JPS6227077A - Formation of solid monomolecular film - Google Patents

Abstract

PURPOSE:To stabilize the conditions of operation and maintenance by introducing a soln. of amphipathic molecules in a volatile solvent onto the liq. surface of form a monomolecular layer and generating an air current in the vicinity of the liq. surface from the monomolecular region to the solid monomolecular film region to impress the surface pressure of the monomolecular layer. CONSTITUTION:A soln. of amphipathic molecules (e.g., palmitic acid) in a volatile solvent (e.g., benzene) is introduced onto the surface of pure water, an aq. soln. of an inorg. salt, etc., to form a monomolecular layer 4, the solvent is removed and the monomolecular layer 4 is simultaneously compressed to form a solid monomolecular film 6. In this method, an air current is generated by an air blow-off nozzle 10 in the vicinity of the liq. surface from the monomolecular layer region to the solid monomolecular layer 4, and the surface pressure is applied for the layer 4. Consequently, the conditions of operation and maintenance can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a method for continuously forming a monomolecular film of amphipathic molecules on a web-like substrate or on a layer provided on a web-like substrate. In particular, it relates to a method for forming a solid monolayer.

[Conventional technology]

Conventionally, various methods have been used to form thin films of organic compounds on substrates such as glass, metal materials, and metal vapor deposited films. Prop, 1 physical rep
--” (Langmuir-Blodgett,'
Physical Review'') 51,664 (
1937). In this method, a solution of the amphipathic molecule, sulfuric acid, dissolved in a volatile solvent such as benzene, is gently dropped onto the water surface, and a monomolecular layer is left behind after the solvent evaporates.

After compressing the monomolecular layer thus formed to a predetermined surface pressure, the glass substrate is immersed in water and pulled up to form a solid monomolecular film on the glass surface. This 93
g When the glass substrate is pulled up, as shown in Figure 6, the hydrophilic groups facing water in the monomolecular film are attached to the substrate side, forming a monomolecular film with hydrophobic groups (or lipophilic groups) lined up on the surface ( (referred to as A-type membrane).

Further, when a glass substrate is immersed, a monomolecular film structure is formed in which the hydrophobic groups (or lipophilic groups) are attached to the substrate side and the hydrophilic groups are arranged on the surface as shown in FIG. 4 (referred to as a B-type film).

("Thin Film Han P Book", pp. 268-269, Japan Science Promotion Gold Line, December 1981, ■Published by Ohmsha).

Solid monomolecular films produced by such methods have recently come to be used as insulating layers in fields such as electronics, and various improvements have been proposed (for example,
-98038).

The applicant has also applied this method to a magnetic recording medium in which a thin ferromagnetic alloy film has been formed on a support by vapor deposition or electrolytic plating, etc., to apply a monomolecular film of saturated fatty acid or its metal salt as a protective layer. ←Unexamined Japanese Patent Publication 1983-
Publication No. 30609@).

In these improved methods, for example, as shown in FIG. 2, stearic acid dissolved in a volatile solvent such as benzene or chloroform, etc.
A solution of a saturated fatty acid such as cermitic acid is dropped to form a monomolecular layer 4 of saturated fatty acid on the water surface, and the monomolecular layer 4 is formed by suitable compression means such as a cylinder 5 partially immersed below the water surface. It is compressed to form a solid monomolecular film (agglomerated film) 6, and a protective layer 9 of the monomolecular film is formed on the surface of the substrate 8 guided by guide rollers 7 provided in water. In this case, as shown in the sixth factor, FIG. 4, if a monomolecular film is formed when the substrate is pulled up, a B-shaped film will be formed when the doll membrane is pulled in. The monomolecular layer that adheres to the substrate and spills out is replenished by supplying fatty acid solution from the nozzle 6.

In the methods disclosed so far, the method of forming a solid monolayer by applying surface pressure to a monomolecular layer of amphiphilic molecules formed on a lower liquid (aqueous phase) includes, for example, the above-mentioned specific method. In the method exemplified in Japanese Publication No. 56-30609, surface pressure is applied to the monomolecular layer on the liquid surface by pressing the barrier existing on the liquid surface with a nonone, and In the publication, some parts are above the liquid level,
By rotating a cylinder installed horizontally, a part of which is below the liquid surface, the monomolecular layer formed on the liquid surface is placed on the cylinder above the liquid surface and sent to the application area. A method is disclosed in which a solid monomolecular film is formed by applying surface pressure to the film.

[Problems to be solved by the invention]

However, in all of these methods, the pressure member is above the liquid surface, so great care must be taken to avoid causing ripples on the liquid surface and disturbing the monomolecular layer or solid monomolecular film. Since the pressure member often comes into contact with the monomolecular film, sometimes the amphiphilic molecules may be attached and detached unevenly, preventing smooth transfer of the monomolecular layer to the coating area. , it was necessary to consider the selection of the material of the pressure member and its operation and maintenance. An object of the present invention is to provide a method for forming a solid monolayer film which eliminates the above-mentioned drawbacks and provides stable conditions for operation and maintenance.

[Means for solving problems]

As a result of various studies, the inventors of the present invention discovered that the above purpose could be achieved by utilizing air flow, and were able to obtain the present invention.

That is, the present invention introduces a volatile solvent solution of amphiphilic molecules onto the liquid surface to form a monomolecular layer, and removes the solvent and compresses the monomolecular layer to form a solid monomolecular film. The method for forming the monomolecular layer is characterized by applying surface pressure to the monomolecular layer by generating an air flow on the liquid surface from the monomolecular layer region toward the solid monomolecular film region in close proximity to the liquid surface. This is a method for forming a solid monolayer.

In the present invention, when used as a protective layer, amphiphilic molecules such as tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, etc. Chain type fatty acids or these Li.

Salts such as Na, K, Mg, Ca, Ba, etc. are used.

As the volatile solvent, hexane, chloroform, benzene, etc. are used.

Generally, pure water or an aqueous solution of an inorganic salt is used as the lower layer liquid. Commonly used lower liquids are Cax+, Q
d'', Ba''p Contains divalent metal ions such as Mg2+, and its pH is adjusted by adding hydrochloric acid and sodium hydrogen carbonate.

In addition, as a method for generating an air flow on the liquid surface from the monomolecular layer region to the solid monomolecular film region near the liquid surface, there are not only methods for simply blowing air, but also This also includes a method in which an exhaust port is set in the monomolecular layer region and the inlet surface thereof is opened into the monomolecular layer region. The important thing is the selection of wind speed, and measures and adjustments must be made to prevent waves from forming on the liquid surface.

[Effect]

The air flow according to the present invention is not only effective in compressing the monolayer to form a solid monolayer (but also in promoting the removal of volatile solvent solutions). The suction force produced by the air blowing nozzle also works as effectively as the air blowing nozzle.

〔Example〕

The present invention will be described below with reference to a case in which a protective layer is provided on a vapor-deposited magnetic recording medium, but the present invention is not limited to this.
Of course, it can be applied to the formation of monomolecular films in electronics and other fields.

FIG. 1 shows an embodiment of the present invention, in which four jets 100c are ejected from a nozzle 6 onto the surface of the lower liquid 2 filled in the lower liquid tank 1.
A solution containing 0.0059 palmitic acid per c was dropped to form a monomolecular layer 4.

The monomolecular layer 4 is formed by receiving the breeze blown from the air blowing nozzle 10 uniformly across the width direction of the tank (same as the width direction of the coating device), from the monomolecular layer region to the solid monomolecular film region. It is compressed while promoting the evaporation of the solvent.

A heating lamp was also used to promote evaporation of the solvent. Then, an exhaust port 11 is provided near the boundary between the monomolecular layer region and the solid monomolecular film region.
was set to suck air and solvent gas from the air blowing nozzle. Perhaps due to the suction force of the exhaust port 11, the monomolecular layers aggregate together near this location, forming a solid monomolecular film 6.
was formed. Further, at the end of the lower liquid tank, a solid monomolecular film 6 was applied as a protective film 9 onto a web-like substrate 8, which was a magnetic recording medium, using a bead coat application device 16. The wedge-shaped substrate 8, which was the magnetic recording medium at this time, was as follows. That is, the vacuum evaporation equipment has a thickness of 25 μm.
A polyethylene terephthalate film with a width of 50 cm and a composition of 0075% by weight and 25% by weight of Ni was placed under a vacuum of 5.0 + 10'' from an evaporation source filament.
It was deposited on the film in Torr to a thickness of 0.3 μm.

〔Effect of the invention〕

According to the present invention, since the action of air flow is used to compress the monomolecular layer, there is no need for a pressurizing member as in the past, and the unstable element caused by this is removed, making it possible to stabilize operation and maintenance conditions. done. In addition, the quality of the solid monomolecular film as a protective film was also improved because the removal of the solvent by the air flow was also promoted.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention. FIG. 2 is an explanatory diagram showing an example of a conventional method. FIG. 6 and FIG. 4 are explanatory diagrams showing the principle of monomolecular film formation. 1... Lower layer liquid tank, 2... Lower layer liquid, 6...
... Nozzle, 4 ... Monomolecular layer, 5 ... Cylinder, 6 ... Solid monomolecular film, 7 ...
・Rotating roll, 8...substrate (magnetic recording medium),
9... Protective film, 10... Air blowing nozzle, 11... Exhaust port, 12... Heat lamp, 16... Coating device. I''

Claims (1)

[Claims] A method of forming a monomolecular layer by introducing a volatile solvent solution of amphiphilic molecules onto a liquid surface, removing the solvent and compressing the monomolecular layer to form a solid monomolecular film, A solid monolayer characterized in that the surface pressure of the monomolecular layer is applied by generating an air flow on the liquid surface from the monomolecular layer region toward the solid monomolecular film region close to the liquid surface. Molecular film formation method.