JPS62250067A - Water-soluble dye and production thereof - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [A and B are (substituted)benzene ring or (substituted)naphthalene ring; m is 0 or 1; M is alkali metal, ammonium or amine] containing 0.0001-3wt% sulfate radical as an impurity. EXAMPLE:The compound of formula II. USE:Dye for recording liquid of ink-jet recording apparatus or writing utensil such as fountain pen, felt pen, etc. Ink containing said dye has excellent storage stability and dissolution stability, gives recorded image having excellent water- resistance and light-fastness and does not cause clogging of nozzle, orifice, etc. PREPARATION:The amine of formula A-NH2 is diazotized in a mineral acid and coupled with the amine of formula H-B-NH2 to obtain a monoazo compound of formula A-N=N-B-NH2. The product is diazotized in a mineral acid and coupled with a naphthol compound of formula III to obtain the disazo compound of formula IV, which is diazotized in the same manner and coupled with m- phenylenediaminesulfonic acid.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a water-soluble dye suitable for use in a recording liquid (hereinafter referred to as ink) used in an inkjet recording device or a writing instrument such as a fountain pen or a felt-tip pen, and its production. Regarding the law.

[Conventional technology]

Inkjet recording methods include various ink ejection methods (for example, an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, a method that heats the ink and uses the pressure generated at that time, etc.). In this method, ink droplets are formed using a recording medium, and some or all of these droplets are attached to a recording material such as paper to perform recording. Furthermore, when using a writing instrument such as a fountain pen, felt-tip pen, or ballpoint pen, as is well known, ink is ejected from the capillary pores and is received by a recording material to perform recording.

Ink used in such inkjet devices or writing instruments is known to be one in which various water-soluble dyes or pigments are dissolved or dispersed in water or a liquid medium consisting of water and a water-soluble organic solvent. ing.

(Problem to be solved by the invention) It is natural that various performances are required of conventional inks such as those mentioned above, but the most required performance is that of recording using ink. The stability of the liquid means that there will be no clogging or sedimentation in the nozzle, orifice or pen tip of the recording device when recording is interrupted or when recording is not performed for a long period of time.

Direct dyes, acid dyes and basic dyes are usually preferably used as water-soluble dyes.

However, since these dyes were originally produced for dyeing fibers, they are not necessarily suitable as dyes for use in brocade liquid.

Furthermore, these dyes usually contain large amounts of inorganic salts such as sodium sulfate, and when recording inks are prepared using dyes containing large amounts of sodium sulfate, the following undesirable effects occur: bring about a situation.

That is, when a large amount of sodium sulfate is contained in the ink, the stability of dye dissolution in the ink is reduced, leading to aggregation and precipitation of the dye. Furthermore, in inkjet recording, when the ink evaporates at the ejection orifice and the liquid composition changes, sodium sulfate, which has low solubility in glycol, etc., is precipitated.

All of these cause clogging of the ejection orifice, which is the most important thing to avoid in inkjet recording. If the ink is prone to clogging, the dye density must be lowered, resulting in a recorded image with insufficient density, poor quality, and poor light resistance.

Conversely, if the sulfate groups in the ink are extremely reduced, the solubility of the dye itself in water will be impaired.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to be suitably used as a recording agent for inks used in various recording methods, to have excellent storage stability and dissolution stability, and to provide water resistance of recorded images. An object of the present invention is to provide a water-soluble dye having excellent light resistance and other recording properties, and a method for producing the same.

Another object of the present invention is to prepare an ink that has excellent dissolution stability during use and long-term storage, and does not cause clogging of nozzles, orifices, etc., despite high dye concentration. An object of the present invention is to provide a water-soluble dye and a method for producing the same.

(Means for solving problems) The above object is achieved by the present invention as follows.

That is, the present invention is a water-soluble dye having a structure represented by the following general formula (1) and containing 0.0001 to 3% by weight of sulfate radicals as impurities.

(However, in the above formula, A and B are unsubstituted or substituted benzene rings,
(represents a naphthalene ring, m represents O or l, M represents an alkali metal, ammonium or amines) Furthermore, the present invention provides a process for synthesizing a water-soluble dye represented by the following general formula (I), and the dye This is a method for producing a patented dye, which comprises the step of adjusting the concentration of sulfate radicals contained in the dye to 0.0001 to 3% by weight.

(However, in the above formula, A and B are unsubstituted or substituted benzene rings,
(represents a naphthalene ring, m represents O or 1, and M represents an alkali metal, ammonium or amines) [Function] As a result of extensive study, the present inventor discovered that the dye represented by the general formula (I) It has been discovered that the dye has excellent performance as a dye used in inks, especially light resistance, water resistance, solubility, and color tone, and furthermore, the concentration of sulfate radical (SO4) contained in this dye is 0.0001% by weight. By adjusting the dye concentration to ~3% by weight, preferably 0.0001% to 1.2% by weight, nozzles, orifices, etc. will not be clogged during use or long-term storage, despite the high dye concentration. They completed the present invention by discovering that it is possible to prepare ink with excellent stability.

Specific examples of the dye represented by the general formula (I) of the present invention are listed below.

No, I No, 2 No, 3 03K No, 4 No, 5 The above-mentioned dyes are described, for example, in Yutaka Hosoda's "New Dye Chemistry" (Showa 4).
(Published on December 21, 1998) Gihodo, page 397, lines 27-3
It can be obtained by the following method according to the description on page 98, line 19, etc.

Using amines represented by the following general formula (n) A-NH2... [■] [In the formula, A is the same as the above definition] and sodium nitrite in a mineral acid such as hydrochloric acid or sulfuric acid, After diazotization, coupling with an amine represented by the following general formula [I [[] % formula % [in the formula, B is the same as the above definition]] gives the following general formula [IV] A-N=N- B-NH2...(IV) [A in the formula
, B is the same as defined above] A monoazo compound represented by the following is obtained.

After diazotizing the obtained monoazo compound in a mineral acid such as hydrochloric acid or sulfuric acid using sodium nitrite or the like, a naphthol represented by the following general formula (V) [wherein m and M are the same as defined above] By coupling with, the following formula [■] 0H [In the formula, A, B, M, and m are the same as the above definition]
A disazo compound represented by is obtained.

This disazo compound is diazotized in a mineral acid such as hydrochloric acid or sulfuric acid or in an organic acid such as acetic acid using sodium nitrite, etc., and then coupled with metaphenylenediamine sulfonic acid to form a water-soluble trisazo compound of the present invention. A compound is obtained.

Compared to conventionally known dyes having similar chemical structural formulas (1) to (5) below, these dyes are particularly stable for long-term storage among the required characteristics for recording liquids containing them. In addition to being extremely superior in not causing clogging, the discharge response is also good, and a clear superiority is recognized.

(Food Black-2) (Direct Black-38) (Direct Blue-8) SO3Na =-(4)(
Direct Black-9) (Direct Green-33) Furthermore, in the present invention, methods for controlling the concentration of sulfate groups in the dye include salting out, dialysis, recrystallization by solvent treatment, ion exchange, ultrafiltration, reverse Commonly known methods such as infiltration, acid precipitation, chemical treatment, electrodialysis, etc. can be used. The water-soluble organic solvent used in the recrystallization method by solvent treatment may be any water-soluble organic solvent as long as it is a poor solvent for sodium sulfate and a good solvent for the dye, and the selection of the solvent should take into account the structure of the dye to be treated. You can arbitrarily choose the most suitable one. Usually, alcohols, glycols, and glycol ethers can be preferably used. Among these, industrially preferable methods include ultrafiltration and reverse osmosis.

The water-soluble dye produced in this way is generally used in a proportion of about 0.1 to 20% by weight in conventional inks, but in the present invention, based on the knowledge of the inventor, Based on this, not only can it be used within the above range, but even when used in an amount greater than the conventional amount, it exhibits liquid stability greater than that of conventional ink compositions and does not produce precipitates.

The solvent used to prepare ink using the water-soluble dye 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. As a water-soluble organic solvent, it has the effect of preventing ink from drying. Furthermore, 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. Carbon number 1~
4-alkyl alcohols; amides such as dimethylforamide and dimethylacetamide; ketone or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexandriol, diodiglycol, hexylene glycol, diethylene glycol, etc. ; Glycerin; Lower alkyl ethers of polyhydric alcohols such as ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, l, Examples include 3-dimethyl-2-imidazolidinone.

Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferred.

The content of the water-soluble organic solvent in the ink is generally 0 to 95% by weight, preferably 10 to 80% by weight, more preferably 20 to 50% by weight based on the total weight of the ink. range.

The water content at this time is determined within a wide range depending on the type of solvent component, its composition, or the desired properties of the ink, but is generally 10% of the total weight of the ink.
The content is in the range of ~100% by weight, preferably 10-70% by weight, more preferably 20-70% by weight.

The basic components of the ink composition using the water-soluble dye produced according to the present invention are as described above.

The water-soluble dye of the present invention obtained as described above has sufficiently solved the problems of the prior art, and by adjusting the ink using this dye, the stability of recorded images (light fastness, water resistance) can be improved. In addition to achieving long-term storage stability, especially recording characteristics (signal response, droplet formation stability, ejection stability) in inkjet recording methods, long-term continuous recording It is well-balanced in terms of performance, stability of ink ejection after a long period of suspension of operation, etc., and can be effectively used as an ink for various types of inkjet recording or as an ink for writing.

Next, the present invention will be explained in more detail with reference to Examples. still,
In the text, parts or percentages are based on weight.

The synthesis and preparation of the dye of Specification Example No. 1 is shown.

Example 1 The compound (A) is stirred in dilute hydrochloric acid to form a uniform slurry. Add the drained water and cool. A sodium nitrite aqueous solution is added to this slurry, and then stirred at 3° C. for 3 hours to effect diazotization. Thereafter, sulfamic acid is added to this to eliminate the remaining sodium nitrite to obtain a diazo solution.

Next, the compound (B) was dissolved in water to form a uniform slurry. Add hydric soda, ice and the above diazo solution to this and 3°C.
After coupling was performed at pH 2 to 3, salt was added to perform salting out. After filtering the precipitate, it is dried (C
) was obtained.

The obtained monoazo compound was stirred in dilute hydrochloric acid to form a uniform slurry, and then ice was added to cool it. A sodium nitrite aqueous solution was added to this slurry, stirred at 3°C for 3 hours,
After diazotization, sulfamic acid was added to eliminate remaining sodium nitrite to obtain a diazo solution.

Next, the compound (D) was dissolved in water, ice, the above-mentioned diazo liquid, and hydric soda were added thereto, and the mixture was heated under weak alkalinity at a temperature of 2 to 5 ml.
Coupling was performed at °C.

Under the same conditions, after thorough stirring, salt was added to perform salting out. The precipitate was collected by filtration and dried to obtain a disazo compound represented by (E).

Next, the compound (E) is stirred in dilute hydrochloric acid to form a uniform slurry. The condensate water was added and cooled. A sodium nitrite aqueous solution was added to this slurry, and the slurry was then stirred at 3° C. for 3 hours to effect diazotization. Thereafter, sulfamic acid is added to this to eliminate the remaining sodium nitrite to obtain a diazo solution.

On the other hand, compound (F) was dissolved in water, and ice, the above-mentioned diazo solution, and suppurated soda were added thereto, and coupling was performed at a pH of 2 to 3 and a temperature of 2 to 5°C. After sufficient stirring under the same conditions, salting out was performed by adding common salt. The precipitate was collected by filtration and dried to obtain dye 1.

This dye (10 parts by weight) and ion exchange water (90 parts by weight)
After sufficiently mixing and dissolving in a container, purification is performed by using a polyolefin ultrafiltration membrane (NTU-2006: manufactured by Nitto Denko Corporation) and replenishing ion-exchanged water in the amount of the filtrate to be discharged. . Then, purification was continued until the concentration of sulfate radicals contained in this dye became 3% by weight based on the pure content of the dye.

Next, concentrate to dryness using an evaporator, and form the powdered dye (1).
get.

Usage example 1 Using this dye, an ink having the following composition was prepared.

Triethylene glycol 20% N-methyl-
2-Pyrrolidone 15% Dye (■) 5% Ion-exchanged water 60% This ink is used to generate droplets by applying thermal energy to the ink in the recording head. Orifice diameter 35 microns, heating resistor 150 ohms, drive voltage 30 volts, frequency 2 KHz
), the following examinations were conducted on T1 to T5, and good results were obtained in all cases.

(T1) Long-term storage stability: Even after sealing the ink in a plastic film bag and storing it at -30°C and 60°C 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.

(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) Discharge responsiveness: Investigated discharging for 2 seconds and discharging after standing for 2 months. In both cases, there was no clogging at the tip of the orifice, and stable and uniform discharging was achieved.

(T4) Quality of recorded images: The images recorded on the recording materials listed in Table 1 below had high density and were clear. After six months of exposure to indoor light, the rate of decrease in concentration was less than 1%.

(T5) Fixability on various recording materials: After 15 seconds of printing on the recording materials listed in Table 1 below, rub the printed area with your finger and the image may shift.
When the presence or absence of bleeding was determined, all showed excellent fixing properties with no image shift or bleeding.

Example 2 Dye 2 exemplified in the specification was synthesized in the same manner as in Example 1.

After sufficiently mixing and dissolving this dye 2 (10 parts by weight) and ion exchange water (90 parts by weight) in a container, reverse osmosis membrane (NTR)
-1130: Nitto Denko Co., Ltd.), and purification is performed by replenishing ion-exchanged water by the amount of the filtrate to be discharged. Next, it is concentrated to dryness using an evaporator to obtain a powdered dye (n).

When the concentration of sulfate radicals contained in this dye was measured using an ion chromatography device, the total amount was 0.1% by weight based on the pure dye.

Use Example 2 Using this dye (II), an ink having the following composition was prepared.

Diethylene glycol 20% N-methyl-
2-Pyrrolidone 15% Dye (■) 5% Ion-exchanged water 60% T1 to T6 were investigated in the same manner as in Example 1. All of these showed excellent results similar to Example 1.

Example 3 Dye 3 exemplified in the specification was synthesized in the same manner as in Example 1.

After thoroughly mixing and dissolving this dye 3 (10 parts by weight) and ion exchange water (90 parts by weight) in a container, an anion exchange resin layer (DOWEX 66, MWA-1, manufactured by Dow Chemical Company) - Purification is carried out by passing through. Next, the filtrate is concentrated to dryness using an evaporator to obtain powdered dye (III).

When the concentration of sulfate radicals contained in this dye was measured using an ion chromatography device, the total amount was 0.04% by weight based on the pure content of the dye.

Usage Example 3 Using this dye (m), an ink having the following composition was prepared.

Polyethylene glycol 20% N-methyl-
2-Pyrrolidone 15% Dye (■) 5% Ion-exchanged water 60% T1 to T5 were investigated in the same manner as in Example 1. All of these showed excellent results similar to Example 1.

Example 4 After thoroughly mixing and dissolving the dye 2 (10 parts by weight) and ion-exchanged water (90 parts by weight) in a container, sodium sulfate was added to this aqueous solution and stirred to salt out the dye. .

Next, the precipitate was collected by filtration, washed with a pure aqueous solution of sodium sulfate, and dried. A predetermined amount of this dry solid is dissolved in methyl cellosolve and allowed to stand for an extended period of time. After that, a filtration process is performed.

Ta.

Usage Example 4 Using this dye (IV), an ink having the following composition was prepared.

Ethylene glycol 20% dye
5% ion exchange water
75% T1 to T5 were examined in the same manner as in Example 1. All of these showed excellent results similar to Example 1.

Example 5 Dye 4 exemplified in the specification was synthesized in the same manner as in Example 1.

This Dye 4 (10 parts by weight) and ion-exchanged water (90 parts by weight) were thoroughly mixed and dissolved in a container, and then sodium chloride was added to this aqueous solution and stirred to salt out the dye. Next, the precipitate was collected by filtration, washed with a pure aqueous solution of sodium chloride, and dried. A predetermined amount of this dry solid is dissolved in ion-exchanged water.

This solution was then mixed with the ion retarding resin Retardion 11.
-8 (manufactured by Dow Chemical Company). The first obtained filtrate is concentrated to dryness using an evaporator to obtain powdered dye (V).

When the concentration of sulfate groups contained in this dye (■) was measured using an ion chromatography device, the total amount was 0.03% by weight based on the pure dye.

Use Example 5 Using this dye (v), an ink having the following composition was prepared.

Ethylene glycol 20% glycerin
5% Dye (v) 5% Ion exchange water 70% T1 to T6 were investigated in the same manner as in Example 1. All of these showed excellent results similar to Example 1.

Usage Examples 6 to 9 Each color ink adjusted in Usage Examples 2 to 5 was individually filled into a felt pen, and after removing the cap and leaving it for 10 days, I wrote on paper and the ink was smooth and there was no smearing. I was able to write it down.

Comparative Example 1 Ink was prepared in the same manner as in Usage Example 1 using Supranor Fast Black VLG (manufactured by Bayer), and T1~
When T5 was examined, insoluble matter was found to be precipitated in the ink after one month of ink storage.

When the concentration of sulfate radicals contained in this dye was measured using an ion chromatography device, the total amount was 7.5% by weight based on the pure dye. Further, at T2, ink often failed to be ejected, and the driving voltage had to be changed (voltage increased). In T3, it was observed that the orifice became clogged and the ink ejection became unstable after being left for one month.

Comparative Example 2 Ink was prepared in the same manner as in Usage Example 1 using Thuganol-Fast Red 3B (manufactured by Chugai Kasei Co., Ltd.), and T.
When examining T5, insoluble matter was found to be precipitated in the ink after one month of ink storage.

When the concentration of sulfate radicals contained in this dye was measured using an ion chromatography device, the total amount was 6.2% by weight based on the pure dye. Further, at T2, ink often failed to be ejected, and the driving voltage had to be changed (voltage increased). In T3, it was observed that the orifice was clogged and the ink ejection became unstable after being left for one month.

Table 1

Claims (4)

[Claims] (1) A water-soluble dye having a structure represented by the following general formula (I) and containing 0.0001 to 3% by weight of sulfate groups as impurities. ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (However, in the above formula, A and B are unsubstituted or substituted benzene rings,
(represents a naphthalene ring, m represents 0 or 1, M represents an alkali metal, ammonium or amines) (2) The water-soluble dye according to claim 1, wherein the sulfate radical is contained in an amount of 0.0001 to 1.2% by weight. (3) The process of synthesizing a water-soluble dye represented by the following general formula (I) and the concentration of sulfate groups contained in the dye being 0.
1. A method for producing a water-soluble dye, comprising a step of adjusting the amount to 0.0001 to 3% by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (However, in the above formula, A and B are unsubstituted or substituted benzene rings,
(represents a naphthalene ring, m represents 0 or 1, M represents an alkali metal, ammonium or amines) (4) The method for producing a water-soluble dye according to claim 3, wherein the concentration of the sulfate radical is adjusted to 0.0001 to 1.2% by weight.