JP2009079217A - Novel arylamine polymer - Google Patents

Abstract

で表される繰返し単位を有するアリールアミン重合体。
【選択図】図１Provided is a triarylamine polymer useful for organic electronics that has excellent mobility characteristics and can be formed into a wet film and can be applied to a low-cost process.
The following general formula (I):

An arylamine polymer having a repeating unit represented by:
[Selection] Figure 1

Description

  The present invention relates to a novel poly (triarylamine) useful as a material for various organic electronics such as a photoelectric conversion element, a thin film transistor element, and a light emitting element.

  Various functional elements such as a photoelectric conversion element, a thin film transistor element, and a light emitting element have been proposed by utilizing the light emission characteristics and charge transport characteristics of organic materials. By using an organic material for these elements, it is expected that the maximum advantages of the organic material, such as light weight, low cost, low manufacturing cost, and flexibility, are utilized and the effect is exhibited.

  Among these functional elements, various materials of low molecular weight and high molecular weight have been reported so far as materials for photoelectric conversion elements, particularly hole transport materials for solar cells and electrophotographic photoreceptors. Low molecular weight materials) require higher efficiency, while the latter (high molecular weight materials) require higher printing speed and durability.

  In addition, various materials of low molecular weight and high molecular weight have been reported as materials for light emitting elements. For example, in the case of low molecular weight materials, it has been reported that high efficiency is realized by adopting various laminated structures, and that durability is improved by well controlling the doping method. ing. However, in the case of low molecular weight materials, so-called low molecular aggregates, it has been reported that the film state changes over time over a long period of time, and there is an essential problem regarding the stability of the film over time. ing.

  On the other hand, with respect to polymer materials, until now, vigorous studies have been made mainly on PPV (poly-p-phenylenevinylene) series and poly-thiophene. However, it is difficult to increase the purity of these material systems, and the intrinsically low fluorescence quantum yield is cited as a problem, and the current situation is that a high-performance light-emitting device has not been obtained. .

  Although having the above problems, considering that the polymer material is essentially stable in a glass state, it is possible to construct an excellent light-emitting element if high fluorescence quantum efficiency can be provided. Further improvements are being made in the field. Examples of such a polymer material include a polymer material containing an arylamine unit as a repeating unit (see, for example, Patent Documents 1 to 5 and Non-Patent Document 1).

  On the other hand, various materials of low molecular weight and high molecular weight have been reported for organic thin film transistor elements. For example, pentacene, phthalocyanine, fullerene, anthradithiophene, thiophene oligomer, bisdithienothiophene, etc. are considered for low molecular weight materials, and polymer materials containing polythiophene, polythienylene vinylene, and arylamine units as repeating units are also considered for polymer materials. (Patent Document 6).

  The invention described in Patent Document 6 has been previously proposed by the present inventors. In the polymer materials shown in the prior art including the polymer material having the arylamine unit, the organic electronics material is used. Although the mobility, which is a characteristic value in the above, is remarkable, for example, considering the application to organic electronics materials, particularly organic FET elements, materials with higher mobility are desired.

  In addition, organic materials that can be manufactured at low cost, have sufficient flexibility and strength, are lightweight, and can be increased in area are applied to various functional elements (photoelectric conversion elements, thin film transistor elements, light emitting elements, etc.). In order to take advantage of the maximum feature, the organic material needs to have sufficient solubility in an organic solvent. However, in general, a π-conjugated polymer characterized by a structure in which conjugation is extended often has a rigid structure, which causes a decrease in solubility. Even in the above-described prior art, there are many polymer materials having difficulty in solubility, and various molecular designs have been carried out to avoid this.

WO99 / 20675 Publication (Special Table 2001-520289 Publication) Japanese Patent Laid-Open No. 10-310635 JP-A-8-157575 WO 97/09394 (Special Table 2002-515078) WO03 / 035714 JP 2005-240001 A Synth. Met. , 84, 269 (1997)

The inventors of the present invention have previously described that a polymer material having an arylamine unit having a π-conjugated bond as a main chain (including an ethylene bond) as a repeating unit has excellent luminescent properties and, for example, excellent durability. It was found useful for organic thin film EL devices and as a polymer material for active layers of organic transistors. However, considering the application to organic electronics materials, especially organic FET elements, further improvement in mobility is desired.
The present invention has been made in view of the above prior art, has excellent mobility characteristics, can be formed by a wet method, can be applied to a low-cost process, and is a light-emitting element, FET element, photoelectric conversion element, or the like. An object of the present invention is to provide a triarylamine polymer useful as a material for organic electronics. The mobility characteristic in the present invention is a charge mobility characteristic mainly based on hole transport.

As a result of intensive studies, the present inventors have found that the above problems can be solved by an arylamine polymer containing a specific structural unit, and have reached the present invention.
Hereinafter, the present invention will be specifically described.

  That is, this invention is an arylamine polymer characterized by having a repeating unit represented by the following general formula (I).

In the formula, Ar ₂ and Ar ₃ are divalent groups of a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group. R ¹ , R ² and R ³ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. X, y and z may each represent an integer of 0 to 2, and may be the same or different, and n represents an integer of 1 or more.

  In the arylamine polymer, the present invention is characterized in that the polymer having a repeating unit represented by the general formula (I) is represented by the following general formula (II).

In the formula, Ar ₁ is a monovalent group of a substituted or unsubstituted aromatic hydrocarbon group. R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. X, y and z may each represent an integer from 0 to 2, and may be the same or different; u and v each represent an integer from 0 to 4; It may be different, and n represents an integer of 1 or more.

  Furthermore, the present invention is characterized in that in the arylamine polymer, the polymer having a repeating unit represented by the general formula (II) is represented by the following general formula (III).

In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. Each of x, y and z represents an integer from 0 to 2, each of which may be the same or different, and u and v are each from 0 to 4 An integer, which may be the same or different, w represents an integer from 0 to 5, and n represents an integer of 1 or more.

  Since the arylamine polymer having a repeating unit represented by the general formula (I), (II) or (III) of the present invention is soluble in an organic solvent, low-cost wet film formation is possible. Applicable to low cost processes. As a polymer material for a photoelectric conversion element having high hole transportability and excellent durability, or as a polymer material for a light emitting element having excellent light emission characteristics and excellent durability, and an active layer of a thin film transistor It is particularly useful as a polymer material for use.

The arylamine polymer in the present invention has a repeating unit represented by the general formula (I). Here, in any thiophene, the bonding position with the other is arbitrary. When n is 2 or more, R ³ represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. Z may represent an integer from 0 to 2, and may be the same or different in each thiophene.

  The repeating unit represented by the general formula (I) is represented by the general formula (II). Furthermore, the poly (triarylamine) polymer material is characterized in that the repeating unit represented by the general formula (II) is represented by the general formula (III).

  Moreover, it is preferable that the arylamine polymer in this invention has a repeating unit represented by the following general formula (I ') among the said general formula (I).

In the formula, Ar ₂ and Ar ₃ are divalent groups of a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group. R ¹ , R ² and R ³ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. X, y and z may each represent an integer of 0 to 2, and may be the same or different, and n represents an integer of 1 or more.

  Further, the repeating unit represented by the general formula (I ′) is preferably represented by the following general formula (II ′).

In the formula, Ar ₁ is a monovalent group of a substituted or unsubstituted aromatic hydrocarbon group. R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. X, y and z may each represent an integer from 0 to 2, and may be the same or different; u and v each represent an integer from 0 to 4; It may be different, and n represents an integer of 1 or more.

  Furthermore, it is preferable that the repeating unit represented by the general formula (I ′) is represented by the following general formula (III ′).

In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. Each of x, y and z represents an integer from 0 to 2, each of which may be the same or different, and u and v are each from 0 to 4 An integer, which may be the same or different, w represents an integer from 0 to 5, and n represents an integer of 1 or more.

As described above, the arylamine polymer of the present invention is used as a charge transporting polymer material for an organic transistor, as a polymer material for an organic thin film EL device, or as an organic electronics such as a material for an electrophotographic photoreceptor. It is useful as a material for use.
The method for producing the arylamine polymer of the present invention will be described below.

  Examples of the method for producing an arylamine polymer of the present invention include a cross coupling reaction using an aryl halide and an aryl boron compound (Suzuki Coupling), and a cross coupling reaction using an aryl halogen and an aryl tin compound (Still Coupling). Etc. are preferable.

  The halogen atom of the aryl halide is preferably iodine or bromine from the viewpoint of reactivity. That is, an iodide or bromide is preferable as the aryl halide.

  An aryl boronic acid or aryl boronic acid ester is used as the aryl boron compound. The aryl boronic acid ester is more preferable because it does not produce a cyclic anhydride (boroxin) consisting of a trimer generated when an aryl boronic acid is used, and the synthesized product has high crystallinity and is easily purified. .

  As a method for synthesizing an aryl boronic acid ester, (i) a reaction in which an aryl boronic acid and an alkyl diol are heated in an anhydrous organic solvent, and (ii) a reaction in which an alkoxy boron ester is added after metalation of the halogen moiety of the aryl halide. , (Iii) Reaction of adding an alkoxyboron ester after preparing a Grignard reagent of aryl halogen, and (iv) heating the aryl halide and bis (pinacolato) diboron or bis (neopentyl glycolato) diboron under a palladium catalyst It is obtained by reacting.

As the palladium catalyst, various catalysts such as Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd (OAc) ₂ , PdCl ₂ , or separately adding triphenylphosphine as a ligand to palladium carbon are used. However, Pd (PPh ₃ ) ₄ is most commonly used.

A base is always required for the above reaction, but relatively weak bases such as Na ₂ CO ₃ , NaHCO ₃ , K ₂ CO ₃ give good results. In the case of a reaction system affected by steric hindrance or the like, a strong base such as Ba (OH) ₂ or K ₃ PO ₄ is effective.
In addition, caustic soda, caustic potash, metal alkoxide, etc., for example, potassium t-butoxide, sodium t-butoxide, lithium t-butoxide, potassium 2-methyl-2-butoxide, sodium 2-methyl-2-butoxide, sodium methoxide, sodium Ethoxide, potassium ethoxide, potassium methoxide and the like can also be used.

  Further, a phase transfer catalyst may be used to make the reaction proceed more smoothly, preferably tetraalkylammonium halide, tetraalkylammonium hydrogensulfate, or tetraalkylammonium hydroxide. -n-butylammonium halide, benzyltriethylammonium halide, or tricaprylylmethylammonium chloride.

  Examples of the reaction solvent include alcohols such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2-dimethoxyethane, and bis (2-methoxyethyl) ether, and ether ethers, and cyclic ethers such as dioxane and tetrahydrofuran. Benzene, toluene, xylene, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, and the like.

The reaction temperature of the polymerization reaction is appropriately set depending on the reactivity of the monomer used and the reaction solvent, but it is preferable to keep it below the boiling point of the solvent.
The reaction time in the polymerization reaction can be appropriately set in terms of the reactivity of the monomers used, the molecular weight of the desired polymer, etc., and is preferably 2 to 50 hours, and more preferably 4 to 24 hours.

In the above polymerization reaction operation, a molecular weight regulator or a sealing agent for sealing the end of the polymer (terminal modification group) can be added later to the reaction system in order to control the molecular weight. Or it can be added at the start of the reaction. Therefore, a terminal modifying group derived from a terminator may be bonded to the terminal of the polymer in the present invention.
Examples of the molecular weight regulator or terminal blocking agent include compounds having one reactive group such as phenylboronic acid, bromobenzene, and iodide benzene.

  The molecular weight of the arylamine polymer of the present invention is preferably 1,000 to 1,000,000, more preferably 2000 to 500,000 in terms of polystyrene-equivalent number average molecular weight. When the molecular weight is too small, the film forming property such as the generation of cracks is deteriorated and the practicality becomes poor. On the other hand, if the molecular weight is too large, the solubility in a general organic solvent is deteriorated. For example, the viscosity of the solution becomes high and coating becomes difficult, which is also a practical problem.

  In order to improve mechanical properties, a small amount of a branching agent may be added during polymerization to branch the molecular structure of the arylamine polymer. As the branching agent used, a compound having three or more polymerization reaction active groups (which may be the same or different) is used. These branching agents may be used alone or in combination.

  The arylamine polymer of the present invention obtained as described above is used after removing impurities such as the catalyst, base, unreacted monomer, terminal stopper, or inorganic salt generated during the polymerization. The For the purification of the reaction product, conventionally known methods such as reprecipitation, extraction, Soxhlet extraction, ultrafiltration, dialysis, adsorption with an adsorbent and the like can be used.

The arylamine polymer obtained by the above production method is dissolved in an organic solvent to form a coating solution, and using this coating solution, a spin coating method, a casting method, a dip method, an ink jet method, a doctor blade method, screen printing A thin film can be produced by a known film forming method such as a method, a dispensing method, or spray coating.
The thin films formed by these film formation methods have no cracks and are excellent in strength, toughness, durability, etc., and are suitable as polymer materials for organic electronics such as photoelectric conversion elements, FET elements, and light emitting elements. Can be used.

Specific examples of the arylamine polymer represented by the general formulas (I), (II) and (III) are shown below.
The substituted or unsubstituted monovalent aromatic hydrocarbon group Ar _{1 in the} general formulas (I) and (II) may be any of a monocyclic group and a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group). However, the following can be mentioned as an example. Examples thereof include a phenyl group, a naphthyl group, a pyrenyl group, a fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, a chrycenyl group, a biphenyl group, and a terphenyl group.

Examples of the divalent groups Ar ₂ and Ar ₃ of the substituted or unsubstituted aromatic hydrocarbon group in the general formula (I) include the divalent group of the above substituted or unsubstituted monovalent aromatic hydrocarbon (for example, , Divalent aromatic hydrocarbon groups such as a phenylene group, a naphthylene group, a pyrenylene group, and a fluorenylene group).

In addition, these groups having a cyclic structure (Ar ₁ , Ar ₂ and Ar ₃ ) may have various substituents shown below.
(1) Halogen atom, trifluoromethyl group, cyano group, nitro group.
(2) A linear or branched alkyl group or alkoxy group having 1 to 25 carbon atoms. These may be further substituted with a halogen atom, a cyano group, a phenyl group, a hydroxyl group, a carboxyl group, an alkoxy group, or an alkylthio group.
(3) Aryloxy group: An aryloxy group having a phenyl group or a naphthyl group as the aryl group can be mentioned. These may contain a halogen atom as a substituent, and may contain a linear or branched alkyl group, alkoxy group, or alkylthio group having 1 to 25 carbon atoms. Specific examples include phenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, 4-methylphenoxy group, 4-methoxyphenoxy group, 4-chlorophenoxy group, 6-methyl-2-naphthyloxy group and the like. It is done.
(4) Alkylthio group or arylthio group: Specific examples of the alkylthio group or arylthio group include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(5) Alkyl-substituted amino group: Specifically, diethylamino group, N-methyl-N-phenylamino group, N 2, N-diphenylamino group, N 2, N-di (p-tolyl) amino group, dibenzylamino Group, piperidino group, morpholino group, urolidyl group and the like.
(6) Acyl group: Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.

On the thiophene of the arylamine polymer represented by the general formulas (I), (II) and (III) in the present invention, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, etc. From the viewpoint of improving the solubility in a solvent, it is preferable to have a substituted or unsubstituted alkyl group, alkoxy group or alkylthio group.
If the number of carbons of these substituents increases, the solubility will be improved, but on the other hand, the properties such as charge transportability will decrease, so that the desired properties can be obtained within the range where the solubility is not impaired. It is preferred to select a substituent.

  Examples of suitable substituents in that case include alkyl groups, alkoxy groups and alkylthio groups having 1 to 25 carbon atoms. A plurality of the same substituents may be introduced, or a plurality of different substituents may be introduced. These alkyl groups, alkoxy groups and alkylthio groups are further halogen atoms, cyano groups, aryl groups, hydroxyl groups, carboxyl groups, or linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, alkoxy groups. Alternatively, it may contain an aryl group substituted with an alkylthio group.

Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, Heptyl group, octyl group, nonyl group, decyl group, dodecyl group, 3,7-dimethyloctyl group, 2-ethylhexyl group, trifluoromethyl group, 2-cyanoethyl group, benzyl group, 4-chlorobenzyl group, 4-methyl A benzyl group, a cyclopentyl group, a cyclohexyl group, etc. can be mentioned as an example.
Examples of the alkoxy group and the alkylthio group include those in which an oxygen atom or a sulfur atom is inserted into the bonding position of the alkyl group to form an alkoxy group or an alkylthio group, respectively.

In the arylamine polymer of the present invention, the solubility in a solvent is improved by the presence of an alkyl group or alkoxy group substituent. Improving the solubility of the polymer in the solvent means that the production tolerance in the wet film forming process when forming an organic EL element or an organic transistor element by forming a film using a coating solution in which the polymer is dissolved in the solvent. This is important because it leads to an increase in size.
That is, by improving the solubility, for example, the choice of coating solvent, the temperature range during solution preparation, and the temperature range and pressure range during solvent drying can be expanded. As a result, a high-quality thin film with high purity and high uniformity can be obtained.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited by these examples unless it exceeds the gist.
[Example 1]
<Synthesis of Polymer 1; When n = 1 in General Formula (I)>
Polymerization reaction was carried out under the following conditions along the reaction steps shown in the following reaction formula to synthesize polymer 1.

In a 50 ml three-necked flask, 0.938 g (1.5 mmol) of diboron ester shown in the above reaction formula, 0.861 g (1.5 mmol) of dibromo, and 12.8 mg of Aliquat 336 (manufactured by Aldrich) as a phase transfer catalyst. (0.032 mmol), tetrakistriphenylphosphinepalladium 10.0 mg (0.0087 mmol), and toluene 9 ml were added, and after argon gas substitution, 2 M-sodium carbonate aqueous solution 3.5 ml was added and refluxed for 6 hours, followed by termination reaction. First, 80 mg (0.66 mmol) of phenylboronic acid was added and refluxed for 4 hours, and then 150 mg (0.96 mmol) of bromobenzene was added and refluxed for 4 hours.
Thereafter, the reaction solution was returned to room temperature, and then the organic layer was dropped into a mixed solvent of methanol / water and reprecipitated to obtain a crude polymer. This crude polymer was made into a tetrahydrofuran solution, dropped into a mixed solvent of methanol / water and reprecipitated to obtain a polymer. Next, the obtained polymer was made into a chloroform solution, and 1 g of palladium scavenger silica gel (manufactured by Aldrich) was added thereto and stirred at room temperature for 1 hour to remove residual palladium in the polymer. After the silica gel was filtered off, washing was repeated with ion-exchanged water until the conductivity of the washing liquid became equivalent to that of ion-exchanged water. After washing, the polymer was made into a tetrahydrofuran solution, and the polymer was purified by dropwise addition to methanol and reprecipitation. The yield was 0.925 g, and the yield was 79%.

The number average molecular weight and weight average molecular weight (both polystyrene average molecular weight measured by GPC [gel permeation chromatography]), elemental analysis value (calculated value), and infrared absorption spectrum of the above polymer were measured. It was like.
Number average molecular weight in terms of polystyrene measured by GPC: 35000, weight average molecular weight: 94000,
Elemental analysis value (calculated value); C: 76.24% (76.39%), H: 7.73% (7.56%), N: 1.92% (1.78%), S: 11 .95% (12.33%)
The infrared absorption spectrum (NaCl cast film) is shown in FIG.

[Example 2]
<Synthesis of Polymer 2; When n = 2 in General Formula (I)>
Polymerization reaction was carried out under the following conditions along the reaction steps shown in the following reaction formula to synthesize polymer 2.

In a 50 ml three-necked flask, 0.938 g (1.5 mmol) of diboron ester shown in the above reaction formula, 1.237 g (1.5 mmol) of dibromo, and 12.5 mg of Aliquat 336 (manufactured by Aldrich) as a phase transfer catalyst. (0.031 mmol), 10.0 mg (0.0087 mmol) of tetrakistriphenylphosphinepalladium, and 9 ml of toluene were added, followed by replacement with argon gas, 3.5 ml of 2M-sodium carbonate aqueous solution was added and refluxed for 4 hours, followed by termination reaction. First, 80 mg (0.66 mmol) of phenylboronic acid was added and refluxed for 4 hours, and then 150 mg (0.96 mmol) of bromobenzene was added and refluxed for 4 hours.
Thereafter, the reaction solution was returned to room temperature, and then the organic layer was dropped into a mixed solvent of methanol / water and reprecipitated to obtain a crude polymer. This crude polymer was made into a tetrahydrofuran solution, dropped into a mixed solvent of methanol / water and reprecipitated to obtain a polymer. Next, the obtained polymer was made into a chloroform solution, and 1 g of palladium scavenger silica gel (manufactured by Aldrich) was added thereto and stirred at room temperature for 1 hour to remove residual palladium in the polymer. After the silica gel was filtered off, washing was repeated with ion-exchanged water until the conductivity of the washing liquid became equivalent to that of ion-exchanged water. After washing, the polymer was made into a tetrahydrofuran solution, and the polymer was purified by dropwise addition to methanol and reprecipitation. The yield was 1.10 g and the yield was 71%.

The number average molecular weight and weight average molecular weight (both polystyrene average molecular weight measured by GPC [gel permeation chromatography]), elemental analysis value (calculated value), and infrared absorption spectrum of the above polymer were measured. It was like.
Number average molecular weight in terms of polystyrene measured by GPC: 41400, weight average molecular weight: 116400,
Elemental analysis value (calculated value); C: 76.43% (76.47%), H: 8.46% (8.26%), N: 1.51% (1.35%), S: 12 .23% (12.37%)
The infrared absorption spectrum (NaCl cast film) is shown in FIG.

Example 3
<Synthesis of Polymer 3; When n = 4 in General Formula (I)>
Polymerization reaction was carried out under the following conditions along the reaction steps shown in the following reaction formula to synthesize polymer 3.

  In a 50 ml three-necked flask, 0.698 g (1.2 mmol) of diboron ester shown in the above reaction formula, 1.389 g (1.2 mmol) of dibromo, 7.3 mg (0.060 mmol) of phenylboronic acid, phase transfer As a catalyst, 10.7 mg (0.026 mmol) of Aliquat 336 (manufactured by Aldrich) and 8.6 mg (0.0074 mmol) of tetrakistriphenylphosphine palladium were added, and after substituting with argon gas, 10 ml of toluene deaerated with argon gas and 2.8 ml of 2M-sodium carbonate aqueous solution was sequentially added and refluxed for 3 hours. Then, as a termination reaction, 50 mg (0.41 mmol) of phenylboronic acid was first added and refluxed for 2 hours, and then 120 mg (0.76 mmol) of bromobenzene. ) Was added and refluxed for 2 hours. Thereafter, the reaction solution was returned to room temperature, and then the organic layer was dropped into a mixed solvent of methanol / water and reprecipitated to obtain a crude polymer. This crude polymer was made into a tetrahydrofuran solution, dropped into a mixed solvent of methanol / water and reprecipitated to obtain a polymer. Next, the obtained polymer was made into a chloroform solution, and 1 g of palladium scavenger silica gel (manufactured by Aldrich) was added thereto and stirred at room temperature for 1 hour to remove residual palladium in the polymer. After the silica gel was filtered off, washing was repeated with ion-exchanged water until the conductivity of the washing liquid became equivalent to that of ion-exchanged water. After washing, the polymer was made into a tetrahydrofuran solution, and the polymer was purified by dropwise addition to methanol and reprecipitation. The yield was 1.38 g and the yield was 87%.

The number average molecular weight and weight average molecular weight (both polystyrene average molecular weight measured by GPC [gel permeation chromatography]), elemental analysis value (calculated value), and infrared absorption spectrum of the above polymer were measured. It was like.
The number average molecular weight in terms of polystyrene measured by GPC is 61900, the weight average molecular weight is 175900,
Elemental analysis value (calculated value); C: 75.95% (76.14%), H: 8.41% (8.29%), N: 1.07% (1.06%), S: 14 .37% (14.52%)
The infrared absorption spectrum (NaCl cast film) is shown in FIG.

Example 4
<Synthesis of Polymer 4; n = 6 in General Formula (I)>
Polymerization reaction was carried out under the following conditions along the reaction steps shown in the following reaction formula to synthesize polymer 4.

  In a 50 ml three-necked flask, 0.407 g (0.7 mmol) of diboron ester shown in the above reaction formula, 0.925 g (0.7 mmol) of dibromo, 6.8 mg (0.056 mmol) of phenylboronic acid, phase transfer As a catalyst, 7.3 mg (0.018 mmol) of Aliquat 336 (manufactured by Aldrich) and 5.0 mg (0.0043 mmol) of tetrakistriphenylphosphine palladium were added, and after substituting with argon gas, 10 ml of toluene deaerated with argon gas and After sequentially adding 3.0 ml of 2M aqueous sodium carbonate solution and refluxing for 4 hours, as a termination reaction, first, 40 mg (0.33 mmol) of phenylboronic acid was added and refluxed for 2 hours, and then 90 mg (0.57 mmol) of bromobenzene. ) Was added and refluxed for 2 hours. Thereafter, the reaction solution was returned to room temperature, and then the organic layer was dropped into a mixed solvent of methanol / water and reprecipitated to obtain a crude polymer. This crude polymer was made into a tetrahydrofuran solution, dropped into a mixed solvent of methanol / water and reprecipitated to obtain a polymer. Next, the obtained polymer was made into a chloroform solution, and 1 g of palladium scavenger silica gel (manufactured by Aldrich) was added thereto and stirred at room temperature for 1 hour to remove residual palladium in the polymer. After the silica gel was filtered off, washing was repeated with ion-exchanged water until the conductivity of the washing liquid became equivalent to that of ion-exchanged water. After washing, the polymer was made into a tetrahydrofuran solution, and the polymer was purified by dropping into methanol and reprecipitation. The yield was 0.97 g, and the yield was 93%.

The number average molecular weight and weight average molecular weight (both polystyrene average molecular weight measured by GPC [gel permeation chromatography]), elemental analysis value (calculated value), and infrared absorption spectrum of the above polymer were measured. It was like.
The number average molecular weight in terms of polystyrene measured by GPC is 47100, the weight average molecular weight is 113200,
Elemental analysis value (calculated value); C: 74.09% (74.19%), H: 7.78% (7.65%), N: 1.01% (0.94%), S: 17 0.03% (17.22%)
The infrared absorption spectrum (NaCl cast film) is shown in FIG.

[Application Example 1]
The surface of the p-doped silicon substrate acting as a gate was thermally oxidized to form an SiO ₂ insulating layer having a thickness of 200 nm, the oxide film was removed only on one side, and Al was evaporated on the removed side to form a gate electrode. Next, a solution prepared by dissolving the polymer 1 obtained in Example 1 on a SiO ₂ insulating layer in a mixed solvent of THF / paraxylene = 8/2 so as to be about 1.0 wt%. After spin coating, an organic semiconductor layer was formed by drying. Subsequently, an Au film was deposited on the organic semiconductor layer so as to have a channel length of 30 μm and a channel width of 10 mm to form source / drain electrodes, and a TFT of application example 1 was fabricated.

The fabricated TFT of Application Example 1 was evaluated, and the field effect mobility of the organic semiconductor was calculated using the following formula (a).
Ids = μCinW (Vg−Vth) 2 / 2L (a)
(Where Cin is the capacitance per unit area of the gate insulating film, W is the channel width, L is the channel length, Vg is the gate voltage, Ids is the source / drain current, μ is the mobility, and Vth is the gate that the channel begins to form. (It is the threshold voltage.)
The mobility of the TFT of Application Example 1 produced above was 7.8 × 10 ⁻⁴ (cm ² / Vsec).
The on / off ratio (the ratio of Ids at Vds = −20 V and Vg = −20 V to the minimum Ids observed within the range of Vds = −20 V and Vg = + 10 to −20 V) is 5.1 × 10 ⁴ . The threshold voltage was -1.95V.
As described above, the fabricated TFT of Application Example 1 showed very excellent characteristics.

[Application 2]
The surface of the p-doped silicon substrate acting as a gate was thermally oxidized to form an SiO ₂ insulating layer having a thickness of 200 nm, the oxide film was removed only on one side, and Al was evaporated on the removed side to form a gate electrode. Next, a solution prepared by dissolving the polymer 2 obtained in Example 2 in a mixed solvent of THF / paraxylene = 8/2 so as to be about 1.0 wt% on the SiO ₂ insulating layer. After spin coating, an organic semiconductor layer was formed by drying. Subsequently, an Au film was deposited on the organic semiconductor layer so as to have a channel length of 30 μm and a channel width of 10 mm to form source / drain electrodes, and a TFT of application example 2 was fabricated.

When the TFT of Application Example 2 manufactured in the same manner as Application Example 1 was evaluated and the field effect mobility, on / off ratio, and threshold voltage were determined, the mobility of the manufactured TFT was 1.2 × 10 ⁻³ (cm ² / Vsec), the on / off ratio was 4.4 × 10 ⁴ , and the threshold voltage was −1.79V.
As described above, the fabricated TFT of Application Example 2 showed very excellent characteristics.

  As described above, the arylamine polymer of the present invention has high hole transportability, excellent mobility characteristics, wet film formation, and adaptability to low-cost processes. It is useful as a material for organic electronics of devices and light emitting devices.

2 is an infrared absorption spectrum diagram of the polymer obtained in Example 1. FIG. 3 is an infrared absorption spectrum diagram of the polymer obtained in Example 2. FIG. 2 is an infrared absorption spectrum diagram of the polymer obtained in Example 3. FIG. 4 is an infrared absorption spectrum diagram of the polymer obtained in Example 4. FIG.

Claims (3)

The polymer which has a repeating unit represented by the following general formula (I).

(In the formula, Ar ₂ and Ar ₃ are divalent groups of a substituted or unsubstituted aromatic hydrocarbon group,
Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group.
R ¹ , R ² and R ³ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. However,
x, y and z each represent an integer from 0 to 2 and may be the same or different;
n represents an integer of 1 or more. ) The polymer having a repeating unit according to claim 1, wherein the polymer having a repeating unit represented by the general formula (I) is represented by the following general formula (II).

(In the formula, Ar ₁ is a monovalent group of a substituted or unsubstituted aromatic hydrocarbon group,
R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. Can be the same or different,
x, y and z each represent an integer from 0 to 2 and may be the same or different;
u and v each represent an integer from 0 to 4 and may be the same or different;
n represents an integer of 1 or more. ) The polymer having a repeating unit according to claim 2, wherein the polymer having a repeating unit represented by the general formula (II) is represented by the following general formula (III).

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. Represents a group selected from the groups, which may be the same or different,
x, y and z each represent an integer from 0 to 2 and may be the same or different;
u and v each represent an integer from 0 to 4 and may be the same or different;
w represents an integer of 0 to 5, and n represents an integer of 1 or more. )

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