JP2736421B2 - Member covered with carbon film and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Application of the Invention" The present invention relates to a window, such as a front window of a transportation means such as a car, a motorcycle, a bicycle, a ship, an aircraft, etc., which can be exposed to the wind and rain. The surface of a translucent organic material is covered with carbon or a protective coating containing carbon as a main component. Further, the abrasion resistance is improved, the adhesion of dust is prevented, and the generation of static electricity is prevented.

According to the present invention, as such a thin film, carbon or a film containing carbon as a main component having sufficient hardness while having a light-transmitting property in a visible region is used as a protective film for preventing wear. In particular, this protective film can be brought into close contact with an organic material, and has an electric resistivity of 1 × 10 ^{6 to} 5 × 10 ¹² Ωcm, thereby preventing the generation of static electricity and having a smooth surface. This is to prevent the adhesion of dust to cancer.

In the present invention, a carbon film or a film containing carbon as a main component is formed on a window such as a windshield, a side glass, and a rear window by a plasma CVD method.

"Prior Art" Generally, in a plasma CVD method, a method of forming a film in a planar shape on a conductive substrate having a flat surface is considered to be industrially effective. Further, a method of forming a film with a sputtering effect while being a plasma CVD method is also known. Regarding the coating of a carbon film, which is a typical example, with respect to the patent application “Composite having a carbon film and a method for preparing the same” filed by the present inventors (Japanese Patent Application No. 56-146936, Showa)
(Filed September 17, 56). However, since these are conductor substrates, the substrate is disposed on one electrode (cathode side) of a parallel plate type using only a pair of electrodes, and a carbon film is formed on the upper surface of a flat surface using self-bias generated by itself. It is a method of filming.

"Conventional problems" However, in the conventional example in which a film is formed with such a sputtering effect, a film cannot be formed on a front window, particularly on a substrate having a curved surface such as an automobile or a motorcycle or on a window of a house. Therefore, there has been a demand for a method of forming a film on a large number of members at once in a large capacity space. The present invention has been made for such a purpose.

"Means to Solve the Problem" The present invention is applicable to a windshield, such as a car, a motorcycle, a bicycle, a ship, an aircraft, etc., which is exposed to the wind and rain, and other members having a surface of a transparent organic material such as a front window. In addition, carbon or a film containing carbon as a main component is provided as a protective film. This film has a specific resistance of 1 × 10 ^{6 to} 5 × 10 ¹² Ωcm to prevent the generation of static electricity due to friction caused by dust (generally insulating or mineral), and thus to adhere to dust and to transmit light due to dust. It prevents the devitrification or "smearing" due to the generation of micro scratches, and always preserves a vivid light-transmitting surface.

According to the present invention, as a protective film for this purpose, a film having carbon or carbon as a main component by plasma polymerization or a CVD method having a specific resistance of Vickers hardness of 600 to 6000 kg / cm ² can be adhered to an organic material. Based on the discovery of

In the present invention, a first pair of electrodes (first and second electrodes) are provided at one end and the other end of the reaction space so as to be separated from each other for such plasma polymerization, that is, for plasma CVD. Further, a second pair of electrodes (third and fourth electrodes) for applying an AC bias is provided in this space, and a substrate or member having a surface to be formed therebetween is formed using a substrate or a member holder (20). And arrange them. This holder is connected to the ground level reaction vessel via a capacitor (19). A first alternating voltage is applied between the pair of electrodes to convert the reactive gas into plasma. High-frequency voltages having phases different from each other by 180 ° or 0 ° with respect to the ground are applied to the respective electrodes from the respective high-frequency power sources, and alternating voltages having the same phase or the same phase are applied. Then, as a result, a high frequency alternating voltage is applied to the frame structure as substantially one high frequency alternating voltage to induce high frequency plasma for completely decomposing and ionizing the reactive gas. Further, the other end of each high-frequency power supply is grounded. In addition, a second pair of electrodes is provided with a base or a member interposed therebetween, and a second alternating voltage is applied thereto. Then, ions accelerated on one electrode side by the second alternating voltage sputter on the surface on which the member is to be formed, and strongly form a film on the surface on which the member is to be formed. At this time, even if the member is insulative, the unnecessary charges reach the opposite surface through the positive sheath on this surface because the member is in the plasma, and pass through the plasma atmosphere on the opposite surface to the other of the second pair of electrodes. A current can flow. Thus, even if it is an insulating substrate or member, a second pair of electrodes is provided with the electrode interposed therebetween so that the frequency is lowered so that ions can reach from the one electrode to the other electrode in a half cycle. , Reaction pressure,
By controlling the frequency, a thin film is formed on the insulative substrate or member with a sputter effect.

The first alternating voltage is a frequency at which plasma glow discharge of a reactive gas of 1 to 50 MHz is likely to occur, and the second alternating voltage is
Kinetic energy is added to a reactive gas of 10 Hz to 100 KHz to apply a sputter action on the surface to be formed. The pair of electrodes for generating the second alternating voltage is composed of independent power supplies, and the phases are changed by 180 °. The phase of the power supply was a common ground level. Further, a negative direct current self-bias is superimposed on the surface to be formed and applied by the second alternating electric field. In order to prevent this DC component from being exposed to the outside, the capacitor is cut off between the holder and the reaction vessel. Then, the plasma-activated gas is caused to accelerate and collide with the substrate by the self-bias by the first alternating voltage, and unnecessary charged-up charges on the substrate are removed by the second AC voltage. Thus, even if the surface to be formed is an organic substance having an insulating property, a film can be formed on the surface substantially in the same manner as the conductor surface.

As an example of the formation of this thin film, a hydrocarbon gas such as ethylene (C ₂ H ₄ ), methane (CH ₄ ), acetylene (C ₂ H ₂ ) or a mixed gas thereof and nitrogen fluoride or C ₂ F ₆ , C ₃ F ₈ , CF
₄ , a carbon fluoride gas such as carbon fluoride such as CH ₂ F ₂ is introduced,
By decomposing, a CC bond similar to diamond with SP ³ orbitals is created, and the specific resistance (specific resistance) 1 ×
10 ^{6 to} 5 × 10 ¹² Ωcm, typically 1 × 10 ^{8 to} 5 × 10 ¹¹ Ωcm, and an optical energy bandwidth (referred to as Eg)
Is 1.0 eV or more, preferably 1.5 to 5.5 eV in the visible region having a property similar to that of a light-transmitting diamond film or carbon as a main component (main components are hydrogen, fluorine,
Nitrogen).

The translucent organic substance using the present invention has a specific resistance of 1 × 10 ¹⁵ Ω.
It is an insulating member of cm or more, and polyester resin, alkyd resin, oil-free alkyd resin, unsaturated polyester resin, acrylic resin, and amino resin are used as the material. In particular, for an automobile line, an organic melting type organic material of acrylic lacquer, acrylic melamine, and block acrylic urethane was used.

When forming a film by the method of the present invention, a halogen element such as fluorine and nitrogen are simultaneously added to a carbide gas during plasma CVD and mixed together, and the main component is carbon having a uniform concentration gradient in a thickness direction. A multilayer composite film with or without a coating or with or without additives may be made.

 The manufacturing method of the present invention will be described below with reference to the drawings.

Example 1 FIG. 2 shows an outline of a plasma CVD apparatus for performing a method of forming a thin film on a substrate or a member such as a front window of an automobile.

In the drawing, a reaction vessel (7) of a plasma CVD apparatus is separated from the outside by a gate valve (9). Gas system (30)
In the above, argon as a carrier gas was changed from (31) to
Reactive hydrocarbon gases, such as methane and ethylene, were added from (32) to carbon fluoride (C ₂ F ₆ , C ₃ F
₈ ) From (33), oxygen as the etching gas for the reaction vessel is introduced from (34) through the valve (28) and the flow meter (29) through the nozzle (25) into the reaction system (50). . When ethylene and carbon difluoride were introduced, hydrogen and fluorine were added.
A diamond-like carbon film having a large number of SP ³ bonds (also referred to as DLC, including DLC to which an additive is added, in the present invention is referred to as carbon or a film containing carbon as a main component) can be formed.

C ₂ F ₆ and C ₃ F ₈ (3
Alternatively, NH ₃ may be introduced from (33).

A first pair of electrodes are formed above and below the reaction vessel (7) to have the same shape, and the first and second electrodes (3-1),
(3-2) is constituted by an aluminum metal mesh. The reactive gas is discharged downward from the nozzle (25). Further, a third electrode (13-
(1), (13-2),... (13-n) and other fourth electrodes (13′-1), (13′-2). (These are referred to as third and fourth electrodes). The bases or members (1-), (1-2)... (1-n) are insulating materials, to which a second alternating voltage is applied, which is substantially conductive in terms of alternating current to apply a bias. Applied. A plasma atmosphere or a positive sheath is formed on the organic substance forming surface (1 ') on the substrate or the member (1), and a negative self-bias is applied. In order to positively generate this negative self-bias, the frequency of the second alternating voltage is set to 10 Hz to 100 KHz and a low frequency such that ions spread between the third and fourth electrodes for a half cycle (half cycle). And The substrate or the member (1) has a surface (1 ') on which an organic substance is formed, and the reactive gas converted into plasma of the glow discharge by the first high frequency alternating voltage is uniformly dispersed in the reaction space (8). The plasma potential in the reaction space was made homogeneous.

Further, in order to make the potential distribution in the plasma reaction space more uniform, alternating voltages of two independent frequencies can be applied to the power supply system (40). The first alternating voltage is a high frequency of 1 to 100 MHz, for example, 13.56 MHz, and is provided by a pair of two power supplies (15-1) and (15-2), that is, (15).
Matching boxes (16-1), (16
-2). The phases of the matching boxes are adjusted by a phase adjuster (26) so that they can be supplied 180 ° or 0 ° from each other. It has a symmetric or in-phase output, and power supplies (15-1) and (15-2)
Are connected to a pair of first ends (4-1) and (4-2), respectively.
And the second electrodes (3-1) and (3-2). In addition, each power supply (15-1), (15
The other end of -2) is grounded (5-1) and (5-2). A second 10 Hz to 100 KHz, for example, 50 Hz alternating voltage is supplied from a power supply (17), that is, (17-1), (17-2), and a pair of third electrodes (13-1),. The fourth electrode (1
3'-1)... (13'-n) and are applied. The output at the pair of electrodes (13) and (13 ') is configured to apply a self-bias to the base or member (1) sandwiched between the pair of electrodes.

Thus, plasma (8) is generated in the reaction space. The exhaust system (25) exhausts unnecessary gas through a pressure adjusting valve (21), a turbo molecular pump (22), and a rotary pump (23).

These reactive gases are present in the reaction space (60) at 0.001 to 1.0
torr For example, 0.05 torr.

In such a space, 0.5 to 5 KW of 13.56 MHz frequency
(Per unit area 0.03~3W / cm ²⁾ for example adding the first high frequency voltage of 1 KW (high energy per unit area 0.6W / cm ^2). Further, by applying an AC bias by the second alternating voltage, a negative self-bias voltage of -200 to -600 V (for example, the output is 1 KW) is applied on the surface to be formed,
The reactive gas accelerated by the negative self-bias voltage was formed on the substrate or member while being sputtered, and a dense film could be formed.

The reactive gas was, for example, a mixed gas of ethylene and carbon fluoride. The ratio is C ₂ F ₆ / C ₂ H ₄ = 1/4 to 4/1, typically 1/1. By changing this ratio, the transmittance and the specific resistance can be controlled. The temperature of the substrate or member (1) is maintained at 〜150 ° C., typically at room temperature without external heating. Thus, a specific resistance is 1 × 10 ^{6 to} 5 × 10 ¹² Ωcm on the surface to be formed, and a film is formed in close contact with an organic resin. With respect to visible light, carbon or a film containing carbon as a main component to which fluorine and hydrogen having an amorphous structure or a crystal structure that are transparent to light are added is 0.1 to 8 μm, for example, 0.5 μm (flat portion), and 1 to 3 μm (convex). Part). The deposition rate was 100-1000 ° / min.

In this way, it was possible to form a carbon-based coating on the front window and other members, particularly carbon containing not more than 30 atomic% of hydrogen in carbon and containing 0.3 to 10 atomic% of fluorine. . 100-200 on organic matter
The first carbon made of only ethylene was provided to a thickness of 0 °, and a multi-layer film mainly composed of carbon to which fluorine and hydrogen were added was formed thereon.

Example 2 In this example, as shown in FIG. 1, a film containing carbon as a main component was formed on a main part of a translucent organic material using the apparatus used in Example 1.

FIG. 1 (A) is a longitudinal sectional view of a front window (1) of an automobile. Fig. 1 (B) shows the cross section.
Shown in

In FIGS. 1A and 1B, the light-transmitting plastics (1) is lightweight, and is made of, for example, an acrylic resin. On the substrate or member (1) having the surface to be formed, carbon or a wear-resistant protective film (45) containing carbon as a main component was provided in a thickness of 0.1 to 8 μm.

In the present invention, in particular, the coating mainly composed of carbon or carbon to which fluorine is added has a specific resistance of 1 × 10 ^{6 to} 5 × 10 ¹² Ωcm in order to prevent adhesion of dust due to generation of static electricity.
And particularly preferably in the range of 1 × 10 ⁷ to 1 × 10 ¹¹ Ωcm.

FIG. 1 (C) shows the structure formed only on the surface of the window. The vertical sectional views of FIGS. 1A and 1C may be side windows and mirror surfaces. Large 1 figure (D)
Is for a sphere and (E) is for a cylinder. The present invention is excellent in that these materials are strongly used in practical use, and dust of mineral substances easily collide with them, and as a result, devitrification and turbidity are easily generated by abrasion.

"Effect" The present invention inorganic glass, is also effective against any translucent material organics, especially carbon based Vickers hardness 600~3000Kg / cm ² to well-drained fluorine is added the upper surface Coating or Vickers hardness of 1000-7000
A multilayer film of carbon (to which hydrogen was also added) of Kg / cm ² was coated on an organic material by being in close contact with the organic material. As a result, it was possible to form a thick and wear-resistant film due to the protruding portions that were exposed to the wind and rain and that had a lot of dust with dust.

Until now, the front windows of automobiles and the like were extremely easy to get dust in fine weather. However, according to the present invention, it was possible to reduce the generation of static electricity caused by the impact of insulating dust on the surface and the accompanying dust adhesion.

As shown above, it is possible to control the light energy of the DLC by controlling the optical energy bandwidth of the DLC. Being able to adhere to organic matter that does not exist is effective in realizing the possibility of making a plastic window that could not be used at all because of its softness.

As is clear from the above description, the present invention is particularly effective for those provided with an organic resin or a coating of a multilayer thereof. This composite, as seen in many other embodiments, is of immeasurable application, especially when the carbon can be formed at low temperatures below 150 ° C., and therefore, due to the transformation of organic matter on the underlying painted surface. The feature is that the color tone does not change, and its hardness and adhesion to a substrate or a member are extremely excellent.

[Brief description of the drawings]

FIG. 1 shows an example in which a carbon film or a protective film containing carbon as a main component is coated on a member such as a front window of the present invention, and an essential part thereof. FIG. 2 shows an outline of a plasma CVD apparatus manufacturing apparatus according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mari Sasaki 398 Hase, Atsugi-shi, Kanagawa Semiconductor Energy Research Institute, Inc. ) Inventor Atsushi Kawano 398 Hase, Atsugi-shi, Kanagawa Prefecture Examiner at Semiconductor Energy Laboratory Co., Ltd. Sumiko Yoshimizu (56) References JP-A-2-80300 (JP, A)

Claims (4)

(57) [Claims] 1. A light-transmitting member having an insulating property, wherein a carbon film having a specific resistance of 1 × 10 ^{6 to} 5 × 10 ¹² Ωcm or a film containing carbon as a main component is provided on the surface of the member. A member covered with a carbon film. 2. The light-transmitting member according to claim 1, wherein the light-transmitting member comprises a front window, a rear window, a side mirror, and a side window of a car, a motorcycle, a bicycle, a ship, or an aircraft which can be exposed to the weather. A member covered with a carbon film. 3. The member covered with a carbon film according to claim 1, wherein the light-transmitting member is made of an organic material, and a light-transmitting carbon film is provided on the organic material. 4. A first pair of electrodes for generating high-frequency plasma in a reaction vessel, an insulating member provided in the reaction vessel, and held under reduced pressure to sandwich the member. And a second pair of electrodes, an AC bias is applied between the electrodes, and a carbide gas is introduced into the atmosphere under the reduced pressure to apply a high-frequency voltage to the first pair of electrodes. Forming a film containing carbon or carbon as a main component on the member by converting the gas into a plasma to produce a member covered with a carbon film.