JPH10120926A - Dye, inkjet recording ink, and color inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dye, having a high chromaticness, capable of satisfying color reproducibility, light fastness, water resistance, etc., and suitably used for color ink jet recording by using a magenta dye having a specific structure. SOLUTION: This dye is a magenta dye represented by formula I [A is any group represented by formula II or III [R1 is H, a 1-3C lower alkyl or a lower lakoxy; M is H, and alkali metal or organic amines); R2 is CO-CH3 , CO-Ph or CO-Ph-C1] and is obtained by a well-known method. When the dye is used as an ink for ink jet recording, 0.5-5wt.% dye is preferably contained in the ink. A specific acetylene glycol is preferably contained as a penetrant in the ink for ink jet recording. Thereby, the color ink jet recording method for providing a bright image and excellent in fastness can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magenta dye used in aqueous ink, an ink containing the dye, and a color ink jet recording method.

[0002]

2. Description of the Related Art When a color image is formed by using an ink jet recording method, at least a yellow ink, a magenta ink and a cyan ink are generally used.
These inks have appropriate physical properties such as viscosity and surface tension, and have excellent resolution or color tone reproducibility in color imaging not only for inkjet recording paper but also plain paper. In addition, it is required to provide an image with good image quality, to provide an image having excellent fastness such as light fastness and water fastness, to be excellent in storage stability, and not to cause clogging.

Many of these performances are satisfied by using an aqueous ink containing water or a mixture of water and a water-soluble organic solvent as a main solvent. In particular, color tone reproducibility, vividness,
Lightfastness, waterfastness and the like largely depend on the colorant, and various dyes and pigments have been studied conventionally. Above all, magenta ink, especially vividness and color tone reproducibility,
Further, although light resistance cannot be sufficiently satisfied, it has been studied conventionally. For example, JP-A-59-78273 and JP-A-59-131657 disclose inks containing a monoazo magenta dye having a specific structure.
It is disclosed that the required characteristics of ink jet recording are satisfied. Japanese Patent Application Laid-Open No. 6-22847 discloses that a good color tone and light fastness can be realized by using a monoazo magenta dye having a specific structure and an ink.

[0004]

However, these magenta dyes have the problem that the color tone is strongly reddish and the chroma is low. On the other hand, the magenta dye having a xanthene skeleton has good color tone and chroma, but has a problem of poor light fastness. Accordingly, none of the conventionally proposed magenta dyes and inks has been found to satisfy clear color tone and color reproducibility, light resistance, water resistance and clogging reliability. Furthermore, the problem that bleeding occurs on special paper due to high humidity is also being considered as a new problem. Further, in a color inkjet recording method of forming a color image using yellow ink, magenta ink, and cyan ink, the color tone of magenta,
Due to the low saturation, the color reproducibility of single colors and mixed colors is insufficient, or the provision of color printing with high image quality and high robustness as a color recording method such as low light resistance has not been realized yet.

Accordingly, an object of the present invention is to provide a magenta dye, a magenta ink, and a color ink jet recording method having a clear image and excellent fastness, which have high chroma and satisfy color reproducibility, light fastness, water fastness and other properties. Is to do.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted various studies to achieve the above object. As a result, by using a magenta dye having a specific structure, color reproduction, light fastness,
It has been found that water resistance and other properties can be satisfied, and the present invention has been achieved.

That is, a magenta dye having the structure represented by the general formula [I], and an ink containing the dye.

[0008]

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(Where A is selected from the following two)

[0010]

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[0011]

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Wherein R 1 is selected from a hydrogen atom, a lower alkyl group having 1 to 3 carbon atoms, and a lower alkoxy group;
R2 is selected from the following three)

[0013]

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[0014]

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[0015]

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(Wherein, M is selected from a hydrogen atom, an alkali metal, and an organic amine) A color ink jet recording method using at least a yellow ink, a magenta ink, and a cyan ink, wherein the magenta ink is the present invention Is a color ink jet recording method containing the dye of formula (1).

Specific examples of the dye represented by the general formula [I] of the dye of the present invention are shown below.

[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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These dyes exhibit superior performance with respect to the above-mentioned various properties as compared with conventionally known dyes having a similar structure. The present application differs from the conventionally known magenta having a similar structure in that the phenyl group that forms an azo bond with H acid has two sulfone groups or carboxyl groups at the para position. It has been found that very excellent color tone and light fastness can be satisfied by the presence of this substituent. Such a dye represented by the general formula [I] of the present invention can be produced by a method similar to a conventionally used monoazo dye or a dye similar thereto. For example, it can be produced by a method according to the production method of columns 11 to 12 of JP-A-59-78273. That is, amines represented by the following formulas 23 and 24 (wherein R1 is each selected from a hydrogen atom, a lower alkyl group having 1 to 3 carbon atoms, and a lower alkoxy group) can be used in a dilute acid such as a salt or sulfuric acid. To diazotize using sodium nitrite or the like.

[0026]

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[0027]

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Thereafter, a compound represented by the following general formula [III]:
(Wherein R2 is selected from the above-mentioned chemical formulas 13, 14 and 15).

[0029]

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According to the present invention, it is possible to obtain an ink having good color reproducibility, high color development, and satisfying light resistance, water resistance, clogging property, storage reliability and other properties.

Such an ink can be adjusted as follows. First, the amount of the dye added is appropriately determined according to the reliability and required characteristics of the ink.
Preferably it is in the range of 0.5 to 5% by weight. These dyes are preferably used alone or in combination of two or more, but other direct dyes and acid dyes can also be used in combination.

Further, the solvent used in the ink of the present invention is water or a mixture of water and a water-soluble organic solvent, and a particularly preferable one is a mixture of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent used by mixing with water include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2
Polyhydric alcohols such as 6-hexanetriol and glycerin; ethers of polyhydric alcohols such as ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether and triethylene glycol monobutyl ether; formamide, dimethylformamide, diethanolamine, triethanolamine Nitrogen-containing solvents such as ethanolamine, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidone and N-methyl-2-pyrrolidone; and sulfur-containing solvents such as thiodiglycol and dimethylsulfoxide.

These solvents may be used alone, or 2
More than one kind may be used in combination, and the content thereof is in the range of 3 to 40% by weight, preferably 3 to 30% by weight based on the total amount of the ink. When the content is less than 3% by weight, it is not enough to prevent clogging at the nozzle tip, and the content is 40% by weight.
When it exceeds, bleeding occurs, a clear image cannot be obtained, and the image quality deteriorates.

Further, in order to promote the drying property of the printed matter after image formation, the ink of the present invention contains lower alcohols such as ethanol, 1-propanol and 2-propanol,
It is preferable to include an anionic surfactant such as a fatty acid salt and an alkyl sulfate salt, and a nonionic surfactant such as an acetylene glycol, a polyoxyethylene alkyl ether and a polyoxyethylene fatty acid ester. The content of lower alcohols is 2 to the total amount of ink.
10 to 10% by weight, preferably 2 to 6% by weight;
The surfactant is desirably in the range of 0.01 to 3% by weight. If the content of each is less than this, the effect of promoting the drying property is not sufficient, and if it is more than this, bleeding occurs, and in the ink jet recording method, the ink ejection (or flying) state is adversely affected, and the image quality is degraded. descend. The penetrant of the ink of the present invention is represented by the following general formula [II]

[0035]

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It is preferable to contain acetylene glycol represented by the formula (1) and a lower alkyl ether of a polyhydric alcohol. Specifically, acetylene glycol is available from Nissin Chemical Co., Ltd.
Olfine E1010, Olfine STG, and the like, and examples of the alkyl ether include triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

Further, the ink of the present invention may contain a water-soluble polymer or water-soluble resin, an antifoaming agent, a pH adjusting agent, a fungicide, etc., if necessary.

Ink production using the above-mentioned components can be carried out according to a conventional method. For example, there is a method in which each component is sufficiently mixed and dissolved, filtered under pressure through a membrane filter having a pore size of 0.8 μm, and then deaerated using a vacuum pump to prepare an ink.

The color ink jet recording method of the present invention is a method in which recording is performed using the above-mentioned ink, and any conventionally known method can be used as a head discharge method. An excellent color ink jet recording can be performed by a method of ejecting liquid droplets or a method using thermal energy.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to examples and comparative examples.

First, the magenta dye of the present invention is synthesized.

<Synthesis Example 1> Synthesis of dye of formula 16 4-methoxyaniline-3,6-disulfonic acid 26.9
g was added to 346 cc of 3% hydrochloric acid and stirred for 3 hours to obtain a uniform slurry. 200 g of ice was added thereto, and the mixture was cooled to 3 ° C. Separately, 7.3 g of sodium nitrite is dissolved in 73 cc of water,
This was added to the slurry. After stirring for 1 hour at 3 ° C. to diazotize, 3 g of sulfamic acid was added to eliminate the remaining sodium nitrite. On the other hand, after adding 43.9 g of N- (4-chloro-benzoyl) H acid to 850 cc of water,
20 g of a 25% aqueous solution of sodium hydroxide was added to adjust the pH to 9, and dissolved. 800 g of ice was added thereto, and the temperature was adjusted to 3 ° C., and then the diazo solution, 200 g of ice and 25% sodium hydroxide 35c
While maintaining the pH at 8-10 and the temperature at 2-5 ° C, coupling was carried out by alternately adding c. After stirring at the same temperature for 5 hours, 500 g of common salt was added to salt out the product. After filtering the precipitated product, it was washed with 500 cc of a 20% saline solution to obtain a wet cake. After desalting this wet cake, it was dried to obtain 65 g of the dye of Chemical formula 8.

<Synthesis Example 2> Synthesis of dye of formula 17 4-methoxyaniline-3,6-disulfonic acid 26.9
g was added to 346 g of 3% hydrochloric acid and stirred for 3 hours to obtain a uniform slurry. 200 g of ice was added thereto, and the mixture was cooled to 3 ° C. Separately, 7.3 g of sodium nitrite is dissolved in 73 cc of water,
This was added to the slurry. After diazotization by stirring at 3 ° C. for 1 hour, 3 g of sulfamic acid was added to eliminate the remaining sodium nitrite. On the other hand, N-benzoyl H acid 4
After adding 2.3 g to 850 cc of water, 20 g of a 25% aqueous solution of sodium hydroxide was added to adjust the pH to 9, and dissolved. 800 g of ice was added thereto, and the temperature was adjusted to 3 ° C.
00 g and 35 cc of 25% caustic soda at pH 8-1
0, while maintaining the temperature at 2-5 ° C, coupling was carried out by alternately adding. After stirring at the same temperature for 5 hours, 500 g of salt
Was added to salt out the product. After filtering the precipitated product, it was washed with 500 cc of a 20% saline solution to obtain a wet cake. The wet cake was desalted and dried to obtain 62 g of the dye of Chemical formula 9.

<Synthesis Example 3> Synthesis of dye of formula 18 2-aminotoluene-3,6-disulfonic acid 26.7 g
Was added to 380 g of 3% hydrochloric acid and stirred for 3 hours to obtain a uniform slurry. 200 g of ice was added thereto, and the mixture was cooled to 3 ° C.
Separately, 7.3 g of sodium nitrite was dissolved in 73 cc of water, and this was added to the slurry. After diazotization by stirring at 3 ° C. for 1 hour, 3 g of sulfamic acid was added to eliminate the remaining sodium nitrite. On the other hand, N-acetyl H acid 36.1
g was added to 750 cc of water, and 70 g of a 25% aqueous solution of sodium hydroxide was added to adjust the pH to 9 and dissolved. Ice 80
After adding 0 g and adjusting the temperature to 3 ° C., the diazo solution and ice 200 g
Further, 35 cc of 25% caustic soda was added alternately while maintaining the pH at 8-10 and the temperature at 2-5 ° C. to perform coupling. After stirring at the same temperature for 5 hours, 500 g of common salt was added to salt out the product. After filtering the precipitated product, 20
The resultant was washed with 500 cc of a 50% saline solution to obtain a wet cake. After desalting this wet cake, it was dried to obtain 54.4 g of an Na salt of the dye of Chemical Formula 10. Further, acid precipitation was performed, and 5% ammonia water was added to obtain an ammonium salt.

As described above, the other magenta dyes of the present application can be similarly synthesized by selecting the starting materials.

The inks of the examples and comparative examples were prepared by the above-described ink manufacturing method at the compounding ratios shown in Table 1. In addition, each component of the ink shown in the table indicates the weight% of each component with respect to the total amount of the ink, and the remaining amount is water. In the comparative examples, the following magenta dyes which have been conventionally studied are represented by the following Chemical formula 27,
Chemical formula 28 was used.

[0047]

[Table 1]

[0048]

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[0049]

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Table 1 is supplemented as follows.

TEGmBE Triethylene glycol monobutyl ether DEGmBE Diethylene glycol monobutyl ether TEA Triethanolamine KOH Potassium hydroxide Orfin E1010, Olfin STG is a product of Nissin Chemical Co., Ltd. Proxel XL-2 is a product of Zeneca Corporation. Tests 1 to 5 were evaluated using the inks of Examples 1 to 9 and Comparative Examples 1 to 4 obtained as described above, the image forming apparatus and the recording paper shown below.

(Image Forming Apparatus) Using a prototype inkjet head (nozzle diameter: 30 μm, 64 nozzles) of an on-demand type which performs recording by generating droplets by vibrating action of a piezoelectric element, a driving frequency of 7.2 kHz and a piezoelectric element Drive voltage 25V, resolution 36
Under the condition of 0 dots / inch, the ink weight is 0.04 μg /
Printing was performed with dots.

(Recording paper) (1) Superfine paper for ink jet (Epson Sales Co., Ltd.) (2) Glossy film for ink jet (Epson Sales Co., Ltd.) (3) Xerox 4024 (Xerox) (4) Xerox P (Fuji Xerox Co., Ltd.) (5) Canon PB Paper (Canon Sales Co., Ltd.).

<Test 1: Hue> For each of the inks of the examples and comparative examples, using the image forming apparatus,
Magenta solid printing (solid printing) was performed on the recording paper of (5).

The hue of a solid printed image (3 × 3 cm) of each ink obtained was measured by CIE (Commision Inte
The L ^* a ^* b ^* color system of the color difference display method specified by Rnational de l'Eclairage) was measured using a Macbeth CE-7000 spectrophotometer (manufactured by Macbeth), and the measured values and the following table were used. The color difference from the color tone reference value of ISO 2845-1975 described in No. 2 was obtained from the following equation (i).

[0056]

[Table 2]

ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (i) The obtained recording papers (1) to (5) The hue was determined from the average value of the color difference ΔE ^* ab) according to the following criteria. Judgment Criteria When the color difference ΔE ^* ab of magenta is 10 or less in each case. ◎ When it is more than 10 and 20 or less.

<Test 2: Light fastness> A solid print sample of the recording papers (1) and (4) obtained in Test 1 was placed in a transparent plastic cellophane case and left for 30 days in sunlight. ΔE ^* ab before and after the test was determined according to the following criteria. ΔE * ab before and after the test was determined in the same manner as in Test 2. Judgment Criteria When the color difference ΔE ^* ab is less than or equal to 20 ◎ When it is more than 20 and less than or equal to 30 ○ When it exceeds 30 ×

<Test 3: Recoverability of nozzle clogging> Each head is filled by repeating cleaning with each ink, and it is confirmed by printing that ink is being ejected from each nozzle. Left for one week in the environment. After the standing, the power of the printer was turned on, and the number of cleaning operations required until all the nozzles could be discharged was determined according to the following criteria. ◎: once ○: 2-3 times ×: 4 times or more

<Test 4: Bleeding of special paper and special film printing> White characters are printed on the recording papers (1) and (2) using 100% duty, 200%, and 300% solids. The printed pattern was printed. This is 4
After leaving in an environment of 90% RH at 0 ° C. for 2 hours, bleeding of a printed portion was determined according to the following criteria. ：: No bleeding ○: Slight bleeding ×: Bleeding The results of the above Tests 1 to 4 are shown in Table 3.

[0061]

[Table 3]

[0062]

According to the present invention, magenta dyes and inks which are clear, have a good color tone, and are excellent in light resistance are obtained. Also,
A printed matter having good storability without bleeding due to high humidity on a special paper was obtained. Furthermore, the clogging recovery property was good, and reliability and high quality could be realized.

Claims (7)

[Claims] 1. A magenta dye having a structure represented by the following general formula [I]. Embedded image (Where A is selected from the following two): Embedded image (Wherein, R1 is selected from a hydrogen atom, a lower alkyl group having 1 to 3 carbon atoms, and a lower alkoxy group, and R2 is selected from the following three): Embedded image Embedded image (Where M is selected from a hydrogen atom, an alkali metal, and an organic amine) 2. An ink for ink-jet recording comprising the dye according to claim 1 in an amount of 0.5 to 5% by weight. 3. The ink for ink jet recording according to claim 2, wherein the penetrant contains acetylene glycol represented by the general formula [II]. Embedded image (Wherein, R1, R2, R3 and R4 each independently represent a C1-6 alkyl group, and n + m represents 0 to 30) 4. The ink jet recording ink according to claim 2, further comprising a polyhydric alcohol lower alkyl ether as a penetrant. 5. The ink for ink-jet recording according to claim 2, wherein the dye has a structure shown below. Embedded image 6. The ink jet recording ink according to claim 2, wherein the dye has a structure shown below. Embedded image 7. A color ink jet recording method using at least a yellow ink, a magenta ink, and a cyan ink, wherein the magenta ink contains the dye according to claim 1. Description: