JP3897853B2 - Method for producing water-repellent window material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a water-repellent window material such as a window material for vehicles such as automobiles, trains, aircraft, and ships, and a window material for buildings.
[0002]
[Prior art]
Conventionally, hydrophilic glass or synthetic resin is used for this type of window material, and the base material of the window material is exposed as it is on its outer surface.
[0003]
[Problems to be solved by the invention]
A window base material such as hydrophilic glass has a disadvantage that visibility deteriorates due to water droplets adhering to the outer surface of the window base material in rainy weather or foggy weather conditions. In order to eliminate such defects, a transparent conductive film such as ITO is formed on the surface of a window base material such as glass, and tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, heptamethyltrisiloxane, or methyl group is formed thereon. Alternatively, it was considered to form a plasma polymerization film using a silicon compound having an ethyl group as a raw material. However, it is quite difficult to form a transparent conductive film on a large-area window base material, and improvement in productivity has been raised as an issue, and it has been desired to easily obtain a window material with high water repellency.
[0004]
An object of this invention is to propose the manufacturing method suitable for the water-repellent window material of a large area which can prevent adhesion of a water droplet easily.
[0005]
[Means for Solving the Problems]
In the present invention , a monomer gas of vinylidene fluoride is present as a source gas in the vacuum processing chamber, and a mesh electrode is provided directly on the surface of the window base material of a transparent or semitransparent plate glass or synthetic resin plate prepared in the vacuum processing chamber. By applying a negative DC high voltage to the mesh electrode to generate glow discharge, the contact angle that increases in proportion to the pressure increase of the monomer gas on the surface of the window base material is increased by the pressure of the monomer gas. The above object is achieved by forming a prescribed water-repellent plasma polymerized film .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As the window base material in the present invention, a generally used transparent or translucent plate glass or synthetic resin plate is used. As shown in FIG. 1, the window base material 1 is directly transparent on at least one side. Alternatively, a semi-transparent water-repellent plasma polymerized film 2 is formed to form a water-repellent window material. The plasma polymerized film 2 is obtained by decomposing and exciting a vinylidene fluoride monomer gas in plasma, A film formed by polymerization on one surface is suitable because it has sufficient water repellency. The plasma polymerized film 2 is formed to a thickness of 100 to 200 nm.
[0007]
According to experiments by the inventors, the plasma polymerized film has the property of increasing the contact angle of water droplets in contact therewith, and the insight that the contact angle is approximately proportional to the applied voltage during the formation of the plasma polymerized film. However, prior to film formation, it is necessary to form a transparent or semi-transparent conductive film on the window base material, and this conductive film formation process complicates the process and increases costs. When the film forming method and the type of film that can be manufactured easily and inexpensively were investigated, the contact angle was approximately proportional to the pressure at the time of forming the plasma polymerized film, and the contact angle could be increased by controlling the pressure of the monomer gas in the plasma polymerized film. It has been found that a water-repellent window material of 90 ° or more can be produced, and in particular, since the contact angle of vinylidene fluoride monomer gas changes in proportion to its pressure, it is advantageous for a plasma polymerized film.
[0008]
The apparatus used for carrying out the production method of the present invention is as shown in FIG. 2, and includes a vacuum exhaust port 3 connected to a vacuum pump and an inlet 10 from an evaporation source containing the raw material monomer 4 of the plasma polymerization film 2. A transparent or semi-transparent glass plate or synthetic resin plate window base material 1 is placed in the vacuum processing chamber 5 so as to face the counter electrode 7, and faces the film forming surface of the window base material 1, that is, the counter electrode 7. A mesh electrode 6 connected to a DC power source 8 was provided immediately above the surface. Then, the inside of the vacuum processing chamber 5 is evacuated to, for example, 10 ⁻² Pa, and the vapor of the raw material monomer 4 is introduced from the evaporation source into the vacuum processing chamber 5 while adjusting the monomer gas introduction valve 9, for example, 30 Pa. When a negative DC high voltage is applied to the mesh electrode 6 from the DC power supply 8, a glow discharge is generated, whereby the vapor is decomposed and excited to form a plasma polymerized film 2 on the window substrate 1. The
[0009]
The pressure at the time of forming the plasma polymerized film 2 and the contact angle of the film 2 with respect to water have a proportional relationship. For example, when an applied voltage of 1 kV is applied using a vinylidene fluoride monomer, The contact angle changes in proportion to the pressure, and a film with good water repellency having a contact angle of 119 ° under a pressure of 30 Pa is obtained. The size and shape of the window base material 1 are arbitrary. For example, even when the window base material 1 has a large area of 1 × 1 m, a plasma polymerized film 2 can be uniformly formed by providing the mesh electrode 6 along the surface of the window base material 1. Can be formed. The distance between the surface of the window base 1 and the mesh electrode 6 is about 10 mm.
[0010]
【Example】
A plate glass window substrate 1 having a thickness of 5 mm and a height and width of 0.3 × 0.3 m is installed using the apparatus having the configuration shown in FIG. 2, and the inside of the vacuum processing chamber 5 is evacuated to 10 ⁻² Pa. After that, steam was introduced from an evaporation source containing vinylidene fluoride monomer, the pressure was adjusted to 30 Pa, and a high voltage of −1 kV was applied to the mesh electrode 6. When glow discharge occurs between the mesh electrode 6 and the counter electrode 7 and the plasma polymerization film 2 of vinylidene fluoride is formed on the surface of the window base material 1 with a thickness of 100 nm, the application of voltage is stopped. The glow discharge was extinguished and the film formation was stopped there. When the obtained window material was inclined and water droplets were applied to the surface, the water droplets flowed down as they were, and no water film was formed. The contact angle of this vinylidene fluoride plasma polymerized film was 119 °.
[0011]
【The invention's effect】
As described above, according to the present invention, a transparent or translucent water-repellent plasma polymerized film is directly formed on the surface of a transparent or translucent window base material. Window material is obtained, and the plasma polymerized film is a vinylidene fluoride plasma polymerized film, which is effective in obtaining high water repellency. A net-like electrode is provided on the surface of the window base material in the vacuum processing chamber. A film having a different contact angle in proportion to the film forming pressure can be directly formed on the window substrate by applying a negative high voltage to the film to generate a glow discharge to form a water-repellent plasma polymerized film. It is possible to produce a water-repellent process at a low cost on a large-area window base material.
[Brief description of the drawings]
FIG. 1 is a cut-away side view of an example of a water-repellent window material of the present invention. FIG. 2 is a cross-sectional view of an apparatus used in the production method of the present invention. Diagram [Explanation of symbols]
1 window substrate, 2 water-repellent plasma polymerized film, 3 vacuum exhaust port, 4 monomer, 5 vacuum processing chamber, 6 mesh electrode, 7 counter electrode, 8 DC power supply, 9 monomer gas introduction valve, 10 introduction port,

Claims (1)

A monomer gas of vinylidene fluoride is present as a raw material gas in the vacuum processing chamber, and a mesh electrode is provided immediately above the surface of the window base material of a transparent or translucent plate glass or synthetic resin plate prepared in the vacuum processing chamber. By generating a glow discharge by applying a negative DC high voltage to the surface of the window substrate, the water repellency in which the contact angle that increases in proportion to the pressure increase of the monomer gas on the surface of the window base is defined by the pressure of the monomer gas A method for producing a water-repellent window material, characterized in that a plasma polymerized film is formed.

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