KR100742857B1 - Method for Combustion Chemical Vapor Deposition to enhance wetting of silicon oxide flim - Google Patents

Abstract

Provided is a combustion chemical vapor deposition (CCVD) method for depositing a silicon oxide film having improved wettability using a precursor of hexamethyldisiloxane (HMDSO).

The combustion chemical vapor deposition method is a combustion chemical vapor deposition method in which a vapor phase of a 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: 0.81-210: 2.4

And depositing on the substrate in the blue light region of the flame.

Combustion Chemical Vapor Deposition, Silicon Oxide, HMDSO, Wetability

Description

Method for Combustion Chemical Vapor Deposition to enhance wetting 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 wettability of a silicon oxide film using a precursor of hexamethyldisiloxane (HMDSO).

The surface of various materials such as metals and plastics is coated with organic or inorganic materials for the purpose of surface protection, functionality, durability and aesthetics, and coloring. In order for this coating to be well done, the coating solution should be excellent in affinity with the surface of the object, so that the surface of the object is well buried, that is, wetting should be excellent. Coating solutions with poor wettability cannot be surface coated, no matter how good they are.

In this method for wettability modification, a compound that reduces the surface tension of the coating solution, that is, a wetting agent, is added to the coating solution composition to improve the wettability of the solution. Alternatively, in the case of metal surfaces, a method of increasing wettability by increasing surface energy through chromate or phosphate treatment is used. The use of wettability modifiers in coating solutions should be used to the extent that they do not affect the properties of the entire coating. The coating may still be difficult because the wettability improvement is not great, and even if the coating is possible when the limit is exceeded, it may be difficult to impart the properties by the desired coating.

Surface treatment of chromium or metal phosphates is widely used to impart wettability and other surface properties. However, such a surface treatment method generates a treatment waste liquid, which is recognized as a substance causing serious environmental pollution. 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 is relatively thick to be applied as a wettability improvement film having a thickness of 1 μm or more, and it is very difficult to be used as an actual wettability improvement surface chemical treatment method by forming a very weak water-resistant and fragile coating film.

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 method is a method of increasing the surface energy by etching the metal surface is not enough wettability between the chemical treatment liquid itself and the metal surface (by the film formation is difficult) difficult to use as a chemical treatment agent for improving the wettability.

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. In the dry method, 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, and chemical reactions on the surface of the substrate. In CVD, a combustion chemical vapor deposition method (hereinafter, simply referred to as CCVD) is a technique of 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 by PVD method which requires vacuum, which makes the process complicated and expensive, and increases the cost and silane by treating organic silane reactive with applied organic resin on oxide film again for adhesion with organic resin. There is difficulty in selection.

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, this technique focuses on the characteristics of the oxide film and other coatings themselves formed by CCVD, and thus does not provide a solution to the additional solution coating, wettability and adhesion 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 is limited to the purpose of bonding plastic moldings using silicon oxide and organosilane treatment, and it is difficult to use them universally to improve wettability.

The present invention forms a film of silicon oxide using the CCVD technology, thereby increasing the reactivity and surface energy of the solid surface to form a functional coating film using a different coating solution, so that the solution is buried on the solid surface to facilitate the coating To provide a treatment method, the purpose is.

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: 0.81-210: 2.4

And depositing on the substrate in the blue light region of the flame.

In this invention, it is preferable to form a silicon oxide film 2-3 times. In the present invention, the carrier gas and the oxidizing gas are most preferably air. In addition, the substrate may be applied to metals, non-metals, plastics, and the like, and may also be applied to a large plate like a steel sheet.

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 provided as an example in order to more fully explain the present invention to those skilled in the art, 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 cone portion 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 material 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 wettability when forming the silicon oxide film using HMDSO as a precursor.

The heat of combustion in the burner is determined by the input ratio of the oxidizing gas to the combustion gas. In the present invention, the heat of combustion is 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 feed amount of the combustion gas (LPG) is small, it is difficult to generate a flame, and if too large, it is difficult to bring a 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 oxidizing gas to the carrier gas containing HMDSO (Hexamethyldisiloxane) is set to 210: 0.81-210: 2.4. 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, in terms of ensuring wettability, it is preferable to perform a deposition treatment in a blue blight area. The blue blight area is about 7mm from the burner tip. Of course, in the case of four or more deposition processes, the wettability may be secured even in the dark frame region.

As such, when the deposition process is performed in the dark frame region, the distance is too far, and the amount of raw materials consumed increases, and the deposition coating film may be formed non-uniformly.

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 preferably 2-3 times. It is enough to secure wettability even if it is processed within 3 times.

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 100mm burner to a condition of 60-85 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 100mm 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

The temperature of the steel sheet was measured according to the supply condition (heating heat) of air and LPG as shown in Table 1 on the 100 mm long burner for the zinc electroplated steel sheet. The results are shown in Table 1.

Air (l / min) 60 65 70 70 70 70 70 75 80 85 LPG (l / min) 2.9 3.1 3.2 3.3 3.5 3.7 3.9 3.6 3.8 4.0 Flame Formation Ability O O X O O O X O O O Combustion Gas to Air Supply Ratio 10: 210 10: 210 10: 220 10: 210 10: 200 10: 190 10: 180 10: 210 10: 210 10: 210

As shown in Table 1, it can be seen that the effect of the flame formation depends on the ratio of the combustion gas (LPG) and oxidizing gas (air). In terms of flame formation, the supply ratio of the combustion gas (LPG) and the oxidizing gas (air) was 10: 190-10: 210. In Table 1, "O" is a pass and "X" is a fail.

Example 2

Based on the 100mm burner, the supply of oxidizing gas (air) is 70 l / min, the combustion gas (LPG) is 3.3 l / min (the ratio of air and combustion gas is 210: 10), and Tables 2 and 3 As described above, the silicon oxide film was formed by CCVD while varying the supply conditions of the carrier gas (air) and the oxidizing gas including the HMDSO precursor and the distance from the burner to the surface of the galvanized steel sheet. The blue bright area is an area up to about 7 mm from the burner. After that, the contact angle with the surface of the galvanized steel sheet was measured using pure water to test the improvement of wettability and change over time.

The wettability was determined by measuring the contact angle between the surface of CCVD and water droplets using pure water. In the case of coating with a common solution, the lower the contact angle is, the better the condition is that the contact angle up to 24 hours is 30 degrees or less.

division Oxidation Gas Supply (l / min) Supply amount of carrier gas containing precursor (l / min) Supply ratio of oxidizing gas to carrier gas containing precursor A1 70 0.27 210: 0.81 A2 70 0.54 210: 1.62 A3 70 0.8 210: 2.4

As shown in Table 3, it was confirmed that the surface contact angle of the steel sheet not treated with the silicon oxide film showed a 62.5 ° angle, but the contact angle was lowered and the surface energy was increased when the CCVD treatment was performed. In general, good results were obtained under the conditions of 210: 0.81-210: 2.4 in the amount of the oxidizing gas supplied to the amount of the carrier gas containing the precursor (hereinafter simply referred to as carrier gas (precursor)). In the case of two treatments, the change in contact angle with 210: 0.81 was slightly increased. In the case of four treatments, the change of the contact angle with the dark frame was small.

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 wettability, and in particular, it can be seen that it is very useful for application in industrial fields such as coating of metal surfaces.

Claims (5)

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: 0.81-210: 2.4 Combustion chemical vapor deposition method of the silicon oxide film having excellent wettability comprising the deposition on the substrate in the blue blight area of the flame. The method of claim 1, wherein the deposition of the substrate is performed by setting the distance from the burner to the substrate within 7 mm. The method of claim 1, wherein the deposition process of the silicon oxide film is performed 2-3 times. The combustion chemical vapor deposition method of claim 1, wherein the carrier gas and the oxidizing gas are air. The combustion chemical vapor deposition method of claim 1, wherein the substrate is a metal plate.

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