JP5132057B2 - Conductive resin capable of optical patterning - Google Patents

Description

  The present invention relates to a conductive resin that can be directly patterned without using a resist.

  As the conductive resin, polyacetylene, polyphenylene, polyphenylene vinylene, polypyrrole and the like are well known. These are used as materials for organic EL (organic electroluminescence), organic FET (organic field effect transistor), batteries, capacitors, etc. Depending on the application, patterning of films made of conductive resin may be necessary. Yes (see Patent Document 1).

For example, an EL element has a structure in which an electrode layer, a hole transport layer, an electron transport layer, and an electrode layer are sequentially laminated on a substrate such as Si. Lamination and patterning must be repeated in sequence. When patterning is performed, a resist is applied on the electrode layer or the like, the resist is first patterned, and then the electrode layer or the like is chemically or physically etched using the resist as a mask.
In addition, the FET element has a structure in which, for example, a gate electrode, an insulating layer thin film, a source electrode, a channel layer, and a drain electrode are stacked in order, and the patterning of each layer is performed by a method similar to that for manufacturing an EL element. Done.

JP 07-176470 A

  If patterning of the conductive film can be directly performed without using a resist, the number of patterning steps can be reduced. Thereby, it becomes possible to improve the production efficiency and yield of a product. Further, since it is not necessary to develop the resist, the amount of the organic solvent used can be reduced, and the burden on the environment can be reduced.

  The problem to be solved by the present invention is to provide a conductive resin capable of direct patterning without using a resist and capable of fine patterning of nanometer order.

In order to solve the above problems, the conductive resin capable of photo-patterning according to the present invention has a ratio of cis-poly (arylene vinylene) to trans-poly (arylene vinylene) of 72/28 or more. The poly (arylene vinylene) having a number average molecular weight of 1500 to 30000 (wherein the arylene includes a heterocyclic compound group in addition to the arylene group).

  In the present application, “conductivity” includes electrical conductivity equivalent to that of a semiconductor.

  The inventor of the present application describes poly (arylene vinylene) having conductivity (wherein arylene includes a heterocyclic compound group in addition to the arylene group), cis-poly (arylene vinylene) is benzene, toluene, chloroform, This cis-poly (arylene vinylene) can be obtained by irradiating light with a wavelength of 200 to 600 nm while easily dissolving in an aromatic or halogen-based or ether-based organic solvent such as methylene chloride or tetrahydrofuran. It was found that the product was hardly soluble in the organic solvent.

  The detailed structure of this product is not clear at present. A spectrum specific to trans-poly (arylene vinylene) is observed by light absorption measurement. However, since trans-poly (arylene vinylene) dissolves in the above organic solvent, this product is trans-poly ( Arylene vinylene) is not considered as such. It is considered that some reaction was caused along with the isomerization reaction to trans-poly (arylene vinylene) by irradiating light of the above wavelength to cis-poly (arylene vinylene). However, since it is clear that the isomerization reaction to the trans isomer occurred by the light irradiation, the light irradiation portion is hereinafter referred to as trans-poly (arylene vinylene) or trans isomer.

  In the present invention, the film is patterned by utilizing the above properties of poly (arylene vinylene). That is, by irradiating 200-600 nm light to a partial region of a film or the like made of cis-poly (arylene vinylene), the light irradiated portion is changed to trans-poly (arylene vinylene), and then aromatic. A pattern such as a circuit is formed by eluting the non-irradiated portion of light into an organic solvent using a system, halogen-based or ether-based organic solvent.

  Since cis poly (arylene vinylene) is more soluble in aromatic, halogen or ether organic solvents than trans, it is irradiated with light by washing with such a solvent. Only the part of the cis body that is not eluted elutes, and the part of the trans body irradiated with light remains as a pattern. And since this trans body has electroconductivity, if the conductive resin of this invention is used, patterns, such as a circuit, can be formed directly.

  Moreover, this trans body also has electroluminescence property of emitting light at a wavelength peculiar to the substance by applying a voltage. Therefore, by performing pattern formation using the conductive resin of the present invention, a light emitting layer of a light emitting device such as an FET or an EL can be formed.

  If the molecular weight of the resin is too large, it will be difficult to elute into the organic solvent even in the unirradiated region (cis-poly (arylene vinylene)), and if the molecular weight of the resin is too small, The number average molecular weight of the resin is set to 1500 to 30000 because it is easily eluted into an organic solvent even in the region irradiated with (trans-poly (arylene vinylene)).

In addition, when a large amount of trans-poly (arylene vinylene) is present in the resin before light irradiation, the resin film will not be sufficiently eluted into the organic solvent in the light unirradiated region. The ratio of (arylene vinylene) to trans-poly (arylene vinylene) should be at least 72/28 .

  If the conductive resin of the present invention is used, patterning can be performed without using a resist. For this reason, it is possible to improve the production efficiency and yield of products such as organic ELs, organic FETs, batteries, and capacitors produced using the conductive resin of the present invention. Further, since it is not necessary to develop the resist, the amount of the organic solvent used can be reduced, and the burden on the environment can be reduced.

The graph which shows the time-dependent change of the ultraviolet visible absorption spectrum by light irradiation of a cis-PPV solution. The graph which shows the time-dependent change of the ultraviolet visible absorption spectrum by light irradiation of a cis-PPV film | membrane. ¹ H NMR spectrum of PPV synthesized by the method of reaction formula (1). (a) An optical micrograph of a PPV film having a line pattern, (b) An optical micrograph of a PPV film having a dot pattern.

The poly (arylene vinylene) used in the present invention has the general formula (1)
(Ar and Ar ′ are the same or different arylene group or heterocyclic compound group, and n is an integer of 1 or more).
Ar and Ar ′ may be an arylene group or a heterocyclic compound group, and the structure thereof is not particularly limited. Examples of the structures of Ar and Ar ′ include chemical formula (1) to chemical formula (17) and derivatives thereof. Can be mentioned.
Here, the positional relationship on the aromatic ring or heterocyclic ring of the two vinyl groups (described in the general formula (1)) bonded to the chemical formulas (1) to (17) is not particularly limited. For example, when Ar or Ar ′ is benzene, the two vinyl groups may have any positional relationship of ortho, meta, and para. In addition, the derivatives of chemical formula (1) to chemical formula (17) are, on these aromatic rings or heterocyclic rings, alkyl groups, aryl groups, alkoxy groups, carbonyl groups, amino groups, nitro groups, etc. instead of hydrogen atoms. This means that the substituent is bonded.

For example, cis-poly (arylene vinylene) represented by the chemical formula (18) (number average molecular weight Mn = 2700, (polydispersity) = (weight average molecular weight) / (number average molecular weight) = 1.79 (polystyrene basis), cis The UV-visible absorption spectrum of a 0.015 mg / mL benzene solution with / trans ≧ 99/1) is as shown in Fig. 1, and time elapses when light is irradiated with a high-pressure xenon lamp (main wavelength: 360 nm). At the same time, cis-poly (arylene vinylene) is isomerized and completely changes from cis to trans in about 150 seconds. This measurement was performed at 23 ° C. in a nitrogen atmosphere with a distance between the sample and the light source of 20 cm and an illuminance of about 0.4 mW / cm ² .

FIG. 2 is made of cis-poly (arylene vinylene) represented by the chemical formula (18) (number average molecular weight Mn = 6900, (polydispersity) = 2.01 (polystyrene basis), cis / trans ≧ 86/14). 5 is a graph showing the change with time of the ultraviolet-visible absorption spectrum of the film (film thickness 100 to 200 nm) by light irradiation. This measurement was performed at 23 ° C. in a nitrogen atmosphere with a distance between the sample and the light source of 5 cm and an illuminance of 260 mW / cm ² . Since the concentration of poly (arylene vinylene) is high, the light irradiation time is longer than that in the solution state and the spectrum is broad, but the shape of the spectrum is the same as in FIG.
This shows that cis-poly (arylene vinylene) is changed to trans-poly (arylene vinylene) by light irradiation even in a solid (film) state.

  In the present invention, poly (arylene vinylene) uses the property that the solubility in a solvent differs depending on the three-dimensional structure for patterning, so that cis-poly (arylene vinylene) can be obtained with high stereoselectivity. is important.

Therefore, the present inventors have also intensively studied a method for obtaining cis-poly (arylene vinylene) with high stereoselectivity.
As a result, the first aromatic compound or heterocyclic compound to which two cis-bromoethenyl groups are bonded, and the second arylene to which one equivalent of two boronic acids is bonded to the first arylene compound or heterocyclic compound A compound or a heterocyclic compound is dissolved in an organic solvent, and 1 to 5 equivalents of a base and a first or second arylene compound or heterocyclic compound are added to the first or second arylene compound or heterocyclic compound. Cis-poly (arylene vinylene) by a reaction using a Suzuki-Miyaura cross-coupling type polycondensation method after adding 0.1 to 10 mol% of palladium catalyst and then heating and stirring at 40 to 120 ° C. under light-shielding conditions Has been found to be obtained with a high stereoselectivity of 99% or more.
The reaction formula (1) specifically shows this reaction.
In this reaction, as the base, sodium hydroxide, potassium hydroxide, barium hydroxide, potassium carbonate, sodium carbonate, potassium phosphate, silver oxide, or an aqueous solution thereof can be used. As the palladium catalyst, tetrakis (triphenylphosphine) palladium, dichlorobis (triphenylphosphine) palladium, dichloro {1,1′-bis (diphenylphosphino) ferrocene} palladium, or the like can be used.

The spectrum of ¹ H NMR (300 MHz, CDCl ₃ ) of poly (arylene vinylene) synthesized by this reaction is shown in FIG. The peak of hydrogen bonded to the carbon adjacent to the oxygen of the alkoxy group (bonded to the benzene ring) appears at 3.5 ppm for cis-poly (arylene vinylene) and 4.1 ppm for trans-poly (arylene vinylene), In FIG. 3, no peak appears at 4.1 ppm. This shows that cis-poly (arylene vinylene) can be obtained with high stereoselectivity according to the above method.

In addition, the present inventors can obtain cis-poly (arylene vinylene) with a stereoselectivity of 66% or more by a reaction represented by the reaction formula (2) using the Hiyama cross coupling type polycondensation method. (Journal of Organometallic Chemistry, (USA), 2003, Vol. 676, pp. 49-54).

  In a region containing a relatively large amount of trans form, the resin remains as it is without being dissolved in the solvent even when light is not irradiated. In particular, when fine patterning on the order of several nanometers is performed, it tends to lead to defects such as the connection of adjacent wirings, so the reaction formula (1) of cis poly (arylene vinylene) can be obtained with high selectivity. The resin must be synthesized by the method. However, in the case where only a relatively rough pattern is produced, it is also possible to use a resin obtained by the reaction formula (2) or other methods.

In the conductive resin of the present invention, by changing the substituent on the aromatic ring or heterocyclic ring of arylene vinylene, it is possible to have properties according to the application such as organic EL, organic FET, battery, capacitor. Depending on the purpose of improving the conductivity of the material, dopants such as halogens such as I ₂ and Br ₂ , alkali metals such as Na and Ka, and sulfonic acids such as p-toluenesulfonic acid, and other compounds, etc. It is also possible to mix with resin.

  In the above description, the case of patterning a circuit or the like with poly (arylene vinylene) as a film has been described. However, after pre-forming poly (arylene vinylene) into a cube shape or the like, light irradiation is performed in the same manner as described above. It is also possible to produce a molded body such as an object by elution with a solvent of a non-irradiated portion.

(Synthesis of cis-PPV (1))
1,4-bis (cis-2-bromoethenyl) benzene (58 mg, 0.20 mmol), 1,4-dioctyloxy-2,5-benzenediboronic acid (86 mg, 0.20 mmol), tetrabutylammonium bromide (65 mg, 0.20 mmol) in toluene (2.0 mL), 3M aqueous potassium phosphate solution (0.2 mL, 0.6 mmol) and tetrakis (triphenylphosphine) palladium (0.23 mg, 0.20 mmol) were added, and the mixture was stirred at 80 ° C. for 24 hours under light-shielding conditions. Stir for hours. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. This gave cis-PPV as a dark orange solid (87 mg, 94% yield).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, it was confirmed that the ratio of cis-PPV to trans-PPV was 99/1 or more. As a result of analysis by GPC, the number average molecular weight was 7200, and the polydispersity was 2.89 (polystyrene basis).

(Synthesis of cis-PPV (2))
1,4-bis (cis-2-bromoethenyl) benzene (58 mg, 0.20 mmol), 1,4-dioctyloxy-2,5-benzenediboronic acid (86 mg, 0.20 mmol), tetrabutylammonium bromide (65 mg, 0.20 mmol) in toluene solution (2.0 mL), 3M potassium phosphate aqueous solution (0.2 mL, 0.6 mmol) and tetrakis (triphenylphosphine) palladium (2.3 mg, 2.0 mmol) were added, Stir for hours. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-PPV was obtained as a dark orange solid (97 mg, yield 99% or more).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, it was confirmed that the ratio of cis-PPV to trans-PPV was 99/1 or more. As a result of analysis by GPC, the number average molecular weight was 3,300, and the polydispersity was 1.53 (polystyrene standard).

(Synthesis of cis-PmPV)
1,3-bis (cis-2-bromoethenyl) benzene (58 mg, 0.20 mmol), 1,4-dioctyloxy-2,5-benzenediboronic acid (87 mg, 0.21 mmol), tetrabutylammonium bromide (65 mg, 0.20 mmol) in toluene solution (2.0 mL), 3M aqueous potassium hydroxide solution (0.2 mL, 0.6 mmol) and tetrakis (triphenylphosphine) palladium (2.3 mg, 2.0 mmol) were added, and 80 ° C. under light-shielding conditions. For 24 hours. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-PmPV represented by the chemical formula (19) was obtained as a brown viscous solid (80 mg, yield 86%).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, it was confirmed that the ratio of cis-PmPV to trans-PmPV was 99/1 or more. As a result of analysis by GPC, the number average molecular weight was 5100, and the polydispersity was 2.13 (polystyrene standard).

(Synthesis of cis-PFVPV)
2,7-bis (cis-2-bromoethenyl) -9,9-dihexylfluorene (59 mg, 0.11 mmol), 1,4-dioctyloxy-2,5-benzenediboronic acid (47 mg, 0.11 mmol), tetrabromide To a toluene solution (1.0 mL) of butylammonium (35 mg, 0.11 mmol), 3M aqueous potassium phosphate solution (0.1 mL, 0.3 mmol) and tetrakis (triphenylphosphine) palladium (0.13 mg, 0.11 mmol) were added, The mixture was stirred at 80 ° C. for 24 hours. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-PFVPV represented by the chemical formula (20) was obtained as a brown solid (75 mg, yield 96%).
When this solid was dissolved in CDCl ₃ and ¹ H NMR measurement was performed, it was confirmed that the ratio of cis-PFVPV to trans-PFVPV was 72/28. As a result of analysis by GPC, the number average molecular weight was 3700, and the polydispersity was 1.46 (polystyrene basis).

(Synthesis of cis-PFPV)
2,7-bis (cis-2-bromoethenyl) fluorene (103 mg, 0.273 mmol), 1,4-dioctyloxy-2,5-benzenediboronic acid (131 mg, 0.273 mmol), tetrabutylammonium bromide (79 mg, 0.27 mmol) mmol) in toluene (1.2 mL), 3M aqueous potassium hydroxide solution (0.24 mL, 0.72 mmol) and tetrakis (triphenylphosphine) palladium (3.1 mg, 2.6 μmol) were added, and the mixture was stirred at 80 ° C. for 24 hours under light-shielded conditions. Stir for hours. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-PFPV represented by the chemical formula (21) was obtained as a deep orange solid (135 mg, yield 90%).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, it was confirmed that the ratio of cis-PFPV to trans-PFPV was 90/10. As a result of analysis by GPC, the number average molecular weight was 7400, and the polydispersity was 2.42 (polystyrene standard).

(Synthesis of cis-MEH-PPV)
1,4-bis (cis-2-bromoethenyl) benzene (79 mg, 0.27 mmol), 1- (2-ethylhexyloxy) -4-methoxy-2,5-benzenediboronic acid (87 mg, 0.27 mmol), odor To a toluene solution (1.2 mL) of tetrabutylammonium bromide (79 mg, 0.27 mmol), 3M aqueous potassium hydroxide solution (0.24 mL, 0.72 mmol) and tetrakis (triphenylphosphine) palladium (3.1 mg, 2.6 μmol) were added, The mixture was stirred at 80 ° C. for 24 hours under light-shielding conditions. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-MEH-PPV represented by the chemical formula (22) was obtained as a deep orange solid (66 mg, yield 68%).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, it was confirmed that the ratio of cis-MEH-PPV to trans-MEH-PPV was 99/1 or more. As a result of analysis by GPC, the number average molecular weight was 6400, and the polydispersity was 2.36 (polystyrene basis).

(Synthesis of cis-[(S) -BMB] PPV)
1,4-bis (cis-2-bromoethenyl) benzene (126 mg, 0.437 mmol), 1,4-bis [(S) -2-methylbutoxy] -2,5-benzenediboronic acid (149 mg, 0.437 mmol) ), Tetrabutylammonium bromide (141 mg, 0.437 mmol) in toluene (4.4 mL), 3M aqueous potassium phosphate (0.44 mL, 1.3 mmol) and tetrakis (triphenylphosphine) palladium (0.51 mg, 0.44 μmol) And stirred at 80 ° C. for 24 hours under light-shielding conditions. The reaction solution was cooled to room temperature and then poured into stirred methanol (50 mL). The precipitate thus deposited was filtered, and the precipitate was washed with methanol. As a result, cis-[(S) -BMB] PPV represented by the chemical formula (23) was obtained as an ocherous solid (159 mg, yield 97%).
When this solid was dissolved in CDCl ₃ and measured by ¹ H NMR, the ratio of cis-[(S) -BMB] PPV to trans-[(S) -BMB] PPV was 99/1 or higher. Was confirmed. As a result of analysis by GPC, the number average molecular weight was 2900, and the polydispersity was 1.60 (polystyrene basis).

  These poly (arylene vinylenes) can emit light by applying a voltage. The emission wavelengths at that time are 510 nm for PPV, 450 nm for PmPV, 499 nm for PPFPV, and 488 nm for PFPV.

(Patterning experiment)
The cis-PPV obtained in the above (Synthesis of cis-PPV (2)) was made into a 15 wt% chloroform solution, dropped on a quartz glass substrate (1 cm x 1 cm x 0.5 mm), and then at 800 rpm for 10 seconds. Subsequently, spin casting was performed at 2000 rpm for 60 seconds to obtain a cis-PPV film having a thickness of 100 to 200 nm. The substrate thus obtained was vacuum-dried at room temperature for 30 minutes, and then a photomask was placed on the film and placed in a cell with a quartz window.
The cell was purged with nitrogen gas, and then irradiated with ultraviolet light (main wavelength 365 nm, illuminance 260 mW / cm ² ) for 30 minutes with a high-pressure xenon lamp. Thereafter, the substrate was taken out and the membrane was immediately washed with chloroform.

  An optical micrograph of the film thus obtained is shown in FIG. As can be seen from FIG. 4, when the conductive resin of the present invention is used, a line pattern having a line width of 50 μm or less (FIG. 4A) and a dot pattern having a diameter of 50 μm or less (FIG. 4B) are formed. Is possible.

In this embodiment although the intensity of ultraviolet light and 260 mW / cm ^2, it is possible to form a pattern weak ultraviolet light intensity than this (for example 35 mW / cm ²⁾ in the conductive resin of any invention .

Claims (5)

A conductive resin for forming a residual pattern,
Poly (arylene vinylene) having a ratio of cis-poly (arylene vinylene) and trans-poly (arylene vinylene) of 72/28 or more and a number average molecular weight of 1500 to 30000 (however, arylene is complex in addition to arylene group) A conductive resin capable of photo-patterning, comprising a ring compound group. The arylene of poly (arylene vinylene) (wherein aryl includes a heterocyclic compound group in addition to the arylene group) is represented by the chemical formulas (1) to (17)
2. The conductive resin capable of photopatterning according to claim 1, wherein the conductive resin has a structure represented by: 1 or a derivative thereof. Poly (arylene vinylene) having a ratio of cis-poly (arylene vinylene) and trans-poly (arylene vinylene) of 72/28 or more and a number average molecular weight of 1500 to 30000 (however, arylene is complex in addition to arylene group) A predetermined region of the resin film containing the ring compound group) is irradiated with light of 200 to 600 nm, and then the non-irradiated portion of the light is irradiated with an organic solvent such as aromatic, halogen, or ether. A method for producing a conductive resin film having a predetermined pattern, wherein the film is patterned by elution with a solvent.   4. The conductive resin film having a predetermined pattern according to claim 3, wherein the aromatic, halogen-based or ether-based organic solvent is any one of benzene, toluene, chloroform, methylene chloride, and tetrahydrofuran. Manufacturing method. Exposure molding resin for forming a residual pattern,
A poly (arylene vinylene) resin having a ratio of cis-poly (arylene vinylene) to trans-poly (arylene vinylene) of 72/28 or more and a number average molecular weight of 1500 to 30000 (however, the arylene is in addition to the arylene group) A resin for exposure molding, comprising a heterocyclic compound group.