JPH01257059A - Liquid jet recording method - Google Patents

Abstract

PURPOSE:To type out a character at a high speed or to perform delicate gradation expression for bearing a vectorial color image, by a method wherein a function by which an almost uniform ink drop is formed and a gradation expression means by another means are established to one head. CONSTITUTION:Two heating elements 9, 9' capable of being individually driven are arranged having a far and near relation to an opening, and the heating element 9' near an orifice is established almost near an end surface of the orifice. When a command by which a thick density image of, for instance, a character or a solid image, etc., is typed out as image information comes, heat energy is given to the heat energy operation part 9 far from the opening to generate a bubble 11, and an ink drop is discharged. Then, when a command by which an image training delicate density variation, i.e. the image having gradation is typed out as image information comes, heat energy is given to the heat energy operation part 9' near the opening, an infinite number of fine ink drops 13 are generated, or come to be of atomized state and are jetted out form the opening.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid jet recording method, and more particularly to a bubble jet type ink jet recording method using thermal energy.

The non-impact recording method has recently attracted attention because the noise generated during recording is so small that it can be ignored. Among them, high-speed recording is possible,
However, the so-called inkjet recording method, which allows recording on plain paper without the need for special fixing treatment, is an extremely useful recording method, and various methods have been proposed and improvements have been made to improve the quality of products. Some have been developed, and efforts are still being made to put them into practical use.

Such an inkjet recording method involves jetting droplets of a recording liquid called ink.

Recording is performed by attaching the recording liquid to a recording member, and it is roughly divided into several methods depending on the method of generating recording liquid droplets and the control method for controlling the flight direction of the generated recording liquid droplets. Ru.

First, the first method is the one disclosed in, for example, U.S.P. 3060429 (Tale type 6 method), in which droplets of recording liquid are generated by electrostatic absorption), and the generated recording liquid droplets are Recording is performed by controlling an electric field in accordance with a recording signal to selectively attach recording liquid droplets onto a recording member.

To be more specific about this, an electric field is applied between the nozzle and the acceleration f11 pole to eject a negatively charged recording liquid droplet from the nozzle, and the ejected recording liquid droplet is used as a recording signal. Recording is performed by flying the droplet between x and y deflection electrodes that are configured to be electrically controllable according to the change in the electric field, and selectively depositing the droplet on the recording member by changing the intensity of the electric field.

The second method is described, for example, in USP 3596275, U
The method disclosed in SP 3298030 etc. (Swe
et method), in which droplets of recording liquid with a controlled amount of charge are generated by a continuous vibration generation method, and a --like electric field is applied to the generated droplets with a controlled amount of charge. Recording is performed on a recording member by flying between deflection electrodes.

Specifically, the orifice (discharge port) of a nozzle, which is a part of the recording head to which the piezo vibrating element is attached.
A charged electrode configured to have a recording signal applied thereto is arranged at a predetermined distance in front of the piezo vibrating element, and an electric signal of a constant frequency is applied to the piezo vibrating element to mechanically vibrate the piezo vibrating element, A small droplet of recording liquid is ejected from the ejection port. At this time, charges are electrostatically induced in the recording liquid droplet discharged by the charging electrode, and the droplet is charged with an amount of charge corresponding to the recording signal. When a small droplet of recording liquid with a controlled amount of charge flies between deflection electrodes to which a constant electric field is uniformly applied, it is deflected according to the amount of charge applied.
Only the droplets carrying the recording signal are allowed to deposit on the recording member.

The third method is, for example, the method disclosed in U.S.P. 3416153 (Hertz method), in which an electric field is applied between a nozzle and a ring-shaped charged electrode, and small droplets of recording liquid are generated by a continuous vibration generation method. This method records by atomizing it. That is, in this method, the atomization state of droplets is controlled by modulating the electric field intensity applied between the nozzle and the charging electrode in accordance with the recording signal, and the gradation of the recorded image is produced.

The fourth method is, for example, the method disclosed in USP 3747120 (Stemme method), and this method is fundamentally different in principle from the above three methods.

That is, in all three methods, the droplets of recording liquid ejected from the nozzle are electrically controlled while they are in flight, and the droplets carrying the recording signal are selectively attached to the recording member. In contrast, this Stemme method
Recording is performed by ejecting small droplets of recording liquid from an ejection port in response to a recording signal.

In other words, in the 5teIIIle method, an electrical recording signal is applied to a piezo vibrating element attached to a recording head that has an ejection port for discharging recording liquid, and this electrical recording signal is applied to the mechanical vibration of the piezo vibrating element. In this method, recording is performed by ejecting small droplets of recording liquid from the ejection opening according to the mechanical vibrations and adhering them to the recording member.

These four conventional methods each have their own advantages, but there are also points that can be solved in the other method.

That is, in the first to third methods, the direct energy for generating droplets of the recording liquid is electrical energy, and the deflection control of the droplets is also electric field control.

Therefore, although the first method is simple in structure, it requires a high voltage to generate droplets, and it is difficult to use a multi-nozzle recording head, making it unsuitable for high-speed recording.

The second method allows the recording head to have multiple nozzles and is suitable for high-speed recording, but it has a complicated structure, and the electrical control of recording liquid droplets is sophisticated and difficult, and satellite dots are placed on the recording member. There are problems such as easy occurrence of.

The third method has the advantage that images with excellent gradation can be recorded by atomizing recording liquid droplets, but on the other hand, it is difficult to control the atomization state.

There are various problems such as fogging in the recorded image, difficulty in forming a recording head with multiple nozzles, and unsuitability for high-speed recording.

The fourth method has relatively many advantages compared to the first to third methods. In other words, the structure is simple, and since recording is performed by ejecting recording liquid from the ejection opening of the nozzle on-demand, it is possible to reduce the number of small droplets that fly as in the first to third methods. Second, it is not necessary to collect droplets that are not needed to record an image, and unlike the first and second methods, there is no need to use a conductive recording liquid, and the material of the recording liquid is It has great advantages such as a high degree of freedom. On the other hand, on the other hand, it is difficult to make a recording head with multiple nozzles due to problems in processing the recording head, and it is extremely difficult to miniaturize a piezoelectric vibrating element having a desired resonance number. This method has disadvantages such as that it is not suitable for high-speed recording because the recording liquid droplets are ejected into flight using the mechanical energy of the mechanical vibration of the piezoelectric vibrating element.

Furthermore, Japanese Patent Application Laid-Open No. 48-9622 (the above-mentioned US P3
No. 747120) discloses, as a modification, the use of thermal energy instead of the mechanical vibration energy provided by means such as the piezo vibration element.

That is, the above-mentioned publication describes a so-called bubble jet liquid jet recording device that uses a heating coil that directly heats liquid as a pressure increasing means instead of a piezo vibrating element to generate steam that causes a pressure increase. There is.

However, in the above publication, the liquid ink in the bag-shaped ink chamber (liquid chamber), which has only one opening through which liquid ink can go in and out, is directly heated and vaporized by energizing the heating coil as a pressure increasing means. However, when discharging liquid continuously and repeatedly, it is not clear how to heat it.
There is nothing to suggest. In addition, the heating coil is located at the deepest part of the bag-shaped liquid chamber far from the liquid ink supply path, which makes the head structure complicated and requires continuous high-speed printing. For repeated use,
It is not suitable.

Moreover, with the technical content described in the above-mentioned publication, it is not possible to quickly prepare for the next liquid discharge after discharging the liquid using the generated heat, which is important in practice.

In this way, conventional methods have problems in terms of structure and high-speed recording.

The use of multi-nozzle recording heads has advantages and disadvantages in terms of the generation of satellite dots and fogging of recorded images, and there is a restriction that it can only be applied to applications that take advantage of these advantages.

In view of the above-mentioned points, the applicant first proposed a method that is structurally simple, facilitates multi-nozzle configuration, enables high-speed recording, does not generate satellite dots, and provides clear recording without fogging. proposed a liquid jet recording method that can obtain images (Japanese Patent Publication No. 56-9429), but this method generates bubbles in the ink and uses the force of the bubbles to eject ink droplets from an orifice. This is the basis of a jet-type inkjet recording device.

FIG. 17 is a diagram for explaining the operation of a bubble jet head as an example of an ink jet head to which the present invention is applied, FIG. 18 is a perspective view showing an example of a bubble jet head, and FIG. A lid substrate (FIG. 19(a)) and a heating element substrate (FIG. 19(a)) constituting the head shown in FIG.
The perspective view when disassembled in Figure (b)), Figure 20, is the 19th
This is a perspective view of the lid substrate shown in FIG.
4 is an orifice, 5 is a flow path, 6 is a region for forming a liquid chamber, 7 is an individual (independent) electrode, 8 is a common electrode, 9 is a heating element (heater), 10 is ink, 11 is a bubble, 12 is a flying ink droplet, and the present invention is applied to such a bubble jet type liquid jet recording head.

First, ink jetting by bubble jet will be explained with reference to FIG. 17. (a) is a steady state, and (b) is a heater in which the surface tension of the ink 10 and external pressure are in equilibrium on the orifice surface. 9 is heated until the surface temperature of the heater 9 rises rapidly and development occurs in the adjacent ink layer, resulting in a state where microbubbles 11 are scattered.

(c) shows a state in which the adjacent ink layer that is rapidly heated on the entire surface of the heater 9 instantaneously vaporizes to form a boiling film, and the bubbles 11 grow. At this time, the pressure inside the nozzle increases by the amount of bubble growth, and the balance with the external pressure on the orifice surface is lost, causing an ink column to begin to grow from the orifice.

(d) shows a state in which the bubble has grown to its maximum, and ink 10 corresponding to the volume of the bubble is pushed out from the orifice surface. At this time, no current is flowing through the heater 9, and the surface temperature of the heater 9 is decreasing. bubble 11
The maximum value of the volume of is slightly delayed from the timing of electric pulse application.

(e) shows a state in which the bubbles 11 are cooled by ink or the like and begin to contract. At the tip of the ink column, it moves forward while maintaining the extruded speed, and at the rear end, the ink flows backward from the orifice surface into the nozzle due to the decrease in nozzle internal pressure as the bubbles contract, creating a constriction in the ink column. .

In (f), the air bubbles 11 are further contracted, and the ink comes into contact with the heater surface, causing the heater surface to be cooled even more rapidly. At the orifice surface, the external pressure is higher than the nozzle internal pressure, so the meniscus is largely moving into the nozzle. The tip of the ink column becomes a droplet and drops 5 to 1 droplets toward the recording paper.
It is flying at a speed of 0m/SeC.

In (g), the air bubbles have completely disappeared in the process of refilling the orifice with ink by capillary action and returning to the state of (a).

While conducting many experiments based on the above-mentioned prior art, the present applicant discovered that while using a similar head configuration, the positional relationship between the opening (orifice) and the thermal energy acting part was slightly changed. By changing this, a recording method with a completely different principle from the conventional one was discovered, and based on this invention, a new recording method using a thermal energy acting part is provided.

A novel recording method using thermal energy according to the present invention includes: an opening for discharging droplets or spray; a thermal energy applying section for causing a state change in the recording liquid due to heat; A liquid jet recording comprising: a liquid chamber or flow path that communicates with each other, has the thermal energy acting portion as a part thereof, and holds the recording liquid therein; and means for supplying the recording liquid to the liquid chamber or flow path. In the head, the thermal energy acting section has two thermal energy acting sections that can be driven independently or that can independently transfer and receive energy, and the two thermal energy acting sections are arranged in a distance relationship with respect to the opening. , in a thermal energy acting part farther from the opening, generating bubbles by heat according to image information, and ejecting the recording liquid as droplets from the opening by the acting force accompanying the increase in the volume of the bubbles; Further, the thermal energy acting portion closer to the opening causes a state change in the recording liquid due to heat in accordance with image information, and causes a plurality of groups of fine droplets or spray to be ejected from the opening. It is characterized by being recorded by. Hereinafter, the present invention will be explained based on examples.

FIG. 2 is a main part configuration diagram for explaining the operating principle of the present invention.

A thermal energy applying section 9' is provided near the orifice with respect to the thermal energy applying section 9 of the conventional bubble jet type ink jet recording head shown in FIG. 17, and the thermal energy applying section is actuated in accordance with an image signal. As a result, instead of generating a single bubble and ejecting a single ink droplet, the ink heated by the heater 9' instantly boils or evaporates, resulting in a minute ink droplet 13 (normal bubble jet ink droplet). A plurality of particles (meaning smaller than a droplet) (or innumerable numbers, or in the form of a spray) are ejected from an orifice. Note that bubbles may be generated in the deep part of the flow path of the thermal energy acting part (on the opposite side from the orifice), as in conventional bubble jets, but this is not essential to this technology.

FIG. 1 is a configuration diagram of main parts for explaining one embodiment of the present invention, and FIG. 1(a) is a sectional view of the vicinity of the orifice of the head;
Figure (b) is a plan view of the vicinity of the head orifice (a diagram showing an example of the heating element electrode pattern). There are active parts 9,9', which are arranged in a distance relationship with respect to the opening. These two energy application parts 9.9' can be driven independently or can be independently given and received energy from the outside through the control electrode 7.7' and the common electrode 8, and can be used as needed. , or can be used depending on the image information. In addition, (c) is a diagram for explaining the operation when thermal energy is applied to the thermal energy acting part 9 that is farther from the orifice, and (d) is a diagram for explaining the operation when thermal energy is applied to the thermal energy acting part 9 that is closer to the orifice. This is a diagram to explain the operation when heat energy is applied to . As shown in the figure, thermal energy is applied to the thermal energy acting portion 9 far from the opening, and as is well known in the art, air bubbles 11 are generated, and the acting force causes ink droplets to be ejected. This is the same as 5 normal bubble jet technology. Next, when a command is received to print an image with subtle density changes, that is, an image with gradation, as image information, heat is applied to the thermal energy acting part 9' near the aperture, as shown in Figure (d). Energy is applied and, according to the principle shown in FIG. 2, countless minute ink droplets 13 are generated or sprayed and ejected from the opening. At this time, the thermal energy given to the thermal energy acting part can be changed to minute ink droplets, spray amount, or , the time during which they occur can be changed, thereby making it possible to record with varying densities on a recording medium (for example, paper).

Therefore, in the present invention, in the head shown in FIGS. 17 to 20, the heating resistor and electrode pattern are arranged as shown in FIG. 1(b), for example, but other modifications are possible. As such, a configuration as shown in FIG. 3 can also be considered. The important point is that the two heating elements 9,9', which can be driven independently, are arranged in a distance relationship with respect to the orifice. Also, the heating element 9' near the orifice is
is provided near the end face of the orifice.

FIG. 4 is a diagram showing a typical example for explaining the configuration of the main parts of the liquid jet recording head as described above, and FIG.
FIG. 4(b) is a detailed front partial view of the bubble jet recording head seen from the orifice side, and is a partial cross-sectional view taken along the line indicated by the dashed line XX in FIG. 4(a). .

The recording head 21 shown in these figures has a predetermined number of grooves of a predetermined width and depth at a predetermined linear density on a substrate 23 on which an electrothermal transducer 22 is provided on the back surface. A six-liquid discharge part 26 has a structure in which a liquid discharge part 26 including an orifice 25 for ejecting liquid is formed by bonding a grooved plate 24 so as to cover the substrate 23.
Thermal energy generated by the orifice 25 and the electrothermal converter 22 acts on the liquid to generate bubbles, causing a sudden change in state due to expansion and contraction of its volume, or causing a change in the state of the liquid due to heat. It has a heat acting part 27 where the heat is generated.

The heat action section 27 is located above the heat generation section 28 of the electrothermal converter 22, and has a heat action surface 29, which is a surface of the heat generation section 28 that comes into contact with the liquid, as its lower surface. The heat generating section 28 is
lower layer) C/I 30 provided on the base 23, the lower layer 3;
0 heating resistor JC431, the heating resistor/1
31 and an upper layer 32 provided on top of the top layer 31.

The heat generating resistance layer 31 includes the layers 1 to 31 in order to generate heat.
Electrodes 33 and 34 for energizing are provided on the surface thereof, and a heat generating portion 28 is formed by a heat generating resistor 7M between these electrodes.

The 'ltt electrode 33 is an electrode common to the heat generating part of each liquid discharge part, and the electrode 34 is a selection electrode for selectively generating heat in the heat generating part of each liquid discharge part. is provided along the liquid flow path.

The protective layer 32 is a heat generating resistor layer 31 in the heat generating section 28.
In order to chemically and physically protect the liquid from the liquid used, the heating resistor Ff431 and the liquid filling the liquid flow path of the liquid discharge part 26 are isolated.

Preventing a short circuit between the electrodes 33 and 34 through the liquid,
Furthermore, it has the role of preventing electrical leakage between adjacent electrodes.

The liquid flow paths provided in each liquid discharge part are communicated with each other via a common liquid chamber (not shown) that constitutes a part of the liquid flow path upstream of each liquid discharge part. Due to its design, the electrodes 33 and 34 connected to the electrothermal converter 22 provided in each liquid discharge section are protected by the upper layer and are connected to the bottom of the common liquid chamber on the upstream side of the heat acting section. It is set up to pass through.

FIG. 5 is a detailed diagram for explaining the structure of a thermal energy application section using a heating resistor. In the figure, 41 is a heating resistor, 42 is an electrode, 43 is a protective layer, and 44 is a power supply device.
Useful materials for forming the heating resistor 41 include, for example, a mixture of tantalum-8in, tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, hafnium, lanthanum, zirconium, titanium,
Examples include borides of metals such as tantalum, tungsten, molybdenum, niobium, chromium, and vanadium. Among the materials constituting these heating resistors 41, metal borides are particularly excellent, and among these, hafnium boride has the best properties, followed by zirconium boride.

The order is lanthanum boride, tantalum boride, vanadium boride, and niobium boride.

The heating resistor 41 can be formed using the above-mentioned materials using techniques such as electron beam evaporation and sputtering. The film thickness of the heating resistor 41 is determined according to its area, material, shape and size of the heat-acting part, and actual power consumption, etc. so that the amount of heat generated per unit time is as desired. However, in normal cases it is 0.001~
The thickness is 5 μm, preferably 0.01 to 1 μm.

As the material constituting the electrode 42, many commonly used electrode materials can be effectively used, and specifically,
For example, A1. A4. Examples include Au, Pt, Cu, etc., and these are used to provide a predetermined size, shape, and thickness at a predetermined position by a method such as vapor deposition.

The properties required of the protection fI 443 are that it protects the heat generating resistor 41 from the ink without hindering the effective transfer of the heat generated by the heat generating resistor 41 to the recording liquid (ink). . Examples of useful materials for forming the protective layer 43 include silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, and zirconium oxide. It can be formed using The thickness of the protective layer 43 is usually 0.01 to 10
pm, preferably Q, 1-5 pm, optimally 0.pm.
It is desirable that the thickness be 1 to 3 μm.

The present invention has been described above with reference to an example in which a heating resistor is used as a bubble generating means and a means for causing a state change in the recording liquid due to heat. It is also possible to use phenomena.

FIG. 6 is a diagram for explaining another means for generating bubbles in the recording liquid or causing a state change in the recording liquid due to heat. In the figure, 51 is a laser oscillator, 52 is an optical modulation Il!
? 53 is an optical modulator, 54 is a scanner, and 55 is a condensing lens. In the optical modulator 53, the laser light generated by the laser oscillator 51 is input to the optical modulator drive circuit g52 and electrically It is pulse-modulated according to the image information signal that is processed and output. The pulse-modulated laser beam passes through a scanner 54 and is focused by a condensing lens 55 on the outer wall of the thermal energy acting section, heating the outer wall 56 of the recording head and causing the inner recording liquid 57 to be heated. This causes bubbles to be generated and the state of the recording liquid to change due to heat.

Alternatively, the wall 56 of the thermal energy application section is made of a material that is transparent to the laser beam, and the laser beam is condensed by the condenser lens 55 so as to be focused on the recording liquid 57 inside, thereby directly heating the recording liquid. Alternatively, the recording liquid may be caused to undergo a state change due to heat.

FIG. 7 is a diagram for explaining an example of a printer using laser light as described above. This example shows an example in which the entire area (width) is covered.

Laser light emitted from the laser oscillator 51 is guided to the entrance aperture of the optical modulator 53. In the optical modulator 53, the laser beam undergoes intensity modulation according to the image information input signal to the optical modulator 53. The modulated laser beam passes through a reflecting mirror 5.
8 bends the optical path toward the beam expander 59 and enters the beam expander 59 . The beam expander 59 expands the beam diameter while remaining parallel light. Next, the laser beam with expanded beam diameter is
The light is incident on a rotating polygon mirror 60 that rotates at a constant high speed. The laser beam swept by the rotating polygonal rust 60 is imaged by the condenser lens 55 on the outer wall 56 of the thermal energy acting part of the drop generator or on the recording liquid inside. As a result, bubbles are generated in each thermal energy applying portion, or a state change due to heat occurs in the recording liquid, and recording droplets are ejected and recorded on the recording paper 62.

FIG. 8 is a diagram showing still another bubble generating means and means for causing a state change in the recording liquid due to heat, and this example shows the following:
A pair of discharge electrodes 70 arranged on the inner wall side of the thermal energy application section receive a high voltage pulse from a discharge device 71, causing discharge in the water, and the heat generated by the discharge instantly forms bubbles. The recording liquid is made to undergo a state change due to heat.

9 to 16 are diagrams showing specific examples of the discharge electrode shown in FIG. 8, respectively.

In the example shown in FIG. 9, the electrode 70 is shaped like a needle to concentrate the electric field and cause an efficient discharge (with low energy).

In the example shown in FIG. 10, two flat plate electrodes are used to stably generate bubbles between the electrodes or cause a state change in the recording liquid. Because of the needle-like electrode, the position of the generated bubbles or the state change of the recording liquid is stable.

The example shown in FIG. 11 is one in which the electrode has a substantially coaxial hole. Both holes of the two electrodes serve as guides, and the position of the generated bubbles or the state change of the recording liquid is further stabilized.

The example shown in FIG. 12 is a ring-shaped electrode, which is basically the same as the example shown in FIG. 11, and is a modified example thereof.

The example shown in FIG.

One is a ring-shaped electrode and the other is a needle-shaped electrode. The ring-shaped electrode aims to stabilize the generated bubbles, and the needle-shaped electrode aims to improve efficiency by concentrating the electric field.

In the example shown in FIG. 14, one ring-shaped electrode is formed on the wall surface of the thermal energy application section. In addition to the effects of the example shown in FIG. 13, this is aimed at ease of manufacturing by forming electrodes in a two-dimensional manner on the substrate. A plurality of such planar electrodes can be easily manufactured with high density by vapor deposition (or sputtering) or photoetching techniques. Particularly effective for multi-arrays.

In the example shown in FIG. 15, the ring-shaped electrode forming portion of the example shown in FIG. 14 is shaped along the outer periphery of the electrode and is raised one step higher than the surroundings. Again, this is aimed at stabilizing the state changes of the generated bubbles or the recording liquid, and is more stable than the one shown in FIG. 13 by adding a three-dimensional guide.

The example shown in FIG.

Contrary to the example shown in FIG. 15, the structure is such that the ring-shaped electrode forming part is sunk down from one periphery;
The generated bubbles or the state change of the recording liquid are stably formed.

The recording liquid used in the recording device according to the present invention is selected from the materials and the ratios of the composition components are adjusted so as to have the thermophysical properties and other physical properties described below, as well as those used in conventional recording methods. In addition to being chemically and physically stable like the recording liquid, it also has excellent responsiveness, fidelity, and thread-forming ability, does not harden in the liquid path, especially at the discharge port, and can flow in the flow path according to the recording speed. The physical properties are adjusted to give properties such as being able to circulate at a high speed, being quickly fixed on the recording member after recording, having sufficient recording density, and having a good shelf life.

The recording liquid used in the recording device according to the present invention is composed of a liquid medium, a recording agent for forming a recorded image, and an additive added to obtain desired characteristics. Depending on the type and composition ratio of additives, it is possible to obtain either aqueous, non-aqueous, soluble, electrically conductive, or insulating properties.

Liquid media are broadly classified into aqueous media and non-aqueous media, but the liquid media used are those that are combined with other selected constituents so that the recorded recording liquid has the above-mentioned physical properties. The combination is selected from the following.

Such non-aqueous media include, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 5ec-butyl alcohol, tart-butyl alcohol, isobutyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol. , C1-C10 alkyl alcohols such as octyl alcohol, nonyl alcohol, and decyl alcohol; For example, hydrocarbon solvents such as hexane, octane, cyclopentane, benzene, toluene, and quidylol; For example, carbon tetrachloride, trichloroethylene, and tetrachloride; Halogenated hydrocarbon solvents such as chloroethane and dichlorobenzene; Ether solvents such as ethyl ether, butyl ether, ethylene glycol diethyl ether, and ethylene glycol monoethyl ether; For example, acetone, methyl ethyl ketone, methyl propyl ketone, methyl amyl ketone, Ketone solvents such as cyclohexanone; ester solvents such as ethyl formate, methyl acetate, propyl acetate, phenyl acetate, and ethylene glycol monoethyl ether acetate; alcohol solvents such as diacetone alcohol;
Examples include petroleum-based hydrocarbon solvents.

These enumerated liquid media are appropriately selected and used so as to satisfy the compatibility with the recording agent and additives used and the various properties described below as a recording liquid. Within the range where a recording liquid having the characteristics can be prepared, two or more types may be mixed as necessary, or these non-aqueous media and water may be mixed within the above conditions. May be used.

Among the above-mentioned liquid media, water or water/alcohol-based liquid media are preferred in consideration of pollution, ease of availability, ease of preparation, and the like.

In addition to ensuring that the recording liquid to be prepared has the above-mentioned physical properties, the recording agent is also used to prevent sedimentation and agglomeration in liquid channels and recording liquid supply tanks due to long-term storage, as well as transport pipes and liquid channels. It is necessary to select and use materials in relation to the liquid medium and additives so as not to cause clogging. From this point of view, it is preferable to use a recording agent that is soluble in the liquid medium, but even if the recording agent is dispersible or poorly soluble in the liquid medium, the particles of the recording agent when dispersed in the liquid medium are It can be used if the diameter is made sufficiently small.

The recording material that can be used is appropriately selected depending on the recording member so as to fully suit the recording conditions. Recording agents include dyes and pigments.

The dyes used effectively are capable of satisfying the properties described below of the formulated recording liquid.

The recording liquid used in the recording device according to the present invention is selected from the materials and the ratios of the composition components are adjusted so as to have the thermophysical properties and other physical properties described below, as well as those used in conventional recording methods. In addition to being chemically and physically stable like the recording liquid, it also has excellent responsiveness, fidelity, and thread-forming ability, does not harden in the liquid path, especially at the discharge port, and can flow in the flow path according to the recording speed. The physical properties are adjusted to give properties such as being able to circulate at a high speed, being quickly fixed on the recording member after recording, having sufficient recording density, and having a good shelf life.

The recording liquid used in the recording device according to the present invention is composed of a liquid medium, a recording agent for forming a recorded image, and an additive added to obtain desired characteristics. Accordingly, by selecting the type and composition ratio of additives, it is possible to obtain any of aqueous, non-aqueous, 714M properties, conductivity, and insulating properties.

Liquid media are broadly classified into aqueous media and non-aqueous media, but the liquid media used are those that are combined with other selected constituents so that the recorded recording liquid has the above-mentioned physical properties. The combination is selected from the following.

Such non-aqueous media include, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 5ee-butyl alcohol, tart-butyl alcohol, isobutyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol. , octyl alcohol, nonyl alcohol, decyl alcohol, and other alkyl alcohols having 1 to 1 carbon atoms; For example, hydrocarbon solvents such as hexane, octane, cyclopentane, benzene, toluene, and quidylol; For example, carbon tetrachloride, trichloroethylene, and tetrachloride; Halogenated hydrocarbon solvents such as chloroethane and dichlorobenzene; Ether solvents such as ethyl ether, butyl ether, ethylene glycol diethyl ether, and ethylene glycol monoethyl ether; For example, acetone, methyl ethyl ketone, methyl propyl ketone, methyl amyl ketone, Ketone solvents such as cyclohexanone; ester solvents such as ethyl formate, methyl acetate, propyl acetate, phenyl acetate, and ethylene glycol monoethyl ether acetate; alcohol solvents such as diacetone alcohol;
Examples include petroleum-based hydrocarbon solvents.

These enumerated liquid media are appropriately selected and used so as to satisfy the compatibility with the recording agent and additives used and the various properties described below as a recording liquid. Two or more types may be mixed and used as appropriate within the range in which a recording liquid having the characteristics can be prepared. Moreover, these non-aqueous media and water may be mixed and used within the above conditions.

Among the above-mentioned liquid media, water or a water/alcohol-based liquid medium is preferred in consideration of the ease of manual labor and preparation.

In addition to ensuring that the recording liquid to be prepared has the above-mentioned physical properties, the recording agent is also used to prevent sedimentation and agglomeration in liquid channels and recording liquid supply tanks due to long-term storage, as well as transport pipes and liquid channels. It is necessary to select and use materials in relation to the liquid medium and additives so as not to cause clogging. From this point of view, it is preferable to use a recording agent that is soluble in the liquid medium, but even if the recording agent is dispersible or poorly soluble in the liquid medium, the particles of the recording agent when dispersed in the liquid medium are It can be used if the diameter is made sufficiently small.

The recording material that can be used is appropriately selected depending on the recording member so as to fully suit the recording conditions. Recording agents include dyes and pigments.

The dye that can be effectively used is one that satisfies the properties described below for the prepared recording liquid, and examples of suitable dyes include direct dyes as water-soluble dyes, basic dyes, and acidic dyes. Dyes, soluble vat dyes, acidic mordant dyes, mordant dyes, sulfur dyes as water-insoluble dyes, vat dyes, alcoholic dyes, oil-soluble dyes, disperse dyes, etc., as well as thren dyes, naphthol dyes, etc. Compatible dyes, chromium dyes, type 2 complex salt dyes,
It is selected from 1:1 type salt dyes, azoic dyes, cationic dyes, and the like.

Specifically, for example, Resolin Lil Blue PRL, Resolin Yellow PCG, Resolin Pink PRR, Resolin Green PB (manufactured by Bayer), and Sumikaron Blue 5.
-BG, Sumikaron Red E-EBL, Sumikalon Yellow E-4OL, Sumikalon Brilliant Blue S'-
BL (manufactured by Sumitomo Chemical), Diamond Mirror Yellow-HG
-8E, Diamond Thread BN-8E (manufactured by Mitsubishi Kasei), Kayalon Polyester Light Flavin 4GL
, Kayalon Polyester Blue-3R-8F, Kayalon Polyester Yellow YL-8E, Kaya Set Turquis Blue 776, Kaya Set Yellow 902, Kaya Set Red 026, Prodion Red H-2B, Prodion Blue H-3R (and above) Japanese bodywork), Revafix Golden Yellow P-R, Revafix Pril Red P
-B, Revafix Pril Orange P-OR (manufactured by Buyer), Sumifix Yellow GR5, Sumifix B, Sumifix Pril Red BS, Sumifix Pril Blue PB, Direct Black 40 (or Sumitomo Chemical R), Diamirror Brown 3G, Diamirror Yellow 〇, Diamirror Blue 3R, Diamirror Prill Blue B, Diamirror Prill Red BB (manufactured by Mitsubishi Kasei), Remazol Red B, Remazol Blue 3R, Remazol Yellow GNL, Remazol Prill Green 6B (manufactured by Hoechst), Cibacron Pril Yellow, Cibacron Pril Red 40E (manufactured by Ciba Geigy), Indico, Direct Tape Black E
-Ex, Diamine Black BH, Congo Red, Serious Black BH, Orange ■, Amido Black IO
B, Orange R○, Metaneil Yellow, Pictoria Scarlet, Nigrosine, Diamond Black PBB
(manufactured by Egame), Diacit Blue 3G, Diacit Fast Green GW, Diacito Milling Navy Blue R, Indanthrene (manufactured by Mitsubishi Kasei)
, Zapon-dye (BASFI).

Orazole dye made by CCI B A), Lanasin dye (made by CCI BA),
The above-mentioned physical property values are given to the recording liquid to be prepared from among the following: (manufactured by Mitsubishi Kasei), Diacrylic Orange RL-E, Diacrylic Brilliant Blue 2B-E, Diacrylic Turquis Blue BG-E (manufactured by Mitsubishi Kasei), etc. Those that can be used are preferably used.

These dyes are appropriately selected as desired and used after being dissolved or dispersed in the liquid medium used.

As pigments that can be effectively used, many of inorganic pigments and organic pigments are suitably used. Specific examples of such pigments include inorganic pigments such as cadmium sulfide, sulfur, selenium, zinc sulfide, cadmium sulfoselenide, yellow lead, zinc chromate, molybdenum red, Guinée green, titanium white, zinc white, and zinc white. Handle, chromium oxide green, red lead, cobalt acid, barium titanate, titanium yellow, iron black, navy blue, litharge, cadmium red, silver sulfide, lead sulfate, barium sulfate, ultramarine blue, calcium carbonate, magnesium carbonate, lead white, Examples include cobalt violet, cobalt blue, emerald green, and carbon black.

Most of the organic pigments are classified as dyes and often overlap with dyes, but specifically, the following are preferably used.

(a) Insoluble azo type (naphthol type) Brilliant Carmine BS, Lake Carmine FB, Brilliant Fast Scarlet, Lake Red 4R, Para Red, Permanent Red R, Fast Red FO
R, Lake Bordeaux 5B, Vermilion N011, Vermilion NO.2, Toluidine Maroon.

(b) Insoluble azo type (anilide type) Diazo Yellow, Fast Yellow G, Fast Yellow 10G, Diazo Orange, Palkan Orange, Balazolone Red.

(c) Soluble Azo Lake Orange, Brilliant Carmine 3B, Brilliant Carmine 6B, Brilliant Scarlet G, Lake Red C, Lake Red D, Lake Red R, Watching Red, Lake Bordeaux 10B, Bon Maroon L
, Bonmaroon M.

(d) Phthalocyanine-based phthalocyanine blue, fast sky blue, and phthalocyanine green.

(e) Dyeing Lake Yellow Lake, Eosin Lake, Rose Lake, Violet Lake, Blue Lake, Green Lake, Sepia Lake.

(f) Mordant system Alizarin Lake, Madakamine.

(g) Vat-dyed type Industhrene series, Fast Blue Lake (GGS).

(h) Basic dye lake system Rhodamine Lake, Malachite Green Lake.

(i) Acid dye lake type Fast Sky Blue, Quinoline Yellow Lake, Quinacridone type, Dioxazine type.

The quantitative relationship between the liquid medium and the recording agent is determined based on conditions such as clogging of the liquid path, drying of the recording liquid in the liquid path, bleeding when applied to the recording member, and drying speed in addition to the formulation. The recording agent is usually 1 to 50 parts by weight, preferably 3 parts by weight, based on 100 parts of the liquid medium.
~30 parts, optimally 5 to 10 parts.

When the recording liquid is a dispersion system (a system in which the recording agent is dispersed in a liquid medium), the particle size of the dispersed recording agent depends on the type of recording agent, recording conditions, inner diameter of the liquid path, ejection opening diameter, and recording member. It is determined as desired depending on the type of recording agent, but if the particle size is too large, sedimentation of the recording agent particles may occur during storage, resulting in uneven density or clogging of the liquid path. This is undesirable because it may cause density unevenness in the recorded image.

Taking this into consideration, the particle size of the recording agent used as a dispersion recording liquid is usually 0.01 to 30μ, preferably 0.01 to 20μ, and optimally 0.01 to 8μ. It is desirable to Furthermore, the particle size distribution of the dispersed recording agent is preferably as narrow as possible, and is usually D±3μ,
The preferred value is D+1.5μ (where D represents the average particle size).

Examples of additives used include viscosity modifiers, surface tension modifiers, pHJ modifiers, resistivity modifiers, wetting agents, and infrared absorbing exothermic agents.

In addition to obtaining the above-mentioned physical property values, the viscosity modifier and surface tension mvm agent must be able to flow through the liquid path at a sufficient flow rate depending on the recording speed, and prevent the recording liquid from going around at the discharge port of the liquid path. Things that can be prevented, bleeding when applied to recording materials (
It is added to prevent the spread of spot diameter.

The viscosity modifier and surface tension modifier are selected from commonly known agents as long as they are effective and do not adversely affect the liquid medium and recording material used, so as to satisfy the desired properties. used.

Specifically, viscosity modifiers include polyvinyl alcohol, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, water-soluble acrylic resin, polyvinyl pyrrolidone,
Gum arabic starch and the like can be exemplified as suitable examples.

Surface tension modifiers that are suitably selected and used as desired include anionic, cationic, and nonionic surfactants, and specifically, as anionic surfactants, polyethylene glycol ether sulfate, polyethylene glycol ether sulfate, Ester salts, etc., cationic types such as poly2-vinylpyridine derivatives, poly4-vinylpyridine derivatives, etc., nonionic types such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan monoalkyl Examples include ester, polyoxyethylene alkylamine, and the like.

In addition to these surfactants, there are also amino acids such as jetanolamine, propatoolamine, and morpholinic acid, basic substances such as ammonium hydroxide and sodium hydroxide, and substituted pyrrolidones such as N-methyl-2-pyrrolidone. Used effectively.

These surface tension modifiers do not adversely affect each other or other constituents, and provide the above-mentioned physical properties to the recording liquid being formulated, so that a recording liquid having a desired value of surface tension is formulated. If necessary, two or more types may be mixed and used within the range specified above.

The amount of these surface tension modifiers to be added is determined as appropriate depending on the type, other constituent components of the recording liquid to be prepared, and desired recording characteristics. Usually 0.0001 to 0.1 parts by weight, preferably 0.0001 to 0.1 parts by weight.
The amount is desirably 0.001 to 0.01 parts by weight.

The pH adjuster is used to maintain a predetermined pH value in order to maintain the chemical stability of the prepared recording liquid, for example, to prevent changes in physical properties due to long-term storage and to prevent sedimentation and aggregation of the recording agent and other components. It is added at the right time and in an appropriate amount within a range that does not deviate from the physical property values.

As the pH adjuster suitably used in the present invention,
Almost any pH can be used as long as it can control the pH value to a desired level without adversely affecting the recording liquid being prepared.

Specific examples of such pH adjusters include lower alkanolamines, monovalent hydroxides such as alkali metal hydroxides, and ammonium hydroxide.

These pH adjusters are added in a necessary amount so that the recording liquid to be prepared has a desired pH value within a range that does not deviate from the above-mentioned physical property values.

The lubricant to be used is one that is more effective than those commonly known in the technical field related to the present invention, especially one that is thermally stable, as long as the recording liquid to be prepared does not deviate from the various physical properties listed below. are preferably used. Specific examples of such lubricants include polyalkylene glycols such as polyethylene glycol and polypropylene glycol; alkylene glycols in which the alkylene group has 2 to 6 carbon atoms such as butylene glycol and hexylene glycol; for example, ethylene glycol; Lower alkyl ethers of diethylene glycol such as methyl ether, diethylene glycol methyl ether, and diethylene glycol ethyl ether; Glycerin; Lower alcohol oxytriglycols such as methoxytriglycol and ethoxytriglycol; N-vinyl-2-
Examples include pyrrolidone oligomer; and the like.

These lubricants are added in the required amount as desired so that the recording liquid satisfies the desired characteristics.
The amount added is usually 0.1 to 1% based on the total weight of the recording liquid.
0wt%, preferably 0.1-8vt%, optimally 0.2
It is desirable to set it to ~7vt%.

In addition to being used alone, the above lubricants may be used in combination of two or more types provided that they do not adversely affect each other.

The recording liquid used in the recording device of the present invention may be added with the above-mentioned additives in required amounts as desired. For example, alkyd resin,
Resin polymers such as acrylic resin, acrylamide resin, polyvinyl alcohol, and polyvinylpyrrolidone may be added.

The recording liquid used in the recording device of the present invention has specific heat, coefficient of thermal expansion, thermal conductivity, viscosity, surface tension, pH, and charged recording droplets so as to have the various recording properties described above. In the case of recording, it is desirable that the composition be prepared so that the characteristic values such as specific resistance are within the conditional range of the characteristic.

That is, these characteristics have important relationships with the stability of the stringing phenomenon, responsiveness and fidelity to thermal energy effects, image density, chemical stability, fluidity within the liquid path, etc. Therefore, in the present invention, it is necessary to pay sufficient attention to these matters when preparing the recording liquid.

It is desirable that the above-mentioned properties of the recording liquid that can be effectively used in the recording device of the present invention be as shown in Table 1 below. It is not necessary to satisfy the numerical conditions shown, and it is sufficient that some of these physical properties take values that satisfy the conditions in Table 1, depending on the required recording characteristics. It is desirable that the specific heat, thermal expansion coefficient, thermal conductivity, viscosity, and surface tension be defined by the values shown in Table 1. Of course, it goes without saying that the more of the above-mentioned properties of the prepared recording liquid that satisfy the values shown in Table 1, the better the recording will be.

Effects in Table 1 As is clear from the above description, according to the present invention, one head (ink ejection unit) has the function of forming substantially uniform ink droplets using the normal baffle jet method, that is, the function of forming substantially uniform ink droplets.
By providing gradation expression means by other means, you can use them properly to create characters at high speed (
Mainly uses the normal bubble jet technology), and performs delicate gradation expression for Victorian color images (normal bubble jet technology is used for dark areas, and fine ink is used for shading. It has the advantage that it can be used (using drops or spray).

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts for explaining an embodiment of the present invention, FIG. 2 is a diagram for explaining the operating principle of the present invention,
FIG. 3 is a diagram showing an example of a modified arrangement of the 4-pole pattern used in the implementation of the present invention, and FIGS. 4 and 5 illustrate an example in which a heating resistor is used as a thermal energy supply means. Figures 6 and 7 are diagrams for explaining an example in which a pulse laser is used as a thermal energy supply means, and Figures 8 to 16 are diagrams for explaining an example in which a discharge phenomenon is used. FIGS. 17 to 20, which are diagrams for explaining an example, are diagrams for explaining the operation of a bubble jet type inkjet recording head using a heating resistor. 1.2...Substrate, 7,7'...Control electrode, 8...
Common electrode, 9, 9'... Heat generating resistor, 1o... Ink, 11... Air bubble, 12... Ink droplet, 13...
Atomized ink drops.

Claims (1)

[Claims] 1. An opening for discharging droplets or spray, a thermal energy acting part for causing a state change in the recording liquid due to heat, communicating with the opening and having the thermal energy acting part as a part thereof; In a liquid jet recording head having a liquid chamber or flow path for holding a recording liquid therein, and a means for supplying the recording liquid to the liquid chamber or flow path, the thermal energy application section can be independently driven or is independent. has two thermal energy acting parts that can transfer energy to and from each other, the two thermal energy acting parts are arranged in a distance relationship with respect to the opening, and the thermal energy acting part that is farther from the opening has: Bubbles are generated by heat according to the image information, and the recording liquid is ejected as droplets from the opening by the acting force accompanying the increase in the volume of the bubbles, and the thermal energy acting portion near the opening is . A liquid jet recording method, characterized in that recording is performed by causing a state change in the recording liquid due to heat in accordance with image information and ejecting a plurality of groups of minute droplets or spray from the opening.