JPS61287474A - Process for forming monomolecular film - Google Patents

Abstract

PURPOSE:To form monomolecular film on a base body at high rate by transferring solid monomolecular film developed on lower liquid layer to a revolvable roll by allowing the monomolecular film together with the lower layer liquid to contact closely with the roll while revolving the roll continuously. CONSTITUTION:When monomolecular film comprising amphiphilic molecule is to be formed on a web base body continuously, solution of the amphiphilic molecule in a volatile solvent is dropped from a nozzle 3 onto the surface of the lower layer liquid 2 in a lower layer liquid tank 1 to form a monomolecular layer 4 of the amphiphilic molecules on the surface of the lower layer liquid 2. The monomolecular layer 4 is then led to an end of the tank 1. A revolvable roll 10 is attached with a narrow space close to an upper edge of a side wall 1-1 of the tank 1, and a web base body 8 is traversed with tight contact to the revolvable roll 10. By this method, a monomolecular film is formed on the base body at thigh rate without dipping the base body in water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] 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.

[Conventional technology]

Conventionally, various methods have been used to form thin films of organic compounds on substrates such as glass, metal materials, metal vapor deposition films, etc. One of these methods is a method of forming a monomolecular layer of amphiphilic molecules, such as Langmuir's method. Langmulr-Blodgett, 'Physical Review'
``Physical Review'') 51, 6
64 (1937). In this method, a solution of a saturated fatty acid, which is an amphipathic molecule, dissolved in a volatile solvent such as pentene is gently dropped onto the water surface, and a monomolecular film 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 monomolecular film on the glass surface. In this case, when the glass substrate is pulled up, the hydrophilic groups facing water in the monomolecular film are attached to the substrate side, and the hydrophobic groups (or lipophilic groups) are lined up on the surface, forming a monomolecular film structure, as shown in Figure 4. (referred to as doll 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. 5 (referred to as a B-type film).

("Thin Film Handbook", pp. 268-269, edited by the Japan Society for the Promotion of Science, December 1983, published by Ohmsha).

Monomolecular layers 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, Japanese Patent Application Laid-Open No. 52-98
Publication No. 058).

In addition, the applicant has 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 to protect a monomolecular layer of saturated fatty acid or its metal salt. It was proposed that it be installed as a layer
60609).

In these improved methods, for example, as shown in FIG. A solution of fatty acids is dropped to form a monomolecular layer 4 of saturated fatty acids on the water surface, and the monomolecular layer 4 is compressed using an appropriate compression means such as a cylinder 5 partially immersed below the water surface to form a solid film. (agglomerated film) 6 and pear 1, a substrate 8 guided by a guide roller 7 provided in water
A monomolecular film 9 is formed on the surface. In this case, if a monomolecular film is formed when the base is pulled up, a B-shaped film is formed when the doll membrane is pulled in. The monomolecular layer that adheres to and extrudes from the substrate is replenished by supplying fatty acid solution from the nozzle.

[Problems to be solved by the invention]

The above technology is a major advance compared to the conventional Nototsuchi method in that it continuously forms a solid film on the lower liquid (aqueous phase), but from the perspective of industrial production, for example, When making a doll film, there is a drawback in that the moving speed of the substrate must be extremely slow during the transfer process of the monomolecular film onto the substrate. That is, when making a doll membrane,
If the pulling speed of the substrate is increased, the lower layer liquid will also be pulled up, and this will not get under the monomolecular layer, and this evaporation will cause light damage to the monomolecular layer, making it very slow and even after complete evaporation. This is because it causes defects in the density of the formed monomolecular film.

Furthermore, in these conventional methods 1 (m), since the substrate must be drawn in with the lower layer liquid (r), the entire substrate is wetted with the lower layer liquid, such as water. This is not preferable, and there are also problems such as drying takes time and effort.

In some cases, a monomolecular layer may also be attached to the [922] surface of the substrate.For example, when forming a doll film by the pulling method, a B-shaped film may be formed when the substrate is pulled into water. However, in order to prevent these from occurring, special measures must be taken to limit the range in which the monomolecular layer can migrate.

Therefore, an object of the present invention is to provide a method for forming a monomolecular film on a substrate at high speed without causing the above-mentioned problems.

Another object of the present invention is to provide a method for forming a monomolecular film on a substrate without immersing the substrate in water.

[Means for solving problems]

As a result of various studies, the inventors of the present invention found that the above object could be achieved by utilizing the principle of the bead method, and were able to obtain the present invention.

That is, the present invention provides a method for forming a monomolecular film of amphiphilic molecules on a web-like substrate, in which a solid monomolecular film spread on a lower layer liquid is coated along with an appropriate amount of the lower layer liquid at the upper edge of the end of a lower layer liquid tank. The solid monomolecular film is applied to the web-like substrate while forming a liquid pool between the upper edge and the web-like substrate, which is continuously running in a tight circle around rotating rolls arranged with a narrow gap. This is a method for forming a monomolecular film characterized by transfer.

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

FIG. 1 is an explanatory diagram showing one example of the present invention, in which a solution in which amphipathic molecules are dissolved in a volatile solvent is poured onto the surface of the lower liquid (aqueous layer) 2 in the lower liquid tank 1 from a nozzle 6. Then, a monomolecular layer 4 of amphiphilic molecules is formed on the lower liquid surface.

As volatile solvents, hexane, chloroform, benzene, etc. are used.As amphiphilic molecules, when used as a protective layer, tridecanoic acid, myristic acid, hentadecane'flit, lumitic acid, margaric acid, stearic acid are used. , nonadecanoic acid, arachidic acid, etc., with a carbonation number of 13 or more
21 linear fatty acids or these Li, Na, M
Salts such as g, Ca, and Ba 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 Ca'', Cd''I Ba'',
It contains divalent metal ions such as Mg20, and its pH is adjusted by adding hydrochloric acid and hydrogen carbonate.

Next, the monomolecular layer 4 formed on the lower liquid level is compressed and guided to one end of the tank 1. For this purpose, a cylinder 5 made of a hydrophobic material such as Teflon or polyethylene or a material such as Norex glass or aluminum alloy is partially immersed in water and rotated in the direction of the arrow to form a monomolecular layer on the surface. 4 is sent to the application area and compressed to form a solid film layer 6. Note that the means for compressing the monomolecular layer is not limited to the above-mentioned rotating roller, but other means may also be used. application area,
In other words, the side wall 1-1 at the end of the lower liquid tank on the side where the monomolecular layer and dl are compressed is almost at the same level as the sewage layer. There is. A rotating roll 10 is provided close to the upper edge of the side wall 1-1, keeping a narrow gap from the upper edge, and during operation,
The web-like substrate 8 is run in the direction of the arrow in close contact with the rotating roll 10.

During operation, while the web-like substrate 8 is traveling, the lower layer liquid 2 is
The level of the lower layer liquid is increased by adding an appropriate amount of water or by placing an object such as a model in a specific volume, and an appropriate amount of the lower layer liquid flows from the upper edge of the end side wall 1-1 together with the solid monomolecular film. O/9 - In a flowing state, the base 8 supported by the rotating roll 10 supports the liquid and maintains a liquid pool (bead) between the upper edge and the base 7, and solid molecules The film is transferred onto the surface of the substrate 8.

FIG. 1 shows the base body 8 moving upward in the liquid pool, in this case the roll 10 and the side wall 1-
By reducing the pressure on the outer side 11 of 1 (referred to as the rear part in the running direction of the substrate), the lower layer liquid is prevented from entering between the substrate and the solid monomolecular film and splintered, and the running of the substrate is prevented. 1. An enlarged schematic view of the upper edge of the end side wall 1-1 of the upper layer tank of FIG. 1 is shown in FIG. In this case, a doll membrane (Fig. 4) is formed 1. Furthermore, as shown in Fig. 2 (A), once the side wall 1-1 is
If a liquid pool forms between the upper edge and the substrate 80, then even if the level of the lower liquid is slightly lower than that of the second edge, a monomolecular layer can be deposited on the substrate as shown in FIG. 2(C). Transfer is often maintained, and in this case, the tendency of the lower layer liquid to be transferred to the substrate along with the monomolecular layer or to be sucked into the vacuum section at the rear of the running direction is suppressed, resulting in a more stable operation. I found out that you can do it. When performing such an operation, it is desirable that the difference between the liquid level and the upper edge level of the side wall be within 1 d of 5 mm, but it may be determined as appropriate depending on the amphipathic substance used and the properties of the lower layer liquid.

FIG. 2(B) is an enlarged schematic diagram showing an example of forming a J5B type film (FIG. 5) according to the present invention, in which the rotating roll 6 is rotated in the opposite direction to that in FIG. 1. and run the web-like support in the direction of the arrow. In this embodiment, in order to prevent the lower layer liquid from leaking, the roll 10
and the outside of the side wall 1-1 (referred to as the front part in the running direction of the web-like substrate in the present invention) is pressurized. Further, by applying pressure in this manner, the running speed of the web, and hence the formation speed of the solid monomolecular film can be increased. Note that the relationship between the liquid level and the upper edge level of the side wall is the same as in the case of forming the A film.

In the case of a vapor-deposited tape, for example, a vapor-deposited magnetic recording medium having a ferromagnetic thin film on which a polyethylene terephthalate film K Co -Ni alloy is vapor-deposited is used as the substrate 8, and the saturated fatty acid on the ferromagnetic thin film is A retention layer consisting of a monomolecular film of is formed.

The substrate to be used in the present invention is not limited to those mentioned above, but may include other types of ferromagnetic thin films, such as electrolytic plating,
Alternatively, it may be a magnetic recording medium having a thin film formed by electroless plating or the like, and not only a magnetic recording medium but also other materials f may be used.

Also, if desired, heating means can be used in the application area to evaporate the monolayer of solvent and assist in forming a solid monolayer.

Furthermore, by repeating the above operations, a multilayer consisting of a desired type of monomolecular layer can be formed.

Note that the rotating roll 10 and the paddle are preferably as small as possible; for example, when the base width is 50 to 100 cWL, the diameter of the roll is preferably about 15 to 25 mm.

〔Example〕

Next, an example will be described in which the present invention is applied to a case where a protective layer is provided on a vapor-deposited magnetic tape.

A polyethylene terephthalate film with a thickness of 25 μm and a width of 5011 m was installed in a vacuum evaporation apparatus, and Co was 75% by weight.
, Ni with a composition of 25% by weight was evaporated onto the film to a thickness of 0.6 μm from an evaporation source filament at a vacuum degree of 5.0 + 10 Torr.

A solution of 0.005.9 palmitic acid dissolved in 100 ee of benzene is dropped onto the water surface of the lower liquid tank 1 of the apparatus shown in FIG. 1 to form a monomolecular layer, which is then compressed with a Teflon cylinder 5. It was made into a solid monolayer.

The rotary roll 10 is a stainless steel roll with a diameter of about 1 am. The vapor-deposited film is continuously run by the roll 10, the water level of the lower liquid tank 1 is gradually raised, and the rear part 11 of the film is reduced in pressure by 1 to 5 mm of water column. While doing so, a small amount of water is automatically flowed from the upper edge of the side wall 1-1 together with the solid monomolecular film to create a pool of liquid between the upper edge and the film, and then the liquid level is lowered by about 1 inch from the upper edge. In this state, the monomolecular film was transferred onto the film surface to continuously form a protective layer consisting of a monomolecular film of I#lumitic acid. In this case, the number of revolutions of the rotary roll 10 is 22 r, p, m, "l", and the running speed of the tape is 10 ml/min. A good protective layer can be formed.

〔Effect of the invention〕

According to the present invention, it is possible to form a monomolecular film on one substrate at high speed using the Langmuir method without accompanying the lower layer liquid, and the monomolecular film can be formed without drawing the substrate into water. f, it is possible to form a desired monomolecular film without causing phenomena such as the substrate becoming wet with water or the monomolecular layer adhering to the notch layer of the substrate! Wear.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one example of the present invention, FIGS. 2(A), (B), and (C) are explanatory diagrams showing aspects of monomolecular film formation in the present invention, and FIG. FIGS. 4 and 5 are explanatory drawings showing the molecular film type method, and FIG. 1 is an explanatory drawing showing the principle of monomolecular film formation. 2... Lower layer liquid, 3... Nozzle, 4... Monomolecular film layer, 5... Cylinder, 6.9... Solid monomolecular film, 8
... Base body, 7, 10 ... Rotating roll.

Claims (3)

[Claims] (1) In a method of forming a monomolecular film of amphiphilic molecules on a web-like substrate, a solid monomolecular film developed on a lower layer liquid is placed in a narrow space between the upper edge of the lower layer liquid tank and an appropriate amount of the lower layer liquid. Transferring the solid monomolecular film to the web-like substrate while forming a liquid pool between the upper edge and the web-like substrate, which runs continuously while closely contacting rotating rolls arranged with a gap. A method for forming a monolayer characterized by: (2) The method for forming a monomolecular film according to claim (1), wherein the web-like substrate runs upward in a portion where a liquid pool is formed, and the pressure is reduced at the rear of the substrate in the running direction. (3) A method for forming a monomolecular film according to claim (1), in which a web-like substrate runs downward in a portion where a liquid pool is formed and pressurizes the front part of the substrate in the running direction. .