JP3341968B2 - Ink composition and inkjet recording method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition and an ink jet recording method using the same.

2. Description of the Related Art Ink used in an ink jet recording system includes:
Generally, various dyes are dissolved in water, an organic solvent, or a mixture thereof. However, compared to inks for writing implements such as fountain pens and ballpoint pens, inks used for ink-jet recording require more strict performance in various characteristics.

[0003] The performance required of such ink for ink jet recording is, for example, that physical properties such as viscosity and surface tension are appropriate, high optical density, clear color tone and image are provided, water resistance, Examples include providing an image having excellent fastness such as light fastness, being excellent in storage stability, being unlikely to cause nozzle clogging, and being excellent in odor and safety.

Most of these properties are satisfied by using an aqueous ink obtained by dissolving a water-soluble dye in water or a mixture of water and a water-soluble organic solvent. Therefore, the ink used for the ink jet recording method has been repeatedly improved based on the aqueous ink.

For example, in order to quickly fix ink on paper, attempts have been made to improve ink permeability. In this regard, Japanese Patent Application Laid-Open No. 4-183761, U.S. Pat. No. 5,183,502, and U.S. Pat.
No. 67 discloses that diethylene glycol monobutyl ether is added as an ink component, and that both a glycol ether and a nonionic acetylene glycol-based surfactant are added. But,
In these penetrated inks, since the ink penetrates into the paper, in some cases, sufficient color developability and image density cannot be obtained, and a clear image may not be obtained. On the other hand, if the dye concentration is increased to solve this problem, the solid content increases, so that precipitation near the nozzle is likely to occur, which may cause clogging. If the amount of the wetting agent is increased to further prevent clogging, the viscosity of the ink increases,
Particularly, there is a possibility that the ink jet method is disadvantageous.

[0006] In addition, performances such as color tone, water fastness and light fastness largely depend on the characteristics of the dye, and thus various dyes have been studied. Further, recently, among various ink properties, a demand for water resistance of printed matter has been increasing. For example, JP-A-3-79681
JP, JP-A-3-91577, JP-A-6-73
No. 320 and JP-A-6-172668 indicate that an ink composition having good water resistance can be obtained by using a specific dye.

However, it can be said that these ink compositions leave room for improvement in various characteristics.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an ink composition which satisfies the characteristics required for an ink-jet ink, particularly an ink composition which is capable of recording high quality images on plain paper and has excellent water resistance of recorded images. Its purpose is to provide.

The present inventors have now found that the above objects can be achieved by using a specific dye.

That is, the present invention is an ink composition containing a dye represented by the following general formula (I).

[0011]

Embedded image [In the above formula, M represents H, an alkali metal, optionally substituted ammonium, morpholinium, or piperidinium, and R ¹ represents H, NH ₂ , or COOM (where,
M represents the same meanings as defined above), R ² is COOM or -P (= O) n- (OM ) 2 ( wherein,, M are as defined above, n represents 0 or 1) Wherein R ³ represents H, COOM or SO ₃ M (where M is as defined above), and R ⁴ and R ⁵ are each independently H, alkyl having 1 to 6 carbon atoms Group or 1 to carbon atoms
6 represents an alkoxyl group, R ⁶ represents H, an optionally substituted phenyl group, an alkylcarbonyl group, or an alkyl group optionally substituted by a hydroxyl group or an alkoxyl group, and m represents 0 or 1. ]

[0012]

DETAILED DESCRIPTION OF THE INVENTION In the present specification, a group or an alkyl group as a part of a group may be linear or branched.

Here, in the general formula (I), M is
H, represents an alkali metal, an optionally substituted ammonium, morpholinium, or piperidinium. The alkali metal represented by M is preferably lithium, potassium or sodium. Further, the optionally substituted ammonium substituent represented by M is preferably an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms) which may be optionally substituted with a hydroxyl group.

Examples of amines which form an ammonium wherein M may be substituted include, for example, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, diisopropylamine, butylamine, Isobutylamine, sec-butylamine, tert-butylamine and dibutylamine. The dye used in the present invention is an ammonium salt,
It does not need to be a single salt of a substituted ammonium salt, a morpholinium salt, or a piperidinium salt, and may be a mixture with an alkali metal salt or the like. In that case,
It is preferable that the ratio of M which is an alkali metal salt to the number of M of the dye represented by the general formula (I) is 50% or less.

The dye represented by the general formula (I) can itself form a recording having excellent water resistance. Further, by forming a salt with the amines, the water resistance can be further improved. The reason is presumed as follows. That is, the amines are generally volatile, and after recording, the amines are volatilized from the paper. As a result, M in the general formula (I) becomes H and forms a carboxyl group or a phosphate group. Since the dissociation constants of the carboxyl group and the phosphate group are generally small, even if water adheres to the recorded paper, the dye represented by the general formula (I) reappears in the adhered water. It becomes difficult to dissolve. Thereby, it is considered that the water resistance of the recording is further improved.

In the general formula (I), one or more hydrogen atoms of the phenyl group represented by R ⁶ may be substituted, and a preferable example of the substituent is a carboxyl group. In some cases, it may be an ammonium salt. The alkyl group portion of the alkylcarbonyl group represented by R ⁶ preferably has 1 to 1 carbon atoms.
And more preferably an alkyl group having 1 to 4 carbon atoms. One or more hydrogen atoms of this alkyl group may be substituted, and examples of the substituent include a hydroxyl group or an alkoxyl group (preferably an alkoxyl group having 1 to 6 carbon atoms, more preferably an alkoxyl group having 1 to 4 carbon atoms). Alkoxyl group).

Preferred specific examples of the compound represented by the above general formula (I) used in the present invention include those described in the following table.

[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]

Embedded image The compound represented by the general formula (I) can be prepared by a known method (for example,
It can be manufactured through a diazotization and coupling step described in Yutaka Hosoda, “Shin Dye Chemistry” (Gihodo).

A specific production method is as shown in the following scheme.

[0026]

Embedded image By reacting a diazo compound represented by the formula (II) with a compound represented by the formula (III) in water at a temperature of about 0 to 5 ° C for 40 minutes to 2.5 hours, I
The monoazo compound V) can be obtained.

Further, the compound of the formula (IV) is diazotized according to a conventional method to obtain a compound of the formula (V), and this compound and the compound of the formula (VI) are converted substantially under the same conditions as those for obtaining the monoazo compound. By reacting under the conditions of formula (V)
The disazo compound of II) can be obtained.

Further, the compound of the formula (VII) is diazotized according to a conventional method to obtain a compound of the formula (VIII), and this compound and the compound of the formula (IX) are dissolved in water at about 5 to 10 ° C. By reacting at a temperature of 1 to 2 hours, a trisazo compound of the formula (I) can be obtained.

The content of the dye represented by the general formula (I) in the whole ink is determined depending on the kind of the solvent component, the characteristics required for the ink, and the like. Its content is preferably 1-1.
0% by weight, more preferably 2 to 8% by weight.
When the amount of the dye of the general formula (I) is within the above range,
Good image density and image quality, and good printing characteristics without clogging are obtained.

According to a preferred embodiment of the present invention, the ink composition preferably further comprises a nonionic acetylene glycol surfactant and a glycol ether. By these additions, dots with high roundness can be obtained without lowering the color developability. Furthermore, sufficient dryness is satisfied and high quality printing is obtained.

As the nonionic acetylene glycol-based surfactant suitably used in the present invention, for example, Surfynol 465, Surfynol TG, Surfynol 104 (above Air Products and Ch)
chemicals), and Surfynol TG is particularly preferred. The addition amount is preferably 0.05 to 3% by weight, more preferably 0.8 to 2% by weight. It is also preferable to add a nonionic surfactant such as a polyoxyethylene alkyl ether or a polyoxyethylene fatty acid ester as the surfactant.

The glycol ethers preferably used in the present invention include, for example, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monomethyl ether. Propylene glycol monobutyl ether. The added amount is preferably 3 to 30% by weight, more preferably 5 to 15% by weight.

Further, according to a preferred embodiment of the present invention,
The ink composition preferably contains a polyhydric alcohol. The addition of the polyhydric alcohol can preferably further improve the moisturizing effect and the effect of preventing clogging.

The polyhydric alcohols suitably used in the present invention include, for example, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol and propylene glycol;
Examples thereof include 1,3-propanediol, 1,5-pentanediol, 1,2,6-hexanetriol, and glycerin, which can be used alone or in combination of two or more. Its addition amount is 1 to 30% by weight, preferably 3 to 20%.
% By weight.

Further, according to a preferred embodiment of the present invention,
The ink composition preferably contains a nitrogen-containing cyclic compound. The addition of the nitrogen-containing cyclic compound can improve the water resistance of printing, the image quality, and the stability of the ink composition. In particular, these nitrogen-containing cyclic compounds, while improving the dissolution stability of the dye, printing stability,
It also functions as a color development aid and a water resistance aid, and is useful for the ink composition of the present invention.

Examples of the nitrogen-containing cyclic compound suitably used in the present invention include, for example, imidazolidinones (for example, 1,2)
3-dimethyl-2-imidazolidinone), pyrrolidones (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone), and caprolactams (eg, ε-caprolactam), alone or in combination of two or more. Can be used. The addition amount is 1 to 30% by weight, preferably 3 to 20% by weight.

According to a preferred embodiment of the present invention, the ink composition contains a monohydric lower alcohol such as ethanol, 1-propanol or 2-propanol in order to promote the drying property of the ink after image formation. And an anionic surfactant such as a fatty acid salt or an alkyl sulfate salt. The content of lower alcohols is 2 to 10% by weight, preferably 2 to 6% by weight based on the total amount of the ink.
%, And the content of the surfactant is preferably in the range of 0.01 to 2% by weight based on the total amount of the ink.

Further, the ink composition of the present invention may contain, if necessary, amines such as thiodiglycol, triethanolamine and diethanolamine, a fluorine-based or silicon-based surfactant, a water-soluble polymer, a water-soluble resin, Antifoam,
A pH adjuster, a fungicide and the like may be added.

The ink composition of the present invention can be produced according to a conventional method. For example, the ink can be manufactured by sufficiently mixing and dissolving the respective components, filtering under pressure through a membrane filter having a pore diameter of 0.8 μm, and then performing degassing treatment using a vacuum pump to prepare an ink.

The ink composition of the present invention can be used most effectively in a conventionally known ink jet recording apparatus, but is not limited thereto.
It can be used even when used for devices such as recorders and pen plotters.

As the ink jet recording method, any of the conventionally known methods can be used. Particularly, in the method of ejecting liquid droplets by using the vibration of the piezoelectric element or the method of using thermal energy, excellent image recording is performed. It is possible.

[0042]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the examples do not limit the present invention. Synthesis Example of Dye: Compound No. 9 m-Aminobenzenephosphonic acid (87.0 g) was added to water (5
00 ml) with stirring. To this was added 35% hydrochloric acid (101.3 g), and the mixture was cooled to 0 ° C. To this solution, a 36% aqueous solution of sodium nitrite (105.4 g) was gradually added dropwise so that the liquid mixture did not exceed 5 ° C., and the mixture was stirred for 50 minutes to diazotize m-aminobenzenephosphonic acid. Thereafter, thiourea was added to the obtained aqueous solution, and excess nitrous acid was removed to obtain a diazo component-containing liquid. Meanwhile, 3
-Aminobenzoic acid (68.6 g) in methanol 800 m
and heated to 55 ° C. for dissolution to obtain a coupling component-containing solution. The coupling component-containing solution is
C., and the above-mentioned diazo component-containing solution was added dropwise thereto so that the liquid temperature did not exceed 5 ° C. After stirring at 3 to 5 ° C for 18 hours, the resulting precipitate was collected by filtration and washed with water to obtain a monoazo compound; m- (2-carboxy-4-amino-phenylazo) benzenephosphonic acid (about 125.3 g).

The obtained monoazo compound (64.2 g) was dispersed in water (700 ml), and dissolved by adding a 45% aqueous sodium hydroxide solution (35.6 g). 36
5% sodium nitrite aqueous solution (42.2 g)
And cooled. Further, add 20% hydrochloric acid (127.6 g) at 10 ° C.
And then stirred at 10 ° C. or lower for 80 minutes to diazotize the monoazo compound. Thereafter, sulfamic acid was added to the resulting aqueous solution to remove excess nitrous acid to obtain a diazo component-containing solution. On the other hand, 2.5-dimethoxyaniline (30.6 g)
Was dissolved in 600 ml of methanol to obtain a solution containing a coupling component. The coupling component-containing solution was cooled to 0 ° C. or lower, and the diazo component-containing solution was gradually added dropwise thereto while paying attention so that the liquid temperature did not exceed 5 ° C.
Stirred at 8 ° C. for 18 hours. The precipitate is collected by filtration, washed with water,
Disazo compound; m- (2-carboxy-4- (2.5
-Dimethoxy-4-aminophenylazo) phenylazo) benzenephosphonic acid (about 82.6 g) was obtained.

The obtained disazo compound (72.8 g) was dispersed in water (700 ml), and dissolved by adding a 45% aqueous sodium hydroxide solution. To this solution was added a 36% aqueous sodium nitrite solution (32.6 g), and the mixture was cooled to 5 ° C.
To this, 20% hydrochloric acid (82.0 g) was gradually added dropwise so that the liquid temperature did not exceed 10 ° C., and the disazo intermediate was diazotized by stirring at 10 ° C. or lower for 90 minutes. afterwards,
Sulfamic acid was added to the resulting aqueous solution to remove excess nitrous acid to obtain a diazo component-containing solution. On the other hand, gamma-acid (1-hydroxy-7-amino-3-naphthylsulfonic acid, (35.9 g) was added to water (600 ml), and
Dissolve in 5% aqueous sodium hydroxide solution (30.0 g),
The solution was cooled to 3 ° C. to prepare a coupler solution. The diazo component-containing solution prepared above was added dropwise while keeping the reaction temperature not higher than 8 ° C and maintaining the reaction pH at 8.5 or more by adding a 20% aqueous sodium hydroxide solution.
Stirred at 8 ° C for 4 hours. Crystals were precipitated by salt / acid precipitation and filtered, washed with water and dried to give Compound No.
Compound 9 (67.0 g) was obtained. This compound was dispersed in ion-exchanged water, purified and concentrated using a reverse osmosis membrane, and further purified using Compound No. 1 with ammonia water. The ammonium salt of 9 was obtained. Compound No. 1 to 8 and 10 to 23 were synthesized in the same manner as described above.

EXPERIMENTAL EXAMPLES The ink compositions of Examples and Comparative Examples were produced at the compounding ratios shown in Tables 1 and 2. The numerical values in Tables 1 and 2 represent the weight% of each component with respect to the total amount of the ink, and the balance is water.

[0046]

[Table 1]

[0047]

[Table 2] Among the ink compositions, No. 1 to 23 are the dyes according to the invention described in the above table. On the other hand, No. 24 is a dye outside the scope of the present invention and is a dye represented by the following formula.

[0048]

Embedded image The following evaluations were performed using the obtained ink compositions. In the evaluation test, the inkjet printer M
J-500 (manufactured by Seiko Epson Corporation) was used.

<Test 1: Water resistance> (1) EPP paper (Epson Sales Co., Ltd.) (acid paper), (2) XeroxP (Fuji Xerox Co., Ltd.)
Alphabet printing was performed on (neutral paper). Water droplets were dropped on the printed sample, and the state of the sample after air-drying was visually observed and evaluated as follows. ：: No change from the initial state. ：: As expected, the dye was dissolved, but the characters were clearly readable. Δ: There is bleeding, but characters can be read. ×: Characters cannot be read.

<Test 2: Image Quality> (1) EPP paper, (2) Xerox P, (3) Xe
rox 4024 (Xerox Co.), (4) Ri
Alphabet printing and / or graphic printing were performed on copy 6200 (Ricoh Co., Ltd.). The printed matter was visually evaluated as follows. ◎: No bleeding, high density. ：: Slight bleeding was observed, but there was no effect on the image, and the density was high. Or there is no bleeding, but the concentration is slightly low. Δ: Low bleeding but low density. X: The blur is conspicuous or the density is low.

<Test 3: Recovery from clogging> After the recording head of the printer was filled with ink, the recording head was left at 40 ° C. for one month while being shifted from the cap position. Thereafter, the number of cleanings until normal printing was possible was evaluated as follows. ：: 0 to 2 times. ：: 3 to 5 times. Δ: 5 to 10 times. ×: The recovery was not performed after performing up to 10 times.

<Test 4: Printing Stability> Continuous printing was performed using the self-check pattern mounted on the inkjet printer MJ-500, and the time during which printing was performed stably was evaluated as follows. ：: 24 hours or more. ：: 10 hours or more and less than 24 hours. X: Less than 10 hours.

<Test 5: Storage stability> MJ of printer
Filling the ink cartridge for -500 with ink, -3
Leave at 0 ° C. and 70 ° C. for 2 weeks. Before and after that, the physical properties of the ink, the change in color tone, and the presence / absence of foreign matter / precipitate were observed and evaluated as follows. ：: No change in physical properties and color tone, and no generation of foreign substances and precipitates. ×: Changes in physical properties and color tone, or generation of foreign matters and precipitates were observed. The above evaluation results were as shown in Tables 3 to 5.

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroko Hayashi 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Junko Takatsuna 3-chome, Yamato 3-chome, Suwa-shi, Nagano No. 5 Inside Seiko Epson Corporation (72) Inventor Masahiro Yatake 3-5 Yamato 3-chome, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Takashi Ono 4-chome Shibacho, Takatsuki City, Osaka Prefecture No. 51-17 (72) Inventor Yoshihiro Saruwatari No. 402, B15 Bldg.1, Otoyama Yumoka, Yawata City, Kyoto Prefecture (72) Inventor Tatsuya Yagyu 4-3 Ouricho, Neyagawa City, Osaka (56) References JP Hei 8-92494 (JP, A) JP-A-57-36693 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20 CA (STN) REGISTRY ( STN)

Claims (10)

(57) [Claims] 1. An ink composition comprising a dye represented by the following general formula (I). Embedded image [Wherein, M represents H, an alkali metal, optionally substituted ammonium, morpholinium, or piperidinium, and R ¹ represents H, NH ₂ , or COOM (where M is as defined above) , R ² is COOM or -P, (= O) n- ( OM)
₂ (where M is as defined above and n represents 0 or 1); R ³ is H or SO ₃ M (where M is as defined above); R ⁴ And R ⁵ are each independently H, having 1 to 6 carbon atoms.
Represents an alkyl group or an alkoxyl group having 1 to 6 carbon atoms; R ⁶ represents H, an optionally substituted phenyl group, an alkylcarbonyl group, or an alkyl group optionally substituted by a hydroxyl group or an alkoxyl group; m represents 0 or 1. ] 2. The composition according to claim 1, further comprising a nonionic acetylene glycol-based surfactant, and a glycol ether.
The ink composition according to claim 1. 3. The ink composition according to claim 1, further comprising a polyhydric alcohol. 4. The ink composition according to claim 1, further comprising a nitrogen-containing cyclic compound. 5. A dye represented by the formula (I):
The ink composition according to claim 4, comprising 1% to 30% by weight of a polyhydric alcohol, and 1% to 30% by weight of a nitrogen-containing cyclic compound. 6. A composition comprising 2 to 8% by weight of the dye represented by the formula (I), 3 to 20% by weight of a polyhydric alcohol, and 3 to 20% by weight of a nitrogen-containing cyclic compound. 6. The ink composition according to 5. 7. The method according to claim 1, wherein M comprises a dye represented by the general formula (I) representing at least one of ammonium, morpholinium and piperidinium which may be substituted. The ink composition as described in the above. 8. The ratio of M, which is an alkali metal salt, to the number of M in the entire dye represented by formula (I) is 50.
%. The ink composition according to claim 7, wherein the content is not more than 10%. 9. An ink jet recording method, comprising a step of discharging the ink composition according to any one of claims 1 to 8 through a fine hole as a droplet to perform recording on a recording medium. 10. A recorded matter recorded by the method according to claim 9.