JP2002069350A - Ink jet ink, ink cartridge, recording unit, ink jet recording method using the same, ink jet recording apparatus, and method of stabilizing ink ejection characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet ink, an ink cartridge, and a recording which can stably exhibit good ejection characteristics and obtain high-quality images at a low cost when ink collected after idle ejection or the like is reused. Provided are a unit, an inkjet recording method, an inkjet recording apparatus, and a method for stabilizing ink ejection characteristics. SOLUTION: At least (A) diethylene glycol,
(B) at least one of trimethylolpropane and ethylene urea, (C) a glycol whose vapor pressure at 20 ° C. is lower than diethylene glycol, (D) a coloring material, (E) water, (A)
To (E), and the total amount of the components of the three groups (A), (B) and (C) is 10 to 4 with respect to the total amount of the ink.
Inkjet ink within the range of 0% by mass, an ink cartridge using the ink, a recording unit, an inkjet recording method, and a recording apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet ink, an ink cartridge, a recording unit, an ink jet recording method, an ink jet recording apparatus, and a method for stabilizing ink ejection characteristics.

[0002]

2. Description of the Related Art In an ink jet recording method, recording is performed by flying small ink droplets and attaching the ink to a recording material such as paper. In particular, JP-B-61-59911, JP-B-61-59912 and JP-B-61-59912.
According to the ink jet recording method disclosed in Japanese Patent No. 59914, which uses an electrothermal converter as an ink ejection energy supply unit and generates droplets by applying thermal energy to the ink to generate bubbles.
It is possible to easily realize the on-demand recording and the high-density multi-orifice of the recording head, and to record a high-resolution and high-quality image at a high speed.

However, in such an ink jet recording method, since the inside of a nozzle of a recording head for discharging ink communicates with the outside air, the ink in the nozzle may be dried or foreign matter or bubbles may enter from the outside air. May cause nozzle clogging. On the other hand, idle discharge operation for discharging ink from all nozzles of the recording head toward the ink receiving member (cap), capping the nozzle surface of the recording head, and applying a negative pressure to the nozzle surface by suction means such as a pump. 2. Description of the Related Art An ejection recovery operation for forcibly ejecting ink from a nozzle by means such as spraying and eliminating clogging of the nozzle is performed. At this time, especially in the case of a long recording head in which a large number of nozzles are arranged, a large amount of ink is ejected irrespective of the recording operation by the above-described idle ejection or ejection recovery operation. However, there is a problem that the consumption of the device increases and the running cost of the device increases. Therefore, an ink jet recording apparatus having a structure capable of recycling a large amount of ink ejected by idle ejection or ejection recovery operation has been developed.

However, a large amount of ink ejected during a physical operation for preventing nozzle clogging, such as the above-described idle ejection or ejection recovery operation, is exposed to the outside air, and thus is subject to evaporation due to moisture and the like. In some cases, the ink composition or ink characteristics may change, and if this is collected and used again for recording, the resulting image quality may be impaired.

In particular, in an on-demand type ink jet recording apparatus, ink is not always discharged from all the nozzles, but is discharged from the nozzles only when necessary for image formation. In many cases, there is a state in which no ink flows.
If the state in which there is no ink flow in the nozzle for a long time, specifically, for example, the time in which the ink in the nozzle faces the recording medium in a state where the ink is not subjected to the ejection recovery operation exceeds 5 seconds When such a situation occurs, the coloring material may be fixed particularly at the head end portion due to evaporation of moisture and the like from the nozzle end portion, and the nozzle may be clogged due to the evaporation, and smooth recording may be performed. May not be done. As a countermeasure against such a phenomenon, as described above, the idle ejection and the ejection recovery operation are performed. The ink used for the idle ejection and the ejection recovery operation is collected and reused (recycled) for image formation. In such a case, as described above, since the ink composition or the ink characteristics may have already changed due to evaporation of moisture or the like, this phenomenon may be particularly remarkable. Further, when evaporation of moisture or the like from the nozzle tip occurs, the viscosity of the ink at the tip of the head tends to increase, and the start-up characteristics may deteriorate.

Further, it is known that the above-described deterioration of the start-up characteristics may be more serious in an ink jet printer of a type that prints an image or the like with a print head fixed. Have been obtained by the present inventors. That is, in the case of an ink jet printer that records an image or the like by scanning the recording head, the ejection recovery operation can be performed frequently during the recording operation. It is possible to suppress the continuation of time. However, it is difficult for an ink jet printer of a type in which the recording head is fixed during recording to perform the ejection recovery operation of the recording head during the recording operation. Is likely to occur. When the present inventors attempt to recycle the ink used for the ejection recovery operation in such a printer, the change in the composition of the ink collected and reused, and the ink jet ejection characteristics due to the change in the composition. Has come to the realization that countermeasures against changes in technology are a more important technical issue.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for recovering water or a solvent contained in ink even when the recovered ink is reused after being used for the above-described idle discharge or discharge recovery operation. Provided is an ink-jet ink stably exhibiting good ejection characteristics, in which the ink composition hardly changes because evaporation hardly occurs, and the ink ejection characteristics are not easily changed even when the ink composition changes. It is in. Another object of the present invention is to provide an ink jet recording method capable of obtaining a high quality recorded matter at a reasonable cost. Another object of the present invention is to provide an ink jet recording apparatus capable of stably forming high-quality recorded matter at a reasonable cost, and an ink cartridge and a recording unit which can be used for the apparatus. It is a further object of the present invention to provide a method for stabilizing the ink ejection characteristics of an ink jet printer having a recycling mechanism for collecting and reusing ink for image formation.

[0008]

The ink jet ink according to one embodiment of the present invention, which can achieve the above object, comprises at least (A) diethylene glycol, (B) trimethylolpropane, and ethylene urea. On the other hand, (C) a glycol whose vapor pressure at 20 ° C. is lower than diethylene glycol, (D) a coloring material,
(E) Water contains five groups of components (A) to (E), and the total amount of the three groups of components (A), (B) and (C) is based on the total amount of the ink. In the range of 10 to 40% by mass.

[0009] An ink cartridge according to one embodiment of the present invention is characterized in that the ink cartridge includes an ink storage section that stores ink-jet ink having the above composition.

[0010] The recording unit according to one embodiment of the present invention includes, for example, an ink storage section for storing ink-jet ink having the above composition, and a head section for discharging the ink. It is characterized by.

The ink jet recording method according to one embodiment of the present invention is characterized in that at least one of (A) diethylene glycol, (B) trimethylolpropane and ethylene urea, and (C) the vapor pressure at 20 ° C. is lower than that of diethylene glycol. Low-glycol, (D) colorant, (E) water, containing five components of (A) to (E), and three components of (A), (B) and (C) Using an ink whose total amount is in the range of 10 to 40% by mass with respect to the total amount of the ink, giving energy to the ink,
A step of discharging ink from the orifice toward the recording surface in an on-demand manner.

An ink jet recording apparatus according to one embodiment of the present invention is, for example, a recording head for ejecting an ink jet ink having the above-described composition, and an ink cartridge having an ink storage section for storing the ink. And an ink supply unit for supplying the ink from the ink cartridge to the recording head.

An ink jet recording apparatus according to another embodiment of the present invention has, for example, an ink storage section for storing an ink jet ink having the above composition, and a head section for discharging the ink. Characterized in that it comprises a recording unit.

An ink jet recording apparatus according to another embodiment of the present invention has at least one of (A) diethylene glycol, (B) trimethylolpropane and ethylene urea, and (C) a vapor pressure at 20 ° C. which is lower than that of diethylene glycol. Low-glycol, (D) colorant, (E) water, containing five components of (A) to (E), and three components of (A), (B) and (C) An ink containing section containing an inkjet ink whose total amount is within a range of 10 to 40% by mass with respect to the total amount of the ink, a recording head for ejecting the ink, and a recording head ejected from the recording head. Means for collecting the ink stored in the ink storage section.

An ink jet recording apparatus according to still another embodiment of the present invention comprises: (A) at least one of diethylene glycol, (B) trimethylolpropane, and ethylene urea; and (C) a vapor pressure of diethylene glycol at 20 ° C. Lower glycols,
(D) a colorant, (E) water, containing five groups of components (A) to (E), and a total amount of three groups of (A), (B) and (C) , 10 to 40% by mass based on the total amount of ink
An ink container containing an inkjet ink within a range of: a recording head for discharging the ink; an ink receiving member for receiving the ink discharged from the recording head; It is characterized by comprising an ink flow path connecting the ink container and a pump for collecting the ink received by the ink receiving member into the ink container.

An ink jet recording method according to another embodiment of the present invention is an ink jet recording method using the above ink jet recording apparatus, wherein at least one ink jet recording method is used.
The cycle includes a recycling step of ejecting ink including ink jet recording ink that has been ejected and collected from the recording head.

According to still another aspect of the present invention, there is provided an ink jet recording method, wherein an ink containing an ink jet ink which has been ejected from a recording head at least once and is collected is ejected from the recording head again. In the ink-jet recording method having the formula (I), the ink-jet ink comprises at least (A)
Diethylene glycol, (B) at least one of trimethylolpropane and ethylene urea, (C) glycol having a lower vapor pressure at 20 ° C. than diethylene glycol, (D) coloring material, (E) water, (A) to (E). It is characterized by containing five groups of components, and the total amount of the three groups of components (A), (B) and (C) is in the range of 10 to 40% by mass with respect to the total amount of the ink. And

A method for stabilizing ink ejection characteristics in an ink jet printer according to one embodiment of the present invention is as follows.
A method for stabilizing ink ejection characteristics in an ink jet recording method having a recycle step of ejecting an ink containing an ink jet ink that has been ejected and recovered from a recording head at least once from the recording head, the method comprising: As at least,
(A) diethylene glycol, (B) at least one of trimethylolpropane and ethylene urea, (C) 20
A glycol having a vapor pressure at 0 ° C. lower than diethylene glycol, (D) a coloring material, (E) water, containing five components of (A) to (E), and (A), (B) and ( C)
The total amount of the components of the three groups is 10 to 4 with respect to the total amount of the ink.
It is characterized by using an ink for inkjet which is 0% by mass.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to preferred embodiments. The ink-jet ink according to the present invention is a water-based ink, and at least one of (A) diethylene glycol, (B) trimethylolpropane, and ethylene urea as essential components of the ink.
(C) a glycol having a vapor pressure at 20 ° C. lower than that of diethylene glycol, (D) a coloring material, (E) containing five components of water, and selected from three components of (A), (B) and (C). The component is contained in an amount of 10 to 40% by mass, preferably 15 to 30% by mass based on the total amount of the ink. The present inventors have made it possible to effectively suppress the evaporation of water and solvent in the ink by using the above-described structure of the inkjet ink. For example, even when the ink is exposed to the outside air, A change in the composition is suppressed, and even when the ink composition changes due to evaporation of water, etc., the change in the ejection characteristics of the ink is unlikely to occur, so the ink is collected and reused for image formation. Also, the present invention has been made based on the knowledge that good ejection characteristics can be stably obtained.

More preferred embodiments of the ink-jet ink according to the present invention further include (A), (B) and (C)
Each of the three groups of components is used in an amount of 1 to 20 with respect to the total amount of ink.
%, More preferably 2 to 1% by mass.
What contained in the range of 8 mass%, More preferably, 3 to
One contained in the range of 15% by mass is exemplified. These three groups of components are mixed, for example, within the above-mentioned amounts, respectively, and the total amount of the three groups of components (A), (B) and (C) is 10% of the total ink amount. ~ 40% by mass
With such a configuration, it is possible to more effectively suppress the evaporation of water in the ejection path and the recycling path in the ink jet recording apparatus. Even when exposed to the conditions, not only the evaporation of the water but also the evaporation of the solvent component can be suppressed, so that the effect of making the precipitation of the coloring material difficult to occur and the effect of suppressing the increase in the viscosity of the ink can be obtained.

As a result, the ink that has been discharged from the recording head at least once and that has passed through the recycling path also exhibits substantially the same ink discharge characteristics as ordinary ink. Further, clogging and an increase in viscosity due to the deposition of the coloring material can be suppressed, so that the start-up characteristics and sticking resistance of the ink are also improved. Therefore, the ink of the present invention is particularly effective for an on-demand type ink jet recording apparatus and a recycle type ink jet recording apparatus in which a part of ink is collected after passing through a nozzle and the collected ink is used again for recording. Available to

Hereinafter, each component of the ink of the present invention will be described. Among the components constituting the ink according to the present invention, examples of the components included in the group (C) include glycols having a vapor pressure lower than that of diethylene glycol at 20 ° C., for example, triethylene glycol, tetraethylene glycol, and weight. Examples include polyethylene glycol having an average molecular weight of about 400.

As examples of the coloring materials of the group (D), dyes and pigments conventionally used in ink jet inks can be used without any problem. Examples of dyes include, for example,
Examples include reactive dyes, acid dyes, direct dyes, basic dyes, and disperse dyes. Among these, it is preferable to use a reactive dye, an acid dye, and a dye represented by the following formula (I). In order to maintain a high image density and an appropriate ink viscosity, the content of these coloring materials in the ink is preferably 0.1 to 15% by mass relative to the total amount of the ink, and 0.1 to 10% by mass. More preferably, it is mass%.

[0024]

When a disperse dye or pigment is used as the coloring material of the ink, it is usually necessary to disperse the dispersant using a dispersant or the like. However, it is preferable to use a self-dispersion pigment as the pigment, since the amount of the dispersant added can be reduced or the dispersant need not be added, so that the effects of the present invention become more remarkable.

In order to dissolve or disperse the coloring materials of the group (D) as described above into ink, the water of the liquid (E) is used as a liquid medium. The content of water in the ink is 10 to 95% by mass, preferably 25 to 9% by mass, based on the total amount of the ink.
The content is desirably 3% by mass, more preferably 40 to 90% by mass. As the water used in the present invention, ion exchange water is preferably used.

In the ink according to the present invention, in addition to the above-mentioned water as a liquid medium, the following water-soluble organic solvents can be further used in combination, whereby the effect of the present invention is more remarkable. It can be something. As the water-soluble organic solvent used at this time, specifically, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol Alkyl alcohols having 1 to 5 carbon atoms such as n-pentanol; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; dipropylene Oxyethylene or oxypropylene addition polymers such as glycol; alkylene glycols such as ethylene glycol, propylene glycol, trimethylene glycol; glycerin, trimethylolethane, 1,2 Triols such as 6-hexanetriol; bishydroxyethyl sulfone; lower alkyls such as ethylene glycol monomethyl (or ethyl, butyl) ether, diethylene glycol monomethyl (or ethyl, butyl) ether, and triethylene glycol monomethyl (or ethyl, butyl) ether Glycol ethers; lower dialkyl glycol ethers such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; monoethanolamine, diethanolamine,
Alkanolamines such as triethanolamine; and sulfolane, N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. Among these, water-soluble organic solvents such as ethylene glycol, glycerin, 1,2,6-hexanetriol, ethyl alcohol, isopropyl alcohol, and bishydroxyethyl sulfone are particularly preferable.

In the ink according to the present invention, when an acid dye or a dye represented by the above formula (I) is used as a coloring material, a change in physical properties of the ink or an ink flowing member due to the peroxide of diethylene glycol. This may have an effect, but in this case, it can be suppressed by adding a buffer to the ink. For example, in this case, it is preferable to add lithium acetate as a buffer to suppress the pH to a weakly alkaline region.

Furthermore, in the ink according to the present invention, in addition to the above components, if necessary, a viscosity modifier, a preservative, an antioxidant, an antirust agent, a rust preventive, and the like for giving desired performance to the ink. Additives such as a mold agent and a chelating agent may be blended.

(Inkjet Recording Apparatus) As components constituting the inkjet recording apparatus, first,
FIGS. 1, 2 and 3 show examples of the configuration of a head which is a main part of an apparatus utilizing thermal energy. FIG. 1 is a cross-sectional view of the head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG. The head 13 is made of glass, ceramic,
It is obtained by bonding a heating element substrate 15 to a silicon or plastic plate or the like. The heating element substrate 15 includes a protective layer 16 formed of silicon oxide, silicon nitride, silicon carbide, and the like, and electrodes 17-1, 17-2, Hf formed of aluminum, gold, an aluminum-copper alloy, or the like.
Heat generating resistor layer 18 formed of a high melting point material such as B ₂ , TaN, and TaAl, heat storage layer 19 formed of thermally oxidized silicon, aluminum oxide, and the like, and good heat dissipation properties such as silicon, aluminum, and aluminum nitride It consists of a substrate 20 made of a material.

The electrodes 17-1 and 17- of the head 13
When a pulse-like electric signal is applied to the area 2, the area indicated by n of the heating element substrate 15 rapidly generates heat, bubbles are generated in the ink in contact with the surface, and the meniscus 23 is generated by the generated pressure. The ink protrudes from the nozzle 1 of the head 13
The ink is discharged through the discharge orifice 22 and becomes an ink droplet 24 from the discharge orifice 22, and flies toward the recording material 25.

FIG. 3 is an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head is formed by bonding a glass plate 27 having a multi-nozzle 26 and a heating head 28 similar to that described with reference to FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating this head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and forms a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head 65, and is held in a form protruding into the movement path of the recording head 65 in the example shown in FIG. Reference numeral 62 denotes a cap on the protruding opening surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, comes into contact with the ink ejection opening surface, and is capped. Is provided. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, and is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove moisture, dust, and the like from the ejection port surface.

Reference numeral 65 denotes a discharge energy generating means,
A recording head 66 for performing recording by discharging ink onto a recording material facing a discharge port surface provided with discharge ports, and 66 is a recording head 6
5 is a carriage on which the printhead 65 is mounted to move the recording head 65. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown).
As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area. Reference numeral 51 denotes a paper feed unit for inserting a recording material, and reference numeral 52 denotes a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the discharge port surface of the recording head 65, and as the recording proceeds, the discharge rollers 5
The sheet is discharged to the sheet discharge section where the number 3 is arranged.

In the above arrangement, when the recording head 65 finishes recording and returns to the home position, the ejection recovery section 64
Is retracted from the moving path of the recording head 65, while the blade 61 protrudes into the moving path.
As a result, the ejection openings of the recording head 65 are wiped. When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement path of the recording head. When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as the position at the time of the wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement.

The above-described movement of the print head to the home position is performed not only at the end of printing or at the time of ejection recovery, but also at a predetermined interval while the print head moves through the printing area for printing. Position, and the wiping is performed along with the movement.

FIG. 5 is a diagram showing an example of an ink cartridge 45 containing ink supplied to a recording head via an ink supply member (not shown), for example, a tube. Here, reference numeral 40 denotes an ink storage section 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 can be supplied to the head. An ink absorber 44 receives the waste ink. It is preferable that the ink container has a surface in contact with the ink made of polyolefin, particularly polyethylene.

As described above, the ink jet recording apparatus according to the present invention is not limited to the one in which the head and the ink cartridge are separated from each other, but also the one in which they are integrated as shown in FIG. It is preferably used. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink container containing ink, for example, an ink absorber is stored, and the ink in the ink absorber is transferred from a head unit 71 having a plurality of orifices. It is configured to be ejected as ink droplets. It is preferable to use a polyurethane or polyolefin-based material as the material of the ink absorber.

Further, a structure may be employed in which the ink container is an ink bag in which a spring or the like is provided inside without using an ink absorber. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The recording unit 70 is used in place of the recording head 65 of the recording apparatus shown in FIG. 4, and is detachable from the carriage 66.

When carrying out the ink jet recording method according to the present invention, for example, an ink jet printer in which the recording head shown in FIG. 3 is mounted on the carriage of the ink jet printer is used. FIG. 7 is a schematic perspective view showing one example. In FIG. 7, reference numeral 81 denotes a recording head for discharging ink. Ink is ejected from the recording head toward a recording material in accordance with a recording signal.

FIG. 8 is a side sectional view showing the internal structure of a color printing apparatus for performing printing in accordance with an ink jet printing system which is a typical embodiment of the present invention. In such an apparatus, a fixed and long full-line recording head having a recording width corresponding to the width of a recording material is provided as a recording head. This recording apparatus is particularly suitable for high-speed recording of a color image on a recording material such as a label.

In FIG. 8, the recording apparatus 101 feeds a roll paper 200, which is a recording material, into a recording apparatus by a roll paper conveying roller 206 when the recording operation is performed. Belt 2
04, the roll paper 200 is transported in the direction of the arrow.
The recording apparatus ejects black (K), cyan (C), magenta (M), and yellow (Y) inks.
Full-line recording heads 201K, 201C, 201
A head unit 202 containing M and 201Y is provided, and a color image is formed on a roll paper 200 using ink supplied from four ink cartridges 205 containing inks of Y, M, C, and K colors. Record.

FIG. 9 shows that the ink-jet printer apparatus of the present invention having the above-mentioned fixed recording head has a structure in which a part of the ink is collected after passing through the nozzle, and the collected ink is reused. It shows an example of a recycling system in the case where a recycling system used for recording is provided. In such a recycling system, the recording head 300
However, the recovery process and the preliminary ejection are performed in the state of being close to the ink receiving member 302, and the ink ejected from the recording head 300 is collected by the ink receiving member 302. The collected ink is returned to the sub ink tank 308 by a recycle pump 312 disposed between the ink receiving member 302 and the sub ink tank 308.

Here, the recycle pump 312 is connected to one end of the ink supply path 310, two suction ports connected to one end of the supply path 306 from the main tank 304, and to one end of the ink supply path 314. Discharge port portion. The recycle pump 312 is activated at a predetermined timing by a control unit (not shown). Further, the recording head 3 is provided in the sub ink tank 308.
00 and an ink supply path 318 connected to the
16 are connected.

The ink used for the recovery processing and the preliminary ejection is supplied to the sub-ink tank 308 by the recycling system described above.
The collected ink is mixed with the ink in the main ink tank 304 and can be reused.
After the ink collected in the ink receiving member 302 is once returned to the main tank 304, the main tank 3
The ink is supplied to the sub ink tank 308 together with the ink of No. 04 and may be reused.

[0046]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. <Examples 1 to 8 and Comparative Examples 1 to 5> After mixing and stirring each ink component according to the composition shown in Table 1 below, the mixture was filtered through a Fluoropore filter to obtain Examples 1 to 8 and Comparative Example 1 of the present invention. To 5 inks.

[0047]

Each of the inks obtained in Examples 1 to 8 and Comparative Examples 1 to 5 was filled into a 200 ml-filled ink tank of a color bubble jet card printer (trade name: P-400CII, manufactured by Canon Inc.). To form an image. The card printer shown in FIG.
And a long recording head is fixed as shown in FIG. 9, and the ink ejected from the head by an operation such as a pressure recovery operation or a preliminary ejection is collected and returned to the ink tank. A recycling path for reusing the ink for forming an image with the used ink is provided. In this printer, about 3.6 ml of each ink is ejected by one pressure recovery operation. An image was formed under the following conditions, and the following items were evaluated from the obtained image.

[Evaluation Items] (1) Start-up Characteristics In a 25 ° C., 10% humidity environment, the printer was turned off.
After leaving it for 2 hours in the F state, and further leaving it for 2 hours under normal temperature and normal humidity (25 ° C., humidity 60%), the power was turned on and the initial printing state was confirmed. The evaluation criteria are as follows. Table 2 shows the evaluation results. A: There is no difference from the print state before leaving. B: Although there is a slight difference from the printing state before leaving, there is no problem in printing. C: Clearly different from the print state before leaving.

(2) Sticking resistance Color bubble jet card printer P-400CI
Remove the recording head of I from the main body, 35 ° C, humidity 10%
After being left in the environment for 2 weeks, the printer was mounted again, and it was checked whether or not printing could be recovered by a normal recovery operation. The evaluation criteria are as follows. Table 2 shows the evaluation results. A: It recovers by one main body recovery operation. B: Recovered by several body recovery operations. C: Not recovered by the main body recovery operation.

(3) Discharge Stability in Recycling Use of Ink Color bubble jet card printer P-400CI
Using I, the character pattern was continuously printed until the ink in the cartridge was almost used up, and the character quality was visually evaluated. Until the printing was completed, the pressure recovery operation was performed a total of 30 times (3.6 × 30 = 108 ml). The evaluation criteria are as follows. Table 2 shows the evaluation results. A: There is no difference in character quality near the beginning and end of use of the cartridge. B: There is a slight difference in character quality near the beginning and end of use of the cartridge. C: There is a difference in character quality near the beginning and end of use of the cartridge.

[0052]

Further, when the inks of Examples 1 to 8 are used, recording of substantially the same ink is performed between the normal ink and the recycle ink after passing through the recycle path after performing the pressure recovery operation 30 times. It was confirmed that the film exhibited characteristics. From the above results, the ink-jet ink according to the present invention has the same ejection characteristics as ordinary ink even when the ink is collected and reused, and also has good start-up properties and adhesion resistance. It was confirmed that this was an excellent inkjet ink that could be suitably used for various inkjet recording apparatuses.

[0054]

As described above, according to the present invention,
Compared to conventional inks, even in the case of a device that has excellent start-up properties and anti-sticking properties, and has a recycling mechanism that collects ink and reuses it for image formation, ink characteristics are unlikely to change, and good ejection characteristics The present invention provides an inkjet ink, an ink cartridge, a recording unit, an inkjet recording method using these, and an inkjet recording apparatus capable of performing inkjet recording stably.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a head of an ink jet recording apparatus.

FIG. 2 is a sectional view taken along line AB in FIG.

FIG. 3 is a schematic explanatory diagram of a multi-head.

FIG. 4 is a schematic perspective view showing one embodiment of an ink jet recording apparatus.

FIG. 5 is a longitudinal sectional view showing one embodiment of an ink cartridge.

FIG. 6 is a perspective view illustrating an example of a recording unit.

FIG. 7 is a schematic perspective view when the recording head is mounted on a carriage of an inkjet printer.

FIG. 8 is a side sectional view showing the internal structure of an embodiment of the ink jet recording apparatus.

FIG. 9 is a schematic view of an example of a recycling system of an inkjet printer having a method of recycling collected ink.

[Explanation of symbols]

13: Head 14: Nozzle 15: Heating Element Substrate 16: Protective Layer 17-1, 17-2: Electrode 18: Heating Resistor Layer 19: Heat Storage Layer 20: Substrate 21: Ink 22: Discharge Orifice 23: Meniscus 24: Ink Small droplet 25: recording material 26: multi-nozzle 27: glass plate 40: ink bag 42: stopper 44: ink absorber 45: ink cartridge 51: paper feed unit 52: paper feed roller 53: paper discharge roller 61: blade 62 : Cap 63: Ink absorber 64: Ejection recovery unit 65: Recording head 66: Carriage 67: Guide shaft 68: Motor 69: Belt 70: Recording unit 71: Head part 101: Color recording device 200: Roll paper 201K, 201C, 201M, 201Y: full line recording head 202: head unit 203: transport Roller 204: Conveying belt 205: Ink cartridge 206: Roll paper conveying roller 300: Recording head 302: Ink receiving member 304: Main tank 306, 310, 314, 318: Ink supply path 308: Sub ink tank 312: Recycle pump 316: Return passage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA14 EA19 EA25 FA03 FA10 FC02 HA05 JC23 KB16 KC14 2H086 BA01 BA02 BA53 BA56 BA62 4J039 BA29 BC07 BC09 BC36 BC37 BC40 BC51 BC54 BC65 BC73 BC79 BE01 BE03 BE04 BE05 BE41 CA03 CA06 EA42 EA44 GA24

Claims (22)

[Claims] 1. (A) diethylene glycol, (B) at least one of trimethylolpropane and ethylene urea, (C) glycol having a vapor pressure at 20 ° C. lower than diethylene glycol, (D) a colorant,
(E) Water contains five groups of components (A) to (E), and the total amount of the three groups of components (A), (B) and (C) is based on the total amount of the ink. Characterized in that the content is in the range of 10 to 40% by mass. 2. The ink jet ink according to claim 1, wherein the component (D) is a dye. 3. The ink according to claim 1, wherein the component (A) is contained in an amount of 1 to 20% by mass based on the total amount of the ink.
3. The ink for inkjet according to item 1. 4. The ink according to claim 1, wherein the component belonging to the group (B) is contained in an amount of 1 to 20% by mass based on the total amount of the ink.
Or the inkjet ink according to 2. 5. The ink according to claim 1, wherein the component belonging to the group (C) is contained in an amount of 1 to 20% by mass based on the total amount of the ink.
5. The ink-jet ink according to any one of items 4 to 4. 6. The recording apparatus according to claim 1, wherein a part of the ink is collected after passing through the nozzle, and the collected ink is used in a recording apparatus of a system that is used again for image formation. Ink for inkjet. 7. The ink-jet ink according to claim 1, which is used in a recording apparatus in which the time in which the ink in the nozzle faces the recording surface is continuously 5 seconds or more. . 8. The ink-jet ink according to claim 1, which is used in a recording apparatus that performs printing while the head is fixed without moving. 9. An ink cartridge, comprising: an ink storage unit that stores the inkjet ink according to claim 1. Description: 10. An ink container for accommodating the inkjet ink according to claim 1, and a head for ejecting the ink. The recording unit to do. 11. The recording unit according to claim 10, further comprising a recording head configured to discharge the ink from an orifice by applying thermal energy to the ink to the head unit. 12. At least one of (A) diethylene glycol, (B) at least one of trimethylolpropane and ethylene urea, (C) a glycol having a vapor pressure lower than diethylene glycol at 20 ° C., (D) a coloring material,
(E) Water contains five groups of components (A) to (E), and the total amount of the three groups of components (A), (B) and (C) is based on the total amount of the ink. An ink jet recording method comprising the steps of using an ink within a range of 10 to 40% by mass, applying energy to the ink, and discharging the ink from the orifice toward the recording surface in an on-demand manner. 13. The ink jet recording method according to claim 12, wherein the energy is heat energy. 14. A recording head for discharging the inkjet ink according to claim 1,
An ink jet recording apparatus, comprising: an ink cartridge having an ink storage section for storing the ink; and an ink supply section for supplying the ink from the ink cartridge to a recording head. 15. The ink jet recording apparatus according to claim 14, wherein the recording head is a head that ejects the ink by applying thermal energy to the ink. 16. A recording unit, comprising: an ink container for storing the ink for ink jet recording according to claim 1; and a head for discharging the ink. An ink jet recording apparatus, comprising: 17. The ink jet recording apparatus according to claim 16, wherein the recording head is a head that ejects the ink by applying thermal energy to the ink. 18. An ink container containing the ink-jet ink according to claim 1, a recording head for discharging the ink, and an ink discharged from the recording head. And a means for collecting the ink in the ink storage unit. 19. An ink containing section for containing the ink for ink jet recording according to claim 1, a recording head for discharging the ink, and an ink discharged from the recording head. An ink receiving member for receiving the ink, an ink flow path connecting the ink receiving member to the ink containing portion, and a pump for collecting the ink received by the ink receiving member to the ink containing portion. An ink jet recording apparatus comprising: 20. An ink jet recording method using the ink jet recording apparatus according to claim 18 or 19, wherein the ink including the ink for ink jet recording which has been ejected and collected at least once from a recording head is ejected. An ink jet recording method comprising a recycle step. 21. An ink jet recording method comprising an ink recycling step of discharging ink containing ink jet ink that has been ejected and collected at least once from a recording head again from the recording head.
The ink-jet ink according to any one of claims 1 to 8,
13. An ink-jet recording method, which is the ink-jet ink described in item 9. 22. A method for stabilizing ink discharge characteristics in an ink jet recording method comprising a recycle step of discharging ink containing ink jet ink that has been discharged and collected at least once from a recording head from the recording head. At least (A) diethylene glycol, (B)
At least one of trimethylolpropane and ethylene urea, (C) a glycol having a lower vapor pressure at 20 ° C. than diethylene glycol, (D) a coloring material, and (E) water.
(A) containing five groups of components (A) to (E), and (A)
A method for stabilizing ink ejection characteristics, comprising using an inkjet ink in which the total amount of the three groups of components (B) and (C) is 10 to 40% by mass based on the total amount of the ink.