JPS61261377A - Recording fluid - Google Patents

Abstract

PURPOSE:To obtain a recording fluid which has excellent stability and does not cause clogging even after stored for a long period of time, by blending a recording agent contg. a water-soluble disazo compd. with a solvent for said recording agent. CONSTITUTION:In a recording fluid contg. a recording agent serving as a component for forming a printed image and a solvent for dissolving or dispersing said recording agent, a water-soluble disazo compd. of formula I is used as the recording agent. In the formula, A, B are each an (un)substituted benzene or naphthalene ring; C is (un)substituted naphthol; R<1>, R<2> are each OH, amino, morpholino, anilino which is substituted with SO3M (wherein M is alkali metal, ammonium, amino), etc. The amount of the dye to be used varies depending on the type of the solvent and the characteristics required of the recording fluid, and is generally 0.1-20wt%, pref. 1-10wt% based on the total amount of the recording fluid. Examples of the compds. of formula I are those of formulas II, III.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel recording liquid, particularly a recording liquid suitable for a recording method in which recording is performed by ejecting the liquid from fine ejection ports (ejection orifices) provided in a print head and flying the liquid as droplets. Regarding liquid.

BACKGROUND ART Writing instruments (fountain pens, felt-tip pens, etc.) for recording on recording materials such as paper have conventionally used inks prepared by dissolving various dyes in water or other organic solvents.

Furthermore, in the so-called inkjet recording method, in which recording is performed by ejecting liquid in the recording head from an ejection orifice using vibrations by a piezo vibrator or electrostatic attraction due to the application of high voltage, various dyes are dissolved in water or organic solvents. It is known that compositions are used. However, compared to ink for stationery such as general fountain pens and felt-tip pens,
Inkjet recording liquids are required to meet more stringent conditions in many properties.

In such an inkjet recording method, recording is performed by flying droplets of a recording liquid called ink and adhering them to a recording material. The basic components of such a recording liquid include a recording agent (dye or pigment is used) and a liquid medium for dissolving or dispersing it (water, various organic solvents, acids, or mixtures thereof are used), and as necessary. Various additives are added accordingly.

There are various types of such recording methods depending on the method of generating droplets and the method of controlling the flight direction of the droplets. An example of this is shown in FIG.

That is, the apparatus shown in FIG. 1 applies a recording signal to a recording head section having a piezo vibrator, and performs recording by generating droplets of recording liquid in response to the signal. In Figure 1, l
A recording head includes a piezo vibrator Ua, a diaphragm b, a recording liquid inlet 3, a liquid chamber in the head, and a discharge port (discharge orifice) S. A recording liquid 7 stored in a storage tank base is introduced into the liquid chamber through a supply pipe t. In some cases, an intermediate treatment means such as a pump or a filter may be provided in the middle of the supply pipe g. Then, a signal converted from the recording signal S into a pulse by a signal processing means (for example, a pulse converter) 10 is applied to the piezo vibrator core a, and a pressure change occurs in the recording liquid in the liquid chamber in accordance with the signal. . As a result, the recording liquid is discharged from the discharge orifice! The droplets ii are ejected from the droplets ii, and recording is performed on the surface of the recording material.

In addition, various types of devices other than the above-mentioned devices are known. For example, as shown in FIG. 1, as a modification of FIG. There is an apparatus in which a piezo vibrator is installed (the mechanism of droplet generation in this apparatus is essentially the same as the apparatus shown in FIG. 1). There is also a device that continuously generates charged droplets and uses a portion of the droplets for recording, or a device that applies thermal energy corresponding to the recording signal to the recording liquid in the chamber of the recording head, and uses the energy to generate the liquid. Devices that generate droplets are also known.

An example thereof is shown in Fig. 3-1, Fig. 3-b, and Fig. 3-3.

The head 13 is made of a glass, ceramic, or plastic plate having a groove/G for passing ink, and a heat-sensitive head tS used for recording (a thin film head is shown in the figure, but is not limited to this). ) and can be obtained by gluing them together. Fever head! are a protective film/A made of silicon oxide or the like, a heating resistor layer made of aluminum electrodes, a heat generating resistor layer made of nichrome, etc., a heat storage layer/9,
It is made of a substrate with good heat dissipation such as alumina.

The ink J/ has reached the discharge orifice, and the pressure P
A meniscus scope 3 is formed by this.

Now, when an electric signal is applied to the electrodes /7-/ and /7-, the area indicated by n of the heat generating head tS suddenly generates heat, bubbles are generated in the ink col in contact with this area, and the pressure causes Meniscus Scope J protrudes and ink U/ is ejected from orifice J! The recording droplet then becomes a recording droplet and flies toward the recording material S. Fig. D shows an external view of a multi-head in which a large number of heads shown in Fig. J-a are arranged. The multi-head is manufactured by bonding a glass plate core having multi-groove rollers and a heat-generating head 2g similar to that described in FIG. J-a.

Note that FIG. 3-a is a cross-sectional view of the head 13 along the ink flow path, and FIGS. 3-b and 7-b are cross-sectional views taken along line A-B in FIG. 3-a.

Conventionally, as this type of recording liquid, for example, Tokkosho! 0-13
No. 41, Tokuko Akira! ;/-110'1tl1, Tokuko Shoj
Products in which various dyes and pigments are dissolved or dispersed in aqueous or non-aqueous solvents as shown in Ko/3/Coro issue, JP S-13/Coa issue, and JP-A-30-9!001. It has been known. Preferred conditions for this type of recording liquid include (1) liquid physical properties (viscosity, surface tension, electrical conductivity, etc.) that match the ejection conditions (piezoelectric element drive voltage, drive frequency, orifice shape and material, orifice diameter, etc.); have.

(2) Stable for long-term storage and free from clogging.

(3) Fast fixation on the recording material (paper, film, etc.) and smooth dot periphery with little bleeding.

(4) The color tone of the printed image is clear and the density is high.

(5) The printed image has excellent water resistance and light resistance.

(6) The recording liquid should not corrode surrounding materials (containers, connecting tubes, sealing materials, etc.).

(7) It must be safe in terms of odor, toxicity, flammability, etc.

etc.

It is quite difficult to simultaneously satisfy the above characteristics. The prior art described above was unsatisfactory in this respect.

Since the recording liquid used for such recording purposes is basically composed of a dye and its solvent, the above-mentioned characteristics of the recording liquid are largely influenced by the inherent properties of the dye. Therefore, selecting a dye so that the recording liquid has the above characteristics is an extremely important technique in this technical field.

As a result of extensive research, the present invention was completed by finding a dye suitable for the recording liquid used for this purpose.

That is, the recording liquid of the present invention uses the following general formula [A] as an agent for forming a recorded image; , represents a naphthol which may have a substituent, R1 and V are a hydroxyl group,
It represents an amine group, a forporino group, an IJ) group substituted with an M group, an optionally substituted lower alkylamino group, and a piperazino group, and M represents an alkali metal, ammonium, or amines. ) is characterized in that it contains at least one dye represented by:

In the dye of general formula [A] contained in the recording liquid of the present invention, the substituents include So and M groups, and the substituents for B include hydroxyl group, 80. Examples include M group, amine group, mono-lower alkylamino group which may be substituted with 808M group, di-lower alkylamino group, acetylamino group, lower alkyl group, lower alkoxy group, chlorine atom and the like. Further, as substituents for C, hydroxyl group, 803M group, amino group, mono-lower alkylamino group, di-lower alkylamino group, 803M group,
．． Examples include anilino group, benzoylamino group, and acetylamino group which may be substituted with M group. Also, as M, N&, K, alkali metals such as Li, NH,, NH
(C,H40H),,N)l(CHs)s,NH(C
! Examples include ammonium and amines such as H5)S.

Specific examples of the dye represented by the general formula [A] contained in the recording liquid of the present invention include dyes having the following chemical structures.

A/ 03Nm λwax lsO’l nm Noriko λmax　400　nm Jf63 λwax　jdej　am & Hiroshi λwax! rtt nm A! λwax! rA! r nm flat 6 λwax! r deco nm Unreasonableness λwax 400! 11!1 &t λwax lsO! r　nm cliff 2 λmmx! gOnm Ya10 R λmax! II am A/co λmax AO da no JK/3 Spacing λ□x 40 pieces.

Mu/4I λml! ! De5nm ml! λmax! ;bjr nm mm 16 mm distance 2 mm, 610 mm! To 2m18576 □A/9 A-〇λwax 600 nm -l 4 λmax 1a00 am A here λwax 410 nm A here λmax! r90 nm Ya details O1Nm λmax 400 nm /fLkoj O1Nm λmax &0'l nm Yakoro 2mmw AIQ am A6 Body λwax lslyu nm Mucog H Yayut λmaw 60! nm λmax A/J nm These dyes can be found, for example, in "New Dye Chemistry" by Yutaka Hosoda (published on Core Day, December 1920), Gihodo, No. 3, Taku page Koku-
It can be obtained by the following method according to the description on page 391/line f etc.

After diazotizing amines represented by the following general formula []] [wherein, Hl, Bl are the same as defined above] using sodium nitrite, etc. in a mineral acid such as hydrochloric acid or sulfuric acid, the following general By coupling with amines represented by formula [1 [) % formula % ([1], monoazole represented by the following general formula [1 [wherein A, B, R', and R2 are the same as defined above]]) A compound is obtained.

The obtained monoazo compound is diazotized using sodium nitrite or the like in a mineral acid such as hydrochloric acid or sulfuric acid, and then converted to the following general formula [v] C...................................[v] [ In the formula, C is the same as defined above.] By coupling with a 7-tole group represented by the following formula, the water-soluble disazo compound of the present invention can be obtained.

Compared to recording liquids using conventionally known dyes having similar chemical structural formulas m to (5) below, these dyes have
Among the above-mentioned required characteristics, it is particularly stable for long-term storage and is extremely excellent in not causing clogging.
In addition, clear superiority is recognized in water resistance and light resistance.

O (Food black m;) In the inkjet recording method, nozzle clogging is a very important factor in terms of the reliability of the recording method. Mainly mechanical countermeasures have been taken, such as enveloping the water in a saturated steam state) and manual pumps, but these have not always been sufficiently effective.

Inkjet recording fluids mainly use water-based solvents for safety reasons, and generally a low-resolution water-soluble organic solvent such as glycols is added to this as a wetting agent. . The solubility of dyes in these liquid media varies slightly depending on their structure, and generally the solubility in water and the solubility in glycols even tend to contradict each other. At the tip of the nozzle, water, which is a highly volatile component in the ink, easily evaporates, and therefore the concentration of glycols tends to be high in this area.

Therefore, if a dye with low solubility in glycols is added to the recording liquid, there is a high risk that the dye will precipitate and cause nozzle clogging.

The dyes (11 to (5)) listed above show very good solubility in water but have poor solubility in glycols.On the other hand, the dyes used in the recording liquid of the present invention The dye represented by the general formula [A] has improved solubility in glycols while maintaining its solubility in water within a practically sufficient range, and therefore is extremely unlikely to cause nozzle clogging. It is something.

According to the present invention, the physical property values such as viscosity and surface tension are kept within appropriate ranges, the fine discharge orifice is not clogged, a recorded image of sufficiently high density is provided, and the physical property values are maintained during storage. A recording liquid that can record on a variety of materials without any change or precipitation of solids, has a high fixing speed, and provides images with excellent water resistance, abrasion resistance, and resolution. is obtained.

The content of the above-mentioned color component, that is, the dye, is determined depending on the type of liquid medium component, the characteristics required of the recording liquid, etc., but generally it is 0% by weight based on the total weight of the recording liquid.
．． 1-20%, preferably a,! The range is r-/j%, more preferably /-70%. Of course, these dyes can be used alone or in combination, or in combination with various dyes such as other direct dyes and acid dyes with the dye as an essential ingredient. Mixtures with various water-soluble organic solvents are used. Examples of water-soluble organic solvents include methyl alcohol, ethyl alcohol, n-7' lobil alcohol, isoflobil alcohol, n-butyl alcohol,
-carbon number/-& alkyl alcohols such as phthyl alcohol, t@rt-butyl alcohol, isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; tetrahydrofuran , ethers such as dioxane; nitrogen-containing heterocyclic ketones such as N-methyl-copyrrolidone and l,3-dimethyl-coimidazolidinone; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Pyrene glycol, butylene glycol, triethylene glycol, l, co, 6
- Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, such as hexandriol, thiodiglycol, hexylene f IJ col, diethylene glycol; glycerin; ethylene glycol methyl ether, diethylene glycol methyl (also ethyl) ether, triethylene Examples include lower alkyl ethers of polyhydric alcohols such as glycol monomethyl (or ethyl) ether.

The content of the above-mentioned water-soluble organic solvent in the recording liquid is generally 5 to 95% by weight based on the total weight of the recording liquid, preferably lθ~pro, and more preferably 10~! rO%
The range of

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

The recording liquid of the present invention prepared from such components has excellent recording properties (signal response, stability of droplet formation, ejection stability, long-term continuous recording, and long-term recording cessation). The composition has excellent, well-balanced properties such as ejection stability), storage stability, fixing property to recording materials, and light resistance, weather resistance, and water resistance of recorded images. In order to further improve such properties, various conventionally known additives may be further added.

Examples: Viscosity modifiers such as Eva, polyvinyl alcohol, cellulose, water-soluble resins; Various cationic, anionic or nonionic surfactants, surface tension modifiers such as jetanolamine and triethanolamine; PH modifiers using buffers , antifungal agents, etc.

In addition, in order to prepare the recording liquid used in the type of inkjet recording method that charges the recording liquid, lithium chloride,
A resistivity adjuster such as inorganic salts such as ammonium chloride and sodium chloride is added.

Note that when applied to an inkjet method in which recording liquid is ejected by the action of thermal energy, thermal properties (e.g., specific heat, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted. .

The invention will be explained in more detail in the following examples.

Example 1 Ion-exchanged water (hereinafter abbreviated as water) 1 part by weight of diethylene glycol dye The recording liquid was degassed. Using the obtained recording liquid, the following (T , ) to (T, ) were investigated, and good results were obtained for all of them.

(〒1) Long-term storage stability of the recording liquid: Even after storing the recording liquid in a sealed glass container at -5OC and 60℃ for 6 months, no precipitation of insoluble matter was observed, and there was no change in the physical properties or color tone of the liquid. There was no.

(T) Ejection stability: Continuous ejection was carried out for several hours in an atmosphere of room temperature and 5C141°C, and stable high-quality recording was possible from beginning to end under all conditions.

(T,) Ejection response: Intermittent ejection for seconds and ejection after standing for months were investigated, and in both cases stable and uniform recording was achieved without clogging at the orifice tip.

(T4) Quality of recorded images: The recorded images had high density and were clear. Indoor light? The rate of decrease in density after being exposed for a month was less than t%, and when immersed in water for 1 minute, there was very little blurring of the image.

(T,) Fixability on various recording materials: After printing with the recording materials listed in the table below, after is seconds, the printing area was rubbed with a finger to determine the presence or absence of image shift/bleeding, and there was no image shift/bleeding. It showed excellent fixing properties.

The dye A/ used in this example was synthesized as follows.

(1) Production of the first diazo liquid 3% of the triazine compound 4'0.79- of the above structural formula
The mixture was added to 5lI6- of hydrochloric acid and stirred for 3 hours to form a homogeneous slurry. Add ice o o two to this and J″CGCCG
C. In the cooling slurry, add 7.3 ml of sodium nitrite to 73 ml of water.
An aqueous solution in which y- was dissolved was added. Then, after diazotization by stirring at 3°C for 1 hour, sulfamic acid 3? was added to eliminate the remaining sodium nitrite to obtain a first diazo solution.

(2) Manufacture of the first cociazo liquid/Cucrep acid coco, J? was added to water and stirred for an hour to form a homogeneous slurry. To this was added 300 f of ice, the first diazo solution obtained in (1) above, and 10% of 25% sodium hydroxide, and the temperature was 0~JC and the pH was ~3. After coupling was performed by stirring for f hours, salting out was performed by adding common salt. After filtering the precipitated monoazo compound, it was washed with 5OO- of salt solution and dried to obtain the following monoazo compound 03Nm! rt, OfP was obtained. Obtained monoazo compound, 1
2. /ft-! % hydrochloric acid qto- and stirred for S hours to make a homogeneous slurry, then added to ice 300%? was added and cooled to JCK. An aqueous solution in which water 31:tdllC sodium nitrite J, l:f was dissolved was added to this slurry. then 3
After diazotization by stirring at ℃ for several hours, sulfamic acid l? was added to eliminate the remaining sodium nitrite to obtain a first cociazo solution.

(3) Coupling λ-amino-g-hydroxynaphthalene-3,6-disulfonic acid tt,,op to water qbo111! After adding to
To this, ice t00f, the first cociazo liquid obtained in (2) above, and 25% strength soda! ! - was added and coupling was carried out at pHt~1O1 temperature ~SC. Same temperature, same PK
After stirring for 3 hours, add 2! Of was added to perform salting out. After filtering the precipitated compound, it was washed with 10176 saline solution 300% and washed with Wet Cake Co., Ltd. I got it.

This wet cake was desalted and then dried to obtain the target compounds J i, i g-. The yield was 60%.

The results of elemental analysis were as follows.

Example 1 A recording liquid having the above composition was prepared in the same manner as in Example 1, and an on-demand type multi-head (on-demand type multi-head) that performs recording by applying thermal energy to the recording liquid in the recording head to generate droplets.
Discharge orifice diameter Jjμ, heating resistor resistance value lsOΩ,
Similar to Example 1, VC(Tl') to (T,) were investigated using a recording device having a driving voltage JOV and a frequency KHz), and excellent results were obtained in all the investigation experiments. .

The dye of Ni-3 used in this example was synthesized as follows.

(1) Production of first diazo liquid A first diazo liquid was obtained in accordance with the method (1) of Example 1, except for the following steps.

(2) Production of the first diazo liquid, using co,S-dimethoxyaniline in place of l,7-crepe acid, and the first diazo liquid obtained in the above (1) and (2) of Example 1. Coupling was carried out according to the method described in 1. The following diazo solution of a monoazo compound (Part 1) was obtained.

(31 Coupling 1-Hydroxy-Cu-3'-Sulfo)anilino-naphthalene-3,/1-disulfonic acid 1-de, t? The desired dye J Lj f was obtained according to the method (3) of Example 1 using The yield is 6g! It was excellent.

The results of elemental analysis were as follows.

Example J A recording liquid having the above composition was prepared in the same manner as in Example 1, and an on-demand type multi-head (on-demand type multi-head (
Discharge orifice diameter 35μ, heating resistor resistance troΩ,
(T,) to (T,) were investigated in the same manner as in Example 1 using a recording device with a driving voltage of 77 V and a frequency of -KHz, but excellent results were obtained in all of the investigation experiments. Ta.

Example 1 A recording liquid having the above composition was prepared in the same manner as in Example 1, and an on-demand type multi-head (on-demand type multi-head) was prepared in which thermal energy was applied to the recording liquid in the recording head to generate droplets and perform recording.
Discharge orifice diameter 35μ, heating resistor resistance value lj0Ω,
(T1) to (T,) were investigated in the same manner as in Example 1 using a recording device having a driving voltage of 30 V and a frequency of -KHz, and excellent results were obtained in all of the investigation experiments.

Example A recording liquid having the above composition was prepared in the same manner as in Example 1, and an on-demand type multi-head (on-demand type multi-head) that performs recording by applying thermal energy to the recording liquid in the recording head to generate droplets.
Discharge orifice diameter 35μ, heating resistor resistance value ljOΩ,
Similar to Example 1, studies on (T, ) to (Ill, ) were conducted using a recording device with a driving voltage of 30 V and a frequency of kHz (KHz), and excellent results were obtained in all of the study experiments. .

Examples 6 to 13 Recording liquids having the compositions shown below in 6 to 13 were prepared in the same manner as in Example 1. These compositions were filled into felt-tip pens and written on medium-quality paper (Hakubotan: Honshu Paper Industries) to examine water resistance and writability after removing the cap and leaving the pen for a long time.

The recording liquid of this example was excellent in both water resistance and writability after standing.

In addition, in Example 6, A//I was used instead of the dye compound unevenness.
/ko, ts, ilI, ts, ib.

17,/za,/? , and in Examples, instead of the dye compound MuJ, 厘ゆL, KOKO, KO3゜KODA, KOS were used,
Furthermore, in Example DA, instead of the dye compound Muro, Tomokoro,
Example 1: Prepare recording liquid using core, core 31
Similar studies were conducted on K(T1) to (T,), and good results were obtained in all of the study experiments.

[Brief explanation of drawings]

FIGS. 1 and 1 are schematic diagrams of an inkjet recording apparatus, respectively. Figures J-a, 7-b are a vertical sectional view and a horizontal sectional view of a main part of another recording device. FIG. 7 is an external perspective view of a multi-head head shown in FIGS. J-a and 3-b. However, in the diagram! ... Recording head, core a... Piezo vibrator, core b.
...Vibration plate, 3...Inlet, lI...Liquid chamber,!・・・
・Discharge orifice, 6. ...Storage tank, 7.Recording liquid, t.. Supply pipe, ri..Intermediate processing means, io.
...signal processing means, //...droplet, /2. ．． 2. ! t
...recording material, S...recording signal, /41...liquid chamber, tS...heat generating head. 14... Protective layer, /7... Electrode, /1... Heat generating resistor layer, IT... Heat storage layer, -〇... Substrate, -6...
・It is a groove.

Claims (2)

[Claims] (1) In a recording liquid containing a recording agent, which is a component for forming a recorded image, and a solvent for dissolving or dispersing this recording agent, the recording agent has the following general formula [A] ▲ Numerical formula, chemical formula, There are tables, etc. ▼ [A] (In the formula, A and B represent a benzene ring or a naphthalene ring that may have a substituent, C represents a naphthol that may have a substituent, and R^ 1 and R^2 represent a hydroxyl group, an amino group, a morpholino group, an anilino group substituted with a SO_3M group, an optionally substituted lower alkylamino group or a piperazino group, and M represents an alkali metal, ammonium or amines. .) A recording liquid characterized by containing at least one dye represented by: (2) The recording liquid according to claim 1, wherein the dye represented by the general formula [A] is contained in an amount of 0.1 to 20% by weight based on the total weight of the recording liquid.