JPH0593143A - Azo compound, ink containing the same, recording method using the ink, and device using the ink - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Not only can high-definition images with high image density and clear, irregular-shaped or irregular bleeding be obtained on various types of plain paper, A novel azo compound and its use suitable for inks that can obtain images with little discoloration even on coated paper, have good fixability and water resistance, do not cause clogging, and have excellent storage stability, thermal stability and safety Provide a way. An azo compound represented by the formula (A), a black dye composition containing the compound as a main component, an ink containing a recording agent and a liquid medium for dissolving or dispersing the same, an inkjet recording method using the same, Equipment using such ink. (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1
~ 4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. )

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel azo compound, an ink containing the azo compound as a recording agent, an ink jet recording method using the ink, and a device using the ink. Paper,
Non-coated paper such as bond paper and report paper, which is suitable for inks with high printing density and so-called plain paper, and which has an ink-receiving layer on the surface of which the recording material is a binder and pigment. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel azo compound suitable for an ink having an improved indoor discoloration property of an image recorded on a so-called coated paper, an ink containing the compound, an inkjet recording method using the ink, and a device 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. The recorded image does not flow out or is sufficiently readable even if it flows out (water resistance), (5) has excellent light resistance of the recorded image, (6) does not cause clogging at the pen tip or nozzle tip, (7) No inconvenience such as blurring of a recorded image occurs when continuous recording is performed, recording is started after being left for a long time (ejection stability), (8) ink is stable during storage, (9) ) In use, it is required that there is no problem even if it comes into contact with a member that constitutes the recording means, (10) there is no problem in the safety of the user, and in the inkjet recording method that uses heat energy. In addition to the above requirements, (11) Excellent heat resistance And it does not adversely affect the thermal energy generating means, is required.

These properties are of course dependent on the composition of the ink, but are largely governed by the properties of the dye contained as a recording agent. It is not easy to use the existing dyes to satisfy all the above requirements.

Specific examples of dyes include, for example, C.I. for both monocolor and full-color images in the field of ink jet recording. I. Hood Black 2 has been mainly used (Japanese Patent Laid-Open No. 59-93766 and 59).
-93768 gazette).

C. I. The ink using hood black 2 is excellent in that it gives an image of sufficient density, but it still has problems in light resistance and water resistance. That is, if the printed matter is exposed to room light for a long time or is displayed near the copying machine, the black color changes to brown, and the image quality is significantly deteriorated. Especially when it's too big). In addition, there is a problem that it becomes difficult to read when a test is performed on the assumption that water is spilled on the image.

JP-A-55-144067 and JP-A-61-285276 disclose inks having improved storage stability and ejection response by specifying a dye structure. Is not yet water resistant.
Furthermore, the former ink has not solved the above-mentioned problem of discoloration.

An ink in which the ejection stability, the water resistance of an image and the like are improved by introducing at least one specific structural unit into the dye structure is disclosed in JP-A-1-135880. Further, JP-A-1-193375 discloses a black ink which has a high affinity for a recording material, is excellent in fixability and water resistance and gives good print quality to plain paper. Japanese Patent Publication 62-102
Japanese Patent Publication No. 74 discloses an ink in which ejection stability, light resistance of an image and the like are taken into consideration. JP-A-3-781 and JP-A-3-782 disclose inks that are less likely to be clogged and have less discoloration. JP-A-3-294366
JP-A-3-294367 and JP-A-3-294367 disclose inks with little discoloration.

The ink is required to have a performance adapted to the recording system first, and secondly after satisfying the performance.
In addition, it is required to exhibit sufficient performance as a printed matter, that is, in terms of quality and robustness. However,
It is quite difficult to satisfy all of the various required performances, as seen in the above-mentioned known examples.

Although the problem has not been so much in the past, many problems have been solved by the progress of technology, and as a result, attention has been paid to the problem of discoloration.
The effect is particularly significant in black ink, which is used in large amounts, and in the case of a full-color image, this discoloration causes a sharp deterioration in image quality.

This problem of discoloration progresses even in a room where direct sunlight is not exposed, and depends on the type of recording material for forming an image, and is remarkable in paper containing a pigment such as silica. Conventionally widely used C.I. I. Food Black 2 couldn't solve this problem.

By selecting a dye having good light fastness, C.I. I. Attempts have been made to solve the drawbacks of Food Black 2 and satisfactory results have been obtained for plain paper. However, in the case of so-called coated paper in which an ink receiving layer containing a pigment and a binder is formed on a substrate such as paper in order to enhance image quality such as color developability, sharpness and resolution of dyes, Even if the ink has few problems on paper, remarkable color change occurs, and it is a problem that cannot be solved simply by selecting a dye having good light resistance.

In addition, as a compound similar to the compound of the present invention, JP-A-55-152747 discloses a compound that dyes cellulosic fiber material, paper or leather black.

[0013]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a high image density and a clear image on various types of plain paper when it is contained in an ink as a recording material.
Suitable for inks that can obtain images with excellent quality and water resistance without irregular shape or irregular bleeding, good fixability, no clogging, excellent storage stability, thermal stability and safety. Another object of the present invention is to provide a novel azo compound, an ink containing the compound, an inkjet recording method using the ink, and a device using the ink. A second object of the present invention is to provide a novel azo compound suitable for an ink in which the discoloration of an image is small even when printed on coated paper.

[0014]

The above object can be achieved by the present invention described below. That is, the present invention is an azo compound represented by the following general formula (A).

[0015]

[Outside 13] (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. )

The present invention is a black dye composition containing an azo compound represented by the following general formula (A) as a main component.

[0017]

[Outside 14] (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. )

The present invention is 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 novel azo compound represented by the following general formula (A). An inkjet recording method using ink, and a device using such ink.

[0019]

[Outside 15] (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. )

[0020]

According to the present invention, by containing the compound of the general formula (A) as a recording agent for ink, not only the density of recorded image is high and the water resistance is excellent when recorded on plain paper. An ink that gives a black image with little discoloration even when recorded on coated paper, an inkjet recording method using the same, and a device using the ink are provided.

(Preferred Embodiment) The present invention will be described in more detail with reference to the preferred embodiments.

Specific preferred examples of the azo compound (dye) represented by the general formula (A) which characterizes the present invention include the following compounds (dye) (M is an alkali metal or ammonium or an organic compound). Represents ammonium).

[0023]

[Outside 16]

[0024]

[Outside 17]

[0025]

[Outside 18]

Among these, more preferred specific examples include the following compounds.

[0027]

[Outside 19]

[0028]

[Outside 20]

[0029]

[Outside 21]

The azo compound (dye) of the present invention is generally a sodium salt of a water-soluble group such as a sulfonic acid group, but is not limited to these sodium salts in the present invention.
Even if those counter ions are potassium, lithium, ammonia, organic amines and the like, the same effect is obtained, and the present invention also includes dyes containing these other counter ions. The dye of the present invention can be used as a good black pigment.

The above dyes are manufactured by Yutaka Hosoda, "Theoretical Manufacturing".
It is synthesized as follows according to the method described in "Dye Chemistry" and the like.

Synthesis Example Specific Example No. The dye of 3 is synthesized as follows. m-
Chloroaniline is diazotized by a conventional method and coupled with 2,5-dimethoxyaniline to separate the resulting monoazo form. This is diazotized and alkali-coupled with gamma acid to separate the disazo form. Further, this is diazotized, coupled with m-phenylenediamine-4-sulfonic acid, salted out with sodium acetate and washed with ethanol for purification to obtain the desired dye. The dye of the present invention can be used in the form of powder or in the form of an aqueous solution (liquid composition). Further, in the latter case, a solubilizing agent for the dye can be used in combination.

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 with conventionally known dyes.

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.

The water-soluble organic solvent used by mixing with water is, for example, 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 alcohol and n-pentanol; amides such as dimethylformamide and dimethimeacetamide; ketones and 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-mentioned organic solvents and used. In the case of the dye of the present invention, diethylene glycol or thiodiglycol is particularly suitable for preventing clogging of the ink, and image density and ejection stability are improved. From the point of view, a nitrogen-containing cyclic compound or an ether compound of polyalkylene oxide is preferable, and it is more preferable to use a lower alcohol or a surfactant 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, more preferably 45% by weight or more, based on 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 and the like, if necessary. Examples of the pH adjusting agent include various organic amines such as diethanolamine and triethanolamine, inorganic alkali agents such as alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide, and organic acids such as lithium acetate. Examples thereof include salts, organic acids and mineral acids.

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 4 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, OHP plastic film and the like 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, a thermal 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 ejected by the action of heat 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 in 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 is not limited to this). It is obtained by bonding and. The heating head 15 includes a protective film 16 made of silicon oxide or the like, aluminum electrodes 17-1 and 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 flies 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 adhering 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, it is held in a protruding form in the moving path of the recording head. Reference numeral 62 denotes a cap, which is arranged in the home portion adjacent to the blade 61, and has a configuration for moving in a direction perpendicular to the moving direction of the recording head to come into contact with the ejection port surface for 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 constitute 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 having ejection energy generating means for ejecting ink to a recording material facing the ejection port surface where ejection ports are arranged for recording, and 66 a recording head having the recording head 65 mounted thereon. A carriage for moving 65. The carriage 66 slidably engages with a 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 feeding 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 opening surface of the recording head, and is ejected to the ejection section provided with the 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 section 64 is retracted from the movement path of the recording head 65, but the blade 61 is projected into 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 and 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 the ink is supplied to the head through an ink supply member, for example, a tube. Here, 40 is an ink containing portion containing the ink for supply, 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 contacts the ink is formed of polyolefin, particularly 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 separated as described above, and is preferably 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.

[0061]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, unless otherwise specified, the word "middle part" is based on weight.

(Example 1) Specific example No. Synthesis of 2-1 (1) Synthesis of monoazo compound <1> 0.2 mol of dimethoxyaniline is dispersed in 400 ml of water, hydrochloric acid is added to dissolve it, and the mixture is filtered.

<2> 0.2 mol of p-ethylaniline is dissolved in 300 ml of dilute hydrochloric acid, 200 g of ice, 40 g of hydrochloric acid and an aqueous solution of 0.2 mol of sodium nitrite are added, and the mixture is cooled with ice.
Stir for a few minutes to diazotize and add sulfamic acid.

<3> 200 g of ice is added to the above, and the diazo solution is poured while cooling with ice. At the same time, a 20% aqueous sodium hydroxide solution is added to maintain the pH at 3-4.

<4> After stirring for 3 hours under ice cooling, 50 g of sodium chloride is added for salting out, and suction filtration is performed. Dilute hydrochloric acid (pH ~
1) Disperse in 1.5 l, stir, add 50 g of sodium chloride, and filter by suction.

(2) Synthesis of disazo body <5> DMF30 was used as a wet cake of the above monoazo body.
It is dissolved in 0 g, 150 g of ice, 60 g of hydrochloric acid and an aqueous solution of 0.2 mol of sodium nitrite are added, and the mixture is stirred for 2 hours while cooling with ice to diazotize and add sulfamic acid.

<6> 0.2 mol of gamma acid is added to 200 ml of water
Disperse in, add sodium hydroxide and dissolve,
Add g.

<7> The above diazo solution is poured while cooling with ice. Adjust the pH to 9-10 with 20% sodium hydroxide.
Keep on.

<8> After stirring under ice-cooling for 5 hours, 30 g of sodium acetate was added and the mixture was centrifuged. The precipitate was dissolved in 1.5 l of water, 20 g of sodium acetate was added, the pH was adjusted to 4 with acetic acid, and the mixture was centrifuged.

(3) Synthesis of trisazo body <9> DMF300 was used as a wet cake of the above disazo body.
g, dissolved in 100 g of ice, 60 g of hydrochloric acid and 0.2 mol of sodium nitrite, and stirred for 2 hours while cooling with ice to diazotize and add sulfamic acid.

<10> 0.2 mol of m-phenylenediamine-4-sulfonic acid is dispersed in 300 ml of water, sodium hydroxide is added thereto to dissolve it, and 150 g of ice is added.

<11> The above diazo solution is poured while cooling with ice. Stir for 7 hours at pH 4-5.

<12> 30 g of sodium acetate is added and the mixture is centrifuged. The precipitate is dispersed in 1 liter of water, the pH is adjusted to 10 and 20 g of sodium acetate is added and the mixture is centrifuged.

<13> The precipitate is dispersed in 3 liters of a 1: 1 mixture of ethanol-water, dissolved by heating, filtered, and the filtrate is cooled, and the deposited precipitate is filtered and dried. Yield 65g. Maximum absorption wavelength 5
76 nm (water).

(Example 2) Specific example No. Synthesis of 3-1 It is similarly synthesized by using m-chloroaniline instead of the above-mentioned p-ethylaniline. Maximum absorption wavelength 578 nm (water).

(Example 3) Specific example No. Synthesis of 4-1 It is similarly synthesized by using 2-amino-4-chlorotoluene in place of the above P-ethylaniline. Maximum absorption wavelength 575 nm (water).

(Example 4) Specific example No. Synthesis of 5-1 It is similarly synthesized by using m-toluidine in place of the above p-ethylaniline. Maximum absorption wavelength 575
nm (water).

(Examples 5 to 16) (1) Preparation of ink The components shown in Table 1 below were mixed and dissolved, and filtered using a filter having a pore size of 0.2 μm to obtain inks shown in Table 1 below. In addition,
All the dyes used were those sufficiently desalted and purified by an appropriate method such as reverse osmosis or ultrafiltration.

[0079]

[Table 1]

As described above, the ink of any of the examples was obtained as a good black ink.

(2) Examples of ink use On-demand type multi-heads (orifice size 50 ×) in which each ink described in Table 1 above is subjected to recording by applying heat energy to the ink in the recording head to generate droplets.
Post-recording Table 2 shows the evaluation results of the printing performance, the ejection performance and the storage stability when the printing is performed by mounting the printing apparatus on a recording device having 40 μm, a driving voltage of 30 V and a frequency of 4 KHz). The evaluation and conditions of each evaluation item are as follows.

(1) Printing Density: Commercially available continuous slip paper is printed by driving all nozzles simultaneously, a patch is prepared, and naturally dried in a room for 24 hours, and then the optical density of the patch is measured and measured according to the following criteria. Evaluated. A: Optical density 1.31 or more B: Optical density 1.26 to 1.30 C: Optical density 1.10 to 1.25 D: Optical density 1.09 or less

(2) Occurrence rate of bleeding: Commercially printed continuous slip paper was continuously printed so that 300 dots did not come into contact with each other, and naturally dried in a room for 24 hours, and then irregular or irregular bleeding was observed with a microscope. The number of generated dots was counted and the percentage was evaluated according to the following criteria. A: 6% or less B: 7 to 12% C: 13 to 35% D: 36% or more

(3) Fixing property (printing and drying property): After printing alphanumeric characters on a commercially available continuous slip paper, 10, 20, 30,
After 40, 50, and 60 seconds, the printed portion was rubbed with a lens cleaning paper, and the number of seconds until the printed portion was not stained was measured and evaluated according to the following criteria. A: Within 10 seconds B: 11-20 seconds C: 21-40 seconds D: 41 seconds or more

(4) Indoor discoloration: A patch was prepared by printing on coated paper (designated paper for Canon PixelPro ^TM ) with all nozzles simultaneously driven, and the degree of discoloration after exposure to room light for 3 months was determined by color difference. It was measured with a meter and ΔH ^* (hue difference) was calculated and evaluated according to the following criteria. A: [Delta] H ^* is less than 5 B: ΔH ^* is 5~19.99 C: ΔH ^* is 20 or more

(5) Water resistance: Tap water is placed in a petri dish and allowed to stand. The patch evaluated in (1) above was gently immersed therein, left for 15 minutes and then dried.

(5a) The optical density was measured in the same manner as in (1) above, and the residual ratio of optical density (optical density after immersion / optical density before immersion × 100;%) was calculated and evaluated according to the following criteria. .. A: Remaining optical density is 90% or more B: Remaining optical density is 80 to 89% C: Remaining optical density is 60 to 79% D: Remaining optical density is 59% or less

(5b) The degree to which the dye in the printed portion of the paper flows out and is redeposited and contaminated on the white background was evaluated according to the following criteria. A: Almost no pollution. B: Little pollution. C: There is much pollution.

(6) Discharge stability: 100 sheets of continuous slip paper were printed and evaluated according to the following criteria. A: No abnormality B: No ejection or print disturbance

(7) Clogging (fixing recovery property): left in a constant temperature bath at 60 ° C. for 1 month, and then left at room temperature for 24 hours to perform recovery operation (absorption operation by pumping) and then print. The following criteria were evaluated. A: Return to normal printing state within 2 times of recovery operation B: Return to normal printing state within 3 to 5 times of recovery operation C: Non-ejection or print disturbance occurs after 6 to 10 times of recovery operation

(8) Storage stability: 100 cc of each ink was placed in a heat-resistant glass bottle, tightly closed and stored in a constant temperature bath at 60 ° C. for 3 months, and then printed on 100 sheets of continuous slip paper,
The following criteria were evaluated. A: No abnormality B: No ejection, print disorder or discoloration

[0092]

[Table 2]

Comparative Examples 1 to 12 Inks of Table 4 below were prepared using the dye compounds shown in Table 3 below, and the inks of Example 5 were prepared.
It evaluated similarly to -16. The results are shown in Table 5.

[0094]

[Table 3]

[0095]

[Table 4]

[0096]

[Table 5]

[0097]

[Table 6]

[0098]

[Table 7]

[0099]

As described above, in the present invention, by using the compound (dye) represented by the general formula (A) as a dye in ink, not only water resistance but also various performances required for printing on plain paper can be obtained. It is possible to obtain a filling ink. Further, it is possible to provide a black image having high image quality, excellent resolution, less discoloration even when printed on coated paper, and excellent in fastness.

In addition, the ink of the present invention has an ink pH of 4
Since the above characteristics are sufficiently exhibited even in the neutral range of 10 to 10, the addition of a strong alkaline substance as described in JP-A-56-57862 is not required and it is preferable in terms of safety.

Furthermore, even when the compound of the present invention is applied to an ink jet recording method in which ink is ejected by the action of thermal energy, it does not generate deposits on the heater and can be used stably for a long time. is there. Further, there is no change in physical properties or precipitation of solid matter during storage.

[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).

[Explanation of symbols]

 61 Wiping Member 62 Cap 63 Ink Absorber 64 Ejection Recovery Section 65 Recording Head 66 Carriage

Claims (36)

[Claims] 1. An azo compound represented by the general formula (A): (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. ) 2. The following No. The compound according to claim 1, which is selected from 1 to 12 (M represents an alkali metal, ammonium or organic ammonium). [Outside 2] [Outside 3] [Outside 4] 3. A black dye composition containing an azo compound represented by the following general formula (A) as a main component. (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. ) 4. The following No. The black dye composition according to claim 3, which contains an azo compound selected from 1 to 12 as a main component (M represents an alkali metal or ammonium or organic ammonium). [Outside 6] [Outside 7] [Outside 8] 5. An ink containing a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein the recording agent contains an azo compound represented by the following general formula (A). [Outside 9] (However, R ₁ , R ₂ or R ₃ are each a hydrogen atom or a carbon number 1 to
4 alkyl group, methoxy group, halogen atom, COO
Represents a group selected from the group consisting of M and COOR ₄ , wherein R ₄ represents an alkyl group having 1 to ₄ carbon atoms, and M represents an alkali metal, ammonium or organic ammonium. ) 6. The following No. 1 is used as the recording agent. The ink according to claim 5, containing at least one selected from 1 to 12 (M represents an alkali metal or organic ammonium). [Outside 10] [Outside 11] [Outside 12] 7. The ink according to claim 5, wherein the pH of the ink is in the range of 4 to 10. 8. The ink according to claim 5, wherein the recording agent accounts for 0.1 to 15% by weight of the total weight of the ink. 9. The ink according to claim 5, wherein the liquid medium contains a mixed solvent of water and a water-soluble organic solvent. 10. The content of water is 10 to 9 of the total ink.
The ink according to claim 9, which accounts for 7.5% by weight. 11. The ink according to claim 9, wherein the content of the water-soluble organic solvent accounts for 2 to 80% by weight of the total weight of the ink. 12. The ink according to claim 9, wherein the water-soluble organic solvent contains glycol. 13. The ink according to claim 12, wherein the glycol is diethylene glycol and / or thiodiglycol. 14. The ink according to claim 5, which is for inkjet. 15. The ink according to claim 14, wherein the ink comprises at least a recording agent, a water-soluble organic solvent and water. 16. The ink according to claim 15, wherein the water-soluble organic solvent contains glycol. 17. The ink according to claim 16, wherein the glycol is diethylene glycol and / or thiodiglycol. 18. The ink according to claim 17, which contains at least 2-propanol and / or triethanolamine as an additive. 19. The ink according to claim 18, wherein the ink comprises at least a recording agent, water, thiodiglycol, 2-propanol and triethanolamine. 20. An inkjet recording method for recording on a recording material using ink droplets, wherein the ink is the ink according to claim 5. 21. The ink jet recording method according to claim 20, wherein heat energy is applied to the ink to eject ink droplets. 22. The ink jet recording method according to claim 20, wherein the recording material is uncoated paper or coated paper. 23. A recording unit comprising an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets, wherein the ink is the ink according to claim 5. unit. 24. The head portion is a head which causes thermal energy to act on ink to eject ink droplets.
The recording unit according to 3. 25. A recording medium for ink jet recording.
The recording unit according to 3. 26. An ink jet recording method, wherein recording is performed by applying ink droplets to a recording material using the recording unit according to any one of claims 23 to 25. 27. The ink according to claim 5, wherein the ink is provided in an ink cartridge having an ink containing portion for containing ink.
An ink cartridge, which is the ink described in 1. 28. The ink storage unit has a bag structure.
7. The ink cartridge according to item 7. 29. The ink cartridge according to claim 27, wherein the ink containing portion has a liquid contact surface formed of polyolefin. 30. The ink cartridge according to claim 27, which is for inkjet. 31. An ink jet recording method, wherein recording is performed by applying ink droplets to a recording material using the ink cartridge according to claim 27. 32. An ink jet recording apparatus comprising the recording unit according to any one of claims 23 to 25, wherein the ink is the ink according to claim 5. 33. The ink jet recording apparatus according to claim 32, further comprising a carriage of the recording unit. 34. An ink jet recording apparatus comprising the ink cartridge according to claim 27 and a head. 35. The ink jet recording apparatus according to claim 34, further comprising an ink supply system for supplying the ink contained in the ink cartridge to the recording head. 36. The ink jet recording apparatus according to claim 34, wherein the recording head is a head which applies thermal energy to ink to eject ink droplets.