JPH06329945A - Monoazo dye compound, ink containing the same, recording with the ink, and apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain an ink which can form an image being clear and having a high density, nonblurring quality and excellent water resistance ad has good fixability, does not cause nozzle plugging, and excels in storage stability, heat stability and safety by incorporating a monoazo dye compound having specified structural units in an ink jet recording ink. CONSTITUTION:0.1-15wt.%, based on the entire ink weight, monoazo dye having structural units of the formula: -X-Y(R1)(R2)(R3)k [wherein X is a group for connecting a parent dye molecule with Y; Y is a six-membered ring having 2 or 3 nitrogen atoms; R1 is a residue of a first amino acid; R2 is H, OH, NH2, CH, =O or a residue of a second amino acid; R3 is H, OH, NH2, CN, or =O; k is 0 or 1; and M is Na, K or NH4] (the number of carboxyl groups is 1-4 per molecule, and the number of sulfonic acid groups is 1 or 2 per molecule) is added. As a liquid medium for dissolving or dispersing this compound, a mixture of water with a water-soluble organic solvent is used. The water content is 10-97.5wt.% based on the entire ink weight. The pH of the ink is 6-10.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel azo dye compound,
An ink containing the dye compound as a recording agent, an inkjet recording method using the ink, and more specifically, high print density on so-called plain paper such as high-quality paper, copy paper, bond paper, report paper, and irregular dots. The present invention relates to a novel azo dye compound suitable for an ink having small bleeding, fast fixing, and improved water resistance, an ink containing the dye compound, and an inkjet recording method using the ink.

[0002]

2. Description of the Related Art Conventionally, an aqueous ink in which a water-soluble dye is dissolved in an aqueous medium has been used as an ink for ink jet recording. In these conventional inks,
(1) To give an image of sufficient density, (2) Good dryness on the recording material, (3) Little bleeding on the recorded image, (4) Even when contacted with water, alcohol, etc. No recorded image flowing out, or sufficient readability even when flowing out (water resistance), (5) excellent light resistance of recorded image, (6) no clogging at pen tip or nozzle tip (7) When continuous recording is performed, when recording is started after being left for a long time, inconvenience such as blurring of a recorded image does not occur (ejection stability), (8) ink is stable during storage, (9) Inkjet recording using thermal energy, which is required to cause no problem when used in contact with a member constituting a recording unit, (10) has no problem in user safety, and the like. In addition to the above requirements, the method (11) Good and does not adversely affect the thermal energy generating means to heat, is required. Needless to say, these properties depend on the composition of the ink, but also largely depend on the properties of the dye contained as a recording agent. It is not easy to use the existing dyes to satisfy all the above required characteristics.

Existing aqueous dyes for ink jet recording have mainly used existing acid dyes or direct dyes. Since these have a sulfonic acid group as a solubilizing group, they are highly soluble in an aqueous ink medium and the long-term storage stability of the ink is also generally good. However, printed matter recorded on paper or other recording material with such ink will not flow out or bleed when dyed with water, touched with wet fingers, or traced with a water-based felt-tip pen. It often happened that the quality of the image was deteriorated and the readability was hindered.

JP-A-55-145773, JP-A-59-78273, JP-A-59-131657, JP-A-60-81266, and JP-A-60-1.
88468, JP 61-2773, JP 61-2774, JP 61-247770, JP 61-62562, and JP 63-2.
Japanese Patent No. 13582 discloses an ink in which various characteristics are improved by using a monoazo dye having a specified structure, but the water resistance of a recorded image is still insufficient.

Japanese Patent Laid-Open No. 57-59969 discloses an aqueous ink using an alkali metal salt of an amide derivative obtained by reacting an acidic group of an acidic dye with an aminocarboxylic acid as a colorant. Is complicated and difficult to operate, and the manufacturing cost of the colorant is high. Further, in order to balance the solubility and water resistance of the dye, it is necessary to control the ratio of the number of sulfonic acid groups and the number of carboxyl groups in the dye molecule, but this method is almost impossible. JP-A-1-141966 discloses an aqueous ink having a ratio of carboxylate group to sulfonate group in the molecule of 0.3 or more and containing a quaternary ammonium or lithium salt-forming dye. .
As is clear from the examples, this dye has a carboxyl group directly bonded to the aromatic ring of the molecule, but the production of such a special intermediate inevitably causes a large increase in cost. There is room for improvement in water resistance of images.

As described above, various attempts have been made to improve various properties such as water resistance at the same time, but the present situation is that the problems cannot be fully solved.

In addition to this, the dots of the printed matter do not cause irregular bleeding, and the shape is close to a circle.
There is a demand for an ink that has a sharp edge and gives a high-quality image, and an ink that fixes quickly after recording in response to an increase in printer speed.

Further, during the printing of a blank document or image, if a printing pause period is formed in the nozzle corresponding to the blank, the initial ejection direction tends to be disturbed at the time of restart, and as a result the print quality is degraded. There is also a need for inks that do not cause such problems.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a high image density and a clear image to various types of plain paper when it is contained in an ink as a recording agent.
An image with excellent quality and water resistance without irregular shape or irregular bleeding is obtained, and the fixing property is good, and clogging does not occur.
It is possible to make an ink with excellent storage stability, thermal stability, and safety that does not disturb the ejection direction during printing.
Moreover, it is to provide a novel monoazo dye compound having a low production cost, an ink containing the compound, and an inkjet recording method using the ink.

[0010]

The above object can be achieved by the present invention described below. That is, the present invention is a monoazo dye compound having a structural unit represented by the following formula in the molecule.

--X--Y (R ₁ ) (R ₂ ) (R ₃ ) _k (where Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a bond between the dye molecule base and Y). R ₁ represents a first amino acid residue, R ₂ represents an atomic group selected from the following group A, and R ₃ represents an atomic group selected from the following group B. _{: H, OH, NH 2,} CN, = O, the second amino acid residue B _{group: H, OH, NH 2,} CN, = O, where, k is the number 0 or 1, with the first The second amino acid residue may be the same or different, M is Na,
K or ammonium is shown. )

Further, the present invention provides an ink containing a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein the recording agent contains a monoazo dye compound having a structural unit represented by the following formula in the molecule. A characteristic ink, an inkjet recording method using the ink, and a device.

--X--Y (R ₁ ) (R ₂ ) (R ₃ ) _k (where Y is a 6-membered ring containing two or three nitrogen atoms, X is a bond between the dye molecule base and Y) R ₁ represents a first amino acid residue, R ₂ represents an atomic group selected from the following group A, and R ₃ represents an atomic group selected from the following group B. _{: H, OH, NH 2,} CN = O, the second amino acid residue B _{group: H, OH, NH 2,} CN = O, wherein, k is the number 0 or 1, the first and second Amino acid residues of may be the same or different, M is Na,
K or ammonium is shown. )

[0014]

According to the present invention, so-called plain paper such as high-quality paper, copy paper, bond paper, and report paper has high print density, small irregular dot bleeding, high image quality, fast fixing, and water resistance. Provided are a novel azo dye compound suitable for an ink having improved properties, an ink containing the dye compound, and an inkjet recording method using the ink.

This is because the dye of the present invention has a higher affinity for cellulose of paper than conventional dyes, and therefore, when printed with an ink using this, the dye does not penetrate into the paper together with the liquid medium. It stays near the surface of the paper, resulting in high optical density of printed matter, less irregular dot bleeding, and fast fixing speed.It has many advantages in addition to high water resistance. Conceivable.

(Preferred Embodiment) The present invention will be described in more detail with reference to the preferred embodiments. The following compounds are mentioned as preferable specific examples of the monoazo dye compound mainly characterizing the present invention.

[0017]

[Outside 9]

[0018]

[Outside 10]

[0019]

[Outside 11]

In the above structural formula, M represents Na, K or ammonium, all of which are preferable.
Ammonium bound to the carboxyl group becomes ammonia and is gradually volatilized after printing. As a result, the remaining dye becomes a hardly soluble or insoluble free acid form in water, which is effective in further improving water resistance. .

From the viewpoint of dissolution stability of the dye, it is preferable to have one or two sulfonic acid groups per molecule of the dye compound. However, at this time, it is preferable that the number of carboxyl groups is not smaller than the number of sulfonic acid groups in order to exhibit water resistance, and it is more preferable that the number is more than this.

The dye of the present invention as described above is synthesized according to the method described in Yutaka Hosoda, "Theoretical Manufacturing Dye Chemistry" and others. For example, specific example No. The dye of No. 1 is synthesized as follows. 2,4-Dimethylaniline is diazotized with sodium nitrite according to a conventional method, and is alkalinely coupled with H acid (1-amino-8-naphthol-3,6-disulfonic acid). Next, this product is reacted with cyanuric chloride at about 0 to 10 ° C, and finally with 2-fold molar glycine at 50 to 90 ° C to obtain the target compound.

As described above, the dye of the present invention can be manufactured at a low cost because the number of carboxyl groups introduced into one molecule can be strictly controlled and the existing intermediate is used.

The amount of the above dye used in the ink of the present invention is not particularly limited, but is generally 0.1 to 15% by weight, preferably 0.5 to 15% by weight based on the total weight of the ink.
Amounts occupying 10% by weight, more preferably 0.5 to 6% by weight are suitable. The above dyes can be used alone or in combination.

A suitable medium for use in the ink of the present invention is water or a mixed solvent of water and a water-soluble organic solvent. As the water, it is preferable to use deionized water instead of general water containing various ions.

Examples of the water-soluble organic solvent used as a mixture with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl. Alcohols having 1 to 5 carbon atoms such as alcohols and n-pentanol; amides such as dimethylformamide and dimethimeacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as dioxane; polyethylene glycol Polyalkylene glycols such as polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, Alkylene glycols having an alkylene group of 2 to 6 carbon atoms such as siren glycol and diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether Lower alkyl ethers of polyhydric alcohols such as treethylene glycol dimethyl (or ethyl) ether,
Lower dialkyl ethers of polyhydric alcohols such as tetraethylene glycol (or ethyl) ether; sulfolane, N-methyl-2-pyrrolidone, 1,3-dimethyl-
2-imidazolidinone etc. are mentioned.

An appropriate organic solvent is selected from the above organic solvents, and in the case of the dye of the present invention, diethylene glycol or thiodiglycol is particularly preferable for preventing clogging of the ink, and the image density and the ejection stability are improved. From the point of view, a nitrogen-containing cyclic compound or a polyalkylene oxide ether compound is preferable, and a lower alcohol or a surfactant is preferably used for frequency response. Therefore, the preferred solvent composition in the present invention is a composition containing various components as described above in addition to water. The content of the water-soluble organic solvent in the ink is generally 2 to 80% by weight, preferably 3 to 7% by weight based on the total weight of the ink.
It is 0% by weight, more preferably 4 to 60% by weight.

The amount of water used is generally 10 to 97.5% by weight, preferably 35% by weight or more, and more preferably 45% by weight or more of the whole ink. A large amount of low-volatile organic solvent remains in the formed image, which causes problems such as dye migration and image bleeding, which is not preferable.

In addition to the above components, the ink of the present invention may contain a pH adjusting agent, a viscosity adjusting agent, a surface tension adjusting agent, etc., if necessary. Examples of the pH adjuster include various organic amines such as diethanolamine and triethanolamine, and inorganic alkali agents such as alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide.

The ink of the present invention as described above has a viscosity at 25 ° C. of 1 to 20 cps, preferably 1 to 15 cps.
And the surface tension is 30 dyn / cm or more, preferably 40
It is preferable that the material has a physical property of dyn / cm or more and a pH of about 6 to 10.

The recording method in which the ink of the present invention is used is
An inkjet method is effective as a method, and as a recording material, general plain paper (for example, high-quality paper or medium-quality paper,
Any recording material such as bond paper), coated paper, and plastic film for OHP can be used.

The ink of the present invention is particularly suitable when applied to an ink jet recording method of the type in which the ink is ejected by the bubbling phenomenon of the ink due to thermal energy.
The ejection is extremely stable, and satellite dots are not generated. However, in this case, the thermal physical property value (for example, specific gravity, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

The ink of the present invention is particularly suitable for use in an ink jet recording system in which droplets are discharged by the action of heat or other energy for recording, but it goes without saying that it can also be used as a general writing instrument.

As a method and an apparatus suitable for recording using the ink of the present invention, a thermal energy corresponding to a recording signal is applied to the ink inside the chamber of the recording head, and a droplet is generated by the thermal energy. And devices.

An example of the head structure, which is the main part of the apparatus, is shown in FIGS. 1, 2 and 3.

The head 13 is a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 used for heat-sensitive recording (a head is shown in the drawing, but the invention is not limited to this). It is obtained by bonding and. The heating head 15 includes a protective film 16 made of silicon oxide, aluminum electrodes 17-1, 17-2,
Heat-generating resistor layer 18 and heat storage layer 1 formed of nichrome or the like
9. A substrate 20 having a good heat dissipation property such as alumina.

The ink 21 is a discharge orifice (fine hole) 2
2, the meniscus 23 is formed by a pressure (not shown).

Now, when an electric signal is applied to the electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 rapidly generates heat, and bubbles are generated in the ink 21 in contact therewith,
The meniscus 23 is projected by the pressure, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and is ejected toward the recording material 25. FIG. 3 shows an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head is manufactured by closely contacting a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described in FIG.

Incidentally, FIG. 1 shows the head 1 along the ink flow path.
3 is a sectional view of FIG. 3, and FIG. 2 is a sectional view taken along line AB of FIG. 1.

FIG. 4 shows an example of an ink jet recording apparatus incorporating such a head.

In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end, which is in the form of a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head, and in the case of this example, is held in a protruding form in the moving path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61, and has a configuration in which it moves in a direction perpendicular to the moving direction of the recording head and contacts the ejection port surface to perform capping. Further, 63 is an ink absorber provided adjacent to the blade 61, and like the blade 61, is held in a form protruding in the moving path of the recording head. The blade 61, the cap 62, and the absorber 63 form an ejection recovery unit 64, and the blade 61 and the absorber 63 remove water, dust, and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head which has an ejection energy generating means and ejects ink to a recording material facing the ejection port surface where the ejection ports are arranged for recording, and 66 denotes a recording head in which the recording head 65 is mounted. A carriage for moving 65. The carriage 66 slidably engages with the guide shaft 67, and a part of the carriage 66 is connected (not shown) to a belt 69 driven by a motor 68. As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and its adjacent area.

Reference numeral 51 designates a paper feed section for inserting a recording material, and 5
A paper feed roller 2 is driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the ejection port surface of the recording head, and is ejected to a paper ejection unit provided with a paper ejection roller 53 as the recording progresses.

In the above structure, when the recording head 65 returns to the home position after recording is completed, the cap 62 of the head recovery unit 64 is retracted from the movement path of the recording head 65, but the blade 61 is projected in the movement path. There is. As a result, the ejection port of the recording head 65 is wiped.
When the cap 62 comes into contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to project into the movement path of the recording head.

When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 6
1 is at the same position as the position at the time of wiping described above.
As a result, the ejection opening surface of the recording head 65 is wiped even during this movement.

The above-described movement of the recording head to the home position is performed not only at the end of recording or at the time of ejection recovery, but also at the home adjacent to the recording area at a predetermined interval while the recording head moves in the recording area for recording. It moves to Pojeong, and the wiping is performed along with this movement.

FIG. 5 is a diagram showing an example of an ink cartridge in which ink is supplied to the head through an ink supply member, for example, a tube. Here, 40 is an ink containing portion containing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into this stopper 42,
The ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives the waste ink. It is preferable for the present invention that the surface of the ink containing portion that comes into contact with the ink is made of polyolefin, especially polyethylene.

The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separately provided as described above, but is also suitable for the one in which they are integrated as shown in FIG. Used.

In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink containing portion containing ink, for example, an ink absorber is contained, and the ink in the ink absorber has a plurality of orifices. Head portion 71
It is configured to be ejected as an ink droplet from. For the present invention, it is preferable to use polyurethane as the material of the ink absorber.

Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere.

The recording unit 70 is used in place of the recording head shown in FIG.
It is removable with respect to 6.

[0052]

【Example】

(1) Preparation of ink The components shown in Table 1 below were mixed and dissolved using the exemplified compounds,
The ink of the present invention was prepared by filtering with a filter having a pore size of 0.2 μm. The pH of the ink was adjusted to be 9.0 to 9.5 with hydrochloric acid or aqueous ammonia. In the text, parts are based on weight.

[0053]

[Table 1]

(2) Example of ink usage An on-demand type multi-head (orifice diameter 40 × 40 μm, drive voltage) in which each of the above inks is subjected to thermal energy to the ink in the recording head to generate droplets for recording. It was mounted on a recording device having 32 V and a frequency of 3.5 kHz for printing, and the following evaluation was performed. The evaluation results are shown in Table 2 below.

(A) Printing density A solid patch is printed on two types of plain paper for copiers (Canon NP paper and Xerox 4024 paper) by simultaneously driving all nozzles, the optical density is measured, and the average value thereof is based on the following criteria. evaluated.

A: Optical density is 1.25 or more B: Optical density is 1.20 to 1.24 C: Optical density is 1.00 to 1.19 D: Optical density is 0.99 or less

(B) Occurrence rate of bleeding The above paper was continuously printed so that the dots did not come into contact with each other, and the proportion (%) of dots with irregular or irregular bleeding was counted under a microscope, and the average value was calculated. The following criteria evaluated.

A: 5% or less B: 6 to 10% C: 11 to 20% D: 21% or more

(C) Fixability Alphanumeric characters (60 characters x 40 lines, A4 size) are printed on the above-mentioned paper, and after a certain period of time, rubbing with lens cleaning paper, the average required time (seconds) until the printing does not fade Was evaluated according to the following criteria.

A: 10 seconds or less B: 11 to 15 seconds C: 16 to 30 seconds D: 31 seconds or more

(D) Light resistance The degree of discoloration after exposing the solid patch prepared in (a) above to room light for 2 months was determined as a reduction rate (average value) of optical density and evaluated according to the following criteria.

A: less than 10% B: 10-20% C: 20.1% or more

(E) Water resistance (e-1) The solid patch prepared in (a) above is gently immersed in tap water at 20 ° C. for 1 hour and then dried to obtain the reduction rate (average value) of optical density. The following criteria evaluated.

A: less than 10% B: 10-20% C: 20.1-40% D: 40.1% or more

(E-2) The printed matter prepared in the above (c) is dipped in tap water at 20 ° C. for 3 seconds, immediately pulled up and dried, and the degree of contamination of the white background due to the dye flowing out is determined according to the following criteria. evaluated.

A: Almost no pollution was observed B: Little pollution C: Somewhat pollution D: Very much pollution

(E-3) The characters of the printed matter prepared in (c) above were traced once in the row direction with a commercially available yellow fluorescent felt pen, and the degree of fading of the characters was evaluated according to the following criteria.

A: Almost no blurring is observed B: Little blurring C: Many blurring

(F) Ejection Stability 400 alphanumeric characters (60 characters × 40 lines) were printed on A4 size paper and evaluated according to the following criteria.

A: No abnormality B: Partial ejection failure or print disorder

(G) Nozzle Clogging The required number of recovery operations (suction operation by the built-in pump) when printing was performed after the printer was left at room temperature for 2 months with the nozzle capped was evaluated based on the following criteria. .

A: Normal printing within 1 time B: Normal printing after 2 to 4 times C: Normal printing after 5 to 10 times

[0073]

[Table 2]

Comparative Example An ink having the following ink composition was prepared using the dye compounds shown in Table 3 below in the same manner as in the above example, and the same evaluation as above was performed. The results are shown in Table 4.

Ink composition Diethylene glycol 15 parts 2-Pyrrolidone 5 parts Ethanol 3 parts Dye (M = Na) 3 parts Pure water 74 parts

[0076]

[Table 3]

[0077]

[Table 4]

In the case of Comparative Example 2, the dye was not sufficiently dissolved in the ink medium because of low solubility.

[0079]

As described above, according to the present invention, it is possible to obtain an image having high image density, sharpness, and free of irregular shape or irregular bleeding and excellent water resistance on various types of plain paper. A novel azo compound suitable for an ink having good fixing property, no clogging, excellent storage stability, thermal stability and safety, an ink containing this compound, and an inkjet recording method using this ink are provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a head portion of an inkjet recording device.

FIG. 2 is a vertical cross-sectional view of a head portion of an inkjet recording device.

FIG. 3 is an external perspective view of a head in which the heads shown in FIGS. 1 and 2 are multi-headed.

FIG. 4 is a perspective view showing an example of an inkjet recording apparatus.

FIG. 5 is a vertical sectional view of an ink cartridge.

FIG. 6 is a perspective view of an inkjet cartridge (same as a recording unit).

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display area C09B 29/08 A 7306-4H 29/16 7306-4H 29/30 7306-4H 29/46 7306-4H C09D 11 / 00 PSZ PTF (72) Inventor Takao Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (26)

[Claims] 1. A monoazo dye compound having a structural unit represented by the following formula in the molecule. —X—Y (R ₁ ) (R ₂ ) (R ₃ ) _k (where Y is a 6-membered ring containing 2 or 3 nitrogen atoms, and X is for connecting Y to the dye molecule base) R ₁ represents a first amino acid residue, R ₂ represents an atomic group selected from the following group A, and R ₃ represents an atomic group selected from the following group B. Group A: H, OH, NH ₂ , CN, ═O, second amino acid residue Group B: H, OH, NH ₂ , CN, ═O, where k is a number of 0 or 1 The amino acid residues may be the same or different, M is Na,
K or ammonium is shown. ) 2. The X is selected from the following C group:
The described compound. Group C: -NH -, - NHCO -, - NHCOCH 2 CH
_{2 -, - NHSO 2 -,} - O- 3. The Y is selected from the following D group:
The described compound. [Outer 1] 4. The number of carboxyl groups in one molecule is 1 to 4.
The compound according to claim 1, wherein the number of sulfonic acid groups is 1 or 2. 5. The following No. The compound according to claim 1, which is selected from 1 to 11 (M represents Na, K or ammonium). [Outside 3] [Outside 4] 6. An ink containing a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein the recording agent contains a monoazo dye compound having a structural unit represented by the following formula in the molecule. . —X—Y (R ₁ ) (R ₂ ) (R ₃ ) _k (where Y is a 6-membered ring containing 2 or 3 nitrogen atoms, and X is for connecting Y to the dye molecule base) R ₁ represents a first amino acid residue, R ₂ represents an atomic group selected from the following group A, and R ₃ represents an atomic group selected from the following group B. Group A: H, OH, NH ₂ , CN, ═O, second amino acid residue Group B: H, OH, NH ₂ , CN, ═O, where k is a number of 0 or 1 The amino acid residues may be the same or different, M is Na,
K or ammonium is shown. ) 7. The X is selected from the following C group:
Ink described. Group C: -NH -, - NHCO -, - NHCOCH 2 CH
_{2 -, - NHSO 2 -,} - O- 8. The Y is selected from the following D group:
Ink described. [Outside 5] 9. The ink according to claim 6, wherein the number of carboxyl groups in one molecule of the monoazo dye compound is 1 to 4, and the number of sulfonic acid groups is 1 or 2. 10. The pH is in the range of 6 to 10.
Ink described. 11. The ink according to claim 6, wherein the content of the recording agent is 0.1 to 15% by weight based on the total weight of the ink. 12. The ink according to claim 6, wherein the liquid medium is a mixture of water and a water-soluble organic solvent. 13. The ink according to claim 12, wherein the content of the water is 10 to 97.5% by weight based on the total weight of the ink. 14. A recording medium for ink jet recording.
Ink described. 15. The ink according to claim 14, wherein the ink jet recording is a system in which thermal energy is applied to the ink to eject ink droplets. 16. The recording material according to No. 16 below. The ink according to claim 5, which contains at least one selected from the group consisting of 1 to 11 (M represents Na, K, or ammonium). [Outside 6] [Outside 7] [Outside 8] 17. An inkjet recording method for performing recording by ejecting ink as ink droplets, wherein the ink is the ink according to claim 6. 18. The inkjet recording method according to claim 17, wherein the recording method is a method in which thermal energy is applied to eject the ink as ink droplets. 19. An inkjet according to claim 6, wherein the ink is the ink according to claim 6 in a recording unit including an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets. Recording unit. 20. The recording unit according to claim 19, wherein the head portion includes a head that applies thermal energy to the ink to eject ink droplets. 21. An ink cartridge comprising an ink containing portion containing ink, wherein the ink is
An ink cartridge, which is the ink described in 1. 22. An ink according to claim 6, wherein the ink is an ink jet recording apparatus including a recording unit having an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets. An ink jet recording apparatus characterized by the above. 23. The ink jet recording apparatus according to claim 22, wherein the head portion includes a head that applies thermal energy to ink to eject ink droplets. 24. An ink according to claim 6, wherein the ink cartridge is provided with an ink cartridge having an ink containing portion containing the ink, and a recording head for ejecting the ink as an ink droplet. An ink jet recording apparatus characterized by the above. 25. The ink jet recording apparatus according to claim 24, further comprising an ink supply unit that supplies the ink contained in the ink cartridge to the recording head. 26. The ink jet recording apparatus according to claim 24, wherein the recording head includes a head which applies thermal energy to ink to eject ink droplets.