that contains useful ink can be reused as it is, and the manufacturing cost can be reduced. Further, in this manufacturing method, since an ink cartridge that once stores ink or an ink cartridge having an ink storage portion that stores the ink is used, it is easy to fill the ink. In this respect, the manufacturing efficiency can be improved. Can do.

It is a schematic explanatory drawing of the ink cartridge suitable for performing recording using the ink concerning this invention. It is a schematic explanatory drawing of the ink cartridge suitable for performing recording using the ink concerning this invention. FIG. 3 is a schematic explanatory diagram from when ink is applied to a recording medium until fixing.

Explanation of symbols

41: Container 42: Lid members 43Y, 43M, 43C: Ink supply ports 44Y, 44M, 44C: Ink absorbers 45Y, 45M, 45C: Ink supply member 46: Retaining claw 47: Latch lever 47c: Base slope 48: Latch Claw 49: Stepped portion 112: Atmospheric communication port 114: Liquid supply port 132A: Second negative pressure generating member 132B: First negative pressure generating member 132C: First negative pressure generating member and second negative pressure generating member Boundary layer 134: negative pressure generating member storage chamber 136: liquid storage chamber 138: partition wall 140: communication hole 146: pressure contact body 150: air introduction groove (atmosphere introduction path)
411, 412: Partition plate L: Liquid-gas interface 1300: Recording medium 1301: Pigment having phthalocyanine skeleton 1302: Dye 1303: Aggregate of pigment having phthalocyanine skeleton

Claims (15)

An inkjet ink comprising water, a coloring material, and a water-soluble organic solvent,
The color material is C.I. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9, and a pigment having a copper phthalocyanine skeleton,
The water-soluble organic solvent includes a poor solvent for the pigment;
The pigment content A (% by mass) in the ink is less than 1% by mass based on the total mass of the ink,
The pigment content A (mass%) and the dye content D (mass%) based on the total mass of the ink have a relationship of 7% ≦ A / D × 100% ≦ 24.3%. An inkjet ink characterized by satisfying.   2. The inkjet according to claim 1, wherein the ratio (B / A) of the content B (mass%) of the poor solvent to the content A (mass%) of the pigment in the ink is 1 or more and 4 or less. For ink.   The inkjet ink according to claim 1 or 2, wherein the content (% by mass) of the pigment in the ink is 0.2% by mass or more based on the total mass of the ink. The water-soluble organic solvent contains a good solvent for the pigment;
The ratio (C / B) of the content C (mass%) of the good solvent to the content B (mass%) of the poor solvent in the ink is 0.3 or more and 2 or less. 4. The inkjet ink according to any one of 3 above.   The ink-jet ink according to any one of claims 1 to 4, wherein the poor solvent is at least one selected from polyethylene glycol having an average molecular weight of 1,000, 2-pyrrolidone, and 1,5-pentanediol. . The inkjet ink according to any one of claims 1 to 4, wherein the poor solvent is polyethylene glycol having an average molecular weight of 1,000. The good solvent is, ink-jet ink according to any one of claims 4 to 6 is at least one selected from glycerin and ethylene glycol. The inkjet ink according to claim 1, wherein the pigment having a copper phthalocyanine skeleton is dispersed by the action of an ionic group. The poor solvent is polyethylene glycol having an average molecular weight of 1,000, and the ratio (B / A) of the content B (mass%) of the poor solvent to the content A (mass%) of the pigment in the ink. ) Is 1 or more and 4 or less, The inkjet ink according to claim 1. A method for producing an ink-jet ink for obtaining the ink according to any one of claims 1 to 9 ,
An ink cartridge containing a pigment having a copper phthalocyanine skeleton and an ink containing a poor solvent for the pigment as a coloring material includes C.I. I. Direct Blue 199, C.I. I. Direct Blue 86, and C.I. I. A method for producing an inkjet ink, comprising a step of injecting an ink containing one or more dyes selected from the group consisting of Acid Blue 9. An inkjet ink obtained by the method for producing an inkjet ink according to claim 10 . An inkjet recording method for ejecting ink by an inkjet method, wherein the inkjet ink according to any one of claims 1 to 9 and 11 is used as the ink. An ink cartridge comprising an ink containing portion for containing ink, wherein the ink containing portion contains the ink-jet ink according to any one of claims 1 to 9 and 11. cartridge. A cyan ink used together with a black ink containing water, carbon black, and a water-soluble organic solvent,
Water, a coloring material, and a water-soluble organic solvent are contained. I. Direct Blue 199, C.I. I. Direct Blue 86 and C.I. I. One or more dyes selected from the group consisting of Acid Blue 9, and a pigment having a copper phthalocyanine skeleton,
As the water-soluble organic solvent, including a poor solvent for the pigment,
The pigment content A (% by mass) in the ink is less than 1% by mass based on the total mass of the ink,
The pigment content A (mass%) and the dye content D (mass%) based on the total mass of the ink have a relationship of 7% ≦ A / D × 100% ≦ 24.3%. Cyan ink characterized by filling. The poor solvent is, cyan ink according to claim 1 4, which is also a poor solvent for the carbon black in the black ink used together.

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