JPH07102199A - Ink, recording method and apparatus using the same - Google Patents

Abstract

PURPOSE:To obtain an ink for ink-jetting having excellent solubilization stability and an ideal black tint by using a specific coating mixture as a coloring agent and dissolving thc mixture in a liquid medium containing a polyhydric alcohol, an aliphatic monohydric alcohol, urea, an ammonium salt of inorganic acid and a hydroxide. CONSTITUTION:The ink is prepared by dissolving a coloring agent containing (A) at least one of dyes of the formula (R is NH4; Y is H, SO3R) and (B) a yellow dye containing C. I. acid yellow 17: 1, C. I. acid yellow 23 or the like in the liquid medium. The liquid medium contains a polyhydric alcohol, an aliphatic monohydric alcohol, urea, an ammonium salt of inorganic acid and a hydroxide. It shows excellent water resistance, when ordinary paper, for example, for copying or reporting, is recorded with the ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet ink, and especially for all kinds of recording materials, particularly copy paper, report paper, notebooks, notepaper, bond paper, continuous slips used in offices and homes. Ink suitable for non-coated paper such as paper, so-called plain paper, which has an ideal black color, has excellent dissolution stability, and uses heat energy that enables high image quality recording, A recording method and apparatus using the ink.

[0002]

2. Description of the Related Art Conventionally, ink jet inks having various compositions have been reported. The performance required for such ink jet inks is as follows: (1) good color tone and image density. High quality and sharpness (2) High quality images with no irregular or irregular bleeding on any recording material (3) Fast fixability on recording material (4 ) The water resistance and light resistance of the printed matter are excellent. (5) The dissolution stability of dyes and the like is good, and the fine discharge ports are not clogged. (6) The storage stability is good (7) It has excellent safety.

In order to satisfy these conditions, detailed research and development have been carried out from various aspects such as ink composition and physical properties, but none satisfying all the conditions has been found yet.

In particular, in recent years, there has been a particular demand for water resistance when recorded on plain paper such as copy paper, report paper, notebook, notepaper, bond paper, and continuous slip paper that are commonly used in offices.

For example, JP-A-2-296878 and JP-A-2-255876 propose that a water-based ink composition contains a polyamine. However, in such an ink, since the hydrophilic group of the dye is salted, the solubility of the ink is reduced and the reliability such as clogging is reduced, and bronzing is caused on the printed matter, resulting in uneven printing or density. There are things that are not. Further, it may be considered that a large amount of a dissolution stabilizer is contained in the ink for the purpose of increasing the solubility of the ink. In this case, however, since a large amount of the dissolution stabilizer needs to be added, it was formed using such an ink. The image quality of the recorded matter also deteriorates.

Further, JP-A-3-91577 discloses that when a dye having a specific structure having a carboxyl group is an ammonium salt or a volatile substituted ammonium salt, ammonia or amine is volatilized on a recorded matter, It has been proposed to improve the water resistance by becoming a free acid. However, even in this case, even if the initial solubility of the ink is good, the solubility may decrease due to the gradual volatilization of ammonia or amine in the ink, which may cause clogging and decrease the stability of the ink. There are many. For the same reason, bronzing is also likely to occur on a recorded matter, especially on acid paper.

Further, since the dye structure is specified, the color tone is slightly bluish purple, and there is a problem with the color tone.

The problem of color tone is becoming more important as color recording progresses. That is, it is of course ideal that the black ink is a black color close to the primary color even when printing in monochrome, but further, when printing a full-color image, not only magenta, yellow, and cyan In order to obtain a well-balanced and ideal color reproduction, it is required that the black ink exhibit a color close to the primary color.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to copy papers, report papers, notebooks, notepapers, bond papers, continuous slip papers used for recording on any recording material, especially those used in offices and homes. Uncoated paper, such as
An object of the present invention is to provide an ink having excellent water resistance when recorded on so-called plain paper, having an ideal black color, and excellent in dissolution stability, an inkjet recording method using the same, and a device using the ink. .

Another object of the present invention is to obtain an ink having a high recorded image and a high-quality image free from irregular or irregular bleeding, which solves the problems of nozzle clogging and storage stability. An object of the present invention is to provide an inkjet recording method using the same and a device using the ink.

[0011]

The above object can be achieved by the present invention described below.

That is, the present invention provides an ink containing a colorant and a liquid medium which dissolves the colorant, wherein the colorant is at least one of the dyes represented by the following structural formula (a): C.I.
I. Acid Yellow 17: 1, C.I. I. Acid Yellow 23, C.I. I. Acid Yellow 49, C.I. I. Acid Yellow 65, C.I. I. Acid Yellow 10
4, C.I. I. Acid Yellow 183, C.I. I. Acid Yellow 155, C.I. I. Acid Yellow 194,
C. I. Direct Yellow 86, C.I. I. Direct Yellow 106, C.I. I. Direct Yellow 142,
C. I. At least one yellow dye selected from Direct Yellow 194, the liquid medium contains at least one polyhydric alcohol and an aliphatic monohydric alcohol,
The ink is characterized by containing urea, an ammonium salt of an inorganic acid, and a hydroxide.

[0013]

[Outside 3]

Further, the present invention is an ink jet recording method for recording by ejecting ink as ink droplets, wherein the ink contains a coloring agent and a liquid medium which dissolves the coloring agent, and the coloring agent is as follows. At least one of the dyes represented by structural formula (a); I. Acid Yellow 17: 1, C.I. I. Acid Yellow 23, C.I. I.
Acid Yellow 49, C.I. I. Acid Yellow 6
5, C.I. I. Acid Yellow 104, C.I. I. Acid Yellow 183, C.I. I. Acid Yellow 155,
C. I. Acid Yellow 194, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 106,
C. I. Direct Yellow 142, C.I. I. At least one yellow dye selected from Direct Yellow 194, the liquid medium contains at least one polyhydric alcohol and an aliphatic monohydric alcohol, and further urea, an ammonium salt of an inorganic acid, and a hydroxide. And an apparatus used for the method.

[0015]

The present inventors conducted extensive studies on various ink compositions in order to obtain a black ink having excellent water resistance, good dissolution stability, and a color close to the primary color. As a result, a specific dye was used in combination as a colorant. And by using a specific medium,
Without impairing the water resistance of the dye represented by the structural formula (a), the recorded image is further high, and a high-quality image free of irregular shape or irregular bleeding is obtained, and the nozzle is not clogged. The present invention has been accomplished by finding that an ideal black ink having good storage stability can be obtained.

(Preferred Embodiment) The present invention will be described in more detail with reference to the preferred embodiments. The total content of the dye represented by the structural formula (a) used as a colorant in the present invention and the above-mentioned yellow dye in the ink is 0.1 to 1
It is in the range of 5% by weight, preferably in the range of 0.1 to 10% by weight. The mixing ratio of the dye represented by structural formula (a) to the yellow dye is preferably 40: 1 to 4: 1 by weight, more preferably 20: 1 to 5: 1. That is, when the mixing ratio of the yellow dye is smaller than this range, the color tone remains bluish, and conversely, when the mixing ratio of the yellow dye is larger than this range, it becomes greenish and an ideal black color cannot be obtained.
Further, by using the dye represented by the structural formula (a) in combination with a yellow dye, that is, by using a plurality of types of dyes, the dissolution stability of the dye is increased and the nozzle clogging is prevented as compared with the case of using them alone. It becomes difficult to wake up.

More preferred examples of the polyhydric alcohol used in the present invention include ethylene glycol, diethylene glycol, thiodiglycol and glycerin. In general, as the liquid medium, in addition to polyhydric alcohols, glycol ethers, glycol ether esters, amides, nitrogen-containing heterocyclic ketones, etc. are known.
It has good solubility in dyes, does not cause clogging, does not easily cause bleeding on printed matter, and has good fixability compared to it.In addition, it generally has a higher ability to dissolve dyes than nitrogen-containing compounds. Considering that there is no concern about safety such as odor and toxicity, polyhydric alcohol is most preferable for the present invention.

The present invention further comprises urea. The contents of the polyhydric alcohol and the urea in the ink are clogged, and considering the bleeding fixability, each is preferably 1 to 15% by weight.

Next, the aliphatic monohydric alcohol used in the present invention is indispensable for controlling the fixing property on the printed matter, that is, the drying property, and is irregular and irregular. It has the effect of promoting fixability without causing regular bleeding. Examples of the aliphatic monohydric alcohol include methanol, ethyl alcohol, isopropyl alcohol, 2-butanol and the like, and the content in the ink is preferably 0.1 to 5% by weight.

Further, the present invention contains a hydroxide and an ammonium salt of an inorganic acid. Hydroxide alone increases the dye solubility, but obviously impairs water resistance. Further, the solubility of the dye increases only with the ammonium salt of the inorganic acid, but its effect is lower than that of the hydroxide. However, by using a hydroxide in combination with an ammonium salt of an inorganic acid, the dye's water stability is not impaired, and the dissolution stability of the dye is better than when an ammonium salt of an inorganic acid is contained, resulting in nozzle clogging. It is possible to effectively prevent the occurrence of bronze, to eliminate bronze of the printed matter, and to obtain stable ejection.

Examples of the ammonium salt of an inorganic acid include ammonium carbonate, ammonium chloride, ammonium phosphate, ammonium borate, ammonium acetate, ammonium sulfate and the like, and particularly preferable example is ammonium sulfate. Examples of the hydroxide include lithium hydroxide, sodium hydroxide, ammonium hydroxide and the like, particularly preferably sodium hydroxide and lithium hydroxide, and the content of each of these in the ink is 0.1 to 0.1%.
It is preferable to adjust the pH of the ink to 1.0% by weight and the pH of the ink to 7 to 10.

The recording material of the ink of the present invention may be any recording material. The recording material referred to here is not limited to plain paper such as copy paper, report paper, notebook, notepaper, bond paper, and continuous slip paper, which are generally used in offices and homes, that is, not limited to plain paper. Any known recording material is known as a recording material, and includes cloth such as cotton, silk, polyester nylon and the like, OHP sheets, metal, wood chips, etc. Available. Further, when these recording materials are used, those processed by a known method may be used.

Among these, the effect is remarkable especially when used for plain paper.

The recording method of the present invention is a recording method characterized by using the ink prepared as described above, and is particularly preferably used for an inkjet recording method.
It goes without saying that it can also be used as a general writing instrument. Among the inkjet recording methods, it is particularly suitable when applied to an inkjet recording method of the type in which the ink is ejected by the bubbling phenomenon of the ink due to thermal energy.

An apparatus suitable for performing recording using the ink of the present invention is an apparatus which applies thermal energy corresponding to a recording signal to the ink in the chamber of the recording head and generates droplets by the thermal energy. To be An example of the device will be described below.

An example of the head structure, which is the main part, is shown in FIG.
This is shown in FIGS. The head 13 is a glass, ceramics, or plastic plate having a groove 14 through which ink passes, and a heating head 15 used for thermal recording.
(Thin film head is shown in the figure, but not limited to this). Heating head 1
Reference numeral 5 denotes a protective film 16 made of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate 20 having good heat dissipation such as alumina. Made of

The ink 21 is a discharge orifice (fine hole) 2
2, the meniscus 23 is formed by the pressure P.

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, and the pressure thereof is generated. Then, the meniscus 23 protrudes, the ink 21 is ejected, and becomes a recording droplet 24 from the orifice 22 and flies toward the recording material 25. FIG. 2 shows an external view of a multi-head in which a large number of heads shown in FIG. The multi-head includes a glass plate 27 having a multi-groove 26,
A heating head 28 similar to that described with reference to FIG.

Incidentally, FIG. 1A is a sectional view of the head 13 along the ink flow path, and FIG. 1B is a sectional view of FIG.
It is a cross section at line B.

FIG. 3 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 3, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to serve as a fixed end, which is in the form of a cantilever. The blade 61 is arranged at a position adjacent to the recording area by the recording head, and in the case of this example,
The recording head is held in a protruding form in the moving path of the recording head.
Reference numeral 62 denotes a cap, which is arranged 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 comes into contact with the ejection 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 constitute an ejection recovery unit 64, and the blade 61 and the absorber 63 remove water, dust, and dust on 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 65 mounted to move the recording head 65. It is a carriage for performing. 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 is a paper feed section for inserting a recording material, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to the position facing the ejection opening surface of the recording head, and is ejected to the ejection portion provided with the ejection roller 53 as the recording progresses.

In the above configuration, when the recording head 65 returns to the home position after recording is completed, the head recovery unit 64
The carriage 62 is retracted from the movement path of the recording head 65, but the blade 61 is projected in the movement path. As a result, the ejection port surface 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 moving 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 61 are in the same position as the above-mentioned position during wiping. As a result, even during this movement, the ejection port surface of the recording head 65 is wiped.

The above-mentioned 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. The wiper is moved to the position, and the wiping is performed along with the move.

FIG. 4 shows an ink cartridge 4 containing ink to be supplied to the head through an ink supply tube.
It is a figure which shows an example of 5. Here, 40 is an ink bag containing the supply ink, and a rubber stopper 42 is provided at the tip thereof.
Is provided. 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.

The ink jet recording apparatus used in the present invention is not limited to the above-described head and ink cartridge which are separate bodies, and those in which they are integrated as shown in FIG. 5 are also preferably used. To be

In FIG. 5, an ink cartridge 70 contains an ink absorber impregnated with ink, and the ink in the ink absorber has a head portion 71 having a plurality of orifices. It is configured to be ejected as an ink droplet from. Reference numeral 72 is an atmosphere communication port for communicating the inside of the cartridge with the atmosphere.

The ink jet cartridge 70 is
It is used in place of the recording head 65 shown in FIG. 3 and is detachable from the carriage 66.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, unless otherwise specified, the word "middle part" is based on weight.

[0040]

【Example】

Examples 1 to 6 The components shown in Table 1 were mixed, sufficiently stirred and dissolved, and then pressure-filtered with a fluoropore filter (trade name: manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 0.45 μm, The ink is an example of the present invention.

Comparative Examples 1 to 6 Each component shown in Table 2 was treated in the same manner as the ink of the example to obtain a comparative example of ink.

Next, using the inks of Examples 1 to 6 and Comparative Examples 1 to 6 obtained above, an on-demand type ink jet printer using a heating element as an ink discharge energy source was used as an ink jet recording apparatus. A printing test was conducted, and (1) color tone, (2) clogging property, (3) printing density, (4) bronze on recorded matter, (5) water resistance,
(6) Bleeding and (7) Evaluation of fixability were performed according to the following criteria. The evaluations obtained are shown in Tables 3 and 4.

(Evaluation Method and Evaluation Criteria) (1) Color Tone A solid portion was printed on SK paper (Canon NP Dry SK) with a printer, and the color tone was visually evaluated.

(2) Clogging property (fixing recovery property) The printer was left in a constant temperature bath at 35 ° C. for 1 month, and then left at room temperature for 24 hours to perform recovery operation (suction operation by pumping) and then print. The following criteria evaluated. ○: Return to normal printing state within 5 times of recovery operation △: Return to normal printing state within 6 to 10 times of recovery operation ×: No ejection or print disorder after 6 to 10 times of recovery operation

(3) Printing Density A solid part was printed on SK paper (Canon NP Dry SK) with a printer and naturally dried in a room for 24 hours, and its optical density was determined by Macbeth RD915 (trade name: Macbeth). And evaluated according to the following criteria. ◯: Printing density is 1.30 or more Δ: Printing density is 1.20 to 1.29 ×: Printing density is 1.19 or less

(4) A solid part was printed on SK paper (Canon NP Dry SK) with a bronze printer, allowed to stand for 1 hour or more, and visually evaluated for gloss of the solid part according to the following criteria. ◯: There is no gloss and the density is even and uniform. Δ: There is some gloss, unevenness and unevenness. X: The entire surface is glossy and uneven.

(5) Water resistance A solid part is printed on SK paper (Canon NP Dry SK) with a printer, left for 1 hour or more, and then vertically printed in still water.
It was dipped for 2 seconds, pulled up vertically as it was, and naturally dried in a room, and then the degree of redeposition property due to the outflow of the dye to the unprinted white portion was evaluated according to the following criteria. ◯: No re-dyeing and no stains Δ: Re-dyeing and slightly conspicuous ×: Severe re-dyeing and obvious stains

(6) Blurring After printing alphanumeric characters on SK paper with a printer and leaving it for 1 hour or more, the sharpness of the characters and the degree of the whisker-like bleeding generated from the characters were evaluated with a microscope and visually. ◯: Characters are sharp and do not have beard-like bleeding Δ: Characters are not sharp and slightly bleeding occurs ×: Characters are not sharp and have many bleeding

(7) Fixability A printer prints alphanumeric characters on SK paper,
After 25 and 30 seconds, the printed part was rubbed with a lens cleaning paper, and the number of seconds until the printed part was not stained was measured and evaluated according to the following criteria. ○: Within 15 seconds △: 16 to 25 seconds ×: 26 seconds or more

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

As described above, according to the ink of the present invention,
It has excellent water resistance when recorded on any recording material, especially so-called plain paper such as copy paper used in offices and homes, and has an ideal black color. In addition, it is possible to obtain an ink suitable for an inkjet ink having a high print density, a bleeding-free, high-quality recorded image, excellent dissolution stability, no nozzle clogging, and good storage stability. .

[Brief description of drawings]

FIG. 1A is a cross-sectional view illustrating a configuration example of a head according to the present invention. (B) is a cross-sectional view illustrating a cross section taken along line AB of FIG. 1- (a).

FIG. 2 is an external view illustrating a multi-head in which a large number of heads shown in FIG. 1- (a) are arranged.

FIG. 3 is a perspective view illustrating an inkjet recording apparatus incorporating the head of the present invention.

FIG. 4 is a cross-sectional view illustrating an example of an ink cartridge that stores ink supplied to a head via an ink supply tube.

FIG. 5 is a perspective view illustrating an example of an inkjet recording apparatus in which a head and an ink cartridge are integrated.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Katsura Castle Ryuji 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiko Tonogaki 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (72) Inventor Keiichi Murai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshifumi Hattori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (16)

[Claims] 1. An ink containing a colorant and a liquid medium which dissolves the colorant, wherein the colorant is at least one of dyes represented by the following structural formula (a): C.I. I. Acid Yellow 17: 1, C.I. I. Acid Yellow 23, C.I.
I. Acid Yellow 49, C.I. I. Acid Yellow 65, C.I. I. Acid Yellow 104, C.I. I. Acid Yellow 183, C.I. I. Acid yellow 15
5, C.I. I. Acid Yellow 194, C.I. I. Direct Yellow 86, C.I. I. Direct yellow 10
6, C.I. I. Direct Yellow 142, C.I. I. At least one yellow dye selected from Direct Yellow 194, the liquid medium contains at least one polyhydric alcohol and an aliphatic monohydric alcohol, and urea, ammonium salt of inorganic acid, and hydroxide. An ink characterized by containing. [Outer 1] 2. The ink according to claim 1, wherein the mixing ratio of the dye represented by the structural formula (a) and the yellow dye is in the range of 40: 1 to 4: 1 by weight. 3. The polyhydric alcohol is ethylene glycol, diethylene glycol, thiodiglycol, and
2. At least one selected from glycerin is included.
Ink described in. 4. The ink according to claim 1, which is for inkjet recording. 5. In an inkjet recording method for recording by ejecting ink as ink droplets, the ink contains a coloring agent and a liquid medium that dissolves the coloring agent, and the coloring agent has the following structural formula (a): ) And at least one of the dyes represented by I. Acid Yellow 17: 1,
C. I. Acid Yellow 23, C.I. I. Acid Yellow 49, C.I. I. Acid Yellow 65, C.I. I. Acid Yellow 104, C.I. I. Acid yellow 18
3, C.I. I. Acid Yellow 155, C.I. I. Acid Yellow 194, C.I. I. Direct Yellow 86,
C. I. Direct Yellow 106, C.I. I. Direct Yellow 142, C.I. I. Direct Yellow 194
At least one yellow dye selected from the above, the liquid medium contains at least one polyhydric alcohol and an aliphatic monohydric alcohol, and further contains urea, an ammonium salt of an inorganic acid, and a hydroxide. An inkjet recording method characterized by the above. [Outside 2] 6. The ink jet recording method according to claim 5, wherein the mixing ratio of the dye represented by the structural formula (a) and the yellow dye is in the range of 40: 1 to 4: 1 by weight. 7. The polyhydric alcohol is ethylene glycol, diethylene glycol, thiodiglycol, and
6. At least one selected from glycerin is included.
Inkjet recording method described. 8. The inkjet recording method according to claim 5, wherein the recording method is a method in which thermal energy is applied to eject the ink as ink droplets. 9. 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 any one of claims 1 to 3. Inkjet recording unit. 10. The recording unit according to claim 9, wherein the head portion includes a head that applies thermal energy to the ink to eject ink droplets. 11. An ink cartridge having an ink containing portion containing ink, wherein the ink is
An ink cartridge comprising the ink according to any one of claims 1 to 3. 12. An ink-jet recording apparatus comprising a recording unit having 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 any one of claims 1 to 3. An inkjet recording apparatus characterized by the following. 13. The ink jet recording apparatus according to claim 12, wherein the head portion includes a head that applies thermal energy to the ink to eject ink droplets. 14. An ink according to any one of claims 1 to 3, wherein an ink cartridge is provided with an ink containing portion containing ink and a recording head for ejecting the ink as ink droplets is used. An inkjet recording apparatus characterized by the following. 15. The ink jet recording apparatus according to claim 14, further comprising an ink supply unit that supplies the ink contained in the ink cartridge to the recording head. 16. The ink jet recording apparatus according to claim 14, wherein the recording head includes a head which applies thermal energy to ink to eject ink droplets.