JPH01258979A - Liquid jet recording method - Google Patents

Abstract

PURPOSE:To enable a recording in a drive frequency range not less than 3kHz, by incorporating a foaming stabilizer, such as glyceline, ethanol, isopropyl alcohol, and butanol, in an aqueous recording liquid in a predetermined ratio. CONSTITUTION:In an aqueous recording liquid, at least one type of solvent selected from among groups made of 10% or more glyceline, 10% or more methanol, 5% or more ethanol, 3% or more isopropyl alcohol, and 1% or more butanol in weight ratio, is incorporated as a foaming stabilizer to inhibit a foaming fluctuation, i.e. a liquid drip discharge speed fluctuation, in a high frequency range. Then, when a recording liquid is discharged from an orifice 2a into a liquid flow path 2b as a liquid drip by driving a heating resistor 3 and forming a bubble 8 on a protective layer 6, even in the drive in a high-frequency range not less than 3kHz the bubble can be formed with a stable bubble length L, and a target point accuracy and a dispersion in dot diameter are improved. In this manner, an unsatisfactory printing due to non-discharge in a high-frequency range can be prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a liquid jet recording method, and more specifically, by incorporating a foaming stabilizer into the recording liquid used for recording, jetting stability in a high frequency range can be improved. The present invention relates to a liquid jet recording method that is inexpensive, high speed, and highly reliable.

(Prior art) The liquid jet recording method is capable of high-speed recording in that the noise generated during recording is extremely small to the extent that it can be ignored.Furthermore, it can be fixed on so-called plain paper, so it requires no special treatment for the recording material. It has the advantage of being able to record without the need for processing, and has recently attracted attention.

Among them, for example, the liquid jet recording method described in Japanese Patent Application Laid-Open No. 54-51837 and German Opening Publication (DOLS) No. 2843064 applies thermal energy to the liquid to generate a driving force for ejecting droplets. This method has a different feature from other liquid jet recording methods in that it obtains the following.

That is, in the recording method disclosed in the above-mentioned publication, the liquid subjected to the action of thermal energy undergoes a state change accompanied by a sharp increase in volume, and the acting force based on the state change causes the liquid to be released from the orifice at the tip of the recording head. It is characterized in that liquid is ejected to form flying droplets, and the droplets adhere to a recording member to perform recording.

In particular, the liquid jet recording method disclosed in DOL5 2843064 is a so-called drop-and-de
Not only can it be applied extremely effectively to the mand recording method, but it can also easily realize a recording head with a full 1ine type recording head and high-density multi-orifice, allowing high-resolution and high-quality images to be obtained at high speed. It has the characteristic of being

FIG. 1 shows a schematic perspective view of a conventional liquid jet recording head.

The substrate portion l of the recording head of the apparatus applied to the above recording method communicates with an orifice 2a provided for ejecting liquid, and thermal energy for ejecting droplets acts on the liquid. It includes a liquid discharge part having a liquid flow path 2b of which a heat acting part 3 is a part of the structure, and an electrothermal converter as a means for generating thermal energy.

This electrothermal converter includes a pair of electrodes and a heat generating resistor layer connected to these electrodes and defining a heat generating region (heat generating portion) between these electrodes.

Furthermore, a common liquid chamber 4 for supplying the recording liquid to each flow path, and a supply [15 for supplying the common liquid chamber to the common liquid chamber,
It communicates with a recording liquid storage chamber outside the head via a tube.

Recording fluids that contain water as their main component are often used to compensate for the poor absorption and drying properties of plain paper (paper commonly used in offices, such as copy paper, notebook report paper, etc.). .

(Problems to be Solved by the Invention) Incidentally, in order to record high-quality images at high speed, it is said that a nozzle density of 300 dpi (dots/1 nch) or more is required. When printing with such a nozzle density, it is obvious that the distance between the dots becomes narrow, so that the positional deviation of the dots, that is, the landing accuracy of the dots becomes a problem. This landing accuracy is caused by fluctuations in the velocity of ejected droplets caused by instability of foaming in the ink jet recording method using thermal energy according to the present invention. Furthermore, in extreme cases, a lack of recording may occur due to a non-ejection phenomenon.

In addition, in order to achieve high-speed recording, especially in serial type printers, a driving frequency corresponding to the nozzle density is required. For example, at 300 dpi, the driving frequency is 3KH.
z or higher and 360 dpi requires a driving frequency of 4 to Ilz or higher.

By the way, it goes without saying that a print with a finer recording density is better as an image, but the higher the density, the more stable the droplet velocity is required, especially at 300 dpi or higher. 3K to record at 300dpi or higher
Drive must be performed at Hz or higher (to maintain the same printing speed).

However, due to problems in the production of head nozzles with conventional technology, foaming stability is poor in the high frequency range as long as commonly used recording liquids are used, and high-speed fluctuations of ejected droplets and non-ejection phenomena are often observed. Therefore, it was difficult to obtain high-quality images at high speed.

Therefore, an object of the present invention is to provide a liquid jet recording method that solves the various drawbacks and problems described above.

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

That is, the present invention has an orifice for discharging a liquid to form flying droplets, and a liquid flow path communicating with the orifice and having a heat acting part as a part of the structure, and wherein the heat acting part is a part of the structure. The nozzle density is 300 dpi (dot/1
In a liquid jet recording method using a liquid jet recording head having the following properties, 10% by weight of glycerin is added to the recording liquid.
Above, methanol 10% by weight or more, ethanol 5ffl
ffi% or more, isopropyl alcohol 3% by weight or more, and butanol 1% or more by weight.
This is a liquid jet recording method characterized by recording at 1z or higher.

(Function) According to the present invention, in a liquid jet recording head consisting of a thin film heating resistor and an inorganic protective layer, a foaming stable solvent such as glycerin, ethanol, butanol, etc. is contained in a predetermined ratio in an aqueous recording liquid. suppresses foaming fluctuations in the high frequency range, that is, suppresses droplet ejection speed fluctuations,
It is possible to improve the impact point density and the dot diameter variation.

This also eliminates printing defects due to non-ejection in the high frequency range.

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

The liquid jet recording head used in the present invention has the same configuration as that shown in FIG. 1, and a description of parts that overlap with the prior art will be omitted. However, the principle of generating the discharge pressure in the present invention is vaporization of the liquid and then foaming by energizing the heating resistor. The membrane structure is shown in FIG. This is 9 in Figure 1.
This is a cross-sectional view of the thermal resistor portion in the direction of the liquid flow path. In the figure, 1 is the Si substrate, 2a and 2b are the orifices, and the first
It corresponds to the figure. 3 is a heat generating resistive layer having a thickness of 123,500 mm in one embodiment of the present invention.

4 is patterned with individual or common ^l electrodes, and when energized, the shaded portion of the heating resistor 3 in the figure generates heat.

Further, as protective layers, 5in25 and Ta6 are laminated as shown in the figure.

Reference numeral 8 indicates a bubble formed when electricity is applied, and the pressure of the bubble causes the recording liquid to be ejected in the direction of → in the figure. In one embodiment of the present invention, a liquid jet recording head having the following configuration was used.

Recording density: 300 dpi (84.7 μm pitch) Number of liquid channels: 64 Channel width: 60 μm Channel height (h in the figure): 30 μm Heating resistor area: 30 x 150 μm By the way, in the above liquid jet recording head, the foaming state formed is Determine the discharge characteristics. FIGS. 3 and 4 show this relationship. Both the ejection speed and the ejection (droplet) volume are determined by the foaming length (strictly speaking, the foaming volume), and a proportional relationship holds. The problem here is the reproducibility of this foaming in the high frequency range. From FIG. 5 onwards, the frequency characteristics of the variation in foaming length due to each recording liquid composition are shown.

The recording liquid used in the above-mentioned recording apparatus is the same as the conventionally known aqueous recording liquid except for the specific organic solvent that is a feature of the present invention. The liquid medium is mainly composed of water, contains an appropriate amount of a water-soluble organic solvent for preventing drying, and may further contain various known additives.

In the following examples, only the composition of the liquid medium is shown.

Example 1 Recording liquid composition comparison ↓ Diethylene glycol 15% water by weight
85% by weight Example ↓ 2A Glycerin 15% by weight Water
85% by weight Glycerin, 30% by weight Water
70 weight! 11% In FIG. 5, σL/L on the vertical axis indicates the degree of variation, and the larger this value is, the more unstable it is. For example, when σL/L is 5%, that is, a width of ±11 μm for L = 220 μm appears as a width of ±0.5 m/S in discharge speed and ±69 fi in discharge volume, and the impact point error is ±5 μm. ±3μm as dot diameter
(1 to 2 mm from paper distance, carriage feed O,: 1 m/s). In the recording liquid in Comparative Example 1, especially in the high frequency region (loO11z~), σL/L
exceeds 5%, and therefore the impact point error and dot diameter variation are extremely large. On the other hand, in Example 1-a, it is stable at 4% or less even in the high frequency region. Further, increasing the glycerin ratio in the recording liquid increases stability (Example 1-b).

Example 2 Composition □ Diethylene glycol 45% water
55 weight hihatoshidiethylene glycol 45 f'l I1% butanol 5% water by weight
50, li amount% Also in this case, as in the first embodiment, a L/L in the high frequency region is small and stable at 5% or less (FIG. 6).

Example 3 Red side 1 Diethylene glycol 15% water by weight
85 weight Jj 1% Johachi Meishu Nidan diethylene glycol 15 weight h1% ethanol 20 weight % water
65 nails it% 5 points 1 21 diethylene glycol 15 heavy h1% ethanol 50ffl amount % water
65 weight h [% As shown in Fig. 7, a L/L is 5% in Example 3-a compared to the comparative example.
It is stable below. If the ethanol addition lit is further increased, it becomes about 2% and there is almost no variation.

Although not shown in this example, other additives (described below) also showed similar characteristics. Also, in this example, a large amount of added solvent is used, but in reality, it is sufficient that each solvent has at least the T content ratio shown below.
Further, addition of two or more types in combination also shows similar effects.

Glycerin 10% by weight or more Methanol 10% by weight or more Ethanol
Isopropyl alcohol at 5% by weight or more
3 weight 11% or more butanol 1 weight 1i
1% or more (Effect) As explained above, by adding a solvent that acts as a foaming stabilizer to the recording liquid, it increases the affinity with the inorganic protective layer of the heat generating resistor. It has the effect of increasing foaming stability in the high frequency range.

[Brief explanation of the drawing]

FIG. 1 is a perspective view I of a liquid jet recording head embodying the present invention.
A. Fig. 2 is a sectional view of the heating resistor portion, and Figs. 3 and 4 show the principle of the present invention. Figures 5 to 7 show the effects of embodiments of the present invention. Figure 1 1: Substrate 2a Niorifice 2b: Liquid flow path
30 Heating resistor 4: Common liquid chamber 5 2 Supply room Figure 2 1:, I! Plate 2a Niorifice 2b = Liquid flow path 30 Heating resistor 4: Electric rod
5. Protective layer 6: Protective layer 7: Top plate 8: Qi/1! ! (From) Patent Applicant Canon Co., Ltd. Agent Patent Attorney Yoshi 11 Katsuhiro Figure 1 Figure 2 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] It has an orifice for discharging a liquid to form flying droplets, and a liquid flow path communicating with the orifice and having a heat acting part as part of its structure, and the heat acting part is provided on a substrate. In a liquid jet recording method using a liquid jet recording head having a nozzle density of 300 dpi (dots/inch) or more consisting of a thin heat generating resistance layer and an inorganic protective layer, 10% by weight or more of glycerin and 10% by weight or more of methanol in the recording liquid. , a liquid jet recording method characterized by containing at least one solvent selected from the group consisting of 5% by weight or more of ethanol, 3% by weight or more of isopropyl alcohol, and 1% by weight or more of butanol, and recording at a driving frequency of 3KHz or more. .