JPWO2015146103A1 - Organic thin film forming solution and organic thin film forming method using the same - Google Patents

Abstract

It is an object of the present invention to provide a method capable of producing a dense, colorless and transparent organic thin film that can be formed quickly and contains few impurities without complicated management. Formula (I) R1nMXm-n (I) (In the formula (I), R1 has an aliphatic hydrocarbon group having 14 to 30 carbon atoms, a substituent or a linking group which may have a substituent or a linking group. Represents an optionally halogenated aliphatic hydrocarbon group having 14 to 30 carbon atoms, and M is at least one metal selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom. Represents an atom, X represents a hydroxyl group or a —NR22 group, at least two of X represent a —NR22 group, and R2 represents a hydrogen atom and a C 1-10 which may have a substituent. Represents an alkyl group or a phenyl group which may have a substituent, R2 may be the same or different, and m represents a valence of M. n is from 1 to (m−2 ) Represents any positive integer, and n is 2 or more , R1 forms an organic thin film using an organic thin film forming solution containing an organic metal compound represented by may be the same or different.).

Description

The present invention relates to the formation of an organic thin film, and particularly relates to an organometallic compound suitable for forming an organic thin film on a substrate surface, an organic thin film forming solution containing the same, and an organic thin film forming method using them.
This application claims priority with respect to the Japan patent application 2014-64035 for which it applied on March 26, 2014, and uses the content here.

Conventionally, the surface of a substrate made of glass, metal, plastics, ceramics or the like is modified in various fields according to the purpose.
For example, a method for producing an organic thin film such as a monomolecular film using a metal surfactant represented by the following formula is known. (Patent Documents 1 to 5)
R _n MX _m−n
(In the formula, R represents a hydrocarbon group having 10 to 30 carbon atoms which may have a substituent, a halogenated hydrocarbon group having 10 to 30 carbon atoms which may have a substituent, and a linking group. Represents a halogenated hydrocarbon group containing a hydrocarbon group or a linking group, M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom and a zirconium atom, Represents a hydroxyl group or a hydrolyzable group, m represents the valence of M. n represents a positive integer from 1 to (m−1), and when n is 2 or more, R may be the same or different. Well, when (mn) is 2 or more, Xs may be the same or different.
On the other hand, Non-Patent Document 1 describes that when a silicon wafer is immersed in a toluene solution of (N, N-dimethylamino) -octadecyldimethylsilane, a covalent monomolecular film can be formed on the surface.

International Publication 2003-077604 Pamphlet International Publication No. 2004-091810 Pamphlet International Publication No. 2006-009202 Pamphlet International Publication No. 2008-059840 Pamphlet International Publication No. 2009-104424 Pamphlet

Displacement Reactions of Covalently Attached Organosilicon Monolayers on Si Langmuir, 2006, 22, 8271-8272

In Patent Documents 1 to 5, it is necessary to use a hydrolysis catalyst in order to produce a high-speed and dense crystalline monomolecular film, and complicated control such as strictly controlling the amount of water in the organic thin film forming solution. Necessitating proper composition control.
In the above formula, as the hydrolyzable group, an alkoxy group having 1 to 6 carbon atoms which may have a substituent, an acyloxy group which may have a substituent, a fluorine atom, a chlorine atom, a bromine atom, iodine Illustrative are halogen atoms such as atoms, isocyanate groups, cyano groups, amino groups, or amide groups. However, only the alkoxy group is actually used, and there is no specific example or description about the use of the amino group.
Non-Patent Document 1 describes that a monomolecular film can be obtained by an immersion method without using a hydrolysis catalyst. However, it takes 3 days to form the film, and the film thickness is thin and the hydrophobicity is low. Thus, it is difficult to say that the formed film is a dense film.
The present invention has been made in view of the circumstances of the prior art, and an object of the present invention is to provide a method for forming a colorless, transparent, and dense organic thin film easily and quickly.

  As a result of diligent research to solve the above problems, the present inventors have used a substituted or unsubstituted amino group as a hydrolyzable group of an organometallic compound, so that a dense organic compound can be obtained in a short time without using a hydrolysis catalyst. The present inventors have found that a thin film can be formed and that complicated composition management of a solution for forming an organic thin film is unnecessary, and the present invention has been completed.

That is, the present invention
(1) Formula (I)
R ¹ _n MX _mn (I)
(In the formula (I),
R ¹ is an aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group, and a halogenated aliphatic carbon atom having 14 to 30 carbon atoms which may have a substituent or a linking group. Represents a hydrogen group,
M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom;
X represents a hydroxyl group or a —NR ² ₂ group, at least two of X represent a —NR ² ₂ group, and R ² represents a hydrogen atom and a carbon number of 1 to 10 which may have a substituent. An alkyl group or a phenyl group which may have a substituent, R ² may be the same or different, and m represents the valence of M.
n represents any positive integer from 1 to (m−2), and when n is 2 or more, R ¹ may be the same or different. )
An organometallic compound represented by
(2) The organometallic compound according to (1), wherein the organometallic compound represented by the formula (I) is tris (N, N-dimethylamino) octadecylsilane,
(3) The organic thin film forming solution containing the organometallic compound according to (1) or (2), and (4) the organic thin film forming solution according to (3), wherein the organic thin film is a monomolecular film.

further,
(5) Formula (I)
R ¹ _n MX _mn (I)
(In the formula (I),
R ¹ is an aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group, and a halogenated aliphatic carbon atom having 14 to 30 carbon atoms which may have a substituent or a linking group. Represents a hydrogen group,
M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom;
X represents a hydroxyl group or a —NR ² ₂ group, at least two of X represent a —NR ² ₂ group, and R ² represents a hydrogen atom and a carbon number of 1 to 10 which may have a substituent. An alkyl group or a phenyl group which may have a substituent, R ² may be the same or different, and m represents the valence of M.
n represents any positive integer from 1 to (m−2), and when n is 2 or more, R ¹ may be the same or different. )
An organic thin film forming method for forming an organic thin film on the surface of the substrate by bringing a solution for forming an organic thin film containing the organometallic compound represented by the formula into contact with the substrate, and (6) the organic thin film is a monomolecular film It is related with the organic thin film formation method as described in (5).

  According to the present invention, an organic thin film having dense crystallinity can be formed in a short time without using a hydrolysis catalyst. Moreover, since complicated composition management of the solution for forming an organic thin film is unnecessary, the solution can be easily prepared.

It is a figure which shows the measurement result of the film thickness by the X ray diffraction of the organic thin film of Example 1. FIG. It is a figure which shows the measurement result of the crystallinity by the X ray diffraction of the organic thin film of Example 1. FIG. It is a figure which shows the measurement result of the crystallinity by the X-ray diffraction of the organic thin film of the comparative example 1. It is a figure which shows the measurement result of the crystallinity by the X-ray diffraction of the organic thin film of the comparative example 2.

1. Organometallic compounds
The organometallic compound of the present invention has the formula (I)
R ¹ _n MX _mn (I)
It is a compound represented by these.
In the above formula (I), R ¹ may have a substituent or a linking group, and may have an aliphatic hydrocarbon group having 14 to 30 carbon atoms, a substituent or a linking group. 30 represents a halogenated aliphatic hydrocarbon group, M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom, and X represents a hydroxyl group or represents -NR ² ₂ group, at least two of X represents a ^-NR _{2 2} group, ^{R 2} is a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or Represents a phenyl group which may have a substituent, R ² may be the same or different, and m represents the valence of M. n represents any positive integer from 1 to (m−2), and when n is 2 or more, R ¹ may be the same or different.
(Mn) is 2 or more, and X may be the same or different. Below, each substituent is demonstrated.

The “—NR ² ₂ group” of X is an amino group, an alkyl group having 1 to 10 carbon atoms which may have 1 or 2 substituents, or a phenyl group which may have substituents. It means a substituted amino group.
Among the above, the mono-substituted amino group includes methylamino group, ethylamino group, n-propylamino group, isopropylamino group, n-butylamino group, isobutylamino group, t-butylamino group, and n-pentylamino group. And anilino group.

Among the above, examples of the di-substituted amino group include dimethylamino group, diethylamino group, di-n-propylamino group, diisopropylamino group, methylethylamino group, methyl n-propylamino group, methylphenylamino group, diphenylamino group, and the like. Is mentioned.
Examples of the substituent of the “optionally substituted alkyl group having 1 to 10 carbon atoms” and the “optionally substituted phenyl group” include a carboxyl group; an amide group; an imide group; an ester group Alkoxy groups such as methoxy group and ethoxy group; hydroxyl groups; halogen atoms and the like.

The “aliphatic hydrocarbon group having 14 to 30 carbon atoms” of the “aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group” of R ¹ has 14 to 30 carbon atoms. And an alkyl group having 14 to 30 carbon atoms and an alkynyl group having 14 to 30 carbon atoms. The alkyl group, alkenyl group and alkynyl group may be linear or branched.

Examples of the alkyl group having 14 to 30 carbon atoms include a tetradecyl group, a palmityl group, a stearyl group, an eicosanyl group, a docosanyl group, a tetracosanyl group, an octacosanyl group, and a triacontanyl group;
Examples of the alkenyl group having 14 to 30 carbon atoms include a tetradecenyl group, a palmitoleinyl group (9-hexadecenyl group), an oleinyl group (cis-9-octadecenyl group), a buccenyl group (11-octadecenyl group), and a linolyl group (cis). , Cis-9,12-octadecadienyl group), 9,12,15-linolenyl group (9,12,15-octadecanetrienyl group), 6,9,12-linolenyl group (9,12,15- Octadecanetrienyl group), eleostearinyl group (9,11,13-octadecatrienyl group), 8,11-eicosadienyl group, 5,8,11-eicosatrienyl group, arachidonyl group (5,8,11) , 13-eicosatetraenyl group), nerbonyl group (cis-15-tetracosaenyl group), docosahexaenyl group, Printer eicosapentaenoic enyl group or the like;
Examples of the alkynyl group having 14 to 30 carbon atoms include 8-tetradecynyl group, 8-pentadecynyl group, 8-hexadecynyl group, 8-heptadecynyl group, 8-octadecynyl group, 8-icosinyl group, 8-docosinyl group, heptadecyl-8, and the like. , 11-diynyl group and the like.

R ¹ preferably has 14 to 22 carbon atoms, and more preferably has 16 to 20 carbon atoms.

Examples of the “substituent” of the “aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group” of R ¹ include a carboxyl group; an amide group; an imide group; an ester group; , An alkoxy group such as an ethoxy group; or a hydroxyl group. The number of these substituents is preferably 0-3.

Specific examples of the “linking group” of “the aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group” for R ¹ include —O—, —S—, — SO ₂ —, —CO—, —C (═O) O— or —C (═O) NR ⁵¹ — (wherein R ⁵¹ represents a hydrogen atom; a methyl group, an ethyl group, an n-propyl group, an isopropyl group. An alkyl group such as; a phenyl group; a benzyl group, etc.). The position at which the linking group is inserted is not particularly limited, but is preferably present between the carbon-carbon bonds of the aliphatic hydrocarbon group.

The “halogenated aliphatic hydrocarbon group having 14 to 30 carbon atoms” of the “halogenated aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group” of the substituent R ¹ is: Examples include a group in which one or more hydrogen atoms in the aliphatic hydrocarbon group having 14 to 30 carbon atoms are substituted with a halogen atom.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, etc. are mentioned, A fluorine atom is preferable. More preferably, when two or more are fluorinated aliphatic hydrocarbon groups substituted with fluorine atoms and have a branched structure, the branched portion is a short chain having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms. Is preferred.

Among the fluorinated aliphatic hydrocarbon groups, a fluorinated alkyl group is preferable, a group in which one or more fluorine atoms are bonded to a terminal carbon atom is preferable, and a group in which three or more fluorine atoms are bonded to a terminal carbon atom is more preferable. . A carbon chain having an aliphatic hydrocarbon group that is not substituted with a fluorine atom at the end of the carbon chain and an aliphatic hydrocarbon group substituted with a fluorine atom inside the carbon chain may be used. The hydrogen atoms of all alkyl group at the end has a perfluoroalkyl group substituted by fluorine atoms, and, between the metal atom M to be described later to the perfluoroalkyl _{group, - (CH 2) h -} ( wherein H represents an integer of 1 to 6, preferably an integer of 2 to 4).

  The number of fluorine atoms in the fluorinated alkyl group is [(number of fluorine atoms in the fluorinated alkyl group) / (number of hydrogen atoms present in the alkyl group having the same carbon number corresponding to the fluorinated alkyl group) × 100]%. Is preferably 60% or more, and more preferably 80% or more.

The “substituent” and the “linking group” of the “halogenated aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group” of the substituent R ¹ are the above “substituent or linking group”. It is the same as the “substituent” and “linking group” of the “C14-C30 aliphatic hydrocarbon group which may have a group”. The position at which the linking group is inserted is not particularly limited, but it preferably exists between the carbon-carbon bonds of the halogenated aliphatic hydrocarbon group.

  M represents one kind of atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom. Among these, a silicon atom is particularly preferable from the viewpoints of availability of raw materials and reactivity.

  m is the valence of M, and n represents any positive integer from 1 to (m−2). In order to produce a dense organic thin film, n is preferably 1.

  Among the compounds represented by formula (I), specific examples in the case where n is 1 include those shown below. In the following, compounds in which the metal atom M is a silicon atom are shown as representative examples, but the present invention is not limited to these.

CH ₃ (CH ₂ ) ₁₃ Si [N (CH ₃ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₄ Si [N (CH ₃ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₅ Si [N (CH ₃ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₇ Si [N (CH ₃ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₂₅ Si [N (CH ₃ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₄ Si [N (C ₂ H ₅ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₇ Si [N (C ₂ H ₅ ) ₂ ] _{3
CH 3 (CH 2) 25 Si} [N (C 2 H 5) 2] 3
CH ₃ (CH ₂ ) ₁₄ Si [N (C ₆ H ₆ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₅ Si [N (C ₆ H ₆ ) ₂ ] ₃
CH ₃ (CH ₂ ) ₁₇ Si [N (C ₆ H ₆ ) ₂ ] _{3
CH 3 (CH 2) 25 Si} [N (C 6 H 6) 2] 3

CH ₃ (CH ₂ ) ₁₃ Si [NH (CH ₃ )] ₃
CH ₃ (CH ₂ ) ₁₄ Si [NH (CH ₃ )] ₃
CH ₃ (CH ₂ ) ₁₅ Si [NH (CH ₃ )] ₃
CH ₃ (CH ₂ ) ₁₇ Si [NH (CH ₃ )] ₃
CH ₃ (CH ₂ ) ₂₅ Si [NH (CH ₃ )] ₃
CH ₃ (CH ₂ ) ₁₄ Si [NH ₂ ] ₃
CH ₃ (CH ₂ ) ₁₅ Si [NH ₂ ] ₃
CH ₃ (CH ₂ ) ₁₇ Si [NH ₂ ] ₃
CH ₃ (CH ₂ ) ₂₅ Si [NH ₂ ] ₃
CH ₃ (CH ₂ ) ₁₄ Si [NH (C ₆ H ₆ )] ₃

CF ₃ (CH ₂ ) ₁₃ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₄ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₅ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₇ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₂₅ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₄ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₇ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₂₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ (CH ₂ ) ₁₄ Si [N (C ₆ H ₆ ) ₂ ] ₃

CH ₃ CH ₂ O (CH ₂ ) ₁₅ Si [N (CH ₃ ) ₂ ] _{3
CF 3 CH 2 O (CH 2} ) 15 Si [N (CH 3) 2] 3
_{CH 3 COO (CH 2) 15} Si [N (CH 3) 2] 3
CH ₃ CH ₂ O (CH ₂ ) ₁₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CH ₃ COO (CH ₂ ) ₁₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ COO (CH ₂ ) ₁₅ Si [N (C ₂ H ₅ ) ₂ ] ₃
CF ₃ (CF ₂ ) ₉ (CH ₂ ) ₂ Si [N (C ₂ H ₅ ) ₂ )] ₃
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si [N (C ₂ H ₅ ) ₂ )] ₃
CF ₃ (CF ₂ ) ₁₃ (CH ₂ ) ₂ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CF ₂ ) ₁₄ (CH ₂ ) ₂ Si [N (CH ₃ ) ₂ ] ₃
CF ₃ (CF ₂ ) ₁₅ CH═CHSi [N (CH ₃ ) ₂ ] ₃

_{CF 3 (CF 2) 4 O} (CF 2) 2 (CH 2) 10 Si [N (CH 3) 2] 3
CF ₃ (CF ₂ ) ₄ CONH (CH ₂ ) ₁₀ Si [N (CH ₃ ) ₂ ] _{3
CF 3 (CF 2) 3 O} [CF (CF 3) CF (CF 3) O] 2 CF (CF 3) -
CONH (CH ₂ ) ₃ Si [N (CH ₃ ) ₂ ] ₃

_{CH 3 (CH 2) 13 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CH 3 (CH 2) 14 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CH 3 (CH 2) 15 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CH 3 (CH 2) 17 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CH 3 (CH 2) 25 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CF 3 (CH 2) 14 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
CF ₃ (CH ₂ ) ₁₅ Si [(N (CH ₃ ) ₂ ] ₂ [N (C ₂ H ₅ ) ₂ ]
CF ₃ (CH ₂ ) ₁₇ Si [(N (CH ₃ ) ₂ ] ₂ [N (C ₂ H ₅ ) ₂ ]
_{CF 3 (CH 2) 25 Si} [(N (CH 3) 2] 2 [N (C 2 H 5) 2]
_{CH 3 (CH 2) 17 Si} [(N (CH 3) 2] [N (C 2 H 5) 2] 2
CF ₃ (CF ₂ ) ₁₃ (CH ₂ ) ₂ Si [(N (CH ₃ ) ₂ ] [(N (C ₂ H ₅ ) ₂ ] _{2
CH 3 (CH 2) 14 Si} [(N (CH 3) 2] 2 [N (C 6 H 6) 2]

_{CH 3 CH 2 O (CH 2} ) 15 Si [N (CH 3) 2] 2 (OH)
_{CF 3 CH 2 O (CH 2} ) 15 Si [N (CH 3) 2] 2 (OH)
_{CH 3 COO (CH 2) 15} Si [N (CH 3) 2] 2 (OH)
These compounds can be used alone or in combination of two or more.

  As for the organometallic compound represented by the formula (I), those not commercially available can be synthesized by a known method. For example, they can be produced by the following method.

In the formula, R ¹ , R ² , M, n, and m have the same meaning as in formula (I), and Y is a leaving group such as a halogen atom, an alkoxy group, a phenoxy group, an acyloxy group, a cyano group, and an isocyanate group. Represents.
That is, by reacting an organometallic compound (1) having a leaving group Y and an amine compound (2) in an organic solvent at 0 to 50 ° C. for 1 to 24 hours in the presence or absence of a base, An organometallic amino derivative (3) can be synthesized.
Examples of the base include organic bases such as triethylamine, diisopropylethylamine, and pyridine; carbonates such as potassium carbonate and potassium hydrogencarbonate. Among these, an organic base is preferable, and when the base is absent, it is preferable to use the amine compound (2) in excess in place of the base. Although the usage-amount of a base is not specifically limited, Preferably, it is 1-2 times mole with respect to Y1 mol in organometallic compound (1).

  The solvent used for the reaction is not particularly limited as long as it is an inert solvent for the reaction. For example, aromatic hydrocarbons such as benzene, toluene and xylene: aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; esters such as methyl acetate and ethyl acetate; diethyl Ethers such as ether, diisopropyl ether, 1,2-dimethoxyethane, tetrahydrofuran (THF), 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc., which were dehydrated Is preferred.

  In any reaction, after completion of the reaction, the desired product can be isolated by carrying out usual post-treatment operations, separation and purification in ordinary organic synthetic chemistry. The structure of the target product can be confirmed by performing NMR spectrum, mass spectrum, IR spectrum measurement, elemental analysis, and the like.

2. Organic Thin Film Forming Solution The organic thin film forming solution of the present invention is not particularly limited as long as it is a solution containing an organometallic compound represented by the formula (I). The organic thin film forming solution can be prepared, for example, by stirring a mixture containing an organometallic compound and an organic solvent.
As the organic solvent, a hydrocarbon solvent, a fluorocarbon solvent, and a silicone solvent are preferable, and a hydrocarbon solvent is more preferable. Especially, a thing with a boiling point of 100-250 degreeC is especially preferable.

Specifically, hydrocarbon solvents such as n-hexane, cyclohexane, benzene, toluene, xylene, petroleum naphtha, solvent naphtha, petroleum ether, petroleum benzine, isoparaffin, normal paraffin, decalin, industrial gasoline, kerosene, ligroin; CBr; _{2 ClCF 3, CClF 2 CF 2} CCl 3, CClF 2 CF 2 CHFCl, CF 3 CF 2 CHCl 2, CF 3 CBrFCBrF 2, CClF 2 CClFCF 2 CCl 3, Cl (CF 2 CFCl) 2 Cl, Cl (CF 2 CFCl ) Fluorocarbon solvents such as ₂ CF ₂ CCl ₃ , Cl (CF ₂ CFCl) ₃ Cl, fluorocarbon solvents such as Fluorinate (product of 3M), Afludo (product of Asahi Glass); dimethyl silicone, phenyl silicone, alkyl Modified silico And silicone solvents such as polyether silicones. These solvents can be used alone or in combination of two or more.

  The content of the organometallic compound in the organic thin film forming solution is not particularly limited, but is in the range of 0.1 to 30% by weight with respect to the organic thin film forming solution from the viewpoint of producing a denser monomolecular film. It is preferable.

3. Hereinafter, a method for forming an organic thin film on a substrate using the organic thin film forming solution of the present invention will be described.

(Base material)
The base material used for the method for forming the organic thin film is not particularly limited. The substrate may not be a substrate having a functional group on the surface that can interact with the molecules forming the organic thin film in the organic thin film forming solution, but the organic thin film in the organic thin film forming solution is formed. A substrate having a functional group capable of interacting with a molecule on the surface is preferable, and a substrate having an active hydrogen on the surface is particularly preferable. When a substrate having active hydrogen on the surface is used, the active hydrogen on the substrate surface and the molecules in the solution for forming an organic thin film easily form a chemisorbed film on the substrate surface due to chemical interaction. Can do. Here, the base material having a functional group capable of interacting with a molecule forming the organic thin film in the organic thin film forming solution is chemically bonded to the molecule forming the organic thin film in the organic thin film forming solution. The base material which has the functional group to obtain on the surface is meant.

Here, active hydrogen refers to those that are easily dissociated as protons, and examples of functional groups containing active hydrogen include a hydroxyl group (—OH), a carboxyl group (—COOH), a formyl group (—CHO), and an imino group (═NH ), An amino group (—NH ₂ ), a thiol group (—SH), etc., among which a hydroxyl group is preferable.

  Specific examples of the base material having a hydroxyl group on the surface thereof include metals such as aluminum, copper, stainless steel, and nickel; glass; silicon wafers; ceramics; paper; natural fibers; leather; and other hydrophilic substances; A base material is mentioned. Especially, the base material which consists of a metal, glass, a silicon wafer, ceramics, paper, natural fiber, and a mineral is preferable.

  For a base material made of a material having no hydroxyl group on its surface such as plastic, diamond, and synthetic fiber, the base material surface is previously treated in an oxygen-containing plasma atmosphere (for example, 100 W for 20 minutes) or corona treated. Thus, a hydrophilic group can be introduced. A substrate made of a polyamide resin or a polyurethane resin has an imino group on the surface, and an active hydrogen of this imino group and an alkoxysilyl group of an organometallic compound undergo a dealcoholization reaction to form a siloxane bond (—Si— Since O-) is formed, no surface treatment is required.

In the case of using a substrate that has no active hydrogen on the surface, the surface of the substrate, previously _{SiCl 4, SiHCl 3, SiH 2} Cl 2, Cl- (SiCl 2 O) b -SiCl 3 ( wherein, b It is also possible to form a silica underlayer having active hydrogen on the surface thereof by contacting with at least one compound selected from (natural number) and then dehydrochlorinating.

(Formation method of organic thin film)
A method for forming the organic thin film is not particularly limited, and examples thereof include a dipping method (dipping method), spray coating, spin coating, roller coating, brush coating, and screen printing. Among these, the dip method is preferable.

The dipping method is a method in which a base material is immersed in a solution containing a thin film substance to form a thin film on the surface of the base material.
Spray coating is a method of forming a thin film on the surface of a substrate by spraying a solution containing the thin film substance onto the substrate.
Spin coating is a method in which a thin film material solution is placed on a substrate placed on a disk, and the disk is rotated to form a uniform liquid film, which is fired to form a thin film.
Roller coating is a method in which a thin film is formed by thinly applying an organic thin film substance solution onto a substrate surface with a roller.
Brush coating is a method in which a thin film is formed by applying a thin organic thin film substance solution onto a substrate surface with a brush.
Screen printing is a method of forming a thin film on a substrate by placing a thin film substance (paste) on a screen (cloth) stretched around a frame and sliding it while applying pressure.
In the case of the dip method, the time for immersing the base material in the organic thin film forming solution depends on the type of the base material and the like, and cannot be generally defined, but can be 5 minutes to 24 hours. Minutes to 10 hours are preferred.

  The method for forming the organic thin film derived from the organometallic compound of the present invention is preferably produced by bringing the substrate into contact with the solution for forming an organic thin film containing the organometallic compound of the present invention by using the dipping method. Thereby, a denser organic thin film with fewer impurities can be rapidly formed.

The method using the dip method will be described below.
The step of bringing the substrate into contact with the solution for forming an organic thin film may be performed for a long time at once, or may be performed in a short time by dividing it into a plurality of times. In addition, ultrasonic waves can be used to promote the formation of the organic thin film.

  The temperature of the organic thin film forming solution when the substrate is brought into contact with the organic thin film forming solution is not particularly limited as long as the solution can maintain stability, but usually the temperature of the solvent used for preparing the solution from room temperature is not limited. The range is up to the reflux temperature. In order to bring the organic thin film forming solution to a temperature suitable for contact, the organic thin film forming solution may be heated, the substrate itself may be heated, or both of them may be heated.

  The method for producing an organic thin film derived from an organometallic compound may include a step of washing the substrate with an organic solvent after the step of forming the organic thin film. If there exists such a washing | cleaning process, the excess reagent and impurity which adhered to the surface of the organic thin film formed at the process of forming an organic thin film will be removed. Moreover, the film thickness of the organic thin film formed on the substrate surface can be controlled by providing such a cleaning process.

The organic solvent in the step of washing with an organic solvent is not particularly limited, but hydrocarbon solvents such as hexane, heptane, octane, nonane, decane, benzene, toluene, xylene and the like are preferable.
The cleaning method is not particularly limited as long as it can remove deposits on the substrate surface. For example, a method of immersing the substrate in an organic solvent as described above; in a vacuum or in the atmosphere under normal pressure Examples thereof include a method of allowing the deposit on the surface of the substrate to evaporate; a method of blowing an inert gas such as dry nitrogen gas to blow away the deposit on the surface of the substrate; and the like. Moreover, since the more outstanding cleaning effect is acquired, it is mentioned as a more preferable method to carry out ultrasonic treatment in the state which immersed the base material in the above-mentioned organic solvent.

  It is preferable to further include a step of drying the washed substrate after the step of washing with the organic solvent. The drying method is not particularly limited, and the solution on the surface of the substrate may be an air knife or the like, may be naturally dried, and can be exemplified by a method such as applying hot air. A method of applying warm air is preferable because the organic thin film is further stabilized by applying heat to the formed organic thin film.

  In addition, even when heat is not applied to the substrate when drying the substrate in the drying step, it is preferable to further include a step of applying heat to the substrate because the organic thin film becomes more stable. Although the temperature to heat can be suitably selected according to stability of a base material and an organic thin film, the range of 40-100 degreeC can be mentioned preferably, for example.

(Organic thin film)
By using the method for producing an organic thin film, an organic thin film such as a monomolecular film, a chemical adsorption film, and a self-assembled film can be obtained.
The organic thin film in the present invention is preferably a monomolecular film in which molecules are arranged in a single layer on the substrate surface, and more preferably a chemical adsorption film and / or a self-assembled film. In the present invention, the self-assembled film means a film formed with an ordered structure without external forcing.

The organic thin film in the present invention preferably has crystallinity. In this case, the crystallinity may be polycrystalline or single crystal.
Examples of the present invention are shown below, but the technical scope of the present invention is not limited to these examples.

[Example 1]
(Synthesis of organometallic compounds)
A thermometer, a condenser, and a stirring blade were set in a 100 ml four-necked flask, charged with 16.2 g of a 2M dimethylamine THF solution (manufactured by Aldrich), and cooled to 5 ° C. with ice water while stirring.
Into this, a solution prepared by dissolving 2.0 g of octadecyltrichlorosilane (manufactured by Gelest Co., Ltd.) in 10 g of dehydrated toluene was added dropwise over 1 hour to carry out the reaction.
Thereafter, the reaction was allowed to proceed at room temperature for 2 hours. The dimethylamine hydrochloride precipitated by the reaction was filtered, washed with dehydrated toluene, and the filtrate was concentrated under reduced pressure. Obtained.
¹ H (NMR, CDCl ₃ , 400 MHz) δ 0.89 (t, 3H), 1.26 (brs, 34H), 2.48 (s, 18H)

(Formation of organic thin film)
0.5 g of tris (N, N-dimethylamino) octadecylsilane obtained was dissolved in 99.5 g of dehydrated toluene to prepare an organic thin film forming solution.
The silicon wafer subjected to UV ozone treatment was immersed in the organic thin film forming solution for 60 minutes, washed with NS Clean 100 and dried at 60 ° C. to obtain an organic thin film forming substrate. When the static contact angle on the film formation surface was measured, it was 110 ° with water and 40 ° with tetradecane.
As a result of X-ray diffraction of this film, the film thickness was 2.39 nm and the surface separation was 0.420 nm. From this result, it was confirmed that the film obtained was a self-assembled monomolecular film (SAM) having crystallinity.
The results are shown in FIGS.

[Comparative Example 1]
(Synthesis of organometallic compounds)
A reaction was performed in the same manner as in Example 1 except that octyltrichlorosilane (manufactured by Aldrich) was used in place of octadecyltrichlorosilane to obtain 2.0 g of tris (N, N-dimethylamino) octylsilane.

(Formation of organic thin film)
0.5 g of tris (N, N-dimethylamino) octylsilane obtained was dissolved in 99.5 g of toluene to prepare an organic thin film forming solution.
The silicon wafer subjected to UV ozone treatment was immersed in the organic thin film forming solution for 60 minutes, washed with NS Clean 100 and dried at 60 ° C. to obtain an organic thin film forming substrate. When the static contact angle on the film formation surface was measured, it was 94.2 ° for water and 7.0 ° for tetradecane. The results of X-ray diffraction are shown in FIG.
The film obtained from this result was not a film having insufficient water repellency and crystallinity.

[Comparative Example 2]
(Synthesis of organometallic compounds)
The reaction was performed in the same manner as in Example 1 except that octadecyldimethylchlorosilane (manufactured by Aldrich) was used instead of octadecyltrichlorosilane to obtain 3.1 g of N, N-dimethylamino-octadecyldimethylsilane.

(Formation of organic thin film)
0.5 g of the obtained N, N-dimethylamino-octadecyldimethylsilane was dissolved in 99.5 g of toluene to prepare an organic thin film forming solution.
The silicon wafer subjected to UV ozone treatment was immersed in the organic thin film forming solution for 60 minutes, washed with NS Clean 100 and dried at 60 ° C. to obtain an organic thin film forming substrate. When the static contact angle on the film formation surface was measured, it showed 94.2 ° for water and 7.4 ° for tetradecane. The results of X-ray diffraction are shown in FIG.
The film obtained from this result was not a film having insufficient water repellency and crystallinity.

Claims (6)

Formula (I)
R ¹ _n MX _mn (I)
(In the formula (I),
R ¹ is an aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group, and a halogenated aliphatic carbon atom having 14 to 30 carbon atoms which may have a substituent or a linking group. Represents a hydrogen group,
M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom;
X represents a hydroxyl group or a —NR ² ₂ group, at least two of X represent a —NR ² ₂ group, and R ² represents a hydrogen atom and a carbon number of 1 to 10 which may have a substituent. An alkyl group or a phenyl group which may have a substituent, R ² may be the same or different, and m represents the valence of M.
n represents any positive integer from 1 to (m−2), and when n is 2 or more, R ¹ may be the same or different. )
An organometallic compound represented by The organometallic compound according to claim 1, wherein the organometallic compound represented by the formula (I) is tris (N, N-dimethylamino) octadecylsilane. The solution for organic thin film formation containing the organometallic compound of Claim 1 or 2. The organic thin film forming solution according to claim 3, wherein the organic thin film is a monomolecular film. Formula (I)
R ¹ _n MX _mn (I)
(In the formula (I),
R ¹ is an aliphatic hydrocarbon group having 14 to 30 carbon atoms which may have a substituent or a linking group, and a halogenated aliphatic carbon atom having 14 to 30 carbon atoms which may have a substituent or a linking group. Represents a hydrogen group,
M represents at least one metal atom selected from the group consisting of a silicon atom, a germanium atom, a tin atom, a titanium atom, and a zirconium atom;
X represents a hydroxyl group or a —NR ² ₂ group, at least two of X represent a —NR ² ₂ group, and R ² represents a hydrogen atom and a carbon number of 1 to 10 which may have a substituent. An alkyl group or a phenyl group which may have a substituent, R ² may be the same or different, and m represents the valence of M.
n represents any positive integer from 1 to (m−2), and when n is 2 or more, R ¹ may be the same or different. )
An organic thin film forming method for forming an organic thin film on the surface of the substrate by bringing a solution for forming an organic thin film containing an organometallic compound represented by the formula: The organic thin film forming method according to claim 5, wherein the organic thin film is a monomolecular film.

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