JPH0912950A - Recording liquid and recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recording liquid excellent in water resistance, stick restorability and delivery stability, and capable of giving prints with high color development ad high deepness, containing an anionic dye with anionic group salt-formed by an alkali metal ion. SOLUTION: This recording liquid comprises an organic solvent, water and a carboxyl-contg. anionic dye with the anionic group bearing the form of salts selected from an alkali metal (including Li and Na) salt, ammonium salt, organic amine salt and alkanolamine salt and the alkali metal salt, ammonium or organic amine salt and alkanolamine salt accounting for 30-100%, 0-50% and 0-60% of the the number of the salt-formed anionic groups, respectively. The anionic dye is pref. a dye of formula I Pc is a metallophthalocyanine nucleus; R1 to R3 are each, an alkyl, etc.; X is carbonyl, of formula II [Z is NR4 R5 , SR6 (R4 to R6 are each H, an aralkyl, etc.), etc.], etc.; G is a COSH and/or COOH substituted colorless organic group; (t+q) is 3-4}.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid (hereinafter referred to as an ink) suitable for use in an ink jet system or a writing instrument in which droplets are ejected from an orifice of a recording head for recording, and a recording method using the same. Regarding

[0002]

2. Description of the Related Art Various types of ink jet recording methods have been actively researched because they produce little noise and can perform high speed recording without requiring special fixing on plain paper. The ink used in these inkjet recording methods has physical properties such as viscosity and surface tension within appropriate ranges, does not clog fine discharge ports, has a clear color tone, and has a sufficiently high density recorded image. Is required, and various properties such as physical property change during storage or precipitation of solid content are not required.

Further, in addition to these, as the requirements required for ordinary ink, it is possible to record without limitation on the type of recording material represented by paper, and the fixing speed to the recording material is high. It is also required that the recorded image formed on the recording material has excellent weather resistance, water resistance and abrasion resistance, and that it provides an image with excellent resolution. In particular, recorded images with water-soluble ink have poor water resistance,
When it gets wet with water, the printed matter disappears, bleeds, or is contaminated due to redeposition of the once-eluted dye, so that the image quality is deteriorated. Therefore, in the ink used in the ink jet recording method which normally uses a water-soluble ink, improvement of water resistance is a major issue among the above-mentioned required characteristics.

[0004]

In order to obtain a clear color tone and high density in such an ink jet recording system,
An ink containing a water-soluble dye as a pigment is effective, but a dye having a superior color tone and density has a problem in terms of water resistance. These problems can be solved, for example, by using a dye having a structure described in EP0468647A1. The characteristic of these dyes is that the solubility of the dye in water has pH dependency. That is,
As shown in the graph of FIG. 1 showing the relationship between the pH and the solubility of the dye, the solubility of the dye changes remarkably at the boundary of pH 5 to 7. Due to this property, when the ink containing these dyes is printed on the recording paper, the pH of the recording paper surface is in the almost acidic to neutral range, and the dye is placed in a pH environment where its solubility is remarkably reduced. In addition, even if tap water or rainwater whose pH is almost acidic to neutral touch the printed matter,
Prevents characters and images from flowing out, bleeding or discoloration,
Shows excellent water resistance.

However, the dye having such characteristics is inferior in re-solubility because the pH is naturally lowered when the ink is dried. Therefore, if the printer is left for a long time after printing is stopped, or if the ink tank and the head are separable, or if the ink tank is left unattended for a long time, the head tip Dye adheres to various nozzles and ink supply ports of ink tanks, causing clogging, which makes recovery difficult.

In order to solve such a problem, it is preferable to increase the solubility of the dye in the ink medium. As one means for achieving this, it is considered that the pH of the ink is raised to improve the re-dissolvability of the fixed ink. However, this method not only adversely affects the head, the main body and other members,
Since the solubility of the dye in water increases, the water resistance of the printed matter may decrease. In contrast to such a method, without increasing the pH of the ink, by increasing the solubility of the dye in an ink medium other than water, that is, an organic solvent, the dye does not precipitate as a solid content even after the water content of the ink evaporates. Is desirable. Although the above organic solvent is water-soluble, since it permeates and is retained in the recording material, the water resistance of the printed matter is hardly deteriorated. For that purpose, good water resistance can be maintained by changing the anionic group of the dye to an alkali metal salt, especially a Li salt or a non-volatile organic amine salt or an alkanolamine salt. Of these dyes, alkali metal salt dyes have improved solubility in organic solvents, but at the same time have increased solubility in water, so that the water resistance as an ink (printed matter) tends to relatively decrease. Further, since the dye which is made into an organic amine salt tends to have low solubility in water, the water resistance of the printed matter is good, but the solubility stability of the dye as ink is lowered. When an alkanolamine salt is used as a dye as compared with such a method, the solubility of the dye in water is almost unchanged and the solubility in an organic solvent is improved. The anti-sticking performance is improved without damaging.

However, in the recording method of the type in which thermal energy is applied to ink to eject it, when the above-mentioned triethanolamine chlorinated dye is used, it tends to burn on the heating element, which causes recording stability. However, there is a problem in that the print quality is deteriorated, and the nozzles are eventually clogged to cause ejection failure. Therefore, an object of the present invention is to solve the above problems, and to provide an ink and a recording method which provide a printed matter with high color development and high density, which is excellent in water resistance, fixation recovery, and ejection stability. .

[0008]

The above object is achieved by the present invention described below. That is, the present invention is an ink comprising at least an anionic dye, an organic solvent and water,
An alkali metal salt or ammonium salt in which the anionic dye has at least one carboxyl group and the anionic group of the anionic dye contains either Li or Na;
One of the organic amine salt and the alkanolamine salt, or two or more of them are in the form of a salt, and among the number of salt-forming anionic groups in one molecule of the dye, the alkali metal salt is 30 or more.
-100%, 0-50% of either ammonium salt or organic amine salt, and 0-60% of alkanolamine salt, and a recording method using the same.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION When the anionic dye is salted with only an alkanolamine to solve the above-mentioned problems of the prior art, the dye is apt to cause charring on the heating element. However, it has been found that the above charring can be prevented by forming a part of the anionic groups of the dye molecule with an alkali metal ion. The alkali metal salt of the dye has a property of deteriorating the water resistance of the printed matter as compared with the organic amine salt or the triethanolamine salt of the dye, but at the same time, an ammonium ion or an organic amine effective for waterproofing the dye is simultaneously added. By adjusting the kind of the salt quantitatively according to the molar ratio of the number of anionic groups per dye molecule, the deterioration of water resistance of the printed matter can be minimized, and the ink sticking recovery performance and the ejection can be improved. An ink having good stability and well-balanced performance was obtained. Further, since the anionic dyes of the following general formulas (2) to (4) which are preferably used in the ink of the present invention have a relatively large molecular weight, a large amount of the dye must be mixed in the ink in order to increase the color density of the ink. By doing so, the reliability of ink fixation and the reliability of ejection characteristics may be affected to a considerable extent. Therefore, in order to enhance the color developability and color density of the ink, an ink giving a clearer color tone and a high density image could be obtained by using an anionic dye having a lower molecular weight in combination.

Next, the present invention will be described in more detail with reference to preferred embodiments. The ink of the present invention is basically composed of a dye as a coloring material and a solvent,
An anionic dye is used as the dye, the anionic dye has at least one carboxyl group, and the anionic group of the anionic dye contains either Li or Na. In the form of any one or two or more of an amine salt and an alkanolamine salt, 30 to 100% of an alkali metal salt is an ammonium salt or an organic salt in the number of salt-forming anionic groups in one molecule of the dye. It is characterized in that any one of the amine salts accounts for 0 to 50% and the alkanolamine salt accounts for 0 to 60%.

As the anionic dye used in the present invention, the dyes represented by the following general formulas (2) to (4) are particularly preferable. _{Ar 1 -N = N-J-} X- (NR 1 -L-NR 2 -X) n -J-N = N-Ar 2 (2) { wherein, J is the following formula, Ar ₁ and Ar ₂ are each independently an aryl group or a substituted aryl group, and at least one of Ar ₁ and Ar ₂ is CO
It has at least one substituent selected from an OH group and a COSH group, R ₁ and R ₂ are independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group or a substituted alkenyl group, and L is a divalent group. Is an organic linking group, and n is 0 or 1.
And X is independently a carbonyl group or

The following formulas (I) to (III) [In the formula, Z is independently NR ₃ R ₄ , SR ₅ or OR ₅ , Y is independently hydrogen atom, chlorine atom, Z, SR ₆ or OR ₆ , and E is independently chlorine atom. Or a CN group, and R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted group. It may be an aralkyl group, or R ₃ and R ₄ together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring. ] The number of the groups selected from the COOH group and the COSH group in the compound (2) is at least the same as or more than the number of SO ₃ H groups. ｝

Pc (SO ₃ H) _t (SO ₂ —NR ₁ —L—NR ₂ —X—NR ₃ —G) _q (3) (wherein Pc is a phthalocyanine nucleus containing a metal, and R ₁ , R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group or a substituted aralkyl group, and L is 2
Is a valent linking group, X is independently a carbonyl group or the following formulas (IV) to (VI) [In the formula, Z is independently NR ₄ R ₅ , SR ₆ or OR ₆ , Y is independently hydrogen atom, chlorine atom, Z, SR ₇ or OR ₇ , and E is independently chlorine atom. Or a CN group, R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, or R
₄ and R ₅ together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring. ] It is a connecting group represented by, G is a colorless organic group substituted by 1 or 2 groups selected from COSH group and COOH group, and (t + q) is an integer of 3-4. . ｝

[0014] {In the formula, Ar and Ar ₁ are each independently an aryl group or a substituted aryl group, and at least _one of Ar and Ar ₁ has at least one substituent selected from a COOH group and a COSH group, J and J ₁ are independently

The following formulas (VII) to (IX) [Wherein R ₅ is independently selected from a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxyhalogen group, a CN group, a ureido group and an NHCOR ₆ group, and R ₆ is a hydrogen atom, an alkyl group, a substituted alkyl group, An aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, T is independently an alkyl group, W is independently a hydrogen atom, CN
Group, a CONR ₁₀ R ₁₁ group, a pyridinium group and a COOH group, m is a C ₂ -C ₈ alkylene chain, and B is
Is a hydrogen atom, an alkyl group or a COOH group, R ₁₀ ,
R ₁₁ is independently a hydrogen atom, an alkyl group or a substituted alkyl group. ] A linking group represented by, R ₁ , R ₂ ,
R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group or a substituted alkyl group, L is a divalent organic linking group, and n
Is a number of 0 or 1 and X is independently a carbonyl group or

The following formulas (X) to (XII) [In the formula, Z is OR ₇ , SR ₇ or NR ₈ R ₉ , Y is a hydrogen atom, a chlorine atom, a CN group or Z, E is a chlorine atom or a CN group, and R ₇ , R ₈ and R ₉ is independently a hydrogen atom, an alkenyl group, a substituted alkenyl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, or R ₈ and R ₉ are bonded to each other. A 5-membered ring or a 6-membered ring may be formed together with the nitrogen atom. ] It is a connecting group represented by. ｝

To salt the anionic group of the anionic dye as described above, each dye is made into a free acid type structure, and an alkali metal ion, ammonium ion, organic amine or alkanolamine is added to It is achieved by harmonizing. As such an alkali metal ion,
For example, sodium acetate, lithium acetate, potassium acetate, sodium carbonate, lithium carbonate, potassium carbonate, sodium hydrogen carbonate, lithium hydrogen carbonate, potassium hydrogen carbonate, sodium potassium hydrogen carbonate, sodium phosphate,
Of alkali metals such as potassium phosphate, disodium hydrogen phosphate, lithium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium tetraborate, lithium tetraborate, potassium tetraborate, sodium hydroxide, lithium hydroxide, potassium hydroxide, etc. It can be supplied by a weak acid salt or its hydrate or its hydroxide, but it is not particularly limited to this example. In addition, the proportion of these alkaline metal salts in the number of salt-forming anionic groups in one molecule of the dye is 30 to 100%, preferably 35 to 95%.
If it is less than 30%, the fixing recovery property is deteriorated, which is not preferable.

The ammonium ion as described above can be supplied, for example, by an ammonium compound such as ammonium hydrogensulfate, ammonium sulfate, and ammonia. As the organic amine, a water-soluble lower alkylamine such as methylamine, Methylamine hydrochloride, ethylamine, ethylamine hydrochloride, diethylamine, triethylamine, propylamine, propylamine hydrochloride, isopropylamine, isopropylamine hydrochloride,
It can be supplied by pentylamine, isopentylamine, isopentylamine hydrochloride, t-pentylamine, etc., but is not particularly limited to this example.
The proportion of these ammonium salts or organic amine salts in the number of salt-forming anionic groups in one molecule of the dye is 0 to 50%, preferably 5 to 45%. 50
If it is more than%, the ejection stability is deteriorated in addition to the sticking recovery property and the ink storage stability.

Further, similarly, as the alkanolamine, for example, monoethanolamine, diethanolamine, N, N'-diethanolamine, N-ethyldiethanolamine, triethanolamine, 2-amino-2.
-Ethyl-1,3-propanediol, 2-amino-1
-Butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, etc. can be used for supply, but the present invention is not limited to this example. The proportion of these alkanolamine salts in the number of salt-forming anionic groups in one molecule of the dye is 0 to 60%, preferably 5 to 45%.
It is. If it is more than 60%, kogation is likely to occur on the heater at the time of ink ejection, and ejection stability is deteriorated. The total amount of the above ammonium salt and alkanolamine salt is preferably 5 to 65% of the number of anionic groups in the dye.

The anionic dye characterizing the present invention as described above can be used alone, but other dyes can be further used in combination. Other preferable anionic dyes to be used in combination may be any of commercially available acid dyes, direct dyes and reactive dyes, and may be a combination of several kinds, but particularly C.I. I. Direct Blue 199, C.I. I. Direct Yellow 86 and the dye of the following general formula (1) are preferable because they have good color tone and density and there is no adverse effect due to the combined use of the dyes of the above general formulas (2) to (4).

[Wherein Y represents a hydrogen atom, a methyl group, a methoxy group, an acetylamino group or a nitro group,
Incidentally, a benzene ring may be formed together with the carbon atom at the 3-position of the benzene ring B. On the other hand, X represents any one of an acetyl group, a benzoyl group, a paratoluenesulfonyl group and a 4-chloro-6-hydroxy-1,3,5-triazin-2-yl group, and M ¹ , M ² and M ³ is a base independently selected from alkali metals, ammonium and amines. ]

The preferred solvent used for preparing the ink of the present invention is water or a mixed solvent of water and a water-soluble organic solvent, and particularly preferred is a mixed solvent of water and a water-soluble organic solvent. In addition, the water-soluble organic solvent contains a polyhydric alcohol having an ink drying preventing effect. 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 by mixing with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl. Alkyl alcohols having 1 to 4 carbon atoms such as alcohols; amides such as dimethylformamide and dimethylacetamide;
Ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol,
Alkylene glycols having an alkylene group of 2 to 6 carbon atoms, such as triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol; glycerin; ethylene glycol methyl (or ethyl) ether , Lower alkyl ethers of polyhydric alcohols such as diethylene glycol methyl (or ethyl) ether and triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 2 -Pyrrolidone and the like.

In the present invention, the ink is constituted by selecting an appropriate one from the above water-soluble organic solvents. In the case of the anionic dyes preferably used in the present invention as described above, the ink is particularly preferable. From the viewpoint of preventing clogging, diethylene glycol or thiodiglycol is preferable, from the viewpoint of image density and ejection stability, a nitrogen-containing cyclic compound or an ether compound of polyalkylene oxide is preferable, and further from the viewpoint of frequency response. The use of lower alcohols and surfactants is preferred. Therefore, a preferable 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 according to the present invention is generally 2 to the total weight of the ink.
It is in the range of 80% by weight, preferably 3 to 70% by weight, more preferably 4 to 60% by weight. The water used is 10 to 97.5% by weight of the total ink, preferably 35 to 9%.
It is 7.5% by weight, and more preferably 45-97.5% by weight.

The ink of the present invention prepared from such components as described above has various recording characteristics (for example, ink for writing instruments or ink for so-called ink jet recording).
Signal responsiveness, droplet formation stability, ejection stability, long-term continuous recording performance, ejection stability after long-term recording pause), storage stability, fixability on recording material, or formation It is a well-balanced and excellent color tone clearness of the recorded image, weather resistance, water resistance, alcohol resistance and the like. In order to further improve such characteristics, the ink of the present invention may further contain various conventionally known additives. Examples thereof include viscosity adjusting agents such as polyvinyl alcohol, celluloses and water-soluble resins; various cationic, anionic or nonionic surfactants, pH adjusting agents with buffer solutions, antifungal agents and the like.

Further, in order to prepare an ink used for an ink jet type of charging the ink, a specific resistance adjusting agent such as an inorganic salt such as lithium chloride, ammonium chloride and sodium chloride is added. When applied to an inkjet recording system of a type that ejects ink by the action of thermal energy, thermal physical property values (for example, specific heat, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

The ink of the present invention as described above is useful as a recording ink for various writing instruments, recording instruments and the like, and is particularly useful as an ink for an ink jet recording system. In this case, the inkjet method is
Any method may be used as long as the ink can be effectively separated from the nozzle and the ink can be applied to the recording material that is the range. The ink of the present invention has a viscosity at 25 ° C. of 1 to 20 cps, preferably 1 to 15 cps, and a surface tension of 20 dyn / cm or more, preferably 25 dyn / cm.
It is preferable that the material has a physical property of having a pH of about 4 to 10 and a cm or more.

The recording method in which the ink of the present invention is used is
An inkjet recording method is effective as a method, and as a recording material, any recording material such as general plain paper (for example, high-quality paper, medium-quality paper, bond paper), coated paper, plastic film for OHP, etc. But it can be used.
INDUSTRIAL APPLICABILITY The ink of the present invention is particularly suitable when applied to an inkjet recording method of the type that ejects ink due to the bubbling phenomenon of the ink due to thermal energy, and has the characteristic that ejection is extremely stable and satellite dots do not occur. is there. However, in this case, adjustment of thermal properties (for example, specific gravity, thermal expansion coefficient, thermal conductivity, etc.) may be required.

The ink of the present invention is particularly preferably used in an ink jet recording system in which droplets are ejected for recording by the action of heat energy, but it goes without saying that it can also be used as a general writing instrument. . The recording method of the present invention, which is suitable for recording using the ink of the present invention, is an inkjet recording method in which thermal energy corresponding to a recording signal is applied to the ink in the chamber of the recording head, and droplets are generated by the energy. is there. A recording apparatus to which such an inkjet recording method of the present invention is applied will be described below.

An example of the head configuration, which is the main part of the apparatus,
It is shown in FIGS. 2, 3 and 4. The head 13 includes a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heat generating head 15 used for thermal recording (a thin film head is shown in the figure, but is not limited to this). And obtained by bonding. The heating head 15
It is composed of a protective film 16 formed of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 formed of nichrome or the like, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina. There is.

The ink 21 is a discharge orifice (fine hole) 2
2, and the meniscus 23 is formed by the pressure P. Now, when electrical signal information is applied to the aluminum electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 rapidly heats up, and bubbles are generated in the ink 21 in contact with the area, and the pressure causes The meniscus 23 protrudes, the ink 21 is ejected and becomes an ink droplet 24, which is ejected from the ejection orifice 22 toward the recording material 25.

FIG. 4 shows an external view of a multi-head in which a large number of the heads shown in FIG. 2 are arranged. The multi-head is manufactured by closely adhering a glass plate 27 having multi-grooves 26 and a heating head 28 similar to that described in FIG. 2 is a cross-sectional view of the head 13 along the ink flow path,
FIG. 3 is a sectional view taken along the line AB of FIG.

FIGS. 6A and 6B are examples of perspective views of the ink tank recording chip integrated cartridge 809 provided in the ink jet recording apparatus used in the present invention, and FIG. 5 is this cartridge. 8 shows a perspective view of an ink jet recording apparatus equipped with 809.

In FIG. 5, 809Y, 809M, 809
C, 809Bk (these are collectively referred to as "cartridge 809", and the corresponding parts in each cartridge are denoted by the same numbers as "Y", "M", "C" and "Bk".
(The reference numerals with the reference numerals are used) are the cartridges shown in FIG. This cartridge 809 is used for the carriage 5
15 are fixed on the shaft 15 and can reciprocate in the longitudinal direction along the shaft 521. Positioning with respect to the carriage 515 can be performed by, for example, a hole 605 provided in the recording head 600 shown in FIG. 6B and a dowel provided on the carriage 515 side. Further, the electrical connection is performed by the recording head 600 shown in FIG.
A method in which a connector on the carriage 515 is coupled to a connection pad provided on a wiring substrate (not shown) for the ejection portion 602 of FIG. 1 or a contact for a cartridge connector is formed is used.

The discharge port 602A of the cartridge 809 is
For example, it is manufactured from 128 nozzles, and 63.
They are arranged at a pitch of 5 μm. The ink ejected from the ejection port 602A reaches the recording medium 518 whose recording surface is regulated by the platen roller 519 at a minute distance from the recording head 600 and forms an image. Recording head 60
To 0, an ejection signal according to image data is appropriately supplied from a data supply source (not shown) via the cable 516 and a terminal connected to the cable. The cartridge 809 is
Depending on the ink color used, one or more (4 in the figure
Can be installed.

Further, in FIG. 4, 517 is a carriage 5.
A carriage motor 522 for operating 15 along the shaft 521 is a wire for transmitting the driving force of the motor 517 to the carriage 515. Also, 520
Is coupled to a platen roller 519 to form a recording medium 518.
It is a feed motor for transporting. In the apparatus of this example, the ink tank 700 is the recording head 600.
It is a cartridge type that is integrally configured with the ink absorber (not shown) in the cartridge 809.
The ink that has been impregnated and retained in the recording head 600 is supplied into the recording head 600.

Here, referring to FIG. 6B, the recording head 600 is composed of an ejection port 602, a supply tank section 604 and the like. The ejection unit 602 includes an ejection port 602A formed on a surface facing a recording medium and a liquid path extending inward, for example,
As an example of using heat energy as discharge energy, it has a recording heater as a discharge energy generator such as an electrothermal converter arranged in the liquid passage, and a common liquid chamber communicating with each liquid passage. There is. Also, the supply tank unit 604
Functions as a sub-tank that receives the ink supply from the ink tank 700 side and guides the ink to the common liquid chamber in the ejection unit 602. The ink absorber 702, which is disposed in the ink tank 700 and is impregnated with ink, can be formed using a porous body, fibers, or the like.

[0039]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. First, the inks of Examples 1 to 9 of the present invention were prepared using the components shown in Table 1 below. Also, the inks of Comparative Examples 1 to 9 were prepared using the components shown in Table 2 below.

Table 1: Components of the inks of the examples

[0041]

[0042]

Table 2: Components of the ink of the comparative example

[0044]

[0045] * Here, "dye" means the general formula (2) in the claims.
It refers to those having the structures of (3) and (4).

The compounds of structural formulas (a) to (g) in Tables 1 and 2 are as shown below. Structural formula (a) Structural formula (b) Structural formula (c) Structural formula (d)

Structural formula (e) Structural formula (f) Structural formula (g)

[Evaluation] The inks of Examples and Comparative Examples of the present invention comprising the ink components shown in Tables 1 and 2 above were prepared.
An on-demand type multi-head (orifice size 50 × 40 μm, drive voltage 30 V, which applies thermal energy to ink in the recording head to generate droplets for recording,
The printing performance, the ejection performance, and the storage stability were evaluated when the printing was carried out by mounting it on a recording device having a frequency of 4 kHz. The contents and conditions of each evaluation item are as follows. The evaluation results are shown in Tables 3 and 4 below. Recording materials are Canon NP-6150 recommended paper, Xerox 4024 paper and Proberbond paper.

Discharge stability 100 sheets of continuous slip paper were printed and evaluated according to the following criteria. ：: No abnormality. X: Non-ejection or print disorder occurred. Clogging (fixing recovery property) After left for 1 month in an environment of 35 ° C., recovery operation (suction operation by pumping) was performed, printing was performed, and evaluation was performed according to the following criteria. ◯: The normal printing state is restored within 5 times of the recovery operation. X: No ejection or print disorder occurs even after the recovery operation is performed 6 times or more.

Water resistance [0050] A patch is prepared by printing on the above-mentioned recording material by simultaneously driving all nozzles, and after allowing it to naturally dry in a room for 24 hours, tap water is put in a petri dish and the patch is quietly placed. The sample was dipped in, and allowed to stand for 5 minutes, and then dried. -1 Remaining rate of optical density of the patch before and after immersion (optical density of patch after immersion / optical density of patch before immersion ×
100;%) was calculated and evaluated according to the following criteria. Good: The optical density residual rate is 50% or more. X: The optical density residual rate is less than 50%. -2 The degree to which the dye in the printed portion of the paper flows out and redeposits on the white background is evaluated according to the following criteria. ○: Contamination is not noticeable. X: Contamination is remarkable.

Storage stability Each of the inks obtained in Examples and Comparative Examples was placed in a Teflon sealed container in an amount of 100 cc, stored in a constant temperature bath at 60 ° C. for 1 month, and printed on a continuous slip paper. Evaluated. ：: No abnormality. X: No ejection, disordered printing, or discoloration occurred.

Table 3: Evaluation results of Examples and Comparative Examples

[0053]

As described above, according to the preferred embodiment of the present invention, the anionic dye contained in the ink always has the structure of any one of formulas (2), (3) and (4). And the anionic group in the dye is in the form of any one or two or more of an alkali metal salt containing any of Li and Na, an ammonium salt, an organic amine salt, and an alkanolamine salt, Of the number of salt-forming anionic groups per dye molecule, an alkali metal salt accounts for 30 to 100%, an ammonium salt or an organic amine salt accounts for 0 to 50%, and an alkanolamine salt accounts for 0 to 60%. As required, C.I. I. Direct Yellow 86, C.I. I. By using Direct Blue 199 and a dye having the structure of the general formula (1) in combination, it is possible to obtain an image having excellent color tone and density and good water resistance, which are excellent in fixing recovery, ejection stability, and storage stability of ink. Was completed.

[0054]

[Brief description of the drawings]

FIG. 1 is a graph showing the solubility of a dye with respect to pH.

FIG. 2 is a schematic cross-sectional view of a recording head according to the inkjet recording method used in the present invention.

FIG. 3 is a schematic cross-sectional view showing a contact cross section taken along the line AB of FIG.

FIG. 4 is a schematic external view showing an example of a multi-head in which many heads of FIG. 1 are arranged.

FIG. 5 is an internal mechanism diagram of an inkjet recording apparatus to which the ink and inkjet recording method of the invention are applied.

FIG. 6 is a perspective view of a cartridge-type recording head to which the ink and the inkjet recording method of the invention are applied.

[Explanation of symbols]

 13: Head 14: Ink Groove 15: Heating Head 16: Protective Film 17: Aluminum Electrode 18: Heating Resistor Layer 19: Heat Storage Layer 20: Substrate 21: Ink 22: Discharge Orifice (Fine Hole) 23: Meniscus 24: Small Ink Droplet 25: Recording material 26: Multi-slot 27: Glass plate 28: Heating head 515: Carriage motor 516: Cable 517: Carriage 518: Recording medium 519: Platen rotor 520: Feed motor 521: Shaft 522: Wire 600: Recording head 602: Ejection part 602A: Ejection port 604: Supply tank part 605: Hole 700: Ink tank 702: Ink absorber 809: Cartridge 809Y: Yellow cartridge 809M: Magenta cartridge 809C: Cyan cartridge 809 k: black cartridge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kumiko Manafune 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoshi Nagashima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (9)

[Claims] 1. A recording liquid comprising at least an anionic dye, an organic solvent and water, wherein the anionic dye has at least one carboxyl group, and the anionic group of the anionic dye is either Li or Na. In the form of one or more of any one of an alkali metal salt containing ammonium, an ammonium salt, an organic amine salt, and an alkanolamine salt, the number of salt-forming anionic groups in one molecule of the dye is an alkali metal salt. A recording liquid comprising 30 to 100% of a salt, 0 to 50% of an ammonium salt or an organic amine salt, and 0 to 60% of an alkanolamine salt. 2. The anionic dye comprises another anionic dye, and the other anionic dye is C.I. I. Direct Blue 199, C.I. I. The recording liquid according to claim 1, which is an anionic dye selected from Direct Yellow 86 and a dye having a structure of the following general formula (1). [In the formula, Y represents a hydrogen atom, a methyl group, a methoxy group, an acetylamino group or a nitro group, and may form a benzene ring together with the carbon atom at the 3-position of the benzene ring B. On the other hand, X is an acetyl group, a benzoyl group, a paratoluenesulfonyl group or 4-chloro-6-hydroxy-
Represents any of 1,3,5-triazin-2-yl groups,
M ¹ , M ² and M ³ are each independently a base selected from alkali metals, ammonium and amines. ] 3. An anionic dye is represented by the following general formula (2):
The recording liquid according to claim 1, which is a dye having any one of the structures (3) and (4). _{Ar 1 -N = N-J-} X- (NR 1 -L-NR 2 -X) n -J-N = N-Ar 2 (2) { wherein, J is the following formula, Ar ₁ and Ar ₂ are each independently an aryl group or a substituted aryl group, and at least one of Ar ₁ and Ar ₂ is CO
It has at least one substituent selected from an OH group and a COSH group, R ₁ and R ₂ are independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group or a substituted alkenyl group, and L is a divalent group. Is an organic linking group, and n is 0 or 1.
And X is independently a carbonyl group or the following formula (I)
(III) [In the formula, Z is independently NR ₃ R ₄ , SR ₅ or OR ₅ , Y is independently hydrogen atom, chlorine atom, Z, SR ₆ or OR ₆ , and E is independently chlorine atom. Or a CN group, and R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted group. It may be an aralkyl group, or R ₃ and R ₄ together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring. ] The number of the groups selected from the COOH group and the COSH group in the compound (2) is at least the same as or more than the number of SO ₃ H groups. _{} Pc (SO 3 H) t} (SO 2 -NR 1 -L-NR 2 -X-NR 3 -G) q (3) { wherein, Pc is a phthalocyanine nucleus containing metal, R _1, R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group or a substituted aralkyl group, and L is 2
Is a valent linking group, X is independently a carbonyl group or the following formulas (IV) to (VI) [In the formula, Z is independently NR ₄ R ₅ , SR ₆ or OR ₆ , Y is independently hydrogen atom, chlorine atom, Z, SR ₇ or OR ₇ , and E is independently chlorine atom. Or a CN group, R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, or R
₄ and R ₅ together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring. ] It is a connecting group represented by, G is a colorless organic group substituted by 1 or 2 groups selected from COSH group and COOH group, and (t + q) is an integer of 3-4. . ｝ {In the formula, Ar and Ar ₁ are each independently an aryl group or a substituted aryl group, and at least _one of Ar and Ar ₁ has at least one substituent selected from a COOH group and a COSH group, J and J ₁ are independently the following formulas (VII) to (IX) [Wherein R ₅ is independently selected from a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxyhalogen group, a CN group, a ureido group and an NHCOR ₆ group, and R ₆ is a hydrogen atom, an alkyl group, a substituted alkyl group, An aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, T is independently an alkyl group, W is independently a hydrogen atom, CN
Group, a CONR ₁₀ R ₁₁ group, a pyridinium group and a COOH group, m is a C ₂ -C ₈ alkylene chain, and B is
Is a hydrogen atom, an alkyl group or a COOH group, R ₁₀ ,
R ₁₁ is independently a hydrogen atom, an alkyl group or a substituted alkyl group. ] A linking group represented by, R ₁ , R ₂ ,
R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group or a substituted alkyl group, L is a divalent organic linking group, and n
Is a number of 0 or 1 and X is independently a carbonyl group or the following formulas (X) to (XII) [In the formula, Z is OR ₇ , SR ₇ or NR ₈ R ₉ , Y is a hydrogen atom, a chlorine atom, a CN group or Z, E is a chlorine atom or a CN group, and R ₇ , R ₈ and R ₉ is independently a hydrogen atom, an alkenyl group, a substituted alkenyl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group, or R ₈ and R ₉ are bonded to each other. A 5-membered ring or a 6-membered ring may be formed together with the nitrogen atom. ] It is a connecting group represented by. ｝ 4. An ink jet recording method for recording on a recording material by ejecting the recording liquid from an orifice according to a recording signal, wherein the recording liquid is the recording liquid according to claim 1. Recording method. 5. The recording method according to claim 4, wherein heat energy is applied to the recording liquid to eject the liquid droplets. 6. A recording method for recording on a recording material by ejecting the recording liquid from an orifice according to a recording signal, wherein the recording liquid is the recording liquid according to claim 2. Method. 7. The recording method according to claim 6, wherein thermal energy is applied to the recording liquid to eject droplets. 8. A recording method for recording on a recording medium by ejecting the recording liquid from an orifice according to a recording signal, wherein the recording liquid is the recording liquid according to claim 3. Method. 9. The recording method according to claim 8, wherein thermal energy is applied to the recording liquid to eject droplets.