JP3976509B2 - Yellow ink composition for inkjet recording - Google Patents

Description

【００３８】
表１から、実施例のインク組成物は、優れた耐目詰まり性を有し、連続印刷を行っても安定した吐出が可能で、保存安定性にも優れていることがわかる。一方、比較例のインク組成物は、保存安定性の点で良好なものもあるが、ノズル内で目詰まりを起こし、連続印刷が行えないことがわかる。これらの結果から、本発明のインク組成物は、構成成分のいずれか１種類でも欠けると本発明の優れた効果が得られないことがわかる。
【００３９】
【発明の効果】
本発明によれば、耐目詰まり性に優れ、連続印刷を行っても安定した吐出が可能で、かつ長期の保存安定性に優れたインク組成物を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water-based yellow ink composition for ink-jet recording that is suitably used for ink-jet recording in which ink is ejected and ejected by mechanical energy and / or thermal energy and recording is performed on a recording material.
[0002]
[Prior art]
The ink jet recording method is a method of recording an image by forming ink droplets using a mechanical and / or thermal action, and depositing the ink droplets on a recording material such as paper to form dots. This ink-jet recording method does not include processes such as development and fixing required for recording methods such as electrophotography, so that the apparatus can be easily downsized and at the same time can be recorded at high speed and with low noise. is there. In addition, such an on-demand recording method has a simple recording apparatus and can be easily made full-color, and its application research is expected to be actively performed in the future.
[0003]
As ink characteristics desired for the ink jet recording method, not only recording characteristics such as print quality but also long-term reliability of the apparatus is important for clogging resistance of ink in the nozzle. The clogging of the ink is caused not only by the physical properties of the organic solvent used for the ink but also by the precipitation of the dye due to the change in various physical properties of the ink left for a long period of time. Thus, long-term storage stability is also strongly desired as ink characteristics.
[0004]
Conventionally, polyhydric alcohols have been used as ink wetting agents in order to improve the ink clogging resistance. Since the polyhydric alcohol itself has a low vapor pressure, and most of it is mixed with water in all proportions and is hygroscopic, it can suppress the evaporation of water in the ink and prevent the dye from being deposited.
However, the ink to which polyhydric alcohol is added tends to cause aggregation of dye molecules, and causes a phenomenon in which the aggregated and aggregated dye adheres to the nozzle and causes clogging before the dye is deposited due to evaporation of water in the ink.
[0005]
In order to solve such problems, an ink having improved clogging resistance by using N-methyl-2-pyrrolidone and glycerin as an organic solvent has been proposed (see Japanese Patent Publication No. 63-57475). . However, the long-term storage stability of the ink itself is insufficient.
[0006]
JP-B-6-78495 discloses a specific anionic dye and a water resistance imparting agent comprising a specific poorly water-soluble compound having a solubility of 5% by weight or more at 20 ° C. when dissolved in ethyl alcohol. A water-resistant ink composition as an active ingredient is disclosed. In this ink composition, the dye is micellized with a water resistance imparting agent and dissolved in water to improve the stability over time. However, this ink composition has a problem that ink followability is insufficient when continuous printing is performed.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a yellow ink composition that is excellent in clogging resistance, can be stably ejected even after continuous printing, and has excellent long-term storage stability.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors are excellent in clogging resistance and continuous by blending a specific water-soluble yellow dye and a water-soluble organic solvent in a specific ratio. It was found that a yellow ink composition capable of stable ejection even after printing, that is, good ink followability and excellent long-term storage stability was obtained, and the present invention was completed.
[0009]
Thus, according to the present invention, a water-soluble yellow dye 0.1 to 9 wt%, 4-51 wt% of water-soluble organic solvents and surfactants 0.01 to 5 wt% was contained at least, Ri Ah balance water Water-soluble organic solvent is 1 to 20% by weight of methyl carbitol, 1 to 5% by weight of diethylene glycol, 1 to 5% by weight of 1,3- dimethyl- 2- imidazolidinone, 1 to 20% by weight of ethylene urea, triethanol At least selected from CI Direct Yellow 86, CI Direct Yellow 107, CI Direct Yellow 132, CI Direct Yellow 142, CI Acid Yellow 17 and CI Acid Yellow 23. inkjet recording yellow ink composition comprising 1 Tanedea Rukoto (hereinafter, referred to as "ink composition" There is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the water-soluble yellow dye used in the present invention include known water-soluble yellow dyes, among which CI Direct Yellow 86, CI Direct Yellow 107, CI Direct Yellow 132, CI Direct Yellow 142, CI Acid Yellow 17 and CI Acid At least one selected from yellow 23 is preferred.
[0011]
The content of the water-soluble yellow dye in the ink composition of the present invention is 0.1 to 9% by weight, preferably 0.1 to 6% by weight, more preferably 0.3 to 5% by weight. When the content of the water-soluble yellow dye is less than 0.1% by weight, the required color tone and contrast are difficult to obtain, which is not preferable. Further, when the content of the water-soluble yellow dye exceeds 9% by weight, clogging is likely to occur in the nozzle, which is not preferable.
[0012]
The total content of the water-soluble organic solvent in the ink composition of the present invention is 4 to 51% by weight, preferably 10 to 50% by weight. If the total content of the water-soluble organic solvent is within the above range, ink ejection stability can be ensured. Moreover, when there is too much total content of the water-soluble organic solvent, since it may become a dry defect, it is unpreferable.
[0013]
Commercially available components can be used for each component of the water-soluble organic solvent used in the present invention, and the content of each component in the ink composition is as follows.
The content of methyl carbitol (diethylene glycol monomethyl ether) is preferably 1 to 20% by weight, more preferably 5 to 20% by weight, and even more preferably 5 to 15% by weight.
The content of diethylene glycol is preferably 1 to 5% by weight.
The content of 1,3-dimethyl-2-imidazolidinone is preferably 1 to 5% by weight.
The content of ethylene urea is preferably 1 to 20% by weight, more preferably 1 to 15% by weight, and still more preferably 5 to 10% by weight.
The content of triethanolamine is preferably 0.01 to 1% by weight.
[0014]
The surfactant to be blended in the ink composition of the present invention may be any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.
[0015]
Anionic surfactants include higher fatty acid salts, alkyl sulfates, alkyl ether sulfates, alkyl ester sulfates, alkyl aryl ether sulfates, alkyl sulfonates, sulfosuccinates, alkyl allyl and alkyl naphthalene sulfonates, alkyls. Examples thereof include phosphates, polyoxyethylene alkyl ether phosphates, and alkylaryl ether phosphates.
[0016]
Examples of the cationic surfactant include alkylamine salts, dialkylamine salts, tetraalkylammonium salts, benzalkonium salts, alkylpyridinium salts, imidazolinium salts, and the like.
[0017]
Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, glycerin ester polyoxyethylene ether, sorbitan ester poly Examples thereof include oxyethylene ether, polyoxyethylene ether of sorbitol ester, fatty acid alkanolamide, polyoxyethylene fatty acid amide, amine oxide, and polyoxyethylene alkylamine.
[0018]
Examples of amphoteric surfactants include dimethylalkyl lauryl betaine, alkyl glycine, alkyl di (aminoethyl) glycine, and imidazolinium betaine.
Among the above surfactants, for example, nonionic surfactants such as Union Carbide, trade name: Tergitol 15-S-15, Air Products, trade name: Surfynol 465 are preferably used.
[0019]
In the ink composition of the present invention, an additive may be blended as necessary in order to obtain a recording liquid having desired physical properties. Examples of such additives include antifoaming agents, nozzle drying inhibitors, fungicides, antiseptics, and rust inhibitors.
[0020]
Examples of the antifoaming agent include ethyl alcohol and isopropyl alcohol.
Examples of the nozzle drying inhibitor include urea, thiourea, ethylene urea, and derivatives thereof.
[0021]
Examples of fungicides, antiseptics and rust inhibitors include benzoic acid, dichlorophene, hexachlorophene, sorbic acid, p-hydroxybenzoic acid ester, ethylenediaminetetraacetic acid (EDTA), sodium dehydroacetate, 1,2-bezothiazoline. -3-one, 3,4-isothiazoline-3-one, and the like.
[0022]
In the ink composition of the present invention, for example, a water-soluble yellow dye is added to ion-exchanged water, stirred at room temperature to completely dissolve the water-soluble yellow dye, and then a water-soluble organic solvent is sequentially added. It is obtained by adding a surfactant, stirring at room temperature, and then filtering with a filter of a desired size.
[0023]
Various physical properties of the ink composition of the present invention can be appropriately controlled. According to a preferred embodiment of the present invention, the viscosity (25 ° C.) of the ink composition is 25 mPa · sec or less, preferably 10 mPa · sec or less. It is. If the viscosity of the ink composition is within the above range, ink ejection stability can be ensured. The surface tension (25 ° C.) of the ink composition is preferably 20 to 50 mN / m.
[0024]
【Example】
The present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to these examples.
[0025]
Example 1
An ink composition was prepared according to the following formulation.
A water-soluble yellow dye is added to ion-exchanged water and stirred at room temperature to completely dissolve the water-soluble yellow dye. Then, a water-soluble organic solvent is sequentially added, and finally a surfactant is added. After stirring for a period of time, the mixture was filtered through a 0.45 μm filter to obtain an ink composition.
[0026]
CI Acid Yellow 23 3% by weight
Methyl carbitol 8% by weight
Diethylene glycol 5% by weight
1,3-dimethyl-2-imidazolidinone 5% by weight
8% by weight of ethylene urea
Triethanolamine 0.5% by weight
Surfactant 0.5% by weight
(Union Carbide, product name: Tergitol 15-S-15)
The remaining ion exchange water 【0027】
(Example 2)
An ink composition was prepared in the same manner as in Example 1 except that the following formulation was used.
CI Direct Yellow 86 3% by weight
Methyl carbitol 10% by weight
Diethylene glycol 3% by weight
1,3-dimethyl-2-imidazolidinone 3% by weight
10% ethylene urea
Triethanolamine 0.5% by weight
1% by weight of surfactant
(Product name: Surfynol 465, manufactured by Air Products)
The remaining ion exchange water 【0028】
(Comparative Example 1)
An ink composition was prepared in the same manner as in Example 1 except that ethylene urea was not added.
CI Acid Yellow 23 3% by weight
Methyl carbitol 8% by weight
Diethylene glycol 5% by weight
1,3-dimethyl-2-imidazolidinone 5% by weight
Triethanolamine 0.5% by weight
Surfactant 0.5% by weight
(Union Carbide, product name: Tergitol 15-S-15)
The remaining ion exchange water 【0029】
(Comparative Example 2)
An ink composition was prepared in the same manner as in Example 1 except that 1,3-dimethyl-2-imidazolidinone was replaced with diethylene glycol.
CI Acid Yellow 23 3% by weight
Methyl carbitol 8% by weight
Diethylene glycol 10% by weight
8% by weight of ethylene urea
Triethanolamine 0.5% by weight
Surfactant 0.5% by weight
(Union Carbide, product name: Tergitol 15-S-15)
The balance of ion-exchanged water 【0030】
(Comparative Example 3)
An ink composition was prepared in the same manner as in Example 2 except that methyl carbitol was replaced with butyl carbitol.
CI Direct Yellow 86 3% by weight
Butyl carbitol 10% by weight
Diethylene glycol 3% by weight
1,3-dimethyl-2-imidazolidinone 3% by weight
10% ethylene urea
Triethanolamine 0.5% by weight
1% by weight of surfactant
(Product name: Surfynol 465, manufactured by Air Products)
The balance of ion-exchanged water [0031]
(Comparative Example 4)
An ink composition was prepared in the same manner as in Example 2 except that triethanolamine was not added.
CI Direct Yellow 86 3% by weight
Methyl carbitol 10% by weight
Diethylene glycol 3% by weight
1,3-dimethyl-2-imidazolidinone 3% by weight
10% ethylene urea
1% by weight of surfactant
(Product name: Surfynol 465, manufactured by Air Products)
The balance of ion-exchanged water [0032]
(Experiment 1: Continuous printing test)
Using the modified ink jet printer (IO-730) manufactured by Sharp Corporation, the ink compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were continuously printed at a printing density of 15%. The number of printable sheets was examined. The number of printable sheets until the ink tank is filled with the ink composition and becomes empty is about 200 sheets.
[0033]
In this experiment, the ink composition was refilled when it became empty, and this operation was repeated until printing could not be performed. The number of sheets that could be printed up to that time was defined as the number of printable sheets. The case where the number of printable sheets exceeded 400 was indicated as ◯, and the case where it was less than that was indicated as x. The obtained results are shown in Table 1.
[0034]
(Experiment 2: Clogging test)
Each of the ink compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 4 was filled into an ink cartridge, and after printing 10 sheets, the ink cartridge was removed from the printer, and the cap was not used for 7 days at room temperature. I left it alone. After leaving, the ink cartridge was again attached to the printer, and the case where printing was possible was marked as ◯, and the case where printing was not possible was marked as x. The obtained results are shown in Table 1.
[0035]
(Experiment 3: Storage stability test)
The ink compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were put in glass containers and allowed to stand at 60 ° C. for 60 days, and then the physical properties (viscosity, surface tension, pH) of the ink composition were as follows. It measured by the method of. The obtained physical property values were compared with the initial physical property values measured in advance (immediately after preparation of the ink composition). The obtained results are shown in Table 1.
[0036]
Viscosity: Viscosity at 20 ° C. was measured (unit: mPa · sec) using a viscosity measuring machine (trade name: Viscomate VM-1A-L, manufactured by Yamaichi Electronics Co., Ltd.).
Surface tension: The surface tension at 20 ° C. was measured (unit: mN / m) using a surface tension measuring device (trade name: CBVP-A3, manufactured by Kyowa Interface Science Co., Ltd.).
pH: The pH at 20 was measured using a pH measuring machine (manufactured by Shindengen Electric Co., Ltd., pH BOY-P2).
[0037]
[Table 1]

[0038]
From Table 1, it can be seen that the ink compositions of the examples have excellent clogging resistance, can be stably ejected even after continuous printing, and are excellent in storage stability. On the other hand, some of the ink compositions of the comparative examples are good in terms of storage stability, but clogging occurs in the nozzles, indicating that continuous printing cannot be performed. From these results, it can be seen that the excellent effect of the present invention cannot be obtained if any one of the constituent components of the ink composition of the present invention is lacking.
[0039]
【The invention's effect】
According to the present invention, it is possible to provide an ink composition that is excellent in clogging resistance, capable of stable ejection even when continuous printing is performed, and excellent in long-term storage stability.

Claims (1)

Water-soluble yellow dye 0.1 to 9 wt%, 4-51 wt% of water-soluble organic solvents and surfactants 0.01 to 5 wt% was contained at least, Ri Ah balance water,
Water-soluble organic solvent is methyl carbitol 1-20% by weight, diethylene glycol 1-5% by weight, 1,3- dimethyl- 2- imidazolidinone 1-5% by weight, ethylene urea 1-20% by weight, triethanolamine 0.01 to 1% by weight,
Inkjet water-soluble yellow dye, characterized in at least one Tanedea Rukoto selected from CI Direct Yellow 86, CI Direct Yellow 107, CI Direct Yellow 132, CI Direct Yellow 142, CI Acid Yellow 17 and CI Acid Yellow 23 A yellow ink composition for recording.