JP2000108493A - Filling liquid for ink jet recording head and method for preserving or transporting inkjet recording heat using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a precipitation of a dye or the like in the case of filling a dye ink composition or the like corresponding to a high quality level by blending a basic compound, a humectant, and water, and preparing a filling liquid for the head. SOLUTION: A basic compound, a humectant, and water are blended, and a filling liquid for an ink jet recording head is prepared. This filling liquid is filled in the head, and the head can be preserved or transported. As an embodiment of the compound, an inorganic basic compound of a water oxide of alkali metal, or an organic basic compound of a lower alkyl amine or the like is used. As an embodiment of the humectant, a water soluble polyhydric alcohol and the like, a formamide and the like, or an imidazole dinon and the like are used. A blending amount of the inorganic compound is 0.01 to 1 wt.%, a blending amount of the organic compound is 0.1 to 2 wt.% or a blending amount of the humectant is 1 to 80 wt.% to be suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filling liquid for an ink jet recording head and a method for storing or transporting the ink jet recording head using the same.

[0002]

2. Description of the Related Art When a newly manufactured ink jet recording head is sent from a manufacturer to a user or the like,
2. Description of the Related Art A head is transported in a state where a filling liquid is filled in an ink flow path. Conventionally, as this filling liquid,
Water containing a humectant (and optionally a surfactant) has been used.

[0003] However, recently, when a user or the like removes the filling liquid and then injects the ink composition to perform printing, a discharge failure sometimes occurs.

[0004]

When the present inventor searched for the cause, when a user or the like removed the filling liquid, a small amount of the filling liquid remained on the wall surface of the head or the like. It was found that the above-mentioned ejection failure occurred due to the presence of dye precipitates and pigment aggregates. The reason why dye precipitates or pigment aggregates are present in the filling liquid is that a manufacturer of the inkjet recording head performs a printing test before sending the head. That is, after manufacturing the head, a printing test is performed by inserting the ink composition into the head, and when injecting the filling liquid after removing the ink composition, a small amount of the ink composition adheres to the head wall surface or the like. And the remaining ink composition diffuses into the filling liquid. In addition, it has also been found that the reason why the above-described ejection failure has recently started to occur is due to a recent change in ink composition.

[0005] That is, since higher quality is required for ink compositions for ink jet recording, in the case of dye-based ink compositions, the dye concentration in the ink is increased or the ink is dissolved in water. Dyes with low properties have been used. Another factor is the recent increase in the number of ink compositions using pigments that are superior in various aspects to dyes. This is because the water-based pigment ink composition includes a dispersion of pigment particles, and thus easily causes aggregation.

Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks which have started to occur with recent changes in ink composition.

[0007]

According to the present invention, the above object can be attained by a filling liquid for an ink jet recording head, which comprises a basic compound, a humectant and water.

Another object of the present invention is to store or transport an ink-jet recording head in a state where the ink-jet recording head is filled with a filler liquid containing a basic compound, a humectant and water. The feature can also be solved by the above-mentioned method of storing or transporting the ink jet recording head.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The basic compounds which can be used in the filling liquid according to the invention can be inorganic or organic basic compounds. Examples of the inorganic basic compound include a hydroxide of an alkali metal (for example, sodium, potassium, or lithium), and sodium hydroxide and potassium hydroxide are preferable. Examples of the organic basic compound include mono-, di- or tri-lower alkylamine, mono-, di- or tri-lower alkanolamine, cyclic amine and diamine. Here, the carbon number of the lower alkyl moiety and the lower alkanol moiety is preferably 1 to 6, more preferably 1 to 4. Also, the lower alkyl and lower alkanol moieties of the di-substituted or tri-substituted can be the same or different, respectively.

The mono-, di- or tri-lower alkylamine includes, for example, mono-, di- or tri-
Methylamine, mono-, di- or tri-ethylamine, mono-, di- or tri-t-butylamine can be mentioned. Also, mono-, di- or tri-
Lower alkanolamines include, for example, mono-, di- or tri-methanolamine, mono-, di- or tri-ethanolamine. Examples of the cyclic amine include piperidine and pyrrolidine, and examples of the diamine include ethylenediamine and trimethylenediamine. As the organic basic compound, tri-ethanolamine, piperidine, or ethylenediamine is preferably used. The aforementioned inorganic or organic basic compounds can be used alone or in any combination.

The filling liquid according to the present invention can contain the above-mentioned basic compound in any amount within the scope of the present invention, but in the case of an inorganic basic compound, the filling liquid is based on the total weight of the filling liquid. , Preferably 0.01 to 1% by weight, more preferably 0.1 to 0.5% by weight. In the case of an organic basic compound, it is preferably 0.1 to 2% by weight, more preferably 0.3 to 1% by weight, based on the total weight of the filling liquid.
It is. If the concentration is too low, the present invention may not be able to sufficiently exhibit the intended effect.On the other hand, if the concentration is too high, the pH becomes too high, and there is a problem in safety. There is a problem that it becomes too high.

The filling liquid according to the present invention contains a humectant. As the humectant, the same humectant as the humectant used in the conventional filling liquid can be used. As the humectant, for example, water-soluble polyhydric alcohols, particularly,
Dihydric to pentahydric alcohols having 2 to 10 carbon atoms; nitrogen-containing hydrocarbon solvents, for example, formamides, imidazolidinones, pyrrolidones, or amines; and sulfur-containing hydrocarbon solvents. One or more humectants may be used in combination. Examples of the water-soluble polyhydric alcohol include dihydric to trihydric alcohols having 3 to 10 carbon atoms.
Polyhydric alcohols such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol,
Examples include dipropylene glycol, hexylene glycol, or 1,2,6-hexanetriol. One or more of the above humectants may be used in combination.

The filling liquid according to the present invention may contain the above-mentioned humectant in any amount within the scope of the present invention. Increasing the humectant content is effective in preventing the formation of pigment aggregates and preventing the precipitation of dyes.However, since the viscosity of the filling liquid increases, the filling and discharging properties of the head are inferior. Become. The content of the humectant can be appropriately selected in consideration of these advantages and disadvantages, and is generally preferably about 1 to 80% by weight, more preferably 1 to 50% by weight, based on the total weight of the filling liquid. It can be contained in a small amount.

The filling liquid according to the invention can optionally contain a surfactant. As a surfactant,
Any of anionic, cationic, amphoteric, and / or non-ionic can be used.

Examples of the anionic surfactant include, for example,
Alkyl sulfocarboxylate, α-olefin sulfonate, polyoxyethylene alkyl ether acetate, N
-Acyl amino acids and salts thereof, N-acylmethyl taurine salt, alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate, lauryl alcohol sulfate , Alkylphenol-type phosphate, alkyl-type phosphate, alkylarylsulfonate, diethylsulfosuccinate, diethylhexylsulfosuccinate, dioctylsulfosuccinate, and 2-vinylpyridine derivative, poly-4-vinylpyridine Derivatives and the like can be mentioned.

Examples of the amphoteric surfactant include betaine lauryldimethylaminoacetate, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut fatty acid amidopropyldimethylaminoacetate betaine, and polyoctylpolyaminoethyl. Glycine and other imidazoline derivatives can be exemplified.

Further, as the nonionic surfactant,
For example, polyoxyethylene nonyl phenyl ether,
Ethers such as polyoxyethylene dodecylphenyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and polyoxyalkylene alkyl ether;
Polyoxyethylene oleate, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquiolate, polyoxyethylene monooleate, polyoxyethylene stearate Ester-based surfactants, or acetylene glycol-based surfactants, for example,
2,4,7,9-tetramethyl-5-decyne-4,7-
Diol, 3,6-dimethyl-4-octyne-3,6-
Diols, 3,5-dimethyl-1-hexyn-3ol (for example, Nissin Chemical's Surfynol 104, 82, 4
65, 485, TG, etc.).

The filling liquid according to the invention can contain the surfactants in any amount within the scope of the present invention, but preferably not more than 10% by weight, based on the total weight of the filling liquid. Preferably, it can be contained in an amount of 0.1 to 5% by weight.

If necessary, a viscosity adjusting agent, a surface tension adjusting agent, a fungicide, and / or a preservative may be added to the filling liquid of the present invention.

The filling liquid of the present invention can be used for an ink jet recording head which has been subjected to preliminary experiments or printing using an arbitrary ink composition. In particular, an ink jet recording head using an aqueous pigment ink composition, or It is preferably applied to an ink jet recording head using a water-based dye ink composition having low water solubility.

When the filling liquid according to the present invention is used, pigment aggregation from the water-based pigment ink composition remaining on the ink flow path wall surface of the head after the preliminary experiment or after printing, and dye precipitation from the water-based dye ink composition are performed. Not only can be effectively suppressed or prevented, but also the additional effect of improving the moisturizing power of the filling liquid and improving the efficiency of cleaning the ink composition used in preliminary experiments and printing can be obtained.

Further, when the filling liquid according to the present invention is used, it is not necessary to use a special head cap or the like at the time of rotating the head, and it is not necessary to close a portion where the ink flow path communicates with the atmosphere. This is not only cost-effective, but also
For example, it is possible to prevent contamination or damage to the nozzle surface, which may occur when a user removes a head cap. Further, when ejection failure occurs due to precipitation of dyes and aggregation of pigments, it is necessary to wash an excess ink composition into the ink flow path in order to completely remove those precipitates and aggregations. On the other hand, when the filling liquid according to the present invention is used, it is not necessary to perform such a washing operation, so that wasteful consumption of the ink composition can be suppressed.

The filling liquid of the present invention can be easily prepared by mixing the above-mentioned components (with heating and / or stirring if necessary), and optionally filtering the mixture with a membrane filter or the like.

The method of storing or transporting the ink jet recording head according to the present invention can be carried out in the same manner as the conventional storing or transporting method, except that the above-mentioned filling liquid according to the present invention is used as the filling liquid. In particular, the present invention is preferably applied to an inkjet recording head using an aqueous pigment ink composition or an inkjet recording head using an aqueous dye ink composition having low water solubility.

[0025]

EXAMPLES The present invention will be described below in more detail with reference to examples, but these examples do not limit the scope of the present invention.

(Preparation Examples) Five kinds of filling liquids of the present invention (Examples 1 to 5) having the compositions shown in Table 1 and two kinds of conventional filling liquids (Comparative Examples 1 and 2) were prepared. Specifically, the respective components shown in Table 1 were mixed, and the mixture was heated and stirred at 40 ° C. for 1 hour.
The solution was filtered through a μm membrane filter to obtain a filling solution. The amounts of the components shown in Table 1 are% by weight.

(Evaluation of Physical Properties) A black pigment ink was filled in an ink jet head of an ink jet printer (MJ-8000C: manufactured by Seiko Epson Corporation). After continuously printing on A4 size paper (10 sheets) and confirming that the ink was filled, the ink was discharged from the head and further filled with the filling liquid shown in Table 1. Thereafter, the ink jet head was removed from the printer, and the head was left alone in a thermostat at 60 ° C. for one week.

One week later, the ink jet head was mounted on the printer and filled with ink in the initial filling mode. Each filling liquid was evaluated according to the following criterion depending on how many times cleaning was performed until all the nozzles were stably discharged. ：: Filling was possible only with the initial filling sequence. Δ: Cleaning was completed within two times. X: The dropout / flight bending was not recovered even after the cleaning was performed twice or more.

[0029]

[Table 1]

[0030]

According to the filling liquid for an ink jet recording head of the present invention, even when the ink is filled in an ink jet recording head using a dye-based ink composition or a water-based pigment ink composition corresponding to high quality, precipitation of the dye can be prevented. Aggregation of the pigment can be suppressed or prevented. Further, the moisturizing power is improved, and the cleaning efficiency for the ink composition is also improved.

In addition, there is no need to use a special head cap or the like at the time of transporting the head, and it is not necessary to close the portion where the ink flow path communicates with the atmosphere. Furthermore, there is no need to wash an excess ink composition by flowing it into the ink flow path in order to completely remove precipitates and aggregates that cause ejection failure.

Claims (4)

[Claims] 1. A filling liquid for an ink jet recording head, comprising a basic compound, a humectant and water. 2. The filling liquid for an ink jet recording head according to claim 1, further comprising a surfactant. 3. The ink-jet recording head according to claim 1, wherein the ink-jet recording head is stored or transported in a state where the ink-jet recording head is filled with an ink-jet recording head filling liquid containing a basic compound, a humectant and water. Storage or transportation method. 4. The method according to claim 3, wherein the ink-jet recording head filling liquid further contains a surfactant.