JPH0558015B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing an organic thin film having a novel molecular orientation. More specifically, (i) having one straight chain hydrophobic group containing two or three straight chain hydrophobic groups or a rigid part in the chain;
and an organic compound having an ionic group and (ii) an aqueous solution containing a polymer having an ionic group having an opposite charge to the ionic group possessed by the organic compound in () above to form an interface. The present invention relates to a method for producing an organic thin film, which comprises immersing a substrate in the aqueous solution and pulling it up in a direction perpendicular to or at an angle to the substrate, thereby forming an organic thin film on the substrate. (Prior Art) In recent years, attempts have been made to apply organic thin films to a wide range of applications such as separation membranes, sensors, display materials, and electronic devices. In particular, organic thin films with molecular orientation are considered to be extremely important for organizing molecules and constructing functional molecular groups. To date, the most effective method for creating organic thin films with molecular orientation is to develop organic compounds having both hydrophilic groups such as ionic groups and hydrophobic groups such as linear alkyl groups on the surface of the aqueous phase. A method is used in which a substrate is immersed in the aqueous phase and pulled up to form an organic thin film on the substrate, and the organic thin film formed by this method is called a Langmuir-Blodget film. However, in conventional Langmiur Blossom membranes, the organic compounds used in many cases contain hydrophilic groups such as ionic groups in their molecules, and they generally have relatively low molecular weights of 1000 or less. Because of the large amount of carbon dioxide, there is a problem that it easily disintegrates or changes its structure when used in water or under heated conditions, and its field of application has been extremely limited. (Means for Solving the Problems) As a result of various studies in order to obtain an organic thin film with molecular orientation that overcomes these drawbacks, the present inventors found that (i) two or three linear chains having one straight chain hydrophobic group containing a hydrophobic group or a rigid part in the chain,
and an organic compound having an ionic group and (ii) an aqueous solution containing a polymer having an ionic group having an opposite charge to the ionic group possessed by the organic compound in () above to form an interface. It is possible to form an organic thin film with excellent water resistance and heat resistance on the substrate by immersing the substrate in the aqueous solution in a direction perpendicular to or at an angle to and pulling it up to form an organic thin film on the substrate. We have discovered that this is the case, and have completed the present invention. One of the main components used in the present invention is an organic compound that has two or three straight-chain hydrophobic groups, or one straight-chain hydrophobic group that includes a rigid part in the chain, and also has an ionic group. (hereinafter abbreviated as linear organic compound). In the present invention, the ionic group is defined as a general term for acidic groups or basic groups. Here, acidic or basic means Brønsted acid or Brønsted base; acidic groups generally include sulfone groups, carboxyl groups, phosphoric acid groups, phenolic hydroxyl groups, and salts thereof; basic groups include Generally, amino groups, substituted amino groups, quaternary ammonium groups, and salts thereof are preferably used. In the present invention, the linear hydrophobic group has a carbon number of 4 to
30 straight chain alkyl groups or halogen-substituted derivatives thereof. In addition, the linear hydrophobic group referred to in the present invention refers to a completely linear hydrophobic group, as well as one with a carbon number of 2.
It is also used in the sense of including branched things with up to 100 branches. One of the linear organic compounds of the present invention has two or three linear hydrophobic groups. If the number of linear hydrophobic groups is one, the resulting organic thin film will not have sufficient water resistance, and if it has four or more, there will be difficulties in obtaining raw materials and in synthesis. Moreover, another one of the linear organic compounds of the present invention is
It has one straight chain hydrophobic group that includes a rigid part in the chain. In the present invention, the rigid moiety refers to the following groups. Direct bond or carbon-carbon multiple bond, carbon-
A divalent group composed of at least two aromatic rings connected via a nitrogen multiple bond, a nitrogen-nitrogen multiple bond, an ester bond, an amide bond, etc. Specific examples of such groups include, for example, Examples include divalent groups such as. A divalent group in which two aromatic rings have multiple bonds or a single bond between multiple atoms, and the rotation of which is energetically constrained; specific examples of such groups include: for example, Examples include divalent groups such as. A divalent group in which aromatic rings form a condensed ring, and when this condensed ring is stacked between multiple molecules, the rotation thereof is sterically constrained to each other,
Specific examples of such groups are: Examples include divalent groups such as. The number of carbon atoms in the straight chain hydrophobic group of a straight chain organic compound having one straight chain hydrophobic group containing a rigid part in the chain is:
It means the number of carbon atoms in the portion excluding the rigid portion and the bonding portion between the rigid portion and the linear hydrophobic group. The bond between the rigid portion and the linear hydrophobic group is generally preferably a carbon-carbon single bond, an ester bond, or an ether bond. The reason for limiting the number of straight chain hydrophobic groups that contain a rigid part in the chain is that if the straight chain hydrophobic group contains two
This is because if the number is more than 1, it becomes extremely difficult to synthesize, and it becomes difficult to stably develop on the water interface when forming a thin film. The linear organic compound of the present invention is not particularly limited as long as it satisfies the above requirements, and known compounds can be used. Representative ones that are generally suitably used are specifically shown below. However, R ¹ and R ² are the same or different straight chain alkyl groups having 6 to 30 carbon atoms or halogen-substituted products thereof, and R ³ and R ⁴ are the same or different alkyl groups having 1 to 4 carbon atoms, or It is a substituted product with a halogen atom and/or a hydroxyl group. However, R ¹ and R ² are the same as above, and A is (-B)l(CH ₂ (-k (however, B is

【formula】

【formula】

[expression] or

[Formula], is 0 or 1, and k is a positive integer. ) and h,
i is a positive integer. R ³ , R ⁴ , R ⁵ are the above R ³
and R ⁴ . However, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and A are the same as above, i is 1 or 2, and m is 0 or 1. However, R ¹ , R ² , R ³ , R ⁴ and R ⁵ are the same as above, and n is a positive integer. However, R ³ , R ⁴ and R ⁵ are the same as above,
R ⁶ is an alkyl group, alkyloxy group, or alkyloxycarbonyl group having 4 to 30 carbon atoms, or a halogen-substituted product thereof, and D is

【formula】

【formula】

【formula】

[Formula] (However, F is -N=CH-, -N=N-, -
CH=CH−,

【formula】

【formula】

【formula】 【formula】

[Formula] −NHCH ₂ −,

【formula】

【formula】

[expression] or

[Formula] p is 0 or 1. ) E is (−CH ₂ −) _q or −
O-( _CH2 )-) _r . (However, q and r are positive integers.) In the above general formulas [B], [D] and [E], k,
Although n, q and r may be any positive integer, they are generally preferably 1 to 16 from the viewpoint of easy availability of raw materials. In addition, in the above general formula [B], h and i
may take any positive integer without any restriction, but is generally preferably from 1 to 4 from the viewpoint of easy availability of raw materials. Furthermore, the above general formulas [A], [B], [C],
[D] and [E], R ¹ , R ² , R ³ , R ⁴ , R ⁵ and
Examples of the halogen atom in the halogen-substituted alkyl group represented by R ⁶ include fluorine, chlorine, bromine, and iodine atoms. Another component used in the present invention is a water-soluble polymer (hereinafter also simply referred to as an ionic polymer) having an ionic group with an opposite charge to the ionic group possessed by the organic compound. The polymer is not particularly limited as long as it has the above specifications, and any known polymer can be used. Considering the stability of generally obtained organic thin films, those having a molecular weight in the range of 5,000 to 10,000,000 are preferable. Further, the monomer used to obtain the above polymer is not particularly limited as long as the obtained polymer has the above properties. Examples of monomers that are generally suitably used are as follows.
Namely, monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, glutamic acid, and aspartic acid; styrene sulfonic acid, vinyl sulfonic acid, alkenesulfonic acid, and t-butylacrylamide sulfonic acid. Monomers having a sulfonic acid group such as; monomers having a phosphoric acid group such as vinylphosphonic acid, acryloyloxyalkylphosphonic acid, methacryloyloxyalkylphosphonic acid;
Phenol monomers such as vinylphenol; cationic monomers such as lysine, ethyleneimine, vinylpyridine, dimethylaminopropylmethacrylamide, and substituted derivatives obtained by substituting these monomers with substituents are preferably used. Moreover, the vinyl monomer copolymerizable with the monomer having an ionic group is not particularly limited, and any known vinyl monomer can be used as long as the resulting copolymer imparts the properties described above. Typical examples that are generally preferably used include, for example, olefin compounds such as ethylene, propylene, and butene; halogen derivatives of olefin compounds such as vinyl chloride and hexafluoropropylene; diolefin compounds such as butadiene and bentadiene. and its halogen derivatives; aromatic vinyl compounds such as styrene, chlorostyrene, and vinylnaphthalene; vinyl ester compounds such as vinyl acetate; acrylic acids such as methyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, acrylamide, and methacrylamide; Examples include methacrylic acid derivatives; unsaturated nitrile compounds such as acrylonitrile; and vinyl ether compounds such as methyl vinyl ether. The general formula of the ionic polymer generally suitably used in the present invention is as follows. Polymer with carboxyl group However, R is a hydrogen atom, an alkyl group or a carboxymethyl group, and X is a _-CH2- group,

[Formula] Group or

[Formula] group (wherein R ¹ is an alkyl group or an aryl group), and M is a hydrogen atom, a metal atom, or a lower ammonium. c is an integer from 0 to 2, and a and b are 0 or 1. Here, when a is 0, b=1,
c=0, R is a hydrogen atom, and when a is 1, b=0, c=0-2, R is a hydrogen atom, an alkyl group or a carboxymethyl group. Polymers with sulfonic acid groups However, R'' is a hydrogen atom or an alkyl group, and Y is

【formula】

[Formula] -0- or (-CH ₂ -) _e (where e is a positive integer), M is a hydrogen atom, a metal atom or a lower ammonium,
d is 0 or 1. Polymers with phosphate groups However, R is an alkyl group, and Z is

[Formula] (where g is a positive integer), M is a hydrogen atom, a metal atom or a lower ammonium, and f is 0 or 1. In the above general formulas [], [] and [], R,
The alkyl groups represented by R′, R″ and R are:
Although any carbon number can be used without being limited to the number of carbon atoms, those having 1 to 4 carbon atoms are generally preferred. In addition, in the above general formulas [] and [],
e and g may be positive integers, but are preferably integers of 1 to 4 from the viewpoint of easy availability of raw materials. As a method for producing the ionic polymer described above, a method of homopolymerizing the above-described monomers having an ionic group or copolymerizing two or more thereof is adopted. Moreover, a polymer having an ionic group can also be obtained by copolymerizing the above-mentioned monomer having an ionic group and a copolymerizable vinyl monomer. Moreover, a method of introducing ionic groups into a polymer capable of introducing ionic groups by chemically reacting the same is often suitably employed. For example, a method of obtaining a polymer having a carboxyl group by hydrolyzing a single or copolymer of carboxylic anhydride such as maleic anhydride or itaconic anhydride, or
Examples include a method of obtaining a polymer having a sulfonic acid group by subjecting polyvinyl alcohol to a sulfuric acid esterification reaction. In addition to the above-mentioned polymers, natural polymers having ionic groups are also suitably used as the ionic polymer in the present invention. Examples of natural polymers having ionic groups that are generally preferably used in the present invention include alginic acid, sodium alginate, carboxymethyl cellulose, heparin, chondroitin sulfate, and derivatives thereof. The substrate used in the present invention may be selected from known materials depending on the intended use of the resulting thin film. Although any substrate may be used for applications in which an organic thin film is used separately from a substrate, which will be described later, in many cases the organic thin film is generally used as is with the organic thin film formed on the surface of the substrate. In this case, it is necessary to select a substrate depending on the usage type or required function. The substrate materials that are generally suitable for use are:
For example, the surface of the substrate does not necessarily have to be smooth when it is made of a polymeric material, glass, metal ceramic, or the like. For example, when used as a separation membrane, a porous membrane may be used as a substrate, and the organic thin film formed on the surface of the porous membrane may be used as it is without peeling. In the present invention, in order to form an organic thin film on the substrate, a linear organic compound having an opposite charge to the ionic group of the polymer is developed on the surface of the aqueous solution in which the ionic polymer is dissolved, An interface between the two is formed, and the substrate is immersed and pulled up in a direction perpendicular to or at an angle to the interface, thereby forming the organic thin film on the substrate. To carry out this operation, a linear organic compound is spread on the surface of an aqueous solution, and when the substrate is immersed and pulled up, the substrate is immersed in the aqueous solution while applying horizontal pressure to the interface. And it is suitable to pull it up. The pressure in the horizontal direction is not particularly limited, and may be determined in advance and employed as necessary. Generally, it is preferable to maintain the surface pressure at the interface at 10 dyn/cm or more, preferably 20 dyn/cm or more and 50 dyn/cm or less.
The means for keeping the surface pressure within a certain range is not particularly limited, but for example, the means for keeping the surface pressure within a certain range
(1984), in particular using an apparatus similar to that shown in FIG. 3 thereof. This type of device is already commercially available and readily available. When developing a linear organic compound on the surface of an aqueous solution containing an ionic polymer, these linear organic compounds are generally solid, and in this case, the solution is dissolved in an organic solvent and then dissolved in an aqueous solution. A method in which the solvent is evaporated after being developed on the surface is preferably employed. The organic solvent used here is not particularly limited as long as it can dissolve the linear organic compound. Solvents that dissolve linear organic compounds vary depending on the type of linear organic compound, but include hexane, heptane, methylene dichloride, chloroform, trichloroethane, tetrachloroethane, benzene, toluene, xylene, chlorobenzene,
Solvents that are substantially immiscible with water, such as dichlorobenzene, trichlorobenzene, and ethyl acetate, can be suitably used alone or in combination. Furthermore, it is also possible to use a water-miscible solvent such as methanol, ethanol, acetone, and tetrahydrofuran in an amount of 50% by volume or less based on the water-immiscible solvent. In the present invention, it is desirable that the amount of the ionic polymer dissolved in the aqueous solution phase be equal to or more than the equivalent amount of the ionic group based on the linear organic compound developed on the water surface. If the amount of the ionic polymer is less than this value, the resulting organic thin film may not have sufficient water resistance or heat resistance. In addition, when deploying an organic compound on the water surface, after deploying it in an amount such that the water surface area per molecule of the linear organic compound is 200 Å ² or more, Most preferably, a method is employed in which a predetermined surface pressure is reached while applying more pressure and reducing the surface area of water on which the linear organic compound is developed. The relationship between the water surface area and surface pressure per molecule of the linear organic compound used in the present invention differs slightly depending on the type of linear organic compound, temperature, and type of ionic polymer that is another component, so , it is desirable to find that relationship. In general, pressure is applied until the water surface area per molecule of the linear organic compound used in the present invention is 100 Å ² to 50 Å ² , and a surface pressure of 10 dyn/cm to 50 dyn/cm, which is suitably employed in the present invention, is applied. There are many things you can get. It is preferable that the temperature employed in carrying out the present invention is appropriately determined in advance according to various conditions. Generally, it is sufficient to select the temperature from the temperature at which the aqueous phase solidifies, that is, 0°C, to the temperature at which it becomes difficult for the organic compound to stably exist on the surface of the aqueous phase, for example, about 50°C. Further, in the present invention, the angle at which the substrate is immersed in the aqueous solution and pulled up is most preferably perpendicular to the horizontal direction, but it may also be at an angle to the horizontal direction as long as the pulling is possible. . In general, the angle can be up to a maximum of several degrees, for example 2 to 3 degrees, with respect to the horizontal direction, but the angle may be determined in advance depending on the ease of forming an organic thin film on the substrate surface or industrial implementation. Then, you can adopt it. The present invention is carried out under the conditions as described above.
An organic thin film is formed on the substrate by dipping the substrate from above perpendicularly or at an angle to the water/linear organic compound interface and pulling it up. In this case, it is desirable that the linear velocity is 10 mm/sec or less, preferably 3 mm/sec or less. If the dipping and pulling speeds are extremely high, it may be difficult to form an organic thin film on the substrate with good reproducibility, so care must be taken. (Effects) The organic thin film formed on a substrate by the method of the present invention has good water resistance and heat resistance. Although it is possible to develop a linear organic compound such as the one used in the present invention on the water surface and form a thin film with molecular orientation on the substrate (Chemistry
Letters. By dissolving the linear organic compound and ionic polymer in advance,
They discovered that the organic thin film formed on the substrate is extremely stable. Furthermore, the organic thin film obtained by the method of the present invention has a specific molecular orientation. This can be directly verified by X-ray diffraction of the resulting organic thin film. In addition, if the amount of the obtained organic thin film is not sufficient for X-ray diffraction, the contact angle of water and organic solvent to the organic thin film is measured, and this value is applied to the water surface using only the linear organic compound. The contact angle to the organic thin film developed and formed on the substrate (the organic thin film obtained by this method has a specific molecular orientation)
Chemistry Letters, 915 (1984). ), and by comparing the contact angle with a film-like material having substantially the same chemical composition as the present invention and having no orientation, which was produced by other methods, such as a normal solvent evaporation method, to prove the proof more easily. can be done. In general, the organic thin film obtained by the method of the present invention has a contact angle comparable to that of the organic thin film obtained above, and has a higher contact angle with water than the film-like material obtained above, even though the chemical composition is almost the same. It has large corners and is hydrophobic. (Function) The organic thin film obtained by the method of the present invention has good water resistance and heat resistance. Since the polymer is present in water, the ionic polymer is introduced into the organic thin film obtained by forming ion pairs between the linear organic compound and the ionic polymer, making it appear as if the linear organic compound was directly polymerized. It is thought that water resistance and heat resistance such as these are imparted. The fact that the organic thin film obtained by the method of the present invention contains the ionic polymer used during production together with the linear organic compound means that the obtained organic thin film can be measured by Fourier transform infrared absorption spectrum or electron
It is revealed by analytical means such as Spectroscopy for Chemical Analysis (hereinafter simply abbreviated as ESCA). In particular, ESCA is an effective means for analyzing thin films such as those obtained by the present invention. EXAMPLES Examples are given below to explain the present invention more specifically, but the present invention is not limited to these Examples. Further, the following examples were carried out using a LUD type Langmiur membrane manufacturing apparatus manufactured by Kyowa Kagaku. The water tank of this device has an opening area of 15 cm x 70 cm and a depth of 6 cm, and is designed so that pressure can be applied from the side to the water surface by a movable float. All the water used was purified by ion exchange and reverse osmosis. Examples 1 to 6 1 g of potassium polystyrene sulfonate to 100 ml
of water, and 5 ml of it was added to the water tank section (water temperature 25°) of Langmiur membrane manufacturing equipment. 10.0 mg of the linear organic compound shown in Table 1 was dissolved in 10 ml of the organic solvent shown in Table 1, and 50 μm of the solution was spread on the water surface and allowed to stand for 5 minutes to evaporate the organic solvent. After that, the porous membrane (Nucrepore NP300, pore diameter 0.3 μm) was immersed and pulled up from the vertical direction 10 times at a speed of 0.5 mm/sec while applying pressure from the side with a movable float and keeping the surface pressure at 30 dyn/cm. An organic thin film was formed on the surface of the porous membrane. The obtained organic thin film was analyzed by ESCA. The analysis results were as shown in Table 1. Furthermore, in order to investigate the properties, water resistance, and heat resistance of the obtained organic thin film, the contact angle of water with respect to the organic thin film was measured at 20°C. The water contact angle was measured immediately after manufacture, after being left in water at 60°C for 1 hour to check water resistance, and in air to check heat resistance.
Measurements were also made for those heat-treated at 100°C for 1 hour. The results are shown in Table 1. Table 1 shows, as comparative examples, organic thin films made of linear organic compounds formed on porous membranes in exactly the same manner as in Examples 1 to 6, except that potassium polystyrene sulfonate was not used. The contact angle values for are also listed. By comparing the water contact angle values in Examples and Comparative Examples, it is clear that the organic thin films obtained in Examples have excellent water resistance and heat resistance.

【table】

[Table] Comparative Examples 1 to 6 5 mmol of each of the linear organic compounds used in Examples 1 to 6 was ultrasonically dispersed in 50 ml of water at 70°C. 20 ml of an aqueous solution containing 5 mmol of potassium polystyrene sulfonate in monomer units.
was added and stirred at room temperature overnight. The resulting precipitate was collected, washed repeatedly with methanol, and then dried under vacuum. The composition of the obtained precipitate was determined by elemental analysis. The results are shown in Table 2. From the results in Table 2 and the analytical results of Examples 1 to 6 in Table 1, it is clear that Examples 1 to 6 and Comparative Examples 1 to 6 each have substantially the same composition. After dissolving 0.5 g of the precipitate obtained in the comparative example in 10 ml of chloroform,
The mixture was cast onto a glass plate, and chloroform was evaporated to obtain six types of film-like products. It was confirmed that these film-like materials were non-oriented by performing X-ray diffraction from the surface direction and the cross-sectional direction of the film-like materials. The water contact angle values for these film-like materials are also listed in Table 2. When these results are compared with the water contact angle values of Examples 1 to 6 in Table 1, the water contact angle values are significantly different even though both have almost the same chemical composition. This is true for Examples 1 to 6.
This confirms that the organic thin film obtained in the above has a unique molecular orientation.

【table】

[Table] Example 7 1 g of potassium polystyrene sulfonate in 100 ml
of water, and 5 ml of it was added to the water tank section (water temperature: 10°C) of Langmiur membrane manufacturing equipment. linear organic compound 8 mg was dissolved in 5 ml of a mixed solvent of ethanol/benzene (1/9 volume ratio), and 40 µ of the solution was spread on the water surface and left for 10 minutes to evaporate the ethanol/benzene. After that, while applying pressure from the side with a movable float and keeping the surface pressure at 30 dyn/cm, a 0.5 mm thick platinum plate was immersed 5 times at a speed of 0.3 mm/sec from a direction perpendicular to the water interface. perform the raising,
An organic thin film was formed on the porous membrane. As a result of analyzing the obtained organic thin film by ESCA, the N/S (atomic ratio) was 2.02. Also, the water contact angle is 117.0°
It was hot. Furthermore, after the obtained organic thin film was left at 60° C. for 1 hour, the water contact angle was further measured and found to be 116.8°, with almost no change observed. Example 8 1 g of potassium polyvinyl sulfonate was dissolved in 100 ml of water, and 5 ml of the solution was added to the water tank (water temperature: 20° C.) of a Langmiur membrane manufacturing apparatus. linear organic compound 10 mg was dissolved in 10 ml of a mixed solvent of ethanol/benzene (1/9 volume ratio), and 60 µ of the solution was spread on the water surface and left for 10 minutes to evaporate the ethanol/benzene. Then, while applying pressure from the side with a movable float and keeping the surface pressure at 35 dyn/cm, a 1 mm thick slide glass was immersed and pulled up from the direction perpendicular to the water interface at a speed of 0.5 mm/sec 10 times. An organic thin film was formed on a glass slide. As a result of analyzing the obtained organic thin film by ESCA, the N atoms/S atoms (atomic ratio) was 0.98. The water contact angle with respect to the obtained organic thin film was 105.1°. Further, the obtained organic thin film was heat-treated in air at 100°C for 1 hour, and the water contact angle measured was 103.6°, with almost no change observed. Example 9 1.0 g of carboxymethyl cellulose was dissolved in 100 ml of water, and 5 ml of the solution was added to the water tank (water temperature: 31.5° C.) of a Langmiur membrane manufacturing apparatus. linear organic compound 10mg of ethanol/benzene (1/9 volume ratio)10
ml, and 40μ of it was spread on the water surface and left for 5 minutes to evaporate the ethanol/benzene. Then, while applying pressure from the side with a movable float and maintaining a surface pressure of 32 dyn/cm, a 100 μm thick polystyrene film was immersed and pulled out at a speed of 1 mm/min 20 times from an angle of 20 degrees to the water surface. An organic thin film was formed on a polystyrene film. The water contact angle of the obtained organic thin film was 100.1°, and the water contact angle measured after standing in water at 60°C for 1 hour was 100.6°, with almost no change observed. Example 10 0.8 g of sodium polyacrylate was dissolved in 100 ml of water, and 5 ml of the solution was added to the water tank (water temperature: 20° C.) of a Langmiur membrane manufacturing apparatus. linear organic compound 8mg of ethanol/benzene (1/9 volume ratio)10
ml, and 50μ of the solution was spread on the water surface and left for 5 minutes to evaporate the ethanol/benzene. After that, 0.5mm from the perpendicular direction to the water surface.
Thick metal silicon substrate 30 times at a speed of 0.5 mm/sec.
It was immersed and pulled up. The water contact angle for the organic thin film formed on the metal silicon substrate was 97.0°. Furthermore, the water contact angle measured after heat-treating the organic thin film at 100° C. for 1 hour was 96.3°, with almost no change observed. Example 11 50 ml of 0.8 g of poly-4-vinylpyridine hydrochloride
of water, and 5 ml of it was added to the water tank section (water temperature: 15°C) of Langmiur membrane manufacturing equipment. linear organic compound 5mg of ethanol/benzene (2/8 volume ratio)5
ml, spread 50μ of it on the water surface, leave it for 5 minutes to evaporate the ethanol/benzene, and then apply a 0.5mm thick platinum plate from the direction perpendicular to the water surface at a speed of 0.3mm/sec for 10 minutes. It was immersed and pulled up twice. The contact angle of water to the organic thin film formed on the platinum plate was 99.6°. Furthermore, after immersing the organic thin film in water at 60° C. for 1 hour, the water contact angle was measured again and found to be 99.6°, with no change observed at all.

Claims (1)

[Scope of Claims] 1 () an organic compound having one straight chain hydrophobic group containing two or three straight chain hydrophobic groups or a rigid moiety in the chain, and having an ionic group; )
An aqueous solution containing a polymer having an ionic group having an opposite charge to the ionic group of the organic compound in () above is present to form an interface, and the substrate is placed in a direction perpendicular to or at an angle to the interface. A method for producing an organic thin film, which comprises immersing it in the aqueous solution and pulling it up to form an organic thin film on a substrate. 2. The method for producing an organic thin film according to claim 1, wherein the substrate is immersed and pulled up while applying horizontal pressure to the interface. 3. The method for producing an organic thin film according to claim 2, wherein the surface pressure at the interface is 10 dyn/cm to 50 dyn/cm.