JP2002308984A - Novel polymer, its manufacturing method and electric charge transfer material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel polymer showing excellent solubility to a solvent, capable of easily forming a thin film and useful for an electronic material and other resin materials, to provide its manufacturing method and to obtain an electric charge transfer material containing the polymer. SOLUTION: The novel polymer has a structure unit represented by formula (1) or has a structure unit represented by formula (1) and a structure unit represented by formula (2) (wherein, in formula (1), R<1> and R<2> are each independently an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group; (m) is an integer of 0 to 2; and (n) is an integer of 0 to 3; and in formula (2), R<3> and R<4> are each independently hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a disphenylamino group; and (p) is an integer of 0 to 3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymer, a method for producing the same, and a charge transporting material. The present invention relates to a charge transport material containing the polymer.

[0002]

2. Description of the Related Art Conventionally, various organic polymer materials have been used as electronic parts and other electronic materials. Examples of such organic polymer materials include side chain polymers such as polyvinylcarbazole and polyamine, polyphenylenevinylene, and the like.
Thermoplastic polymers such as main-chain polymers such as polyfluorene, polythiophene, polyaniline, and polypyrrole are known. As polymers having excellent charge transporting properties, polyphenylene, alkoxy-substituted polyphenylenevinylene, polyfluorene copolymer having a bulky substituent, and the like have been developed. However, the above-mentioned organic polymer material generally has low solubility in a solvent and it is difficult to prepare a coating solution, so that it has been extremely difficult to form a thin film using the organic polymer material.

[0003] For these reasons, as a material for forming a thin film, a thermosetting resin precondensate or a low-molecular compound is used. However, in the thermosetting resin precondensate, it is possible to form a thin film having excellent heat resistance, but it takes a considerable time for molding, and the thermosetting resin precondensate reacts. At this time, since a low molecular condensate such as water is generated, there is a great limitation in using it as an electronic material. In addition, addition-type oligomers and the like have been developed as materials that do not generate low-molecular condensates.However, when preparing a coating solution, a very special reaction solvent is required, and when forming a thin film, In addition, there is a problem that productivity is extremely low because heat treatment at a high temperature is required. Further, it is difficult to form a thin film having excellent heat resistance with a low molecular compound.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to form a thin film easily with excellent solubility in a solvent. It is an object of the present invention to provide a novel polymer useful as an electronic material and other resin materials. A second object of the present invention is to provide a method capable of producing a novel polymer which is excellent in solubility in a solvent, can easily form a thin film, and is useful as an electronic material and other resin materials. It is in. A third object of the present invention is to provide a charge transport material that has excellent solubility in a solvent, can easily form a thin film, and has high charge transport performance.

[0005]

The polymer according to the present invention comprises a structural unit represented by the following general formula (1).

[0006]

Embedded image

[In the general formula (1), R ¹ and R ²
Each independently represents an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. m is an integer of 0 to 2, and n is an integer of 0 to 3. ]

Further, the polymer of the present invention comprises a structural unit represented by the above general formula (1) and a structural unit represented by the following general formula (2).

[0009]

Embedded image

[In the general formula (2), R ³ and R ⁴
Each independently represents a hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. p is an integer of 0-3. ]

In the polymer having the structural unit represented by the general formula (2), the proportion of the structural unit represented by the general formula (1) in all the structural units is preferably at least 5 mol%. .

The polymer of the present invention preferably has a weight average molecular weight of 5,000 to 100,000 in terms of polystyrene.

The method for producing a polymer according to the present invention is characterized in that a compound represented by the following general formula (3) is subjected to ring-opening polymerization.

[0014]

Embedded image

[In the general formula (3), R ¹ and R ²
Each independently represents an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. m is an integer of 0 to 2, and n is an integer of 0 to 3. ]

The method for producing a polymer of the present invention is characterized in that the compound represented by the above general formula (3) and the compound represented by the following general formula (4) are subjected to ring-opening copolymerization. I do.

[0017]

Embedded image

[In the general formula (4), R ³ and R ⁴
Each independently represents a hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. p is an integer of 0-3. ]

The charge transport material of the present invention is characterized by containing the above-mentioned polymer.

[0020]

Embodiments of the present invention will be described below in detail. The polymer of the present invention comprises a structural unit represented by the above general formula (1) (hereinafter referred to as “structural unit [A]”).
Also called. ) Or the structural unit [A] and the structural unit represented by the general formula (2) (hereinafter, also referred to as “structural unit [B]”). The compound represented by the above formula (4) by ring-opening polymerization of the compound represented by 3) (hereinafter, also referred to as “specific epoxide [a]”) or the specific epoxide [a] (Hereinafter, also referred to as "specific epoxide [b]").

In the general formula (1) showing the structural unit [A] and the general formula (3) showing the specific epoxide [a],
The groups R ¹ and R ² are an alkyl group (preferably having 1 to 8 carbon atoms), an aryl group such as a phenyl group, a monophenylamino group or a diphenylamino group, and the groups R ¹ and R ² are the same. Or different. Among these, a methyl group, an ethyl group, a butyl group, a phenyl group, and a polymer having excellent properties such as solubility, productivity, heat resistance and charge transport performance are obtained.
A biphenyl group and a diphenylamino group are preferred. The value of n indicating the number of repeating methylene groups is 0 to 3, preferably 0.
~ 2. The value of m indicating the number of groups R ¹ and R ² is 0
To 2, preferably 0 or 1, and the number of groups R ^{1 and} the number of groups R ² may be the same or different. Further, the position of the substituted or unsubstituted diphenylamino group in the general formulas (1) and (3) may be any of ortho-, meta- and para-, but the para-position is preferable.

Preferred specific examples of the specific epoxide [a] include glycidyl 4-diphenylaminophenyl methyl ether, glycidyl 4-diphenylaminophenylethyl ether, glycidyl 4-ditolylaminophenyl methyl ether, glycidyl 4-phenyltolylamino Phenylmethyl ether, glycidyl 4- {bis (biphenylamino) phenyl} methyl ether and the like.

General formula (2) representing a specific structural unit [B]
In the general formula (4) showing the specific epoxide [b] and the group R ³ and the group R ⁴ , a hydrogen atom, an alkyl group (preferably having 1 to 8 carbon atoms), an aryl group such as a phenyl group, monophenylamino Group or diphenylamino group, and the groups R ³ and R ⁴ may be the same or different. Among these, solubility,
A hydrogen atom, an ethyl group, a phenyl group, a biphenyl group, and a diphenylamino group are preferable in that a polymer excellent in various properties such as productivity, heat resistance, and charge transport performance can be obtained.
The value of p indicating the number of repeating methylene groups is 0 to 3, preferably 0 to 2. The position of the substituted or unsubstituted carbazolyl group in the general formulas (2) and (4) may be any of ortho-, meta-, and para-, but is preferably the para-position.

Preferred specific examples of the specific epoxide [b] include glycidyl 4-carbazolylphenyl methyl ether, glycidyl 4-diethylcarbazolyl phenyl methyl ether, glycidyl 4-diphenylcarbazolyl phenyl methyl ether, and glycidyl 4 -Diphenylaminocarbazolylphenyl methyl ether, glycidyl 4-carbazolylphenylethyl ether and the like.

The method for producing the specific epoxide [a] and the specific epoxide [b] is not particularly limited, but as a method for easily producing it, epichlorohydrin and the following general formula (5) ) Or a compound represented by the following general formula (6).

[0026]

Embedded image

[In the general formula (5), R ¹ and R ²
Each independently represents an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. m is an integer of 0 to 2, and n is an integer of 0 to 3. In the general formula (6), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. p is an integer of 0-3. ]

In the polymer comprising the specific structural unit [A] and the specific structural unit [B], the ratio of the specific structural unit [A] is preferably at least 5 mol%, more preferably 20 mol%. % Or more. When the proportion of the specific structural unit [A] is less than 5 mol%, the obtained polymer may have poor solubility.

The average molecular weight of the polymer of the present invention is appropriately selected according to the purpose of use. However, in terms of obtaining good mechanical properties, solubility and processing properties, the average molecular weight is calculated in terms of polystyrene by gel permeation chromatography. It is preferable that the weight average molecular weight is 5,000 to 100,000.

In the method for producing a polymer of the present invention, a specific epoxide [a] is subjected to ring-opening polymerization, or a specific epoxide [a] and a specific epoxide [b] (hereinafter, both are collectively referred to). (Also referred to as "specific epoxide") to produce a polymer. In such a production method, as the catalyst,
An acid catalyst or an alkali catalyst generally used for ring-opening polymerization of an epoxide can be used. However, when an acid catalyst is used, caution is required because the reaction system may gel during the progress of polymerization. Therefore, it is preferable to use an alkali catalyst as the catalyst.

As the acid catalyst, Bronsted acid and Lewis acid can be used. Specific examples of the acid catalyst include:
Inorganic acids such as hydrochloric acid, HBr and sulfuric acid; Bronsted acids composed of organic acids such as oxalic acid and acetic acid; metal chlorides such as boron trifluoride and aluminum chloride; metal oxides such as aluminum oxide; triethyl aluminum and dialkyl aluminum Lewis acids composed of halogenated organometallic compounds such as halides, monoalkylaluminum dihalides and aluminum sesquichlorides can be mentioned.

As the alkali catalyst, various catalysts, for example, metal hydroxide, alkali metal alkoxide, tertiary amine and the like can be used. Preferred specific examples of the alkali catalyst include sodium hydroxide, potassium hydroxide,
Metal hydroxides such as cesium hydroxide, sodium methoxide, sodium ethoxide, sodium-tert-
Butoxide, potassium methoxide, potassium ethoxide, lithium-tert-butoxide, sodium-t
alkali metal alkoxides such as tert-butoxide, potassium-tert-butoxide and the like, which may be added to the reaction system as they are, alkali metals, alkali metal hydrides or alkali metal hydroxides;
The target catalyst may be prepared by adding an alcohol to the reaction system and reacting both.

The use amount of such a catalyst is not particularly limited, but is not particularly limited, but is 0.001 to 1 mol of a specific epoxide as a monomer.
It is preferably in the range of 2 to 2 mol, and particularly preferably in the range of 0.01 to 1 mol.

In the production method of the present invention, the ring-opening polymerization of a specific epoxide is usually performed in an inert solvent. The inert solvent is not particularly limited as long as it does not significantly inhibit the ring-opening polymerization of the specific epoxide,
For example, aromatic hydrocarbon solvents such as benzene, toluene, xylene and mesitylene; ether solvents such as diethyl ether, tetrahydrofuran and dioxane; halogenated solvents such as acetonitrile, dimethylformamide, dimethyl sulfoxide, hexamethylphosphottriamide, methylene chloride and the like. Can be mentioned as preferable specific examples, and among these, aromatic hydrocarbon solvents such as benzene, toluene, xylene and mesitylene are particularly preferable. It is important that the above-mentioned solvent is sufficiently dehydrated.

In the production method of the present invention, the ring-opening polymerization of a specific epoxide is usually carried out under normal pressure in an atmosphere of an inert gas such as nitrogen or argon, but may be carried out under pressure. As specific polymerization conditions, for example, the reaction temperature may be preferably selected from the range of -40 ° C to 250 ° C, more preferably from the range of 20 ° C to 150 ° C, and the reaction time is preferably several minutes to 150 ° C. The time can be selected from a range of time.

The polymer thus obtained can be used as it is as an electronic material or other resin material, but fillers such as glass fiber, carbon fiber, talc, calcium carbonate, mica, various pigments, oxidized It can be used in the state of being mixed with various stabilizers such as an inhibitor and a light stabilizer to form a composition. In addition, general-purpose resins such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene; engineering plastics such as polyamide and modified polyphenylene ether; It can be used by blending or alloying with a polymer.

According to the polymer of the present invention, excellent solubility in a solvent can be obtained, and a coating solution for forming a thin film can be easily prepared. A thin film can be formed. Therefore, the polymer of the present invention is useful as an electronic material or other resin material. In particular, since the polymer has a tertiary aromatic amine skeleton or a carbazole skeleton in its chemical structure, it has excellent charge transport performance. Is very suitable as a charge transport material.

When the polymer of the present invention is used as a charge transporting material, examples of the charge transporting material include polyvinyl carbazole, poly (4-vinylphenyl) carbazole, polyvinyl triphenylamine, vinyl carbazole and 2- (4 -Vinylphenyl) -5-naphthyl-1,
Examples thereof include known polymers having a hole-transporting ability such as a copolymer with 3,5-oxadiazole. Preferably, poly (4-vinylphenyl) carbazole, polyvinyltriphenylamine, and vinylcarbazole are used. 2-
(4-vinylphenyl) -5-naphthyl-1,3,5-
Other polymers having charge transport performance such as oxadiazole may be contained. In addition, charge transport materials include:
Various dyes, laser dyes and the like, for example, 0.1 to 10
It may be contained at a ratio of mass%.

[0039]

EXAMPLES Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

[Synthesis of Specific Epoxide] <Synthesis Example 1 (Synthesis of Specific Epoxide [a])> (1) In a 200 ml two-necked flask equipped with a cooling tube and a thermometer, potassium carbonate was added at room temperature. Aqueous solution 1
ml and 0.25 g of sodium boron hydride (6.
4 mmol) was added to 100 ml of an ethanol suspension in which 5 g (18.3 mmol) of 4-diphenylaminobenzaldehyde was suspended, and reacted by stirring at room temperature for 3 hours. After confirming that the reaction was completed by high performance liquid chromatography (HPLC), the reaction solution was concentrated to 30 ml with a suction device, and the obtained concentrated solution was poured into water, followed by solvent extraction using ethyl acetate. The oil layer (ethyl acetate solution) was recovered and dehydrated using magnesium sulfate. The ethyl acetate solution was concentrated to obtain 4.8 g of a concentrated solution, which was dissolved in a mixed solvent of hexane and toluene and recrystallized to obtain 4.5 g of colorless needle crystals. Analysis of the colorless needle crystals confirmed that it was 4-hydroxymethyl-trifluoroamine.

(2) 2.0 g (7.3 mmol) of 4-hydroxymethyl-triphenylamine obtained in the above (1)
l), 4-hydroxymethyl-triphenylamine and epichlorohydrin were reacted by stirring at room temperature 12% of a 50% aqueous sodium hydroxide solution, 4 g (43 mmol) of epichlorohydrin and 160 mmol of benzyltrimethylammonium chloride. After confirming that 4-hydroxymethyl-triphenylamine had disappeared from the reaction system by high performance liquid chromatography (HPLC), about 20 ml was added to the reaction system.
To the extent of toluene was added, and the organic layer (toluene solution) was thoroughly washed with water. Next, the organic layer was separated and collected, and after dehydration treatment using magnesium sulfate, the solvent was distilled off to obtain 2.1 g of a yellow oily product. Thereafter, the product was purified by silica gel column chromatography.

[0042] The purified product was obtained from JEOL Ltd. 9
Analysis by a 0 MHz nuclear magnetic resonance analyzer and an infrared spectrometer manufactured by JASCO Corporation confirmed that it was glycidyl 4-diphenylaminophenyl methyl ether represented by the following formula (A). The nuclear magnetic resonance spectrum of the product is shown in FIG.

[0043]

Embedded image

<Synthesis Example 2 (Synthesis of Specific Epoxide [b])> In Synthesis Example 1, 4-carbazolylbenzyl alcohol was used in place of 4-hydroxymethyl-triphenylamine prepared in (1). Reaction with epichlorohydrin was performed in the same manner except that the product was recovered, and the product was recovered and purified.

The purified product was purified using a 9
Analysis by a 0 MHz nuclear magnetic resonance analyzer and an infrared spectrometer manufactured by JASCO Corporation confirmed that it was glycidyl 4-carbazolylphenyl methyl ether represented by the following formula (b). . FIG. 2 shows a nuclear magnetic resonance spectrum of the product.

[0046]

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Example 1 In a 50 ml two-necked flask equipped with a condenser and a thermometer, 1 g (3 mmol) of the synthesized glycidyl 4-diphenylaminophenyl methyl ether was added to 5 ml of xylene at room temperature. Further, 0.2 g of potassium hydroxide (4 m
mol), and the mixture was polymerized under a nitrogen stream at 90 ° C. for 32 hours. Next, after confirming that 4-{(oxiranylmethoxy) methyl} triphenylamine had disappeared from the reaction system by high performance liquid chromatography (HPLC), toluene was added to the reaction solution, and the reaction solution was washed with water. Was repeated. After dehydrating the reaction solution by a conventional method, the reaction solution was poured into a large amount of methanol to coagulate the product, and the coagulated product was dissolved in a solvent. The coagulation-dissolution operation of this product was repeated to obtain 0.8 g (yield 80%) of a yellow powdery polymer (polyglycidyl 4-diphenylaminophenylmethyl ether). FIG. 3 shows a nuclear magnetic resonance spectrum of the obtained polymer.
Shown in Further, the average molecular weight in terms of polystyrene of the obtained polymer was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a carrier. As a result, the number average molecular weight was 3,100 and the weight average molecular weight was 6,700.

Example 2 In Example 1, glycidyl 4-diphenylaminophenyl methyl ether was replaced with an equimolar mixture of glycidyl 4-diphenylaminophenyl methyl ether and glycidyl 4-carbazolylphenyl methyl ether. A polymer was obtained in the same manner as above except for the following. FIG. 4 shows a nuclear magnetic resonance spectrum of the obtained polymer. The obtained polymer was measured for average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a carrier. As a result, the number average molecular weight was 4,800 and the weight average molecular weight was 10,600.

[Solubility test] The solubility of the polymers obtained in Examples 1 and 2 in a solvent was evaluated as follows. 0.5 g of the polymer was added to 10 ml of toluene, and the mixture was stirred at a constant rotation speed, and the time from the start of stirring until the entire polymer was dissolved in toluene was measured. Table 1 shows the results.

[Thin Film Formability Test] The polymer solution obtained in the above solubility test is applied to the surface of a glass substrate by spin coating and dried to form a thin film on the surface of the substrate. Formed and observed. The case where a thin film with a uniform thickness was formed was evaluated as ○, and the case where a thin film with a uniform thickness was not formed was evaluated as x. The results are shown in Table 1.
Shown in

[Charge Transport Performance Test] A 5 cm square glass substrate on which an ITO film was formed was prepared, and the polymer solution obtained in the above solubility test was placed on the surface of the ITO film formed on the glass substrate. After applying by spin coater,
By performing a drying treatment on the obtained coating film, a polymer layer having a thickness of 50 nm was formed. Next, a layer made of a quinolinol aluminum complex is formed on the surface of the polymer layer by a vacuum evaporation method, and a 5 mm square magnesium / silver alloy having a thickness of 100 nm (weight ratio: 10: 1) A film was formed. And IT
Light is emitted by applying a DC voltage between the O film and the magnesium / silver alloy, and the light emission start voltage, 100 cd
/ M ² , a voltage (referred to as “standard voltage” in Table 1) required to obtain a light emission luminance, a light emission efficiency, and a maximum light emission luminance were measured. The results are shown in Table 1.

[0052]

[Table 1]

[0053]

According to the polymer of the present invention, excellent solubility in a solvent can be obtained, and a coating solution for forming a thin film can be easily prepared. A thin film can be easily formed. Therefore, the polymer of the present invention is useful as an electronic material or other resin material. In particular, since the polymer has a tertiary aromatic amine skeleton or a carbazole skeleton in its chemical structure, it has excellent charge transport performance. Is very suitable as a charge transport material. ADVANTAGE OF THE INVENTION According to the manufacturing method of the polymer of this invention, it is excellent in solubility with respect to a solvent, a thin film can be easily formed, and a polymer useful as an electronic material and other resin materials can be manufactured. According to the charge transport material of the present invention, since it contains the above-mentioned polymer, excellent solubility in a solvent is obtained, a thin film can be easily formed, and high charge transport performance is obtained. .

[Brief description of the drawings]

FIG. 1 is a nuclear magnetic resonance spectrum of the epoxide obtained in Synthesis Example 1.

FIG. 2 is a nuclear magnetic resonance spectrum of the epoxide obtained in Synthesis Example 2.

FIG. 3 is a nuclear magnetic resonance spectrum of the polymer obtained in Example 1.

FIG. 4 is a nuclear magnetic resonance spectrum of the polymer obtained in Example 2.

Continued on the front page F-term (reference) 3K007 AA07 AB18 DA02 EB00 FA00 4J005 AA09 BA00 BB01

Claims (7)

[Claims] 1. A polymer comprising a structural unit represented by the following general formula (1). Embedded image [In the general formula (1), R ¹ and R ² each independently represent an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. m is an integer of 0 to 2, and n is an integer of 0 to 3. ] 2. A polymer comprising a structural unit represented by the general formula (1) according to claim 1 and a structural unit represented by the following general formula (2). Embedded image [In the general formula (2), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. p is 0
-3. ] 3. The polymer according to claim 2, wherein the proportion of the structural unit represented by the general formula (1) in all the structural units is 5 mol% or more. 4. The polymer according to claim 1, wherein the weight average molecular weight is 5,000 to 100,000 in terms of polystyrene. 5. A method for producing a polymer, comprising subjecting a compound represented by the following general formula (3) to ring-opening polymerization. Embedded image [In the general formula (3), R ¹ and R ² each independently represent an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. m is an integer of 0 to 2, and n is an integer of 0 to 3. ] 6. A polymer produced by subjecting a compound represented by the general formula (3) according to claim 5 and a compound represented by the following general formula (4) to ring-opening copolymerization. Method. Embedded image [In the general formula (4), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, a monophenylamino group or a diphenylamino group. p is 0
-3. ] 7. A charge transporting material comprising the polymer according to claim 1. Description: