JPS58173171A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a recording liq. with great reliability, giving a recording head prolonged service life and reduced failure rate, by incorporating a particular bisazo compd. as a recording agent forming recorded image. CONSTITUTION:As a recording agent forming recorded image, a recording liq. contg. a dye of formula I (wherein Q1, Q2 are each a phenyl or naphthyl group optionally substituted with -CH3, -C2H5, -OH, -Cl, -Br2, -NH2, -NO2, -SO3M, or a group of formula II; R1 is H, OH; R2 is H, NH2, OH; R3 is H, COOM'', SO3M'''; R4 is H, NH2, OH; M', M'' and M''' are each Na, K, Li, ammoniums, amines) is yielded. Dyes of formula I include those of formulas III, IV, etc. Said recording liq. can be given as a liq. compsn. that is called ink by blending solvents such as water or org. solvents and, if necessary, additives such as a surface tension modifier or viscosity modifier with dyes as recording agents.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is suitable for use with current recording liquids, particularly inkjet recording methods in which droplets are ejected from fine ejection ports (ejection orifices) provided in a print head. Regarding recording 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.

In the sub-inkjet recording method, in which recording is performed by ejecting the liquid in the recording head using vibration from a piezo vibrator or electrostatic attraction due to the application of high voltage, various dyes are mixed with water or organic solvents, etc. It is known to use compositions dissolved in However, compared to ink for literary collections such as general fountain pens and felt pens, inkjet recording liquids require strict conditions in terms of many characteristics.

The inkjet recording method does not generate noise and can perform high-speed recording or color recording on plain paper without special fixing treatment, and various types of inkjet recording methods are being actively researched.

In such an inkjet recording method, recording is performed by ejecting droplets of a recording liquid called ink and adhering them to a recording material. The basic components of such a recording liquid are 1) a recording agent (dye or pigment is used) and a liquid medium for dissolving or dissolving it (7) a liquid medium (water or various organic solvents or a mixture thereof may be used). Various additives are added as necessary.

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

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 FIG. 1, reference numeral 1 denotes a recording head, which is located in a liquid chamber 4 having a piezo vibrator 2a, a diaphragm 2b, a recording liquid inlet 3, a 1H14 in the head, and a discharge port (discharge orifice) 5. A recording liquid 7 stored in a storage tank 6 is introduced through a supply pipe 8. Incidentally, an intermediate treatment means 9 such as a pump or a filter may be provided in the middle of the supply pipe 8 depending on the case. A signal converted from the recording signal S to a Norlus by a signal processing means (for example) (Luss converter) 10 is applied to the piezo vibrator 2&, and the liquid chamber 4
Pressure changes occur in the recording liquid inside. As a result, the recording liquid 7 is discharged from the discharge orifice 5 in the form of droplets 11, and recording is performed on the surface of the recording material 12.

Various types of devices are known in addition to the device described in E. For example, as shown in FIG. 2, as a modification of FIG. There is a device in which a piezoelectric vibrator is installed (the mechanism of droplet generation in this device is essentially the same as the device shown in FIG. 1). Also, a device that continuously generates charged droplets and uses a part of the droplets for recording, or a device that applies 1° good thermal energy to the recording liquid in the chamber of the recording head corresponding to the recording signal,
Devices that generate droplets using this energy are also known.

An example thereof is shown in Fig. 3-&, Fig. 3-b, and Fig. 4.

The head 13 is made of glass, ceramics, plastic plate, etc. having #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). Obtained by gluing. The heat-generating head 15 includes a retentive film 16 made of silicon oxide or the like, aluminum electrodes 17-1, 17-2, a heat-generating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a material with good heat dissipation properties such as alumina. It consists of a substrate 20.

The ink 21 comes from the discharge orifice 221 and the pressure P
A meniscus 23 is formed by 0 Now, an electric signal is applied to electric 1i1771.17-2
The part indicated by n of the heat generating head 15 suddenly generates heat, and bubbles are generated in the ink 21 in contact with this part, and the meniscus 23 is protruded by the pressure, and the ink 21 is ejected from the orifice 22 to form a recording medium 24. It flies toward the recording material 25. FIG. 4 shows an external view of a companion multi-head in which a large number of heads shown in FIG. 3-a are arranged. The multi-head is made by bonding a glass plate 27 having multi-grooves 26 and a heat-generating pad 28 similar to that described in FIG. 3-a.

In particular, in the liquid jet recording method that uses thermal energy, if you want to record high-resolution, high-quality images at higher speed for a longer period of time, or if you want to dramatically improve the service life of the device, It is necessary to improve the repeated use life (durable life) of recording hutchers.

Factors that determine the service life of a recording head applied to the above-described recording method include the life of the heat-generating head provided therein, as well as the deposition of hard particles on its surface.

During this repeated generation and disappearance of bubbles, the recording liquid is exposed to temperature, so it is expected that the thermally unstable recording liquid will undergo chemical changes.

In fact, if the generation and disappearance of bubbles continues for a long time, as a result, insoluble matter will be formed and dissipated near the surface of the heating head.
Deposition may cause the head to become unable to eject.
It has been experienced and observed in many experiments.

The present invention has been made specifically to eliminate the above-mentioned disadvantages, and can significantly extend the service life of the recording head applied to the recording method described in the above-mentioned publication. The purpose of this invention is to provide a recording liquid that can significantly reduce the failure rate of the head and improve its reliability.

The recording liquid of the present invention which achieves the above object contains a compound (dye) represented by the following general formula as a recording agent.

R1 (However, in the above formula, sQ and pQz represent an unsubstituted or substituted phenyl group or a substituted naphthyl group) L, sonotoquino substituent is -CH3, -C,T(,, -() H.

-CJ, -Br, -NHx, -Nov,
-805M, -N<3 items, 8o8M.

At least one selected from the following. Father, R1 is H
or OH, R1 is either H, NH2, or OH, R1
is either H, C00M", solM"'o, R4
represents either H9NH, OH. In addition, the above M, M
'.

M "2M" is Nq, Li, ammonium, respectively.

It is selected from among amines. ) In particular, the recording agent of the present invention described above has a decomposition product that has sufficient solubility in a liquid medium even when the azo bond (-N-N-) is cleaved when heated to 250° C. or higher. It is something. Therefore, even when bubbles are repeatedly generated and extinguished over a required period of time, no insoluble matter is generated or deposited on the surface of the heat-generating head, and the recording head does not become incapable of ejecting.

Father, use it as a recording agent of the present invention! 1. As predicted from its molecular structure, dyes have sufficiently satisfactory IIIs properties with respect to liquid media, and in particular have excellent solubility in water, so they are useful when forming aqueous recording liquids. 4 can always be used effectively.

Further, the recording liquid of the present invention contains water, water, and dye in addition to the recording agent.
By adding and blending a suitable solvent such as an organic solvent and, if necessary, additives such as a surface tension modifier and a viscosity modifier, a liquid composition called a so-called ink can be obtained.

Using this recording liquid, as shown in FIG. If recording is performed with a recording head, the service life of the recording head can be dramatically improved compared to the case where a conventional recording liquid is used, as shown in the following examples.

Specific examples of the recording agent used in the present invention include dyes having the following chemical structures.

Eyebrow l H2N N1 (2 0, N Of (Mu 4 Le N NH2 Demon 7 COONa Eyebrow 13 0) I0O
Na 03Na 20 21 24 S O, Na Jl; 25 to aυ3b 2N 4ct OtN S 0sNa
The sulfone groups or carboxyl groups in the compounds of Jokifu 1 and 32 are all expressed in the form of sodium (Na) salts, but in addition, nonorium (K), lithium (Li) , ammonium printing, or salts with amines.

Note that water or a mixture of water and a water-soluble organic solvent is used as the liquid medium component for forming the recording liquid of the present invention. Examples of water-soluble organic solvents include methyl alcohol.

Ethyl alcohol, n-7' lobil alcohol, ingropil e alcohol, rl-7' nal-furcol, formula-7' f alcohol, tert-butyl alcohol, isofthyl alcohol, etc. Alkyl/alcohol mounds; Amides such as dimethylformamide and dimethylacetamide; Ketones such as acetone and diacetone alcohol; and ethers such as phtrahydrofuran and dioxane; N-methyl-2-pyrrolidone, 1.3 dimeth A-2-Nitrogen-containing heterocyclic chthons such as imidazolidinone; polyalkynone glycols such as polyethylene glycol and polypropylene glycol; -ethylene glycol, globylene glycol, phthylene glycol, triethylene glycol, 1,2, Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms such as 6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin; ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl Examples include lower alkyl ethers of polyhydric alcohols such as (or ethyl) ether.

Among these many water-soluble organic solvents, diethylene glycol, which is a polyhydric alcohol, and triethylene glycol monomethyl (or ethyl) ether, which is a lower alkyl ether of a polyhydric alcohol, are preferred.

The content of the water-soluble organic solvent in the recording liquid is generally in the range of 5 to 95% by weight, preferably 10 to 80%, and more preferably 20 to 50% based on the total weight of the recording liquid. Ru.

The recording liquid of the present invention prepared from such components has excellent recording properties (signal response, droplet formation stability, ejection stability > i ″1/+.

Continuous recording of printing time, g1 output stability after long-term recording suspension) Storage stability, recording medium dissolution stability.

Fixability to the recording material or one-light property of the recorded image.

Weather resistance, water resistance, alcohol resistance, etc. are all well-balanced and excellent. In order to improve these properties, various conventionally known additives may be further added.For example, viscosity modifiers such as polyvinyl alcohol, cellulose, and water-soluble resins; Surface tension regulators such as cationic, anionic or nonionic surfactants, jetanolamine, triethanolamine; PHv by buffering agents
4. The following can be mentioned.

In order to prepare the recording liquid used in the type of recording method that charges the recording liquid, lithium chloride, ammonium chloride,
Resistivity modifiers such as inorganic salts such as sodium chloride are used. Urea and thiourea are preferably used as water retention improvers at the tip of the discharge orifice.In addition, in the case of a type that discharges the recording liquid by the action of thermal energy,
Thermal physical property values (eg, specific heat, coefficient of thermal expansion, thermal conductivity, etc.) may be adjusted.

When the recording liquid of the present invention is used as a so-called recording liquid for writing instruments, it is necessary to adjust its physical properties in consideration of viscosity, compatibility with various materials to be recorded, etc.

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

Example 1 KSiO on alumina substrate! The layer (lower layer) is formed to a thickness of 1 μm by sputtering, followed by Hf as a heating resistance layer.
B, with 100G thickness and 1 aluminum electrode, 30
After laminating to a thickness of 00A, a thickness of 50μ is achieved by selective etching.
A heating resistor pattern of B x 200 μm was formed.

Next, 5 tot layers were laminated as an insulation layer (upper layer) to a thickness of 3500A by tuttering to form an electrical/thermal converter on the substrate.After that, a glass plate with grooves of 50 μm width x 50 μm depth was carved. were joined so that the groove and the heating resistor matched.Subsequently, the end face of the orifice was polished so that the distance between the tip of the heating resistor and the orifice was 250 μmK to create a recording head.9 Using this recording head, Ink having the liquid composition shown below was ejected.

In this case, when the recording head was driven with a rectangular voltage pulse print signal of 10μ36C and 40V at a cycle of 200μ, it had a lifespan sufficient to withstand 160 hours of continuous printing.

Example 2 Durability time of the recording head when various dyes of the structural formula KM shown in the table below are used as substitutes for the dye of structural formula 19 in the ink having the liquid composition used in Example IK. are shown in Table 1 and circled.

The head was driven using a lOμ type, and a 50V rectangular voltage pulse print signal was used at a cycle of 200μ.

(Table 1) Example 3 The same results as in Example 1 were obtained when triethanolamine was used instead of N-methyl-2-pyrrolidone in the ink composition used in Example I.

Example 4 When ethylene glycol was used in place of diethylene glycol in each ink composition used in Example 2, the same results as in Example 2 were obtained.

Example I15 Dye/Numerum 3,415°J1 used in Example 2
19,. 413, 416, 424, 427, and 432, ink is prepared by forming salts with K, Li, ammoniums, and amines in place of Na for the sulfonic groups, and using friendly dyes. The durability time of the recording head was investigated in the same manner as in Example 1 using each of the inks, and the same results as in the case of the sodium salt (see Example 2) were obtained.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic diagrams of an inkjet recording apparatus, respectively. Figures 3-a and 3-b are a vertical sectional view and a horizontal sectional view of a main part of another recording device. FIG. 4 is an external perspective view of a multi-head head shown in FIGS. 3-a and 3-b. However, in the figure, l...recording head, 2&... piezo vibrator, 2b...
...Vibration plate, 3...Inflow port, 4...Liquid chamber, 5...
Discharge orifice, 6... Storage tank, 7... Recording liquid, 8... Supply pipe, 9... Intermediate processing means, 10...
Signal processing means. 11-...Droplet, 12.25...Recording material, S...Recording signal, 14...Liquid chamber, 15...Heating head, 16
...protective layer, 17...electrode, 18...heating resistor layer, 19...heat storage layer, 20...substrate, 26...groove. Patent applicant Canon Co., Ltd. F'. j'A

Claims (1)

[Scope of Claims] A recording liquid characterized by containing a compound represented by the following general formula as a recording agent for forming a recorded image. R1 3 ((However, in the above formula, sQt*Q* represents an unsubstituted or substituted phenyl group, or a substituted phenyl group,
The substituent at that time is -CI5-Cb. -OR, -CI, -Br, -NH,, -No,
, -8o, M. '<(C)It)tSO&M'. Also, R1 is H or OH, R7 is either H or Nlm2゜OH, and R8 is H, C00M"
, So, M"/ノ=&IJrekawo, R4 is H, NH
, , OH. In addition, the above M, M', M "2M" are respectively Na, K,
Li. It is found among ammoniums and amines. )