JPH0611419B2 - Film forming method - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for forming a polymer compound film, and more particularly to a method for forming a modified polymer compound film by the Langmuir-Blodgett method. Is.

Conventional technology In the 1930s, it was found by Langmuir-Blodgett that fatty acids having about 16 to 22 carbon atoms could form a monomolecular film on the surface of water and accumulate it as a substrate. It has only recently started.

For an overview of previous research, see Solid State Physics 17 (12) 45 (1
982) Thin Solid Films 68 No.1 (1980), ibid, 99 No.1.2.
3 (1983) Insoluble monolayers at liquid-gas interfac
es (GLGains, Interscience Publishers, New York, 196
As described in 6), the conventional straight chain saturated fatty acid Langmuir-Blodgett film (hereinafter referred to as “LB film”) has defects in heat resistance and mechanical strength, and cannot be used as it is for practical applications. There is a problem.

To improve these, unsaturated fatty acids such as ω-
Unsaturated esters of tricosenoic acid, ω-peptadecenoic acid, α-octadecyl acrylic acid and fatty acids, such as vinyl stearate and octadecyl acrylate, as well as polymer films of diacetylene derivatives have been studied, but heat resistance is not sufficient. No, it cannot be said that it is electrically superior. Polymers with hydrophilic groups such as polyacids, polyalcohols, ethyl acrylates, and polypeptides are known to have film-forming properties, but they have been modified as materials for Langmuir-Blodgett films. Polymers have not been studied so far, and there is no excellent LB film material.

On the other hand, polyimide is used as a heat-resistant film, but it is very difficult to form a heat-resistant thin film of 1000 Å or more and usually 1 μm or more and 1000 Å or less without pinholes by a method such as spin coating.

Problems to be Solved by the Invention The present invention is to enable film formation by the same method by modifying a polymer compound that is originally difficult to form by the Langmuir-Blodgett method. It is an object of the present invention to provide a polymer thin film having improved mechanical properties such as chemical resistance and adhesive strength, which is generally difficult to form into a film.

Means for Solving the Problems In order to impart hydrophobicity to a repeating unit of a polymer compound, a substituent having 1 to 9 carbon atoms, preferably 4 to 9 carbon atoms is introduced, and this modified polymer compound and known compounds are known. It is made by mixing with a Langmuir film compound to form a film by the Langmuir-Blodgett method.

Detailed Discussion One of the LB film materials used in the present invention is at least a divalent first organic group R ₁ having at least two carbon atoms and an at least divalent first organic group R ₁ having at least two carbon atoms. 10 carbon atoms, which may have a substituent group, having linear repeating units in which the two organic groups R ₂ are alternately linked by a divalent linking group, and which are bound to the same repeating unit by a covalent bond Polymer compounds containing at least one hydrocarbon-containing group R ₃ of ˜30.

More specifically, the polymer compound of the present invention has a linear repeating unit serving as a basic skeleton. Composed of.

Here, R ₁ is at least a divalent first organic group containing at least 2 carbon atoms, and R ₂ is an at least divalent second organic group containing at least 2 carbon atoms. More preferably, one or both of R ₁ and R ₂ is a group characterized by benzenoid unsaturation having at least 6 carbon atoms.

AB and BA in the formulas (1) to (3) are divalent linking groups formed by the reaction between the acidic group A containing a hetero atom such as O, N, S, P and B and the basic group B. More specifically, −COOR,
(R is an alkyl group or a hydrogen atom, the same applies hereinafter) -COX,
(X is Cl or Br, the same applies hereinafter) -NCO, -NCS, -CN,-
A group formed by the reaction of an acidic group A such as CONHR with a basic group B such as -NHR, -OR, -SR, -X, where AB is And BA is Etc.

The polymer compound of the present invention has 1 to 9 carbon atoms which may have a substituent covalently bonded to the same repeating unit of the basic skeleton of (1) to (3), preferably 4 to 9 carbon atoms. Modified to contain at least one, and preferably two, of the hydrocarbon-containing groups R ₃ of.

There are three possible methods for realizing such modification.

[I] A method of substituting R ₃ for an atom contained in the groups AB and BA in the linear repeating units of the formulas (1) to (3).

[II] A method of directly substituting R ₃ for R ₁ and R ₂ , and further, [III] R ₁ and R ₂ other than those used to make linear repeating units of R ₁ and R ₂ . It is a method of substituting R ₃ through a substituent.

Of course, it may be possible to use [I], [II], and [III] together. When R ₃ is 2 or more, they may be the same or different.

Specific examples of [I], [II], and [III] are as follows.
[I] is Instead of the hydrogen atom on the nitrogen atom of AB and BA as shown in the table above
This is a method of replacing R ₃ .

The method of [II] is a method of directly substituting R ₃ for R ₁ and R ₂ , Are some of the examples.

The method with more possibilities is that of [III]. This will be described in detail.

The method [III] is a method in which at least one of R ₁ and R ₂ is at least a trivalent organic group, and R ₁ and R ₂ are substituted through a substituent other than those used to form the repeating unit containing R ₁ and R _{2. 3}
In the method of replacing the, but not of course limited thereto, or R ₁ is R ₂ and valence are equal, the valence case often illustrate to 6, the valence R ₂ of R ₁ valence The numbers 3 2 4 2 5 2 6 2 3 3 4 3 5 3 6 6 3 4 4 5 4 6 4 5 5 6 5 6 6 6.

Although examples in which R ₁ and R ₂ have a valence of 5 or more are also listed here, it is particularly preferable that R ₁ and R ₂ have a valence of 4 or more.

R ₁ = 3, R ₂ = divalent R ₁ = 4, R ₂ = trivalent R ₁ = 4, R ₂ = 2 R ₁ = 4, R ₂ = 4 R ₁ = 3, R ₂ = 3 To give a concrete example, when R ₁ = 3 and R ₂ , When R ₁ = 4 and R ₂ = 2, When R ₁ = 3 and R ₂ = 3, When R ₁ = 4 and R ₂ = 3, When R ₁ = 4 and R ₂ = 4, Is. In formulas (4) to (75), A / B which is not used to form a linear repeating unit exists, but the method [III] is a method of substituting R ₃ through this substituent. For example, if (4) to (75) is A, -COOR ₃ , -CONHR ₃ , -NHCOOR ₃ ,
If -NHCSOR ₃ etc., B can be replaced by -NHR ₃ , -OR ₃ , -SR ₃ etc.

R ¹ and R ² in the general formula are tetravalent groups containing at least 2 carbon atoms, preferably 5 to 20 carbon atoms, and may be aromatic groups, cyclic It may be an aliphatic group, or may be a group in which an aromatic group and an aliphatic group are bonded, and further, these groups may be an aliphatic group having 1 to 30 carbon atoms or a cycloaliphatic group. Group or a group in which an aromatic group and an aliphatic group are bonded, and those groups are a halogen atom, a nitro group, an amino group, a cyano group, a methoxy group,
A monovalent group such as an acetoxy group, or the monovalent group
-O-, -COO-, -NHCO-, -CO-, -S-, -CSS-, -NHCS-, -CS-
It may be a group which is substituted with a group bonded to the group to become a derivative. However, when R ¹ and R ² are groups characterized by benzenoid unsaturation having at least 6 carbon atoms, they are preferable in terms of heat resistance, chemical resistance, mechanical properties, and the like.

The benzenoid unsaturation referred to in the present specification is a term used in comparison with a quinoid structure with respect to the structure of a carbocyclic compound, and refers to a structure having the same shape as the carbocycle contained in a common aromatic compound.

The following is a suitable example for describing R ₁ and R _{2 in} more detail.

Where R ₄ is-(CH ₂ ) p-p = 1-3, -O -, - CO -, - S-, -SO 2 -, R ₅ : alkyl or aryl group _{- (CH 2) q- (q} = 2~10), − (CH ₂ ) ₁₀ CH−CH ₃ , -(CH ₂ ) ₃ -0- (CH ₂ ) ₂ -0- (CH ₂ ) _3- , (R ₄ is the same as above) (R ₄ is the same as above) From the above, more preferable examples of R ₁ and R ₂ will be given. (R ₄ is the same as above). Bonds of R ^1, R ² is when present two carbon atoms adjacent constituting R ^1, R ² generates a 5- or 6-membered ring containing a hetero ring in the example above Easy and desirable.

R ₃ is a hydrocarbon-containing group having 1 to 9 carbon atoms, preferably 4 to 9 carbon atoms, which is selected from aliphatic, cycloaliphatic and aliphatic, aromatic and aliphatic bonds, and substituted products thereof. Valuable groups are preferred specific examples and are listed by (CH ₃ ) (CH ₂ ) n _-1 , Here, n = 1 to 9, preferably 4 to 9 and the like, and a linear aliphatic monovalent hydrogen group is a particularly preferable example.

Substituents for these include a halogen atom, a nitro group, an amino group, a cyan group, a methoxy group and an acetoxy group, but they are not essential. However, since the fluorine atom improves the hydrophobicity over the hydrogen atom, it is desirable to use it in some cases.

Further, when R ³ contains a dimerizable or polymerizable unsaturated bond, hydrophobicity can be imparted at the same time, which is preferable. As such a specific example, for example, CH ₂ ═CH (CH ₂ ) _n CH ₃ ═CH (CH ₂ ) _l C≡C—C≡C (CH ₂ ) m l + m = n−1 (N is 1 to 9, preferably 4 to 9) and the like. In these specific examples, the dimerizable or polymerizable portion is a highly hydrophilic portion, so the carbon number of this portion is not included in n.

Specific examples of the polymer compound applicable to the film forming method of the present invention include specific examples of R ₁ , R ₂ , R ₃ , A, B, AB and BA in formulas (1) to (75) and R ₃ It becomes clear by substituting each specific example of the method of substituting. Copolymers are not included in (1) to (75), but copolymers inferred from these are of course included in the present invention.

The molecular weight of the polymer compound of the present invention is not particularly limited. However, even if the molecular weight is low, film formation is possible by the film formation method of the present invention, but good heat resistance, mechanical strength, and chemical resistance cannot be obtained. On the other hand, if the molecular weight is too high, the viscosity will be too high and film formation will not be successful.

Therefore, those having a number average molecular weight of about 2,000 to 300,000 are desirable.

The practical specific examples of the polymer compound of the present invention derived from the formulas (1) to (75) are as follows.

In the formula, → represents isomerism.

For example, if the following equation (78) is used, and Represents

In the present invention, when (78-1) (78-2) is alone (78-1) (78-
Including the case where 2) coexists.

Other examples are, for example, Hirotaro Kobe, heat resistance of polymers (Baifukan, S45.3.5), thermal decomposition and heat resistance of polymers (Baifukan, S4).
9.3.15) etc. can be requested.

In order to explain the method for producing these modified polymer compounds, the case of R ₃ ═CH ₃ (CH ₂ ) ₇ − in formula (80) is described. Obtained by alcoholysis of pyromellitic dianhydride At a temperature of -2 in an organic polar solvent under substantially anhydrous conditions.
It is produced by acylating with thionyl chloride at 0 ° C or higher and reacting it with diaminodiphenyl ether at a temperature of -20 ° C or higher. The acylation and amidation reactions are usually carried out at 0 ° C. or lower and about −10 ° C., but in the present invention, since the alkyl group has a carbon length of 1 to 9, it may be carried out under ordinary conditions without particular limitation. You can

Of course, in the above case, a raw material having different substituents is mixed to form a copolymer, or 0 to 30% of substituents are absent.
You may mix with tetracarboxylic dianhydride and diamine.

The amphoteric polyimide precursor produced as described above may be separated and purified as a Langmuir-Blodgett film material, or after production, chloroform, benzene or the like may be added directly to obtain a Langmuir-Blodgett film developing solution.

Next, a method for producing the Langmuir-Blodgett film used in the present invention will be described.

The Langmuir-Blodgett film is produced by spreading the substance forming the film on the water surface, compressing the substance spread on the water surface at a constant surface pressure to form a monomolecular film, and then placing the film on the substrate. In addition to the transfer method, the horizontal attachment method, the rotating cylinder method and the like (New Experimental Chemistry Course, Volume 18, Interfaces and Colloids, 498-508) and the like can be mentioned. It can be used without limitation.

The Langmuir-Blodgett method is an excellent method for forming a thin film of 200 Å or less, further 1000 Å or less, hundreds of Å, tens of Å by a method in which the thickness can be controlled in units of several tens of Å. The thin film on the substrate also has this feature. However, films with a thickness of 10,000Å or more can also be formed by this method.

The present invention has found that the modified polymer compound of the present invention can be formed into a film by mixing it with a known Langmuir-Blodgett film compound, and has reached the present invention.

The known Langmuir-Blodgett film compound is a compound described in the documents cited above and known in the art. Particularly preferred is a compound of the following formula, which comprises a hydrocarbon group having 16 to 22 carbon atoms and a hydrophilic group.

The mixing ratio is not particularly limited, but the more the known LB film compound is used, the better the film forming performance, which is desirable.
An equimolar to 5-fold molar amount is preferably used.

CH ₃ (CH ₂ ) _n-1 Z CH ₂ = CH (CH ₂ ) _n-2 Z CH≡C- (CH ₂ ) _n-2 Z CH ₃ (CH ₂ ) _l C≡C C≡C (CH ₂ ) mZ where n = 16 to 22, l + m = n-5, Z = OH, NH
₂ , NHR ', NR'R', COOH, CONH ₂ , CONHR ', CONR'R', COO
R '(R' is a lower aliphatic hydrocarbon) Although not a known Langmuir-Blodgett film compound, the following compounds are also suitable for the present invention.

Etc.

In order to improve the film forming property, the _one represented by the formula of CH ₃ (CH ₂ ) _n-1 Z is superior in terms of cost, but those containing unsaturated bonds should be irradiated with light or radiation. It has a feature that can be polymerized by.

The mixing ratio of at least one compound selected from these and the polymer compound is not particularly limited. At least two selected from the polymer compounds of the present invention may be used for film formation.

When a film-forming component is spread on the water surface by the Langmuir-Blodgett method, benzene, chloroform, etc., which do not dissolve in water but evaporate in the gas phase, are generally used as the solvent. For high-molecular compounds,
It is desirable to use an organic polar solvent in combination to increase the solubility. Preferred organic polar solvents are N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, N-methyl-2. -Pyrrolidone, pyridine, dimethyl sulfone, hexamethylphosphoramide, tetramethylene sulfone, dimethyl tetramethylene sulfone and the like.

Therefore, the polymer of the present invention and known Langmuir
It is desirable to use a mixed solvent of a solvent such as benzene and chloroform and an organic polar solvent also when developing the compound of the blow jet film.

When benzene, chloroform, etc. are used in combination with an organic polar solvent, it is considered that benzene, chloroform, etc. evaporate in the gas phase when the film is developed, and the organic polar solvent is dissolved in a large amount of water.

The substrate used in the present invention is limited depending on what the thin film of the present invention is applied to, but is not particularly limited, and is a general inorganic substrate such as glass, alumina, and quartz. In addition to metals, plastics, semiconductors such as IV, III-V and II-VI groups such as Si, GaAs and ZnS, ferroelectrics and magnetic substances such as PbTiO ₃ , BaTiO ₃ , LiNbO ₃ and LiTaO _3. Etc. can also be used as the substrate. Further, it is of course possible to use a product which has been subjected to a surface treatment which is usually carried out.

Of course, the metal thin film on the substrate as described above may be patterned so as to be suitable for the application, or a semiconductor such as Si, GaAs, ZnS or a substrate made of a ferroelectric substance may be processed in advance to obtain a device. May be formed. Further, it is of course possible to use a product which has been subjected to a surface treatment which is usually carried out.

In the case of the polyimide precursor of the present invention, glass, quartz,
Adhesive strength tends to be weak on the surface of Si, SiO ₂ etc., and silane coupling agents, especially silane coupling agents having amino groups or epoxy groups and alkoxy groups (eg UCC
-1100, A-187, etc.) or a chelate containing aluminum metal to form an aluminum oxide layer improves the film forming characteristics and adhesive strength, and is a preferred embodiment of the present invention. Of course, the substrate may be treated with several layers of higher fatty acid metal as is done in the art.

A feature of the present invention is that a polymer compound having good heat resistance can be formed into a thin film on a substrate by the Langmuir-Blodgett method, but another one is that the thin film is partially or completely closed. The feature is that a thin film with further improved heat resistance can be formed on the substrate.

Of the examples of (76) to (95), (78) to (90) include a hetero atom 5
This is an example in which the ring can be partially or completely closed to a member ring or a 6-membered ring, and the structure after complete ring closure is as follows.

The method of ring closure is not particularly limited.
In the case of imidization, which is a variant of formula (80), it is 300 to 40.
By heating to a temperature near 0 ° C, the polymer compound of formula (80) And the ring closure is achieved. At this time, the group introduced for hydrophobization is eliminated as alcohol, and the eliminated alcohol having 1 to 9 carbon atoms is 300 to 40 ° C.
It can be easily scattered by placing it under a gas flow or under a vacuum at a temperature near 0 ° C. if necessary, so that a polyimide thin film having very good heat resistance can be obtained.

Further, since the carbon number is 1 to 9, it is preferable because the weight reduced by imidization is small.

When a thin film having good heat resistance is obtained by ring-closing in this way, as the known Langmuir-Blodgett film compound to be mixed, one that can be scattered under the ring-closing reaction condition is selected from the examples given above. Is desirable.

Next, applications of these thin films will be described.

INDUSTRIAL APPLICABILITY The thin film of the present invention has excellent heat resistance, chemical resistance, and mechanical properties, and can be used in a wide range of fields such as the electronics field, energy conversion, and substance separation by taking advantage of the fact that it is a very thin film.

Optical recording film, resist film, insulating film, thin film for capacitors, liquid crystal alignment film, in the electronics field that takes advantage of conductivity, photoconductivity, optical properties, insulation properties, thermal properties and chemical reactivity.
As a polarizing film, a sensor film, etc., especially as an insulating film,
It can be used as an insulating layer of C and LSI, and it can be used as an insulating layer in electric and electronic devices having a structure such as MIS and MIM combined with various semiconductors and metals, and it can be used as an insulating layer in field effect transistors, photoelectric conversion elements, light emitting elements, light receiving elements, and light detection. Devices, thermionic transistors, etc. can be configured. In particular, the thin film of the present invention is effective for MIS and MIM devices utilizing the tunnel effect.
It can also be used as an insulating film for J.

In addition, it can be applied as a clad material for a wave guide or an optical circuit component.

It may be suitable as a protective coating material in all fields, and the method of a mixed film or a laminated film of a functional LB material and a fatty acid generally used in the field of an LB film is used instead of the mixture of the present invention for the fatty acid. Various functionalities can be expressed by using it, and the application using this can be considered. For example, a photoelectric conversion element or a biosensor can be manufactured by forming a film containing a dye and oxygen.

In addition, applications in the field of substance separation using this thin film are also conceivable.

Next, a method for producing a polymer compound and a method for forming a film of the present invention will be described based on examples.

Example 1 10.91 g of pyromellitic dianhydride and 26.0 g of octyl alcohol were reacted at 120 ° C. for 3 hours, the crude product was washed with ethanol to remove unreacted octyl alcohol, and then recrystallized with 200 ml of ethanol. Dioctyl pyromellitate was obtained.

2.39 g of this dioctylpyromellitate was dissolved in 60 cc of hexamethylenephosphamide, cooled to 5 ° C., thionyl chloride 1.19 was added dropwise at about 5 ° C., and the mixture was kept for about 1 hour after the addition to complete the reaction. Let After that, 1.0 g of diaminodiphenyl ether dissolved in 30 cc of dimethylacetamide was added dropwise at about 10 ° C., the reaction temperature was raised to about 20 ° C., the reaction was performed for 2 hours, and then poured into 400 cc of ethanol to precipitate a reaction product. . The precipitate was filtered and dried at 40 ° C. to obtain about 2.9 g of a pale yellow powder.

IR spectrum analysis, thermal analysis (TGA-DTA), and molecular weight measurement by GPC gave the following results.

IR spectrum analysis The IR chart obtained by the KBr disc method showed characteristic absorptions of ester, amide I, II, III, alkyl chain and ether.

Thermal analysis (TGA-DTA) RTG-DTA (H) type full-scale TGA10 manufactured by Rigaku Denki
mg, DAT 100μV, temperature rises at 1000 ℃ 10 ℃ / mi
Figure 2 shows the results measured in a nitrogen stream (30 m / min).
It is as follows. 192,270,318,3 in TGA
Although there is an inflection point at 95,580 ° C, DTA has no characteristic peak.

Molecular weight measurement by GPC Chloroform, N, N-dimethylacetamide (8: 2)
The number average molecular weight measured with the mixed solvent was about 25,000 in terms of polystyrene.

Example 2 55.1 mg of the product of Example 1 distilled chloroform /
It was dissolved in a mixed solution of dimethylacetamide = 8/2 (volume ratio) to prepare 25 ml of a developing solution for LB membrane.

When the relationship between the surface pressure and the area per repeating unit was measured at 20 ° C. on redistilled water, a liquid expanded film was obtained and a good condensed film was not formed.

A solution of stearyl alcohol having the same molar concentration as the above solution was mixed in the same volume, and the surface pressure area curve was evaluated so that the number of repeating units of the product of Example 1 and the total number of molecules of stearyl alcohol were equal. However, the curve rose considerably and a condensed film was obtained. It was also revealed that the condensed film was further stabilized as the number of molecules of stearyl alcohol increased with respect to the number of repeating units of the product of Example 1.

The accumulation on the glass substrate on which aluminum was vapor-deposited was Y-type regardless of addition of stearyl alcohol, and a good accumulated film was obtained.

Furthermore, the product of Example 1 and stearyl alcohol 1:
1 (molar ratio) of the mixture is accumulated on the germanium substrate,
FT-AT when heated at 400 ° C under nitrogen flow for 1 hour
Disappearance of stearyl group and 1790,17 by R-IR method
The appearance of a 10-cm ⁻¹ 5-membered ring imide was observed.

Example 3 In the same manner as in Example 2, stearic acid, ω-heptadecenoic acid, and octadecane were used in place of stearyl alcohol, and the surface pressure area curve was evaluated. It was found that the rising speed became steep and the collapse pressure also increased.

The disintegration pressures of stearic acid and ω-heptadecenoic acid were almost the same as those of stearyl alcohol, and were superior to those of octadecane.

The film to which stearic acid, ω-heptadecenoic acid, and octadecane had been added was accumulated in Y-type on the glass substrate on which aluminum was vapor-deposited, and a good accumulated film was obtained.

EFFECTS OF THE INVENTION According to the present invention, a polymer compound modified so that it can be formed into a film by the LB film method can form a more stable film on the water surface together with a known LB film material, and can be well accumulated on the substrate. Become. Further, by partially or completely cyclizing, a known LB film compound mixed at the same time is scattered, resulting in extremely good heat resistance, good chemical resistance, and good mechanical properties. , Ie 1
Ultra-thin films of 10,000 Å or less, or 10 to 1000 Å can be obtained if desired.

Claims (10)

[Claims] 1. A divalent first organic group R ₁ having at least two carbon atoms and a divalent second organic group R ₂ having at least two carbon atoms are divalent. Hydrocarbons having linear repeating units alternately linked by a linking group, and optionally having a substituent, which are bonded to the same repeating unit by a covalent bond, and have 1 to 9 carbon atoms, preferably 4 to 9 carbon atoms. A film-forming method comprising forming a mixture of a polymer compound containing at least one containing group R ₃ and a known Langmuir-Blodgett film compound into a cumulative film by the Langmuir-Blodgett method. 2. The film forming method according to claim 1, which contains two hydrocarbon-containing groups R ₃ per repeating unit. 3. The film forming method according to claim 1, wherein one or both of the first and second organic groups R ₁ and R ₂ is a benzenoid group having at least 6 carbons. 4. A hydrocarbon-containing group R ₃ containing an aliphatic group, a cycloaliphatic-aliphatic bonded group, an aromatic-aliphatic bonded group, or a substitution product thereof. The film forming method according to item 1 or 2. 5. The film forming method according to claim 1 or 2, which is a polymer compound containing at least one dimerizable or polymerizable unsaturated bond in the molecule. 6. The film forming method according to any one of claims 1 to 4, wherein the repeating unit has a precursor structure which produces a 5-membered ring or a 6-membered ring containing a hetero atom. 7. The film forming method according to claim 5, which includes a step of heating a cumulative film to generate a 5-membered ring or a 6-membered ring containing a hetero atom. 8. The hydrocarbon-containing group R ₃ has 16 to 2 carbon atoms.
2. The film forming method according to any one of 1 to 6, which is 2. 9. The film-forming method according to any one of claims 1 to 7, wherein the known Langmuir-Blodgett film compound is a compound having a hydrocarbon group having 16 to 22 carbon atoms and a hydrophilic group. 10. A known Langmuir-Blodgett film compound, which is a compound comprising a hydrocarbon group having 16 to 22 carbon atoms and a hydrophilic group and containing a dimerizable or polymerizable unsaturated bond. Film forming method.