JPS6348281A - Production of thin film of phthalocyanine compound - Google Patents

Abstract

PURPOSE:To obtain an electrodeposited thin film of a phthalocyanine compound useful as a catalyst and an organic electronic material, by dissolving an octaalkoxyphthalocyanine compound in an organic solvent, dipping a conductor into the solution and electrifying the solution using the conductor as a working electrode. CONSTITUTION:A compound of formula (R is 1-18C alkyl; M is H2, Mg, Cr, Mn, Fe, Cu, Zn, Pb, etc.) is dissolved in an organic solvent (e.g. dichloromethane, DMF, etc.), a supporting electrolyte (e.g. LiClO4) is added to the solution and the mixture is filled in an electrolytic cell. A conductor (e.g. Pt, graphite, etc.) and a counter electrode are inserted into the mixture to effect the electrolytic deposition of a thin film of a phthalocyanine compound on the conductor. The process enables the production of a thin film free from binder and having freely controllable thickness. The thin film has uniform composition and sufficiently high adhesivity to the substrate. The compound becomes insoluble in solvents other than concentrated sulfuric acid by the electrolytic deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing an electrodeposited thin film from a thalocyanine compound. More specifically, the present invention relates to a method for producing an electrodeposited thin film useful as a catalyst for various chemical reactions or as an organic electronic material.

BACKGROUND OF THE INVENTION Phthalocyanine compounds have been widely used as blue pigments and catalysts for various chemical reactions. The method of forming a thin film of these phthalocyanine compounds is important in coating various substrates with 7-thalocyanine compounds, and when used as a catalyst, it is important as a means to effectively exert the catalytic function with a small amount of phthalocyanine. Some functions, such as conversion functions, are only expressed when phthalocyanine is made into a thin film. Conventionally, the method of obtaining a thin film of a phthalocyanine compound has been to disperse phthalocyanine particles in a resin and apply it onto a substrate (for example, in ``New Edition Dye Handbook'' edited by the Organic Synthetic Chemistry Association (1973)). .7.20).

However, it is difficult to obtain a thin coating film using this method, and when used as a catalyst, the catalytic function of phthalocyanine is hindered by the contamination of resin.

On the other hand, it is also possible to produce thin films of phthalocyanine compounds by vacuum deposition (for example, Shinji Minami and Hiroharu Sasaki, "Materials from the 1980 Textile and Polymer Materials Research Institute Research Presentation" (November 27, 1980), According to this method, a thin film consisting only of phthalocyanine compounds can be formed, but vacuum deposition requires large-scale and expensive equipment, and the thin film produced is It has the disadvantage of being inferior in strength and peeling off from the substrate even when rubbed with a fingertip.

Most phthalocyanine compounds are extremely poorly soluble in water and organic solvents, and this is also the reason why the above-mentioned particle dispersion method and vapor deposition method are mainly used to form thin films of phthalocyanine compounds. Recently, octaalkoxyphthalocyanines have been discovered to exhibit high solubility in specific organic solvents (for example, Osamu Ohno, Kunihiro Ichimura).

Toshiki Sasaki “Proceedings of the 51st Autumn Annual Meeting of the Chemical Society of Japan”
(September 17, 1986), Chemical Society of Japan, p621
).

If a solution of these octaalkoxyphthalocyanines is used, a thin film can be relatively easily formed on a substrate by a spray method, a casting solvent removal method, etc., but the thin film produced by this method has poor strength and is not homogeneous. It has the disadvantage that it is difficult to obtain a film of high quality.

Problems to be Solved by the Invention An object of the present invention is to provide a manufacturing method that can easily form a thin film consisting only of a phthalocyanine compound and that can obtain a homogeneous thin film with good adhesion to the base nide. That's true.

Means for Solving the Invention The inventors of the present invention have carried out various studies to achieve this objective, and as a result have found that certain octaalkoxyphthalocyanines can be electrodeposited on conductors9. The present invention has been made based on this knowledge.

That is, 9 the present invention is based on the general formula (wherein R is an alkyl group having 1 to 18 carbon atoms)
&4 w Mg * Cr, Mns Fe, Go
, Ns, Cu.

A phthalocyanine compound represented by 2n or pb) is dissolved in an organic solvent, a conductor is inserted into the solution of the phthalocyanine compound, and then a current is applied using the conductor as a working electrode to form a conductor on the conductor. The present invention provides a method for producing a phthalocyanine compound thin film, which comprises electrodepositing the phthalocyanine compound onto the thin film.

The phthalocyanine compound used in the present invention is:

It is represented by the general formula (I) above, and R in the formula 2 is
may be any alkyl group having 1 to 18 carbon atoms, and linear ones are preferred because they provide a particularly homogeneous electrodeposited film. Moreover, M in the formula is Hlt Mg.

Cr, Mn, Fe, Co, Ni, Cu, Z
Any of Pb, Mg, and Zn are preferable because they provide an electrodeposited film with particularly excellent adhesion.

In the method for producing a 7-thalocyanine compound thin film of the present invention, first, an organic solvent solution containing the above-mentioned phthalocyanine compound is prepared. The concentration of the phthalocyanine compound at this time is conveniently in the range of 0.1 to 10 mM. The organic solvent to be used can be arbitrarily selected from among those commonly used as non-aqueous solvents for ordinary electrochemical reactions, taking into consideration the solubility for the phthalocyanine compound2.For example, dichloromethane, acetonitrile, Examples include nitromethane, propylene carbonate, dimethylformamide, dimethyl sulfoxide, etc.
A mixture of two or more types of solvents may be used. In addition, it is necessary to mix a supporting electrolyte into the above phthalocyanine compound solution in order to impart conductivity, but the supporting electrolyte used in this case is one of the 9 commonly used non-aqueous solvents in ordinary electrochemical reactions. For example, lithium salts having C-α-, BF<-, PF6-, etc. as anions, or lithium salts having the same anion (0- , BF4
-, tetramethylammonium with PF6-, etc.
Examples include tetraalkylammonium salts such as tetraethylammonium and tetra-n-butylammonium. The concentration of supporting electrolyte at this time is 0.
A range of 0.05 to 0.5M is advantageously used.

In the present invention, the conductor serving as the substrate on which the thin film of the phthalocyanine compound is formed is used as a working electrode for the electrodeposition reaction as described below, and since this electrodeposition reaction proceeds under anodic polarization, it is dissolved by anodic polarization. It is necessary to be a conductor that does not cause passivation, etc., and materials that meet this condition include noble metals such as platinum, gold, palladium, rhodium, ruthenium, and iridium, carbon materials such as glassy carbon and graphite, and oxidized materials. Examples include conductive glass and conductive ceramics having a surface layer containing tin, indium oxide, or the like. There are no particular restrictions on the shape of these conductors.

In the present invention, secondly, the above-mentioned phthalocyanine compound solution containing a supporting electrolyte is filled into an electrolytic cell, and the above-mentioned conductor used as a working electrode, a counter electrode, and, if necessary, a reference electrode are inserted into the cell.

Next, the 'b electrode is anodically polarized using a constant potential method, a potential scanning method, a constant current method, etc., so that a thin film of at least 1 phthalocyanine compound is electrodeposited on the working electrode. As for the counter electrode and the reference electrode, any one commonly used in ordinary electrochemical measurement methods can be used.The counter electrode is, for example, a noble metal electrode such as platinum or gold, and the reference electrode is, for example, a hydrogen electrode.

Examples include a sweet tooth electrode, a silver-silver chloride electrode, and the like.

The minimum potential of the working electrode required to cause the electrodeposition reaction varies depending on the solvent used and also depends on the structure of the phthalocyanine compound, but as an example, when dichloromethane is used as the solvent, 1.3~1
．． 5V (when using a silver-silver chloride electrode as a reference electrode,
(same below). Therefore, when using the constant potential method, a potential slightly higher than this potential range, for example 1
．． Electrodeposition can be carried out efficiently by setting the potential of the working electrode to about 6 to 2.0M. On the other hand, the potential scanning method is a method in which the working electrode is repeatedly polarized anodically and cathodically. During anodic polarization, the potential is raised to a potential slightly higher than the minimum potential required to cause the electrodeposition reaction described above. An electrodeposited thin film can be produced by scanning. Note that when a reference electrode is not used, electrodeposition is performed by adjusting the voltage between the two working electrodes and the counter electrode. For example, the minimum voltage at which electrodeposition occurs is determined in advance by observing the surface of the working electrode while changing the voltage between the working electrode and the counter electrode. By setting the voltage to a value slightly higher than the above-mentioned minimum value, electrodeposition can be performed efficiently. Although electrodeposited thin films can also be produced by this extra-chamber current method,
In both of the homogeneity and strength of the resulting thin film, those produced by the constant potential method or the potential scanning method are superior.

Effects of the Invention The method for producing a phthalocyanine compound thin film of the present invention utilizes the phenomenon in which a specific phthalocyanine compound is electrodeposited on a conductor, so it is possible to easily produce a thin film made only of a phthalocyanine compound without containing a binder such as a resin. can be manufactured. Furthermore, since it is an electrochemical method, it also has the feature that the film thickness can be freely controlled, for example, by controlling the current application time in the case of a constant potential method, or by controlling the number of scans in the case of a potential scanning method.

The phthalocyanine compound thin film produced according to the present invention is homogeneous, has sufficient adhesion to the substrate, and is practically satisfactory. In particular, according to the potential scanning method, the film thickness is 1
Even if it is extremely thin, on the order of ooX, a sufficiently strong film without pinholes can be obtained. Furthermore, the above phthalocyanine compound becomes insolubilized as a result of electrodeposition and becomes virtually insoluble in solvents other than concentrated sulfuric acid, such as water and organic solvents, so the phthalocyanine compound thin film produced by the present invention is stable even in these solvents. It can be used for.

Example Next, the present invention will be explained in more detail with reference to Examples.

Example 1 A dichloromethane solution containing a phthalocyanine compound having the formula and tetraethylammonium perchlorate at concentrations of 2 mM and 0.1 M, respectively, was prepared. Next 5
Using a glass beaker of 01fLl as an electrolytic cell,
Fill this with 3Q'ml of the above dichloromethane solution,
Furthermore, a platinum plate (10 m
A platinum wire (diameter 0.3 mm) as a counter electrode and a silver-silver chloride electrode (Model H3-2'05C manufactured by Toa Denpa) as a reference electrode were inserted.

Next, combine a potentiostat (HA-501 type manufactured by Hokuto Denko) and a function generator (HB-104 type manufactured by Hokuto Denko) to generate a voltage of 100 m within the range of -1.0V to +1.7V.
When potential scanning was repeated at a scanning speed of V/s (
The potential was a value relative to a silver-silver chloride electrode), and a thin film exhibiting a blue color characteristic of phthalocyanine compounds was gradually formed on the platinum plate. When the potential scanning was stopped after 50 times and the platinum plate was taken out from the solution, a homogeneous thin film with an extremely smooth surface was formed on the platinum plate, and the film thickness of this film was lzo'A. Moreover, this thin film was not peeled off from the platinum plate even by the adhesive tape method.

When the solubility of the thin film prepared above in various solvents was investigated, it was dissolved only in 9% sulfuric acid, and in other solvents 2.
For example, it is extremely poorly soluble in water and organic solvents such as benzene, dichloromethane, acetonyl, dimethylformamide, and dimethyl sulfoxide. On the other hand, the phthalocyanine compound used as a raw material! Since the phthalocyanine compound has a considerable solubility in these organic solvents and media, it is possible that the chemical structure of the phthalocyanine compound used as a raw material is changed by electrodeposition. However, the thin film exhibited a blue color characteristic of phthalocyanine compounds, and the content ratio of Zn and N of this thin film was determined by photoelectron spectroscopy to be 1:8, which was the same as that of the phthalocyanine compound used as a raw material. From this, it is clear that the structure of the phthalocyanine ring itself is maintained, and therefore, even if there is a change in the chemical structure, it is only a partial change, such as a change in the chemical structure of a substituent. It can be expected.

Example 2 0.5 mM each of a phthalocyanine compound having the formula . and tetra-n-butylammonium borofluoride.

A mixed solution of dichloromethane and acetonitrile (volume ratio 1:1) containing a concentration of 0.05M was prepared.

Next, a 5QmJ glass beaker was used as an electrolytic cell, filled with 30ml of the above dichloromethane-acetonitrile mixed solution, and in this solution was added 9 gold plates (10mm x 10mm x 0.5mm) as working electrodes.
A platinum wire (diameter 0.3 mm) as a counter electrode and a silver-silver chloride electrode (H3-205 manufactured by Toa Denpa) as a reference electrode.
Type C) was inserted. Then, using a potentiostat (Hokuto Denko HA-501 model), the potential of the 9 working electrodes was increased by +1.
．． It was set to 7V (potential is for silver-silver chloride electrode)
. After 30 minutes, the electricity was turned off and the gold plate was removed from the solution, and a homogeneous and smooth thin film with a blue color characteristic of phthalocyanine compounds was formed on the gold plate, and the film thickness was 370A. Moreover, this thin film did not peel off from the metal plate even when rubbed strongly with the fingertips. When the solubility of the thin film produced as described above in various solvents was investigated, it was found that it was only soluble in concentrated sulfuric acid, but not in other solvents such as water, benzene, and hexane.

It was extremely poorly soluble in organic solvents such as dichloromethane, ethanol, methanol, acetonitrile, dimethylformamide, and dimethyl sulfoxide.

Patent applicant Kozo Iizuka, Director of the Agency of Industrial Science and Technology Designated representative: Director of the Textile and Polymer Materials Research Institute, Agency of Industrial Science and Technology −°・, Akira Yodai □

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R is an alkyl group having 1 to 18 carbon atoms, M
is H_2, Mg, Cr, Mn, Fe, Co, Ni, Cu
, Zn or Pb) in an organic solvent, then inserting a conductor into the solution of the above phthalocyanine compound, and then applying current to the above conductor as a working electrode. 1. A method for producing a phthalocyanine compound thin film, which comprises electrodepositing the phthalocyanine compound in the form of a thin film.