JP2001234191A - Liquid composition, cleaning method of ink jet recording head, ink jet recording device, cartridge and method for regenerating ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid composition capable of easily cleaning and removing a scorch on a heater formed during a long-term use of an ink jet recording head or a contaminant formed in the production of an ink jet recording head, and to provide a method for cleaning an ink jet recording head using the same and a method for regenerating an ink jet recording head, thereby to improve the life of the recording head, and to provide an ink jet recording device capable of stably forming an image for a long period of time. SOLUTION: The liquid composition comprises at least one cleaning agent in an effective amount for cleaning a cleaning part of an ink jet recording head, where the cleaning agent comprises an organic acid, a salt of an organic acid, an organic acid ester and a salt of an organic acid ester. Also are provided a cleaning method of an ink jet recording head, an ink jet recording device, an ink cartridge, and a method for regenerating an ink jet recording head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid composition, a method for cleaning an ink jet recording head and an ink jet recording apparatus using the liquid composition, a cartridge filled with the liquid composition, and the liquid composition. The present invention relates to a method for reproducing an ink jet recording head.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed as ink jet recording methods. Among them, for example, an ink jet recording method (so-called bubble jet recording method) described in JP-A-54-51837 for ejecting ink as ink droplets by the action of thermal energy is known as a high-density multi-nozzle method. Is very simple, so that high-quality images can be obtained at high speed and at very low cost, and can be printed on plain paper without a special coat layer for receiving ink. ing.

In the above-described ink jet recording method, bubbles are generated in the liquid on the heater due to rapid heating of the heater on the recording head, causing a rapid increase in volume. Then, by the action force based on the sudden increase in volume, the ink droplets are ejected and fly from the nozzle at the tip of the recording head, adhere to the recording material, and recording is performed.

When a large amount of recording is performed by the above method, the heater on the recording head is repeatedly heated in order to discharge ink, and a decomposition product of ink, a so-called kogation, is deposited on the heater surface. Due to the accumulation of kogation, the thermal energy of the heater is not effectively transmitted to the ink, and the amount of ejected ink droplets and the speed of the ejected ink droplets are reduced compared to the initial stage, and the ink droplets cannot be ejected. May fall into As described above, in order to improve the ink droplet ejection life of the ink jet recording head, it is required to reduce the accumulation of kogation, and various ink compositions have been proposed to prevent the occurrence of kogation.

For example, JP-A-3-160070 proposes an ink containing oxo anions. As oxo anions, phosphates, polyphosphates, phosphates, arsenates, molybdates, sulfates, sulfites, oxalates are mentioned, but they are still insufficient and further There is a demand for a longer life of ink ejection characteristics of an ink jet recording head.

[0006] In addition, the heater surface of a fresh ink jet recording head may be contaminated by various processes, and the ink ejection characteristics may become unstable from the initial stage. On the other hand, in order to stabilize the initial ejection characteristics, it has been proposed to perform an aging process as described in, for example, JP-A-2-78554. However, when the aging process is performed, kogation may adhere to the heater surface, and the original ejection performance may not be exhibited, such as a decrease in the ejection amount of ink from the beginning. In order to solve the above problems, Japanese Patent Application Laid-Open No. 9-29985 proposes a method for cleaning an ink jet recording head using an aqueous solution containing an electrolyte.

[0007]

According to the study of the present inventors, the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 9-29985 can surely achieve the effect of cleaning the ink jet recording head. However, in this method, since cleaning is performed using a strong electrolyte aqueous solution containing inorganic ions, the heater is easily damaged, and it is necessary to pay close attention to handling. Then, from the viewpoint of further extending the life of the ink jet recording head, there is a lower possibility of damaging the heater, and the kogation generated on the heater surface of the ink jet recording head is more safely removed, or the heater surface is removed. He came to the realization that it was necessary to develop new technologies that could be cleaned.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a kogation on a heater which occurs when an ink jet recording head is used for a long time without affecting the ink jet recording head or while minimizing the effect on the ink jet recording head. Another object of the present invention is to provide a liquid composition capable of cleaning and removing contaminants during the manufacture of an inkjet recording head and extending the life of the inkjet recording head. It is another object of the present invention to provide a method of cleaning an ink jet recording head capable of removing kogation and dirt on the surface of the ink jet recording head while suppressing the influence on a heater of the recording head.
Another object of the present invention is to provide an ink jet recording apparatus capable of removing kogation and dirt on the surface of an ink jet recording head while suppressing the influence on a heater of the recording head, and a cartridge usable therefor. I do. Still another object of the present invention is to provide a method for reproducing an ink jet recording head by washing or removing kogation and contaminants attached on a heater of the ink jet recording head.

[0009]

The above objects can be achieved by the present invention described below. That is, the liquid composition according to one embodiment of the present invention is a liquid composition containing at least one kind of cleaning agent in an effective amount for cleaning the cleaning portion of the inkjet recording head, wherein the cleaning agent is
It is at least one selected from the group consisting of organic acids, salts of organic acids, organic acid esters and salts of organic acid esters. A liquid composition according to another embodiment of the present invention, which can achieve the above object, has a heater whose surface is coated with an outermost protective layer containing at least one of a metal and a metal oxide. A liquid composition used for removing deposits on an ink-jet recording head that discharges ink containing a color material by the action of the heater, the liquid composition comprising: The object is characterized in that an object is oxidized and decomposed by applying energy to the heater in a state where the heater and the liquid composition are in contact with each other.

In addition, the above object can be achieved.
A method for cleaning an ink jet recording head according to an embodiment of the present invention is characterized in that the above liquid composition is used in a method for cleaning a cleaning portion of an ink jet recording head. According to another aspect of the present invention, there is provided a method for cleaning an ink jet recording head which can achieve the above object, wherein the surface is coated with an outermost surface protective layer containing at least one of a metal and a metal oxide. A method for cleaning an ink jet recording head including a heater, wherein heat energy is applied to the heater while the liquid composition is in contact with the heater. I do.

Further, the above object can be achieved.
An ink jet recording apparatus according to one embodiment of the present invention is a liquid tank filled with the liquid composition, an ink tank filled with ink containing a coloring material,
An inkjet recording head for discharging the liquid composition and the ink filled in the tank, and a supply for supplying the liquid composition and the ink from each of the liquid tank and the ink tank to the inkjet recording head, respectively Means and a valve means for arbitrarily selecting the supply of the liquid composition and the ink to the ink jet recording head.

Further, the above object can be achieved.
A cartridge according to an embodiment of the present invention is a cartridge used for cleaning a cleaning portion of an inkjet recording head including a heater whose outermost surface is covered with a protective film containing at least one of a metal and a metal oxide. The cartridge is configured to be detachable from the ink jet recording head, and is filled with the liquid composition. According to another embodiment of the present invention, there is provided a method for reproducing an ink jet recording head, comprising: a heater having a surface coated with a top surface protective layer containing at least one of a metal and a metal oxide; And a method for reproducing an ink jet recording head for discharging ink containing a coloring material, wherein the heater surface is provided on the heater surface.
In a state where the liquid composition according to any one of
The heat energy is applied to the heater.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. First, as an effective cleaning agent for cleaning the ink jet recording head contained in the liquid composition according to the present invention, for example, a cleaning agent containing an organic acid can be mentioned. The reason why organic acids are effective for cleaning and removing kogation and contaminants generated on the heater surface is not clearly understood, but is considered as follows. That is, when the organic acids are foamed on the heater surface of the ink jet recording head, the burnt and contaminants adhered on the heater surface are oxidized and decomposed, or the burnt and contaminants are washed and removed by the impact of foaming and defoaming. To be
It is considered that the heater can be returned to the initial clean state again, and as a result, the ink ejection characteristics that have become unstable due to kogation or contaminants adhered on the heater surface can be stabilized again. .

In the above-mentioned Japanese Patent Application Laid-Open No. 9-29985, kogation is removed by using an aqueous solution containing a strong electrolyte and utilizing an electrochemical reaction on the heater surface.
The liquid composition containing the organic acids according to the present invention is slightly ionized and does not cause an electrochemical reaction on the heater surface.

In the liquid composition according to the present invention, the organic acids that can be used as a cleaning agent for the heater of the ink jet recording head include organic acids, salts of organic acids, organic acid esters, and salts of organic acid esters. No. And, these salts are preferably any of lithium salts, sodium salts and potassium salts. Examples of the organic acid include carboxylic acids, sulfonic acids, phenols, and the like. Among them, carboxylic acids or salts thereof are preferable, and carboxylic acids having a hydroxyl group or salts thereof are more preferable.

Examples of the carboxylic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid and benzoic acid; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid and fumaric acid. And dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; and polycarboxylic acids such as ethylenediaminetetraacetic acid.

The sulfonic acid includes, for example, ethanesulfonic acid. Examples of the phenols include phenol (carbonic acid), 4-phenolsulfonic acid, 1-naphthol, 2-naphthol, 1-naphthol-4-sulfonic acid, 2-naphthol-6-sulfonic acid and the like. Examples of the carboxylic acid having a hydroxyl group include lactic acid, malic acid, citric acid and the like.

The organic acid esters include, for example, polyol phosphate esters and the like. Polyol phosphates include polyols, monosaccharides, oligosaccharides,
And polysaccharide phosphates. Such substances include, for example, α-glycerophosphate, β-glycerophosphate, glucose-1-phosphate, glucose-6-phosphate, mannose-6-phosphate, galactose-6-phosphate, fructose-6. -Phosphoric acid, glucose-1,6-
Examples include diphosphate, fructose-1,6-diphosphate, ascorbate phosphate, sucrose phosphate, sorbitol phosphate, phosphorylated polyglycerin, and phosphorylated polyethylene glycol. Among them, α-glycerophosphate and β
Glycerophosphoric acid is preferred.

Particularly preferred organic acids for use in the liquid composition of the present invention include, for example, aldonic acid, γ
-Aldonolactone, δ-aldonolactone, aldonates, aldanic acids and aldanates. First, aldonic acid, γ-aldonolactone, δ-aldonolactone, and aldonates will be described. Aldonic acid is a polyoxycarboxylic acid corresponding to one obtained by oxidizing an aldehyde group of aldose to a carboxyl group,
It is represented by the general formula HOCH ₂ (C ^* HOH) _n COOH (where n represents an integer of 0 or more and C ^* represents an asymmetric carbon atom). As described above, aldonic acid has an asymmetric carbon atom represented by C ^* , and thus has many optical isomers.

5 or more carbon atoms (where n =
The aldonic acid (3 or more) rarely exists alone in an aqueous solution. Aldonic acid having 5 or more carbon atoms forms a lactone ring with a part of the γ-position or the δ-position hydroxyl group, and becomes γ-aldonolactone and δ-aldonolactone, respectively. It is said to exist as an equilibrium mixture of γ-aldonolactone and δ-aldonolactone. In addition, carbon number 4 (in the above general formula, n
The aldonic acid of = 2) is rarely present alone in an aqueous solution. Aldonic acid having 4 carbon atoms is partially γ
Form a lactone ring with the hydroxyl group at the
Aldonolactone, and is said to exist as an equilibrium mixture of aldonic acid and γ-aldonolactone.

Aldonic acid is classified by the number of carbon atoms, and has 4 carbon atoms.
(N = 2 in the above general formula) is tetronic acid; one having 5 carbon atoms (n = 3 in the above general formula) is pentonic acid; 6 carbon atoms (n = 2 in the above general formula)
4) is collectively called hexonic acid. Specific examples of the aldonic acid include, for example, glycolic acid having 2 carbon atoms (n = 0 in the general formula) (alias: hydroxyacetic acid); glyceric acid having 3 carbon atoms (n = 1 in the general formula); Erythronic acid, threonic acid having 4 carbon atoms (n = 2 in the above general formula); ribonic acid, arabonic acid, xylonic acid having 5 carbon atoms (n = 3 in the above general formula);
Lixonic acid; 6 carbon atoms (n = 4 in the above formula)
Gluconic acid, allonic acid, altronic acid, mannonic acid,
Gulonic acid, idonic acid, galactonic acid, and taronic acid; examples include glucoheptonic acid having 7 carbon atoms (n = 4 in the above general formula), and some of them include D-form, L-form and DL-form. .

Among the aldonic acids, particularly preferred is gluconic acid having 6 carbon atoms. Gluconic acid alone is rarely present in an aqueous solution. Normally, gluconic acid partially forms a lactone ring between the γ-position and the δ-position hydroxyl group, respectively, and becomes γ-gluconolactone or δ-gluconolactone, respectively.
It is said to exist as an equilibrium mixture of gluconolactone and δ-gluconolactone. Gluconic acid is
There are D-form, L-form and DL-form, any of which may be used, but generally D-gluconic acid of D-form can be easily obtained. Also, as optical isomers of gluconic acid, for example, allonic acid, altronic acid, mannonic acid, gulonic acid, idonic acid, galactonic acid, talonic acid and the like are present, since these show properties similar to gluconic acid, These may be used.

Examples of the gluconate include lithium gluconate, sodium gluconate, potassium gluconate, magnesium gluconate, calcium gluconate, barium gluconate, iron (II) gluconate, and copper (II) gluconate. And the like. Especially, it is preferable to use lithium gluconate, sodium gluconate, and potassium gluconate. These gluconic acids and salts thereof can be used alone or in combination of two or more.

Next, aldanic acid and aldanates will be described. Aldanic acid (also referred to as aldaric acid) is a polyoxydicarboxylic acid corresponding to one obtained by oxidizing an aldehyde group and a primary alcohol group of aldose together to form a carboxyl group, and having a general formula of HOCH ₂ (C ^* HOH) _n COOH (however, n represents an integer of 0 or more, and C ^* represents an asymmetric carbon atom). Aldanic acid has an asymmetric carbon atom represented by C ^* , and therefore has many optical isomers. Aldanic acid having 5 or more carbon atoms (n = 3 or more in the above general formula) forms mono- and dilactone rings by causing intramolecular dehydration, although there is a difference in difficulty. Monolactone is also referred to as lactone acid, and depending on the conditions, two kinds of monolactones are generated, one based on a carboxyl group and the other based on a carboxyl group.

Aldanic acid is classified by the number of carbon atoms and has 3 carbon atoms.
(In the above general formula, n = 1) are trialial acids;
Those having 4 carbon atoms (n = 2 in the above general formula) are tetralic acid; those having 5 carbon atoms (n = 3 in the above general formula) are pentalic acid (pentasaccharide acid); Those having the general formula of n = 4) are collectively referred to as hexalic acid (hexosaccharic acid). Specific examples of aldanic acid include, for example, three carbon atoms (n = 1 in the above general formula).
Tartronic acid; 4 carbon atoms (in the above general formula, n =
2) tartaric acid; 5 carbon atoms (in the above general formula, n =
3) Xylosaccharic acid, ribosaccharic acid, arabosaccharic acid; glucosugaric acid, mannosaccharic acid, idosaccharic acid, mucus acid, taro mucus acid, allo mucus having 6 carbon atoms (n = 4 in the above general formula) Examples include acids and the like, each of which has a D-form, an L-form, a meso-form and a DL-form.

Particularly preferred among the aldanic acids are:
It is tartaric acid. Tartaric acid has D-form, L-form, DL-form and meso-form, and any of them may be used. In general, L-form L-tartaric acid can be easily obtained. or,
Examples of the tartrate include lithium tartrate, sodium tartrate, potassium tartrate, magnesium tartrate, calcium tartrate, barium tartrate, iron (II) tartrate, copper (II) tartrate, and ammonium tartrate.
Among them, it is preferable to use lithium tartrate, sodium tartrate, potassium tartrate and sodium potassium tartrate. These tartaric acids or salts thereof can be used alone or in combination of two or more.

The content of the detergent as listed above in the liquid composition of the present invention is preferably from 0.05 to 40% by weight, more preferably from 0.3 to 40% by weight, based on the total amount of the liquid composition. The content is preferably in the range of 10% by weight. As the water to be contained in the liquid composition of the present invention, it is desirable to use deionized water instead of general water containing various ions. The content of water is preferably in the range of 60 to 99.95% by weight based on the total amount of the liquid composition.

The liquid composition of the present invention may contain a compound having an oxidizing power capable of oxidizing and decomposing the deposits on the recording head surface as described above, and water. A water-soluble organic solvent may be contained in order to adjust the viscosity and surface tension of the liquid composition to a suitable suitable viscosity and surface tension for use, or to stably foam the liquid composition.

Examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol,
C1-C5 saturated alcohols such as sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and n-pentanol; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol Kind;
Ethers such as tetrahydrofuran and dioxane; oxyethylene or oxypropylene (co) polymers such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol; Polyols having an alkylene group containing 2 to 6 carbon atoms, such as trimethylene glycol, triethylene glycol and 1,2,6-hexanetriol;
Glycerin; trimethylolethane and trimethylolpropane; lower alkyl ethers such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether and triethylene glycol monomethyl (or ethyl) ether; triethylene glycol dimethyl (or ethyl) ) Lower dialkyl ethers of polyhydric alcohols such as ether and tetraethylene glycol dimethyl (or ethyl) ether; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; sulfolane, N-methyl-2-pyrrolidone, 2- Examples include pyrrolidone and 1,3-dimethyl-2-imidazolidinone. The water-soluble organic solvents as described above can be used alone or as a mixture.

In order to stabilize the solubility of the detergent, a pH adjuster may be contained in the liquid composition. p
Specific examples of the H adjustor include hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and ammonium hydroxide; acids such as sulfuric acid and hydrochloric acid; lithium sulfate, sodium sulfate, potassium sulfate and ammonium sulfate. Carbonates such as lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium potassium carbonate, ammonium carbonate, ammonium hydrogen carbonate; lithium phosphate, monosodium phosphate, disodium phosphate And phosphates such as trisodium phosphate, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monoammonium phosphate, diammonium phosphate and triammonium phosphate.

Further, in addition to the above components, the liquid composition of the present invention may further contain, if necessary, various conventional additives known in the art, such as a viscosity modifier, a fungicide, a preservative, and an antioxidant. An anti-drying agent such as an agent, an antifoaming agent, a surfactant, and urea can be appropriately used in combination.

As the ink jet recording head to be cleaned with the liquid composition of the present invention described above, thermal energy corresponding to a recording signal is applied to ink in the chamber of the recording head, and ink energy is generated by the energy. The recording head is preferably used for an ink jet recording method (so-called bubble jet (registered trademark) recording method). A recording apparatus using such a recording method will be described below with reference to the drawings.

First, FIGS. 1 and 2 show an example of the configuration of a recording head which is a main part of an ink jet recording apparatus utilizing heat energy (so-called bubble jet recording apparatus). FIG. 1 is a cross-sectional view of the recording head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG. The recording head 13 has a flow path (nozzle) through which ink passes.
The heating element substrate 15 is obtained by bonding a glass, ceramic, silicon, polysulfone, plastic plate, or the like having 14 to the heating element substrate 15.

The heating element substrate 15 has a protective layer 16-made of silicon oxide, silicon nitride, silicon carbide, or the like.
1, a metal oxide such as a metal such as platinum or a platinum oxide;
More preferably, the outermost surface protective layer 16-2 formed of tantalum or an oxide of tantalum, and the electrodes 17-1 and 17-1 formed of aluminum, gold, an aluminum-copper alloy, or the like.
7-2, a heating resistor layer 18 formed of a high melting point material such as hafnium boride, tantalum nitride, tantalum aluminum, a heat storage layer 19 formed of silicon oxide, aluminum oxide, or the like; silicon, aluminum, aluminum nitride, or the like; It is composed of a substrate 20 formed of a material having good heat dissipation.

The electrodes 17-1 and 1 of the recording head 13
When a pulse-like electric signal is applied to 7-2, an area (heater) indicated by n of the heating element substrate 15 rapidly generates heat, and bubbles are generated in the ink 21 in contact with the surface thereof, The meniscus 23 protrudes by the pressure, and the ink 21 is ejected through the nozzle 14 of the recording head 13, becomes an ink droplet 24 from the ejection orifice 22, and flies toward the recording material 25. FIG. 3 shows an external view of an example of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head has a glass plate 27 having a multi-nozzle 26.
And a ripening head 28 similar to that described with reference to FIG.

Next, an ink jet recording apparatus according to the present invention will be described. The ink jet recording apparatus of the present invention is a liquid tank filled with the liquid composition of the present invention having the structure described above, an ink tank filled with ink containing a coloring material, and filled in these tanks. An ink jet recording head for discharging the liquid composition and the ink, a supply unit for supplying the liquid composition and the ink from each of the liquid tank and the ink tank to the ink jet recording head, and the ink jet recording apparatus. It is characterized by comprising a valve means for arbitrarily selecting the supply of the liquid composition and the ink to the recording head. FIG. 4 is a schematic view showing a supply path of the ink and the liquid composition in the ink jet recording apparatus of the present invention. As shown in FIG. 4, a switching valve is provided between ink tanks 126 containing ink containing color materials and a tank 127 containing the liquid composition according to the present invention, and supply means 126 ′ and 127 ′ connecting the recording head 13. 1
The switching valve 12 is configured to arbitrarily select an ink or a liquid composition and supply the ink or liquid composition to the recording head 13.

For normal printing, the ink is supplied from the ink tank 126 to the recording head 13 via the supply means 126 '. Then, for example, if the ink ejection becomes unstable due to the accumulation of kogation on the heater of the recording head 13 as a result of performing a large amount of printing and the ejection amount becomes small, the valve 12 is switched. Then, the liquid composition is supplied to the recording head 13 from the liquid composition tank 127 via the supply means 127 ′ to the recording head 13, and the heater of the recording head 13 is cleaned. Alternatively, even in the recording head 13 immediately after being manufactured, the heater may be contaminated in various manufacturing steps, and the ejection may be unstable. Also in this case, the liquid composition of the present invention is supplied to the recording head 13 in the same manner as described above,
Cleaning on the heater of the recording head 13 may be performed to stabilize the initial ejection.

As a method for cleaning the heater, a recording head is used.
From liquid 13, 1 × 10 ^Two~ 1 × 10⁷Departure, good
Preferably 1 × 10^Three~ 5 × 10⁶Just fire
No. After cleaning the heater, turn off the valve 12 again.
Instead, the ink is supplied to the recording head 1 via the supply means 126 '.
3 and printing is performed, and thereafter the ejection becomes unstable.
The cleaning on the heater may be performed by the above method every time.

Further, as a specific method of setting the time to perform cleaning on the heater, for example, the user is required to perform printing on a recording material such as recording paper at a predetermined number of times or at predetermined time intervals. A method for cleaning, a method for providing a dedicated switch and a sequence for removing the kogation on the printer body, and a method for having the user activate the drive for removing the kogation by the user, and a method for automatically printing the liquid composition cartridge by the printer body. And a method of driving the motor, which is configured so as to be able to be identified.

FIG. 5 is an external perspective view of an ink jet recording apparatus showing one embodiment of the present invention, FIG. 6 is a perspective view showing the internal structure of the ink jet recording apparatus of the embodiment shown in FIG. 5, and FIG. FIG. 8 is a perspective view of the configuration of the recording head carriage and the tube unit of the embodiment shown in FIG. 5, and FIG. 8 shows fitting of the tube members 126 ′ and 127 ′ for supplying the ink or liquid composition of the above embodiment and the switching valve member 12. FIG. 9 is a perspective view showing an example of the configuration of the joining portion, and FIG. 9 is an internal configuration diagram of the ink cartridge of the embodiment.

[0041] In FIG. 5, 1 is an ink jet recording apparatus (hereinafter, simply referred to as device), 2 denotes a main casing forming part of the device 1 of the case (hereinafter, simply referred to as case), the frame device 1 to be described later Both ends of the apparatus fixed to a part thereof, that is, parts except for a part corresponding to the width of the conveyance path through which the recording paper is conveyed, are all covered by the case 2.

A home position of the recording head is defined at one of both end portions of the apparatus fixed to a part of the frame, and when the recording is not performed, the recording head 1 at this position, An ejection recovery unit for capping the ink ejection port surface of the recording head at this position is covered by the main case 2. With the above-described configuration, during a daily operation, when a part of the case is opened and maintenance and inspection of the apparatus are performed, the recording head and the ejection recovery unit are inadvertently touched. Are effectively prevented from being displaced or being damaged.

Reference numeral 3 denotes a middle case which also forms a part of the case, and mainly covers a portion where the recording head 13 moves during recording. The middle case 3 is configured to be easily detached and attached, and a spur provided corresponding to a sheet discharge roller described later is attached to a part thereof. The spur is configured to be pressed against the paper discharge roller with an appropriate pressing force by mounting the middle case 3.

Reference numeral 4 denotes a paper feed cover which forms a part of the case and is provided to be freely opened and closed. The paper feeding lid 4 is provided so that both ends of the near side in the figure in the substantially rectangular shape are pivotally supported, and this is used as a rotation axis to be opened upward in the figure and held at a predetermined angle. Can be Then, with the paper feed cover 4 held at this angle, the paper feed cover 4 becomes substantially linear with a paper feed tray described later, and the recording paper can be placed thereon.

Reference numeral 6 denotes an ink lid which constitutes a part of a case provided on the front side of the apparatus. The ink lid 6 is rotatably supported by a shaft provided at a lower portion on the front side of the apparatus, and can be opened on the front side of the ink lid 6 as needed. This makes it possible to perform a detaching operation such as mounting and detaching the ink cartridge and the like housed therein.

Reference numeral 7 shown in FIG. 5 is a paper discharge tray which is detachably mounted on the apparatus 1 . The paper discharge tray 7 is mounted at a rear portion of the apparatus 1 with a predetermined angle, and is configured so that recording papers on which recording has been completed are sequentially stacked. An operation unit 8 is provided on one side of the main case 2 in front of the apparatus. The operation unit 8 includes a display unit 8b for displaying the instrumentation <br/> state of location 1 and the like, and a key 8a for inputting various commands to the device 1.

In FIG. 6, reference numeral 111 denotes a paper feed tray, which constitutes a paper feed unit together with the paper feed cover 4 shown in FIG. 5 being opened (not shown in FIG. 6). The paper feed tray 111 has a configuration in which recording paper is placed thereon, and the recording paper is conveyed in a direction indicated by an arrow Z by a paper feed roller (not shown). In this paper feed mechanism, 111
a is a guide plate for guiding paper feeding according to the size of the recording paper, and 111b is a groove for moving the guide plate 111a according to the size of the recording paper. The recording paper in the above description includes a plastic sheet or the like and broadly means a recording material.

Reference numeral 112 in FIG. 6 denotes a platen for regulating the recording surface of the recording paper. The platen is disposed downstream of the transport rollers on the recording paper transport path and opposed to a recording head 13 described later. Is done. Further, on the downstream side of the platen 112, a paper discharge roller 113 is provided, which is rotated by a motor (not shown) and cooperates with a spur held by the middle case 3 shown in FIG. The recording paper is discharged to the discharge tray 7 of No. 5.

Reference numeral 114 in FIG. 6 denotes a recording head unit, which includes four recording head chips corresponding to each ink color, which will be described in detail with reference to FIG. These head chips are mounted on the carriage main body 121 of the carriage section 120 so that they can be easily attached and detached. Reference numeral 122 denotes a carriage cover.
23 is a head cover. By attaching these covers to the carriage main body 121, electrical connection to the recording head chip and positioning and fixing of the chip are performed. Further, a sub-ink tank (not shown) can be provided in a part of the carriage main body 121. The sub-ink tank allows the sub-ink tank to collect air bubbles in the ink supply system and move the carriage into the ink supply system as the carriage moves. The generated pressure fluctuation is buffered so that the recording head 13 is not affected by bubbles or pressure fluctuation.

Reference numeral 124 denotes a cover fixed to the apparatus frame, which protects the ink supply tube unit 125 and a flexible cable (not shown) that follow the carriage 120 as it moves. 126Bk,
126C, 126M, and 126Y are ink cartridges mounted in the ink supply unit, and have ink colors of black (Bk), cyan (C), and magenta (M), respectively.
An ink bag for storing yellow and yellow (Y) ink and a waste ink bag for sucking ink discharged by ink suction or the like in the ejection recovery process are stored. Reference numeral 127a denotes a liquid composition cartridge (liquid composition tank) mounted in the ink supply unit, which sucks the liquid composition discharged from the bag for storing the liquid composition and the suction in the ejection recovery processing. Liquid composition bag for storing.

FIG. 7 shows a recording head chip provided for each of the four colors of ink, with the carriage cover 122 and the head cover 123 removed. When the recording head chip is mounted, a predetermined portion of the carriage main body 121 (for each color, 13
Bk, 13C, 13M, and 13Y) (shown as Bk, 13C, 13M, and 13Y), and electrical connection for transmitting a signal to the recording head 13 and supply of ink are performed.

In FIG. 7, reference numeral 131 denotes a recording head 13
A tube member (hereinafter simply referred to as a tube) 132 for supplying ink between the sub-tank and the sub-tank is a tube for supplying ink between the sub-tank and the ink cartridge. Polyethylene resin is suitable as the material of the tube, and it is preferable to form the tube as a thin-walled tube because the tube becomes translucent and the state of ink filling inside can be visually observed.

FIG. 8 is an external perspective view of a fitting portion between the tube member and the switching valve member of the above embodiment. As a method for switching between the ink and the liquid composition, a switching valve 12 is used. Examples of more suitable switching methods include:
Sub tank and print head 1 arranged in print head 13
It is desirable to arrange a valve mechanism between the third common liquid chamber.

The reason is considered as follows. That is, the sub-tank is generally designed to have an ink storage capacity of about 3 to 10 mL, while the common liquid chamber of the recording head has an ink storage capacity of about 0.3 to 0.5 mL. are doing. Therefore, when replacing the liquid composition including the sub-tank, the amount of wastefully discarded ink is considerably larger than when replacing the ink in the common liquid chamber. Therefore, supplying the liquid composition only to the liquid chamber of the recording head 13 and not supplying the liquid composition to the sub tank is advantageous in terms of the amount of ink discarded and the time required for discarding and refilling the ink. . As a specific method of arranging the valve mechanism between the sub-tank arranged in the recording head 13 and the common liquid chamber of the recording head 13, a method of providing a two-way valve between the sub-tank and the common liquid chamber, or an opening / closing valve And a check valve provided in combination.

In the method using a two-way valve as described above, a flow path through which ink flows is usually formed, and when a liquid composition is required, the valve is switched to supply the liquid composition to the recording head 13. One example is to form a flow path that is supplied only to the common liquid chamber. In this way, 2
Because of the directional valve, the liquid composition is not supplied to the sub-tank side, and the liquid composition does not mix with the ink in the sub-tank, so that there is no need to discard and replace the ink in the sub-tank.

As a method of using a check valve and an open / close valve, for example, there is a method in which a thin film made of polyethylene is thermally welded to an ink flow path while partially leaving an unwelded portion. In this case, the ink flows in one direction but does not flow in the opposite direction. Therefore, by connecting a pipe for supplying the liquid composition from the side of the normal flow path to the recording head liquid chamber side from the position where the check valve is disposed, and by arranging an open / close valve immediately beside this pipe, The liquid composition is supplied by opening and closing the valve.

As described above, when the liquid composition is supplied by opening the on-off valve at a pressure about 0.3 atm higher than the pressure at which the ink is normally supplied, the liquid composition is supplied to the check valve. Due to its existence, it does not flow to the sub tank side,
It flows to the liquid chamber side of the recording head 13. By this operation, the ink in the liquid chamber loses the pressure of the liquid composition and is pushed out of the recording head 13, and the common liquid chamber of the recording head 13 is replaced with the liquid composition. Next, when the supply of the predetermined liquid composition is completed, the open / close valve is shut off, and thereafter, a predetermined cleaning operation may be performed in this state. After that, the normal ink may be supplied and replaced by means such as suction recovery or pressurized supply.

FIG. 9 is an internal configuration diagram showing an example of an ink cartridge 126a containing ink supplied to the recording head 13 of the embodiment through a tube. Here, reference numeral 40 denotes an ink storage portion storing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 is
Can be supplied. An ink absorber 44 receives the waste ink. The ink container preferably has a liquid contact surface with ink formed of polyolefin, particularly polyethylene.

Further, it is preferable to add preliminary auxiliary means to the recording head 13 because the effect of the present invention can be further stabilized. If a specific auxiliary means is provided, it is effective to provide a capping means, a wiping means, and the like for the recording head 13 in order to perform stable recording.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of the recording material that can be recorded by the recording apparatus. As such a recording head, a configuration that satisfies the length by a combination of a plurality of recording heads, and a recording head that is integrally formed.
Any of the configurations as individual recording heads may be used.

The type and number of recording heads to be mounted are, for example, not only those provided for one color ink but also a plurality of inks having different recording colors and densities. May be provided in plurality. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, and may be either a print head integrally formed or a combination of a plurality of printing heads. The present invention is extremely effective for an apparatus provided with at least one of color and full color by color mixture.

As shown in FIG. 10, the ink jet recording apparatus of the present invention has an ink cartridge 126a and a recording head 13 which are detachable as necessary, as shown in FIG. 13 is attached to the ink supply port 133.
Through which the ink (not shown) in the ink cartridge is supplied to the recording head 13. In this way, the user can replace the ink cartridge or, if the ink still remains in the ink cartridge 126, if the print density is reduced or the image is disturbed due to kogation,
The liquid composition cartridge 127 a shown in FIG. 11 is mounted on the recording head 13, the liquid composition in the liquid composition cartridge 127 a is supplied to the recording head through the liquid composition supply port 134, and a discharging operation is performed on the recording head. By doing so, the kogation on the heater surface can be removed, or the heater surface can be cleaned.

At this time, the cartridge 126a containing the recording ink and the cartridge 1 containing the liquid composition
It is desirable to change the shape and size of each cartridge so that the cartridge 27a can be clearly distinguished from the cartridge 27a. Alternatively, it is also a preferable embodiment that the printer main body is provided with a mechanical shape or an electric contact for identifying that the liquid supplied to the recording head is a liquid composition. In a preferred embodiment, a small amount of a coloring material is added to the liquid composition so that the user can surely know whether or not ejection for removing kogation is being performed.

[0064]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, “parts” and “%” are based on weight unless otherwise specified. [Example 1
~ 6] The following components are mixed, sufficiently stirred and dissolved, and then pressure-filtered with a micro filter having a pore size of 0.2 µm (manufactured by Fuji Photo Film) to obtain liquid compositions of Examples 1 to 6. Each product (washing liquid) was prepared.

(Composition of the liquid composition of Example 1) 5 parts of sodium oxalate 10 parts of diethylene glycol 85 parts of water

(Composition of the liquid composition of Example 2) 5 parts of malic acid (DL form) 3 parts of sodium hydroxide 10 parts of diethylene glycol 82 parts of water

(Composition of the liquid composition of Example 3) Citric acid 5 parts Sodium hydroxide 3 parts Diethylene glycol 10 parts Water 82 parts

(Composition of the liquid composition of Example 4) ・ 10 parts of sodium gluconate ・ 10 parts of diethylene glycol ・ 80 parts of water

(Composition of the liquid composition of Example 5) Lithium tartrate (monohydrate) 10 parts Diethylene glycol 10 parts Water 80 parts

(Composition of the liquid composition of Example 6) ・ β-glycerophosphate disodium ・ pentahydrate 5 parts ・ diethylene glycol 10 parts ・ water 85 parts

[Comparative Example 1] The following components were mixed,
After sufficiently stirring and dissolving, the mixture was filtered under pressure through a micro filter having a pore size of 0.2 μm (manufactured by Fuji Photo Film) to prepare a liquid composition of Comparative Example 1. (Composition of the liquid composition of Comparative Example 1) Diethylene glycol 10 parts Water 90 parts

(Evaluation Ink A) The following components were mixed and sufficiently stirred to dissolve.
The resulting mixture was filtered under pressure with a micro filter (manufactured by Fuji Photo Film Co., Ltd.) to prepare Ink A for use in evaluating the liquid compositions of Examples 1 to 6 and Comparative Example 1.

[Evaluation] By using the liquid composition of Examples 1 to 6 and the liquid composition of Comparative Example 1 and the ink A, heat energy corresponding to a recording signal was applied to the ink. An ink-jet recording apparatus having an on-demand type multi-recording head (trade name: BC-02, manufactured by Canon Inc., the outermost protective layer on the heater is made of tantalum and an oxide of tantalum) that discharges the ink, has a drive pulse width of 1.1 μm ( On) +3.0 μs (Off) +3.2 μ
s (On), drive voltage 24.6V, drive frequency 6,25
Each liquid composition was evaluated under the condition of 0 Hz.

First, ink A is continuously ejected under the above-described apparatus and driving conditions, and ink droplets ejected from the recording head are continuously collected in a container every 1 × 10 ⁶ shots, and the amount is weighed by an electronic balance. did. And, 1 × 10 ⁶
The average amount of discharged droplets was calculated. In addition, continuous discharge
It went from the initial stage to 1 × 10 ⁸ shots. As a result, 9.9 ×
The average amount of ejected droplets between 10 ^{7 and} 1 × 10 ⁸ shots is about 70% of the average amount of ejected droplets after 1 × 10 ⁶ shots from the initial stage
It turned out that it became.

Further, the recording head used in the above-mentioned durability test was separated.
The nozzle heater surface used for discharge durability
Adhesion of kogation observed under a microscope (400x magnification)
Was seen a lot. 1 × 10⁸Departure
The liquid composition of the present invention is applied to the recording head after performing the ejection durability.
Was filled. And the nozzle used for the discharge durability
Using the liquid compositions of Examples 1 to 6 and Comparative Example 1
5 × 10 liquid composition ⁶Emitted and discharged. Then ink
Refill A, 1 × 10⁶Measure the average discharge volume
After that, the recording head was disassembled and the nozzle
Of the heater surface of the heater with an optical microscope (400x magnification)
did. The evaluation criteria are shown below. Table 1 shows the results.
You.

(1) Recovery of ejection amount A: The average ejection droplet amount after washing with each liquid composition is as follows:
90% compared to the average amount of ejected droplets from the initial to 1 × 10 ⁶ shots
I have recovered above. B: After washing with each liquid composition, the average amount of ejected droplets is
70% compared to the average volume of ejected droplets from initial to 1 × 10 ⁶ shots
９０90% or more and recovered slightly. C: After washing with each liquid composition, the average amount of ejected droplets is
70% compared to the average volume of ejected droplets from initial to 1 × 10 ⁶ shots
And did not recover at all.

(2) Amount of kogation A: Almost no kogation was observed. B: Slight adhesion of kogation is observed. C: Many kogation adheres.

[0078]

[0079]

As described above, according to the present invention,
Liquid composition capable of easily cleaning and removing kogation on heaters and contaminants during manufacturing of an ink jet recording head generated when the ink jet recording head is used for a long time, a method of cleaning an ink jet recording head using the same, and A method for reproducing an ink jet recording head is provided. As a result, an ink jet recording apparatus capable of improving the life of the ink jet recording head and capable of forming images stably for a long period of time is provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a recording head of an ink jet recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a recording head of the inkjet recording apparatus of the present invention.

FIG. 3 is an external perspective view of a multi-headed recording head shown in FIG. 1 of the present invention.

FIG. 4 is a schematic diagram showing paths of ink and a liquid composition in the ink jet recording apparatus of the present invention.

FIG. 5 is an external perspective view of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 6 is a perspective view of the internal configuration of the ink jet recording apparatus of the embodiment.

FIG. 7 is a configuration perspective view of a recording head carriage and a tube unit of the embodiment.

FIG. 8 is an external perspective view showing a fitted state of the tube member and the switching valve member of the embodiment.

FIG. 9 is a perspective view showing the internal configuration of an example of the ink cartridge according to the embodiment.

FIG. 10 is a configuration perspective view showing an example of a recording head and an ink cartridge of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 11 is a configuration perspective view showing an example of a recording head and a liquid composition cartridge of the ink jet recording apparatus according to one embodiment of the present invention.

[Explanation of symbols]

1: Inkjet recording device 2: Main case 3: Middle case 4: Paper feed cover 6: Ink cover 7: Discharge tray 8: Operation unit 8a: Key 8b: Display unit 12: Switching valve 13: Recording head 13Bk: Recording head Chip (black) 13C: print head chip (cyan) 13M: print head chip (magenta) 13Y: print head chip (yellow) 14: flow path (nozzle) 15: heating element substrate 16-1: protective film 16-2: Outermost protective layer 17-1, 17-2: Electrode 18: Heating resistor layer 19: Heat storage layer 20: Substrate 21: Ink 22: Discharge orifice (micropore) 23: Meniscus 24: Ink droplet 25 : Recording material 26: multi-nozzle 27: glass plate 28: heating head 40: ink bag 42: stopper 44: ink absorber 111: paper feed tray 11a: guide plate 111b: groove 112: platen 113: paper discharge roller 114: recording head unit 120: carriage unit 121: carriage body 122: carriage cover 123: head cover 124: cover 125: ink supply tube unit 126: ink tank 126 ' : Supply means 126 '126a: Ink cartridge 126Bk: Ink cartridge (black) 126C: Ink cartridge (Cyan) 126M: Ink cartridge (Magenta) 126Y: Ink cartridge (Yellow) 127, 127a: Liquid composition tank ( Liquid composition cartridge) 127 ': Supply means 127' 131: Tube member (between recording head and sub ink tank) 132: Tube member (Sub ink tank and ink cartridge) ) 133: ink supply port 134: liquid composition supply port

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C11D 17/08 B41J 3/04 101Z

Claims (27)

[Claims] 1. A liquid composition comprising an effective amount of at least one cleaning agent for cleaning a cleaning portion of an ink jet recording head, wherein the cleaning agent is an organic acid, a salt of an organic acid, or an organic acid ester. And a salt of an organic acid ester. 2. The liquid composition according to claim 1, wherein the ink jet recording head employs a method of ejecting ink droplets by applying thermal energy. 3. The liquid composition according to claim 2, wherein the cleaning portion of the ink jet recording head is an outermost surface protective layer on a heater of the ink jet recording head. 4. The liquid composition according to claim 3, wherein the outermost protective layer contains at least one of a metal and a metal oxide thereof. 5. The liquid composition according to claim 4, wherein the metal is tantalum. 6. The liquid composition according to claim 1, wherein the organic acid is a carboxylic acid. 7. The liquid composition according to claim 6, wherein the carboxylic acid is a carboxylic acid having a hydroxyl group. 8. The organic acid according to claim 1, wherein the organic acid comprises at least one selected from the group consisting of aldonic acid, γ-aldonolactone, δ-aldonolactone, and aldanoic acid.
6. The liquid composition according to any one of 5. 9. The liquid composition according to claim 1, wherein the salt of the organic acid contains at least one of an aldonate and an aldanate. 10. The liquid composition according to claim 1, wherein the organic acid ester is a polyol phosphate ester. 11. The liquid composition according to claim 1, wherein the salt of the organic acid ester is a salt of a polyol phosphate ester. 12. The liquid composition according to claim 1, wherein the salt is a lithium salt, a sodium salt, or a potassium salt. 13. The method according to claim 13, wherein the polyol phosphate ester is α
The liquid composition according to claim 10, wherein the liquid composition is glycerophosphate or β-glycerophosphate. 14. An ink jet printer comprising a heater whose surface is covered with an outermost surface protective layer containing at least one of a metal and a metal oxide, and ejecting an ink containing a coloring material by the function of the heater. A liquid composition used for removing deposits on a recording head surface generated in a recording head, wherein the liquid composition supplies energy to the heater in a state where the heater and the liquid composition are in contact with each other. A liquid composition, which oxidizes and decomposes deposits on the surface of an inkjet recording head when applied. 15. The liquid composition according to claim 14, wherein the liquid composition contains at least one selected from an organic acid, an organic acid ester, and a salt of an organic acid ester. 16. A method for cleaning a portion to be cleaned of an ink jet recording head, wherein the liquid composition according to claim 1 is used. 17. The method for cleaning an ink jet recording head according to claim 16, wherein said ink jet recording head has means for applying thermal energy to ink to eject ink droplets. 18. The method for cleaning an ink jet recording head according to claim 17, wherein the cleaning portion of the ink jet recording head is a top surface protective layer on a heater of the ink jet recording head. 19. The method according to claim 18, wherein the outermost surface protective layer contains at least one of a metal and a metal oxide. 20. The method according to claim 19, wherein the metal is tantalum. 21. A method for cleaning an ink jet recording head comprising a heater whose surface is covered with an outermost surface protective layer containing at least one of a metal and a metal oxide, according to claim 1, wherein 2. A method for cleaning an ink jet recording head, wherein a thermal energy is applied to the heater while the liquid composition according to claim 1 is in contact with the heater. 22. A liquid tank filled with the liquid composition according to any one of claims 1 to 15, an ink tank filled with ink containing a coloring material, and filled in the tank. An ink jet recording head for discharging the liquid composition and the ink, a supply unit for supplying the liquid composition and the ink from each of the liquid tank and the ink tank to the ink jet recording head, and the ink jet recording apparatus. An ink jet recording apparatus comprising a valve means for arbitrarily selecting the supply of a liquid composition and ink to a recording head. 23. An ink jet recording head for ejecting the ink, comprising a heater for ejecting ink droplets by applying thermal energy to the ink as means for ejecting the ink as ink droplets. 3. The ink jet recording apparatus according to claim 1. 24. The ink jet recording apparatus according to claim 23, wherein the heater has an outermost protective layer containing at least one of a metal and an oxide thereof. 25. The ink jet recording apparatus according to claim 24, wherein the metal is tantalum. 26. A cartridge used for cleaning a cleaning portion of an ink jet recording head provided with a heater whose outermost surface is covered with a protective film containing at least one of a metal and a metal oxide, wherein the cartridge comprises: It is configured to be detachable from the inkjet recording head,
A cartridge filled with the liquid composition according to any one of claims 1 to 15. 27. An ink jet recording apparatus comprising a heater whose surface is covered with an outermost surface protective layer containing at least one of a metal and a metal oxide, and for discharging an ink containing a coloring material. A head reproducing method, wherein heat energy is applied to the heater in a state where the liquid composition according to any one of claims 1 to 15 is in contact with the heater surface. A method for reproducing an ink jet recording head.