JPH10138496A - Nozzle plate for ink jet head and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nozzle plate excellent in abrasion resistance, heat resistance, chemical resistance and thermal conductivity by carbonizing a nozzle plate, being employed in a head for jetting a droplet of ink liquid to a recording medium through an ink jet hole, in glassy state. SOLUTION: An ink jet head comprises a base plate 8, a cover plate 7 and a nozzle plate 2. The nozzle plate 2 is molded of a thermosetting resin molding material while taking account of dimensional shrinkage due to sintering. A molding thus obtained is precured, as required, and carbonized through sintering in vacuum or an inert atmosphere in glassy state. Subsequently, ink jet holes are made by means of excimer laser, lithography or electroforming. According to the method, features of glassy carbon, i.e., excellent abrasion resistance, heat resistance, chemical resistance and thermal conductivity, are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a nozzle plate for an ink jet head installed in an ink jet recording apparatus and a method of manufacturing the same.

[0002]

2. Description of the Related Art An ink jet type recording apparatus mainly prints desired characters and images on an opposing recording medium (recording paper) by ejecting ink droplets from fine nozzles having a diameter of several tens of μm. At present, as an ink jet head installed in this ink jet type recording apparatus, a drop-on-demand method in which ink droplets are ejected when necessary is mainly used. This type of inkjet head is
It is mainly composed of a nozzle plate having an ink ejection hole as shown in FIG. 1, an ink chamber for supplying ink to the nozzle plate, an ink groove, a pressure generating actuator provided in the ink chamber or the ink groove, and the like. By sending a printer control signal to the pressure generating actuator, pressure is applied to the ink, and ink droplets are ejected from the ink ejection holes toward a recording medium that is arranged opposite to the ink ejection holes. The pressure is generated by, for example, applying an electric signal to a laminated piezoelectric actuator to generate a pressure wave and ejecting ink droplets (for example, JP-B-53-12138, JP-A-63-247051). And a method in which ink is instantaneously vaporized and expanded by a heating resistor element to generate bubbles, and the ink droplets are ejected at the pressure (for example, Tominori Hara, Ichiro Endo, Journal of the Institute of Image Electronics Engineers, Vol. 11, No. 2, 1982) and the like.

[0003] As a method of manufacturing the nozzle plate of the ink jet head as described above, for example, polyimide,
A nozzle that forms a nozzle substrate by injection molding of a polymer material such as polysulfone, polyacetal, polyphenylsulfone, polyphthalamide, polyphenylene oxide, polycarbonate, polyetherimide, etc., and forms an ink ejection hole with a laser beam in the nozzle substrate A plate manufacturing method (for example, Japanese Patent Application Laid-Open No. 3-277554) is known.

[0004]

However, the above polyimide, polysulfone, polyphenylsulfone,
In a nozzle plate formed of a polymer material such as polycarbonate and formed with ink ejection holes, there has been a problem that the ink ejection holes are worn out due to long-term use of the recording apparatus. Also, due to the chemical reaction with the organic solvent component of the ink, a decrease in the mechanical strength of the nozzle plate occurs,
The shape of the nozzle hole changes, resulting in an adverse effect on the flight of the ink droplets, causing variations in the flight direction, and a problem of the chemical resistance of the resin used, that is, a reduction in print quality.

[0005] In order to solve the above problems, a hydrogenated amorphous carbon film is coated on the surface of an ink jet head part by a CVD method or the like to improve abrasion resistance and, if necessary, to reduce incompatibility with ink. In order to maintain for a long time, a method of performing a fluorination treatment on the surface of the hydrogenated amorphous carbon coating is disclosed in JP-A-4-229277, but in such a method, the nozzle surface has water repellency, It has excellent features such as prevention of nozzle hole blockage, good cutting of ink droplets, and prevention of diffusion and adhesion of ink droplets to adjacent nozzle holes.However, the adhesion between the resin used and the hydrogenated amorphous carbon coating is extremely high. Due to the low temperature, there has been a problem that mechanical peeling occurs with long-term use.

In the case of an ink jet head using a heating resistor element, the frequency of the element drive signal shifts to a higher frequency side due to a higher speed and a higher resolution of the apparatus based on recent technological advances. As the degree of integration has increased, there has been an increasing demand for heat resistance and thermal conductivity of the resin material forming the nozzle plate against heat generated by the elements. In addition, when forming a nozzle plate, ablation processing by excimer laser, lithography, and electroforming are mainly used because burr generation at the time of nozzle processing greatly affects ink flyability. Occurs, the resin plate has a large Young's modulus, so that it is difficult to remove the resin plate by secondary processing such as polishing.

Accordingly, the present invention has been made in view of the above-mentioned problems, and has abrasion resistance, heat resistance, chemical resistance,
It is an object of the present invention to provide a nozzle plate for an inkjet head having excellent thermal conductivity and a method for manufacturing the same.

[0008]

In order to achieve the above object, the present invention is characterized in that a nozzle plate used for an ink jet head for jetting ink droplets from an ink jet hole to a recording medium is made of glassy carbon. The size of the nozzle plate for the inkjet head and the substrate for the nozzle plate are expected to shrink in advance by baking using a thermosetting resin molding material containing a furan resin, a phenol resin, a polycarbodiimide resin or a mixture thereof as a main component. The method of manufacturing a nozzle plate for an ink jet head, comprising forming an ink ejection hole after firing the formed article in a vacuum or an inert atmosphere, Resin, phenolic resin, polycarbodiimide resin or a mixture thereof Using a thermosetting resin molding material in which the same type of cured resin fine powder is added to and mixed with the resin to be molded in a size that allows for dimensional shrinkage during firing in advance, and the obtained molded product is subjected to vacuum or an inert atmosphere. A method for manufacturing a nozzle plate for an inkjet head, comprising forming an ink ejection hole after baking.

[0009]

DETAILED DESCRIPTION OF THE INVENTION A nozzle plate for an ink jet head according to the present invention is instantaneously provided by an ink jet method in which an electric signal is applied to a laminated piezoelectric actuator to generate a pressure wave to eject ink droplets, or a heating resistor element. It is used for an ink jet head of an ink jet recording apparatus such as a bubble jet method in which bubbles are generated by vaporizing and expanding ink and ink droplets are jetted at the pressure.

As shown in FIG. 1, for example, the ink jet head is formed of three plates, a base plate (ceramic base plate) 8, a cover plate 7, and a nozzle plate 2. The base plate 8 includes an ink groove 3 serving as an ink flow path, a heating resistance element as an actuator 4 for generating pressure, an electrode for driving the element, and the like. The cover plate 7 includes an ink chamber 5 and an ink supply port 6. The base plate 8 and the cover plate 7 are positioned so that the corresponding ink grooves 3 are aligned with each other, and are used by being joined with an epoxy adhesive or the like. Things. Then, a joint end surface between the base plate 8 and the cover plate 7 (the front surface of the formed ink flow path).
The nozzle plate 2 is used after being joined.

The nozzle plate 2 is made of glassy carbon, has an ink ejection hole 1, and has a sectional shape as shown in FIG. 3, for example.

Hereinafter, a method for manufacturing the nozzle plate 2 will be described. First, a nozzle plate substrate is formed into a cross-sectional shape as shown in FIG. 2 using a thermosetting resin molding material in a size that allows for dimensional shrinkage during firing.

As the thermosetting resin molding material, a resin containing a furan resin, a phenol resin, a polycarbodiimide resin or a mixture thereof as a main component is used. Further, when a resin obtained by adding and mixing the same type of cured resin fine powder to the resin is used, better results can be obtained.

As the phenolic resin, the surface layer of a granular phenolic resin having a moisture content of 1% by weight or less, a particle diameter of 50 μm or less, and a heat fluidity of 60 to 160 mm as measured by a disc cure method has a melting point of 30%. It is desirable to perform injection molding using a granular phenol resin coated with a low surface tension substance at -160 ° C and a composition ratio of phenol resin to phenol resin of 0.2 to 5% by weight.

Further, the cured resin fine powder is preferably a granular phenol resin having a water content of 1% by weight or less, a particle size of 50 μm or less, and a heat fluidity of 0 to 10 mm as measured by a disc cure method.

The molding method of the thermosetting resin molding material includes:
Injection molding, press molding, cast molding and the like are mentioned, but in view of mass productivity, the injection molding method is preferable. When a thermosetting resin molding material containing a granular furan-based resin, phenol-based resin, polycarbodiimide-based resin or a mixture thereof as a main component is used, it is molded by an injection molding method or a press molding method. Similarly, in the case of using a thermosetting resin molding material in which the same type of cured resin fine powder is added to and mixed with a resin mainly composed of granular furan-based resin, phenol-based resin, polycarbodiimide-based resin or a mixture thereof. It is formed by an injection molding method or a press molding method.

Liquid furan resin, phenolic resin,
When a thermosetting resin molding material containing a polycarbodiimide-based resin or a mixture thereof as a main component is used, it is cast-cured and molded into a mold having a size that allows for dimensional shrinkage during firing. Similarly, liquid furan resin, phenolic resin,
Even when using a thermosetting resin molding material in which the same type of cured resin powder is added to and mixed with a polycarbodiimide-based resin or a resin containing a mixture of these as the main component, casting into a mold with dimensions that allow for dimensional shrinkage Curing molding.

The obtained molded product is precured if necessary, and then calcined and carbonized in a vacuum or an inert atmosphere to turn into a vitreous carbon. Next, the ink ejection holes are formed (ablated) by excimer laser, lithography, electroforming, or the like, so that the cross-sectional shape is as shown in FIG.

According to this manufacturing method, it is possible to provide a nozzle plate for an ink jet head having performances excellent in abrasion resistance, heat resistance, chemical resistance, and heat conductivity, which are characteristics of glassy carbon. Further, even when burrs are formed by processing using the above-described method other than the excimer laser, the glassy carbon can be removed by secondary processing by polishing such as lapping because the Young's modulus is small.

The present invention can be variously modified without departing from the gist thereof. For example, it can be used for a nozzle plate of an ink jet recording apparatus such as a piezoelectric actuator type. Further, the present invention can also be used for an ink groove serving as an ink flow path, a nozzle plate integrally formed with a shape for disposing a polarized piezoelectric actuator, and the like.

[0021]

The present invention will be described below in detail with reference to examples.

Example 1 As a resin for a nozzle plate material, a water content of 0.8% and a particle size were used.
Thermal fluidity measured by the disc cure method at 5-30 μm is 1
Using a granular phenolic resin of 59 mm in size, the orifice was molded by injection molding with a shape in which the ink jetting hole part was not a through-hole in anticipation of shrinkage during firing and carbonization. 16 under gas atmosphere
A carbon plate was fired at 00 ° C. to form a vitreous carbon, and a through-hole was formed at the orifice portion by an excimer laser to produce a vitreous carbon nozzle plate.

When a solvent resistance test was performed on the nozzle holes by ink jetting using a polyhydric alcohol such as diethylene glycol butyl ether or tripropylene glycol monomethyl ether as a solvent, the obtained glassy carbon nozzle plate showed excellent printing accuracy. Had been maintained.

Next, a high-frequency drive signal (1
To 2 kHz) for 30 minutes to increase the heat generation of the heating resistor element and observe the change in the temperature of the nozzle plate and the change in the shape of the nozzle hole. There was no change in the shape of the holes, there was no wetting between the nozzle holes that were locally close to each other, and good ink flying properties and ink water repellency were maintained.

The abrasion of the nozzle holes when the ink was continuously ejected for one month in a normal use environment was examined. In the nozzle plate of this embodiment, no abrasion of the nozzle holes was observed. No mutual wetting was observed, and no decrease in water repellency was observed.

Example 2 The same granular phenol resin as in Example 1 and a water content of 0.5%,
Using a resin mixed with a particulate phenolic resin fine powder having a particle diameter of 10 μm or less and a heat fluidity of 0 mm measured by a disc cure method, injection molding was performed, and a glassy carbon nozzle plate was formed in the same manner as in Example 1. Manufactured. When a solvent resistance test was performed in the same manner as in Example 1, the obtained glass-like carbon nozzle plate maintained excellent printing accuracy. Further, when the temperature change of the nozzle plate and the shape change of the nozzle hole were observed in the same manner as in Example 1,
The temperature rise was small, there was no change in the shape of the nozzle holes, there was no wetting between the nozzles, and good ink flying properties and ink water repellency were maintained. When the abrasion of the nozzle holes was examined in the same manner as in Example 1, no abrasion of the nozzle holes was observed, there was no wetting between the nozzle holes, and no decrease in the water repellency was observed.

Example 3 A nozzle plate made of glassy carbon was manufactured in the same manner as in Example 1 except that press molding was performed instead of injection molding. A solvent resistance test was performed in the same manner as in Example 1. As a result, excellent printing accuracy was maintained. Example 1
When the temperature change of the nozzle plate and the shape change of the nozzle hole were observed in the same manner as described above, the temperature rise was small, there was no change in the shape of the nozzle hole, there was no wetting between the nozzles, and good ink flying properties and ink repellency were observed. Water performance was maintained. When the abrasion of the nozzle holes was examined in the same manner as in Example 1, no abrasion of the nozzle holes was observed, there was no wetting between the nozzle holes, and no decrease in the water repellency was observed.

Example 4 A nozzle plate made of glassy carbon was manufactured in the same manner as in Example 2 except that press molding was performed instead of injection molding. A solvent resistance test was performed in the same manner as in Example 1. As a result, excellent printing accuracy was maintained. Example 1
When the temperature change of the nozzle plate and the shape change of the nozzle hole were observed in the same manner as described above, the temperature rise was small, there was no change in the shape of the nozzle hole, there was no wetting between the nozzles, and good ink flying properties and ink repellency were observed. Water performance was maintained. When the abrasion of the nozzle holes was examined in the same manner as in Example 1, no abrasion of the nozzle holes was observed, there was no wetting between the nozzle holes, and no decrease in the water repellency was observed.

Example 5 A nozzle plate made of glassy carbon was manufactured in the same manner as in Example except that granular furan resin was used instead of granular phenol resin. A solvent resistance test was performed in the same manner as in Example 1. As a result, excellent printing accuracy was maintained. When the temperature change of the nozzle plate and the shape change of the nozzle hole were observed in the same manner as in Example 1, the temperature rise was small, there was no change in the shape of the nozzle hole, there was no wetting between the nozzles, and a good ink was obtained. The flying property and the ink water repellency were maintained. When the abrasion of the nozzle holes was examined in the same manner as in Example 1, no abrasion of the nozzle holes was observed, there was no wetting between the nozzle holes, and no decrease in the water repellency was observed.

Comparative Example A polycarbonate, polyphenylsulfone, and polysulfone resins were injection-molded in a mold having the final dimensions, and through holes were formed with an excimer laser in the same manner as in Example 1.
A nozzle plate made of each resin was prepared. When a solvent resistance test was performed in the same manner as in Example 1, the printing accuracy was maintained in the obtained polyphenylsulfone nozzle plate. However, the nozzle peripheral portions in the polycarbonate and polysulfone nozzle plates were not changed. Eroded, it became difficult to maintain the nozzle shape, the ink flying direction varied, and the printing accuracy was greatly reduced.

When the temperature change of the nozzle plate and the change in the shape of the nozzle hole were observed in the same manner as in Example 1, since the polycarbonate and polysulfone nozzle plates had poor solvent resistance, the signal voltage was low. Immediately after the application of, the nozzle hole started to be deformed, so that the measurement could not be performed.
In the polyphenyl sulfone nozzle plate, although the nozzle hole shape was maintained, the plate temperature increased, the flying direction of each nozzle hole changed due to thermal expansion, and a phenomenon that the nozzle holes that were locally close to each other got wet occurred. Printing accuracy has decreased. Further, the abrasion of the nozzle hole was reduced in the same manner as in Example 1.
When only the nozzle plate made of polyphenylsulfone was examined for the above reason, the corner portion was worn at the orifice 9 shown in FIG. 3 and the diameter of the ink nozzle was increased by several μm. In addition, wetting occurred locally between the ink nozzles, and the printing accuracy was reduced.

[0032]

As described above, according to the present invention, there is provided a nozzle plate for an ink-jet head having excellent performances of abrasion resistance, heat resistance, chemical resistance and thermal conductivity which are the characteristics of glassy carbon. And the production method thereof can be provided.

[Brief description of the drawings]

FIG. 1 is a development view schematically showing an inkjet head.

FIG. 2 is a sectional view of a nozzle plate substrate according to one embodiment of the present invention.

FIG. 3 is a sectional view of a nozzle plate according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink ejection hole 2 Nozzle plate 3 Ink groove 4 Actuator for pressure generation 5 Ink chamber 6 Ink supply port 7 Cover plate 8 Base plate 9 Orifice

Claims (3)

[Claims] 1. A nozzle plate for an ink jet head, wherein a nozzle plate used for an ink jet head for jetting ink droplets from an ink jet hole to a recording medium is made of glassy carbon. 2. A nozzle plate substrate comprising a furan resin,
Using a thermosetting resin molding material containing a phenolic resin, polycarbodiimide resin or a mixture thereof as a main component, it is molded in a size that allows for dimensional shrinkage during firing in advance, and the resulting molded product is vacuum or inert. After firing in the atmosphere,
A method for manufacturing a nozzle plate for an inkjet head, comprising forming an ink ejection hole. 3. A nozzle plate substrate comprising a furan resin,
A phenolic resin, a polycarbodiimide resin or a resin mainly composed of a mixture of these resins is added with the same type of cured resin fine powder. A method for manufacturing a nozzle plate for an ink jet head, comprising: forming and firing an obtained molded product in a vacuum or an inert atmosphere, and then forming an ink ejection hole.