KR100843839B1 - Method for combustion chemical vapor deposition to enhance corrosion resisitance of silicon oxide flim - Google Patents

Abstract

A CCVD(Combustion Chemical Vapor Deposition) method that can enhance corrosion resistance of the metal surface by densely forming a silicon oxide film on a metal surface by using CCVD techniques is provided. In a combustion chemical vapor deposition method for transferring a vapor phase of a precursor to a burner by a carrier gas and depositing the vapor phase of the precursor onto a substrate by a flame of combustion heat, a combustion chemical vapor deposition method of a silicon oxide film with excellent corrosion resistance comprises: controlling the injection ratio of an oxidation gas to a combustion gas to a range of 10:190 to 10:210 to secure the combustion heat in the burner; using HMDSO(hexamethyldisiloxane), and controlling the injection amount ratio of the carrier gas containing the vapor phase of the precursor to the oxidation gas to a range of 210:0.8 to 210:2.4; and adjusting the distance from the burner to the substrate to less than 10 mm, thereby depositing the vapor phase of the precursor onto the substrate in a blue bright zone of the flame, wherein the silicon oxide film has a deposition coating thickness of 4 to 35 nm.

Description

Method for Combustion Chemical Vapor Deposition to enhance corrosion resisitance of silicon oxide flim

1 is a schematic diagram of a combustion chemical vapor deposition apparatus to which the present invention is applied.

European Patent Publication 737729

United States Patent Publication 5449414

United States Patent Publication 4364731

United States Patent Publication 5652021

United States Patent Publication 4600390

The present invention relates to a method for depositing an organosilane into a silicon oxide film by combustion chemical vapor deposition. More specifically, the present invention relates to a method of improving the corrosion resistance of a silicon oxide film using a precursor of hexamethyldisiloxane (HMDSO).

The surface of general metal products is chemically treated for the purpose of improving corrosion resistance and durability, and the coating film formed by these chemical treatments has organic barrier coatings, as well as organic and inorganic coatings formed on top of the chemically treated film. It must have the property of protecting the surface of metal products from corrosion by physical and chemical bonding with.

Conventionally, phosphate or chromate treatments have been carried out for the corrosion resistance of the metal surface and the bonding with the top coating. Chromate treatment Black silver metal phosphate treatment is a surface treatment using a chemical treatment solution containing chromium or metal phosphate to form a passivation film of chromium oxide or phosphate on the surface of the adherend to provide corrosion resistance and other surface characteristics. It is used a lot for. In particular, in the case of chromate treatment, it is very excellent in corrosion resistance and adhesive modification properties for the top coating, and the treatment cost is very economically used as the most widely used metal surface treatment method.

However, the surface treatment of the metal by chromate contains chromium hexavalent, which is very harmful to the human body in the chemical solution itself after treatment, and the treatment waste liquid is generated, and this waste liquid is recognized as a substance causing serious environmental pollution. In June, 2007, there will be a full-scale regulatory movement on chromium use in developed countries, as well as chromium materials from July 2006 under the Restriction of Hazardous Substances (RoHS) Act on electricity and electronics. Full regulations on disposal will be implemented. Accordingly, there is a trend to find or develop an alternative treatment for providing corrosion resistance (corrosion resistance).

In addition to chromate treatment, alternative treatments using phosphate or other metal oxides are under development, but both use liquid treatment solutions, which still have the potential for secondary environmental pollution by wastewater and do not yet exhibit the same level of corrosion resistance as chromate treatment. It is not available and economically expensive compared to chromate treatment. Therefore, there is a trend to find or develop a treatment that can replace the chromate and metal phosphate chemical treatment. Representative examples are European Patent 737729 and US Patent 5449414.

European Patent 737729 discloses a water-soluble polyacrylic acid and a divalent metal hydroxide (Ca (OH) ₂ , Ba (OH) ₂ , etc.) for crosslinking thereof, an amine compound and mono acid, fluoride, etc. for improving adhesion to metals. A technique for forming a chemically treated film on the surface of a plated steel sheet by a composition has been proposed. The surface treatment film by this technique forms a very weak water-resistant and fragile coating film, which makes it very difficult to use it as a surface chemical treatment method for improving the corrosion resistance.

U.S. Patent 5449414 claims that the Group 4A transition metal fluoride compound anion and other transition metal cations can be chemically treated on the surface of the metal to ensure excellent corrosion resistance and lacquer adhesion. This treatment is a method of increasing the surface energy by etching the metal surface, and due to insufficient adhesion between the chemical treatment liquid and the metal surface, it is difficult to form a film, which makes it difficult to use as a chemical treatment agent for improving corrosion resistance. .

On the other hand, there is known a technique using a dry coating method, unlike the wet coating method described above.

Unlike the wet method, the dry method is a method in which a solid substance is vaporized to adsorb onto a surface of a subject, or a gaseous reactant is formed of energy using heat or plasma to form a coating film. Therefore, compared with the coating technology by the reaction of the liquid phase, it is possible to control the crystal structure, direction, thickness, etc. of the coating film, and there is an advantage of obtaining a highly functional film.

The dry method can be roughly classified into physical vapor deposition (PVD) technology and chemical vapor deposition (CVD) technology.

PVD has not yet been developed with a very advanced form of breakthrough surface treatment or technology for processing large areas at high speed. Therefore, it is difficult to apply the high-speed processing as a general product and is used only in the high value-added semiconductor industry.

CVD is a technique of forming a thin film by supplying a raw material gas containing a member of a target thin film to a space in which a substrate is placed, by chemical reaction or decomposition of raw material gas molecules on the gas phase and the surface of the substrate. In CVD, a combustion chemical vapor deposition method (hereinafter simply referred to as CCVD) is a technique for vaporizing, decomposing, and oxidizing a vapor deposition using a heat of combustion deposited under atmospheric pressure as an energy source.

U.S. Patent 4364731 proposes an oxide film such as silica or alumina on a substrate by sputtering or the like in a PVD technique, and then improves adhesion to an organic resin by processing an organic silane next. In this case, oxide film is formed using PVD method that requires vacuum, which makes the process complicated and difficult to control, requires additional equipment and process development for mass production, and economically expensive equipment and process cost. Difficult to produce

US Patent 5652021 proposes a CCVD treatment method and apparatus for forming an oxide film by melting a precursor in an organic solvent and burning it with oxygen or air. According to this method, various types of oxide films can be formed, and coating of various materials other than the oxide film is also possible. However, the technique focuses on the characteristics of the oxide film and other coatings themselves formed by CCVD, and therefore does not provide a solution to the problem of additional corrosion resistance improvement.

U.S. Patent 4600390 proposes CCVD equipment and treatment conditions for a method of improving adhesion of dental plastics by performing silicon oxide coating and organosilane treatment by CCVD using organosilane as a precursor to a metal prosthesis. However, the present invention merely proposes a technique limited to plastic adhesion of a prosthesis by simply forming a film by CCVD treatment, but a technique or process related to corrosion resistance has not been proposed yet.

An object of the present invention is to provide a CCVD treatment method capable of increasing the corrosion resistance of a metal surface by densely forming a silicon oxide film using CCVD technology.

In the combustion chemical vapor deposition method of the present invention for achieving the above object, in the combustion chemical vapor deposition method of transferring the vapor phase of the precursor to the burner by the carrier gas and depositing on the substrate by the flame of combustion heat,

The heat of combustion in the burner is secured by the input ratio of the oxidizing gas to the combustion gas as 10: 190-10: 210,

The precursor is HMDSO (Hexamethyldisiloxane), and the input amount of the carrier gas including the vapor phase of the precursor to the oxidizing gas is 210: 0.8-210: 2.4

And depositing on the substrate in the blue blight area of the flame.

According to one embodiment of the present invention, the deposition process of the silicon oxide film is preferably performed 2-15 times. In addition, the oxidizing gas is most preferably air. The thickness of the deposited coating film is most preferably 45nm or less. According to an embodiment of the present invention, the distance of the substrate to the burner is 10 mm or less, more preferably 7 mm or less. In addition, the substrate may be applied to a metal, non-metal, plastic, and the like, and has a significant meaning in that it can be applied to a large plate such as a steel plate.

Hereinafter, the present invention will be described in detail.

A schematic of the apparatus applied to the combustion chemical vapor deposition method is shown in FIG. 1. 1 is an example provided to more fully explain the present invention to those skilled in the art, and the present invention is not limited thereto. Shapes and sizes in the drawings are exaggerated for clarity. In FIG. 1, air is used as an oxidizing gas and also as a carrier gas of a precursor.

The CCVD apparatus is mainly composed of a raw material supply part, a control part, a burner, and a substrate transfer part.

The control unit functions to evaporate the precursor which is a raw material of the deposition material and to supply the precursor vapor to the saturated state in the air (carrier gas supply). In addition, the function of controlling the supply amount of the oxidizing gas and the combustion gas for the generation of the combustion energy that is the source of the chemical reaction energy of the precursor.

The burner functions to generate and deposit a deposition material by chemical reaction of an incoming precursor while burning oxidizing gas and combustion gas supplied from a control unit.

The substrate transfer unit transports the deposited material into a flame at which the chemical reaction of the burner occurs at a constant speed so as to be deposited. Herein, the substrate is not particularly limited in materials such as metal, nonmetal, plastic, and a large plate like a steel sheet may be applied.

 The characteristics of the silicon oxide film produced in this CCVD process are determined by various operating conditions. In the present invention, it is characterized by deriving the optimum operating conditions through the examination of various factors affecting the corrosion resistance when forming the silicon oxide film using HMDSO as a precursor. In the present invention, a dense film of silicon oxide containing a large amount of hydroxyl is formed on a surface of a substrate, particularly a metal, by using CCVD, and the barrier property of the deposited film formed on the surface of the adherend, Combustion chemical vapor deposition (CCVD surface treatment) in which the corrosion resistance of metal surfaces is increased by chemical low bonding with a protective film or a coating for imparting functionality.

According to the present invention, a silicon oxide film containing a large amount of hydroxyl (hydroxyl) is formed using HMDSO as a precursor. This coating is required to increase the corrosion resistance on the surface of the adherend. The present invention is controlled by the input amount of the carrier gas, including the vapor phase of the precursor to the oxidizing gas during the CCVD process, the distance from the burner to the substrate.

The heat of combustion in the burner is determined by the input ratio of the oxidizing gas to the combustion gas. According to an embodiment of the present invention, the heat of combustion may be secured by setting the ratio of the combustion gas: oxidizing gas to 10: 190-10: 210. If the amount of oxidizing gas supplied is small, sufficient flame cannot be obtained for the treatment, and if too large, the temperature of the flame is too high, which may damage the surface of the subject. If the amount of supply of the combustion gas (LPG) is small, it is difficult to generate a flame, and if too large, it is difficult to bring about poor treatment or to maintain the flame by incomplete combustion.

In CCVD, the vapor phase of the precursor is transferred to the burner by the carrier gas. At this time, the supply amount of the carrier gas including the vapor phase of the precursor is adjusted by the supply ratio with the oxidizing gas. That is, the supply ratio of the carrier gas containing HMDSO (Hexamethyldisiloxane) to the oxidizing gas is 210: 0.8-210: 2.1. When the supply amount of the carrier gas containing HMDSO is small, it is difficult to obtain a film thickness having characteristics. In addition, when the supply amount of the carrier gas containing HMDSO is excessive, the deposition particles are enormous, which makes it difficult to form an efficient and dense film and at the same time, the amount of HMDSO consumed that does not form a deposition layer on the surface of the object is not economically good. .

Flame in CCVD can be divided into two zones according to the color. It is divided into a blue bright region and a dark flame region which are high temperature plasma states. According to the present invention, from the aspect of securing corrosion resistance, it is most preferable to deposit in the blue bright frame region. According to one embodiment of the present invention, the distance from the burner to the substrate is 10 mm or less, more preferably 7 mm or less, for the deposition process. By adjusting the distance from the burner to the substrate, a film having excellent corrosion resistance is obtained.

In the present invention, the carrier gas and the oxidizing gas are most preferably air. In addition, the combustion gas may be applied to LPG, LNG and the like.

In the present invention, the number of deposition processes of the silicon oxide film is more preferably within 15 times, preferably 2 to 15 times. Even if the number of treatments exceeds 15, the increase in corrosion resistance is not so great.

The operating conditions of the present invention described above are derived from the respective operating conditions while changing the supply flow rate of the oxidizing gas in the 300mm burner to a condition of 180-255 l / min. Of course, if the burner conditions are different, these conditions will change. Therefore, in the present invention, even if the size of the burner changes by relatively operating conditions derived from the 300mm burner, the conditions of the present invention are applicable.

In the present invention, in particular, a metal plate (steel plate) may be preferably applied.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

By varying the distance between the burner of the CCVD apparatus and the zinc electroplated steel sheet on the surface of the galvanized steel sheet, the CCVD process is performed to form a silicon oxide film and the bar or roll of one-component organic anti-fingerprint resin on the treated surface. After the coating (roll coating) and curing, the effect of corrosion resistance of CCVD treatment with distance was examined through salt spray test (SST).

HMDSO is used as the precursor (precursor) based on a 300mm long CCVD burner, and the air supply is 210 l / min in the CCVD parameters, thus the combustion gas (LPG) is 10 L / min, and the precursor vapor is 0.8 L / min. min, that is, supply ratio of air, combustion gas and precursor vapor is 21: 1: 0.8, and the processing speed of specimen is fixed at 60m / min, and the thickness of silicon oxide is 6 ~ 14nm by 4 ~ 6 treatments. When processing, the CCVD treatment distance is divided into the thermal plasma region, the thermal plasma region, the bright flame region, the dark flame region, and the flame end, depending on the color of the flame. The effect of corrosion resistance on the distance from the specimen to the specimen (treatment distance) was investigated.

Processing count 0 times 4 times 6th Processing distance (mm) - 7 40 Tip 7 40 Tip Thickness (nm) - 7.9 7 7 11.7 11 10 Corrosion Resistance (SST) 72hrs WR 20% No rust No rust WR ~ 3% No rust No rust WR ~ 3% 144hrs RR 70% WR 5% WR 5-7% WR 7% WR 5% WR 5-7% WR ~ 7% RR: Red Rust, WR: White Rust

As shown in Table 1, the specimen which was not subjected to CCVD was white blue from SST 72 hours, and more than 70% of the surface was red blue at 144 hours. However, in the case of CCVD treated specimens, there was no rust until 72 hours, and white rust occurred after 144 hours. The effect of treatment distance is decreased in order of the bright plasma region, the dark flame region, and the end of the flame, which are the thermal plasma regions. The particles are deposited directly on the surface to form a dense coating film. As the distance increases, relatively large particles are deposited by agglomeration of fine particles on the way to the surface of the subject after the formation of the chemical reactant. It lowers and corrosion resistance falls.

Example 2

CCVD treatment was carried out on the surface of the galvanized steel sheet by varying the supply amount of CCVD precursor vapor and the number of treatments (deposition film thickness) to form a silicon oxide film, and the organic resin was coated on the treated surface to evaluate corrosion resistance (SST, Salt Spray Test) examined the corrosion resistance of CCVD.

HMDSO is used as a precursor based on a 300mm long CCVD burner, and the air supply is 210 l / min in the CCVD parameters, and thus the combustion gas (LPG) is 10 L / min. After the sample was fixed at 60m / min and the processing distance was set at 7mm (thermal plasma region), the silicon oxide film-deposited coating film was formed on the galvanized steel sheet by CCVD while changing the number of treatments and the amount of precursor vapor. It was. After coating or curing one-component organic anti-fingerprint resin on the surface and curing it, the corrosion resistance evaluation (SST, Salt Spray Test) was used to determine the effect of corrosion on the CCVD treatment according to the amount of precursor vapor supply and the number of treatments (deposition film thickness). I looked at it.

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Cycles (Cylces) Coating thickness (nm) Precursor flow (L / min) Corrosion Resistance (SST) 72 hours 144 hours 0 - - WR 20% RR 75% One 1.7 0.4 WR 7% RR 70% 2 0.8 WR 5% RR 70% 2.2 1.6 No rust WR 20% 2.5 2.1 No rust RR 5% 2.7 3.0 No rust WR 15% 2 3.4 0.4 No rust RR 15% 4 0.8 No rust RR 5% 4.3 1.6 No rust WR 10% 4.9 2.1 No rust WR <5% 5.1 3.0 WR 5% WR <5% 4 6.5 0.4 No rust WR 15% 7.9 0.8 No rust WR 5% 9.7 1.6 No rust WR 5% 8.4 2.1 No rust WR 10% 9.9 3.0 No rust WR 15% 6 10.2 0.4 No rust WR 7% 11.7 0.8 No rust WR 5% 12.4 1.6 No rust WR <5% 14.1 2.1 No rust WR 5% 15.0 3.0 WR 5% WR 10% 10 16.4 0.4 No rust WR 5% 19.9 0.8 No rust WR 5% 21.1 1.6 No rust WR <5% 23.3 2.1 No rust No rust 24.9 3.0 No rust WR 10% 15 24.6 0.4 No rust WR <5% 29.9 0.8 No rust WR <5% 31.7 1.6 No rust WR <5% 34.9 2.1 No rust WR <5% 37.3 3.0 No rust WR 10% 20 32.8 0.4 No rust WR <5% 39.8 0.8 No rust WR 10% 42.2 1.6 No rust WR 10% 46.6 2.1 No rust WR 20% 49.8 3.0 WR 5% RR 10%

As the number of CCVD treatments increases, that is, the dense silicon oxide coating film by CCVD treatment becomes thicker and the corrosion resistance is improved by the barrier effect. Corrosion resistance is increased by forming silicon oxide coating film of 4nm ~ 35nm thickness, but the improvement of corrosion resistance is slowed down more than 15 times (45nm). Corrosion resistance is reduced due to the weakening of compactness caused by the formation of macroparticles. When the flow rate of the precursor vapor was 0.4L / min or less, the film formation was too slow, requiring much processing time to obtain a film of sufficient thickness for corrosion resistance. Corrosion resistance is improved due to the rapid formation of the deposited film, but the density of the deposited film is weakened by the enlarging of particles at 2.1L / min or more. It was hard to do.

As described in the above embodiments, HMDSO is used as the precursor, the number of treatments is 2 to 15 times, the processing distance between the specimen and the burner is ~ 10 mm, which is the thermal plasma region of the flame, and the input ratio of the precursor to the air supply is 0.8: 210 to 2.1. The surface treatment method of metal using CCVD of: 210 L / min is excellent in improving the corrosion resistance, and thus it is very useful for industrial applications such as metal surface treatment.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims, and various forms of substitution, modification, and within the scope not departing from the technical spirit of the present invention described in the claims. It will be apparent to those skilled in the art that changes are possible.

As described above, the present invention is excellent in the effect of improving the corrosion resistance, in particular, it can be seen that very useful in the application of industrial fields, such as coating of the metal surface.

Claims (6)

In the combustion chemical vapor deposition method in which the vapor phase of the precursor is transferred to a burner by a carrier gas and deposited on a substrate by a flame of combustion heat, The heat of combustion in the burner is secured by the input ratio of the oxidizing gas to the combustion gas as 10: 190-10: 210, The precursor is HMDSO (Hexamethyldisiloxane), and the input amount of the carrier gas including the vapor phase of the precursor to the oxidizing gas is 210: 0.8-210: 2.4, Forming a silicon oxide film including depositing on the substrate in the blue blight area of the flame with a distance from the burner to the substrate within 10 mm, The deposition coating thickness of the silicon oxide film is a combustion chemical vapor deposition method of the silicon oxide film excellent corrosion resistance, characterized in that 4 to 35nm. delete The method of claim 1, wherein the deposition process of the silicon oxide film is performed 2-15 times. The method of claim 1, wherein the oxidizing gas is air. The combustion chemical vapor deposition method of claim 1, wherein the substrate is a metal plate. delete

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