JPH02255716A - Photochemical production of electrically conductive polymer film formed into pattern shape - Google Patents

Abstract

PURPOSE:To obtain the subject film useful for electronic devices, etc., by forming pyrroles having both hydrophilic and hydrophobic parts into a monomolecular film on a substrate according to a Langmuir-Blodgett(LB) method, dipping the resultant film in a solution containing a specific component, photochemically polymerizing the pyrroles and controlling the film thickness and structural regularity on the molecular level. CONSTITUTION:Pyrroles having both relatively hydrophilic and relatively hydrophobic parts as a monomolecular film are laminated on a substrate according to the LB method and then dipped in a solution containing a light absorbing component capable of exhibiting a higher electrode potential than an oxidation current build-up potential of the pyrroles in an excited state and anions having a smaller number of oxidation than the oxidation current build-up potential of the pyrroles or anions having a smaller number of oxidation in an oxidation-reduction pair capable of exhibiting the higher standard electrode potential than the electrode potential in the excited state of the light absorbing component. The film is subsequently irradiated with light within an absorption spectrum of the light absorbing component through a mask previously engraved with an optional pattern and an electrically conductive part is then formed into an optional pattern shape to afford the objective polymer film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for photochemically producing an improved conductive polymer film having both conductivity and insulation properties.

[Prior Art] As a method for electrochemically manufacturing a patterned conductive polymer film, Japanese Patent Laid-Open No. 61-188414, Japanese Patent Application No. 59-101678, etc. are known.

Further, as a method for photochemically producing the above-mentioned polymer membrane, there is a presentation by Seyo et al. (Proceedings of the 56th Spring Annual Meeting of the Chemical Society of Japan, p. 1030). However, since the former method uses conductive electrodes in a pattern, there is a natural limit to its microfabrication. Furthermore, in the latter method, the ionic light-absorbing component is adsorbed onto the Nafion membrane, so the range of application is limited. Furthermore, in these two methods, the electrode or support membrane is simply immersed in a solution layer, and no regularity is observed in the arrangement of monomer molecules adsorbed on the surface of the electrode or support membrane.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a method for photochemically producing a conductive pyrrole polymer film in an arbitrary pattern with excellent structural regularity and a controlled film thickness at the molecular level. It is to provide.

[Means for Solving the Problems] The present invention provides a method for laminating pyrroles having both a relatively hydrophilic part and a relatively hydrophobic part as a monomolecular film on a substrate by the Langmuir-Brochet method. , a light-absorbing component that exhibits an electrode potential greater than the oxidation current rise potential of pyrroles in an excited state, and an anion having a large oxidation number among a redox pair that exhibits a standard electrode potential smaller than the oxidation current rise potential of pyrroles, or The above-mentioned light is immersed in a solution containing an anion with a small oxidation number among redox pairs that exhibits a standard electrode potential higher than the electrode potential in the excited state of the light-absorbing component, and is passed through a mask with an arbitrary pattern carved in advance. This is a method for photochemically producing a conductive polymer film, characterized in that conductive portions are formed in an arbitrary pattern by irradiating light within the absorption spectrum of an absorption component.

The pyrroles having both a relatively hydrophilic part and a relatively hydrophobic part used in the present invention are hydrophilic in either the 1st, 3rd, or 4th position of the pyrrole skeleton shown below. Refers to a substituent in which a group is bonded and a hydrophobic group is bonded to the 3-position, 4-position, or both. Particularly desirable is a substituent in which a hydrophilic group is bonded to the 1-position and a hydrophobic group is bonded to the 3- and 4-positions.

As the backbone pyrrole, unsubstituted virol or pyrrole derivatives having relatively small substituents are used.

Specific examples of the latter include 3-methylpyrrole, 3-ethylpyrrole, 3n-propylpyrrole, 3-n-butylpyrrole, 3-decylpyrrole, 8-benzylpyrrole, 3-cyclohexylpyrrole, and 3-methoxypyrrole. roll, 3-ethoxyvirol, 3-chloropyrrole, 3-bromovirol, 3-iodopyrrole, N-methylvirol, N-ethylvirol, N-'n-propylvirol, N-n-butylpyrrole, N-phenolpyrrole , and N-(p-tolyl)virol.

There are atoms with lone pairs of electrons, such as pyrrole,
In molecules that are sufficiently hydrophilic, the hydrophilic group may be a hydrogen atom bonded to the 1-position. Furthermore, substituents that function as hydrophilic groups for boat fishing can be listed as follows. That is, unsaturated hydrocarbons, hydroxyl groups, carboxyl groups, amino groups, imino groups, guanidine groups, hydrazine groups, diazonium groups, aldehyde groups, ketone groups, alkoxy groups, ester groups, sulfate ester groups, nitro groups,
These include halogen groups, sulfonic acid groups, phosphoric acid groups, silicic acid groups, aluminic acid groups, possible metal salts of each of the above substituents, and amine salts.

On the other hand, as the hydrophobic group, linear and branched chain compounds having a main chain of 5 or more carbon atoms are preferred. Particularly desirable is a long-chain alkyl group whose main chain has about 8 to 25 carbon atoms.

An example of a substituted virol having both a hydrophilic group and a hydrophobic group is α-(3,4)-dioctadecylpyrroloacetic acid.

In the present invention, Langmuir φ
The Prodget method (LB method) is used. This LB method is a method in which a monomolecular film of surfactant suspended on the surface of a solution and its cumulative film are transferred onto a substrate, and it is possible to control the film thickness, structural regularity, etc. at the molecular level. Make it.

Examples of the substrate used in the present invention include glass, organic polymer resin, and the like. More specifically, organic polymer resins include polymethyl methacrylate, polyacrylonitrile, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polycarbonate, polybutadiene, and polystyrene phthalate.

The LB film thus obtained is immersed in a solution containing a light-absorbing component and anions described below, and photochemical polymerization is performed through a mask in which an arbitrary pattern has been carved in advance.

Next, the light-absorbing component in the present invention may be any compound that exhibits an electrode potential higher than the oxidation current rise potential of virols in an excited state and can oxidize virols. Specific examples include methylene blue thionine, proflavin, neosafranin, and tris(2,2'-bipyridine)ruthenium(II) ion.

The concentration of the light-absorbing component varies depending on the absorption coefficient of the compound used. - For boat fishing, a concentration that makes the absorbance approximately 1 is preferable. If the absorbance is too small, the efficiency of the photochemical reaction will decrease; on the other hand, if the absorbance is too large,
The amount of light-absorbing components may increase, which also has the potential to reduce the efficiency of photochemical reactions.

The anion used in the present invention is an ion having a large oxidation number among redox pairs that exhibits a standard electrode potential lower than the oxidation current rise potential of virols, or a standard electrode potential higher than the excited state electrode potential of the light-absorbing component. Any ion having a small oxidation number among the redox pairs indicating the electrode potential and doped into the polymer film during photochemical polymerization may be used. Specific examples of such anions include the following, including transition metal complex anions. That is, Cl-Br-, 8042-1NO3-01
04-13P4Or(CN)s”, Cr(ox) 3
3-(OX: oxalate ion), Cr (cdta)”
(edta: ethylenediaminetetraacetic acid ion)
, Cr(mat)3'-(mat: malonate ion), Mn(CN)61-Mn(cdta)''
Fe(CN)6'-re(edta)'', re(
cat) 33-(cat: catecholic acid ion)
Co(CN)63-Co(edta)-CoC1(ed
ta)2-Co(NO2)(edta)
'-Co(edta) (ox)'', Co(pdta)
-(pdta: propylene diamine tetraacetic acid ion)
Co(cydta)-(cydta: 1.2-
Cyclohexanediamine-N.

N, N', N'tetraacetic acid ion), Go(tnta)''
(tnta nitrimethylenediaminetetraacetic acid ion) Co(cdtp)''' (cdtp: ethylenediaminetetrapropionate ion), Co(tnta)'''
(tnta: )rimethylenediaminetetraacetic acid ion)
Co(dLpa)” (dtpa diethylenetriaminepentaacetic acid ion), Co(ata)(Cox) 2
-(ata = -trilotriacetate ion), Co(
gly)(aia)″(gly nigericin), Co(g
lygly) 2″″ (glygly nigericylglycinate ion) Co(anal) 3′-1
TI(caL) 3”Cu(pdta)2-C
u(glygly)2-Mo(CN)a'-W(
CN)a'', and WCl5-, etc.

Furthermore, specific examples of electrolytes consisting of these anions include KCI, NaCl, KBr, NaBr, K2 80
4, Na2SO4, Li2804,
KNO3, NaNO3LiN0: + KCl0
<NaC104(C4Ha)NBP4
, K3 Cr(ox)3 , KCr(edta
), KCo (ctlta), NaCo (cdta), K
Examples include Co(pdta) and KCo(cydta).

The concentration of the above anion in the solution is generally 0.001 to
2.0 moldm-', preferably 0.05 to 0.5
sol dm→.

The solvent used in the present invention can be varied depending on the type of light-absorbing component and electrolyte. Generally, water,
Ethyl ether, tetrahydrofuran, 1,4-dioxane, acetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile, benzylnitrile, formamide, N-methylformamide, dimethylacetamide, hexamethylphosphoamide, N-
Methylpyrrolidone, pyridine, dimethyl sulfoxide,
Nitromethane, benzene, nitrobenzene, propylene carbonate, 1,2-dimethoxyethane, acetone,
Sulfolane, methyl ethyl ketone, toluene, xylene, methyl chloride, carbon tetrachloride, and the like are used.

In the present invention, for the purpose of increasing the efficiency of photochemical polymerization reaction,
Dissolved oxygen may be removed from the solvent as much as possible. For this purpose, a gas such as argon or nitrogen may be passed through the solution.

Alternatively, a freeze-thaw-thaw cycle may be performed as many times as necessary.

The mask used in the present invention is not particularly limited, and may be of a type generally used in photolithography. That is, after chromium or chromium oxide is deposited on a glass substrate, or an emulsion liquid for lithography is cast, an etching action is applied.
All you have to do is create a predetermined pattern.

The light source for irradiation may be any source that can sufficiently generate excited species of the light-absorbing component, and general examples include mercury lamps, xenon lamps, halogen lamps, and various lasers. The light emitted from these light sources may be continuous light or pulsed light. Furthermore, for the purpose of removing unnecessary wavelength components, a monochromator-1 interference filter, a cut filter, and any combination of these may be used.

The irradiation time is not constant and varies greatly depending on, among other things, the light-absorbing component, the type of light source, and the reaction conditions.

The polymer membrane obtained by the method of the present invention can be used in many applications such as electronic equipment, electrical switches, and special electrode materials.

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that the present invention is not limited in the least by these Examples.

Example I In the LB film cumulative layer, 5 X 10' cool d
α-(3
, 4-dioctadecylpyrrolo)acetic acid was developed as a monolayer. This was then placed in a compressed state under a surface pressure of 1.5 Nm-''. After 30 minutes, by the LB method,
A pyrrole monolayer was formed on a glass substrate with a clean surface. Furthermore, this method was repeated one after another to accumulate a total of 80 layers of virol monolayers. After thoroughly air-drying, attach the photomask to the substrate and coat it with methylene blue (
1, OX 10-6 mol d+e-3) and KCI (
The sample piece was immersed in a solution containing 0.1 moldg'''3).Next, this sample piece was irradiated with light with a wavelength of 805 tv emitted from a high-pressure mercury lamp through a monochromator for 0.5 hours.The substrate was removed from the solution and optically The pattern image was viewed with a microscope.

Figure 1 shows the sketch. Two adjacent light irradiated parts were randomly selected with the light irradiated part in between, and the electrical resistance between them was measured and found to be 20Ω. On the other hand, two adjacent light-irradiated parts were randomly selected with the light-irradiated part in between, and the electrical resistance between them was measured and found to be 20 MΩ.

Example 2 Thionin (lx
1o-f+ dol di-3) and KCI (0,1
A solution containing mold "') was adjusted to 0.1 dm'. Hereinafter, using this solution, a polymerization reaction was carried out under the same conditions as in Example 1, except that light with a wavelength of 602 nm was irradiated.

When the substrate was removed from the solution and viewed under an optical microscope, the same image as shown in FIG. 1 was observed. As in Example 1, the electrical resistances between the conductive parts and between the insulating parts were measured to be 25Ω and 20MΩ, respectively.

[Effects of the Invention] According to the present invention, film thickness, structural regularity, etc. can be controlled at the molecular level by laminating monomolecular films of viroles according to the LB method and then performing photochemical polymerization. A conductive pyrrole polymer film can be easily created in any pattern. Therefore, this polymeric membrane is useful in more multidirectional applications than before.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sketch of a pattern image observed by observing the conductive polymer film obtained in the example using an optical microscope. The shaded area and the non-shaded area represent the area irradiated with light through the photomicrophone and the area blocked by the photomask, respectively.

Claims (1)

[Claims] After laminating pyrroles, which have both a relatively hydrophilic part and a relatively hydrophobic part, as a monolayer on a substrate by the Langmuir-Brochet method, the oxidation current rise potential in the excited state is higher than that of the pyrroles. A light-absorbing component that shows an electrode potential and an anion with a large oxidation number among a redox pair that shows a standard electrode potential that is smaller than the oxidation current rise potential of pyrroles, or a standard that is larger than the electrode potential in the excited state of the light-absorbing component. By immersing the electrode in a solution containing an anion with a small oxidation number among the redox pairs that indicate the electrode potential, and irradiating the electrode with light within the absorption spectrum of the light-absorbing component through a mask with an arbitrary pattern engraved in advance. , a method for photochemically producing a conductive polymer film, which comprises forming a conductive portion in an arbitrary pattern.