JPS62250066A - Water-soluble dye and production thereof - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [X is 1-4C alkylcarbonylamino, allylcarbonylamino, 1-4C alkylsulfonylamino, allylsulfonylamino, (1-4C alkyl- substituted)carbonamido, -SO3M (M is alkali metal, ammonium or amine), etc.; R<1> is H, 1-8C alkyl, 2-8C alkylcarbonyl, 1-4C alkylsulfonyl, allylsulfonyl or -CH2SO3M; R<2> is H or 1-8C alkyl; n is 0 or 1] 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. PREPARATION:The amine of formula III is diazotized in a mineral acid and coupled with the amine of formula IV to obtain a monoazo compound of formula V, which is diazotized in a mineral acid and coupled with the naphthol compound of formula VI.

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.

[Prior Art] The inkjet recording method uses 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, and a method that heats the ink and uses the pressure generated at that time. In this method, ink droplets are formed and some or all of them 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 recording liquids.

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.

(composition) The above objects are achieved by the following invention.

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

03M (wherein, R1
is a hydrogen atom ζ alkyl group having 1 to 8 carbon atoms, 2 to 8 carbon atoms
an alkylcarbonyl group, an alkylsulfonyl group having 1 to 4 carbon atoms, an allylsulfonyl group or -CH2SO3M
R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. However, when X is a -SO3M group, R
1 and R2 do not have a hydrogen atom at the same time. M represents an alkali metal, ammonium or amines, n is 0
Furthermore, the present invention provides a process for synthesizing a water-soluble dye represented by the following general formula (1), and a process for synthesizing a water-soluble dye represented by the following general formula (1) so that the concentration of sulfate groups contained in the dye is 0.0001 to 3% by weight. This is a method for producing a water-soluble dye characterized by including a step of adjusting.

03M (wherein, R1
is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and 2 to 8 carbon atoms.
an alkylcarbonyl group, an alkylsulfonyl group having 1 to 4 carbon atoms, an allylsulfonyl group or -CH2SO3M
R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. However, when X is a -503M group, R
1 and R2 do not have a hydrogen atom at the same time. M represents an alkali metal, ammonium or amines, n is 0
or l) [Function] As a result of extensive studies, the present inventor has found that the dye represented by the general formula (I) has excellent performance as a dye used in recording ink, especially light resistance and water resistance. It has been found that the dye has good solubility and color tone, and furthermore, the concentration of sulfuric acid radical (SOI-) contained in this dye is 0.0001% to 3% by weight, preferably 0.0001% to 1% by weight. By adjusting the amount to 2% by weight, it is possible to prepare an ink with excellent stability that does not cause clogging of nozzles, orifices, etc. even during use and long-term storage, despite the high concentration of the dye. The present invention was completed based on this knowledge.

Specific examples of the dye represented by general formula (1) of the present invention are listed below.

03Na o 3Li No, 3 S03Li The dyes of the present invention are as described in, for example, Thin 1) Yutaka, "New Dye Chemistry" (published December 21, 1970), Gihodo, page 397, line 27 to page 398, line 19, etc. It can be manufactured by the following method according to the description.

Amines represented by the following general formula (II) ...[1] (in the formula, X represents the above content) are diazotized using sodium nitrite, etc. in a mineral acid such as hydrochloric acid or sulfuric acid. Thereafter, it is coupled with an amine represented by the following general formula (m) O3H to obtain a monoazo compound represented by the following general formula (IV) 03H (wherein X represents the above content).

After diazotizing this monoazo compound in a mineral acid such as hydrochloric acid or sulfuric acid using sodium nitrite, etc., the following general formula [v
] (In the formula, R1, R2 and n represent the above contents) It can be easily obtained by coupling with a naphthol.

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 osmosis, acid precipitation, chemical treatment, and electrodialysis. etc., commonly known methods 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. Moreover, 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 has 2 to 6 carbon atoms, such as ethylene glyconyl, 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, 1, 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 in the range of 0 to 95% by weight, preferably 10 to SO, and more preferably 20 to 50% by weight based on the total weight of the ink. be.

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.

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

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 5 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 caustic soda, ice and the above diazo solution to this and 3℃
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 caustic soda were added thereto, and coupling was performed under weak alkalinity at a temperature of 2 to 5°C.

After thorough stirring under the same conditions, common salt was added to salt out the dye. The precipitate was collected by filtration and dried.

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 (I) 5% Ion-exchanged water 60% This ink is used to generate droplets by applying thermal energy to the ink in the recording head to create an on-demand type multi-head (discharge 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, the mixture is concentrated to dryness using an evaporator to obtain powdered dye (II).

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.

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

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

After sufficiently mixing and dissolving this dye 3 (10 parts by weight) and ion exchange water (90 parts by weight) in a container, the anion exchange resin layer (Dowex 66, MWA-1, Dow Chemical
Purification is carried out by passing it through a

Next, the filtrate is concentrated to dryness using an evaporator to obtain a powdered dye (m).

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 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.

When the concentration was measured using an ion chromatography device, the total amount was 0.6% based on the pure dye content.

Usage Example 4 Using this dye (TV), 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.

Then, add 1 liter of this solution to the ion retardation resin Retardion.
-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 radicals contained in this dye (V) 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-exchanged water 70% T1 to T5 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, when writing on paper, 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 T, ~
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 An ink was prepared in the same manner as in Usage Example 1 using Thuganol-Fast Red 3B (manufactured by Chugai Kasei Co., Ltd.), and T1
- When Tls was investigated, 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 T and a, it was observed that the orifice became clogged and the ink ejection became unstable after being left unused for one month, as shown in 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] (In the formula, represents an amino group, a carbonamide group which may be substituted with an alkyl group having 1 to 4 carbon atoms, a sulfonamide group which may be substituted with an alkyl group having 1 to 4 carbon atoms, or a group of -SO_3M;
^1 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and 2 carbon atoms
-8 alkylcarbonyl group, C1-4 alkylsulfonyl group, allylsulfonyl group or -CH_2S
It represents a group O_3M, and R^2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. However, X is −SO_3M
In the case of the group, R^1 and R^2 do not have a hydrogen atom at the same time. M represents an alkali metal, ammonium or amines, n represents 0 or 1) (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] (In the formula, represents an amino group, a carbonamide group which may be substituted with an alkyl group having 1 to 4 carbon atoms, a sulfonamide group which may be substituted with an alkyl group having 1 to 4 carbon atoms, or a group of -SO_3M;
^1 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and 2 carbon atoms
-8 alkylcarbonyl group, C1-4 alkylsulfonyl group, allylsulfonyl group or -CH_2S
It represents a group O_3M, and R^2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. However, X is −SO_3M
In the case of the group, R^1 and R^2 do not have a hydrogen atom at the same time. M represents an alkali metal, ammonium or amines, n represents 0 or 1) (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.