JP2998281B2 - Method of manufacturing ink jet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a recording head of an ink jet recording apparatus.

[0002]

2. Description of the Related Art An ink jet recording method is a non-impact recording method of low noise at the time of recording among various recording methods known at the present time. In addition, since an image is formed on a recording medium by flying ink droplets, high-speed recording is performed. It is recognized as an extremely useful recording method in that recording is possible and recording can be performed on plain paper without requiring special fixing processing.
In an ink jet recording head as shown in FIG.
The nozzle forming plate 3 is made of, for example, metal, ceramic,
It is made of silicon, glass, plastic or the like.
However, since the ink jet recording method forms an image on a recording medium by flying ink droplets, in the case of an ink jet recording head on the premise that the ink ejection surface is not wetted, the ink repellency of the surface having the nozzle (the ink Water-based inks are required to have water repellency, and oil-based inks are required to have oil repellency. If the ink repellency is insufficient, when the ink is ejected from the recording head, the ink adheres to the vicinity of the ejection port, causing non-uniform ink accumulation (wetting unevenness). In this case, as shown in FIG. 2, the flying direction is pulled toward the ink reservoir and deviates from the normal direction (flight bending). Further, because the unevenness of the wetting is unstable, the flight direction is disturbed each time the ink is ejected, and stable ink ejection cannot be performed, and good recording cannot be obtained.

[0003] In view of the above, various methods for improving the ink repellency by applying a surface treatment to part or all of a surface having a nozzle have been attempted.

For example, Japanese Patent Application Laid-Open No. 2-55140 discloses that an ink-repellent layer is formed by thermally vapor-depositing a fluorocarbon resin so as to surround a nozzle and depositing colloidal fluorocarbon during electroless nickel plating. A method of annealing to further increase the water repellency is disclosed.

[0005]

However, according to the method disclosed in the above publication, the ink repellent layer is formed at 200 ° C. → 400 ° C. → 400 ° C. → 400 ° C. → 2 in order to further enhance the ink repellency.
Annealing is performed by heating at a processing cycle of 00 ° C. for about 1.75 hours or heating at 300 ° C. for 1 hour, but in this case, the nozzle forming plate is not provided with the surface provided with the ink repellent layer. There is a problem that the plate is warped due to the difference in the coefficient of thermal expansion between the surface and the surface, and the ink flow path forming member and the nozzle forming plate cannot be adhered to each other during the assembling of the recording head.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has as its object that when ink is ejected from an ink jet recording head, the ink does not adhere to the vicinity of the ejection port, so that the ejection ink droplet does not bend and fly. An object of the present invention is to provide an ink jet recording head capable of performing high-quality recording for a long period of time.

Another object of the present invention is to provide a method capable of easily manufacturing the recording head with a high yield.

[0008]

According to a method of manufacturing an ink jet recording head of the present invention, a step of providing an ink-repellent layer by fluoropolymer eutectoid plating around a nozzle of a metal plate forming a nozzle; And a step of adhering the metal plate to the ink flow path forming member while applying heat to a temperature higher than the melting point of the fluoropolymer.

The metal plate forming the nozzle may be a single metal such as titanium, chromium, iron, cobalt, nickel, copper, zinc, tin or gold, or a nickel-phosphorus alloy or a tin-copper-phosphorus alloy (phosphor bronze). , Copper-zinc alloy (B
S) and alloys such as stainless steel (SUS) can be used.

In the step of providing an ink-repellent layer by fluoropolymer eutectoid plating around the nozzle, an appropriate metal such as nickel, copper, silver, zinc, or tin can be selected as a plating matrix. Is nickel (N
i) and nickel-cobalt alloy (Ni-Co), nickel-phosphorus alloy (Ni-P), nickel-boron alloy (N
Nickel alloys such as i-B) are selected because of their excellent surface hardness and wear resistance. Further, polytetrafluoroethylene (PTF
E), polyperfluoroalkoxybutadiene (PF
A), polyfluorovinylidene, polyfluorovinyl and the like can be used alone or as a mixture thereof. In addition, the heat treatment needs to be performed at least at a temperature equal to or higher than the lowest melting point of the eutectoid fluoropolymer. If the thickness of the ink-repellent layer is too thin, the ink repellency of the surface having the nozzle is insufficient if the eutectoid plating layer is too thin, and if the plating layer is too thick, the accuracy of the diameter of the nozzle is affected.
A range of 1 to 10 μm is appropriate. At this time, the eutectoid amount of the fluoropolymer in the plating layer was 5 to 60 vol.
%, Especially 10 to 50 vol%.

The pressure applied to the nozzle forming metal plate during the heating step is 100 gf / cm ² or more, preferably 5 gf / cm ² or more.
More than 00 gf / cm ² is appropriate. The pressure may be applied to only a required part of the metal plate or the entire metal plate.

Further, as materials for the ink flow path forming member, nickel, copper, zinc, tin, nickel-phosphorus alloy, tin-copper-phosphorus alloy (phosphor bronze), copper-zinc alloy (BS),
Metals such as stainless steel (SUS) and polycarbonate,
Plastics such as polysulfone, ABS resin (acrylonitrile / butadiene / styrene copolymer), polyethylene terephthalate, polyacetal, and amorphous polyolefin, as well as ceramics, silicon, and glass can be used.

Further, in the ink jet recording head as shown in FIG. 2, it is necessary that the ink flow path forming member is provided with an ink discharging element such as a piezoelectric element or a heating element.
This can be provided at any time before or after bonding the metal plate and the flow path forming member.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a sectional view of an ink jet recording head according to the present invention. Example 1 First, anodic electrolytic degreasing → water washing → acid immersion in hydrochloric acid → water washing →
Washing was performed in a process of strike plating with nickel chloride and washing with water. Subsequently, an unnecessary portion of the ink repellent layer, specifically, a portion to be bonded to the ink flow path forming substrate is protected with a polyester tape, and Ni / PT is treated with a plating solution having the following composition and conditions.
By performing FE eutectoid plating, the ink-repellent layer 9 was formed.

Plating solution composition Nickel sulfamate (Ni (NH ₂ SO ₃ ) ₂ ) 70 g / l H ₃ BO ₃ 30 g / l PTFE 55 g / l Conditions pH 4.0-4.5 Plating temperature 50 ° C. Cathode current Density 2 A / dm ² Stirring Slow mechanical stirring Next, after peeling off the polyester tape, a heat treatment was performed as shown in FIG. 3 using a stainless steel block 9 to obtain a nozzle forming metal plate 3. A pressure of 5 kgf / cm ² was applied to the entire metal plate, the heating temperature was 350 ° C. which was higher than the melting temperature of PTFE, and the treatment time was 2 hours.

Example 2 The pressure applied to the metal plate during the heat treatment step was 1 kgf /
A nozzle forming metal plate 3 was obtained in the same manner as in Example 1 except that the pressure was changed to cm ² .

Example 3 A stainless steel (SUS) plate in which a nozzle 4 was formed by punching with a press was used for cleaning in the same process as in Example 1. Then, unnecessary portions of the ink-repellent layer are protected with a photoresist, and Ni / Ni plating is performed with a plating solution having the following composition and conditions.
An ink repellent layer was formed by performing PFA eutectoid plating.

Plating solution composition Nickel sulfamate (Ni (NH ₂ SO ₃ ) ₂ ) 70 g / l H ₃ BO ₃ 30 g / l PFA 40 g / l Conditions pH 4.0-4.5 Plating temperature 50 ° C. Cathode current Density 2 A / dm ² Stirring Slow mechanical stirring Next, after removing the photoresist, a heat treatment was performed as shown in FIG. 4 using a stainless steel block 9 and a heat-resistant polyimide film 10 having a thickness of 100 μm to form a nozzle forming metal. Plate 3 was obtained. 500g for metal plate
A pressure of f / cm ² was applied, the heating temperature was 300 ° C. which was higher than the melting temperature of PFA, and the treatment time was 30 minutes.

Example 4 The pressure applied to the metal plate during the heat treatment step was 200 gf
A nozzle-forming metal plate 3 was obtained in the same manner as in Example 3 except that the pressure was changed to / cm ² .

Example 5 Using a nickel-phosphorus alloy (Ni-P) plate having a nozzle 4 formed by an electroless method, cleaning was performed in the same manner as in Example 1. Subsequently, unnecessary portions of the ink repellent layer are protected with a photoresist, and Ni plating is performed using a plating solution having the following composition and a condition.
/ PTFE eutectoid plating allows the ink repellent layer 5
Was formed.

・ Plating solution composition Nickel sulfate (NiSO ₄ .6H ₂ O) 240 g / l Nickel chloride (NiCl ₂ .6H ₂ O) 45 g / l Boric acid (H ₃ BO ₃ ) 35 g / l PTFE 50 g / l ・ Conditions pH 4.0-4.5 Plating temperature 60 ° C. Cathode current density 3 A / dm ² Stirring Slow mechanical stirring Next, after the photoresist is stripped off, heat treatment is performed using the iron block 11 as shown in FIG. A metal plate 3 was obtained. The pressure applied to the portion of the metal plate in contact with the block was 100 gf / cm ² , the heating temperature was 350 ° C., which was higher than the melting temperature of PTFE, and the treatment time was 3 hours.
0 minutes.

Comparative Example 1 A nozzle-forming metal plate 3 was obtained in the same manner as in Example 1 except that no pressure was applied to the metal plate during the heat treatment step.

Comparative Example 2 A nozzle-forming metal plate 3 was obtained in the same manner as in Example 3 except that no pressure was applied to the metal plate during the heat treatment step.

Comparative Example 3 The pressure applied to the metal plate during the heat treatment step was 10 gf /
A nozzle forming metal plate 3 was obtained in the same manner as in Example 5 except that the pressure was changed to cm ² .

The obtained metal plate 3 for forming a nozzle was bonded to the ink flow path forming member 1 made of polysulfone resin with an epoxy adhesive to manufacture an ink jet recording head.

Since the pressure of 100 gf / cm ₂ or more was applied to the plates of Examples 1 to 5 during the heat treatment process, there was no warpage, and the epoxy adhesive was applied to the ink flow path forming member 1 made of polysulfone resin. 1 was obtained, and the ink jet recording head as shown in FIG. 1 was obtained. On the other hand, the plates of Comparative Examples 1 to 3 were warped because they could not be accurately bonded to the ink flow path forming substrate. , An ink jet recording head could not be manufactured.

Further, the following ink repellency sustaining test was performed using the plates of Examples 1 to 5 and Comparative Examples 1 to 3.

Ink repellency sustaining test: After measuring the contact angle of each plate with ink A having the following composition, the plate was immersed in ink A and left in a constant temperature bath at 70 ° C. for 5 days. The state was visually checked, and the contact angle with the ink A was measured again. Table 1 shows the results.

The contact angle was measured by Kyowa Interface Chemical Co., Ltd. F
Using an ACE automatic contact angle meter PD-Z, it was measured at 25 ° C. after 60 seconds from the dropping of the ink.

Composition of Ink A I. Direct Black 154 1% Glycerin 3% Ethanol 5% Water 91%

[0032]

[Table 1]

As is clear from Table 1, the plate of Examples 1 to 5 in which only a pressure of less than 500 gf / cm ₂ was applied to the ink-repellent layer by the fluorinated polymer eutectoid plating during the heat treatment step. In Nos. 4 and 5, the ink repellency was initially high, but deteriorated by ink immersion. On the other hand, in Examples 1 to 3 in which a pressure of 500 gf / cm ₂ or more was applied, the ink repellency was not deteriorated by ink immersion, and the durability was high.

[0034]

As described above, according to the present invention, in the nozzle forming metal plate provided with the ink repellent layer, the warpage of the plate generated during the heat treatment step is suppressed, and the ink jet recording head can be easily manufactured with a high yield. Also,
The ink jet recording head of the present invention, when ejecting ink, does not stick to the vicinity of the ejection port, so that the flying of the ejected ink droplet does not bend and its effect is not deteriorated, so that high quality recording can be performed for a long time It was something.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an ink jet recording head of the present invention.

FIG. 2 is a diagram illustrating a conventional ink jet recording head.

FIG. 3 is a diagram showing a pressing method according to an embodiment of the present invention.

FIG. 4 is a diagram showing a pressing method according to an embodiment of the present invention.

FIG. 5 is a diagram showing a pressing method according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink flow path forming member 2 Ink flow path 3 Nozzle forming metal plate 4 Nozzle 5 Ink repellent layer 6 Ink ejection element 7 Drive line 8 Ink 9 Stainless steel block 10 Heat resistant polyimide film 11 Iron block

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Kobayashi 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation Inside (72) Inventor Masao Yamamori 3-35-5, Yamato, Suwa-shi, Nagano (56) References JP-A-60-183161 (JP, A) JP-A-57-72866 (JP, A) JP-A-1-280566 (JP, A) JP-A-2-70442 ( JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/135

Claims (2)

(57) [Claims] 1. A step of providing an ink-repellent layer by fluorine-based polymer eutectoid plating around a nozzle of a metal plate forming a nozzle, and heat-treating the metal plate to a melting point of the fluorine-based polymer or higher while applying a load. And a step of bonding the metal plate to an ink flow path forming member. 2. The method according to claim 1, wherein the pressure applied to the metal plate during the heating step is 10 gf / cm ² or more.