JP5651894B2 - Manufacturing method of jet plate - Google Patents

Description

The present invention relates to a manufacturing method of a spray plate used for a spray nozzle or the like for spraying a liquid or a granular material.

Spray technology is used not only in industry, but also in agricultural applications for agricultural chemicals. A spray plate made of metal such as stainless steel is frequently used for such spraying nozzles for spraying agricultural chemicals. In recent years, a spray plate excellent in durability capable of maintaining a constant spray amount and spray performance over a long period of time has been demanded due to the environmental impact of scattered agricultural chemicals and the problem of residual agricultural chemicals.
Therefore, ceramic jet plates with excellent wear resistance are commercially available (Patent Document 1). However, ceramic jet plates are more expensive to machine than metal press plates that can be press-molded, and the temperature is higher. There is also a problem of frost damage caused by moisture adhering to the blow plate in the winter season.
Further, as disclosed in Patent Document 2, it has already been proposed to coat diamond-like carbon (hereinafter abbreviated as DLC) as an improvement of a precision instrument jet plate such as an ink jet printer. However, when such a jet plate is used outdoors at a high water pressure, the surface coating easily peels off, and further requires corrosion resistance in addition to wear resistance. Therefore, it is difficult to put DLC coating to practical use as a spray plate for agricultural nozzles.
The DLC described here is a specific crystal structure in which sp ³ hybrid orbitals, which are three-dimensional bonds of carbon, and sp 2 hybrid orbitals, which are two-dimensional bonds, or bonds with hydrogen are irregularly mixed. This refers to a hard carbon-based film having an amorphous structure that does not have any. As a feature of this DLC film, it has high wear resistance, corrosion resistance, and the like.

On the other hand, regarding stainless steel, it has been pointed out that surface sensitization occurs depending on the surface temperature during coating, and the corrosion resistance deteriorates. According to Patent Document 3, sensitization can be avoided when DLC coating is performed at 450 ° C. or lower. However, as shown below, the surface temperature of the substrate (workpiece) to which DLC coating is applied should be accurately measured. Is difficult. For such temperature measurement, there are known a method in which a thermocouple is brought into contact with a substrate and a method in which measurement is performed in a non-contact manner using a radiation thermometer or the like. When measuring with the contact method, the plasma is applied to the thermocouple, and the measurement temperature may change or the thermocouple itself may be destroyed. The shape of the workpiece is limited, such as necessity. Further, when the entire substrate is coated, the temperature control of the entire substrate cannot be performed with this contact method. On the other hand, in the case of non-contact measurement, since a thick plasma cloud is gathered around the substrate, whether the temperature being measured is the temperature of the substrate itself or the temperature of the plasma itself clustered around it. I cannot make a distinction. Therefore, compared to cutting tools, etc. where DLC coating is often applied, many of the jet plate bases are small in size and rich in three-dimensional shapes, so the surface temperature of such jet plate bases can be accurately controlled. However, it is considered difficult to perform DLC coating.

JP 2008-80251 A (Ceramics nozzle) JP 2007-276344 A (Nozzle with DLC coating) JP 2008-163430 A (High corrosion resistance member and manufacturing method thereof) Patent No. 3555928 (surface modification method and surface modification apparatus)

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a method for manufacturing a jet plate excellent in corrosion resistance and wear resistance for continuously performing a certain amount of spraying. .

As described above, in order to continuously perform a certain amount of spraying, it is necessary to have excellent corrosion resistance and wear resistance. In order to achieve this object, the present inventors have studied various surface treatment methods. DLC coating is effective as a surface treatment with excellent wear resistance. Furthermore, by using the plasma ion implantation method, the indented inner surface of the spray plate substrate can be coated, and the surface temperature during the treatment is suppressed. Can do. As a result, it is possible to realize a spray plate having both wear resistance and corrosion resistance in stainless steel, which is supposed to cause sensitization at a surface temperature of 450 ° C. or higher. The inventor has obtained knowledge that it is possible to realize a synthetic resin jet plate having excellent wear properties, and has completed the present invention. That is, a method for manufacturing a jet plate according to the present invention is a method for manufacturing a jet plate in which a diamond-like carbon film is formed on the surface of a jet plate substrate having a spray port by a plasma ion implantation method. The step of forming an intermediate layer on the surface of the injection plate base by adding a silicon gas gasified by heating while applying a pulse bias voltage of minus 10 kV, and the step of forming the intermediate layer By applying a pulse bias voltage in the presence of hydrocarbon gas, which is a film forming raw material, to the jet plate substrate on which the intermediate layer is formed by the above , plasma is generated around the jet plate substrate, and ions in the plasma are injected into噴板substrate made and an ion implantation and deposition process to form a diamond-like carbon film on the surface of the噴板substrate, the ion implantation and Film process is characterized in that which is performed by applying, while varying with respect to the high frequency power supply a pulse bias voltage from the minus 15kV to minus 3 kV.

Further, in the above-described invention configuration, the spray plate substrate includes a peripheral plate portion and a conical recess portion formed by indenting upward from the bottom surface of the peripheral plate portion, and the spray port is formed at the top of the conical recess portion. It is formed so as to penetrate vertically.

Furthermore, in each of the above-described invention configurations, the diamond-like carbon film has a thickness of 0.5 μm or more and 5 μm or less.

In each of the above-described invention configurations, the injection plate base is made of stainless steel.

And in each above-mentioned each invention structure, a nozzle plate base | substrate is a product made from a synthetic resin.

Further, in each of the above-described invention configurations, the spray plate is used for an agricultural spray nozzle.

According to the jet plate according to the manufacturing method of the present invention, since the diamond-like carbon film is formed on the surface of the jet plate base having the spray port by the plasma ion implantation method, the DLC film is hardly peeled off. Thereby, the wear resistance of the injection plate can be improved and the life can be extended significantly. Incidentally, plating has been used as a surface modification of the injection plate substrate so far, but since it is difficult to distinguish between the base material and the plating in such a plating method, it is visually confirmed whether or not the plating has been peeled off. It was difficult to confirm. On the other hand, as a feature of the DLC coating of the present invention, the DLC film has a black glossy color and is greatly different from the color tone of the jet plate base. The adhesion of the drug can be confirmed immediately and easily.

Since the ion implantation and film forming steps of the plasma ion implantation method are performed by changing the pulse bias voltage from −15 kV to −3 kV to the high frequency power supply, there is no possibility of peeling of the DLC film due to stress in the film. In addition, a DLC film having a large adhesion force with the injection plate substrate and not being worn during the spraying operation can be obtained.

In addition, even when the spray plate base is a three-dimensional structure consisting of a peripheral plate portion and a conical recess, a DLC coating is applied not only to the spray port at the top of the conical recess, but also to the conical recess on the back of the spray plate. Can be done. Furthermore, since the DLC coating does not peel off over time at the boundary portion between the peripheral plate portion and the conical recess portion, the wear resistance can be improved and the life of the jet plate can be extended significantly.

Further, when the thickness of the diamond-like carbon film is 0.5 μm or more and 5 μm or less, sufficient durability of the injection plate is obtained, and the DLC film is not worn by the spray pressure. Further, there is an advantage that the DLC film is not peeled off due to internal stress, and the film forming cost can be reduced instead of the obtained durability.

Further, it is possible to use an inexpensive and easily available stainless steel or synthetic resin as the base plate, and to provide an inexpensive base plate despite its high corrosion resistance and wear resistance. it can.

It is a perspective view of the injection plate concerning one embodiment of the present invention. (A) is a longitudinal cross-sectional view of the said injection plate, (b) is a longitudinal cross-sectional view of the spray nozzle equipped with the said injection plate. It is a schematic block diagram which shows an example of the plasma ion implantation apparatus used when forming a DLC film in the nozzle plate base | substrate of the said nozzle plate. It is a perspective view of the jet plate which concerns on another embodiment of this invention. It is a longitudinal cross-sectional view of the spray nozzle equipped with the another jet plate. It is a schematic block diagram of the spray test apparatus using the spray nozzle provided with the said jet plate. It is a figure showing the relationship between the elapsed time and the spray rate increase rate in the spray test of the spray plate which performed the DLC coating process, and the spray plate which has not performed the DLC coating process. (A) is the figure of the electron micrograph before and behind the spray test of the spray plate end surface which performed DLC coating processing, (b) is the figure of the electron micrograph before and after the spray test of the spray plate end surface which has not performed DLC coating processing. . (A) is a photograph of a photograph taken from the bottom of a jet plate subjected to DLC coating by applying a minus 3 kV pulse bias voltage in Example 6 and subjected to the spray test of Example 5, and (b) is an implementation. A photograph of a photograph taken from the bottom of the spray plate subjected to the DLC coating applied with a pulse bias voltage of minus 15 kV in Example 6 and subjected to the spray test of Example 5, and (c) is a DLC coating in Example 2 FIG. 7 is a photograph of a photograph taken from the bottom of a spray plate subjected to a 200-hour spray test according to Example 5;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the scope of the invention. 1 is a perspective view of an ejection plate according to an embodiment of the present invention, FIG. 2 (a) is a longitudinal sectional view of the ejection plate, and FIG. 2 (b) is a longitudinal sectional view of a spray nozzle equipped with the ejection plate. is there.
1 and 2, a jet plate 1 according to the present embodiment has a jet-like substrate 2 coated with diamond-like carbon (DLC), and a DLC film 6 is formed on the entire surface of the jet plate base 2. . The jet plate base 2 is formed so as to penetrate up and down at the top of the conical portion 4 and the conical portion 4 that protrudes upwardly connected to the inner edge of the peripheral plate portion 3 formed in a circular ring shape in plan view. And a spray port 5. The bottom surface (back surface) of the conical portion 4 is a conical concavity portion 4A formed by indenting upward from the bottom surface 3A of the peripheral plate portion 3. Such a jet plate 1 is used as a main part of a spray nozzle used for, for example, spraying agricultural chemicals. As shown in FIG. 2, the spray nozzle 10 includes a nozzle main body 11 having a liquid flow path therein, a swivel core 14 that is disposed in the liquid flow path of the nozzle main body 11 to give a swirl flow to the fluid, A nozzle plate 1 installed at the upper end opening of the core 14, a pressing member 15 which is installed on the peripheral plate portion 3 of the nozzle plate 1 and depresses the nozzle plate 1, the turning core 14 and the O-ring 13, and a nozzle body 11 and a cap 12 that is screwed to 11 to fix the pressing member 15.

Various methods are known as the DLC film formation technique described above, but it is a three-dimensional structure having a conical recess as in the injection plate substrate of the present invention, and a coating process is also applied to the deep part of the concavity. For an object to be deposited, plasma ion implantation is preferred because of its good film formability and adhesion. This “plasma ion implantation method” is a method in which a high voltage pulse is applied to a spray plate substrate immersed in plasma, and carbon or the like is accelerated by a sheath electric field formed on the surface of the spray plate substrate to perform coating or ion implantation. Since an ion sheath can be formed along the surface of the jet plate substrate, ions can be implanted into the three-dimensional surface, and ions can be directly extracted from the plasma around the jet plate substrate, so that the ion current can be increased. is there. Therefore, the film formation time can be shortened, and the temperature rise of the injection plate substrate can be suppressed.

The DLC in the present invention is preferably formed on the surface of the injection plate substrate by a plasma ion implantation method to which a pulse bias voltage of minus 15 kV to minus 3 kV is applied. The reason is that when the pulse bias is less than minus 15 kV, there is a problem that the DLC film peels off due to stress in the film. On the other hand, when the pulse bias voltage exceeds −3 kV, the adhesion between the injection plate substrate and the DLC film becomes small, and thus there is a problem that the DLC film is scraped during the spraying operation.

The material of the injection plate base used in the present invention is not particularly limited as long as it has a certain level of hardness and strength, but for example, metals, synthetic resins, ceramics and the like can be used. Among them, examples of the metal include steel materials that can be press-molded, such as stainless steel, titanium alloy, and aluminum alloy. As the synthetic resin, polyethylene, polyvinyl chloride, or the like that can be molded by an injection molding method or a compression molding method can be used.

When the DLC film is formed on the above-described nozzle plate base, a plasma ion implantation apparatus as shown in FIG. 3 is used. The plasma ion implantation apparatus 20 includes, for example, a vacuum chamber 21, a metal conductor electrode 23 provided through the vacuum chamber 21 through an insulating portion 22, a high-frequency power source 24 connected to the conductor electrode 23, and a direct current. A pulse bias power source 25, a vacuum exhaust device 26 connected to the vacuum chamber 21, and a gas supply device 27 connected to the empty chamber 21 are configured. As such a plasma ion implantation apparatus 20, for example, a commercially available apparatus manufactured by Kurita Manufacturing Co., Ltd. can be used. A spray plate substrate 2 as a sample is attached to the tip of the conductor electrode 23.

In this plasma ion implantation apparatus 20, first, a vacuum chamber 21 in which the nozzle plate base 2 is disposed in the chamber is vacuum-evacuated by a vacuum exhaust device 26, and then the low-pressure hydrocarbon gas ( Plasma forming gas) is introduced. Then, a matching circuit (not shown in the drawing), for example, an AC high frequency pulse voltage of 13.56 MHz and a DC negative high voltage pulse voltage output from the plasma generating high frequency power source 24 and the ion implantation pulse bias power source 25 is used. ) To overlap (bond to each other while preventing mutual inductive failure). Then, the superimposed electric power is applied to the injection plate base 2 via the conductor electrode 23. As a result, a hydrocarbon gas plasma is generated around the jet plate substrate 2 and ions in the plasma are attracted and injected into the jet plate substrate 2 by a negative high voltage pulse bias voltage. In addition, a DLC film is formed on the surface of the spray plate substrate 2 while the ion radicals are bombarded and bombarded with ions.

The DLC film formed by this plasma ion implantation method has the thickness, hardness, etc., by the following three steps of “ion implantation to the substrate surface”, “formation of intermediate layer”, and “film formation”. Can be adjusted. That is, in step "ions Note entry into surface" increases the surface hardness by using a silicon-based gas such as hydrocarbon gas or hexamethyldisiloxane and tetramethylsilane, such as methane and acetylene. Similarly, in the “intermediate layer formation” step , adhesion is improved by a hydrocarbon gas or a silicon-based gas. In the final “film formation” step, the thickness of the DLC film is adjusted. In each stage described above, the thickness, hardness, etc. of the DLC film to be formed are adjusted by appropriately setting the type of the introduced gas, the introduced gas flow rate, the degree of vacuum, the high frequency power, the high voltage pulse interval, etc. Can do.

By adjusting as described above, the DLC film formed on the injection plate base of the present invention is preferably coated in a range of about 0.5 to 5 μm. This is because if the thickness of the DLC film is too thin than the above range or the film hardness is too low, sufficient durability as a spray plate cannot be obtained, and the DLC film is worn out by the spray pressure of the spraying operation. To do. Conversely, if the DLC film is too thick or too hard, the DLC film is easily peeled off due to internal stress, and durability is only slightly improved for the film formation cost.

As described above, the method of forming the DLC film by the plasma ion implantation method is extremely suitable for the “three-dimensional” jet plate base which is difficult to form a DLC film having high film strength and high durability. . That is, it is also suitable for the three-dimensional injection plate base 2 in which the angle θ (see FIG. 2) formed by the bottom surface 3A of the peripheral plate portion 3 and the inner peripheral surface of the conical recess portion 4A is 40 degrees or more and 80 degrees or less. It can be used. On the other hand, in the spraying operation, it is assumed that wear at the boundary position indicated by 6A in FIG. 2A is likely to occur, but the occurrence of wear at the boundary position 6A is prevented by coating the DLC film 6. Can do.

In the above embodiment, the jet plate 1 made from the three-dimensional jet plate base 2 having the conical indented portion 4A formed by indenting upward from the bottom surface 3A of the peripheral plate portion 3 is exemplified. The jet plate of the present invention is not limited to the one using the jet plate base having such a three-dimensional shape. As shown in FIG. 4, for example, a jet plate 1a using a jet plate base 2a formed by press molding or the like from a plate material such as a stainless steel plate is also included in the present invention. In this jet plate 1a, a DLC film 6 is formed on the entire surface of a flat plate-like jet plate base 2a having a spray port 5 in the center.

The nozzle plate 1a is used in a spray nozzle 10 as shown in FIG. The spray nozzle 10 a is screwed to, for example, a nozzle body 11 a having a liquid channel inside, a spray plate 1 a installed at the upper end opening of the liquid channel of the nozzle body 11 a, and an upper edge of the nozzle body 11. The cap 12 which fixes the jet plate 1a and the seal ring 13a, and the turning core 14a which is arrange | positioned in the liquid flow path of the nozzle main body 11a and gives a swirl flow to the fluid are provided. Such a flat plate 1a has a simpler structure and can be provided at a lower cost than the previously described plate 1. And although it is cheap, it has both corrosion resistance and wear resistance.

Subsequently, the present invention will be described in more detail by way of examples.
First, Example 1 will be described.
“DLC coating with a thickness of 0.5 μm on stainless steel spray plate”:
Plasma ion implanter (manufactured by Kurita Manufacturing Co., Ltd.) for a spray plate substrate made of stainless steel (SUS 304) having a diameter of 15 mm and a thickness of 0.5 mm and having a conical portion having a diameter of 10 mm and a height of 5 mm with a spray port at the tip. : See Fig. 3). As a pretreatment at that time, hexamethyldisiloxane gasified by heating (being an intermediate layer) was added while applying a minus 10 kV pulse bias voltage. Thereafter, acetylene was used as a film forming raw material, and a DLC coating was applied at a high frequency power output of 50 W while changing a pulse bias voltage of −15 kV to −3 kV, thereby forming a DLC film over the entire surface of the injection plate substrate. . At this time, the silicon substrate partially masked together with the nozzle plate substrate was also put in the same vacuum chamber and DLC coating was performed. After coating, the step between the silicon substrate and the DLC film was measured with a surface roughness meter. It was 5 μm. From this, it was estimated that the thickness of the DLC film on the surface of the injection plate substrate was 0.5 μm.

“DLC coating with a thickness of 3 μm on stainless steel spray plate”:
Plasma ion implanter (manufactured by Kurita Manufacturing Co., Ltd.) for a spray plate substrate made of stainless steel (SUS 304) having a diameter of 15 mm and a thickness of 0.5 mm and having a conical portion having a diameter of 10 mm and a height of 5 mm with a spray port at the tip. DLC coating was applied using As a pretreatment at that time, hexamethyldisiloxane gasified by heating was added as an intermediate layer while applying a pulse bias voltage of minus 8 kV at a pressure of 0.4 Pa. Thereafter, acetylene was used as a film forming material, and DLC coating was performed with a high frequency power output of 50 W while gradually changing the pulse bias voltage of minus 10 kV to minus 3 kV at a pressure of 1.2 Pa. And when the thickness of the DLC film on the surface of the injection plate substrate was estimated by the same method as in Example 1, it was 3 μm.

“DLC coating with a thickness of 5 μm on stainless steel spray plate”:
Plasma ion implanter (manufactured by Kurita Manufacturing Co., Ltd.) for a spray plate substrate made of stainless steel (SUS 304) having a diameter of 15 mm and a thickness of 0.5 mm and having a conical portion having a diameter of 10 mm and a height of 5 mm with a spray port at the tip. DLC coating was applied using As a pretreatment at that time, hexamethyldisiloxane gasified by heating was added as an intermediate layer while applying a pulse bias voltage of minus 8 kV at a pressure of 0.4 Pa. Thereafter, DLC coating was performed with a high frequency output of 50 W using acetylene as a raw material while gradually changing the pulse bias voltage of minus 10 kV to minus 3 kV at a pressure of 1.2 Pa. And when the thickness of the DLC film was estimated by the method similar to Example 1, it was 5 micrometers.

“DLC coating with a film thickness of 3 μm on a synthetic resin spray plate”:
Plasma ion implantation device (manufactured by Kurita Manufacturing Co., Ltd.) for a spray plate base made of synthetic resin (polyethylene) having a diameter of 15 mm and a thickness of 0.5 mm and having a conical portion having a diameter of 10 mm and a height of 5 mm with a spray port at the tip DLC coating was applied using In the vacuum chamber, a synthetic resin jet plate base was placed in such an arrangement that the incoming ions hit the metallic negative electrode, and DLC coating was performed. As a pretreatment at that time, hexamethyldisiloxane gasified by heating was added as an intermediate layer by applying a minus 10 kV pulse bias voltage. Thereafter, a DLC film having a thickness of 3 μm was coated on the substrate surface while changing the pulse bias voltage of −15 kV to −3 kV using acetylene as a film forming material. The product ejection plate that was taken out was confirmed, but no deterioration due to temperature rise due to plasma was observed.

“Spray test on stainless steel spray plate”:
A spray test was performed on the DLC-coated spray plate produced in Example 1 and Example 3 using a circulation type spray test apparatus 30 as shown in FIG. The spray test apparatus 30 includes a liquid storage tank 31 that stores a calcium carbonate aqueous solution C obtained by diluting calcium carbonate with 80 times water, a stirrer 32 that is provided in the liquid storage tank 31 and stirs the calcium carbonate aqueous solution C, A circulation path 34 having one end disposed in the liquid storage tank 31 and the other end disposed in an upper space in the liquid storage tank 31; a spray nozzle 10 with the injection plate 1 connected to the other end of the circulation path 34; A power sprayer 33 that pumps the liquid in the liquid storage tank 31 in the circulation path 34 and a pressure gauge 35 for detecting the liquid flow rate in the circulation path 34 are provided. Since the power sprayer 33 is a general-purpose machine, the illustration of the structure is omitted. However, for example, a cylinder having a water inlet to which a circulation path 34 is connected, a piston with a valve that reciprocates in the cylinder, and a piston are driven. A drive mechanism, a discharge valve at the tip of the cylinder connected to the spray nozzle 10, an air chamber for accumulating fluid pressure on the discharge side, and a pressure regulating valve for setting the discharge pressure are provided.

In the spray test apparatus 30, the power sprayer 33 pumps the calcium carbonate aqueous solution C into the circulation path 34 at a discharge pressure (set pressure) of 2.0 MPa, and the spray nozzle 10 supplies the spray plate 1 to the liquid storage tank 31. To spray. At this time, from the pressure difference between the pressure measured by the pressure gauge 35 and the constant discharge pressure set by the power sprayer 33, the flow rate, that is, the spray amount in the circulation path 34 is estimated. Then, the change in the spray amount after a certain time was calculated, and the result obtained by dividing the change by the spray amount at the initial stage of the test was derived as a percentage by increasing the spray amount. In addition, the test was performed simultaneously with the injection plate of each Example, as well as the reference surface untreated stainless steel (SUS 304) injection plate substrate (Comparative Examples 1 to 3 (both of the same production lot products)). .

First, the spray plate of Example 1 having a DLC film thickness of 0.5 μm and the spray plate (base) of Comparative Example 1 were subjected to the spray test apparatus 30 and subjected to a spray test for 10 hours. The results are shown in Table 1 below.

According to Table 1, while the spray plate of Example 1 subjected to DLC coating (film thickness 0.5 μm) had a spray rate increase rate of 2.2%, the spray plate (substrate) of Comparative Example 1 At 4.7%, the increase rate is twice or more, and it can be seen that the spray plate (substrate) has a large wear on the spray nozzle. After the test, when the surface of the ejection plate of Example 1 was observed with the naked eye, partial peeling of the DLC film was confirmed.

Next, the spray plate of Example 3 having a DLC film thickness of 5 μm and the spray plate (base) of Comparative Example 3 were subjected to the spray test apparatus 30 and the spray test was performed for 50 hours. The results are shown in Table 2 below.

According to Table 2, the spray plate of Example 3 with DLC coating (film thickness 5 μm) had a spray rate increase rate of 1.0%, whereas the spray plate (base) of Comparative Example 3 had 2 It was 0.0%, and the rate of increase was twice the same as that of the jet plate of Example 1, and wear of the spray port of the jet plate (substrate) was large. After the test, when the surface of the ejection plate of Example 3 was observed with the naked eye, peeling of the DLC film was not confirmed.
Furthermore, the end surfaces of the spray ports of the spray plate of Example 3 and the spray plate (substrate) of Comparative Example 3 after the spray test were observed with a scanning electron microscope at a magnification of 500 times. The obtained micrograph is shown in FIG. According to the photomicrograph of FIG. 8, the surface of the jet plate (substrate) of Comparative Example 3, which was untreated, was worn by the aqueous calcium carbonate solution after the spray test, as shown in FIG. 8 (b). On the other hand, as shown in FIG. 8 (a), the nozzle plate of Example 3 to which DLC coating was applied did not show significant deterioration on the surface of the end face of the spray port even after the spray test, and the DLC film remained. It was confirmed that

Subsequently, the spray plate of Example 2 having a DLC film thickness of 3 μm and the spray plate (base) of Comparative Example 2 were subjected to the spray test apparatus 30 and diluted 80 times as in the spray plates of Examples 1 and 3. The calcium carbonate aqueous solution was sprayed for 100 hours, and then, as an accelerated test, a spray test was further conducted for 100 hours using the calcium carbonate aqueous solution concentrated at a dilution ratio of 40 times for a total of 200 hours. The results are shown in Table 3 below and FIG.

According to Table 3 and FIG. 7, the spray plate (base body) of Comparative Example 2 had a spray rate change rate of 4.6%, whereas the spray plate of Example 2 with DLC coating (film thickness 3 μm) ) Was 1.0%, it can be seen that the jet plate of Example 2 has high wear resistance and good durability even after a severe acceleration test. In addition, it was not possible to visually confirm the peeling of the DLC film in the jet plate of Example 2.

“Peeled stainless steel spray plate”:
Plasma ion implanter (Kurita Manufacturing Co., Ltd.) for two spray plates made of stainless steel (SUS 304) with a diameter of 15 mm and a thickness of 0.5 mm and having a conical section with a diameter of 10 mm and a height of 5 mm with a spray port at the tip. DLC coating was performed at a pressure of 0.7 Pa. At that time, a negative bias voltage of minus 15 kV was applied to one (Comparative Example 4) using acetylene as a film forming material, and a negative 3 kV pulse bias voltage was applied to the other (Comparative Example 5) using acetylene as a film forming material. Was applied constantly, and each was subjected to DLC coating treatment. When the film thickness of the DLC film on the surface of the spray plate substrate was estimated by the same method as in Example 1, all were 3 μm.

Then, the spray test shown in Example 5 was performed for both for 10 hours, and after the spray test was finished, each jet plate was photographed from the bottom surface (back surface) side. The imaging results are shown in FIG. As a result, as shown in FIG. 9A, the jet plate to which a pulse bias voltage of minus 3 kV is applied wears the DLC film due to the calcium carbonate aqueous solution, and the upper half of the DLC film is peeled off. The exposure of the stainless steel as the base 4Z of the substrate was confirmed. On the other hand, as shown in FIG. 9B, the jet plate to which a pulse bias voltage of minus 15 kV is applied has a DLC film of about one third of the upper side of the photograph peeled off to expose the base 4Z, and the remaining DLC film There were wrinkles and cracks due to residual stress. On the other hand, the jet plate of Example 2 appropriately coated with DLC was subjected to a 200-hour spray test according to Example 5, but no DLC film peeling was observed as shown in FIG. 9C. .

Since the jet plate according to the present invention is excellent in corrosion resistance and wear resistance, it can be used for outdoor applications including agricultural houses in addition to indoor applications. Uniform spraying can be performed over a long period of time by improving the durability of the nozzle. Therefore, when it is used as a moisture / nutrient dispersing cloth in a plant factory plant, the maintenance cost required for replacement can be reduced.

DESCRIPTION OF SYMBOLS 1,1a Spray plate 2,2a Spray plate base | substrate 3 Peripheral plate part 3A Bottom face 4 Conical part 4A Concave part 5 Spray port 6 DLC film 10, 10a Spray nozzle 20 Plasma ion implantation apparatus 24 High frequency power supply 25 Pulse bias power supply

Claims (6)

A method for producing a spray plate, in which a diamond-like carbon film is formed on a surface of a spray plate substrate having a spray port by a plasma ion implantation method,
In the plasma ion implantation method, an intermediate layer forming step for forming an intermediate layer on the surface of the injection plate substrate by adding a silicon gas gasified by heating while applying a pulse bias voltage of minus 10 kV; By applying a pulse bias voltage in the presence of a hydrocarbon gas that is a film forming raw material to the jet plate substrate on which the intermediate layer has been formed by the intermediate layer forming step , plasma is generated around the jet plate substrate, Comprising ion implantation and film-forming steps for injecting ions in plasma into a nozzle plate substrate and forming a diamond-like carbon film on the surface of the nozzle plate substrate;
A method for producing a jet plate, wherein the ion implantation and film forming steps are performed while changing a pulse bias voltage from −15 kV to −3 kV to a high-frequency power source.
The spray plate substrate is composed of a peripheral plate portion and a conical recess portion formed by indenting upward from the bottom surface of the peripheral plate portion, and a spray port is formed through the top portion of the conical recess portion. 2. A method for producing a spout plate according to claim 1, wherein: 噴板method according to claim 1 or any one of claims 2 thickness of the diamond-like carbon film is equal to or is 0.5μm or more 5μm or less. 噴板method according to any one of claims 1 to 3, characterized in that噴板substrate is made of stainless steel. 噴板method according to any one of claims 1 to 3, characterized in that噴板substrate is made of a synthetic resin. 6. The method of manufacturing a spray plate according to claim 1, wherein the spray plate is used for an agricultural spray nozzle.

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