JP2003127345A - Nozzle plate for ink jet head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a nozzle plate whose properties in rigidity, brittleness or the like is hardly lowered even if it is subjected to heating and melting treatment so that an ink repellency of an eutectoid plating layer of an Ni- fluorine compound is fully brought out, and which is also excellent in a discharge stability and mass-productivity. SOLUTION: An Ni-FEP eutectoid plating layer 108 is formed on an ink discharge surface side of the nozzle plate base 105 consisting of an Ni plated film, and an FEP pseudo surface layer is formed on its top surface by a heating treatment at 260 to 320 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head used in an inkjet recording apparatus, and more particularly to a nozzle plate of the inkjet head.

[0002]

2. Description of the Related Art In recent years, image forming apparatuses such as ink jet printers, copiers, and facsimiles have become very popular due to their advantages such as easy colorization and low noise. Among the inkjet methods, the so-called drop-on-demand type, which ejects ink droplets only when print recording is required, is the mainstream because it does not require the collection of ink droplets unnecessary for recording.

In general, an ink jet head used in a drop-on-demand type ink jet system is designed to press a nozzle plate having a plurality of nozzles, an ink liquid chamber communicating with each nozzle, and ink in each ink liquid chamber. Energy generating means (electromechanical conversion element such as piezoelectric element, electrothermal conversion element such as heater), and pressurizes the ink in the ink liquid chamber with the energy generated by the energy generating means to eject ink droplets from the nozzle. The type that makes it is the mainstream.

Recent ink jet recording apparatuses are required to have high quality printing, high speed printing, and power saving. Regarding the improvement of printing quality, the influence of the nozzle shape on the ejection performance is large, regardless of whether the inkjet head uses a piezoelectric element or an electric heat conversion element.
Further improvement is required. The influence of the shape inside the nozzle on the ejection affects the way the energy is propagated from the energy generating means to the ink and the process in which the ink forms droplets through the nozzle, and as a result, it has a great influence on the print quality. Therefore, in order to obtain a high quality image, it is necessary to eject the ink droplets only in one direction while controlling the shape of the flying ink droplets to be constant.

In order to eject ink droplets in only one direction while controlling the shape of the ink droplets, the shape of the ejected droplets when they are separated from the nozzle plate is important. In order to make the ink droplet shape uniform when the nozzle plate is detached, it is necessary to make the ink wettability around the nozzle uniform. That is, if the ink wettability around the nozzle plate is not uniform, the interfacial tension acting on the end portion of the ink droplet that separates from the nozzle plate becomes uneven in the circumferential direction of the nozzle, so that it is vertical and constant with respect to the nozzle plate. This is because the ink droplets will not be ejected in any direction.

On the other hand, if the wettability of the ink around the nozzles is increased uniformly in order to obtain ejection stability, in a multi-nozzle head in which a plurality of ejection holes are arranged at short intervals, mutual interference of meniscuses on the nozzle surface may occur. As a result, another problem arises in that stable ejection characteristics cannot be obtained and it is difficult to increase the density of the nozzle array.

Therefore, in order to improve the quality of printing, it is important to maintain uniform ink repellency around the nozzles. In order to improve the quality of printing, the composition of the ink, especially the type and amount of the surfactant has been studied. However, it has ink repellency with respect to the ink added with such various surfactants. It is important to form an ink layer around the nozzle.

As such an ink-repellent layer, a fluororesin-metal eutectoid plating layer is known (JP-A-7-13).
8763, JP-A-7-246707, JP-A-11-58746, JP-A-11-9109
0, etc. 2000-6422). In particular, an eutectoid plating layer of Ni and PTFE (polytetrafluoroethylene) is generally used. N
It is also known that heating the i-PTFE eutectoid plating layer improves and stabilizes the ink repellency. This is because a part of the PTFE particles on the surface of the eutectoid plated film is melted and melted to form a pseudo PTFE outermost surface layer although it is not dense. As a base for eutectoid plating, a polyimide resin having a surface layer made conductive or a metal such as Ni is adopted. In particular, Ni is often used because it is possible to perform precision processing relatively easily by combining a non-conductive pattern by photolithography and a Ni plating method.

[0009]

The nozzle plate for an ink jet head is required to have high rigidity in order to reduce the deformation due to the pressure when the ink in the liquid chamber is pressurized and to prevent mutual interference between nozzles due to vibration. But N
In a nozzle plate having an i-PTFE eutectoid plating layer as a surface layer, it is preferable for the physical properties of the base material that influences the rigidity of the nozzle plate to be subjected to a heat treatment to sufficiently melt and dissolve PTFE in the eutectoid plating layer. There was a problem that there was no impact. Specifically, in the case of a polyimide resin-based nozzle plate, the heating and melting of PTFE causes deterioration such as deformation of the polyimide resin itself. The Ni-plated film-based nozzle plate has a problem that rigidity is reduced and brittleness is increased.
There is also a problem that this reduces mass productivity.

By the way, in the case of Ni-PTFE eutectoid plating, since the melting point of PTFE is about 330 ° C., it takes about 350 ° C. to uniformly melt PTFE on the surface of eutectoid plating to form a pseudo surface layer of PTFE. The heat treatment for 30 minutes to 1 hour is required, and the change in physical properties of the base material due to heating is remarkable.

For example, when a polyamide-imide resin (PAI) or a polyimide resin (PI) is used as the base material of the nozzle plate, the change in the base material due to heating is investigated by DSC (differential scanning calorimetry). Shown in. PAI
In that case, since the oxidative deterioration starts at around 220 ° C. and the carbonization occurs after the PTFE heating and melting treatment, the nozzle plate cannot be manufactured. PI does not cause oxidative deterioration like PAI, but since the deformation of PTFE after heating and melting is large,
No nozzle plate that can withstand use is obtained.

In addition, when a Ni plating film processed with a plating solution containing an organic additive having a sulfur element in the molecule or an organic additive having a benzene ring skeleton is used as a base material, before heat-melting treatment of PTFE, Has an amorphous part in the base material, but after the treatment, the crystal grows and at the same time the amorphous property is impaired, resulting in a decrease in hardness and an increase in brittleness compared to before the heat-melting treatment. It becomes a tendency. FIG. 6 shows the change in hardness of the Ni plating film due to the heat treatment. Micro Vickers hardness was about 490Hv when not heated, but 350 ℃
After the heat treatment for 1 hour, the strength drops to about 235 Hv, and the strength required for the nozzle plate cannot be obtained. Further, the higher the heating temperature, the higher the brittleness of the substrate. 4mm diameter Ni
In the experiment using the rod, as shown in FIG. 7, fracture occurs after the heat treatment at 350 ° C. for 1 hour.

In view of the above problems, the present invention reduces the characteristics in terms of rigidity, brittleness, etc. even if a heating / melting treatment is carried out in order to sufficiently bring out the ink repellency of the eutectoid plating layer of Ni-fluorine compound. Therefore, it is an object of the present invention to provide a nozzle plate that is capable of stable ejection and has no deterioration in mass productivity, and a manufacturing method thereof.

[0014]

According to the present invention, as described in claim 1, as the surface layer of the nozzle plate, Ni is used.
An eutectoid plating layer of -FEP (tetrafluoroethylene hexafluoropropylene copolymer) is used. The base material for the surface layer includes a polyimide resin film (claim 2) whose surface has conductivity, a plate of a metal material such as Ni (claims 3 and 4), or an amorphous material. Ni
A plating film (claim 5) is used. Further, the nozzle plate of the present invention has a pseudo surface layer of FEP formed by heat treatment on the outermost surface of the Ni-FEP eutectoid plating layer, and the heat treatment for that is in the temperature range of 260 ° C or higher and 320 ° C or lower. (Claim 6).

FEP is weaker in strength such as tensile strength than PTFE, but has good ink repellency equivalent to that of PTFE. Further, since FEP has a melting point lower than that of PTFE by about 60 ° C., heat treatment for sufficiently bringing out the ink repellency of the eutectoid plating layer of a Ni-fluorine compound can be carried out at a low temperature, and thus sufficient ink repellency is obtained. It is possible to suppress the hardness decrease and deformation of the base material of the nozzle plate while ensuring the
It is possible to realize a nozzle plate with stable discharge performance and good handleability during assembly.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, some embodiments of the present invention will be described together with a manufacturing method thereof. In addition, some comparative examples will be described together to facilitate understanding of the present invention.

<< Embodiment 1 >> A nozzle plate according to this embodiment will be described with reference to FIGS.

First, a noise plate base having a round shape is prepared. As shown in FIG. 1A, the SU
A photoresist film 102 is formed on an S substrate 101 (at least the surface of which may be any substrate having conductivity), and the photoresist film 102 is subjected to steps of exposure, development, rinsing, and curing using a mask. A resist pattern 103 having a film thickness of 1.1 μm as shown in FIG. 1B is formed. Next, Ni plating is performed to form a Ni plating film 104 as shown in FIG. Then, Figure 1
As shown in (d), the SUS substrate 101 and the resist pattern 103 were peeled off to form a nozzle plate base 105 made of a Ni plating film 104. Ni plating film 1
The film thickness of 04 is about 30 μm so that the diameter of the nozzle 106 is about 30 μm.
It was adjusted to 30 μm. The nozzles 106 are arranged so as to have a resolution of 600 dpi.

In order to secure sufficient hardness and glossiness (leveled surface) of the Ni plating film, an organic additive having a sulfur element in the molecule or a benzene ring skeleton is used as a Ni plating solution used in the above Ni plating process. A plating solution containing an organic additive having is used. In this example, a plating solution containing an organic additive having a sulfur element in the molecule at a concentration of 3.0 g / l was used. The micro Vickers hardness of the obtained Ni plating film was 490 Hv. By ensuring the rigidity of the Ni-plated film in this way, defects due to handling in mass production of the nozzle plate / base are reduced, and the rigidity of the completed nozzle plate is increased to prevent mutual interference between nozzles in the plate. In addition, the leveling of the surface can prevent corrosion due to the ink.

As the organic additive having a sulfur element in the molecule or the organic additive having a benzene ring skeleton, sulfonic acid-based, sulfonamide-based, sulfonimide-based, coumarin and saccharin and their salts, etc. There is. Organic substances containing these sulfur elements in the molecule, or when organic additives having a benzene ring skeleton are added to the plating solution, they grow because the organic additives adsorb on the electrodeposition surface. Higher hardness can be obtained because the growing Ni hinders the crystal growth and, as a result, amorphousness is partially generated in the electrodeposited film.

Next, processing for imparting ink repellency is performed. As shown in FIG. 2A, a dry film resist is laminated on the round-shaped surface (the inner surface of the nozzle and the surface on the liquid chamber side) of the nozzle plate base 105 created by the above-mentioned procedure, By exposing the entire surface in that direction and developing it, the inner surface of the nozzle and the side surface of the liquid chamber of the nozzle plate base 105 are sealed and masked with a cured dry film resist 107. Then Ni
-FEP eutectoid plating was performed by an electrolytic method, and FIG.
As shown in FIG. 5, a Ni-FEP eutectoid plating layer 108 is formed on the discharge surface side of the nozzle plate base 105, for example, 2.0 μm.
It was formed to a film thickness of m. Then, as shown in FIG. 2C, the dry film resist 107 is removed by a dry film resist remover and an IPA rinse, and finally,
By carrying out the treatment of heating to 260 ° C, Ni-F
The FEP pseudo surface layer was formed on the outermost surface of the EP eutectoid plating layer 108 to complete the nozzle plate.

As described above, the above heat treatment deteriorates the amorphousness of the Ni plating film as the base material, lowers the hardness of the nozzle plate, and increases the brittleness. Since the heating temperature is low, the decrease in hardness and the increase in brittleness can be suppressed within the allowable range. According to the experiment, if the mask Rovicers hardness of the base material after the heat treatment is 270 Hv or more, a nozzle plate having stable ejection performance without causing deformation or damage that hinders handling is obtained. realizable.

Example 2 The nozzle plate of this example was prepared by the same procedure as the nozzle plate of Example 1, except that the heat treatment temperature of the Ni-FEP eutectoid plating layer was 29.
The temperature was 0 ° C.

Example 3 The nozzle plate of this example was prepared by the same procedure as the nozzle plate of Example 1, except that the heat treatment temperature of the Ni-FEP eutectoid plating layer was set to 32.
The temperature was 0 ° C.

<< Embodiment 4 >> In this embodiment, FIG.
As shown in (a), the nozzle 1 is formed by laser processing on a polyimide resin (PI) film 120 having a thickness of 200 μm.
21 is opened, and as shown in FIG. 3B, the Ni film 12 is formed as a conductive layer (excluding the nozzle portion) on the ejection surface side.
2 is formed by a sputtering method (conductivity treatment),
A nozzle plate base 123 was created. The configuration using such a PI film subjected to the electroconductivity treatment as a base has an advantage that the nozzle can be opened by laser processing or the like with a small number of steps.

Nozzle plate prepared in this way
Ni-F was formed on the ejection surface of the base by the same procedure as in Example 1.
An EP eutectoid plating layer was formed. However, the eutectoid plating was performed by an electroless method. Then, by heat treatment at 290 ° C, FE
A pseudo surface layer of P was formed to make a nozzle plate.

Comparative Example 1 A nozzle plate base was prepared using a polyamideimide resin (PAI) film having a thickness of 200 μm in the same procedure as in Example 4, and the surface on the discharge surface side was prepared as in Example 4 above. A Ni-PTFE eutectoid plated layer was formed by the same procedure, and heat treatment was further performed at 360 ° C.

Comparative Example 2 The same procedure as in Example 4 was repeated.
A nozzle plate base was prepared using a PI film having a thickness of 0 μm, and an eutectoid plating layer of Ni-PTFE was formed on the ejection surface side by the same procedure as in Example 4 above.
Heat treatment was performed at 0 ° C.

<< Comparative Example 3 >> The same procedure as in Example 1 was repeated.
A nozzle plate base made of an i-plated film was prepared, and the Ni-PT was formed on the ejection surface side by the same procedure as in Example 4.
A FE eutectoid plating layer was formed, and heat treatment was further performed at 360 ° C.

<< Comparative Example 4 >> By the same procedure as in Example 1,
Ni-on the nozzle plate base made of Ni plating film
A FEP eutectoid plating layer was formed and heat treated, and the temperature of the heat treatment was 240 ° C.

<< Evaluation Results >> A single evaluation of the nozzle plates of the above-mentioned Examples and Comparative Examples, and assembling of an inkjet head having a structure described later using these nozzle plates, and the ejection stability and handling at the time of assembly were judged as good or bad. The results of the evaluation are shown in FIG.

The nozzle plate of Example 1 has a micro-Vickers hardness of 360 Hv after the heat treatment and can suppress the decrease in hardness due to heating.
Since P was sufficiently melted, the ink repellency was also sufficient and the ejection stability was good. Deformation and brittleness did not hinder handling.

The nozzle plate of Example 2 also had good ink repellency because the FEP was sufficiently melted by heating. Also, the micro Vickers hardness is 32 by heating.
Although it decreased to 5 Hv, the ejection stability was good, and neither deformation nor brittleness caused any trouble in handling.

The nozzle plate of Example 3 had good ink repellency because the FEP was sufficiently melted by heating. Also, the micro Vickers hardness is 29 by heating.
Although it decreased to 0 Hv, the ejection stability was good, and neither deformation nor brittleness caused any trouble in handling.

The nozzle plate of Example 4 was free from deformation and damage, and had good ink repellency, ejection stability, and handling property.

The nozzle plates of Comparative Examples 1 and 2 were discolored and damaged by the heat treatment and could not be used as a nozzle plate.

In the nozzle plate of Comparative Example 3, the micro-Vickers hardness after heat treatment was reduced to 210 Hv, the mutual interference between the nozzles was caused as a result of the lowered rigidity, and the ejection stability was slightly unstable. . Further, the brittleness was large and the material was easily broken, so that the handling property was poor.

In the nozzle plate of Comparative Example 4, the micro Vickers hardness after heat treatment was 370 Hv, which was able to suppress the decrease due to heating, but the ink repellency was insufficient because FEP was not sufficiently melted. As a result, the ejection stability was not good.

In the present invention, FEP was used as the fluorine compound for eutectoid plating, but as a substitute candidate, another fluorine compound having a melting point lower than that of PTFE, such as PFA (tetrafluoroethylene perfluoroalkoxy). Ethylene copolymer resin), ETFE (tetrafluoroethylene
Examples thereof include ethylene copolymer resin) and ECTFE (ethylene-chlorotrifluoroethylene resin).

<< Inkjet Head >> An example of an inkjet head using the nozzle plate of the present invention described above will be described with reference to FIGS. 8 to 10. In the example shown here, the ink jet head is of a type in which a piezoelectric element deforms the pressurized liquid chamber (changing the volume) to eject ink droplets. The nozzle plate of the present invention can also be used for an inkjet head of a type that discharges by heating.

FIG. 8 is an exploded perspective view of the ink jet head, FIG. 9 is an enlarged sectional view of an essential part of the same head in a direction orthogonal to the channel direction (nozzle arrangement direction), and FIG. 10 is an enlarged sectional view of an essential part of the same head in the channel direction. It is a figure.

As shown in FIG. 8, this ink jet head comprises a drive unit 1, a liquid chamber unit 2, and a head cover 3. The drive unit 1 includes an insulating substrate 11 (for example, barium titanate,
Ceramic substrates such as alumina and forsterite)
A plurality of laminated piezoelectric elements 12 which are energy generating means are arranged in rows in two rows and bonded to each other, and a frame member 13 made of resin, ceramics or the like surrounding the piezoelectric elements 12 in the two rows is formed. It is a structure in which the adhesive 14 is used for joining. The plurality of piezoelectric elements 12 are composed of a piezoelectric element 17 to which a drive pulse is applied to make the ink droplets and to fly (this is referred to as a “drive piezoelectric element”) 17, and a liquid chamber unit 2 simply without a drive pulse. This is a configuration in which piezoelectric elements (which will be referred to as “non-driving piezoelectric elements”) 18 serving as liquid chamber column members that are fixed to the substrate 11 are alternately arranged. Usually, a method of dividing a long piezoelectric element material into individual piezoelectric elements 12 by groove processing is used.

As the piezoelectric element 12, a laminated piezoelectric element is used. For example, as shown in FIG. 9, this laminated piezoelectric element has a thickness of 10 to 50 μm / layer of lead zirconate titanate (PZT) 20 and a thickness of several μm / layer of silver / palladium (AgPd). However, the number of internal electrodes 21 is not limited to this. It is also possible to replace the piezoelectric element 12 with another electromechanical conversion element.

The inner electrodes 21 of the respective piezoelectric elements 12 are left and right end face electrodes 22 and 23 made of AgPd every other layer (the end faces of the two piezoelectric element rows facing each other are the end face electrodes 22 and the faces not facing each other are the end face electrodes 23). Connected. On the other hand, on the substrate 11, as shown in FIG. 8, Ni / Au vapor deposition, Au plating, AgP
Each pattern of the common electrode 24 and the individual electrode 25 is provided by t paste printing, AgPd paste printing, or the like. As shown in FIG. 9, the facing end electrodes 22 of the piezoelectric elements 12 in each row are connected to the common electrode 24 via the conductive adhesive 26, while the piezoelectric elements 12 in each row do not face each other. The end face electrodes 23 are similarly connected to the individual electrodes 25 via the conductive adhesive 26. By applying a driving voltage to the driving piezoelectric element 17 through such an electrical connection, an electric field in the stacking direction is generated in the driving piezoelectric element 17,
Displacement of elongation in the stacking direction occurs. The common electrode 24 is shown in FIG.
As also shown in FIG.
By filling the inside of a with the conductive adhesive 26, the conduction of the pattern connected to each piezoelectric element is achieved.

On the other hand, the liquid chamber unit 2 includes a vibrating plate member 31 made of a thin film of metal or resin and a liquid chamber member 32 made of resin or the like (in FIG. 8, only a part thereof is shown for convenience of drawing). And a nozzle plate 33 according to the present invention, and these members are sequentially laminated and joined by, for example, heat fusion. As shown in FIG. 9, the diaphragm member 31
Is a diaphragm portion 34 corresponding to the driving piezoelectric element 17.
And a beam 41 joined to the non-driving piezoelectric element 18 and a base 42 joined to the frame member 13. The vibrating plate member 31, the piezoelectric element 12, and the frame member 13 are joined by an adhesive 49. The diaphragm portion 34 is composed of an island-shaped convex portion 43 joined to the driving piezoelectric element 17, and a thin film portion (diaphragm region) 44 formed around the convex portion 43 and having a thickness of about 3 to 10 μm. Nozzles 38, which are fine ejection openings for ejecting ink droplets, are formed in two rows on the nozzle plate 33. By joining these three members, the pressurized liquid chamber 35 that is pressurized via each diaphragm portion 34 and the pressurized liquid chamber 35 located on both sides of this pressurized liquid chamber 35 are supplied to the pressurized liquid chamber 35. A common liquid chamber 36 that introduces ink, an ink supply path 37 that connects the pressurized liquid chamber 35 and the common liquid chamber 36, and a nozzle 3 that communicates with the pressurized liquid chamber 35.
And 8 form one channel. In this example, a plurality of channels are formed in two rows. As described above, the nozzle plate 33 according to the present invention suppresses warpage and embrittlement and has good handleability, so that it can be easily joined and assembled with other members.

The ink ejection surface (nozzle surface side) of the nozzle plate 33 is the ink repellent surface 47 having excellent ink repellency as described above, which stabilizes the ink drop shape and the flying characteristics, and provides high quality image quality. I am trying to get it. The peripheral edge of the nozzle plate 33 is a non-ink repellent surface 48 on which no ink repellent surface is formed.

After the drive unit 1 and the liquid chamber unit 2 are joined, the substrate 11 is supported and held on a spacer member (head holder) 50 which is a head supporting member, and the substrate 11 is disposed inside the spacer member 50. A PCB substrate having a head driving IC and the like and the electrodes 24 and 25 connected to the driving piezoelectric elements 17 of the driving unit 1 are connected via an FPC cable 51.

Further, the nozzle cover (head cover) 3
Is a box-like member for covering the peripheral portion of the nozzle plate 33 and the side surface of the head, and has an opening corresponding to the ink repellent surface 47 of the nozzle plate 33.
Is bonded to the non-ink-repellent treated surface 48 left on the peripheral edge portion of the. Further, in order to supply the ink from the ink cartridge (not shown) to the liquid chamber, the ink jet head is provided with ink supply holes 52, 5 in the spacer member 50, the substrate 11, the frame member 13 and the diaphragm 31, respectively.
3, 54, 55 are formed.

In the ink jet head having such a structure, the driving piezoelectric element 17 is displaced in the stacking direction by applying the driving voltage (pulse voltage of 10 to 50 V) to the driving piezoelectric element 17 according to the recording signal. Then, the pressurized liquid chamber 35 is inserted through the diaphragm portion 34 of the vibrating plate member 31.
Is pressurized to increase the pressure, and ink droplets are ejected from the nozzle 38. At this time, the pressurized liquid chamber 35 to the common liquid chamber 36
Although the ink flow also occurs in the direction of the ink supply path 37 leading to the ink, the ink supply path 37 having a narrow cross-sectional area acts as a fluid resistance portion to reduce the flow of the ink to the common liquid chamber 36 side, and the ink ejection efficiency is improved. Prevent the decline. Then, as the ink droplet ejection is completed, the ink pressure in the pressurized liquid chamber 35 is reduced, and a negative pressure is generated in the pressurized liquid chamber 34 due to the inertia of the ink flow and the discharge process of the driving pulse to fill the ink. Move to the process. At this time, the ink supplied from the ink tank flows into the common liquid chamber 36, and is filled in the pressurized liquid chamber 35 from the common liquid chamber 36 via the ink supply path 37. Then, the vibration of the ink meniscus surface near the outlet of the nozzle 38 is attenuated, and the surface tension causes the ink to be returned to the vicinity of the outlet of the nozzle 38 to reach a stable state, and the next ink droplet ejection operation is ready.

<< Inkjet Recording Device >> An example of an inkjet recording device using the above-described inkjet head will be described with reference to FIGS. 11 and 12. Figure 11
FIG. 12 is a schematic perspective view of an inkjet recording apparatus, and FIG. 12 is a schematic sectional view for explaining the internal structure of the apparatus.

This ink jet recording apparatus comprises a carriage movable in the main scanning direction inside the apparatus body 301, an ink jet head mounted on the carriage, a printing mechanism section 302 including an ink cartridge for supplying ink to the ink jet head, and the like. The device body 301
A paper feed cassette (or a paper feed tray) 304 capable of stacking a large number of papers 303 from the front side can be detachably attached to the lower part of the tray, and a manual feed tray for manually feeding the papers 303 can be attached. 305 can be opened and closed, the sheet 303 fed from the paper feed cassette 304 or the manual feed tray 305 is taken in, the desired image is recorded by the printing mechanism unit 302, and then the paper discharge tray 306 mounted on the rear surface side. Eject the paper.

The printing mechanism unit 302 slides the carriage 313 in the main scanning direction (the direction perpendicular to the paper surface in FIG. 12) by the main guide rod 311 and the sub guide rod 312 which are guide members which are horizontally mounted on the left and right side plates (not shown). The carriage 313 is freely held, and yellow (Y), cyan (C),
The inkjet head 31 having the above-described configuration for ejecting ink droplets of each color of magenta (M) and black (K)
4 is mounted with the ink droplet ejection direction facing downward.
The carriage 313 has an inkjet head 314.
Each ink cartridge 315 for supplying each color ink is replaceably attached.

The ink cartridge 315 has an atmosphere port communicating with the atmosphere in the upper part, and an ink jet head 314 in the lower part.
The ink is supplied to the inkjet head 314 with a slight negative pressure due to the capillary force of the porous body. There is.

Here, the carriage 313 is slidably fitted to the main guide rod 311 on the rear side (downstream side in the sheet conveying direction) and slidably mounted on the sub guide rod 312 on the front side (downstream side in the sheet conveying direction). It is placed in. Then, in order to move and scan the carriage 313 in the main scanning direction, a timing belt 320 is stretched between a drive pulley 318 and a driven pulley 319 which are rotationally driven by a main scanning motor 317, and the timing belt 320 is attached to the carriage 313. The carriage 313 is reciprocally driven by forward and reverse rotations of the main scanning motor 317.

On the other hand, in order to convey the paper 303 set in the paper feed cassette 304 to the lower side of the head 314, the paper feed roller 321 and the friction pad 322 for separating and feeding the paper 303 from the paper feed cassette 304, and the paper 30.
Guide member 323 for guiding the sheet 3 and the fed sheet 30
A conveyance roller 324 that reverses 3 and conveys the conveyance roller 324, a conveyance roller 325 that is pressed against the peripheral surface of the conveyance roller 324, and a leading end roller 326 that defines the feed angle of the sheet 303 from the conveyance roller 324 are provided. Conveyor roller 3
Reference numeral 24 is rotationally driven by a sub-scanning motor 327 via a gear train.

A print receiving member 329, which is a paper guide member for guiding the paper 303 sent out from the carrying roller 324 below the ink jet head 314 in correspondence with the range of movement of the carriage 313 in the main scanning direction, is provided. There is. A delivery roller 331 and a spur 332 that are driven to rotate in order to send out the sheet 303 in the sheet discharge direction are provided on the downstream side of the print receiving member 329 in the sheet transport direction. Roller 333
And a spur 334, and a guide member 33 that forms a paper discharge path.
5, 336 are provided.

At the time of recording, by driving the ink jet head 314 according to the image signal while moving the carriage 313, ink is ejected to the stopped sheet 303 to record one line, and the sheet 303 is moved by a predetermined amount. After transportation, the next line is recorded. Recording end signal or paper 303
By receiving the signal that the rear end of the recording area has reached,
The recording operation is terminated and the paper 303 is discharged.

Further, at a position outside the recording area on the right end side of the carriage 313 in the moving direction, the ink jet head 3
A recovery device 337 for recovering the ejection failure of No. 14 is arranged. The recovery device has a cap means, a suction means, and a cleaning means. The carriage 313 is moved to the recovery device 337 side during printing standby, the ink ejection port portion of the inkjet head 314 is capped by the capping means, and the ejection port portion is kept wet to prevent ejection failure due to ink drying. To do. Also,
By ejecting ink that is not related to recording during recording, the ink viscosity of all nozzles is made constant, and stable ejection performance is maintained.

When ejection failure occurs, the ejection port portion of the ink jet head 314 is sealed by the capping means, and the bubbles and the ink are sucked out from the nozzle by the suction means through the tube and the ink or dust attached to the ejection port portion is sucked. Etc. are removed by wiping with a member such as silicone rubber, and the defective ejection is recovered. Also, the sucked ink is stored in a waste ink reservoir (not shown) installed at the bottom of the main unit.
And is absorbed and held by the ink absorber inside the waste ink reservoir. As described above, since the nozzle plate of the present invention has excellent ink repellency and ejection stability, stable recording is possible for a long period of time.

[0060]

As described in detail above, according to the present invention, it is possible to realize a nozzle plate having good ink repellency and sufficient rigidity and exhibiting stable ejection performance.
Since the nozzle plate is less likely to be deformed or damaged, the handling property and the mass productivity can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view for explaining an example of a manufacturing process of a nozzle plate base.

FIG. 2 is a schematic cross-sectional view for explaining an example of an ink repellent treatment process for a nozzle plate.

FIG. 3 is a schematic cross-sectional view for explaining another example of the manufacturing process of the nozzle plate base.

FIG. 4 is a diagram showing evaluation results of examples and comparative examples.

FIG. 5 is a diagram showing changes in heating of PAI film and PI film.

FIG. 6 is a diagram showing changes in hardness of a Ni plating film due to heat treatment.

FIG. 7 is a diagram showing embrittlement of Ni by heating.

FIG. 8 is a divided perspective view showing an example of an inkjet head using the nozzle plate of the present invention.

FIG. 9 is a schematic partial cross-sectional view in the direction orthogonal to the channel direction of the inkjet head.

FIG. 10 is a schematic partial cross-sectional view of the inkjet head in the channel direction.

FIG. 11 is a schematic perspective view showing an example of an inkjet recording apparatus using an inkjet head incorporating the nozzle plate of the present invention.

FIG. 12 is a schematic cross-sectional view showing an internal configuration of the inkjet recording apparatus.

[Explanation of symbols]

101 SUS substrate 103 resist pattern 104 Ni plating layer 105 nozzle plate base 106 nozzles 107 Dry film resist 108 Ni-FEP eutectoid plating layer 120 PI film 121 nozzles 122 Ni plating film 123 nozzle plate base

Continued front page    F-term (reference) 2C056 EA21 HA24                 2C057 AF65 AF93 AG07 AG12 AP13                       AP55

Claims (6)

[Claims] 1. A FEP formed by a heat treatment on the outermost surface of a surface layer of a Ni-FEP (tetrafluoroethylene hexafluoropropylene copolymer) eutectoid plating layer on a substrate. Nozzle plate for inkjet head, characterized by having a pseudo surface layer of 2. The nozzle plate according to claim 1, wherein the base material is made of a polyimide resin subjected to a conductive treatment. 3. The nozzle plate according to claim 1, wherein the base material is made of a metal material. 4. The nozzle plate according to claim 3, wherein the metal material forming the base material is a metal material having a micro Vickers hardness of 270 Hv or more after the heat treatment for forming the pseudo surface layer. 5. The nozzle plate according to claim 1, wherein the base material is a Ni plating film containing an amorphous material. 6. A method for manufacturing a nozzle plate according to claim 1, wherein Ni-on the base material.
After forming the eutectoid plating layer of FEP, 260 ℃ or more, 320 ℃
A method of manufacturing a nozzle plate, comprising forming a FEP pseudo surface layer by heating in the following temperature range.