JPH09111166A - INK, INKJET RECORDING METHOD USING THE SAME, AND DEVICE USING THE INK - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To attain high image quality of print recording on various plain papers while maintaining high stability and reliability of ink, and to print with excellent water resistance. To provide an ink, an inkjet recording method, and a device using such an ink. SOLUTION: The entire ink has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C, and an initial component of the ink is at least a coloring material, water, and is dissolved or dispersed in water. And an ink jet recording method using the ink, and an apparatus using the ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink, an ink jet recording method using the ink, and an apparatus using the ink. More specifically, the present invention relates to acidic paper and neutral paper used in general offices. The present invention relates to an ink that provides a high-quality image when recorded by using the ink, has excellent stability and reliability of the ink, and has good water resistance, an inkjet recording method using the ink, and an apparatus using the ink.

[0002]

2. Description of the Related Art Writing instruments (fountain pens, felt-tip pens,
With respect to inks for water-based ballpoint pens and the like and inks for inkjet recording, various compositions have been reported. In particular, in recent years, there has been an increasing demand for higher image quality and improved water resistance of print recording on plain paper such as copy paper, report paper, notebooks, and notepapers used as recording paper in various fields. In order to meet these demands while maintaining high stability and reliability, detailed research and development have been conducted from various aspects such as ink composition and physical properties.

For example, in JP-A-63-289081, a molecular weight in ink is 10,000 to 500,000.
An ink containing the polycarboxylic acid type high molecular surfactant of No. 6 also contains, in JP-A-6-93224, a polycarboxylic acid containing a polycarboxylic acid ester and / or a salt thereof, and has a viscosity of 50 to 50. Ink of 2,000 cps has been proposed for improving the reliability of ballpoint pen inks.

However, in each of the above proposals, in a system for recording by the action of external energy such as a ballpoint pen, for example, the external energy is applied even if ink is stuck at the tip of the ballpoint pen (in this case, the external pressure is increased. However, in the ink jet recording system, recording is performed by applying internal energy (in this case, energy is applied to the internal ink from the ink ejection unit). In the unlikely event that the ink becomes stuck at the ejection port, it is difficult to increase the internal energy and sufficient reliability has not been obtained. Further, the water resistance of the recorded matter is insufficient.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention is to provide an ink, an ink jet recording method, and an apparatus using such an ink, for solving the above problems.

[0006]

The above object is achieved by the present invention described below. That is, according to the present invention, the entire ink has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C., and the initial component of the ink is at least a coloring material.
An ink characterized by comprising water and a liquid medium dissolved or dispersed in water, an inkjet recording method using the same, and a device using the ink.

According to the present invention, an ink in which clogging at the nozzle tip is significantly reduced even under adverse environmental conditions such as a high temperature environment, a low temperature environment, and a mixed environment of high temperature and low temperature, and an ink jet using the same A recording method and a device using such an ink are provided. The precise reason why the ink of the present invention can obtain high reliability against clogging in a bad environment such as a high temperature environment, a low temperature environment and a mixed environment of high temperature and low temperature is unknown, but the following: The reason is described in the range of speculation.

In general, a water-soluble ink using a solid color material is used at a concentration not higher than a saturation concentration of the color material with respect to the liquid medium of the water-soluble ink. When a large amount of water in the water-soluble ink evaporates, the concentration of the coloring material in the ink becomes equal to or higher than the saturation concentration, the coloring material is deposited, and when the water evaporation further proceeds,
The coloring material begins to harden. However, the ink of the present invention is
Even when the concentration of the coloring material in the ink is equal to or higher than the saturation concentration, the association of the coloring materials is suppressed, so that the coloring materials do not precipitate, and further,
Even if the water in the ink evaporates, the coloring material does not solidify, and it is presumed that high reliability against clogging can be obtained.

In the case of a recording system such as a ball-point pen which performs recording by directly contacting the recording material with the recording material, even if the ink is once clogged at the ejection port,
Although clogging can be removed by external energy due to friction with the recording material during recording, the inkjet recording method, which is a recording system that does not have such a function,
Usually, the water in the ink is evaporated from the ink ejection port, a large amount of the coloring material is deposited, and clogging occurs, which cannot be removed. However, even in such a case, when the ink of the present invention is used, since the coloring material in the ink does not associate with each other in the ejection port and inside the ejection port, deposition or clogging of the coloring material does not occur, that is, the ink Since it maintains a liquid state, it becomes possible to make the energy for the ink generated for ejecting the ink inside the ink ejection port function well, and the good ink ejection property, in other words, good recording property. It is presumed that it is possible to improve the anti-clogging property.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments. The ink of the present invention is characterized in that the entire ink has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C. Further, the ink of the present invention is characterized in that its initial components are at least a coloring material, water, and a liquid medium dissolved or dispersed in water.

It is preferable that the ink of the present invention does not generate a floating precipitate at the gas-liquid interface when the water content in the ink is evaporated at 60 ° C. The reason for this is that, for example, when the ink of the present invention is used in an ink jet recording method, the apparatus used in the method has a very small ejection port for ejecting the ink, and in order to improve the ink ejection, The area around the ejection port is covered with a water repellent, but if even a small amount of solid matter such as a coloring material is floating on the gas-liquid interface of the ink ejection port, this floating substance will cause the edge of the ejection port. On the other hand, which may deteriorate the ejection performance.

Further, the ink of the present invention has fluidity as a whole in a state where water in the ink is evaporated in an environment of 60 ° C., and the viscosity of the ink in that state is in the environment of 60 ° C. It is more preferably 600 times or less the viscosity of the ink in the initial state before being left. The reason for this is, for example, in the ink jet recording method, in order to suppress clogging and sticking of ink, ejection is performed for clogging recovery, or a recovery device that sucks ink from the ejection port surface to the device itself. However, if the viscosity of the ink in the state where the water content in the ink is evaporated in the environment of 60 ° C. becomes too large, energy is applied to the ink when ejecting for recovery from clogging. This is also because the energy is absorbed by the viscosity of the ink and the target ejection cannot be performed, or the recovery device cannot operate up to the recovery level. Therefore, due to the correlation between the ink and the recording system such as the inkjet recording system,
The viscosity of the ink in a state where the water content in the ink is evaporated under a temperature environment of 600 ° C. is preferably 600 times or less the initial viscosity of the ink.

On the other hand, the ink of the present invention has fluidity as a whole in a state where water in the ink is evaporated under an environment of 60 ° C., and an initial component of the ink is at least a coloring material, water, and Even if the ink is composed of a liquid medium that dissolves or disperses in water, and the ink is allowed to stand again at 25 ° C. from the state where water in the ink is evaporated at 60 ° C., the fluidity of the entire ink is not lost. Those are particularly preferable. The reason for this is that, for example, when the ink of the present invention is used in an inkjet recording method, preheating is generally performed in order to improve the ejection property of the ink while the entire apparatus used in the method is energized. This is because the temperature conditions are different, depending on the recording system, but generally a temperature of about 25 ° C. to 35 ° C. is applied.

That is, for example, in a poor environment such as 60 ° C., even if the ink has fluidity in a state where the water content in the ink is evaporated from the ink ejection port, a low temperature such as 10 ° C. or lower is obtained thereafter. Even when the environment is low and little external energy is applied to dissolve each compound in the ink,
By the preheating operation in the inkjet recording system,
Since the ink is placed at an ambient temperature of about 25 to 35 ° C, even if the ink in the ink is allowed to evaporate in the 60 ° C environment and the ink is allowed to stand again in the 25 ° C environment, the fluidity of the entire ink remains unchanged. Those that are not lost have excellent ink ejection stability and anti-clogging properties.

In the ink of the present invention, a water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid or carboxylic acid as a water-soluble group in a free acid state is used as a coloring material. Is preferably used together with. Considering the long-term stability of the ink, the environment in which the ink is placed (high temperature and low temperature), the pH of the ink, and the like, the water-soluble polymer compound is particularly preferably one having no ester bond. This is because there is a sufficient possibility that the ester bond is broken in the above environment to generate alcohol, and after leaving the ink having the water-soluble polymer compound having an ester bond in the above environment. This is because, when recording is performed using the ink, the quality of the recorded image may deteriorate, although it depends on the design of the ink.

The water-soluble polymer compound preferably has only anionic polarity. This is because if the compound has a cationic property, it may react in the compound itself depending on the environment surrounding the ink.

The above water-soluble polymer compound has a molecular weight of 2,0 depending on the design and purpose of use of the ink.
It is preferably in the range of 00 to 12,000. When the molecular weight is less than 2,000, the stability of the water-soluble polymer compound is low, and when the molecular weight exceeds 12,000, for example, when it is used in an ink jet recording system, an excessive increase in viscosity may occur. Defect occurs. In addition, when the water-soluble polymer compound is in the form of a salt, the inkjet recording suitability is further improved by using two or more types of counterions, although the reason is not clear.

The coloring material used in the present invention is preferably an anionic dissolution type coloring material. The reason for this is, for example, that the water-soluble polymer compound preferably used in the present invention is an anionic dissolution type,
This is because it is considered that the repulsion between the same polarities is necessary for the entire ink to have fluidity in a state where the water in the ink is evaporated under the environment. However, in order for the entire ink to have fluidity, it is not only due to the repulsion between the same polarities described above, but it is clear that some colorants of the same type have fluidity and some do not. I don't understand. However, a coloring material having the same water-soluble group as that used in the water-soluble polymer compound is preferable. Further, in the above, it is more preferable that the same water-soluble group as the water-soluble polymer compound contained in the coloring material is more than half of the total number of water-soluble groups in the coloring material.

Specific examples of the color material as described above are as follows.
As shown below, the present invention is limited to these specific examples.
is not. A coloring material represented by the following general formula (I) in a free acid state: Ar¹N = NJX (NR¹LNR^TwoX)_nJN = NAr^Two (I) (In the formula, J represents the following formula.Ar¹And Ar^TwoAre each independently an aryl group or a substituted group.
Reel base, Ar¹And Ar^TwoAt least one of them
At least one substituent selected from COOH and COSH
Have. R¹And R^Two Are independently H, an alkyl group, a substituted group
An alkyl group, an alkenyl group or a substituted alkenyl group,
L represents a divalent organic connecting group, and n represents 0 or 1. X
Are each independently a carbonyl group or the following (1) to (3)
It represents a group represented by the formula.

[0020](Z is NR independently^Three R^Four, SR^FiveOr OR^FiveAnd Y
Is H, Cl, Z, SR⁶Or OR⁶And E is Cl or
Represents CN. R^Three, R^Four, R^FiveAnd R⁶H and A independently
Alkyl group, substituted alkyl group, alkenyl group, substituted alkene group
A nyl group, an aryl group, a substituted aryl group, an aralkyl group,
Represents a substituted aralkyl group, R^ThreeOr R^FourTogether with the nitrogen atom
It may form a 5- or 6-membered ring. ) Further, the compound represented by the general formula (I) is at least SO
_ThreeHave the same number of groups selected from COOH or COSH as H
I do. )

Specific examples of the coloring material represented by the general formula (I) include the following.

[0022]

A coloring material represented by the following general formula (II) in a free acid state (In the formula, Ar and Ar ¹ each represent an aryl group or a substituted aryl group, and at least one of Ar and Ar ¹ is CO
It has a substituent selected from OH or COSH. J and J ¹ each have a structure selected from the group consisting of the following general formulas (4), (5) and (6).

[0024] (In the formula, R ⁵ is independently H, an alkyl group, a substituted alkyl group, an alkoxy group, halogen, CN, ureido and N.
Selected from HCOR ⁶ . R ⁶ is selected from H, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group and a substituted aralkyl group. T represents an alkyl group and W is selected from H, CN, CONR ¹⁰ R ¹¹ , pyridinium and COOH. (M) shows an alkylene chain having 2 to 8 carbon atoms, B is H, an alkyl group and COOH
Is selected from R ¹⁰ and R ¹¹ are each selected from H, an alkyl group and a substituted alkyl group. ).

R ¹ , R ² , R ³ and R ⁴ are each selected from H, an alkyl group and a substituted alkyl group, L represents a divalent organic bonding group, and n represents 0 or 1. X is a carbonyl group or a structure represented by the following general formula (7), (8) or (9).

[0026] (In the formula, Z is selected from OR ⁷ , SR ⁷ and NR ⁸ R ⁹ , Y is selected from H, Cl, CN and Z, and E is Cl.
And CN. R ⁷ , R ⁸ and R ⁹ are H,
It is selected from alkenyl groups, substituted alkenyl groups, alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, aralkyl groups and substituted aralkyl groups. Further R ⁸ and R ⁹
May form a 5- or 6-membered ring with the nitrogen atom to which they are attached. When the general formula (II) has no SO ₃ H group, it has at least two groups selected from COOH groups or COSH groups, and when the general formula (II) has an SO ₃ H group, CO
A group selected from an OH group and a COSH group is at least SO
_It has more than the same number of ₃ H groups. )

As the coloring material represented by the general formula (II),
Specific examples include the following.

[0028]

[0029]

[0030]

[0031]

A coloring material represented by the following general formula (III) in the form of free acid: (In the formula, R ₁ and R ₂ are independently selected from a hydrogen atom, a carboxyl group, a sulfone group and an alkyl group having 1 to 2 carbon atoms, and X and Y are independently NR ₃ R ₄ and NR ₅ R ₆ R ₃ and R ₄ are each independently selected from an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, a substituted aralkyl group, an alkoxyl group and a substituted alkoxyl group, and R ₅ is a hydrogen atom, It is selected from an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group, a substituted aralkyl group, an alkoxyl group and a substituted alkoxyl group, and R ₆ is COSH or COO.
Represents a colorless organic residue substituted with H. )

Specific examples of the compound represented by the general formula (III) include the following.

A coloring material represented by the following general formula (IV) in a free acid state (In the general formula (IV), R ₁ , R ₂ and R ₂ ′ are each selected from a carboxyl group, a sulfone group, a hydroxyl group, an amino group, an alkyl group having 1 to 2 carbon atoms and a hydrogen atom, and R ₃ ,
R ₄ , R ₅ and R ₆ are selected from a carboxyl group, a sulfone group, an amino group, a hydroxyl group, an alkylamide group and a hydrogen atom.

X has a structure represented by the following general formula (A) or (B). (In the above general formulas (A) and (B), R ₇ is selected from a carboxyl group, a sulfone group and a hydrogen atom. R ₈ and R ₉ are a carboxyl group, a sulfone group, a structure represented by the following formula and hydrogen. Selected from the group. (In the above formula, n represents an integer of 1 to 5 and m represents 0 or 1, respectively.))

Specific examples of the coloring material represented by the general formula (IV) include the followings.

[0037]

[0038]

[0039]

[0040]

In the coloring material used in the present invention, the water-soluble group species of the coloring material in the free acid state and the water-soluble group species of the water-soluble polymer compound are the same kind, and When the number of water-soluble groups in the coloring material is equal to or more than the number of other water-soluble groups in the coloring material, the reliability tends to be better. Further, taking into consideration the improvement of the water resistance of the recorded matter, it is particularly preferable that the water-soluble group in the above case is a carboxylic acid in the free acid state.

The liquid medium used in the present invention is preferably a mixture of water and a water-soluble organic solvent. Specific examples of the water-soluble organic solvent include, for example, amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Ethylene glycol, propylene glycol, butylene glycol,
Alkylene glycols having an alkylene group of 2 to 6 carbon atoms such as triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether , Diethylene glycol monomethyl (or ethyl) ether,
Lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether;
-Methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sulfolane,
Examples thereof include cyclic amide compounds such as dimethyl sulfoxide, 2-pyrrolidone and ε-caprolactam, and imide compounds such as succinimide.

The content of the above water-soluble organic solvent is generally preferably 1 to 40% by weight, more preferably 3 to 30% by weight, based on the total weight of the ink. The water content of the ink is 30 to 95 with respect to the total weight of the ink.
Used in the range of weight percent. If it is less than 30% by weight, the solubility of the dye is deteriorated and the viscosity of the ink is increased, which is not preferable. On the other hand, if it is more than 95% by weight, the amount of vaporized components is too large to satisfy the sufficient fixing property.

The ink of the present invention contains an anti-kogation agent in order to prevent such an adverse effect of the ink, because impurities such as inorganic ions in the ink cause a problem of kogation in an ink jet recording method. You should do it. However, these anti-kogation agents also have a correlation with the surface state of the heater that transfers heat energy, and thus may not be added depending on the case. Further, if the inorganic ion in the ink is 1 ppm, preferably 0.5 ppm or less, it may not be added. The content in the ink is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight, based on the total weight of the ink.
It is.

Further, the ink of the present invention contains urea,
It is preferable to contain thiourea and derivatives thereof. The content of these substances in the ink is 0.1 to 50% by weight, preferably 1 to 30% by weight, more preferably 2 to 10% by weight, based on the total weight of the ink.

Further, a monohydric alcohol may be added to the ink of the present invention as a fixing agent for the ink. Further, the nonionic surfactant also functions as a fixing agent. These are necessary in order to prevent color mixture bleeding that occurs at the boundary when different color tones are printed. Further, it is preferable that these are contained in the ink also in the sense that the solubility of the dye in the ink is stably improved. In that case, a nonionic surfactant is preferable in view of the amount added to the ink and the effect.

Specific examples of the monohydric alcohol which can be added to the ink of the present invention as a fixing agent include ethanol, isopropyl alcohol and n-butanol.
Specific examples of the nonionic surfactant that can be added in the same manner include polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, and polyoxyethylene-
Examples thereof include polyoxypropylene glycol, polyoxyethylene-polyoxypropylene alkyl ether, and acetylene glycol polyethylene oxide adduct, but preferably nonylphenyl ether EO adduct,
Ethylene oxide-propylene oxide copolymer (EO-PO copolymer) and acetylene glycol polyoxyethylene oxide adduct are preferable, and more preferably acetylene glycol polyoxyethylene oxide adduct represented by the following general formula (V) ( Acetylene glycol EO adduct).

[0048] The content of the monohydric alcohol or nonionic surfactant ink is 0.1 to 20% by weight based on the total weight of the ink.
Preferably it is 0.5 to 10% by weight. If it is less than 0.1% by weight, it is not effective as a fixing agent, and it is 20% by weight.
If the amount is larger, the balance of print quality becomes poor, for example, the balance between density and fixability or feathering, which is a whisker-like blur, and fixability and density.

The ink of the present invention is particularly suitable when applied to an ink jet recording method of the type in which the ink is ejected by the bubbling phenomenon of the ink due to heat energy.
Discharge is extremely stable and satellite dots are not generated. However, in this case, the thermal physical property value (for example, specific heat, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

Further, the ink of the present invention solves the problem of the water resistance of the ink on the recorded matter when recorded on plain paper or the like, and at the same time, improves the matching with the ink jet head. Surface tension at 25 ° C is 20-55 dyne / cm, viscosity is 1
It is desired to be adjusted to 5 cP or less, preferably 10 cP or less, more preferably 5 cP or less, but it is not limited to this because it depends on the state of the inkjet recording head. Therefore, in order to adjust the ink to the above physical properties and solve the problem in plain paper, the amount of water contained in the ink of the present invention is 50% by weight or more and 9% or more.
It is suitable to be 8% by weight or less, preferably 60% by weight or more and 95% by weight or less.

The ink of the present invention is particularly suitable for use in an ink jet recording method in which droplets are ejected by the action of heat energy for recording, but it can also be used for general writing instruments. As a method and apparatus suitable for performing recording using the ink of the present invention, a method and apparatus for applying thermal energy corresponding to a recording signal to the ink in the chamber of the recording head and generating droplets by the thermal energy are provided. Can be mentioned.

An example of the head structure, which is the main part of the apparatus, is shown in FIGS. 1, 2 and 3. The head 13 includes a glass, ceramics or plastic plate having a groove 14 through which ink passes, and a heating head 15 (thin film head is shown in the figure, but not limited to this) used for thermal recording. Obtained by gluing. The heating head 15 includes a protective film 16 made of silicon oxide and the aluminum electrode 1.
7-1 and 17-2, a heating resistor layer 18 made of nichrome, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina.

The ink 21 has a discharge orifice (fine hole) 2
2, and the meniscus 23 is formed by the pressure P. Now, when an electric signal is applied to the aluminum electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 rapidly heats up, bubbles are generated in the ink 21 in contact therewith, and the meniscus is generated by the pressure. 23 is ejected, the ink 21 is ejected, becomes an ink droplet 24 from the orifice 22, and is ejected toward the recording material 25. FIG. 3 shows an external view of a multi-head in which many heads shown in FIG. 1 are arranged.
The multi-head is a glass plate 27 having multi-grooves 26.
Then, a heating head 28 similar to that described with reference to FIG. 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.

FIG. 4 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end, and forms a cantilever. The blade 61 is a recording head 65
It is arranged at a position adjacent to the recording area according to (3), and in the case of this example, it is held in a protruding form in the moving path of the recording head 65. Reference numeral 62 denotes a cap, 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, and contacts the ink ejection port surface,
A structure for performing capping is provided. Further, an ink absorber 63 is 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 water, dust, and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head which has an ejection energy generating means and ejects ink to a recording material facing the ejection port surface where the ejection ports are arranged to perform recording, and 66 is equipped with the recording head 65. A carriage for moving the recording head 65. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected (not shown) to a belt 69 driven by a motor 68.
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 52 denotes a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to the position facing the ejection port surface of the recording head 65, and is ejected to the ejection section provided with the ejection roller 53 as the recording progresses.

In the above configuration, when the recording head 65 returns to the home position at the end of recording or the like, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 projects into the moving path. I have. As a result, the ejection port surface of the recording head 65 is 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 in the same positions as the above wiping positions. 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 to the home position adjacent to the printing area. Then, the wiping is performed along with this movement.

FIG. 5 is a diagram showing an example of an ink cartridge 45 in which the ink is supplied to the head through an ink supply member, for example, a tube. 40 here
Is an ink storage portion that stores 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 this 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 for the present invention that the ink container has a surface in contact with the ink made of polyolefin, particularly polyethylene. The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separate from each other as described above, and is preferably used in the one in which they are integrated as shown in FIG.

In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink containing portion containing ink, for example, an ink absorber is contained, and the ink in the ink absorber has a plurality of orifices. Head portion 71
Are ejected as ink droplets from the ink. It is preferable for the present invention to use polyurethane, cellulose or polyvinyl acetal as the material of the ink absorber. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. The recording unit 70 is used in place of the recording head shown in FIG.
It is detachable from the carriage 66.

The ink of the present invention has the following preferable conditions:
Since an anionic dissolution or dispersion type compound is used in combination, the pH of the ink is preferably 8 or more. However, when used in the ink jet recording method, the pH is 8.5 or more, more preferably 9.0 or more, in consideration of reliability such as ejection property. The pH of the ink of the present invention may be adjusted with a nitrogen-containing compound or a divalent metal. The ink of the present invention contains, in addition to the above components, a water-soluble organic solvent, a surfactant, an anticorrosive agent, an antifungal agent, an antioxidant, an evaporation accelerator, a chelating agent, a water-soluble polymer, etc., if necessary. Various additives may be added.

[0061]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the text, "part" and "%" are based on weight unless otherwise specified.

Examples 1 to 4 and Comparative Examples 1 to 3 <Preparation of Ink> The following components were mixed, thoroughly stirred and dissolved, and then a fluoropore filter having a pore size of 0.4 μm (trade name: Sumitomo Electric Industries, Ltd.). (Manufactured by Inc.) under pressure filtration,
Inks of the present invention and comparative examples were prepared respectively.

Example 1 C. I. Direct Black 195 3.0% Thiodiglycol 10.0% Diethylene glycol 10.0% Polyacrylic acid ammonium salt with a molecular weight of 5,000 1.0% Pure water 76.0%

Example 2 C. I. Direct Black 195 2.5% Glycerin 10.0% Isopropyl alcohol 3.0% Polyacrylic acid triethanolamine salt with a molecular weight of 5,000 0.5% Polyacrylic acid sodium salt with a molecular weight of 10,000 0.4% Pure water 85.4%

Example 3 Dye 5 3.0% 2-Pyrrolidone 10.0% Ethanol 4.0% Polyacrylic acid triethanolamine salt having a molecular weight of 7,800 1.0% Polyacrylic acid ammonium salt having a molecular weight of 3,000 1.0% Compound of general formula (V) (in the formula, a = b = 1, m + n = 15) 1.0% Pure water 80.0%

Example 4 Dye 1 2.5% Glycerin 7.0% Urea 10.0% Ethanol 3.0% Polyacrylic acid ammonium salt with a molecular weight of 5,000 2.0% Pure water 75.5%

Comparative Example 1 C.I. I. Direct Black 195 3.0% Thiodiglycol 10.0% Diethylene glycol 10.0% Pure water 77.0%

Comparative Example 2 C.I. I. Direct Black 51 2.0% Thiodiglycol 10.0% Diethylene glycol 10.0% Polyacrylic acid ammonium salt with a molecular weight of 5,000 1.0% Pure water 76.0%

Comparative Example 3 C.I. I. Food Black 2 3.0% Glycerin 10.0% Isopropyl alcohol 3.0% Polyacrylic acid sodium salt with a molecular weight of 10,000 1.0% Pure water 83.0%

<Confirmation of fluidity> The fluidity of each of the obtained inks was confirmed by the following method.

(1) Fluidity (A) 100 g of the sample ink was placed in a 100 cc glass beaker and left in an oven at 60 ° C. and 20% RH for 5 days, and the condition was evaluated according to the following criteria.

(2) Fluidity (B) 100 g of the sample ink was placed in a 100 cc glass beaker and left in an oven at 60 ° C. and 20% RH for 5 days, and then the glass beaker was further left in 25 ° C. for 5 days. The subsequent state was evaluated according to the following criteria. ◯: No deposit was observed on the ink surface, and the inside of the ink was fluid. Also, when the beaker was turned upside down, the ink flowed down. Δ: Precipitates are recognized on the ink surface, but the inside of the ink is fluid. However, the ink is in a viscous state.
Moreover, the ink did not flow down even when the beaker was turned upside down. X: Precipitates were observed on the ink surface, and the inside of the ink was in the same state as the surface, and no fluidity was observed. or,
Ink did not flow down when the beaker was turned upside down.

<Evaluation Test> Next, with respect to the inks of Examples 1 to 4 and Comparative Examples 1 to 3 obtained as described above, BJC-600J (using a heating element as an ink ejection energy source was used as an ink jet recording apparatus. The following evaluations were performed using a trade name: manufactured by Canon Inc., and the results are summarized in Table 1.

<Evaluation Method and Evaluation Criteria> (1) Water Resistance After filling a printer with a predetermined ink and printing alphanumeric characters and solid portions on commercially available acid paper, the printing was stopped,
After leaving the printed matter for one hour or more, the print density was adjusted to Macbeth RD9.
15 (trade name: manufactured by Macbeth). After that, the printed matter was immersed in a container filled with water for 3 minutes or more, then left to stand and dried, the print density was measured again, the residual rate of the print density was determined, and the water resistance was evaluated. ◯: The residual rate of printed matter density is 80% or more. Δ: The residual density of the printed matter is 65% or more and less than 80%. X: The residual density of the printed matter is less than 65%.

(2) Frequency Responsiveness The printed state of the obtained printed matter, that is, the state of blurring or white spots and the state of defective landing point such as slushing or twisting was visually observed and evaluated. ◯: The ink follow-up state with respect to the frequency is almost good, and no blur, white spots, and defective landing point are not seen in character printing, but slight blur is seen in solid printing. Δ: No smearing or white spots are observed in character printing, but defective landing points are partially observed. Further, in solid printing, blurring and white spots are seen in about 1/3 of the whole solid printing. X: Many solid lines and white spots in solid printing, and many thin lines and defective landing spots in character printing.

(3) Evaluation of printing quality After printing alphanumeric characters on a commercially available plain paper sheet with a printer and leaving the printed material for 1 hour or more, the sharpness of the characters and the whisker-like character generated from the characters can be visually observed with a microscope. The degree of bleeding was evaluated. A: The characters are sharp and have no whisker-like bleeding. ◯: The characters are sharp, but some beard-like bleeding occurs. Δ: Characters are not sharp. Or, there is a slight amount of beard-like bleeding. X: Characters are not sharp and have many beard-like blurs.

(4) Evaluation of anti-clogging property The BJC600 was filled with each ink, left in an environment of 50 ° C. for 1 week, and the anti-clogging property was determined according to the number of recovery operations until normal ejection. It was evaluated according to the standard. ◯: Normal ejection was performed within 5 times of recovery operation. Δ: Normal ejection was performed after 6 to 10 times of recovery operation. X: Normal ejection was not performed even after 11 recovery operations.

(5) Evaluation of Adhesiveness BJC600 was filled with each ink, left for 1 week in an environment of 50 ° C., and then left for 1 week in an environment of 5 ° C.
The adherence was evaluated according to the following criteria by the number of recovery operations until normal ejection. ◯: Normal ejection was performed within 5 times of recovery operation. Δ: Normal ejection was performed after 6 to 10 times of recovery operation. X: Normal ejection was not performed even after 11 recovery operations.

Table 1: Evaluation results of Examples and Comparative Examples

[0080]

As described above, according to the present invention,
An ink that gives a high-quality image when printed on plain paper used in general offices, etc., has excellent ink stability and reliability, and also has good water resistance. A recording method and a device using such an ink can be provided. Further, according to the present invention,
An ink that has good stability even after long-term storage and can perform reliable recording without any problems even when used in an inkjet recording system, an inkjet recording method using the same, and a device using the ink Can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a head section of an ink jet recording apparatus.

FIG. 2 is a cross-sectional view of a head section of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG. 1;

FIG. 4 is a perspective view illustrating an example of an ink jet recording apparatus.

FIG. 5 is a vertical sectional view of the ink cartridge.

FIG. 6 is a perspective view of a recording unit.

FIG. 7 is a diagram showing the relationship between pH and viscosity of the ink of the present invention.

FIG. 8 is a graph showing the relationship between pH and solubility of compounds used in the present invention.

[Explanation of symbols]

 61: Wiping member 62: Cap 63: Ink absorber 64: Ejection recovery section 65: Recording head 66: Carriage

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 6, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a head section of an ink jet recording apparatus.

FIG. 2 is a cross-sectional view of a head section of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG. 1;

FIG. 4 is a perspective view illustrating an example of an ink jet recording apparatus.

FIG. 5 is a vertical sectional view of the ink cartridge.

FIG. 6 is a perspective view of a recording unit.

[Explanation of reference numerals] 61: Wiping member 62: Cap 63: Ink absorber 64: Ejection recovery section 65: Recording head 66: Carriage

Claims (31)

[Claims] 1. The ink as a whole has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C., and an initial component of the ink is at least a coloring material, water, and dissolved or dispersed in water. An ink comprising a liquid medium that 2. The ink according to claim 1, wherein no deposit is generated at the gas-liquid interface in a state where water in the ink is evaporated under an environment of 60 ° C. 3. The ink as a whole has fluidity in a state where water in the ink is evaporated in a 60 ° C. environment, and the viscosity of the ink in that state has a water content in the ink in a 60 ° C. environment. The ink according to claim 1 or 2, which has a viscosity of 600 times or less of an initial viscosity of the ink before being evaporated. 4. A state where the water content in the ink is evaporated under the environment of 60 ° C. and the entire ink is fluid, and the water content in the ink is evaporated under the environment of 60 ° C. 25 The ink according to claim 1, wherein the fluidity of the ink is not lost even when the ink is left to stand again in an environment of ° C. 5. The ink as a whole has fluidity when the water content in the ink is evaporated at 60 ° C.
From the state where the water in the ink is evaporated in the 0 ° C environment, 25
Even when left in a ℃ environment, the fluidity of the ink is not lost,
The ink according to claim 4, wherein no precipitate is generated at the gas-liquid interface. 6. The ink as a whole has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C.
From the state where the water in the ink is evaporated in the 0 ° C environment, 25
Even when left in a ℃ environment, the fluidity of the ink is not lost,
The viscosity of the ink that has not lost its fluidity under a 25 ° C. environment is 600 times or less than the viscosity of the ink in the initial state before evaporating the water content in the ink under a 60 ° C. environment. Ink described in. 7. The ink as a whole has fluidity in a state where water in the ink is evaporated under an environment of 60 ° C., and an initial component of the ink is at least a coloring material, water, and dissolved or dispersed in water. The ink according to any one of claims 1 to 6, which comprises a liquid medium to be used and a water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid, and carboxylic acid as a water-soluble group in a free acid state. . 8. The water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid, and carboxylic acid as a water-soluble group in a free acid state is a compound having no ester bond. Item 7. The ink according to Item 7. 9. The water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid or carboxylic acid as a water-soluble group in a free acid state is an anionic compound. Ink. 10. A water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid and carboxylic acid as a water-soluble group in a free acid state has a molecular weight of 2,
The ink according to claim 9, which is in the range of 000 to 12,000. 11. The water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid or carboxylic acid as a water-soluble group in a free acid state is composed of two or more salts. The ink according to item 10. 12. The ink according to claim 1, wherein the coloring material is an anionic coloring material. 13. A water-soluble group of a coloring material in a free acid state,
The water-soluble group of the water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid, or carboxylic acid as a water-soluble group in a free acid state, which is the same kind. The ink according to item 11, 11 or 12. 14. The water-soluble group of the coloring material in the free acid state is
The water-soluble group of the water-soluble polymer compound having a plurality of at least one selected from phosphoric acid, sulfonic acid or carboxylic acid as a water-soluble group in the free acid state is the same.
The ink according to claim 13, wherein the number of the water-soluble groups is equal to or more than the number of other water-soluble groups included in the coloring material. 15. The ink according to claim 14, wherein the water-soluble group is a carboxylic acid in a free acid state. 16. In an inkjet recording method for recording on a recording material by ejecting ink droplets from an orifice of a recording head according to a recording signal, inkjet recording using the ink according to any one of claims 1 to 15. Method. 17. The ink jet recording method according to claim 16, wherein the ink is made fluid by heat energy and the ink is ejected as droplets from the orifice by the fluidity. 18. A recording unit comprising an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets, wherein the ink is contained in any one of claims 1 to 1.
A recording unit which is the ink according to item 5. 19. The recording unit according to claim 18, wherein the head portion has a head for ejecting the ink as droplets from the orifice by the fluidity generated by thermal energy. 20. The recording unit according to claim 19, wherein the ink containing portion has an ink holder inside. 21. The recording unit according to claim 20, wherein the ink containing portion has an ink holder made of polyurethane, cellulose or polyolefin. 22. The recording unit according to claim 21, wherein the ink containing portion has an ink sparse / dense state inside. 23. An ink cartridge comprising an ink containing portion containing ink, wherein the ink is
An ink cartridge comprising the ink according to any one of items 1 to 15. 24. The ink cartridge according to claim 23, wherein the ink containing portion has a liquid contact surface formed of polyolefin. 25. An ink jet recording apparatus comprising a recording unit having an ink containing section containing ink and a head section for ejecting the ink as ink droplets, wherein the ink is according to any one of claims 1 to 15. Inkjet recording device that is ink. 26. The ink jet recording apparatus according to claim 25, wherein the head portion is a head which makes the ink fluid by heat energy and ejects the ink as droplets from the orifice by the fluidity. 27. The ink jet recording apparatus according to claim 26, wherein the ink containing portion has an ink holder inside. 28. The ink jet recording apparatus according to claim 27, wherein the ink containing portion has an ink holder made of polyurethane, cellulose or polyolefin. 29. An ink jet recording apparatus comprising a recording head for ejecting ink droplets, an ink cartridge having an ink accommodating portion for accommodating ink, and an ink supply portion for supplying ink from the ink cartridge to the recording head. An ink jet recording apparatus, wherein the ink is the ink according to any one of claims 1 to 15. 30. The ink jet recording apparatus according to claim 29, wherein the recording head is a head which makes the ink fluid by heat energy and ejects the ink as droplets from the orifice by the fluidity. 31. The ink jet recording apparatus according to claim 30, wherein the ink containing portion has a liquid contact surface formed of polyolefin.