JPH08337874A - Substrate surface coating layer and its forming method, heat exchanger fin and its manufacturing method. - Google Patents

Abstract

PURPOSE: To form a base material surface coated layer having water repellency and durability by forming a diamond like carbon layer on the surface of a base material and reforming the upper part of the layer into a fluorine- containing carbon layer controlled in F/C value on the outermost surface and having C-F bond. CONSTITUTION: A fine ruggedness about 2μm in centerline average surface roughness is formed by spraying a powdery alumina on the surface of a base material 1 (stainless steel or the like). The diamond like carbon layer 2 (DLC layer) is deposited and formed with 100-500nm thickness on the surface of the sprayed material 1 by using the plasma of a hydrocarbon based gas (CH4 gas or the like) as a raw material. Next, RF bias voltage of -150V to -60V is impressed to the base material 1 and, in this state, the surface of the DLC layer 2 is irradiated with the plasma of the fluorine-containing gas to reform the upper part of the layer into the fluorine-containing carbon layer >=0.55 preferably <=0.9 in the ratio (F/C) of the atomic numbers of fluorine to carbon on the outermost layer and having C-F bond.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a base material surface coating layer having excellent water repellency and durability, a method for forming the same, and
The present invention relates to a heat exchanger fin and a manufacturing method thereof.

[0002]

2. Description of the Related Art When water-repellent treatment is applied to the surfaces of cooking utensils such as frying pans and hot plates, water and oil are repelled and dirt easily falls off. Also, if a water-repellent function is added to the inner surface of pipes that are extensively used in chemical plants, the resistance and waste of the fluid flowing through the pipes will be reduced, cost will be reduced, and efficiency will be greatly improved. Is desired.

The fins of heat exchangers used in air conditioners and refrigerators are also good examples where water repellent treatment is desired. That is, dew easily attaches to the fins that have the function of drawing heat from the outside and warming the refrigerant gas. When this dew changes frost and forms frost, the frost blocks the flow of air, heat exchange cannot be performed smoothly, and the cooling / heating capacity drops sharply. Therefore, in order to prevent such frost formation, the surface of the fin of the heat exchanger is also subjected to water repellent treatment. As described above, there is a great need for subjecting the surface of the base material to the water-repellent treatment, that is, making the surface of the base material a water-repellent surface.

Conventionally, Teflon treatment (trade name of DuPont) is well known as a method for treating the surface to be water-repellent. It is a method of coating a solution containing polytetrafluoroethylene on the surface of an object and heat-treating it at about 350 ° C to coat the surface. Due to its excellent water repellency and lubricity, it is widely applied to the inner surface of frying pans. There is.

[0005]

When the Teflon treatment is applied to the coating of the inner surface of a frying pan or the heating plate of a hot plate, the strength of the coating layer (coating layer) obtained is weak, so that a metal spatula or rhododendron should be removed. It cannot be used for cooking used. In other words, since it is damaged or peeled off due to strong contact or friction, only wooden or plastic spatula or shakushi can be used. Further, there is also a problem that a high temperature treatment is required for forming the coating layer (coating layer), so that the constituent material of the applicable substrate is greatly limited.

Further, the fin for the heat exchanger has a plate thickness of 0.1 mm.
It is composed of a thin aluminum plate. Therefore, the deformation,
Deterioration is likely to occur, and the deformation and alteration become remarkable after the high temperature process for the Teflon treatment. Therefore, it is difficult to apply the above-mentioned Teflon treatment (processing) which requires high temperature treatment for the water repellent treatment of the fins. Further, even if the Teflon treatment can be performed, the Teflon layer has a low thermal conductivity, so that there is a problem that the heat transfer function inherent to the fin is impaired.

Therefore, recently, a method of treating the carbon layer with fluorine plasma has been reported as a method capable of treating at a lower temperature, and the modified surface thereof is often evaluated. However, in the surface of the carbon layer modified by the fluorine plasma treatment, since the penetration of fluorine into the surface of the carbon layer is not strong, the water repellency is changed over time, and there is a problem in durability. Further, since the strength is insufficient, there is a problem that the water repellency of the surface is impaired by strong friction.

As described above, in the conventional water-repellent treatment of the substrate surface, the substrate surface is modified so that both the mechanical strength and the water-repellent performance are excellent, that is, the substrate surface is mechanically treated. It is difficult to form a coating layer that is excellent in both dynamic strength and water repellency, and the treatment temperature at that time is high, so the constituent material of the base material is greatly limited. Have

The present invention has been made to solve the above-mentioned conventional problems, and provides water repellency (durability) in which excellent water repellency is maintained for a long time and high mechanical strength. An object is to provide a base material surface coating layer having the same and a method for forming the same.

Another object of the present invention is to have water repellency (durability) in which excellent water repellency is maintained for a long period of time and high mechanical strength, and this high mechanical strength is maintained for a long period of time. It is an object of the present invention to provide a base material surface coating layer and a method for forming the same.

Still another object of the present invention is to provide a heat exchanger filter in which heat exchange is smoothly carried out for a long period of time and cooling and temperature raising capabilities do not drop sharply, and a method for manufacturing the same.

[0012]

A base material surface coating layer according to the present invention comprises a diamond-like carbon layer formed on the surface of a base material and the number of fluorine atoms on the outermost surface formed on the diamond-like carbon layer. And a fluorine-containing carbon layer having a C—F bond having a carbon atom number ratio (F / C value) of 0.55 or more.

Further, in the above structure, it is preferable that the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer is 0.9 or less.

Further, in the above structure, the fluorine-containing carbon layer has a ratio (F / C value) of the number of fluorine atoms and the number of carbon atoms sequentially from the interface with the diamond-like carbon layer toward the outermost surface thereof. It is preferably increased.

Further, in the above structure, the surface of the base material has minute irregularities, and the outermost surface of the fluorine-containing carbon layer has minute irregularities corresponding to the minute irregularities of the surface of the substrate. Is preferably provided.

Further, in the above-mentioned structure, it is preferable that the base material is a metallic substrate composed mainly of at least one selected from stainless steel, aluminum, titanium, nickel and copper.

In the above structure, the diamond-like carbon layer has a thickness in the range of 100 to 5000 nm, and the fluorine-containing carbon layer has a thickness of 5 to 200 nm.
It is preferably in the range of.

Next, the method for forming a base material surface coating layer according to the present invention comprises depositing and forming a diamond-like carbon layer on the base material surface using plasma of hydrocarbon gas as a raw material,
An RF bias voltage having a voltage value in the range of −150 V to −60 V is applied to the base material, and in this state, the surface of the diamond-like carbon layer is irradiated with plasma of a fluorine-containing gas to form the diamond-like carbon. The upper part of the carbon layer is C
It is for modifying to a fluorine-containing carbon layer having a -F bond.

Further, in the above structure, the hydrocarbon-based gas plasma is supplied to the reaction chamber in which the base material is arranged and the diamond-like carbon layer is formed on the surface of the base material. It is preferable to generate by introducing gas and plasma of an inert element gas generated in the plasma generation chamber.

Further, the method for forming the base material surface coating layer according to the present invention is such that a diamond-like carbon layer is deposited and formed on the surface of the base material by using hydrocarbon gas plasma as a raw material,
An RF bias voltage having a voltage value in the range of −240 V to −60 V is applied to the base material, and in this state, plasma of a hydrocarbon-based gas and plasma of a fluorine-containing gas are used as raw materials to produce the diamond-like carbon. A fluorine-containing carbon layer having a C—F bond is deposited and formed on the layer.

In the above structure, it is preferable to continuously form the diamond-like carbon layer and the fluorine-containing carbon layer in the reaction chamber maintained under reduced pressure.

Further, in the above-mentioned structure, the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber is sequentially increased to increase the fluorine-containing carbon. Preference is given to forming layers.

Further, in the above structure, it is preferable that the inside of the reaction chamber is filled with only the fluorine-containing gas when the formation of the fluorine-containing carbon layer is completed. Further, in the above structure, it is preferable that the surface of the base material has minute irregularities.

Next, in the heat exchanger fin according to the present invention, the heat transfer tubes through which the refrigerant flows are inserted into the through holes at the positions corresponding to each other of the plurality of metal thin plates each having the plurality of through holes. , Adjacent two of the metal sheets
In a heat exchanger fin in which a gap for air flow is formed between two metal thin plates, diamond-like carbon layers are formed on the first and second main surfaces of the metal thin plates,
On this diamond-like carbon layer, the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface is 0.55.
The above is characterized in that the fluorine-containing carbon layer having a C—F bond is formed.

In the above structure, it is preferable that the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer is 0.9 or less.

Further, in the above structure, the fluorine-containing carbon layer has a ratio (F / C value) of the number of fluorine atoms and the number of carbon atoms sequentially from the interface with the diamond-like carbon layer toward the outermost surface thereof. It is preferably increased.

Further, in the above structure, the first and second main surfaces of the metal thin plate have minute irregularities,
It is preferable that minute irregularities are formed on the outermost surface of the fluorine-containing carbon layer corresponding to the minute irregularities of the first and second main surfaces of the thin metal plate.

Next, a method for manufacturing a heat exchanger fin according to the present invention is a method for manufacturing the heat exchanger fin, wherein the metal thin plate is placed in a reaction chamber, and the first metal thin plate is used. And a diamond-like carbon layer is deposited and formed on the second main surface by using the plasma of the hydrocarbon gas as a raw material, and then the voltage value of the diamond-like carbon substrate is -150.
An RF bias voltage in the range of V to -60 V is applied, and in this state, the surface of the diamond-like carbon layer is irradiated with plasma of a fluorine-containing gas, and the upper layer portion of the diamond-like carbon layer is exposed to CF. The method is characterized by including a step of modifying the fluorine-containing carbon layer having a bond.

Further, a method for manufacturing a heat exchanger fin according to the present invention is a method for manufacturing the heat exchanger fin, wherein the thin metal plate is arranged in a reaction chamber, and a plasma of a hydrocarbon gas is generated. After forming a diamond-like carbon layer on the first and second main surfaces of the metal thin plate as a raw material, the voltage value of the metal thin plate is -240 V to -60 V.
An RF bias voltage in the range of V is applied, and in this state, using a plasma of a hydrocarbon-based gas and a plasma of a fluorine-containing gas as raw materials, a fluorine-containing carbon layer having a C—F bond on the diamond-like carbon layer. Is characterized by including a step of depositing.

Further, in the above-mentioned structure, the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber is gradually increased to contain the fluorine-containing gas. It is preferable to form a carbon layer.

Further, in the above structure, it is preferable that the inside of the reaction chamber is filled with only the fluorine-containing gas when the formation of the fluorine-containing carbon layer is completed. Further, in the above-mentioned structure, after pressing the metal thin plate with a mold having fine irregularities formed on its surface to transfer the fine irregularities to the first and second main surfaces of the metal thin plate, It is preferable to form the diamond-like carbon layer and the fluorine-containing carbon layer.

Further, in the above structure, it is preferable that the mold has a punching portion for forming a through hole in the thin metal plate during the pressing. Further, in the above structure, the first and second side walls facing each other are provided with the first opening and the second opening for introducing the plasma therein, respectively, in the intermediate portion in the reaction chamber. A metal thin plate is arranged, and the plasma of the hydrocarbon-based gas and the plasma of a fluorine-containing gas introduced from the first opening and the second opening are used as raw materials to produce the first and second metal thin plates. It is preferable to simultaneously form the diamond-like carbon layer and the fluorine-containing carbon layer on the main surface.

Further, in the above structure, it is preferable that the base material is a metal heating plate on which cooking is performed on the surface of the cooking utensil. In the above, "diamond-like carbon layer (DLA layer)"
Means a crystal structure in which carbon atoms are covalently bonded by an sp ³ hybrid orbital, that is, an amorphous hard carbon layer partially containing a diamond type structure, and the “fluorine-containing carbon layer” is a diamond-like carbon layer. And a fluorine atom introduced by C—F bond.

[0034]

According to the constitution of the base material surface coating layer of the present invention described above, the diamond-like carbon layer formed on the surface of the base material and the number of fluorine atoms on the outermost surface formed on the diamond-like carbon layer Ratio of number of carbon atoms (F
/ C value) is 0.55 or more, and the fluorine-containing carbon layer having a C—F bond is used, so that the diamond-like carbon layer is extremely hard with a hardness of 3000 (micro Vickers hardness) or more. , Fluorine on the surface of this extremely hard diamond-like carbon layer
Since the fluorine-containing carbon layer having a low surface energy, which is contained by the -F bonding, is formed, a base material surface coating layer having excellent water repellency and high mechanical strength can be obtained. . In particular, when the ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) is 0.55 or more on the outermost surface of the fluorine-containing carbon layer, excellent water repellency is maintained for a long period of time, and it has durability. It becomes a water repellent surface.

As a preferred example of the above-mentioned constitution, when the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer is 0.9 or less, the outermost surface of the fluorine-containing carbon layer is Can be maintained at a high hardness.

As a preferred example of the above structure, the fluorine-containing carbon layer is a ratio (F / C value) of the number of fluorine atoms and the number of carbon atoms from the interface with the diamond-like carbon layer toward the outermost surface thereof. Is gradually increased, it is possible to reduce the difference in thermal expansion coefficient and the difference in internal stress between the fluorine-containing carbon layer and the diamond-like carbon layer, and it is possible to further improve water repellency and high mechanical strength. it can.

Further, as a preferred example of the above-mentioned constitution, the surface of the base material has minute irregularities, and the outermost surface of the fluorine-containing carbon layer has minute irregularities corresponding to the minute irregularities of the surface of the substrate. When formed, the adhesion tension between the surface of the base material and the water droplets can be further reduced, and the water repellent performance can be further improved.

As a preferred example of the above structure, when the base material is a metal substrate composed mainly of at least one selected from stainless steel, aluminum, titanium, nickel and copper, the surface is excellent in water repellency. The base material has high performance and high mechanical strength and excellent thermal conductivity, and is useful as a constituent material of various devices.

As a preferred example of the above-mentioned constitution, the diamond-like carbon layer has a thickness of 100 to 5000 nm.
And the thickness of the fluorine-containing carbon layer is 5 to
When the thickness is in the range of 200 nm, the adhesion between the two overlapping layers of the base material, the diamond-like carbon layer, and the fluorine-containing carbon layer can be stabilized, which is preferable.

Next, according to the method for forming a base material surface coating layer of the present invention described above, a diamond-like carbon layer is deposited and formed on the surface of the base material using plasma of a hydrocarbon gas as a raw material, and then the base material is formed. An RF bias voltage having a voltage value in the range of −150 V to −60 V is applied to the material, and in this state, the surface of the diamond-like carbon layer is irradiated with plasma of a fluorine-containing gas to form the diamond-like carbon layer. By modifying the upper layer part of the above to a fluorine-containing carbon layer having a C—F bond, the above-mentioned base material surface coating layer having excellent water repellency and high mechanical strength, which is maintained for a long period of time, is reproduced. It can be formed with good properties.

Further, as a preferred example of the above-mentioned constitution, the plasma of the hydrocarbon gas is subjected to the carbonization in a reaction chamber in which the base material is arranged and the diamond-like carbon layer is formed on the surface of the base material. It is preferable that the hydrogen-based gas and the plasma of the inactive element gas generated in the plasma generation chamber are introduced to generate the carbon, and the carbon film does not adhere to the plasma generation chamber, so that the apparatus can be operated stably.

Furthermore, according to the method for forming a base material surface coating layer of the present invention described above, a diamond-like carbon layer is deposited and formed on the surface of the base material using plasma of hydrocarbon gas as a raw material, and then the base material is formed. RF bias voltage whose voltage value is in the range of −240 V to −60 V is applied to the diamond-like carbon layer by using hydrocarbon gas plasma and fluorine gas plasma as raw materials. , C-
By depositing and forming a fluorine-containing carbon layer having an F bond, the base material surface coating layer having the above-mentioned excellent water repellency and high mechanical strength, which is maintained for a long period of time with good reproducibility and high efficiency. Can be formed.

Further, as a preferable example of the above-mentioned constitution, when the diamond-like carbon layer and the fluorine-containing carbon layer are continuously formed in a reaction reaction chamber maintained under reduced pressure, the diamond-like carbon layer and the fluorine-containing carbon layer are formed. The intermediate layer containing oxygen is not formed between the carbon layers, and the base material surface coating layer having high mechanical strength can be stably formed.

Further, as a preferred example of the above-mentioned constitution, the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber is sequentially increased to the above When the fluorine-containing carbon layer is formed, the difference in the coefficient of thermal expansion between the fluorine-containing carbon layer and the diamond-like carbon layer and the difference in the internal stress are alleviated, and the water repellent performance and the high mechanical strength are further improved. The surface coating layer can be reasonably formed.

Further, as a preferable example of the above-mentioned constitution, when the formation of the fluorine-containing carbon layer is completed, if the inside of the reaction chamber is made to contain only the fluorine-containing gas, fluorine is efficiently taken into the outermost surface of the fluorine-containing carbon layer, and it is ensured. The substrate surface coating layer can be modified to have excellent water repellency.

As a preferred example of the above-mentioned constitution, when the surface of the substrate has minute irregularities, minute irregularities corresponding to the minute irregularities on the substrate surface are developed on the outermost surface of the fluorine-containing carbon layer. Then, it is possible to form a base material surface coating layer having further improved water repellency.

Next, according to the structure of the heat exchanger fin of the present invention, the heat transfer tubes through which the refrigerant flows have the through holes at the positions corresponding to each other of the plurality of thin metal plates each having the plurality of through holes. A fin for a heat exchanger, wherein the fins are inserted into a plurality of metal thin plates and a gap for air flow is formed between two adjacent metal thin plates, and a diamond is provided on the first and second main surfaces of the metal thin plates. -Like carbon layer is formed, and the ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) on the outermost surface of the diamond-like carbon layer
By forming a fluorine-containing carbon layer having a C—F bond with a ratio of 0.55 or more, the thin metal plate has the excellent water repellency and high mechanical strength, which is maintained for a long period of time. It has a surface coating layer,
A heat exchanger fin in which air flows smoothly without frost formation can be obtained. Further, since the surface coating layer has a high heat conductivity, a heat exchanger fin having a high heat transfer function can be obtained.

Further, as a preferred example of the above constitution, when the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer is 0.9 or less, the outermost surface of the fluorine-containing carbon layer is Is maintained at high hardness and has extremely high mechanical strength.

As a preferred example of the above structure, the fluorine-containing carbon layer has a ratio (F / C value) of the number of fluorine atoms and the number of carbon atoms from the interface with the diamond-like carbon layer toward the outermost surface thereof. The water repellent performance and the mechanical strength of the surface coating layer can be further improved by increasing the number of the heat treatments, and a higher performance fin for heat exchanger can be obtained.

As a preferred example of the above structure, the first and second main surfaces of the metal thin plate have fine irregularities, and the first surface of the metal thin plate is provided on the outermost surface of the fluorine-containing carbon layer. When the minute irregularities corresponding to the minute irregularities on the second main surface are formed, the metal thin plate has more excellent water repellency and a higher performance fin for heat exchanger can be obtained. .

Next, according to the method for manufacturing a heat exchanger fin of the present invention, there is provided a method for manufacturing the heat exchanger fin, wherein the metal thin plate is placed in a reaction chamber, and the metal thin plate After depositing a diamond-like carbon layer on the first and second main surfaces using the plasma of the hydrocarbon gas as a raw material, the voltage value thereof is -150 on the metal thin plate base material.
An RF bias voltage in the range of V to -60 V is applied, and in this state, the surface of the diamond-like carbon layer is irradiated with plasma of a fluorine-containing gas, and the upper layer portion of the diamond-like carbon layer is exposed to CF. By including the step of reforming into a fluorine-containing carbon layer having a bond, the air can smoothly flow without the above-mentioned frost formation, and the fin for heat exchanger having a high heat transfer function can be reasonably manufactured. You can

Further, according to the method for producing a heat exchanger fin of the present invention, the method for producing the heat exchanger fin is characterized in that the metal thin plate is arranged in the reaction chamber, and After a diamond-like carbon layer is deposited and formed on the first and second main surfaces of the metal thin plate by using plasma as a raw material, the voltage value of the metal thin plate is -240.
An RF bias voltage in the range of V to -60 V is applied, and in this state, fluorine having a C—F bond is formed on the diamond-like carbon layer by using plasma of hydrocarbon gas and plasma of fluorine-containing gas as raw materials. By including the step of depositing and forming the contained carbon layer, it is possible to rationally manufacture the heat exchanger fin having a high heat transfer function, in which air smoothly flows without frost formation.

Further, as a preferable example of the above structure, the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber is gradually increased to the above. When the fluorine-containing carbon layer is formed, it is possible to rationally manufacture a high-performance heat exchanger fin in which the water-repellent performance and mechanical strength of the surface coating layer of the metal thin plate are further improved.

Further, as a preferable example of the above-mentioned constitution, when the formation of the fluorine-containing carbon layer is completed and the inside of the reaction chamber is filled with only the fluorine-containing gas, fluorine is efficiently taken into the outermost surface of the fluorine-containing carbon layer, and it is ensured. The surface coating layer has excellent water repellency, the air flows smoothly without frost formation, and
The heat exchanger fin having a high heat transfer function can be manufactured reasonably and efficiently.

Further, as a preferred example of the above structure, the metal thin plate is pressed by a mold having fine irregularities formed on the surface thereof to form fine irregularities on the first and second main surfaces of the metal thin plate. When the diamond-like carbon layer and the fluorine-containing carbon layer are formed after transfer formation, minute irregularities on the first and second main surfaces of the metal thin plate can be efficiently formed, and the maximum amount of the fluorine-containing carbon layer It is possible to efficiently manufacture a heat exchanger fin having fine water-repellent properties and having excellent water repellency.

Further, as a preferred example of the above-mentioned constitution, when the die has a punching portion for forming a through hole in the metal thin plate at the time of the press working, the heat transfer tube is inserted into the metal thin plate. Since the through hole can be formed during the press working, the manufacturing efficiency can be further improved.

Further, as a preferred example of the above-mentioned constitution, in a reaction chamber in which first and second openings for introducing plasma are formed in the first and second side walls facing each other, respectively. The metal thin plate is disposed in the middle part of the metal thin plate, and the plasma of the hydrocarbon-based gas and the plasma of the fluorine-containing gas introduced from the first opening and the second opening are used as the raw materials. When the diamond-like carbon layer and the fluorine-containing carbon layer are simultaneously formed on the first and second main surfaces, the surface coating layer having the excellent water repellency on the first and second main surfaces of the metal thin plate in a short time. Can be formed, and manufacturing efficiency can be improved.

As a preferred example of the above-mentioned constitution, when the base material is a metal heating plate on which cooking is performed on the surface of the cooking utensil, a metal heating plate capable of using a metal spatula or a rhododendron is used. It is possible to obtain the provided cooking utensil.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view showing the structure of a surface coating layer for coating the surface of a substrate according to Embodiment 1 of the present invention. Surface 4
A diamond-like carbon layer (hereinafter referred to as a DLC layer) 2 and a fluorine-containing carbon layer 3 having a C—F bond are laminated in this order on the surface of a substrate 1 having minute irregularities, and a fluorine-containing carbon layer 3 is formed. In the outermost surface 5, the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms is 0.55 or more.

The first forming method for forming the surface coating layer of FIG. 1 will be described below. FIG. 3 is a diagram showing a schematic configuration of a processing apparatus applied to the first forming method. A plasma generation chamber 23 is attached to a processing chamber (reaction chamber) 22 to which the exhaust system 21 is connected. The plasma generating chamber 23 has a first
A gas is supplied from the gas introduction system 24 and a microwave of 2.45 GHz is supplied from the microwave power generator 25.
Further, the interaction between the magnetic field from the solenoid coil 26 installed around the plasma generation chamber 23 and the microwave causes electron cyclotron resonance (ECR) to cause the plasma generation chamber
Plasma 27 is generated at 23. Substrate 1 in processing chamber 22
Is installed and the plasma 27 from the plasma generation chamber 23 is irradiated. An RF bias voltage is supplied from the RF power source 28 to the substrate 1.

Substrate 1 is made of stainless steel, and fine irregularities having a center line average surface roughness of 2 μm are formed on the surface by spraying alumina powder. First gas introduction system 24
Ar gas is introduced from above, and a second gas introduction system is provided above the substrate 1.
29 is arranged, and CH ₄ gas which is a raw material of the DLC layer 2 is introduced. Ar gas was supplied at a flow rate of 10 sccm, CH ₄ gas was supplied at a flow rate of 20 sccm, and the pressure in the processing chamber 22 was set to ⁴ × 10 ⁻⁴ Torr. A microwave power of 25 W is applied from the microwave power generator 25 to generate ECR plasma of Ar, and CH ₄ gas as a raw material gas is decomposed and synthesized to form the DLC layer 2 on the substrate 1.

The substrate 1 is supplied with an RF bias voltage from the RF power source 28. FIG. 4 shows the potential of the substrate 1. A negative self-bias voltage is generated in the substrate 1 by applying the RF voltage. The voltage Va between the average potential and the ground potential at this time is called the RF bias voltage. Here, the DLC layer 2 was deposited with an RF bias voltage of -120V. The film thickness is 500 nm. When the hardness of the DLC layer 2 was measured with a micro Vickers hardness meter, it was 3300, and it was confirmed that the DLC layer 2 was a high hardness thin film. In the above, by introducing CH ₄ gas from the second gas introduction system 24,
The CH ₄ gas plasma is generated in the processing chamber 22 by receiving the energy generated by the Ar gas plasma generation. However, the CH ₄ gas is directly introduced from the first gas introduction system 24 to generate the plasma generation chamber 23. A similar hard DLC layer 2 can be obtained by generating a plasma of CH ₄ gas in the chamber and introducing it into the processing chamber (reaction chamber) 22. However, in this case, the carbon film adheres to the inside of the plasma generation chamber 23, which causes a decrease in the operating efficiency of the device.

After forming the DLC layer 2, the first gas introduction system
Only CH ₄ gas is introduced from 24 and the pressure in the processing chamber 22 is increased.
Plasma containing fluorine as ⁴ × 10 ⁻⁴ Torr is generated and irradiated on the surface of the DLC layer 2. At this time, no gas is introduced from the second gas introduction system 29. RF bias voltage of -100V is applied to the substrate 1 to increase the energy of plasma,
The surface of the DLC layer 2 on the substrate was irradiated with this, and the upper layer portion thereof was modified into the fluorine-containing carbon layer 3 having a thickness of 20 nm. Figure 5
Is the result of evaluating the water repellency of the modified surface (5) thus treated with plasma by the contact angle of water. DL before modification
The contact angle of C layer 2 alone is as low as about 70 °, but the contact angle is rapidly increased by performing the above plasma treatment, and the contact angle is about 1 °.
Saturated at 25 ° and modified to a highly water repellent surface. Here, the RF bias voltage is set to -100V, but even if various other RF bias voltages are applied and the same plasma irradiation is performed, the water repellent characteristics of the modified surface are similar to those in FIG. There is.

FIG. 6 shows the results of examining how the contact angle changes with time.
It is the result of examining the aging characteristics for 1000 hours or more under a normal environment with a humidity of 45%. The following significant differences were found in the characteristics.
A decrease in contact angle is seen when the negative RF bias voltage is 0V and 40V, but by increasing it to 60V or more (a decrease in contact angle is seen when the RF bias voltage is 0V and -40V, but -60V By the following), almost no change in the contact angle with time is observed, and the water repellent surface has high durability. Such a water-repellent surface is subjected to X-ray photoelectron spectroscopy (X
FIG. 7 shows the result of observation by PS) and analysis of the spectrum. CF in the spectrum, which peaks appear in CF _2, CF _3, it was confirmed that CF bond is formed modified layer.

FIG. 8 shows the result of X-ray photoelectron spectroscopy (XPS) analysis of the composition of the modified surface (5) obtained by plasma-treating the DLC layer 2 with the RF bias voltage as a parameter. The vertical axis shows the ratio F / C value of the number of fluorine atoms and the number of carbon atoms as the composition. As the RF bias voltage is increased, the F / C value rises, promoting fluorination of the DLC layer. In the time-dependent characteristics of the contact angle in FIG. 6, a water-repellent surface that does not change with time is obtained by applying a negative RF bias voltage of 60 V or more (by applying an RF bias voltage of -60 V or less). In the composition of FIG. 8, the negative RF bias voltage is 60V (the RF bias voltage is -60V).
The F / C value is 0.55. That is, it has been found here that a water-repellent surface having an F / C value of 0.55 or more as the composition of the modified surface and having excellent durability is provided.

FIG. 9 shows the results of measuring the hardness of the modified surface subjected to the plasma treatment with a micro Vickers hardness meter using the RF bias voltage as a parameter. Before plasma treatment,
That is, the hardness of the DLC layer 2 is 3300 as described above,
When the negative RF bias voltage is 150 V or less (RF bias voltage is -150 V or more), the hardness does not change even after fluorination, but when it exceeds 150 V (the RF bias voltage becomes smaller than -150 V) A decrease in hardness is seen. The composition on the outermost surface when treated with a bias voltage of −150 V is 0.9 as shown in FIG. 7, and therefore a large amount of fluorine enters the modified surface, which results in a strong bond between Cs (C—C) in the DLC layer 2. Binding). FIG. 10 shows the results of measuring the etching depth in the DLC layer 2 when plasma processing was performed using the RF bias voltage as a parameter. Although the etching amount is gradually increased due to the influence of the high-energy ions due to the increase of the negative RF bias voltage, when the negative RF bias voltage is set higher than 150 V (when the RF bias voltage is set lower than -150 V, ), Due to its energy D
The etching amount of the LC layer 2 rapidly increases, leading to the thinning of the DLC layer 2 as a hard layer, which is not suitable. For this reason,
It is important that the RF bias voltage be in the range -60V to -150V. The RF bias voltage of −150 V matches the voltage at which the hardness of the modified surface is lowered as shown in FIG. 9, and the inclusion of a large amount of fluorine on the modified surface causes the hardness to decrease and the etching amount to increase. It is believed that this was invited. (Embodiment 2) FIG. 2 is a sectional view showing a structure of a surface coating layer for coating a substrate surface according to Embodiment 2 of the present invention.
And the same reference numeral as 3a, and 3a is C
It is a fluorine-containing carbon layer having a -F bond. The fluorine-containing carbon layer 3a is deposited and formed on the surface of the DLC layer 2, and the outermost surface 5 has a ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) of 0.55 or more.

Next, a method of forming the surface coating layer of this embodiment shown in FIG. 2 will be described below. Using the same apparatus shown in FIG. 2 as the forming method according to the first embodiment, plasma of CH ₄ gas is generated in the plasma generating chamber 23 in the processing chamber 22 as in the forming method of the first embodiment. Then, the DLC layer 2 having a thickness of 500 nm is formed on the surface 4 of the substrate 1 having minute irregularities. And after this,
A mixed gas of CH ₄ gas and CF ₄ gas is introduced into the processing chamber 22 from the second gas introduction system 29, plasma of these CH ₄ gas and CF ₄ gas is generated, and the fluorine-containing carbon layer 3 having a thickness of 50 nm is subjected to DLC. Deposited on layer 2. At this time, the first
Ar gas was supplied from the gas introduction system 24 at 10 sccm, CH ₄ gas was supplied at 20 sccm and CF ₄ gas was supplied at 10 sccm from the second gas introduction system 29, and the pressure in the processing chamber 22 was set to ⁴ × 10 ⁻⁴ Torr. Also,
Input microwave power of 200 W from the microwave power generator 25 to generate ECR plasma of Ar, CH of raw material gas
₄ gas and CF ₄ gas are decomposed and synthesized to generate plasma of these gases. The fluorine-containing carbon layer 3 may be formed by directly introducing CH ₄ gas and CF ₄ gas from the first gas introduction system 24 into the plasma generation chamber 23 and generating plasma of these gases.

Similar to the first embodiment, in this embodiment as well, a negative RF bias voltage is applied to the substrate 1 at the time of forming the fluorine-containing carbon layer 3a, but the negative RF bias voltage is increased. Accordingly, the fluorine-containing carbon layer 3 (3
In the case of a), the hardness is increased by the effect of the ions whose energy is increased by the bias voltage. The water repellency of the surface of the fluorine-containing carbon layer 3 becomes almost zero when the negative RF bias voltage is set to 60 V or more (RF bias voltage is -60 V or less), and the water repellency does not change with time. It is possible to provide a water-repellent surface having a certain property.
In the method of this embodiment, as in the method of the first embodiment, D
Unlike the case where the surface of the LC layer 2 is irradiated with plasma to modify the surface of the DLC layer 2, that is, the upper layer portion thereof into the fluorine-containing carbon layer 3, the fluorine-containing carbon layer 3a is formed on the surface of the DLC layer 2. Are deposited and formed. Therefore,
The etching erosion of the DLC layer 2 found by the method of Example 1 above basically does not occur. However, when the negative RF bias voltage is made higher than 240 V (the RF bias voltage is made lower than -240 V), the film forming ability and the etching ability of the already obtained film are balanced due to the high energy of the ions. Therefore, the deposition rate (deposition rate) of the film of the fluorine-containing carbon layer 3a becomes extremely low, which is not suitable. From the above, in the method of the present embodiment, the RF bias voltage in the formation of the fluorine-containing carbon layer 3a is
It is preferably in the range of -60V to -240V.

In this embodiment, after the DLC layer 2 was formed, the substrate 1 was returned to the atmosphere, and the pressure was reduced again to form the fluorine-containing carbon layer 3a. An intermediary layer is formed, and when this intermediary layer is formed, the adhesion between the DLC layer 2 and the fluorine-containing carbon layer 3a deteriorates, and the strength of the surface coating layer tends to decrease. Therefore, the DLC layer 2 and the fluorine-containing carbon layer 3a are continuously connected in the depressurized processing chamber 22 without returning the substrate 1 to the atmospheric state between the step of forming the DLC layer 2 and the step of forming the fluorine-containing carbon layer 3a. It is preferable to form the film. (Embodiment 3) A surface coating layer for coating the surface of a substrate according to Embodiment 3 of the present invention will be described. The structure of the surface coating layer of Example 3 is basically the same as that of the surface coating layer of Example 2 (see FIG. 2), but the fluorine-containing carbon layer 3a having a C—F bond has the same DLC. The F / C value gradually increases from the interface 6 with the layer 2 toward the outermost surface 5, and the F / C value on the outermost surface 5 is 0.55 or more. In this way, the fluorine-containing carbon layer 3a
By increasing the proportion of fluorine atoms contained from the interface 6 with the LC layer 2 toward the outermost surface 5 thereof, the difference in the thermal expansion coefficient and the difference in the internal stress with the DLC layer 2 as the lower layer are relaxed. Therefore, the mechanical strength of the surface coating layer is further improved.

The method for forming the surface coating layer of this embodiment will be described below. Processing chamber similar to that of Example 2 above
The substrate 1 having minute irregularities 4 on the surface is set in the inside 22, and CH ₄ gas and CF ₄ gas are supplied from the first gas introduction system 24. Figure 11
As shown in period A of (a), the source gas is CH _{4 at the} beginning of film formation.
The plasma is generated only as a gas, and D is generated on the substrate 1.
The LC layer 2 is deposited and formed. At this time, change the flow rate of CH ₄ gas to 20
Supplied as sccm and the pressure in the processing chamber 22 is 4x10 ^-4 Torr
Then, a microwave power of 200 W was applied, a negative RF bias voltage of 120 V was applied to the substrate 1 to generate ECR plasma, and the DLC layer 2 was formed to a film thickness of 500 nm. After that, CF ₄ gas is added to CH ₄ gas, and the partial pressure ratio (partial pressure (CF ₄ ) / partial pressure (CH ₄ )) is obtained as shown in period B of FIG. 11 (a).
Are sequentially increased to form a fluorine-containing carbon layer 3a with a film thickness of 200 nm. At the time of forming the fluorine-containing carbon layer 3a, a negative RF bias voltage is applied to the substrate 1 as in the case of forming the DLC layer 2. However, as the negative RF bias voltage increases, the fluorine-containing carbon layer 3a is biased. The hardness increases due to the effect of the ions whose energy is increased by the voltage. The water-repellent performance of the surface based on the fluorine-containing carbon layer 3a is a durable water-repellent performance with a negative RF bias voltage of 60 V or more and hardly changing with time. But negative R
When the F bias voltage is higher than 240 V, the film forming ability and the etching ability of the film are balanced by increasing the energy of the ions as described above, so that the deposition rate of the fluorine-containing carbon layer 3a becomes extremely small. . From the above, the partial pressure ratio (partial pressure (CF ₄ ) / partial pressure (CH ₄ )) is sequentially changed, and the proportion of fluorine atoms contained from the interface 6 with the DLC layer 2 toward the outermost surface 5 thereof. Also in the case of forming the fluorine-containing carbon layer 3a having an increased amount, the RF bias voltage is preferably in the range of -60V to -240V.

In forming the fluorine-containing carbon layer 3a, as shown in period B of FIG. 11 (b), the partial pressure ratio (partial pressure
(CF ₄ ) / partial pressure (CH ₄ )) is sequentially increased, and the outermost surface is modified with only CF ₄ gas during the C period at the end of layer formation to improve the durability of water repellency. The excellent fluorine-containing carbon layer 3a can be formed. In this way, in the final step of forming the fluorine-containing carbon layer, the raw material gas
When using only CF ₄ gas, RF bias voltage is -60V
It is appropriate to change from the range from -240V to the range from -60V to -150V. This is because when the plasma of CF ₄ alone is irradiated, the etching amount sharply increases when the voltage exceeds −150 V, and thus the fluorine-containing carbon layer formed up to that point may be eroded. (Embodiment 4) FIG. 12 is a diagram showing a structure of a heat exchanger fin according to a fourth embodiment of the present invention, FIG. 12 (a) is a perspective view showing an assembled structure of the heat exchanger fin, and FIG. 12 (b). FIG. 3 is a diagram showing a configuration of a thin metal plate for fins. The heat exchanger fins are assembled by inserting a plurality of heat transfer tubes 46 through which a refrigerant flows into the hole portions 47 of a plurality of fin metal thin plates 41 in which a plurality of hole portions 47 are formed. Minute irregularities are formed on both surfaces 44 of the metal thin plate 41, and a DLC layer 42 and a fluorine-containing carbon layer 43 having a C—F bond are laminated on both surfaces 44.
Here, in the outermost surface 45 of the fluorine-containing carbon layer 43, the ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) is 0.55 or more.

A method for manufacturing the heat exchanger fin of this embodiment will be described below. As shown in FIG. 13, the metal thin plate 41 made of aluminum is pressed by the pressing dies 49 and 50, and the metal thin plate 41 is pressed.
Minute unevenness is formed on the surface of the
A hole portion 47 for inserting 46 is formed. Here, the pressing dies 49, 50 have minute irregularities on the surface thereof, and also have a punching portion 48 for forming the hole portion 47. By pressing such a metal thin plate 41, a large number of fin metal thin plates 41 having fine irregularities on the surface thereof can be manufactured at low cost. After this, a plurality of thin metal plates 41
The heat transfer tube 46 is inserted into each of the plurality of hole portions 47, and the fins for the heat exchanger are assembled.

The basic steps of assembling the heat exchanger fins have been described above. In this embodiment, before the assembling, the processing apparatus shown in FIG. Similarly, a DLC layer 42 is formed on the surface of the metal thin plate 41 made of aluminum, and a fluorine-containing carbon layer 43 having a C—F bond is formed on the DLC layer 42 by modifying the surface of the DLC layer 42 or by plasma deposition. Form. CF ₄
When the surface of the DLC layer 42 is modified by gas plasma to form the fluorine-containing carbon layer 43, it is desirable to apply the RF bias voltage in the range of -60V to -150V.
Further, when the fluorine-containing carbon layer 43 is deposited and formed by the plasma of CH ₄ gas and CF ₄ gas, the RF bias voltage may be applied in the range of -60V to -240V. This makes it possible to form a highly water-repellent surface having durable water repellency and having a ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface 45 of 0.55 or more.

FIG. 14 shows an apparatus for forming a surface coating layer on the surface of a substrate different from that shown in FIG. 3, and it has two plasma generating chambers arranged in the processing chamber 22 so as to face each other. The ECR plasma is simultaneously generated by the interaction of the microwave and the magnetic field in each plasma generation chamber 23, and is connected to both surfaces of the fin metal thin plate 41 arranged in the center of the processing chamber 22. Plasma is irradiated at the same time. An RF power source 28 is connected to the fin thin metal plate 41 to apply an RF bias voltage. By using such an apparatus, the DLC layer 42 and the fluorine-containing carbon layer 43 can be simultaneously formed on both sides of the fin metal thin plate 41, so that the manufacturing time during mass production of heat exchanger fins can be shortened. (Embodiment 5) FIG. 15 is a sectional view showing the structure of a fin metal sheet of a heat exchanger fin according to Embodiment 5 of the present invention.
In the figure, the same reference numerals as those in FIG. 12 (a) indicate the same or corresponding portions, and 43a is a fluorine-containing carbon layer having a C—F bond. In the fluorine-containing carbon layer 3a having the C—F bond, the F / C value gradually increases from the interface 51 with the DLC layer 42 toward the outermost surface 45, and the F / C value at the outermost surface 45 is 0.55 or more. It is one that has become. The formation method of the fluorine-containing carbon layer 3a having the C—F bond is the same as in Example 4 except that the fin thin metal plate 41 is manufactured, and the surface thereof is treated by the same treatment method as in the third embodiment.
42 and a fluorine-containing carbon layer 43a are formed. In addition, when the DLC layer 42 and the fluorine-containing carbon layer 43a are formed,
By using a processing apparatus having two plasma generation chambers 23 as shown in FIG.
Since the layer 42 and the fluorine-containing carbon layer 43a can be formed at the same time, manufacturing efficiency can be improved. (Example 6) Example 6 is an example in which the present invention is applied to a hot plate for cooking. FIG. 16 is a sectional view showing the configuration of the cooking hot plate according to the sixth embodiment, in which the heating plate 61 made of stainless steel is placed on the heater 66 via the support portion 68 of the main body 67 and the temperature controller portion 69. The temperature of the heating plate 61 is controlled. Minute irregularities are formed on the surface 64 of the heating plate 61, and the DLC layer 62 and the fluorine-containing carbon layer 63 having a C—F bond are laminated in this order on this surface. The ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface 65 of the fluorine-containing carbon layer 63 is 0.55 or more. Here, the method of forming the DLC layer 62 and the fluorine-containing carbon layer 63 in this order on the surface of the heating plate 61 is performed in the same manner as that of the above-mentioned embodiment.

In the heating plate 61 for the hot plate of this embodiment, the DLC layer 62 on the surface and the ratio (F / C value) of the number of fluorine atoms and the number of carbon atoms of the outermost surface 65 are 0.55 or more. Since the fluorine-containing carbon layer 63 having a certain C—F bond is laminated in this order and has not only water repellency but also oil repellency, water and oil can be repelled well, and dirt easily falls. In addition, since the DLC layer 62 and the fluorine-containing carbon layer 63 have high hardness, it is possible to cook using a metal spatula or rhododendron, which cannot be used with a conventional one whose surface is treated with Teflon. , Very convenient.

In the above Examples 1 to 6, alumina powder was sprayed on the surface of the substrate to form fine irregularities having a center line average surface roughness (Ra) of 2 μm, but in the present invention, the surface is flat. Even if a simple substrate is used, a DLC layer is formed on this surface,
By forming a surface coating layer in which a fluorine-containing carbon layer having a C—F bond having a ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) on the outermost surface of 0.55 or more is laminated in this order, it is excellent. A water repellent performance is maintained for a long period of time, and a surface having high mechanical strength can be obtained. However, the center line average roughness (Ra) of the substrate surface
Has fine irregularities in the range of 0.1 μm to 5.0 μm, so that the center line average roughness (Ra) of the surface of the obtained substrate surface coating layer is in the range of 0.1 μm to 5.0 μm. Since minute irregularities corresponding to minute irregularities are formed, the gap between the surface of the substrate surface coating layer and water droplets is smaller than that when the substrate surface is flat, that is, when the surface of the substrate surface coating layer is flat. The adhesive tension of is further reduced, and the water repellent performance is further improved.

Further, although CH ₄ gas was used as the raw material gas containing carbon in the above Examples 1 to 6, the present invention is not limited to this, and other gases such as C ₂ H ₆ gas and C ₃ H ₈ gas may be used. An aliphatic hydrocarbon gas or an aromatic hydrocarbon gas such as C ₆ H ₆ (benzene) gas may be used as the source gas.

Although CF ₄ gas was used as the fluorine-containing gas in Examples 1 to 6, other carbon-based gas such as CHF ₃ gas or fluorine-containing sulfur such as SF ₆ gas or NF ₃ gas. The same effect can be obtained by using a system gas or a nitrogen system gas.

Further, although the case where the stainless steel substrate is used has been described in the first to sixth embodiments, the present invention is a substrate mainly composed of a metal other than stainless steel such as aluminum, titanium, nickel and copper. Alternatively, it can be applied to the case of using a substrate made of a material other than metal such as plastic and glass.

Further, although the case where the substrate is used as the base material for forming the surface coating layer has been described in the first to sixth embodiments, the present invention is not limited to the plate-shaped material, but other materials such as a rod-shaped material and a block-shaped material. It can also be applied when a shaped substrate is used.

[0081]

As described above, according to the substrate surface coating layer of the present invention, the diamond-like carbon layer formed on the substrate surface and the outermost surface formed on the diamond-like carbon layer are formed. Since the ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) is 0.55 or more, and the fluorine-containing carbon layer having a C—F bond is used,
The diamond-like carbon layer has a hardness of 3000 (micro Vickers hardness) or more, which is extremely hard, and the surface of this extremely hard diamond-like carbon layer is made to contain fluorine by C--F bonding to form a low surface. Since the fluorine-containing carbon layer having energy is formed, a base material surface coating layer having excellent water repellency and high mechanical strength can be obtained, and in particular, fluorine atoms are formed on the outermost surface of the fluorine-containing carbon layer. Since the ratio of the number of carbon atoms to the number of carbon atoms (F / C value) is 0.55 or more, excellent water repellent performance can be maintained for a long period of time.

Next, according to the method for forming a base material surface coating layer of the present invention, a diamond-like carbon layer is deposited and formed on the surface of a base material using plasma of hydrocarbon gas as a raw material, and then the base material is formed. To the surface of the diamond-like carbon layer by irradiating the surface of the diamond-like carbon layer with plasma of a fluorine-containing gas in this state by applying an RF bias voltage whose voltage value is in the range of −150 V to −60 V. Since the upper layer is modified into a fluorine-containing carbon layer having a C—F bond, it has the above-mentioned excellent water repellency and high mechanical strength,
It is possible to form the base material surface coating layer, which is maintained over a long period of time, with high reproducibility and with high efficiency.

Furthermore, according to the method for forming a base material surface coating layer of the present invention, a diamond-like carbon layer is deposited and formed on the surface of the base material using plasma of hydrocarbon gas as a raw material, and then the base material is formed on the base material. An RF bias voltage having a voltage value in the range of −240 V to −60 V is applied, and in this state, plasma of a hydrocarbon-based gas and plasma of a fluorine-containing gas are used as raw materials on the diamond-like carbon layer, C-F
Since the fluorine-containing carbon layer having a bond is formed by deposition, it has the above-mentioned excellent water-repellent performance and high mechanical strength, and the base material surface coating layer that maintains this for a long time is formed with good reproducibility and high efficiency. can do.

Next, according to the heat exchanger fins of the present invention, the heat transfer tubes through which the refrigerant flows are provided in the through holes at the positions corresponding to each other of the plurality of thin metal plates each having the plurality of through holes. A fin for a heat exchanger, which is inserted and has a gap for allowing air to flow between two adjacent metal thin plates of the plurality of metal thin plates, wherein the first and second main surfaces of the metal thin plates are diamond-shaped. A carbon layer is formed, and the ratio of the number of fluorine atoms to the number of carbon atoms (F / C value) on the outermost surface of the diamond-like carbon layer.
Since the fluorine-containing carbon layer having a C—F bond having a water content of 0.55 or more is formed, the thin metal plate has the excellent water repellency and high mechanical strength described above, and the surface is maintained for a long period of time. With the coating layer, it is possible to obtain a heat exchanger fin in which air flows smoothly without frost formation. Further, since the surface coating layer has a high heat conductivity, it is possible to obtain a heat exchanger fin having a high heat transfer function.

Next, according to the method for manufacturing a heat exchanger fin of the present invention, the metal thin plate is arranged in the reaction chamber, and the hydrocarbon-based gas is provided on the first and second main surfaces of the metal thin plate. After depositing and forming a diamond-like carbon layer using the above plasma as a raw material, an RF bias voltage having a voltage value in the range of −150 V to −60 V is applied to the metal thin plate base material, and in this state, fluorine containing Since the surface of the diamond-like carbon layer is irradiated with gas plasma to modify the upper layer portion of the diamond-like carbon layer into a fluorine-containing carbon layer having a C—F bond, Air flows smoothly without frosting,
Moreover, it is possible to rationally manufacture the heat exchanger fin having a high heat transfer function.

Further, according to the method for manufacturing a fin for a heat exchanger according to the present invention, the thin metal plate is arranged in the reaction chamber, and plasma of hydrocarbon gas is used as a raw material to produce the first and second thin metal plates. After depositing a diamond-like carbon layer on the main surface of No. 2, a voltage value of -24 is applied to the metal thin plate.
Apply an RF bias voltage in the range of 0V to -60V,
In this state, the method includes a step of depositing and forming a fluorine-containing carbon layer having a C—F bond on the diamond-like carbon layer by using hydrocarbon-based gas plasma and fluorine-containing gas plasma as raw materials. It is possible to rationally manufacture the heat exchanger fin having a high heat transfer function, in which air smoothly flows without frost formation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a surface coating layer for coating the surface of a substrate according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a surface coating layer that coats the surface of a substrate according to Example 1 of the present invention.

FIG. 3 is a schematic configuration diagram of a processing apparatus applied to the method for forming the surface coating layer of FIG.

4 is a substrate potential (voltage) when the surface coating layer of FIG. 1 is formed.
It is the figure which showed.

5 is a diagram in which the water repellency of the surface of the fluorine-containing carbon layer surface-modified by the plasma treatment of the surface coating layer of FIG. 1 is evaluated by the contact angle of water.

FIG. 6 is a diagram showing changes with time in water repellency of the surface of the fluorine-containing carbon layer surface-modified by the plasma treatment of the surface coating layer of FIG. 1.

FIG. 7 is a diagram showing the results of spectrum analysis by observing the surface of the fluorine-containing carbon layer surface-modified by plasma treatment of the surface coating layer of FIG. 1 by X-ray photoelectron spectroscopy (XPS).

8 is an RF bias voltage on the DLC layer surface (fluorine-containing carbon layer surface) plasma-treated with the RF bias voltage of the surface coating layer of FIG. 1 as a parameter, and the ratio of the number of fluorine atoms to the number of carbon atoms (F / C). It is the figure which showed the relationship with (value).

FIG. 9 is a diagram showing the relationship between the RF bias voltage of the plasma-treated DLC layer surface (the surface of the fluorine-containing carbon layer) and the hardness with the RF bias voltage of the surface coating layer of FIG. 1 as a parameter.

FIG. 10 is a diagram showing the relationship between the RF bias voltage of the plasma-treated DLC layer surface (fluorine-containing carbon layer surface) and the etching depth using the RF bias voltage of the surface coating layer of FIG. 1 as a parameter.

FIG. 11 is a diagram showing changes in the supply amounts of CH ₄ gas and CF ₄ gas from the start of formation to the end of formation in the step of forming the surface coating layer that covers the surface of the substrate according to Example 3 of the present invention.

FIG. 12 is a diagram showing a structure of a heat exchanger fin according to a fourth embodiment of the present invention, FIG. 12 (a) is a perspective view showing an assembled structure of the heat exchanger fin, and FIG. 12 (b) is a thin metal plate for fins. It is a figure which shows the structure of.

FIG. 13 is a view showing a manufacturing process of the heat exchanger fins according to the fourth embodiment of the present invention.

14 is a schematic configuration diagram of a processing apparatus applied to the method for forming a surface coating layer of the present invention, which has a configuration different from that of the processing apparatus of FIG.

FIG. 15 is a cross-sectional view showing a configuration of a fin metal thin plate of a heat exchanger fin according to a fifth embodiment of the present invention.

FIG. 16 is a cross-sectional view showing the configuration of a cooking hot plate according to Embodiment 6 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 DLC layer 3 Fluorine-containing carbon layer having C-F bond 3a Fluorine-containing carbon layer having C-F bond 4 Substrate surface 5 Outermost surface of fluorine-containing carbon layer 21 Exhaust system 22 Processing chamber (reaction chamber) 23 Plasma Generation chamber 24 First gas introduction system 25 Microwave power generator 26 Solenoid coil 27 Plasma 28 RF power source 41 Fin metal plate 42 DLC layer 43, 43a Fluorine-containing carbon layer having C—F bond 44 Surface of metal plate 45 Fluorine Outermost surface of contained carbon layer 48 Punched portion 49,50 Press mold 61 Stainless steel heating plate 62 DLC layer 63 Fluorine-containing carbon layer having C—F bond 64 Stainless steel heating plate surface 65 Outermost surface of fluorine-containing carbon layer 66 Heater 67 Main body 68 Stainless steel heating plate support formed on the main body 69 Temperature controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location F28F 19/04 F28F 19/04 A (72) Inventor Akira Shiokawa 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Denki Sangyo Co., Ltd.

Claims (25)

[Claims] 1. A diamond-like carbon layer formed on the surface of a base material, and the ratio (F / C value) of the number of fluorine atoms to the number of carbon atoms on the outermost surface formed on the diamond-like carbon layer (F / C value) is 0.55 or more. Which is a fluorine-containing carbon layer having a C—F bond. 2. The ratio (F / C) of the number of fluorine atoms and the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer.
The value) is 0.9 or less, and the substrate surface coating layer according to claim 1. 3. The fluorine-containing carbon layer has a ratio (F / C) of the number of fluorine atoms and the number of carbon atoms from the interface with the diamond-like carbon layer toward the outermost surface thereof.
The value) is a value obtained by sequentially increasing the value. 4. The surface of the base material has minute irregularities, and the outermost surface of the fluorine-containing carbon layer has minute irregularities corresponding to the minute irregularities of the surface of the substrate. Item 2. The substrate surface coating layer according to Item 1. 5. The base material is stainless steel, aluminum,
The base material surface coating layer according to claim 1, which is a metal substrate mainly composed of at least one selected from titanium, nickel and copper. 6. The diamond-like carbon layer has a thickness in the range of 100 to 5000 nm, and the fluorine-containing carbon layer has a thickness in the range of 5 to 200 nm.
The base material surface coating layer according to. 7. An RF bias whose voltage value is in the range of −150 V to −60 V after depositing a diamond-like carbon layer on the surface of a base material using plasma of hydrocarbon gas as a raw material. A voltage is applied, and in this state, the surface of the diamond-like carbon layer is irradiated with plasma of a fluorine-containing gas to change the upper layer portion of the diamond-like carbon layer into a fluorine-containing carbon layer having a C—F bond. A method for forming a base material surface coating layer which improves quality. 8. The plasma of the hydrocarbon-based gas and the plasma of the hydrocarbon-based gas are introduced into a reaction chamber in which the base material is arranged and the diamond-like carbon layer is formed on the surface of the base material. The method for forming a base material surface coating layer according to claim 7, which is generated by introducing plasma of an inert element gas generated in the generation chamber. 9. An RF bias having a voltage value in the range of −240 V to −60 V on the base material after depositing and forming a diamond-like carbon layer on the surface of the base material using plasma of hydrocarbon gas as a raw material. A voltage is applied, and in this state, plasma of hydrocarbon gas and plasma of fluorine-containing gas are used as raw materials, and C--F is added on the diamond-like carbon layer.
A method for forming a base material surface coating layer for depositing and forming a fluorine-containing carbon layer having a bond. 10. The method for forming a base material surface coating layer according to claim 9, wherein the diamond-like carbon layer and the fluorine-containing carbon layer are continuously formed in a reaction chamber maintained at a reduced pressure. 11. The formation of the fluorine-containing carbon layer by sequentially increasing the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber. The method for forming a substrate surface coating layer according to claim 9, which is performed. 12. The method for forming a base material surface coating layer according to claim 11, wherein only the fluorine-containing gas is contained in the reaction chamber when the formation of the fluorine-containing carbon layer is completed. 13. The method for forming a base material surface coating layer according to claim 7, wherein the base material surface has minute irregularities. 14. A heat transfer tube through which a refrigerant flows is inserted into through holes at positions corresponding to each other of a plurality of metal thin plates each having a plurality of through holes, and two adjacent heat transfer tubes of the plurality of metal thin plates are provided. In a heat exchanger fin in which a gap for air flow is formed between the metal thin plates, a diamond-like carbon layer is formed on the first and second main surfaces of the metal thin plates, and the diamond-like carbon layer is formed on the diamond-like carbon layer. Ratio of the number of fluorine atoms to the number of carbon atoms on the outermost surface (F /
A fin for a heat exchanger, characterized in that a fluorine-containing carbon layer having a C—F bond having a C value) of 0.55 or more is formed. 15. The ratio (F / C) of the number of fluorine atoms and the number of carbon atoms on the outermost surface of the fluorine-containing carbon layer.
(Value) is 0.9 or less, The fin for heat exchangers according to claim 14. 16. The ratio of the number of fluorine atoms to the number of carbon atoms (F / F) from the interface with the diamond-like carbon layer toward the outermost surface of the fluorine-containing carbon layer.
15. The heat exchanger fin according to claim 14, wherein the C value) is sequentially increased. 17. The first and second main surfaces of the metal thin plate have minute irregularities, and the outermost surface of the fluorine-containing carbon layer has first and second main surfaces of the metal thin plate. 15. The fin for a heat exchanger according to claim 14, wherein minute unevenness corresponding to the minute unevenness is formed. 18. The method for manufacturing a fin for a heat exchanger according to claim 14, wherein the thin metal plate is disposed in a reaction chamber, and the hydrocarbon is provided on first and second main surfaces of the thin metal plate. After depositing and forming a diamond-like carbon layer using plasma of a system gas as a raw material, an RF bias voltage whose voltage value is in the range of −150 V to −60 V is applied to the metal thin plate base material, and in this state, And a step of irradiating the surface of the diamond-like carbon layer with plasma of a fluorine-containing gas to modify the upper layer portion of the diamond-like carbon layer into a fluorine-containing carbon layer having a C—F bond. Method for manufacturing heat exchanger fins. 19. The method of manufacturing a heat exchanger fin according to claim 14, wherein the thin metal plate is disposed in a reaction chamber, and plasma of hydrocarbon gas is used as a raw material.
After depositing a diamond-like carbon layer on the first and second main surfaces of the thin metal plate, an RF bias voltage having a voltage value of −240 V to −60 V is applied to the thin metal plate in this state. And a step of depositing and forming a fluorine-containing carbon layer having a C—F bond on the diamond-like carbon layer by using plasma of a hydrocarbon gas and plasma of a fluorine-containing gas as raw materials. Method for manufacturing fin for heat exchanger. 20. The fluorine-containing carbon layer is formed by sequentially increasing the partial pressure ratio of the hydrocarbon-based gas and the fluorine-containing gas (the partial pressure of the fluorine-containing gas / the partial pressure of the hydrocarbon-based gas) in the reaction chamber. The method for manufacturing a fin for a heat exchanger according to claim 19, wherein 21. The method of forming a surface coating layer according to claim 20, wherein only the fluorine-containing gas is left in the reaction chamber when the formation of the fluorine-containing carbon layer is completed. 22. The metal thin plate is pressed by a mold having fine irregularities formed on its surface to transfer and form fine irregularities on the first and second main surfaces of the metal thin plate,
The method for manufacturing a fin for a heat exchanger according to claim 19 or 20, wherein the diamond-like carbon layer and the fluorine-containing carbon layer are formed. 23. The method for manufacturing a fin for a heat exchanger according to claim 22, wherein the die has a punching portion for forming a through hole in the thin metal plate during the pressing. 24. A first opening and a second opening for introducing plasma into the first and second side walls facing each other.
The thin metal plate is arranged in an intermediate portion in the reaction chamber in which the openings are formed, and the plasma of the hydrocarbon-based gas introduced from the first opening and the second opening and the fluorine-containing gas are introduced. 2. The diamond-like carbon layer and the fluorine-containing carbon layer are simultaneously formed on the first and second main surfaces of the thin metal plate by using plasma as a raw material.
21. The method for manufacturing the heat exchanger fin according to 9 or 20. 25. The base material surface coating layer according to claim 1, wherein the base material is a metal heating plate on which cooking is performed on the surface of a cooking utensil.