JPS62156971A - Forming of coated film - Google Patents

Abstract

PURPOSE:To provide a droplet jet recorder having a long useful life, by applying a raw material solution for forming a coated film of an inorganic material, and subjecting the applied solution to a baking treatment to provide the coated film of the inorganic material. CONSTITUTION:Corrosion of electrodes can be prevented from occurring by ensuring that adjacent ones of the electrodes are not in contact with a recording liquid. For example, in addition to a protective film which covers heat generating resistor patterns 23-1-23-5, a coated film for preventing the electrodes 21-1-21-5, 22-1-22-5 from making contact with a recording liquid is provided on the electrodes. It is preferable that the coated film is not provided on the resistor patterns, because if the protective film and the coated film are provided on the resistor patterns, the total thickness of the layers is large, leading to a poor heat transfer efficiency, which results in a lowering in the efficiency of ejecting droplets of the recording liquid. The material for forming the coated film may be, for example, a silicon rein, a fluoro resin or other similar resin, which is dried and hardened after being applied. It is also preferable to provide a film of a polyxylylene and a derivative thereof by vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a droplet jet recording apparatus which performs recording by ejecting a recording liquid, generally called ink, as small droplets from a fine orifice, and by simulating the adhesion of these droplets to a recording surface. The present invention relates to a droplet jet recording device with a new configuration that has improved durability in use. Among the various recording methods currently known, this is a non-impact recording method that generates almost no noise during recording, is capable of high-speed recording, and can record on plain paper without requiring any special fixing process. The so-called inkjet recording method (droplet jet recording method) is recognized as an extremely useful recording method. Various methods have been proposed for this inkjet recording method, some have been improved and commercialized, and others are still being worked on to put them into practical use. be.

The inkjet recording method uses various working principles to fly small droplets of recording liquid called ink.
Recording is performed by attaching it to a recording member such as paper. The present applicant has also already proposed a new system related to such an inkjet recording method.

This new system was proposed in Japanese Patent Application No. 118798/1982, and its basic principle is as outlined below.

In other words, this new inkjet recording method applies a thermal pulse as an information signal to the recording liquid introduced into a fine liquid chamber that can contain the recording liquid, and causes the recording liquid to change its state. In this method, the recording liquid is ejected and flown as small droplets from an orifice attached to the liquid chamber according to the acting force such as a generated pressure wave, and the recording liquid is attached to a member to be recorded to perform recording.

By the way, this new method has the great advantage that the configuration of the implementation device is simpler than the conventional one, and that the ejection orifice can be configured in a multi-array to easily adapt to high-speed recording, but on the other hand, the durability of the implementation device is It was recognized that he was at a disadvantage in that his sexual ability was not particularly high. That is, since this implementation device employs a heating resistor and its lead electrodes as a means for inputting thermal pulses to the recording liquid, these are repeatedly used in contact with the recording liquid. Over time, oxidation and corrosion often caused functional deterioration, and in some cases, the devices became inoperable. In addition, due to electrolysis of the recording liquid or corrosion of the leet electrode,
Inconveniences such as undissolved components mixed in the recording liquid and interfering with the intended ejection of droplets have also been observed.

Therefore, in the wood invention, the above patent application No. 52-118798
We propose a droplet jet recording device with a new configuration that completely eliminates the serious drawbacks seen in the ink jet recording method disclosed in the No. 1, and which is further improved.

That is, the main object of the present invention is to propose a droplet jet recording device that has a long service life.

Another object of the present invention is to provide a droplet jet recording device that is structurally simple and that ensures stable ejection of recording droplets over a long period of time due to thermal action. . In addition, another object of the invention is to provide a multi-array droplet jet recording device that guarantees excellent durability in use and high-speed recording.

The droplet jet recording device of the present invention that achieves these objects has a recording liquid movement path consisting of pores, and one end of this path is used as an ejection port, from which small droplets of the recording liquid are ejected. A device is provided that performs recording by ejecting and flying small droplets and making at least a portion of these droplets adhere to a recording surface, and in the movement path, a heat generating part is connected to this action to manually generate an electric signal. It is characterized by having a structure in which a lead electrode is provided therein, and a coating is formed on at least the lead electrode existing in the path to prevent the recording liquid from coming into contact with the lead electrode. be.

Hereinafter, the tree invention will be described in detail according to illustrated examples.

First, a specific example of a droplet jet recording apparatus according to the present invention and the principle of droplet jetting will be explained using FIGS. 1 and 2.

FIG. 1 shows an outline of the main parts of the droplet jet recording device.

That is, the heat generating part 2 is provided on the surface of the heat generating element installation board 1. Further, as the material for the substrate 3, glass, ceramic, heat-resistant plastic, or the like is used. A long groove 4 constituting a chamber 4' for accommodating ink before ejection and an ejection orifice 5 is formed in advance on the substrate 3.
After aligning the heat generating part 2 and the groove 4, the heat generating element installation board 1 and the heat generating element installation board 1 are joined and integrated with an adhesive. Next, the droplet jetting principle related to this illustrated device will be briefly described. FIG. 2 is a cross-sectional view of the groove 4 along the axis. The recording ink IK is supplied into the chamber 4' as indicated by the arrow in the figure.

Now, when an electric signal is applied from the outside to the heat generating part 2 attached to a part of the chamber 4', the heat generating part 2 generates heat and gives thermal energy to the ink IK in the vicinity thereof. The ink IK that has received thermal energy undergoes a state change such as volumetric expansion or the generation of bubbles, resulting in a pressure change, and this pressure change is transmitted in the direction of the ejection orifice 5, causing the ink IK to form small droplets 10.
It is discharged as follows. Recording is performed by attaching an arbitrary recording material such as paper (not shown) to this small print 10. FIG. 2 also shows the detailed structure of the heating element installation board 1, and the heating unit 2 includes a storage layer 7, a heating resistor 11, and an electrode 8 in this order on a substrate 6 made of alumina or the like.
After the heating resistor 11 and the electrode 8 are laminated using a thin film forming technique and patterned into a predetermined shape, a protective layer 9 made of a metal oxide is further laminated. This heat generating portion 2 is configured to be exposed inside the chamber 4'. In the heat generating section 2, the protective layer 9 is in direct contact with the ink IK.
However, this protective layer 9 prevents the heating resistor 11 from coming into direct contact with the ink TK and being oxidized, or conversely, preventing the ink IK from being electrolyzed. Specifically, this protective layer 9
The thickness of the ink layer determines the thermal response of ink droplet ejection or energy efficiency, so it is desirable that the ink layer be as thin as possible.

Next, what about the so-called single orifice type mentioned above? ′&
The following Figures 3(a) and 3(b) are schematic plan views of examples of the arrangement of the heat generating part and electrodes when the droplet jet recording device is changed to a multi-orifice type device. .

In FIG. 3(a), an electrode 21-1 made of aluminum or the like is shown. ..., 21-5 and 22-1.
..., 22-5. and heating resistor pattern 23-1.・
. . , 23-5 is shown, and this pattern will be abbreviated as U-shape in the following description.

Further, in FIG. 3(b), (lead) electrodes 24 and 25-1. ..., 25-5 and heating resistor pattern 26
-1. . . , 26-5 is illustrated.

In the following explanation, this pattern will be abbreviated as S type.

In each of the drawings, a flow path for ink, that is, a recording liquid, is provided in areas 27 and 28 surrounded by dotted lines.

When recording operations are continued using such a multi-orifice type droplet jet recording device equipped with a plurality of heating resistor patterns and their (leat) electrodes, the following phenomenon has conventionally been often observed. That is, (1) As the number and density of heating resistor patterns increases, electrode corrosion is more likely to occur in the recording liquid flow path;
As a result, the ejection condition of recording droplets becomes poor.

(2) Such electrode corrosion usually occurs as shown in Figure 3 (a).
In the illustrated example of FIG. 3(b), it was observed that this phenomenon occurred in the region indicated by the crossing line, that is, in the recording liquid relay chamber. It has also been found that the electrode corrosion progresses due to electrolysis occurring through the recording liquid based on the potential difference created between adjacent electrodes. Therefore, the inventor of the present invention realized that in order to prevent this electrode corrosion phenomenon, it is sufficient to maintain the adjacent electrodes in a non-contact state with the recording liquid, and came to propose the present invention. In other words, in addition to the protective film covering the heating resistor pattern, the specific measure of the present invention is to apply an organic or inorganic film on the (leat) electrode to prevent the recording liquid from contacting the electrode. The method is to provide a mixed coating.

Note that it is preferable that this film not be provided on the heating resistor pattern. This is because when a protective film and this coating are formed on the heating resistor pattern, the overall layer thickness increases.
This is because the heat transfer efficiency will be deteriorated, and the ejection efficiency of recording droplets will be reduced.

In the present invention, the material for forming the film on the (LEET) electrode must: 1) have good film-forming properties, 2) have a dense structure with few pinholes, and 2) be able to expand and dissolve in the ink used. It is desirable that the material has physical properties such as: - good adhesion with the lower layer such as the electrode layer, and - high heat resistance. , polybenzimidazole, metal chelate polymer, titanate ester, epoxy resin.

Phthalic acid resin, thermosetting phenolic resin, P-vinylphenol resin, Zyrotsuta resin, triazine resin, BT
Resin (triazine resin and bismaleimide addition polymer resin)
Resins such as are used.

To form a film of these resins, the resin is diluted with a solvent and then spin-coated onto the (lead) electrode (or protective film for the heating resistor in some cases).

After applying using methods such as spray coating and dip coating,
Just let it dry and harden.

In addition to this, it is also desirable to form a film using a polyxin rylene resin or a derivative thereof by vapor deposition.

Furthermore, various organic compound monomers such as thiourea,
Thioacetamide, vinyl furose, 1.3.
5-1-'J chlorobenzene, chlorobenzene, styrene, ferrocene, picoline, naphthalene, pentamethylbenzene, nitrotoluene, acrylonitrile, diphenylselenide, P-1-luidine, P-xylene, N
, N-dimedylene-P-1-luidine, toluene, aniline, diphenylmercury, hexamethylbenzene, malonitrile, tetracyanoethylene, thiophene, benzeneselenol, tetrafluoroethylene, ethylene, N-nitrosodiphenylamine, acetylene, 1
, 2, 4. -) Lichlorobenzene or propane may be formed into a film on the (lead) electrode by plasma polymerization.

Apart from these, an inorganic film can also be formed using a solution of butyl orthotitanate, ethyl silicate, or the like.

In the present invention, the thickness of the above-mentioned film is usually 0.01 μm to 10 μm, preferably 0.1 μm after drying.
~5 μm, optimally 0.1 μm to 3 μm.

In the present invention, there are two preferred methods of installing the coating as shown below. These are shown in schematic plan views in FIGS. 4 and 5.

That is, FIG. 4 schematically shows the recording head portion in which the aforementioned U-shaped pattern is formed, and in this case, the above-mentioned film is formed only in the area divided by the intersecting lines. In the recording liquid flow path outside this area, one (lead) electrode 11
-1. ....

21-5 does not come into contact with the recording liquid, the other electrode 22-1. ..., 22-5 will not be corroded even if it comes into contact with the recording liquid.

Next, FIG. 5 schematically shows the recording head portion on which the glue-type pattern described above is formed, and in this case, the electrodes 24, 25-1. ...,
25-5 is completely covered, the above-mentioned coating is formed over the entire area divided by the intersecting lines in the figure.

In addition, in FIG. 4 and FIG. 5, FIG. 3(a).

The same symbols as those in (b) are attached.

The respective explanations also adopt the explanations related to FIGS. 3(a) and 3(b).

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 11, Comparative Example First, a heating element installation board as shown in FIG. 4, which corresponds to the following Examples and Comparative Examples, was prepared in the following manner.

5i02 vaporized layer (thickness 5μm), Zr on alumina substrate
After sequentially forming the B2 heating resistor layer (800 layers thick) and the aluminum electrode layer (5000 layers thick), a heating resistor pattern 23-1 with a width of 40 μm and a length of 200 μm is formed by selective etching. ..., 23-5 was formed. Also, lead electrodes 21-1. of the same width are formed by etching. ....

21-5 and 22-1. ..., 22-5 was formed.

In addition to the above operations, heating resistor pattern 23-1.・・・
・A 5i02 protective film (thickness 1μ) is placed near 23-5.
was provided by sputtering.

In FIG. 4, the areas corresponding to the relay chambers for ink supply (indicated by crossed lines) are shown in Table-1 below and Table-1 below.
(Coatings) as described in No. 2 were laminated.

Separately, a glass plate (thickness: 1 mm) was provided with grooves 30 (width: 40 μm, depth: 40 μm) of the same number and pitch as the heating resistor pattern, as shown in FIG. 6, and an ink relay chamber. A grooved plate 32 was prepared by cutting grooves 31 using a micro cutter.

Each heating element installation board and grooved plate created in this way are bonded after aligning each heating resistor pattern with the groove, and further, an ink relay chamber from an ink supply section (not shown) is connected. Ink introduction pipe 3 for introducing ink into 31
3 is also connected to form the recording head block 3 as shown in FIG.
Completed 4 in one.

Furthermore, this block 34 includes the aforementioned electrodes, 21-1.・
..., 21-5 and 22-1. ....

A lead board having electrode leads connected to 22-5 was attached. Next, the discharge experimental conditions were as follows:
10 μS to the heating resistor pattern through the electrode lead.
4 with a pulse width of eC and a pulse input period of 200μsecC.
A rectangular voltage pulse of 0V was applied. Incidentally, the composition of the ink used was 70 parts of water, 29 parts of diethylene glycol, and 1 part of black dye.

When an ink ejection experiment was conducted using the above ejection test conditions and ink, as shown in Tables 1 and 2 below, the examples obtained superior results in the durability of the recording head compared to the comparative examples. Ta.

It was also excellent in recording performance.

The durability of these Examples and Comparative Examples was evaluated based on the number of times an electric pulse could be repeatedly applied to which the ink droplet ejection responded as follows.

A ------- 109 times or more Durability evaluation criteria B -------108 to 109 times C
------- It can also be seen from the examples of 105 times or less that the durability of the recording head is significantly improved by the presence of the coating on the electrodes.

Incidentally, as the heating element shown in the above explanation, one almost the same as a thermal print head (that is, a thermal head) conventionally widely used in the field of thermal recording can be applied. They are classified into thick film heads, thin film heads, and semiconductor heads depending on the manufacturing method, heating resistor, etc., but all of them can be used in the present invention. However, it is currently preferable to use a thin film head, especially when performing high-speed, high-resolution recording.

Furthermore, the recording ink used in the present invention comprises a main solvent such as water, alcohol such as ethanol, or toluene, and a wetting agent such as ethylene glycol, a surfactant, various dyes, etc. It is created by dissolving or dispersing it. Note that in order to prevent clogging of the ejection orifice, it is effective to filter the ink after it is produced or to provide a filter in the ink flow path, as in the case of existing inkjet recording methods.

As described in detail above, the present invention provides a recording head that can be applied to a high-performance droplet jet recording device that ejects ink stably over a long period of time and provides a high-quality recording surface at high speed. I can do it.

[Brief explanation of drawings]

1 and 2 are schematic diagrams for explaining a specific example of a droplet jet recording device according to the present invention and its droplet jetting principle, and FIGS. 3(a) and 3(b) are diagrams, respectively. FIGS. 4 and 5 are schematic plan views illustrating an example of the arrangement of the heat generating part and electrodes according to the invention, and FIGS. 6 and 7 are schematic plan views illustrating an embodiment of the present invention. 2A and 2B are schematic diagrams for explaining other embodiments of the present invention, respectively. In the figure, 2 is a heat generating part, 4' is a chamber, 5 is a discharge orifice, and 8.21-1. ..., 21-5°22-1. ...
, 22-5.24.25-1°..., 25-5 is an electrode, 9 is a protective layer, 11 is a heating resistor layer, 23-1...,
23-5.26-1°..., 26-5 is a heating resistor pattern, 27.28 is an ink flow path, 30.31 is a groove, I
K is ink.

Claims (1)

[Claims] (1) A method for forming a film, which includes a step of applying a raw material solution for forming an inorganic film, and a step of performing a baking treatment after the step to form an inorganic film.