JPH01242630A - Monomolecular film or monomolecular built-up film having porphyrin structure - Google Patents

Abstract

PURPOSE:To form a monomolecular film or monomolecular built-up film having functions such as photoelectric transduction and magnetism or gas sensing and excellent in mechanical strengths, heat resistance and chemical resistance, by using a polyimide having a porphyrin structure as a constituting component. CONSTITUTION:This monomolecular film or monomolecular built-up film is prepared by using a polyimide having recurring units of formula I {wherein R<1> is a tetravalent aromatic organic group (e.g., a group of formula II or III), R<2> is porphyrin ring-containing bivalent aromatic organic group [e.g., a group of formula IV or V (wherein M is a metal such as Fe, Mg or Pb)]}. This film has functions such as photoelectric transduction and magnetism or gas sensing, excels in mechanical strengths, heat resistance and chemical resistance, and can be applied to, for example, a photoelectric transducing element, a memory and recording element or a gas sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a monomolecular film or a monomolecular cumulative film comprising a polyimide having a porphyrin structure as a constituent component.

[Conventional technology]

In recent years, interest in organic ultra-thin films has increased. Attempts are being made to develop high-performance, highly integrated, and highly efficient devices by taking advantage of the diversity of organic materials and forming ultra-thin films with well-oriented organic molecules.

Methods for forming ultra-thin organic films include the LB (Langmuir-Blodgett) method, vapor deposition method, and casting method.
The method is as follows: /) A uniform monomolecular film and monomolecular cumulative film with controlled film thickness can be formed on the A order.

2) The orientation of organic molecules can be controlled and arranged.

3) Since it can be formed into a film at room temperature and under normal pressure, it can be applied to various organic molecules, and it has advantages such as O 2 which can be easily and inexpensively formed into a film, and is the most promising method. Using this method, it is possible to fabricate not only ultra-thin insulating films but also ultra-thin films with various functions. For example, applications to photoelectric conversion elements, memory materials, conductive materials, display elements, nonlinear optical elements, resist materials, gas sensors, etc. are being actively attempted.

[Problem to be solved by the invention]

However, many monomolecular cumulative films produced to date are
It lacks mechanical, thermal, and chemical stability, which has been a major problem when trying to commercially use it as a functional ultra-thin film.

Various attempts are being made to solve this problem. For example, one example is the production of monomolecular films and monomolecular cumulative films using polymers.

Among them, polyimide thin films recently proposed by the group of the present inventors (for example, Japanese Patent Application Laid-Open No. 62-27313!
As an insulating ultra-thin film with excellent heat resistance, it is expected to be applied to electronic components such as semiconductor devices and separation membranes for hydrogen gas, etc.

The present inventors have developed such polyimide thin films for photoelectric conversion, magnetic properties,
...We have discovered that by introducing a porphyrin ring that has functions such as gas sensing, new monomolecular films and monomolecular cumulative films that solve the above problems can be obtained, and we have completed the present invention. .

[Means to solve the problem]

An object of the present invention is to provide a monomolecular film or a monomolecular cumulative film whose constituent unit is polyimide containing a porphyrin structure having functions such as photoelectric conversion, magnetism, and gas sensing.

That is, the gist of the present invention is to use a polyimide having a repeating unit represented by the general formula (I) (wherein R1 is an organic group with a valence value and R2 is an organic group with a covalent value containing a porphyrin ring) as a constituent component. It exists in a monomolecular film or a monomolecular cumulative film.

The present invention will be explained in detail below.

First, as R1 according to the general formula (I) of the present invention, q
aromatic organic groups. Specifically, aromatic organic groups having adhesive values such as these or substituted derivatives thereof may be mentioned.

On the other hand, examples of R2 include a covalent organic group containing a porphyrin ring, preferably a divalent organic group containing a porphyrin ring having co or more phenyl groups. Specific examples of such R2 include (wherein M is Fe, Co, Ni, Mn, Cr
% Mg *Indicates metals such as Cu and Pb. ) or substituted derivatives thereof.

The monomolecular film or monomolecular cumulative film according to the present invention can be obtained, for example, by the following method.

That is, an organic solvent solution of boriamic acid and an amine having a long-chain alkyl group is spread on a water surface to form a monomolecular film or monomolecular accumulation M of the polyamic acid derivative on the substrate, and then this is coated with imide By carrying out the chemical treatment, a monomolecular film or a monomolecular cumulative film containing polyimide as a constituent component can be obtained.

The above polyamic acid is represented by general formula (II).

(In the formula, R' % R2 has the same meaning as in the general formula (I, 1), n represents an integer of 70 or more.] The polyamic acid represented by the above general formula (n) can be expressed by the following general formula C, U1) ( In the formula, R1 is a tetracarboxylic dianhydride represented as in the general formula (I), and the following general formula (■) H2N -R2-NH2.
・ ・ ・ ・ ・ ・ (IV,) (wherein, R2 is produced from a diamine represented with the same meaning as in general formula (I) by a conventionally known method for producing polyamic acid.

Moreover, the above-mentioned amines having a long-chain alkyl group are represented by the general formula (V) R3-N-R4 1 (V).

In the formula, R3, r, and R' represent a hydrogen atom or an organic group (two of which may form a ring with an alkylene group), and at least one of them represents a long-chain alkyl group.

Examples of organic groups include alkyl groups that may be substituted with aromatic or alicyclic hydrocarbon groups, alkenyl,
Examples include unsaturated groups such as alkynyl groups. In addition, some of the carbon atoms such as alkyl groups may be substituted with other bonding groups, such as 05C◯ and ester groups.

Furthermore, examples of the case where R3, R1', and R5 form a ring include a 3- to 7-membered ring.

Examples of long-chain alkyl groups include octyl, decyl, dodecyl, hexadecyl, eicosyl, tocosyl, tetracosyl, ophtacosyl, triacontyl, and pentatriacontyl groups, with carbon numbers ranging from g to θ.
Alkyl groups up to are preferred. However, some of the carbon atoms in this alkyl group are attached to other bonding groups, such as OlS, C
It may be substituted with O, ester group, etc., and in this case, it is preferable that the total number of carbons and this bonding group is selected from g to 4tO. These long-chain alkyl groups may be branched and may further have double or triple bonds.

Such substituted alkyl groups include, for example, oxaoctadecyl group, thiaoctadecyl group, octadecenyl group, octadecynyl group, etc., corresponding to octadecyl group. The above long-chain alkyl groups are R3, R', R' It is necessary to have at least one of the following, but - is usually sufficient. Further, when forming the ring, the ring may have this long-chain alkyl group.

The method for producing a monomolecular film or a monomolecular cumulative film according to the present invention includes, for example, first spreading an organic solvent solution of the above-mentioned polyamic acid and amines on a water surface, and accumulating it on a substrate to form a polyamic acid derivative. A monomolecular film or a monomolecular cumulative film is formed.

For example, after mixing an organic solvent solution of a polyamic acid represented by the above general formula (If) and an amine represented by the above general formula (V), this solution is spread on a water surface, and then a single molecule is placed on a substrate. This is done by forming a film. The polyamic acid used here may be isolated seven times and then redissolved in an appropriate organic solvent before use, but the polyamic acid used here may be used by redissolving it in an appropriate organic solvent. The polymerization reaction solution obtained by reacting the diamine represented by the general formula (IV) in an organic solvent may be used directly and diluted with an appropriate organic solvent so as to be suitable for subsequent development. Examples of the organic solvent used in the polymerization reaction between the tetracarboxylic dianhydride represented by the above general formula (m) and the diamine represented by the above general formula (IV) include N,N-dimethylformamide, N , N
Examples include -dimethylacetamide, N-methyl-copyrrolidone, -,co'-dimethoxyethyl ether, and the like. In any case, it is preferable that n, which represents the degree of polymerization of the polyamic acid, is 70 or more.
If it is smaller than this, it may not function as a membrane. Examples of organic solvents used for developing organic solvent solutions of polyamic acid derivatives include hydrocarbon solvents such as hexane and octane, aromatic solvents such as benzene, toluene, and xylene, dichloromethane, chloroform, and carbon tetrachloride. Examples include chlorine-based solvents and ether-based solvents such as diethyl ether and diptyl ether, but they must be substantially immiscible with water. It is also possible to use a mixture of these organic solvents and a polar solvent such as dimethylformamide, N,N-dimethylacetamide, N-methyl-1-pyrrolidone, or dimethylsulfoxide. In this case, the organic solvent that is substantially immiscible with water is
If it is less than 70% by volume of the total solvent, it will be difficult and difficult to spread on the water surface, which is not preferable.

The ratio of polyamic acid and amines used is determined by self-supporting,
In other words, the surface pressure (approximately /
(0mN/m or more, usually 1SmN/m or more), the amine is usually used in an amount of 772 mol or more, preferably about the same mol, relative to the polyamic acid. In addition, the concentration of polyamic acid and amines in the organic solvent can be selected as appropriate depending on the type of polyamic acid, amines, solvent, etc., but it is usually 0.
．． / ~ / Ommol/13 or so is selected.

In addition, film materials for the monomolecular film other than the above-mentioned components may be appropriately blended as long as they do not substantially impair the properties of the monomolecular film of the present invention.

Examples of the substrate include ceramics such as quartz and glass, carbon substrates such as glassy carbon, metals such as aluminum, copper, and iron, semiconductors such as silicon and potassium-arsenic, and plastic films such as polyimide films and polysulfone films. However, it is necessary that these substrates be substantially insoluble in water.

In forming a monomolecular film on this substrate, a thin film manufacturing apparatus using the so-called Langmuir-Prodgett method (for example, Contemp-Phys-2!; */θ de,
It is convenient to use the i9g da), and by changing the cumulative number of times the film is applied, it is possible to obtain any film thickness depending on the purpose of use of the film.

Furthermore, the monomolecular film or monomolecular cumulative film of the polyamic acid derivative obtained on the substrate is subjected to an imidization treatment to obtain a polyimide thin film.

There are two types of imidization treatment: heat treatment and chemical treatment, and either of these methods can be selected, or both methods can be used in combination.

In the heat treatment, the substrate on which the monomolecular film or monomolecular cumulative film of the polyamic acid derivative has been formed is gradually heated to VcJθ
It is heated to 0'C.

At this time, it is desirable to carry out under an inert gas atmosphere such as nitrogen or argon. In the chemical treatment, a substrate on which a monomolecular film or a monomolecular cumulative film of a polyamic acid derivative is formed is imidized by immersing it in an organic solvent solution containing a carboxylic acid anhydride. Examples of the acid anhydride used here include acetic anhydride, propionic anhydride, butyric anhydride, and the like. It is effective to use a base such as pyridine together with these acid anhydrides. Further, as the organic solvent that can be used in this method, an organic solvent that does not substantially dissolve the polyamic acid derivative accumulated on the substrate is selected. Examples of such organic solvents include hydrocarbon solvents such as hexane and octane, aromatic solvents such as benzene, toluene, and xylene, chlorine solvents such as dichloromethane, chloroform, and carbon tetrachloride, and diethyl ether and sulfate. Examples include ether solvents such as ether. Immersion of the carboxylic acid anhydride in an organic solvent solution is usually carried out from io to 2
q hours are preferred.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the Examples unless the gist thereof is exceeded.

Example / Polyamic acid solution made by Zeng 0,! ;? G? (0-takoku mmol) tr
ans-diaminotetraphenylporphyrin (s, i
s-bis(9-aminophenyl)-10,-〇-diphenyl-2/H,2JH-porphine) was dissolved in 10 ml of N,N-dimethylacetamide and 0, . 202
? (0,927 mmol) of pyromellitic anhydride was added. This solution f was stirred at 20-23°C for 10 hours to obtain a solution of polyamic acid.

By pouring the reaction solution into a large amount of methanol, a solid of cibolyamic acid was obtained, and N,N-dimethylacetamide (
When the intrinsic viscosity was measured at 30°C in DMA C),
It was O, da 5. Polyamic acid solid 0. θ3632
was collected and diluted with DMAc to make soml. Sara K
This solution was diluted to 700 ml with benzene to prepare a solution for monomolecular film production. The concentration of this solution is / mmol/A
? It is.

Preparation of polyamic acid derivative monomolecular film 0.3 ml of the polyamic acid solution prepared in the previous section and a mixed solution of octadecyldimethylamine in benzene, N, N-dimethylacetamide (/l/mmol/l) 0.
t and mlf were mixed, and 100 μl of this solution was spread on the surface of pure water. The surface pressure-surface area line of the obtained polyamic acid derivative monomolecular film is shown in FIG. Next, the thin film on the water surface is
It was deposited on a quartz substrate using the vertical immersion method under a pressure of 20 mN/m.

Figure 1 shows the visible absorption spectrum when the cumulative number of monomolecular polyamic acid derivative films accumulated on a quartz substrate is varied, and Figure 3 shows the cumulative number of times and the absorption coefficient of II and 70 nm in the visible absorption spectrum. shows the relationship between

Since this graph shows a linear relationship, it can be seen that good accumulation is being performed. In addition, the shape of the absorption spectrum was consistent with that of a thick film of the same polyamic acid derivative, which was separately produced by a normal solvent casting method.

FIG. 9 shows a transmission infrared absorption spectrum of a polyamic acid derivative accumulated on a calcium heptachloride plate. The shape of this spectrum was consistent with that of a thick film of the same polyamic acid derivative, which was separately produced by a conventional solvent casting method.

Preparation of polyimide monomolecular cumulative film The quartz plate on which the polyamic acid derivative prepared in the previous section had been deposited was treated with acetic anhydride, pyridine, and benzene. It was immersed in a solution mixed at a ratio of 72 hours. Figure S shows changes in the visible absorption spectrum of the monomolecular cumulative film after immersion depending on the number of cumulative times.

Also, 99/Ilm in the visible absorption spectrum
FIG. 6 shows the relationship between the extinction coefficient and the cumulative number of times.

Since this graph is a straight line, the cumulative structure of the polyamic acid derivative single molecule cumulative film prepared in the previous section is directly reflected in this polyimide single molecule cumulative film. Also,
The shape of the absorption spectrum was consistent with that of a polyimide thick film produced by immersing a thick film of the same polyamic acid derivative, which was separately produced by a conventional solution casting method, in the aforementioned mixed solvent of acetic anhydride, pyridine, and benzene. .

This indicates that the polyamic acid derivative monomolecular cumulative film was converted into a polyimide monomolecular cumulative film, and that no peeling of the film occurred during the process.

Furthermore, FIG. 7 shows a transmission type infrared absorption spectrum of polyimide accumulated on a calcium fluoride plate. The shape of this spectrum was consistent with that of a thick film of the same polyamic acid derivative separately produced by a conventional solvent casting method, and a polyimide thick film produced by immersing it in the aforementioned mixed solvent of acetic anhydride, pyridine, and benzene. Ellipsometry measurements of the monomolecular cumulative film deposited on the silicon substrate revealed that the refractive index was /,911, and the interlayer distance was 0.4 m.

A11 The above-mentioned polyamic acid was added to 5n0 using the apparatus shown in Figure 5.
The photoconductivity of a polyimide monomolecular stacked film obtained by stacking on two electrodes was investigated. This is a 10mM/aqueous solution as a measurement example. When the monomolecular cumulative film has 7 layers, 5 layers, and 10 layers, the intrinsic quantum yield when applying a potential of o, sV is /, respectively.
7g.

0.92.0. A / Tona υ, you can see that the thinner it is, the better it is. FIG. 7 shows the relationship between the wavelength of irradiated light and the quantum yield. This spectrum is very similar to the visible absorption spectrum described above, indicating that light is efficiently absorbed. Figure 10A shows the relationship between the number of experiments and the photocurrent value when using a polyimide monomolecular cumulative film, and Figure 10B shows the relationship between the number of experiments and the photocurrent value when using a polyimide monomolecular cumulative film. Molecular cumulative film (t-(p-aminophenyl)-10,15°-〇-triphenylruco/)
The figure shows the relationship between the number of experiments and the photocurrent value when using (l:l mixed monomolecular cumulative film of H-porphine and stearic acid). The use of membranes has shown higher durability.

Example λ 0.3 & c of A P (0,'lwa Ommol)
is-diaminotetraphenylporphyrin (Cu (
II)) (!;, 10-bis(guaminophenyl)-
75, coO-ginenyl-2/H,2,3H-porphyrin (Cu(n))'e, dissolved in 6 ml of N,N-dimethylacetamide, 0. /07? (0,'1
90 mmol) of pyromellitic anhydride was added. This f6 solution was stirred at k J o -2s°C for 10 hours to obtain a solution of polyamic acid. Pour the reaction solution into a large amount of methane.
A solid of siboriamic acid was obtained by adding N,
The intrinsic viscosity was measured at 30°C in N-dimethylacetamide (DMAC, 1) and found to be 0.62. 0.091'l?f of polyamic acid solid was collected and diluted with DMAc to obtain Sθml. Further, this solution was diluted with benzene to 700ml to prepare a solution for monolayer production.The concentration of this solution was /mmol/l.

The prepared polyamic acid solution o, yml and a mixed solution of octadecyldimethylamine in benzene, N,N-dimethylacetamide l:l (immo L/l) 0.4
1 nlf was mixed, and 100 μl of this solution was spread on the pure water surface.

The thin film on the water surface was then deposited on a quartz substrate using a vertical immersion method under a pressure of 20 mN/m.

Visible absorption spectrum when changing the cumulative number of polyamic acid derivative single molecule cumulative films accumulated on a quartz substrate, and 1I2J in the cumulative number and visible absorption spectrum,
Since the graph showing the relationship between the extinction coefficients of the 7 layers m is a linear relationship, it can be seen that good accumulation is performed.

In addition, the shape of the absorption spectrum is the same as that of a thick film of the same polyamic acid derivative separately produced by a conventional solvent casting method. The shape was consistent with that of a thick film of the same polyamic acid derivative, which was separately manufactured by a conventional solvent casting method.

A quartz plate on which the prepared polyamic acid derivative had been accumulated was immersed for 2 hours in a solution in which acetic anhydride, pyridine, and benzene were mixed at a ratio of 1:3.

Changes in the visible absorption spectrum of the monomolecular cumulative film after immersion depending on the cumulative number of times, and II in the visible absorption spectrum, ?
Since the graph showing the relationship between the extinction coefficient of /nm and the number of accumulations is a straight line, this polyimide single molecule cumulative film reflects the cumulative structural force of the polyamic acid derivative single molecule cumulative film prepared in the previous section. . In addition, the shape of the absorption spectrum is determined by the shape of the
The results were consistent with those of the polyimide thick film produced by immersing a thick film of the same polyamic acid derivative in the aforementioned mixed solvent of acetic anhydride, pyridine, and benzene. This indicates that the polyamic acid derivative monomolecular cumulative film was converted into a polyimide monomolecular cumulative film, and that no peeling of the film occurred during the process. The shape of the transmission-type infrared absorption spectrum of polyimide accumulated on a calcium fluoride plate was obtained by applying a thick film of the same polyamic acid derivative separately produced by a conventional solvent casting method to the above-mentioned acetic anhydride, pyridine,
The results were consistent with those of polyimide thick films prepared by immersion in a mixed solvent of benzene.

Example 3 c of 0.37 et (OA; g Ommol )
is-diaminotetraphenylporphyrin (r, 10
-bis(guaminophenyl)-15,-〇-diphenyl, 2/H, co3H-porphine) was mixed with 6 ml of N,
Dissolved in N-dimethylacetamide, 0,/2 A
? (0,!; g Ommol) of pyromellitic anhydride was added to this solution at 20-2,! 1 at t'C
The mixture was stirred for 0 hours to obtain a solution of polyamic acid.

When the reaction solution was poured into a large amount of methanol, a solid polyamic acid was obtained from K, and the intrinsic viscosity was measured at 30°C in N,N-dimethylacetamide (DMAc).
It was o,,yo. Polyamic acid solid 0.0g&,
? Collect f and dilute it with % MA C and add it to s o ml
And so. Furthermore, this solution was diluted with benzene to 700 ml and used as a solution for monomolecular film production. The concentration of this solution is %
/rnfnol/J.

0.3 ml of the prepared polyamic acid solution and a mixed solution of octadecyldimethylamine in benzene and N,N-dimethylacetamide l:l (/mmol/l) o, tsm
This solution was spread on the surface of pure water.

Next, the thin film on the water surface was deposited on a calcium fluoride plate under a pressure of 10 mN/m using the vertical immersion method. Transmission infrared radiation of the polyamic acid derivative accumulated on the calcium fluoride plate The shape of the absorption spectrum was consistent with that of the same polyamic acid derivative P thick film separately produced by a conventional solvent casting method.

A quartz plate on which the prepared polyamic acid derivative had been accumulated was immersed for 7.2 hours in a solution containing acetic anhydride, pyridine, and benzene mixed at a ratio of 1:3. The shape of the transmission infrared absorption spectrum of polyimide accumulated on a quartz plate can be determined by applying a thick film of the same polyamic acid derivative, which was separately produced by a conventional solvent casting method, to the aforementioned mixed solvent of acetic anhydride, pyridine, and benzene. It was consistent with that of polyimide thick film prepared by dipping.

〔Effect of the invention〕

The monomolecular film or monomolecular cumulative film of the present invention has functions such as photoelectric conversion, magnetism, and gas sensing, and has mechanical strength and
Excellent heat resistance and chemical resistance. Such monomolecular films or monomolecular cumulative films can be used for photoelectric conversion elements, memory/recording elements,
It can be applied to gas sensors, etc., and has high industrial value.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows the relationship between the surface pressure and area of the polyamic acid derivative monomolecular film in the present invention. FIG. 2 shows the change in the visible absorption spectrum of the polyamic acid derivative single molecule cumulative film depending on the cumulative number of times, and FIG. 3 shows the relationship between the cumulative number of times and the extinction coefficient (Q30 nm) of the polyamic acid derivative single molecule cumulative film.

Figure 4 shows FT-IR of a monomolecular cumulative film of polyamic acid derivatives.
The spectrum is shown. Figure S shows changes in the visible absorption spectrum of a polyimide monomolecular cumulative film depending on the number of cumulative
The figure shows the cumulative number of polyimide monomolecular cumulative films and the extinction coefficient (l
1g/nm). FIG. 7 shows the FT-IFt spectrum of a polyimide monomolecular cumulative film. FIG. S schematically shows an apparatus for measuring photoconductivity of a polyimide monomolecular cumulative film. In the diagram, / represents 5 cumulative polyimide single molecule M.
YLO2 electrode, 2 is the counter electrode (gold wire), 3 is the reference electrode, da is the shutter, S is the spectrometer, 6 is the soow xenon lamp, 7 is the potentiostat, za is the 10mM hydroquinone aqueous solution (pHQ), ' is the recorder show. Figure 7 shows the relationship between the photocurrent and the number of experiments for a photoconductive quantum lufilin-containing monomolecular cumulative film of polyimide (A
: porphyrin-containing polyimide monomolecular cumulative film, B: mixed monomolecular cumulative film of low molecular weight porphyrin and stearic acid)
.

Sender: Mitsubishi Chemical Industries, Ltd. Yoshio Imai Persimmon Hon Miyabi Akira Representative Patent Attorney Hase - (1 other person) On the other hand F, (mN/ln) No. 22 Keicho (nrn) Kō 3 diagram 4 sentences of contribution (ri) Desire 5 ni length (nm) ’*　Otsu　Figure Cumulative collection (wholesale) Meiko Yo branch 1 English 6 diagram Encounter 10 d Sugenjakko (concave)

Claims (1)

[Claims] (1) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (In the formula, R^1 is a tetravalent organic group, and R^2 is a divalent organic group containing a porphyrin ring. A monomolecular film or monomolecular cumulative film whose constituent component is polyimide having a repeating unit represented by (representing an organic group).