JPS62190273A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a recording liquid composed of a specific phthalocyanine dye and a liquid medium, especially suitable for ink jet recording, having excellent long-term stability and ink-fixability and giving a recorded image having excellent definition, light-resistance, water-resistance, etc. CONSTITUTION:The objective recording liquid can be produced by compounding (A) a compound of formula I (Pc is phthalocyanine skeleton having coordinated Cu, Fe, Co, Ni, Mg, Sn, Zn or Mn as center atom or free from coordinated metallic atom; M is alkali metal, ammonium or organic amine; m is 2-3; n is 1-2) (e.g. the compound of formula II, etc.), (B) a liquid medium for dissolving or dispersing the compound and, if necessary, (C) various additives. The content of the compound of formula I is preferably 1-10(wt)% based on the whole ink composition. The liquid medium is preferably a mixture of water and a water-soluble organic solvent (e.g. diethylene glycol) and the amounts of water and the organic solvent are preferably 20-70% and 20-50% based on the whole ink composition, respectively.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a new recording liquid (hereinafter referred to as ink), and in particular, ink is ejected from fine ejection ports (ejection orifices) provided in a recording head, and the ink is The present invention relates to an ink suitable for a method of recording by flying droplets.

(Conventional technology) Traditionally, writing methods (fountain pens,
(Felt-tip pens, etc.) use inks prepared by dissolving various dyes 4 in water or other organic solvents.

Also, in the 4'1 inkjet system, where recording is performed by ejecting ink in the recording head from the ejection orifice using vibrations caused by a piezo vibrator or a static 1L gravity cap caused by the application of high voltage, there are various '! Ink is used by dissolving 1, 2, and 2 in water or organic solvents, etc. However, compared to ink for stationery such as general fountain pens and felt-tip pens, inkjet ink has many characteristics that require stricter conditions. is required.

Such an inkjet method is a method in which ink droplets (so-called ink) are ejected and are energized onto a recording material to perform recording. The basic components of such ink are a recording agent (Used as dye 1 or Kao I) and a liquid medium for dissolving or dispersing it (Used as water, various organic solvents, or mixtures thereof). Various additives are added accordingly.

(Problems to be Solved by the Invention) Conventionally, as this type of ink, for example, Japanese Patent Publication No. 50-8361,
Special Publication No. 51-40484, Special Publication No. 52-1312
Publication No. 6, Japanese Patent Publication No. 52-13127, Japanese Patent Application Publication No. 1973
As shown in Japanese Patent No. 95008, there are known dyes or pigments in which various dyes or pigments are dissolved or dispersed in aqueous or non-aqueous solvents. The preferable conditions for this type of ink are (1) liquid physical properties (viscosity, surface tension, conductivity, etc.) that match the ejection conditions (piezoelectric element drive voltage, drive frequency, orifice shape and material, orifice diameter, etc.); (2) be stable for long-term storage and not cause clogging of fine ejection ports or pores; (3) be recording material (paper,
(4) The color tone of the printed image should be clear and the density should be high. (5) The water resistance and light resistance of the printed image. (6) It does not corrode materials surrounding the ink (container, connecting tube, sealing material, etc.); (7) It has excellent safety characteristics such as odor, toxicity, and flammability. (8) The recording liquid used in the above-mentioned apparatus that generates droplets by applying thermal energy to the recording liquid has high thermal stability.

It is extremely difficult to simultaneously satisfy the various properties listed in L. The prior art described above was unsatisfactory in this respect.

Since the ink used for recording for such purposes is basically composed of a dye and its liquid medium, the above-mentioned ink characteristics are largely influenced by the inherent properties of the dye.

Therefore, selecting a dye so that the ink has two characteristics is an extremely important technique in this technical field.

Thus, the present invention was completed by finding a dye suitable for the ink used in the above-mentioned method as a result of extensive research.

(Disclosure of the Invention) That is, the present invention provides a recording liquid containing a recording agent which is a component for forming a recorded image and a liquid medium for dissolving or dispersing this recording agent, which is a recording agent represented by the following general formula (A). This is a recording liquid characterized by containing at least one dye represented by:

However, Pc in the formula is Cu, Fe, C as a central atom.
o, indicates a phthalocyanine skeleton coordinated with any of Ni, Mg, Sn, Zn or Mn, or a metal-free phthalocyanine skeleton that does not coordinate a metal atom, and M is selected from alkali metals, ammonium and organic amines. Indicates any one salt, (, m indicates a number of 2 to 3,
n represents a number of 1 to 2.

[Next, the present invention will be explained in more detail] Then, in order to achieve the above-mentioned object of the present invention, the present inventor conducted detailed research on Dye Nene 1, which is a recording agent component of ink, and found that a specific Phthalocyanine dyes are suitable as ink recording agents, especially ink recording agents used in inkjet systems, and by employing such specific phthalocyanine dyes as ink recording agents, inkjet systems can be used. When used, the liquid properties matched to the ejection conditions, long-term storage stability, ink stability for recording materials, image clarity, high density images, image light resistance, water resistance, and other required M functions are met. It was discovered that a satisfactory ink could be obtained.

The dye represented by the general formula (A) used in the present invention and mainly characterizing the present invention is the dye represented by the general formula (A) above.
Any dye may be used as long as it is included in the above, but particularly preferred examples of the conjugate include the following.

Illustrative example L cup ヱ sex m 虻糎j 舛ffl thing j sex work” Δ! A specific dyeing agent represented by the general formula (A), such as Tudanson.
By using l as an ink recording agent, the physical property values such as viscosity and surface tension are within the appropriate range, and it does not clog the fine ejection orifice, provides a high density recorded image on the top, and is heat resistant. It has high physical stability, does not cause changes in physical properties or precipitation of solid content during storage, can record on a variety of materials without limiting the type of recording material, has a fast fixing speed, and has high resistance to water and dirt. Ink 71) is produced that has excellent wear resistance and high resolution to produce desired images.

Any of the dyestuffs represented by the general formula (A), such as ``Ilf'', can be used in ``1''1, and has remarkable effects as shown below, but in the present invention, especially Ilf. Dye No. 1 is based on the general formula (A), where the number of sulfonic acid groups (-3O3M) in the molecule and the number of sulfonic acid groups (-3O3M), (
(-S 02 NH2), for example, m in the general formula (A) is 2 to 3 and n is 1 to
2. By balancing the numbers of m and n, dye l can be sufficiently and stably dissolved in the liquid medium, and there will be no precipitation even if the ink is stored for a long time. There is a growing risk of clogging at the tip of the recording head's orifice during recording. Moreover, by setting m and n in such a range, the water resistance of the formed image can be maintained sufficiently high. On the other hand, m and n
If the balance in the number of is disrupted, the dissolution stability of the dye will decrease, and the water resistance of the recorded image will decrease.

Further, when the dye of general formula (A) is a metal phthalocyanine, it is preferable that the concentration of free metal ions, such as copper ions, in the ink is 5 ppm or less; In particular, a method in which droplets are ejected by applying thermal energy is not preferable because it may cause the print head to stop ejecting.

The content of the above-mentioned dye is determined depending on the type of liquid medium component, the characteristics required of the ink, etc., but generally it is 0.1 to 20% by weight based on the total weight of the ink.
Preferably 0.5 to 15%, more preferably 1 to 10%
% range.

Of course, the dye can be used alone or in combination of two or more,
Alternatively, the dyeing dye 4 may be used as an essential component, and other dyeing dyes 1 and various dyeing dyes 1 such as acid dyes may be used in combination.

A suitable solvent for use in the ink is water or a mixed solvent of water and a water-soluble organic solvent, and a particularly suitable solvent is a mixed solvent of wood, water-soluble + 1 organic solvent, and a water-soluble 1) Contains a polyhydric alcohol having an effect of preventing ink from drying as an organic solvent. Further, as water, it is preferable to use deionized water rather than ordinary water containing various ions. Examples of water-soluble organic solvents used in combination with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 5ec-butyl alcohol, tert-butyl alcohol, and isobutyl alcohol. Alkyl alcohols with 1 to 4 carbon atoms; amides such as dimethylformamide and dimethylacetamide; ketone or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol and polypropylene glycol Recalls: Alkylene groups containing 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1゜2.6-hexandriol, thiodiglycol, hexylene glycol, diethylene glycol, etc. Alkylene glycols; glycerin;
ethylene glycol methyl (or ethyl) ether,
Lower alkyl ethers of polyhydric alcohols such as diethylene glycol methyl (or ethyl) ether and I-lyethylene glycol methyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1,3-dimethyl-
Examples include 2-imidasolidinone. Among these many water-soluble organic solvents, polyalcohols such as diethylene glycol, triethylene glycol monomethyl (
Or ethyl) lower alkyl ether of polyhydric alcohol such as ether is l! It's frightening.

The content r11 of the above-mentioned water-soluble organic solvent in the ink is generally 5 to 95 weight J■ with weight Ji 1% based on the total weight of the ink.
j%, preferably from 10 to 80% by weight, more preferably from 20 to 50% by weight.

The water content at this time is determined within a wide range depending on the type of the solvent component, its composition, and the desired characteristics of the ink, but it is generally 10-90% of the total weight of the ink.
%, preferably 10-70%, more preferably 20-7
It is considered to be within the range that accounts for 0%.

The ink of the present invention, which is formulated from such components, has excellent recording properties (signal response, stability of droplet formation, ejection stability, long-term continuous recording, ejection after a long recording pause). Stability) Storage stability, stability to recording materials, light resistance of recorded images, anti-fog resistance, water resistance, etc. are all well-balanced and excellent. In order to further improve such properties, various conventionally known additives may be added to the composition.

Viscosity modifiers such as side light, polyvinyl alcohol, celluloses, and water-soluble resins; Surface tension modifiers such as cationic, anionic, or nonionic surfactants, jetanolamine, triethanolamine, etc.; pH adjustment using buffer solutions. Conditioners, fungicides, etc. can be mentioned.

Furthermore, in order to formulate ink used in an inkjet system that charges the ink, resistivity adjusters such as inorganic salts such as lithium chloride, ammonium chloride, and chloride are added.

Note that when applied to an inkjet system in which ink is ejected by the action of thermal energy, thermal physical property values (eg, specific heat, thermal expansion coefficient, thermal conductivity $) may be adjusted.

The ink of the present invention as described below is useful as a recording ink for various writing instruments, recording instruments, etc., and is particularly useful as an ink for ink jets and inks.

To explain the case of an inkjet method as a preferable example, this inkjet method can be used in any method as long as it is a method that effectively releases ink from a nozzle and delivers ink to a recording material, which is a projectile. A typical example of these methods is, for example, IEEE Trans Actions on Industry Applications (IEEE Trans Actions on Industry Applications).
tions onIndustry Applic
ations) Vol.A-13, No. 1 (19
(February/March 1977 issue), 11th Kei Electronics 197
6, 4JJ19 [No. 1, January 29, 1973 [No. 1] and May 1974, No. 60. The methods described above are suitable for use with the ink of the present invention.To explain some of them, there is an electrostatic suction method.In this method, nozzles and accelerated There is a method in which a strong electric field is applied between the ink particles and the nozzle, and the ink is drawn out one after another from the nozzle, and an information signal is given to the deflection electrodes while the drawn ink flies between the deflection electrodes to record the ink particles. There is a method of ejecting ink droplets in response to an information signal without deflection, and either method is effective for the ink of the present invention.

The second method is to forcibly eject minute ink particles by applying high pressure to the ink with a small pump and mechanically vibrating the nozzle with a crystal oscillator. At the same time as the injection, it is charged according to the information signal. the law of nature;? When the charged ink particles pass between the deflection electrode plates, they are deflected according to the charging force 11. Another method using this method is called the microdot inkjet method. In this method, the ink pressure and excitation line 1 are kept within a certain range of appropriate 4fi, and one type of ink liquid of one size or smaller is ejected from the nozzle tip. Droplets are generated, and only the small and medium-sized droplets are used for recording. The feature of this method is that it is possible to obtain a group of minute droplets even with a conventionally large nozzle diameter.

A third method is a piezo element method, in which a piezo element is used as a pressure means for applying pressure to the ink, rather than a mechanical means such as a pump as in other methods. This method applies an electric signal to a piezo element to cause mechanical displacement, thereby applying pressure to the ink and ejecting it from a nozzle.

In addition, an inkjet method is disclosed in Japanese Patent Application Laid-Open No. 54-51837, in which ink subjected to the action of thermal energy undergoes a sudden change in volume, and the acting force due to this state change causes the ink to be ejected from a nozzle. can also be used effectively.

The ink of the present invention as described in [1] above employs a specific phthalocyanine dye 1 as its recording agent, so it can be used not only as an ink for general recording, but also as an ink for use in inkjet systems in particular, and has long-term storage properties. It has recording characteristics of stable I, ejection stability, and ejection response of 1st class, and when applied to a recording material, it exhibits +U ink fixing properties, and in particular, it has excellent ink fixability of 1. It is possible to record images with excellent water repellency, sharpness, resolution, etc.

Next, the present invention will be explained more comprehensively by giving Examples and Comparative Examples. In the text, parts and percentages are based on weight unless otherwise specified.

Example 1 Dyeing of Exemplified Compound (1) (m=3, n=1) 5 parts diethylene glycol 30 parts N-methyl-2-pyrrolidone 15 parts water
50 parts of the composition were thoroughly mixed and dissolved in a container, filtered under pressure through a Teflon filter with a pore size of 1 μm, and then degassed using a vacuum pump to obtain the ink of the present invention. 1) Using the ink, the ink is ejected by a piezo vibrator for on-demand recording (ejection orifice diameter: 507 mm,
When the following studies (T1) to (T5) were conducted using a recording device having a piezo vibrator drive voltage of 60 V and a frequency of 4 KHz, good results were obtained in all cases.

(T1) Long-term storage stability of the ink: Even after the ink was sealed in a glass container and stored at -30°C and 60°C for 6 months, no precipitation of insoluble matter was observed, and there were no changes in the physical properties or color tone of the liquid. There wasn't.

(T2) Ejection stability: Continuous ejection was performed for 24 hours in an atmosphere of room temperature, 5° C., and 40° C. Under all conditions, stable high-quality recording was possible from beginning to end.

(T3) Ejection response: Intermittent ejection every 2 seconds and ejection after being left for 2 months were investigated, and in both cases, there was no clogging at the tip of the orifice, and recording was stable and uniform.

(T4) Quality of recorded images: The images recorded on the recording materials shown in the table below had high density and were clear. The rate of decrease in density after three months of exposure to room light was less than 1%, and when immersed in water for 1 minute, there was very little blurring of the image.

(T5) Fixed foil properties for various recording materials: Printing was performed on the recording materials listed in the table below, and after 15 seconds, the printed area was rubbed with a finger to determine the presence or absence of image shift and bleeding. All of them exhibited excellent fixing properties with no image shift or bleeding.

1 company MAL system - minute 11bu - Manufacturer silver
Tamaki Ka Paper Sanyo Kokusaku Valve ■Seven Stars Volume 1
Quality Paper Hokuetsu Paper - White Botanchu Quality Paper Honshu Paper ■ Toyo Roshi No. 4 Non-size paper Toyo Filter Paper ■ Example 2 Exemplary Compound (4) Dye (m = 2, n = 2) 6 parts Diethylene glycol 25 parts Water
69 parts Example 1
The ink of the present invention having the above composition was prepared in the same manner as above, and an on-demand type multi-head (discharge orifice diameter 35 gm, heating resistor Resistance value 150Ω,
(TI) to (T5) were investigated in the same manner as in Example 1 using a recording device with a drive voltage of 30 V and a frequency of 2 K), but excellent results were obtained in all tests Δ・1. .

Example 3 Exemplary Compound (3) Dyeing $4 (m=3, n=2) 4 parts diethylene ethylene glycol 25 parts N-methyl-2-pyrrolidone 20 parts water
51 parts An ink with the above composition was prepared in the same manner as in Example 1.

This ink was filled into a felt tube and
): Honshu Paper Industries) to examine water resistance and writability after removing the cage and leaving it for 24 hours. The ink of this example had excellent water resistance and writability after standing.

Examples 4 to 14 Inks of the present invention having the compositions listed in Table 1 below were prepared in the same manner as in Example 1, and in the same manner as in Example 2 (
TI) to (T5) were investigated. These inks gave good results in terms of long-term storage, recording performance, fixation of recorded images, clarity, etc. The number next to the dye indicates the fragrance i1 of the above-mentioned exemplified compound.

f′! ;1-----7 Example 4 Somesai'12 (m=3, n=1)
5FCR diethylene glycol 30 parts water
65 copies Example 5 Dye 14 (m=2, n=1)
5RR ethylene glycol
30 parts polyethylene glycol (Mw
t, 200) 5 parts water
6o parts Example 6 Dye 6 (m=2, n=2) 5 parts diethylene glycol 20 parts N-methyl-2
-pyrrolidone 15 parts water
59 parts Example 7 Dye 8 (m=3, n=2) 4 parts diethylene glycol 20 parts N-methyl-2
-pyrrolidone 15 parts water
61 parts Example 8 Dye 5 (m=3, n=2) 5 parts diethylene glycol 30 parts triethylene glycol monomethyl ether 10 parts water
55 parts (free #, copper ion concentration 4.6 pp intestine) Example 9 Dye 5 (m=2, n=1) 6 parts ethylene glycol 25 parts 1,3-dimethyl-2-imidazolidinone 10 parts water
59 parts (M# copper ion concentration 3.8) Example 1O Dye 9 (m=2, n=1) 4 parts diethylene glycol 25 parts N-methyl-
2-pyrrolidone 15 parts water
56 parts (M detuned ion concentration 4.1 ppm) Example 11 Dye 10 (m=3, n=1) 6 parts diethylene glycol 30 parts N-methyl-2
-pyrrolidone 15 parts water
49 parts (mat copper I T7
c degree 3.6 ppm) Example 12 Dye 10 (m=2, n=2) 6 parts diethylene glycol 30 parts N-methyl-2
-pyrrolidone 15 parts water
49 parts (free copper ion concentration 4.7 ppm) Example 13 Dye 11 (m=3, n=2) 5 parts diethylene glycol 30 parts triethylene glycol monomethyl ether 10 parts water
55 parts (M# copper ion concentration 2.9 ppm) Example 14 Dyed Ne412 (m=3, n=1)
41 diethylene glycol
20 parts polyethylene L/7 glycol (Mwt, 2
00) 10? M water
66 parts (mal, copper: t
Concentration 4,0 ppm) Above theory 1! +1 As mentioned above, by using the wood-based ink 1, (1) the liquid has good long-term storage stability, especially thermal stability;
Less likely to cause clogging of the discharge port.

(2) Stable discharge of 70°C against fluctuations in temperature and driving conditions
- Once is wide.

(3) Fixation on the recording material is fast and the image is clear.

(4) The printed matter has good water resistance and light resistance.

(5) The ink is highly safe and does not attack surrounding materials (container sealing material, etc.).

There are advantages such as

Claims (3)

[Claims] (1) In a recording liquid containing a recording agent which is a component for forming a recorded image and a liquid medium for dissolving or dispersing this recording agent, at least one dye represented by the following general formula (A) is used as the recording agent. A recording liquid characterized by containing seeds. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(A) (However, Pc in the formula is the central atom of Cu, Fe,
Indicates a phthalocyanine skeleton coordinated with Co, Ni, Mg, Sn, Zn, or Mn, or a metal-free phthalocyanine skeleton that does not coordinate a metal atom, and M is selected from alkali metals, ammonium, and organic amines. Indicates any one base, m indicates a number of 2 to 3, n
represents a number from 1 to 2. ) A recording liquid characterized by containing a compound represented by: (2) The recording liquid according to claim (1), wherein the recording agent is a compound in which the central atom is Cu. (3) The amount of free copper ions included as impurities is 5pp
The recording liquid according to claim (2), wherein the recording liquid has a molecular weight of not more than m.