JPH0557227A - Manufacture of organic thin film - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of an organic thin film being not limited in size by taking up a monomolecular film formed on a water surface on a water film formed on a roller having a hydrophilic surface and transferring it to a substrate continuously. CONSTITUTION:An amphiphilic molecule is developed on the water surface of a water tank 13 and the monomolecular film is formed, and then a taking-up roller 14 is rotated and the monomolecular film is taken up on the water film formed on the roller, and a compression plate 12 is moved as it is taken up and a necessary pressure is kept. A film to be a substrate is brought into contact with the monomolecular film with a transfer roller 15 and it is transferred until the compression plate 12 proceeds near to the taking -up roller 14 and a new monomolecular film is formed with the compression plate 11. The compression plate 12 is submerged while the pressure is kept and it is moved along an orbit 17, and the monomolecular film formation is continued and successively transferred. By repeating above operation, a continuous LB membrane is obtained and the conventional defect that the size of the LB membrane is limited by the size of the substrate, is overcome.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a novel organic thin film. More specifically, it relates to a method for producing a novel continuous organic thin film.

[0002]

2. Description of the Related Art A Langmuir-Blodgett film (hereinafter abbreviated as LB film) is used as an organic thin film whose orientation and alignment are controlled on the order of molecules. What is LB film?
An organic thin film prepared by a method, that is, a method in which an amphipathic molecule is spread on the surface of water and compressed and oriented by applying a constant static pressure to the monomolecular film, which is formed one by one and transferred to a substrate. .. The process of the vertical dipping method, which is a general LB film manufacturing method, is sequentially shown in FIGS. 1 (a) to 1 (f). In FIG. 1, 4 is a substrate, 5 is a compression plate, 6 is a pulley, and 7 is a weight. First, an appropriate pressure is applied to a monomolecular film of amphipathic molecules spread on the water surface (a). Lower the substrate into the water bath (b). The monolayer is attached by pulling up the substrate while moving the compression plate so as to maintain an appropriate pressure (c). The substrate is pulled up and then dried (d). The substrate is lowered again (e). This operation is repeated to obtain a cumulative film (f). The LB film thus obtained has a functional region in the film having a certain orientation and high ordering, a certain film thickness can be obtained at the molecular level, can be produced at room temperature and atmospheric pressure, and has a heterostructure construction. It has features such as being easy.
Although the LB film has many advantages as described above, it is disadvantageous for industrial use because its size is limited by the size of the substrate due to the manufacturing method.

[0003]

DISCLOSURE OF THE INVENTION The inventor of the present invention
As a result of intensive studies to overcome the drawback that the size of the LB film obtained by the B method is limited to the size of the substrate,
When applying a suitable pressure to the monomolecular film of amphipathic molecules spread on the water surface, it is possible to form a monomolecular film even if a roller with a hydrophilic surface is provided at the part that was the end of the conventional water tank. I found it. In addition, it was also found that the LB film can be produced by pulling up the monomolecular film on the water film formed on the surface of the roller and bringing it into contact with the substrate.

[0004]

The inventor of the present invention has completed the present invention as a result of further studies based on the above findings. That is, in the present invention, in producing an organic thin film by the LB method, a monomolecular film formed on a water surface is pulled up onto a water film formed on a roller having a hydrophilic surface, and this is continuously transferred to a substrate. Is a method for producing an organic thin film.

FIG. 2 shows a schematic diagram of an example of an apparatus useful for carrying out the method of the present invention. The configuration of the present invention will be described below with reference to the drawings. The method of the present invention is performed according to the following procedure.

First, an amphipathic molecule is spread on the water surface of the water tank 13, and the compression plate 12 is moved to apply an appropriate pressure. The optimum pressure varies depending on the type of amphipathic molecule, and it is preferable to obtain it in advance from the surface pressure-area isotherm curve. When the surface of the pull-up roller 14 is wet, the phenomenon that the monomolecular film slides up on the water film formed on the roller is observed. Therefore, it is necessary to increase the height at which the monomolecular film is lifted from the water surface, the height h, or the contact angle ψ between the roller and the water surface so that the monomolecular film does not get over the roller before reaching an appropriate pressure. Increasing the contact angle ψ without any limit may cause the destruction of the monomolecular film or the generation of film defects depending on the type of the amphipathic molecule.
Providing a contact angle of 30 degrees or more is effective in obtaining a finer orientation.

After the monomolecular film is formed, the pulling roller 14 is then rotated to pull the monomolecular film onto the water film formed on the roller. The compression plate 12 must be appropriately moved in accordance with the pulling up to maintain the required pressure.

A film to be a substrate is brought into contact with the monomolecular film pulled up on the water film by the transfer roller 15. As the material of the film, almost all polymers can be used except materials exhibiting extremely hydrophilicity, such as polyvinyl alcohol and polyacrylamide, and Teflon-based materials. The contact position is preferably before the monomolecular film passes over the roller. Therefore, the angle θ formed by the line connecting the centers of the transfer roller 15 and the lifting roller 14 with the water surface must be 90 degrees or less. Upon contact, the monomolecular film is transferred to the substrate and the LB film is formed there.

After transfer is carried out until the compression plate 12 moves to the vicinity of the pull-up roller 14, a new monomolecular film is formed on the compression plate 11 and the compression plate 12 is submerged in water while keeping this pressure, and put on the track 17. The transfer can be continued by continuously moving the monomolecular film by moving the film. Therefore, it is preferable that the upper portions of the compression plates 11 and 12 have a wedge shape. By repeating the above operation, a continuous LB film can be obtained.

[0010]

EXAMPLE A cumulative LB film was actually manufactured by the above method. Stearylamine (SA) was used as the film forming molecule.
The molecular structure of SA is shown below. H ₂ NCH ₂ (CH) ₁₆ CH ₃

The water temperature in the water tank of FIG. 2 was kept at 20 ° C., and SA was added dropwise as a 2.5 × 10 ⁻³ M chloroform solution and developed. The compression plate 2 is moved to a pressure of 30 dyne /
A monolayer was formed in cm. An aluminum pulling roller with a smooth surface is rotated at a peripheral speed of 10 mm / min.
The monomolecular film was pulled up by rotating with and the polyethylene film was brought into contact at the position of θ = 60 ° to transfer it to the substrate. Sequentially forming and transferring a monolayer, width 20 cm, length 60 cm
LB film was obtained. By repeating the same operation, a 5-layer cumulative LB film was obtained.

[0012]

As described above, the present invention provides a novel method for producing an LB film. That is, by pulling a monomolecular film formed on the water surface onto a water film formed on a roller having a hydrophilic surface and continuously transferring this to a substrate, the size of a conventional LB film is made larger than that of the substrate. It overcomes the drawback of being limited to the above, and contributes greatly to the industrial use of the LB film.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a process of manufacturing a conventional LB film.

[Explanation of symbols]

 1 ... Water tank 2 ... Water 3 ... Amphiphilic molecule 4 ... Substrate 5 ... Float 6 ... Pulley 7 ... Weight 8 ... LB film

FIG. 2 is a cross-sectional view showing an example of an apparatus useful for carrying out the method of the present invention 11, 12 ... Compression plate 13 ... Water tank 14 ... Pulling roller 15 ... Transfer roller 16 ... Substrate 17 ... Trajectory of movement of compression plate

Claims (1)

[Claims] 1. When producing an organic thin film by the Langmuir-Blodgett method, a monomolecular film formed on a water surface is pulled up onto a water film formed on a roller having a hydrophilic surface, and this is continuously transferred to a substrate. A method for producing an organic thin film, which comprises transferring.