JPH04202574A - Ink, method for ink jet recording using the same and apparatus using the same ink - Google Patents

Abstract

PURPOSE:To obtain the subject ink for ink jet recording methods, containing a recording agent, N-acetylethanolamine and a liquid medium and capable of providing printed matters without causing a viscosity change of the ink on an orifice surface and any dot disturbance even if there is a nozzle having a dwell time of discharge. CONSTITUTION:The objective ink containing a recording agent, a liquid medium capable of dissolving or dispersing the-aforementioned recording agent and preferably 1-5wt.% N-acetylethanolamine.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an ink, an inkjet recording method using the ink, and a device using such an ink. The present invention also relates to an ink, an inkjet recording method, a recording unit, an inkjet recording apparatus, and an ink cartridge that can perform high-definition and high-quality recording without causing disturbance in the ejection direction.

(Prior Art) Conventionally, inkjet inks with a wide variety of compositions have been reported. In recent years, ink composition and physical properties have been developed to enable good recording even on plain papers commonly used in offices, such as copy paper, report paper, notebooks, stationery, bond paper, and continuous slip paper. Detailed research and development is being carried out from various aspects such as:

For example, ink generally contains high boiling point organic solvents such as glycol for the purpose of preventing drying and clogging, but when printing on various recording materials using such ink, When printing is paused for a certain period of time, when printing resumes and the nozzle receives the next signal, the viscosity of the ink often changes due to evaporation of liquid medium components at the orifice during the pause, and in this case, the There is a problem in that disturbances occur and print quality deteriorates.

(Problem to be Solved by the Invention) Therefore, an object of the present invention is to enable high-quality printing without disturbing the ink ejection direction when printing is resumed even if printing is stopped for a certain period of time during printing. An object of the present invention is to provide an ink, an inkjet recording method using the ink, and a device using the ink.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides an ink containing a recording agent and a liquid medium for dissolving or dispersing the recording agent, which is characterized by containing N-acetylethanolamine, an inkjet recording method using the same, and an inkjet recording method using such an ink. It is a device.

(Function) By adding a specific compound to the ink, even if printing is stopped for a certain period of time in the middle of printing, there is no disturbance in the direction of ink ejection when printing resumes, making it possible to produce high-quality printing. , an inkjet recording method using this ink, and a device using such an ink can be provided.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The specific compounds used in the present invention and which mainly characterize the present invention are known per se, and can be obtained from the market and used easily.

The amount of the specific compound added to the ink varies depending on the pigment used and other liquid medium components used together, but preferably accounts for 1 to 5% by weight in the ink.

The ink of the present invention is characterized by containing the above-mentioned specific compound together with the pigment, but it can also be used in combination with water and other organic solvents that have been used in conventionally known inks. For example, as an organic solvent, , C1-5 alkyl alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 5ec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol, or these. Halogenated derivatives of; amides such as dimethylformamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol , oxyethylene or oxypropylene addition polymers such as polyethylene glycol and polypropylene glycol:
Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, 1,2,6-hexanetriol, hexylene glycol; thiodiglycol; glycerin: ethylene Lower alkyl ethers of polyhydric alcohols such as glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; triethylene glycol dimethyl (or ethyl) ether, tetraethylene glycol dimethyl Lower dialkyl ethers of polyhydric alcohols such as (or ethyl) ether: sulfolane, N-methyl-2-pyrrolidone, 2-pyrrolidone, 1
, 3-dimethyl-2-imidazolidinone and the like.

The content of the water-soluble organic solvent is generally 2% to 50% by weight, preferably 2% to 3% by weight based on the total weight of the ink.
The range is 0%.

Although the above-mentioned media can be used alone or in mixtures, the most preferred liquid media composition consists of water and one or more organic solvents, with a small amount of the solvent (both containing one or more water-soluble high-boiling organic solvents, e.g. , polyhydric alcohols such as diethylene glycol, triethylene glycol, glycerin, 1,2.6-hexanetriol and thiodiglycol, and 2-pyrrolidone.

The pigments constituting the ink of the present invention include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes,
Vat dyes, soluble architectural dyes, reactive disperse dyes, oil dyes,
Various pigments may be used, but water-soluble dyes are particularly preferred from the viewpoint of ink performance.

The content of these pigments is determined depending on the type of liquid medium components, the characteristics required of the ink, etc., but numerically it is about 0.2 to 20% by weight in the total amount of ink, preferably 0.
The proportion is 5 to 10%, more preferably 1 to 5%.

The main components of the ink of the present invention are as described above, but various other dispersants, surfactants, viscosity modifiers, surface tension modifiers, fluorescent brighteners, etc. may be added within the range that does not impede the achievement of the purpose of the present invention. It can be added as needed.

For example, viscosity modifiers such as polyvinyl alcohol, celluloses, and water-soluble resins; various cationic, anionic, or nonionic surfactants; surface tension modifiers such as jetanolamine and triethanolamine; pH modifiers using buffers; Antifungal agents and the like can be mentioned.

In addition, in order to prepare ink used in inkjet recording methods that charge the ink, lithium chloride,
A resistivity adjuster such as inorganic salts such as ammonium chloride and sodium chloride is added.

The ink of the present invention is particularly suitable when applied to an inkjet recording method in which ink is ejected by a bubbling phenomenon of the ink caused by thermal energy, and the ink is said to be extremely stable in ejection and free from the generation of satellite dots. It has characteristics. However, in this case, the thermal physical 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 when recording on plain paper, dryness, and permeability of recorded materials, and at the same time improves the physical properties of the ink itself in order to improve matching to the recording head. It is desirable that the surface tension at 25°C be adjusted to 30 to 68 dyne/cm and the viscosity adjusted to 15 cP or less, preferably 10 cP or less, more preferably 5 cP or less.

Therefore, in order to adjust the ink to the above-mentioned physical properties and solve the problems with plain paper, the amount of water contained in the ink of the present invention should be 50% by weight or more, preferably 60% by weight or more. suitable.

The ink of the present invention is particularly suitable for use in an inkjet recording method in which recording is performed by ejecting droplets under the action of thermal energy, but it goes without saying that it can also be used for general writing instruments.

A preferred method and apparatus for recording using the ink of the present invention is a method and apparatus that applies thermal energy corresponding to a recording signal to the ink in the chamber of a recording head and generates droplets using the thermal energy. Can be mentioned.

Examples of the configuration of the head, which is the main part of the device, are shown in FIGS. 1(a), 1(b), and 2.

The head 13 is made by bonding a glass, ceramic, or plastic plate, etc., having grooves 14 through which ink passes, and a heat-generating head 15 (the head is shown in the figure, but is not limited thereto) used for thermal recording. It can be obtained by

The heat generating head 15 has a protective film 1 formed of silicon oxide or the like.
6. It consists of aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate 20 with good heat dissipation properties such as alumina.

The ink 21 has reached a discharge orifice (micropore) 22, and a meniscus 23 is formed 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 suddenly generates heat, bubbles are generated in the ink 21 in contact with this area, and the pressure causes a meniscus. 23 is a protruding taste ink 21 is ejected, becomes a recording droplet 24 from an orifice 22, and flies toward a recording material 25.

FIG. 2 shows an external view of the multi-head shown in FIG. 1(a) in which a large number of heads and ends are arranged. The mulch head is manufactured by closely adhering a glass plate 27 having a mulch groove 26 and a heat generating head 28 similar to that explained in FIG. 1(a).

In addition, FIG. 1(a) shows the direction along the ink flow path.
FIG. 1(b) is a sectional view taken along A-B in FIG. 1(a).
This is a cut plane along a line.

FIG. 3 shows an example of an ink jet recording apparatus incorporating such a head.

In FIG. 3, 61 is a blade as a wiping member, one end of which is held by a blade holding member and becomes a fixed end, forming a cantilever (-) shape. The blade 61 is positioned adjacent to the recording area by the recording head. Also, in this example, it is held in a protruding form in the moving path of the recording head. 62 is a cap, which is disposed at a home position adjacent to the blade 61 and is aligned with the moving direction of the recording head. It has a structure that moves in the vertical direction and comes into contact with the ejection orifice surface to perform capping.Furthermore, 63 is an ink absorber provided adjacent to the blade 61, and like the blade 61, the ink absorber 63 is attached to the recording/distribution path. The blade 61, the cap 62, and the absorber 63 constitute a discharge recovery section 64.
The blade 61 and the absorber 63 remove moisture, dust, etc. from the ink ejection orifice surface.

Reference numeral 65 is a recording head that has an ejection energy generating means and performs recording by ejecting ink onto a recording material facing the ejection orifice surface on which ejection ports are arranged, and 66 is a recording head that mounts the print head 65 and moves the print head 65. It is a carriage for carrying out. The carriage 66 is slidably engaged with a guide shaft 67, and a portion of the carriage 66 is connected to a belt 6 driven by a motor 68.
9 (not shown). As a result, carriage 6
6 can be moved 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 feeder for inserting 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 as recording progresses, the recording material is discharged to a paper discharge section provided with a paper discharge roller 53.

In the above configuration, 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 moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection port surface of the recording head 65 is wiped. Note that when the cap 62 contacts the ejection surface of the recording head 65 to perform capping, 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 tray 1 are in the same position as in the above-mentioned wiping. As a result,
During this movement as well, the ejection orifice surface of the recording head 65 is wiped.

The above-mentioned movement of the print head to the home position is not limited to the end of printing or recovery of ejection, but also the movement of the print head to the home position adjacent to the print area at predetermined intervals while the print head moves across the print area for printing. However, along with this movement, the above-mentioned wiping is performed.

FIG. 4 is a diagram showing an example of an ink cartridge containing ink supplied to the head via an ink supply member, for example, a tube. Here, 40 is an ink storage section, for example, an ink bag, which stores ink for supply, and a rubber stopper 42 is provided at the tip thereof. This stopper 42
By inserting a needle (not shown) into the ink bag 40, the ink in the ink bag 40 can be supplied to the head. 44 is an ink absorber that receives waste ink.

For the present invention, it is preferable for the ink storage part to have a surface in contact with the ink made of polyolefin, particularly polyethylene.

The inkjet recording device used in the present invention includes:
It can be suitably used not only in the case where the head and ink cartridge are separate bodies as described above, but also in one in which they are integrated as shown in FIG.

In FIG. 5, reference numeral 70 denotes a recording unit, in which an ink containing part containing ink, for example, an ink absorber, is housed, and the ink in the ink absorber passes through a head having a plurality of orifices. The ink droplets are ejected from the portion 71 as ink droplets. For the present invention, it is preferable to use polyurethane as the material for the ink absorber.

Reference numeral 72 denotes an atmosphere ventilation port for communicating the inside of the cartridge with the atmosphere.

This recording unit 70 is used in place of the recording head shown in FIG. 3, and is detachable from the carriage 66.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. In the text, parts and percentages are based on weight unless otherwise specified.

Examples 1 to 5 and Comparative Examples 1 to 3 The following components were mixed and dissolved, and filtered under pressure using a filter with a pore size of 1 μm to obtain inks of the present invention and inks of comparative examples shown in Table 1 below.

Pure water 62 parts Diethylene glycol 30 parts C,1, Direct Black 51 3 parts N-acetylethanolamine 5 parts 5 gal Pure water 63 parts Ethylene glycol monomethyl ether 20 parts C,1, Direct Black 154 4 parts N-acetyl ethanol Amine 3 parts pure water 61 parts Polyethylene glycol 300 15 parts N, N-dimethylimidazolidinone 15 parts C,1, Direct Black 169 4 parts N-acetylethanolamine 5 parts pure water 77 parts Diethylene glycol 15 parts C,1, Direct Black 51 3 parts N-acetylethanolamine 5 parts Impure ■ 5 pure water 80 parts Glycerin 5 parts Thiodiglycol
5 parts isopropyl alcohol
Part 2 C, 1, Direct Black 15
4 3 parts N-acetylethanolamine
5 parts, 1 part pure water 67 parts diethylene glycol 30 parts C, 1, Direct Black 51 3 parts ratio 1 stone 1 milk Pure water 66 parts ethylene glycol monomethyl ether 20 parts N-methyl-
2-Pyrrolidone 10 parts C, I Direct Black 154 4 parts Polyethylene Glycol 300 15 parts N, N-
Dimethylimidazolidinone 15 parts C1, Direct Black 169 4 parts Next, using the above ink, an on-demand type multi-head ( Discharge orifice diameter 25 μm, resistance value of heating resistor 120 ohm, drive voltage 30 volts, frequency 4K
The ejection stability was investigated when intermittent ejection was performed at an environmental temperature of 20° C. and humidity of 45% using a recording apparatus having a high frequency (Hz). That is, when operating in the mode of (1) continuous ejection for 10 seconds → (2) pause for a certain period of time → (3) continuous ejection, (3) When re-discharging, the initial print may be disturbed, but this depends on the pause time in (2), so measure the time when the print disorder starts when the pause time is extended step by step. The effects of the inks of the present invention and comparative examples were evaluated. The evaluation results are shown in Table 2 below.

Example 1 150 Example 2 160 Example 3
180 Example 4
110 Example 5
110 Comparative Example 1
45 Comparative Example 2 60
Comparative Example 3 40 Usage Examples Using each of the above inks, an inkjet printer BJ-130 (trade name) was used at an environmental temperature of 200C and a humidity of 4.
When printing a document at 5%, the inks of Examples 1 to 5 all produced stable printing with no disturbances, but the inks of Comparative Examples often showed irregularities during printing. Disturbances occurred and the printed matter was of low quality.

(Effects) As is clear from the above explanation, according to the present invention, even if some documents have nozzles that have a pause in ejection during printing, the ink can be discharged on the orifice surface during that time. Since no viscosity change occurs and ink droplets can be normally ejected in response to the next signal, high-quality printed matter without dot disturbances can be obtained.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are a longitudinal sectional view and a transverse sectional view of a head section of an inkjet recording apparatus. FIG. 2 is an external perspective view of a multi-head head shown in FIG. 1. FIG. 3 is a perspective view showing an example of an inkjet recording device. FIG. 4 is a longitudinal sectional view of the ink cartridge. FIG. 5 is a perspective view of the recording unit. 61: Wiping member 62: Cap 63: Ink absorber 64: Ejection recovery section 65: Recording head 66: Carriage Patent applicant Canon Corporation 9? i,, ;i Figure 1 (a) B Figure 1 (b) Figure 2 Figure 3

Claims (11)

[Claims] (1) An ink containing a recording agent and a liquid medium for dissolving or dispersing the same, characterized by containing N-acetylethanolamine. (2) The ink according to claim 1, wherein the content of N-acetylethanolamine is in the range of 1 to 5% by weight based on the total weight of the ink. (3) An inkjet recording method in which recording is performed by ejecting ink droplets from an orifice according to a recording signal, wherein the ink is the ink according to claim 1. (4) The inkjet recording method according to claim 3, wherein ink droplets are ejected by applying thermal energy to the ink. (5) A recording unit comprising an ink storage section containing ink and a head section for ejecting the ink as ink droplets, wherein the ink is the ink according to claim 1. (6) The recording unit according to claim 5, wherein the head section is a head that applies thermal energy to ink to eject ink droplets. (7) An ink cartridge comprising an ink storage portion containing ink, wherein the ink is the ink according to claim 1. (8) In an inkjet recording apparatus including an ink storage unit containing ink and a recording unit having a head unit for ejecting the ink as ink droplets, the ink is the ink according to claim 1. Features of inkjet recording device. (9) The inkjet recording apparatus according to claim 8, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets. (10) In an inkjet recording apparatus comprising a recording head for ejecting ink droplets, an ink cartridge having an ink storage section containing ink, and an ink supply section for supplying ink from the ink cartridge to the recording head, An inkjet recording apparatus characterized in that the ink is the ink according to claim 1. (11) The inkjet recording apparatus according to claim 10, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets.