JPH0570727A - Ink, ink jet recording method using the same, and apparatus for using the same - Google Patents

Abstract

PURPOSE:To provide an ink which gives a printed material having printed part which dries well and does not stain the material, can form a high-quality printed image comprising circular dots with no irregular blur, causes no clogging in a nozzle out of use during recording nor clogging in a printer head of a printer in a temporary or long-term suspension, and enables an easy restoration even when clogging should occur. CONSTITUTION:A diester of a dicarboxylic acid and a monohydric aliph. alcohol are incorporated as the essential components into an ink contg. a water-sol. dye, a water-sol. org. solvent, and water.

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 same, and a device using the ink. More specifically, the present invention has excellent ink clogging prevention properties and is used in general offices and the like. The present invention relates to an ink capable of excellent recording even on existing plain paper, an inkjet recording method using the same, and a device using the ink.

[0002]

2. Description of the Related Art Writing instruments (fountain pens, felt-tip pens,
With regard to inks for water-based ballpoint pens and the like and ink jet inks, various compositions have been reported. In particular, the composition and physical properties of the ink are used so that good recording can be performed on plain paper such as copy paper, report paper, notebook, notepaper, bond paper, and continuous slip paper that are commonly used in offices in recent years. Detailed research and development has been carried out from various aspects such as. For example, in general, the ink contains a high boiling point organic solvent such as glycol for the purpose of preventing drying and clogging, but when recording is performed on plain paper with a high degree of size using such an ink. Since the ink does not easily penetrate into the inside of the paper and the drying property of the recording part is poor, there is a problem of fixing property such as ink getting on the hand when touching the recorded matter or characters are rubbed and stained. It was

On the other hand, in order to enhance the permeability of the ink into the inside of the paper, JP-A-55-29546 proposes a method of adding a large amount of a surfactant to the ink. However, in this case, depending on the type of paper, bleeding occurs very much, when the writing instrument is filled with ink, the ink drops from the pen tip, and when it is filled in the inkjet head, Depending on the structural conditions, there were problems such as ink retreating from the orifice surface and ejection was not performed, and conversely, the entire orifice surface was wet and ink was not ejected.

Further, in JP-A-54-104933 and JP-B-62-14189, N, N
N-bis (polyoxyethylene (or propylene))-
A method of adding P-toluenesulfonic acid amide or the like is disclosed, and although this method is effective for improving the solubility of the dye, in order to sufficiently prevent clogging,
Since a considerably large amount of organic solvent such as polyhydric alcohol is required to be used in combination, the drying property on the recording material such as paper is poor, and there is a problem that stain occurs due to contact even after a long time. Therefore, in order to improve the penetrability into paper, it is required to use a surfactant together, and as a result, bleeding occurs and the printing quality is not sufficient.

Further, when the ink is used for ink jet recording and ink discharge is interrupted, when the water or the like evaporates, the above compound recedes from the orifice surface, and there is a problem that the clogging prevention property is poor. In addition to the above, various improvements have been attempted up to now, but an ink capable of sufficiently solving all of the above-mentioned problems of drying property, printing quality and clogging property has not been known so far. is the current situation.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to form round dots which have a good drying property of a recording portion with respect to a recording material, do not stain a recorded matter, and have less irregular bleeding. When high quality images can be formed, and the clogging of unused nozzles during recording and the clogging of the printer head when the printer is temporarily stopped or stopped for a long period of time can be prevented and clogging should occur However, it is an object of the present invention to provide an ink whose recovery is easy, an ink jet recording method using the ink, and a device using the ink.

[0007]

The above object can be achieved by the present invention described below. That is, the present invention is an ink containing a water-soluble dye, a water-soluble organic solvent and water, which is characterized by having a dicarboxylic acid diester and an aliphatic monohydric alcohol as essential components, and an inkjet recording using the same. Methods and devices using such inks.

[0008]

The present inventors have conducted extensive studies on various ink compositions, and as a result, by incorporating dicarboxylic acid diester and aliphatic monohydric alcohol in the ink,
It has been found that the so-called plain paper, which is generally used in offices and the like, has a good drying property of the recording portion, does not stain the recording portion, and can obtain a high-quality image with less bleeding. The above-mentioned action can be obtained to some extent in an ink system using an aliphatic monohydric alcohol alone, but in an ink system in which a dicarboxylic acid diester and an aliphatic monohydric alcohol are used together, a synergistic effect of both is achieved. With such a function, it is possible to further improve the performance (particularly, the drying property of the recorded image) as compared with the system used alone. Further, when the dicarboxylic acid diester is contained in the ink, the clogging prevention property is improved, and in particular, the ink at the tip of the unused nozzle of the printer head during recording is evaporated, and the viscosity or dye is deposited, It has been found that the time until printing failure such as ejection failure or twisting (decrease in landing point accuracy) becomes extremely long. In addition, by any chance,
It has been found that even when the volatile component in the ink at the nozzle tip of the printer head is completely evaporated, the recoverability becomes very easy. Although the mechanism of such a phenomenon is not clear, the inclusion of a dicarboxylic acid diester in the ink improves the dye solubility, suppresses the increase in the viscosity when the ink evaporates, and prevents the aggregate deposition of the dye when the volatile components are completely evaporated. It is presumed that this is due to the action of relaxing. Due to such effects, the number of times of clogging recovery operation in the printer system and the ink consumption accompanying it can be reduced as much as possible, so it is possible to use the predetermined ink amount mounted in the printer more efficiently than before. Also, the reliability of the printer system is increased. As described above, in order to achieve the object of the present invention, it is necessary to use a dicarboxylic acid diester and an aliphatic monohydric alcohol in the ink as essential components, and even if either one is lacking. However, the complete achievement of the purpose cannot be achieved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. Dicarboxylic acid diester used in the present invention, dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, diethyl fumarate, dimethyl succinate, diethyl succinate,
Fats such as diphenyl succinate, dimethyl malonate, diethyl malonate, diphenyl malonate, dimethyl phthalate, diethyl phthalate, dimethyl adipate, diethyl adipate, dimethyl mesaconate, diethyl mesaconate, dimethyl citraconic acid, diethyl citraconic acid Examples include aromatic dicarboxylic acid diesters and aromatic dicarboxylic acid diesters. Among them, diethyl maleate, diethyl fumarate, dimethyl succinate, dimethyl mesaconate, and dimethyl citraconate prevent clogging, especially the clogging prevention effect of the nozzle tip of the unused nozzle during recording and recording by combination with aliphatic monohydric alcohol. It is particularly preferable because it has an excellent effect of improving the drying property of the part. The above dicarboxylic acid diesters can be used alone or in combination. The content of the dicarboxylic acid diester is generally 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total weight of the ink. If it is less than 0.1% by weight, the desired effect is insufficient, and if it exceeds 5% by weight, irregular bleeding tends to occur. Next, examples of the aliphatic monohydric alcohol used in the present invention include methyl alcohol, ethyl alcohol, propyl alcohol, n-isopropyl alcohol, n-butyl alcohol, and 2-butyl alcohol. Ethyl alcohol, isopropyl alcohol, and 2-butyl alcohol are particularly preferable from the viewpoints of improving the drying property of the recording area while maintaining the odor and odor and safety. The content of the aliphatic monohydric alcohol is generally 0.1 to 10 relative to the total weight of the ink.
% By weight, preferably 0.5-5% by weight.

As the water-soluble dye used in the present invention, almost all of the acid dyes, direct dyes, basic dyes, and reactive dyes described in the Color Index can be used. Further, even those not described in the color index can be used as long as they are water-soluble dyes. The amount of these dyes to be used is not particularly limited, but generally 0.1 to the total weight of the ink.
The range is preferably from 15 to 15% by weight, more preferably from 0.1 to 1
It is 0% by weight.

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, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol,
Alkylene glycols in which an alkylene group such as diethylene glycol contains 2 to 6 carbon atoms; glycerin; ethylene glycol dimethyl (or ethyl) ether, diethylene glycol dimethyl (or ethyl) ether,
Lower alkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether; N-
Methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sulfolane, dimethyl sulfoxide and the like can be mentioned.

The content of the water-soluble organic solvent is generally preferably 1% to 40% by weight, more preferably 3% to 30%, based on the total weight of the ink. Especially, the amount of the wetting agent generally used for the purpose of preventing clogging such as polyhydric alcohol does not need to be used in a large amount due to the effect of the dicarboxylic acid diester of the present invention, and is rather 40% by weight. %, The print fixability and print quality on paper were degraded.
The content of water in the ink is 30 to 95% by weight. If it is less than 30% by weight, the dissolution of the coloring material becomes worse and the viscosity of the ink becomes high, which is not preferable.
On the other hand, if the amount is more than 95% by weight, the amount of vaporized components becomes too large, and sufficient anti-sticking performance cannot be satisfied. In addition to the above components, the ink of the present invention may optionally contain a surfactant, a pH adjustor, a rust preventive, an antiseptic, a fungicide,
Various additives such as antioxidants, chelating agents and water-soluble polymers may be added.

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 thermal energy,
The ejection is extremely stable, and satellite dots are not generated. However, in this case, a thermal property value (for example, specific heat, coefficient of thermal expansion, thermal conductivity, etc.) may be adjusted. Furthermore, the ink of the present invention solves the problems of ink bleeding and the dryness and permeability of recorded matter when recorded on plain paper, and at the same time, improves the matching with the inkjet head. Has a surface tension of 30 to 68 dyn at 25 ° C.
It is desirable that e / cm and viscosity are adjusted to 15 cP or less, preferably 10 cP or less, and more preferably 5 cP or less. 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 98% by weight or less, preferably 60% by weight or more 95%. It is preferable that the content be less than or equal to wt%.

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 goes without saying that 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 is made by bonding glass, ceramics or a plastic plate having a groove 14 through which ink is passed, and a heating head 15 (a head is shown in the drawing, but not limited to this) used for thermal recording. Obtained. The heating head 15 includes a protective film 16 made of silicon oxide and an aluminum electrode 17.
1, 17-2, a heat generating resistor layer 18 formed of nichrome, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina.
Has become. The ink 21 reaches the ejection orifice (fine hole) 22 and forms a meniscus 23 by the pressure P. Now, when an electric signal is applied to the electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 rapidly generates heat, and bubbles are generated in the ink 21 in contact with the area, and the meniscus 23 is generated by the pressure. Are ejected, the ink 21 is ejected, and becomes a recording 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 manufactured by closely adhering a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described in FIG. 1 shows the head 13 along the ink flow path.
2 is a cross-sectional view of FIG. 2, and FIG. 2 is a sectional view taken along line AB of 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, which is in the form of a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head, and in the case of this example, it is held in a protruding form in the moving path of the recording head. Reference numeral 62 denotes a cap, which is arranged at a home position adjacent to the blade 61, and has a configuration that moves in a direction perpendicular to the moving direction of the recording head and abuts the ejection port surface to perform capping. Further, 63 is an absorber provided adjacent to the blade 61, and like the blade 61, is held in a protruding form in the moving path of the recording head. The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the absorber 63 remove water, dust, and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head having ejection energy generating means for ejecting ink to a recording material facing the ejection port surface where ejection ports are arranged for recording, and 66 a recording head having the recording head 65 mounted thereon. A carriage for moving 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 its adjacent area. Reference numeral 51 is a paper feed section for inserting a recording material, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the ejection opening surface of the recording head, and is ejected to the ejection section provided with the ejection roller 53 as the recording progresses.

In the above structure, when the recording head 65 returns to the home position after recording is completed, the cap 62 of the head recovery section 64 is retracted from the movement path of the recording head 65, but the blade 61 is projected into the movement path. There is. As a result, the ejection port surface of the recording head 65 is wiped. When the cap 62 comes into contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to project into the movement path of the recording head. Recording head 6
When 5 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same positions as the above-mentioned positions at the time of wiping. As a result, the ejection opening surface of the recording head 65 is wiped even during this movement. To move the recording head to the home position,
Not only at the end of recording or at the time of ejection recovery, the recording head moves to the home position adjacent to the recording area at a predetermined interval while moving in the recording area for recording, and the wiping is performed with this movement. .

FIG. 5 is a diagram showing an example of an ink cartridge in which ink is supplied to the head through an ink supply member, for example, a tube. Here, 40 is an ink containing portion containing 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. 44
Is an absorber that receives waste ink. It is preferable for the present invention that the surface of the ink containing portion which is in contact with the ink is formed 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 separately provided as described above, but is also 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 for containing ink, for example, an ink absorber is contained, and the ink in the ink absorber has a plurality of orifices. Head portion 71
It is configured to be ejected as an ink droplet from. It is preferable for the present invention to use polyurethane, cellulose or polyvinyl acetal as the material of the ink absorber. Reference numeral 72 is an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. This recording unit 70 is shown in FIG.
The recording head is used instead of the recording head and is detachable from the carriage 66.

[0021]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. Examples 1 to 7 and Comparative Examples 1 to 6 The components shown in Table 1 below were mixed, sufficiently stirred and dissolved,
The inks of the present invention and the comparative example were prepared by pressure filtration with a fluoropore filter (trade name: manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 0.45 μm.

[Table 1] Table 1 (Numbers in the table indicate weight%)

[Table 2] Continuation of Table 1 Next, using the inks of Examples 1 to 7 and Comparative Examples 1 to 6 thus obtained, an inkjet printer BJ-130 (trade name: Canon Inc.) that uses a heating element as an ink discharge energy source in an inkjet recording device. Was used to evaluate print dryness, clogging, and print quality. The results are shown in Table 2.

[Evaluation Method and Evaluation Criteria] (1) Printing Dryness Regarding printing dryness, after printing alphanumeric characters on a commercially available continuous slip paper with a printer, 10, 20, 30, 40,
After 50 and 60 seconds, it was rubbed with a filter paper (No. 2 (trade name) manufactured by Toyo Roshi Kaisha, Ltd.) and judged based on the number of seconds until the printed part was not stained (measured at 20 ± 5 ° C. and 50 ± 10% RH). ). ⊚: Less than 10 seconds ◯: Within 10 to 15 seconds Δ: 16 to 30 seconds. X: 31 seconds or more. (2) Evaluation of clogging property (a) After filling a printer with a predetermined ink and continuously printing alphanumeric characters for 10 minutes, the printing is stopped, and the printer is left for a predetermined time without a cap (standing condition: 15 ℃, 10 ±
After 5% RH), alphanumeric characters were printed again, and the judgment was made based on the time period during which the same printing state as the initial state could be maintained. ◯: The time that can maintain the same printing state as the initial time is 1 minute or more. Δ: The time that can maintain the same printing state as the initial time is 30 seconds or more.

(3) Evaluation of clogging property (a) After filling the printer with a predetermined ink and continuously printing alphanumeric characters for 10 minutes, the printing is stopped, the cap is put on, and the cap is left for 30 days. : 60 ° C, 10 ± 5% R
After H), alphanumeric characters were printed again, and judgment was made by the number of recovery operations until the initial printing state was reproduced. ◎: Printing similar to the initial printing is possible without recovery operation ○: Printing similar to the initial printing is possible after 1 to 5 recovery operations △: Printing similar to the initial printing is possible after 6 to 10 recovery operations ×: 11 It is possible to perform the same printing as the initial one with more than one recovery operation. (4) Print quality evaluation After printing commercial copy paper (XEROX 4024), leave it for 1 hour or more, and then bleed at the dot level.
The sharpness of the edge was evaluated under the environmental conditions of 25 ° C. and 60% RH. ◯: There is no bleeding and the edges are sharp. B: Some bleeding is recognized and the edges are slightly blurred. X: There are many blurs and the edges of the dots are blurred.

[Table 3] Table 2

[0024]

As described above, according to the present invention, it is excellent in quality and permeation without bleeding even on ordinary plain paper generally used in office such as copy paper, report paper, notebook, and notepaper. It is possible to record with good performance. Furthermore, with the ink of the present invention, highly reliable recording can be performed without causing clogging of the pen tip of a writing instrument or the nozzle of an inkjet head.

[0025]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a head portion of an inkjet recording apparatus.

FIG. 2 is a cross-sectional view of a head portion of an inkjet recording device.

3 is an external perspective view of a head in which the head shown in FIG.

FIG. 4 is a perspective view showing an example of an inkjet recording apparatus.

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

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

[Explanation of symbols]

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

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C09D 11/02 PTH 7415-4J

Claims (17)

[Claims] 1. An ink containing a water-soluble dye, a water-soluble organic solvent and water, wherein the dicarboxylic acid diester and the aliphatic 1
An ink comprising a hydric alcohol as an essential component. 2. The total amount of dicarboxylic acid diester is in the range of 0.1 to 5% by weight based on the total weight of the ink.
Ink described in. 3. The content of the aliphatic monohydric alcohol is in the range of 0.1 to 5% by weight based on the total weight of the ink.
Ink described in. 4. The content of water is 40 with respect to the total weight of the ink.
The ink according to claim 1, which is in the range of ˜95% by weight. 5. The ink according to claim 1, wherein the content of the water-soluble organic solvent is in the range of 1 to 40% by weight based on the total weight of the ink. 6. An inkjet recording method for recording on a recording material by ejecting ink droplets from an orifice according to a recording signal, wherein the ink is the ink according to claim 1. .. 7. The inkjet recording method according to claim 6, wherein thermal energy is applied to the ink to eject the ink droplets. 8. 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 the ink according to claim 1. unit. 9. The recording unit according to claim 8, wherein the head portion includes a head that applies thermal energy to the ink to eject ink droplets. 10. An ink cartridge comprising an ink containing portion containing ink, wherein the ink is
An ink cartridge, which is the ink described in 1. 11. The ink cartridge according to claim 10, wherein the ink containing portion has a liquid contact surface formed of polyolefin. 12. An ink according to claim 1, wherein the ink is an ink jet recording apparatus including a recording unit having an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets. An ink jet recording apparatus characterized by the above. 13. The head unit includes a head which causes thermal energy to act on ink to eject ink droplets.
2. The inkjet recording device according to 2. 14. The ink jet recording apparatus according to claim 12, wherein the ink containing portion is made of polyurethane. 15. A recording head for ejecting ink droplets,
The ink according to claim 1, wherein the ink is an ink cartridge having an ink containing portion containing ink, and an ink supply device for supplying the ink from the ink cartridge to a recording head. Characteristic inkjet recording device. 16. The ink jet recording apparatus according to claim 15, wherein the recording head is a head which causes thermal energy to act on ink to eject ink droplets. 17. The ink jet recording apparatus according to claim 15, wherein the ink containing portion has a liquid contact surface formed of polyolefin.