JP5304182B2 - Method for producing polymer compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aromatic diamine-containing polymer compound which has high solvent solubility and exhibits excellent preservability when used as ink and from which an element excellent in a driving voltage, service life when driven and luminescent efficiency can be obtained. <P>SOLUTION: The polymer compound has 3,000-27,000 weight-average molecular weight and has a repeating unit shown by formula (1) (wherein Ar<SP>1</SP>-Ar<SP>5</SP>are each an aromatic hydrocarbon group or a heteroaromatic group each of which can have a substituted group; X is a linking group). <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an aromatic diamine-containing polymer compound and a method for producing the same, a polymer composition containing the polymer compound, an organic electroluminescent device using the polymer compound, and an organic EL display using the organic electroluminescent device It is about.

  The organic electroluminescence device is one of the important factors in its high luminous efficiency. Regarding the luminous efficiency, it consists of a hole transport layer made of an aromatic diamine compound and an aluminum complex of 8-hydroxyquinoline. The organic electroluminescent element provided with the light emitting layer is greatly improved.

  A method for forming the hole transport layer as described above by a wet film forming method has been reported. In general, by forming a layer containing a hole transport material or an electron-accepting compound of an organic electroluminescent device by a wet film forming method, the heat resistance and surface of the device are compared with those formed by a vacuum deposition method. It is said that there are excellent advantages such as improved flatness.

  For example, Patent Document 1 reports that an organic electroluminescent element using an aromatic diamine-containing polymer compound having a high glass transition temperature as a hole transport layer is formed by a wet film forming method. However, the compound used here has a problem that it cannot be dissolved unless it is a polar solvent or a halogen-based solvent having high water solubility.

  In addition, the reason why the driving voltage of the organic electroluminescent element is increased is that the contact between the anode and the hole transport layer is considered to be insufficient. By providing a hole injection layer containing an electron-accepting compound, means for improving the contact between the anode and the hole transport layer and reducing the driving voltage has been studied. As an example, Patent Document 2 discloses a method in which a hole injection layer is formed by a spin coating method, which is a kind of wet film-forming method, using a 1,2-dichloroethane solution containing an aromatic diamine-containing polymer compound. Is described.

  In Patent Document 3, a 1,4-phenylenediamine-containing polymer compound that is a hole transporting material and tris (4-bromophenyl) ammonium hexachloroantimonate (TBPAH) or tris (penta) that are electron accepting compounds. A method is described in which a hole injection / transport layer is formed by spin coating using a solution of fluorophenyl) borane (PPB) dissolved in cyclohexanone or ethyl benzoate.

  When an aromatic diamine-containing polymer compound is used in the hole injection / transport layer as described above, a device having improved heat resistance can be provided. However, the hole injection / transport property of the hole injection / transport layer and the solubility of the aromatic diamine-containing polymer compound suitable for the wet film-forming method in a solvent are considered to be further examined. It was done.

Therefore, in Patent Document 4, the solubility of the aromatic diamine-containing polymer compound in the solvent is improved by reducing specific low-molecular weight components such as cyclic dimers contained in the aromatic diamine-containing polymer compound. It has been proposed to do. However, it is further improved from the viewpoint of stability when storing ink for wet film formation and from preventing unintentional crystal precipitation in the film drying process during wet film formation and ensuring device performance. The required solubility was sought.
JP-A-9-188756 JP 2000-36390 A Japanese Patent Laid-Open No. 2003-213002 JP 2005-209626 A

  The present invention is an aromatic diamine-containing polymer compound having high solvent solubility, excellent storage stability when used as an ink, and an element excellent in driving voltage, driving life, and luminous efficiency when used in the element. It is an object to provide an aromatic diamine-containing polymer compound obtained.

  As a result of intensive studies by the present inventors, it has been found that the following polymer compounds can solve the above problems, and the present invention has been achieved.

That is, the present invention has a weight average molecular weight of 3000 to 27000 by purification using a reprecipitation method using a solvent having a higher hydrophobicity than a rich solvent as a poor solvent , and is represented by the following formula (1 −1 ). a method for producing a polymer to obtain a polymer compound having a repeating unit represented, with ether solvents as the good solvent, the method for producing a polymer which comprises using an alkane-based solvent as a poor solvent , Exist.

（式中、Ａｒ¹¹〜Ａｒ²⁸は、各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ｒ³¹およびＲ³²は、各々独立して、水素原子または置換基を表す。）〕 [In the formula, R ^{1 to} R ⁵ each independently represents a substituent. P and q each independently represent an integer of 0 to ^5. r, s and t each independently represent 0 to 5; Represents an integer of 4. X represents a linking group selected from the following linking group group X ^1. )
<Linking group group X ¹ >

(In the formula, Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ³¹ and R ³² each independently represents a hydrogen atom or a substituent.)]

  Since the polymer compound of the present invention has a relatively small weight average molecular weight, it has high solubility in a solvent and is excellent in ink storage stability. Moreover, the organic electroluminescent element using this polymer compound has a low driving voltage and is excellent in luminous efficiency and driving life.

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. Not specific to the content.

[Polymer compound]
The polymer compound of the present invention has a weight average molecular weight of 3000 to 27000 and has a repeating unit represented by the following formula (1).

（式中、Ａｒ¹¹〜Ａｒ²⁸は、各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ｒ³¹およびＲ³²は、各々独立して、水素原子または置換基を表す。） [In the formula, Ar ^{1 to} Ar ⁵ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. X Represents a linking group selected from the following linking group group X ¹ .
<Linking group group X ¹ >

(In the formula, Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ³¹ and R ³² each independently represents a hydrogen atom or a substituent.)

<Repeating unit represented by formula (1)>
In the formula (1), Ar ^{1 to} Ar ⁵ and Ar ^{11 to} Ar ²⁸ can be applied with any aromatic hydrocarbon group or aromatic heterocyclic group, and each is the same or different. It may have an arbitrary substituent.

Examples of aromatic hydrocarbon groups applicable to Ar ^{1 to} Ar ⁵ and Ar ^{11 to} Ar ²⁸ are benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene. And groups derived from a 6-membered monocyclic ring or a 2-5 condensed ring, such as a ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring.

Moreover, if the aromatic heterocyclic group applied to Ar < ¹ > -Ar < ⁵ > and Ar < ¹¹ > -Ar < ²⁸ > is illustrated, a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, imidazole Ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring , Benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, sinoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, A And groups derived from a 5- or 6-membered monocyclic ring or a 2-4 condensed ring, such as a durene ring.

Ar ^{3 to} Ar ⁵ and Ar ^{11 to} Ar ¹⁵ , Ar ^{17 to} Ar ²⁰ , Ar ^{22 to} Ar ²⁵ , Ar ²⁷ , and Ar ²⁸ are one kind or two or more kinds of aromatic hydrocarbon groups and / or aromatic complexes. A ring group can be connected and used.

A hydrogen atom or an arbitrary substituent can be applied to R ³¹ and R ³² and may be the same or different from each other. Examples of the applicable substituents include alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, silyl groups, siloxy groups, aromatic hydrocarbon groups, aromatic heterocyclic groups, and the like. Examples include those exemplified in the following substituent group Z.

Examples of the substituent that the aromatic hydrocarbon group and the aromatic heterocyclic group in Ar ^{1 to} Ar ⁵ and Ar ^{11 to} Ar ²⁸ may have include one or more of the following substituent group Z. Can be mentioned.

[Substituent group Z]
Preferably an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, such as a methyl group and an ethyl group;
An alkenyl group having preferably 2 to 11 carbon atoms, more preferably 2 to 5 carbon atoms, such as a vinyl group;
An alkynyl group having preferably 2 to 11 carbon atoms, more preferably 2 to 5 carbon atoms, such as an ethynyl group;
A methoxy group, an ethoxy group or the like, preferably an alkoxy group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms;
An aryloxy group having preferably 4 to 25 carbon atoms, more preferably 5 to 14 carbon atoms, such as a phenoxy group, a naphthoxy group, and a pyridyloxy group;
An alkoxycarbonyl group having preferably 2 to 11 carbon atoms, more preferably 2 to 7 carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group;
A dialkylamino group having preferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, such as a dimethylamino group and a diethylamino group;
A diarylamino group having preferably 10 to 30 carbon atoms, more preferably 12 to 22 carbon atoms, such as a diphenylamino group, a ditolylamino group, and an N-carbazolyl group;
An arylalkylamino group having preferably 6 to 25 carbon atoms, more preferably 7 to 17 carbon atoms, such as a phenylmethylamino group;
Preferably an acyl group having 2 to 10 carbon atoms, preferably 2 to 7 carbon atoms, such as an acetyl group and a benzoyl group;
Halogen atoms such as fluorine atoms and chlorine atoms;
A haloalkyl group having preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, such as a trifluoromethyl group;
Preferably an alkylthio group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, such as a methylthio group and an ethylthio group;
A phenylthio group, a naphthylthio group, a pyridylthio group and the like, preferably an arylthio group having 4 to 25 carbon atoms, more preferably 5 to 14 carbon atoms;
A silyl group having preferably 2 to 33 carbon atoms, more preferably 3 to 26 carbon atoms, such as a trimethylsilyl group and a triphenylsilyl group;
Preferably a C2-C33, more preferably C3-C26 siloxy group such as a trimethylsiloxy group, a triphenylsiloxy group;
A cyano group;
An aromatic hydrocarbon group having preferably 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, such as a phenyl group and a naphthyl group;
An aromatic heterocyclic group having preferably 3 to 28 carbon atoms, more preferably 4 to 17 carbon atoms, such as thienyl group and pyridyl group:

  The molecular weight of each of the substituents is preferably 400 or less, more preferably about 250 or less.

Ar ¹ and Ar ² are preferably a group derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of solubility, heat resistance, hole injection / transport properties, and a phenyl group (derived from a benzene ring) Group) and a naphthyl group (derived from a naphthalene ring) are more preferable.
Ar ^{3 to} Ar ⁵ are preferably a group derived from a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring, and a phenylene group (derived from a benzene ring) from the viewpoints of hole injection / transport properties including heat resistance and redox potential. Group), a biphenylene group (a group derived from a benzene ring), and a naphthylene group (a group derived from a naphthalene ring) are more preferable.

  In addition, since the polymer compound of the present invention has very high hole injection / transport properties, the above formula (1) is preferably the following formula (1-1), and the following formula (1-2): More preferably.

(In the formula, R ^{1 to} R ⁵ each independently represents a substituent. P and q each independently represent an integer of 0 to ^5. r, s and t each independently represent 0 to 4) X represents the same meaning as in formula (1).

In the above formula (1-1), specific examples of R ^{1 to} R ⁵ are the examples of the substituent that Ar ^{1 to} Ar ⁵ may have, that is, those exemplified in the substituent group Z. Applicable.

〔式中、Ｙは、下記の連結基群Ｘ²の中から選ばれる連結基を表す。
＜連結基群Ｘ²＞

（式中、Ａｒ¹¹〜Ａｒ¹⁷は、上記のＡｒ¹¹〜Ａｒ¹⁷と同義である。また、好ましい例も同様である。）〕

[Wherein Y represents a linking group selected from the following linking group group X ² .
<Linking group group X ² >

(Wherein, Ar ¹¹ to Ar ¹⁷ are as defined above with respect to the Ar ¹¹ to Ar ^17. Further, preferred examples are also the same.)]

  Specific examples of preferable repeating units of the polymer compound of the present invention are shown below, but the present invention is not limited thereto.

  Among the above specific examples, P-1 to P-11, P-13 to P-18, P-20, P-21, P-23, P-25, preferably in terms of heat resistance and charge transportability. P-26 repeating units, more preferably P-1, P-3, P-4, P-6, P-9, P-10 repeating units, more preferably P-1 to P. -11, P-13 to P-18, P-20, P-21, P-23, P-25, P-26, more preferably P-1, P-3, P- 4, P-6, P-9 and P-10 repeating units, most preferably P-1 and P-4 repeating units.

  The high molecular compound which has a repeating unit represented by Formula (1) may be a compound containing the repeating unit represented by 2 or more types of said Formula (1) as needed. Furthermore, the polymer compound of the present invention may contain other various repeating units as long as the performance is not impaired.

<Weight average molecular weight>
The polymer compound of the present invention has a weight average molecular weight in the range of 3000 to 27000 and is suitable for use in an organic electroluminescence device. If the weight average molecular weight of the polymer compound is smaller than this range, the heat resistance and solvent resistance may be lowered. If the weight average molecular weight is larger than this range, the solvent resistance to the solvent is poor and the ink storage stability is poor. Become.
When the layer containing the polymer compound is formed by a wet film forming method, the weight average molecular weight is particularly preferably about 8000 or more and 25000 or less from the viewpoint of solubility and heat resistance.

  Here, the wet film forming method is a method in which a coating solution in which a material is dissolved or dispersed is applied by a spin coating method, a spray coating method, a dip coating method, a die coating method, a flexographic printing method, a screen printing method, an ink jet method, or the like. It means to form a film.

The weight average molecular weight of the polymer compound of the present invention is measured by SEC (size exclusion chromatography).
The measurement conditions of SEC are as follows.
The column is TSKgel GMH _XL (manufactured by Tosoh Corp.) x 2 or those exhibiting a resolution equal to or higher than that,
Particle size: 9mm
Column size: 7.8 mm inner diameter x 30 cm length x 2 Guaranteed theoretical plate number: about 14000 TP / 30 cm, column temperature is 40 ° C.
The moving bed is selected from tetrahydrofuran and chloroform that do not adsorb to the filler, and the flow rate is 1.0 ml / min. The injection concentration is 0.1% by weight, and the injection amount is 0.10 ml. RI is used as a detector.
The molecular weight distribution is determined by converting the elution time of the sample into the molecular weight using a calibration curve calculated from the elution time of polystyrene (standard sample) having a known molecular weight. In the SEC measurement, the elution time is shorter for the high molecular weight component, and the elution time is longer for the low molecular weight component.

<Glass transition temperature, other physical properties>
The glass transition temperature of the polymer compound of the present invention is usually 90 ° C. or higher, and is preferably 110 ° C. or higher, more preferably 130 ° C. or higher, from the viewpoint of driving stability including the heat resistance of the organic electroluminescent element.
The potential at which the polymer compound of the present invention is oxidized is usually +0.2 to +1.2 V vs. SCE, and preferably +0.4 to +1.0 V vs. SCE from the viewpoint of charge transportability.
The ionization potential of the polymer compound of the present invention is usually 4.5 to 5.5 eV, and preferably 4.8 to 5.3 eV from the viewpoint of charge transportability.

  Since the polymer compound of the present invention has high solubility in various solvents and is excellent in hole injection / transport properties, it can be used as a charge transporting material that can be used in a wet film-forming method. It can be suitably used for an element, a photoelectric conversion element, an organic solar cell, an organic rectifying element, and the like. The polymer compound of the present invention itself can be used as a charge transport material, but can also be used as a charge transport material containing the polymer compound of the present invention and other compounds.

  In addition, since the polymer compound of the present invention is difficult to crystallize, has a high glass transition temperature, and is excellent in thin film formation property, the organic electroluminescent device containing the polymer compound of the present invention has excellent heat resistance and is long. It is possible to provide an organic electroluminescent element that is driven (emitted) stably for a period.

<Low molecular weight component area ratio>
In order to further increase the solubility of the polymer compound of the present invention containing the repeating unit represented by the formula (1) in a solvent, the polymer compound of the present invention is determined by SEC (size exclusion chromatography) measurement. In the molecular weight distribution, the integrated value of the peak corresponding to the molecular weight of the compound represented by the following formula (2) (hereinafter sometimes referred to as “compound (2)”) with respect to the integrated value of the entire molecular weight distribution (hereinafter referred to as “compound (2)”). , “Low molecular weight component area ratio”) is preferably 3% or less, and in terms of solubility, film-forming property, hole injection / transport properties, the low molecular weight component area ratio is further 1.5% or less, In particular, it is preferably 0.7% or less, particularly preferably 0.3% or less, and more preferably 0.001% or more. If the low molecular weight component area ratio is larger than the above upper limit, sufficient solvent solubility cannot be obtained.

（式中、Ａｒ¹〜Ａｒ⁵およびＸは、式（１）におけるものと同義である。また、好ましいものも同様である。）

(In formula, Ar < ¹ > -Ar < ⁵ > and X are synonymous with the thing in Formula (1). Moreover, a preferable thing is also the same.)

  The compound (2) is a cyclic dimer that is usually produced as a by-product in the production process of the polymer compound of the present invention containing the repeating unit represented by the formula (1). Usually, after synthesizing the polymer compound by the synthesis reaction of the polymer compound of the present invention described later, the low molecular weight area ratio before reducing the amount of low molecular weight components such as the cyclic dimer by-produced by purification, 4 to 7%, and depending on conditions, the size may be up to about 15%.

  In addition, the peak corresponding to the molecular weight of the compound (2) means not only the peak indicating the compound (2) but also the peak of the compound appearing at the same position as the compound (2). Examples of the compound in which the peak appears at the same position as the peak of the compound (2) include, in addition to the cyclic dimer represented by the formula (2), a chain dimer in which the cyclic dimer is opened. Also included are cyclic dimers and chain dimers thereof having a structure of formula (2) in which two different types of repeating units represented by formula (1) are linked (that is, a copolymer). .). However, it is usually expected to be a cyclic dimer substantially represented by the formula (2).

  As described above, the polymer compound of the present invention is preferably the case where the formula (1) is the formula (1-1), and more preferably the formula (1-2). The compound (2) is preferably a compound represented by the following formula (2-1), and more preferably a compound represented by the following formula (2-2).

（式中、Ｒ¹〜Ｒ⁵、およびＸ、ｐ、ｑ、ｒ、ｓ、ｔは、式（１−１）におけるものと同義である。また、好ましいものも同様である。）

(In formula, R < ¹ > -R < ⁵ > and X, p, q, r, s, t are synonymous with the thing in Formula (1-1). Moreover, a preferable thing is also the same.)

（式中、Ｙは式（１−２）におけるものと同義である。また、好ましいものも同様である。）

(In formula, Y is synonymous with the thing in Formula (1-2). Moreover, a preferable thing is also the same.)

  The SEC measurement conditions for calculating the low molecular weight component area ratio are the same as the method for measuring the weight average molecular weight.

  In the SEC measurement of the polymer compound of the present invention containing the repeating unit represented by the formula (1), a peak corresponding to the molecular weight of the compound (2) is observed about 18 to 19 minutes from the start of the measurement. After the component corresponding to the molecular weight of the compound (2) is eluted, the refractive index indicated by the detector becomes constant, and the elution time at which the refractive index of the solvent used for the moving bed is almost equal is taken as the peak end. When the elution time at the peak end is converted into a molecular weight, logM is about 2.4 to 2.8.

Here, the low molecular weight component area ratio is the molecular weight distribution determined by the above method, in which the integral value (area A) on the low molecular weight side is doubled from the peak top of the peak corresponding to the molecular weight of the compound (2). It is a value obtained by dividing the value by the integral value (area B) of the entire molecular weight distribution.
That is,
Low molecular weight component area ratio = 2 × (area A) / (area B)
And expressed as a percentage,
Low molecular weight component area ratio (%) = 2 × (area A) / (area B) × 100
It becomes.

  The molecular weight of the compound (2) is calculated according to the repeating unit actually selected from the repeating units represented by the formula (1) contained in the polymer compound. In the molecular weight distribution curve obtained by SEC measurement, a peak corresponding to the molecular weight value is observed. Depending on the polymerization conditions, some of the substituents may react and a slight molecular weight shift may be observed, but even in this case, the molecular weight variation range is about ± 50 or less.

[Method for producing polymer compound]
<Method for Synthesizing Polymer Compound of the Present Invention Containing Repeating Unit Represented by Formula (1)>
The polymer compound of the present invention is obtained by, for example, reacting a dihydroxy compound represented by the following formula (5) with a dihalide represented by the following formula (6) in the presence of a base such as potassium carbonate or triethylamine. Synthesized.

(In the formulas (5), (6) and (1), Ar ^{1 to} Ar ⁵ and X are as defined in the formula (1), and X ′ represents a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom. .)

  In general, by reacting the dihydroxy compound represented by the above formula (5) with the dihalide represented by the above formula (6), the structure has a structure in which the repeating unit represented by the above formula (1) is repeated. Molecular compounds are produced.

  Thus, in synthesizing the polymer compound of the present invention containing the repeating unit represented by the formula (1), a relatively low molecular weight polymer compound having a weight average molecular weight of 3000 to 27000 is prepared. For production, the polymerization reaction is carried out while adjusting the temperature and the reaction time and tracking the progress of the polymerization reaction by SEC measurement. Usually, a polymer compound having a lower molecular weight can be obtained by lowering the polymerization temperature, and a polymer compound having a lower molecular weight can be obtained by reducing the reaction time.

  Furthermore, in order to obtain the polymer compound of the present invention, the following purification is preferably performed.

(1) A method of suspending and washing a crude composition of a polymer compound using a solvent that dissolves the composition to some extent (2) A solvent that easily dissolves the crude composition of the polymer compound, The precipitate and liquid phase produced by dissolving in a rich solvent and adding a solvent that does not dissolve the crude composition to the solution, that is, a poor solvent, or adding the solution of the crude composition to the poor solvent, are filtered or Reprecipitation method of fractionation by operation such as decant (3) After dissolving the polymer compound crude composition in a solvent mixture of rich solvent and poor solvent, the rich solvent is removed by distillation, etc., and the concentration of poor solvent increases (4) A reprecipitation method for separating the precipitate generated along with the liquid phase (4) The crude composition of the polymer compound is dissolved at a high temperature but difficult to dissolve at a low temperature. The temperature of the solution obtained by dissolving at as high a temperature as possible Reprecipitation method for separating the precipitate produced by lowering the degree and the liquid phase The solvent, rich solvent, and poor solvent in the above purification operation may each be one kind or a mixture of a plurality of solvents.

  In particular, the reprecipitation method mainly precipitates a polymer compound by mixing a solution to be purified, that is, a solution in which the polymer compound and components such as impurities are dissolved together with a solvent that serves as a precipitating agent. This is a method of removing the liquid layer before the components such as are deposited. Any solvent can be used as a solvent (rich solvent) for dissolving the product to be purified and a solvent (poor solvent) used as a precipitant, but the solubility of the product to be purified, the shape of the polymer compound to be precipitated, filtration From the viewpoint of operability such as property, the following solvents are preferable. In particular, it is preferable to use a solvent having a higher hydrophobicity than the rich solvent as the poor solvent. Here, the high hydrophobicity means that the polarity is low, and the comparison is made with a partition coefficient between an organic solvent not mixed with water and water. The larger the partition coefficient, the higher the hydrophobicity.

  Examples of the rich solvent include halogen solvents such as chloroform, dichloromethane, 1,2-dichloroethane and chlorobenzene, ether solvents such as tetrahydrofuran, ethylene glycol dimethyl ether and anisole, N, N-dimethylformamide, N, N-dimethylacetamide, N An amide solvent such as methylpyrrolidone, an ester solvent such as γ-butrolactone and methyl benzoate, a ketone solvent such as cyclohexanone and acetophenone, and an aromatic solvent such as benzene, xylene and pyridine are preferable, and a halogen solvent. Chloroform, dichloromethane, 1,2-dichloroethane, ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether are more preferred in terms of operability because the purified product according to the present invention is dissolved in a small amount of solvent. Ku, more preferably tetrahydrofuran.

  On the other hand, as a poor solvent, alcohol solvents such as methanol, ethanol and isopropanol, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as diethyl ether and tert-butyl methyl ether, alkane solvents such as hexane and heptane, Ester solvents such as ethyl acetate and butyl acetate are preferred, and alcohol solvents such as methanol, ethanol, ketone solvents acetone, methyl ethyl ketone, ester solvents ethyl acetate, alkane solvents hexane, and heptane are rich solvents. It is more preferable in terms of operability because it has a higher hydrophobicity and higher purification efficiency and has an appropriate vapor pressure, and hexane and heptane which are alkane solvents are more preferable.

  That is, in the present invention, it is preferable to use an ether solvent and / or an alkane solvent from the viewpoint of the deposition rate and operability of the low molecular weight component, and more preferably, as the rich solvent, the ether solvent and the poor solvent. An alkane solvent is used.

  In the method for producing a polymer compound of the present invention, it is preferable to remove the liquid layer (supernatant liquid) after reprecipitation and before the low molecular weight component is precipitated. Specifically, from the point of mixing a solution in which at least a high molecular compound and a low molecular weight component, which is a product to be purified, and a poor solvent as a precipitant are mixed to form a mixture, that is, a solution is spread. The liquid layer is preferably removed within 60 minutes after the addition is completed, more preferably within 45 minutes, and further preferably within 30 minutes after 1 minute.

[Polymer composition]
The polymer composition of the present invention is characterized by containing the polymer compound of the present invention and an electron accepting compound described later, and is preferably used for an organic electroluminescence device. The polymer composition of the present invention further contains a solvent, and is preferably used for wet film formation as a composition in which the polymer compound or electron accepting compound of the present invention is dissolved or dispersed in a solvent.

  In addition, in the polymer composition of this invention, only 1 type of the high molecular compound of this invention may be contained, and 2 or more types may be contained. Moreover, as long as the effect of this invention is not impaired, you may contain high molecular compounds other than the compound of this invention mentioned above. Similarly, only one type of electron-accepting compound may be included, or two or more types may be included. Moreover, the polymer composition of the present invention may further contain one or more hole transport materials described later.

<Electron-accepting compound>
The electron accepting compound used in the polymer composition of the present invention is preferably a compound having an oxidizing power and the ability to accept one electron from the polymer compound of the present invention. Examples of the electron-accepting compound include, for example, an onium salt substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate; iron (III) chloride (Japanese Patent Laid-Open No. 11-251067) Publication), high valence inorganic compounds such as ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris (pentafluorophenyl) borane (JP-A-2003-31365); fullerene derivatives; halogens A compound selected from the group consisting of metal halides, Lewis acids, organic acids, salts of arylamines and metal halides, salts of arylamines and Lewis acids, and the like.

  Examples of the onium salt include those described in WO 2005/089024 pamphlet, and preferred examples thereof are also the same, and particularly preferred is a compound represented by the following formula (3).

  Examples of the aromatic boron compound include a boron compound represented by the following formula (7). The boron compound represented by the formula (7) is preferably a Lewis acid. The electron affinity of the boron compound is usually 4 eV or more, preferably 5 eV or more.

In the formula (7), preferably, Ar ^{7 to} Ar ⁹ are each independently a monocyclic 5- or 6-membered ring such as a phenyl group, a naphthyl group, an anthryl group, or a biphenyl group that may have a substituent, or An aromatic hydrocarbon group formed by condensing 2 to 3 of these and / or directly bonding; or a 5- or 6-membered ring such as a thienyl group, pyridyl group, triazyl group, pyrazyl group, quinoxalyl group, etc., which may have a substituent Or an aromatic heterocyclic group formed by condensing 2 or 3 thereof and / or directly bonding them.

Examples of the substituent that the aromatic hydrocarbon group and aromatic heterocyclic group of Ar ^{7 to} Ar ⁹ may have include, for example, a halogen atom such as a fluorine atom; and a C 1-6 such as a methyl group and an ethyl group. A linear or branched alkyl group such as a vinyl group; an alkenyl group such as a vinyl group; a linear or branched alkoxycarbonyl group having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group; a carbon number of 1 such as a methoxy group or an ethoxy group -6 linear or branched alkoxy group; aryloxy group such as phenoxy group and benzyloxy group; dialkylamino group such as dimethylamino group and diethylamino group; acyl group such as acetyl group; haloalkyl group such as trifluoromethyl group And a cyano group.

Aromatic hydrocarbon group and aromatic heterocyclic group may substituent of the Ar ⁷ to Ar ^9, at least one of Ar ⁷ to Ar ^9, Hammett constants (.sigma.m and / or .sigma.p) positive It is preferable that it is a substituent that exhibits a value, and Ar ^{7 to} Ar ⁹ are all substituents that have a positive Hammett constant (σm and / or σp). It is particularly preferred to have By having such an electron-withdrawing substituent, the electron-accepting property of the compound represented by the formula (7) is improved. In particular, Ar ^{7 to} Ar ⁹ are more preferably an aromatic hydrocarbon group or an aromatic heterocyclic group substituted with a halogen atom.

  Preferred specific examples (1-29) of the boron compound represented by the formula (7) are shown below, but are not limited thereto.

  Among these, the following compounds are preferable.

  Specific examples of compounds selected from the group consisting of metal halides, Lewis acids, organic acids, salts of arylamines and metal halides, and salts of arylamines and Lewis acids include the following compounds.

  Among these various compounds, the electron-accepting compound used in the polymer composition of the present invention is particularly preferably a compound represented by the above formula (3) from the viewpoint of electron-accepting property, heat resistance, and solubility.

  In the polymer composition of the present invention, the content ratio of the electron-accepting compound to the polymer compound of the present invention is usually 0.1% by weight or more, preferably 1% by weight or more. Moreover, it is 100 weight% or less normally, Preferably it is 40 weight% or less. If the amount of the electron-accepting compound is larger than this range, the film formability is lowered, and if it is less, the hole-injecting property tends to be lowered.

<Solvent>
The solvent is preferably a solvent that dissolves the polymer compound of the present invention in an amount of usually 0.05% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more. In addition, it is preferable to dissolve 0.005% by weight or more of the electron-accepting compound, more preferably 0.05% by weight or more, and even more preferably 0.5% by weight or more.

  Specific examples of the solvent include ether solvents and ester solvents. More specifically, examples of ether solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1, Examples include aromatic ethers such as 3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenylether. Examples of the ester solvent include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, ethyl benzoate, benzoic acid And aromatic esters such as propyl and n-butyl benzoate. These may be used alone or as a mixed solvent of two or more.

  The concentration of these solvents in the composition is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more. In addition to the solvents described above, various other solvents may be included as necessary as the solvent. Examples of such other solvents include aromatic hydrocarbon solvents such as benzene, toluene and xylene, amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide. . Moreover, various additives, such as a leveling agent and an antifoamer, may be included.

  As a solvent, it has a high ability to dissolve cation radicals of a hole injecting / transporting material generated from a mixture of a hole transporting material and an electron accepting compound, such as an electron accepting compound and a polymer compound of the present invention. Is preferably mixed with an ether solvent and an ester solvent.

  Examples of the deactivating substance that deactivates the cation radical or the solvent that generates such deactivating substance include alcohol solvents such as ethyl alcohol; aldehyde solvents such as benzaldehyde; α such as methyl ethyl ketone, cyclohexanone, and acetophenone. Examples include ketone solvents having a hydrogen atom at the -position.

  In addition, a hole-transporting material such as the polymer compound of the present invention, an electron-accepting compound, a deactivating substance that deactivates a cation radical of the hole-transporting material resulting from a mixture thereof, or such a deactivating substance is generated. Examples of the compound to be made include a protonic acid and a halogen-based solvent. Specifically, examples of the protonic acid include inorganic acids such as hydrochloric acid and hydrobromic acid; and organic acids such as formic acid, acetic acid, and lactic acid. Examples of the halogen-based solvent include a chlorine solvent, a bromine-containing solvent, and an iodine-containing solvent.

  When a layer is formed by a wet film-forming method using the polymer composition of the present invention, if an organic acid or a halogen-based solvent is contained in the polymer composition solution of the present invention, the following may occur. Yes, not preferred. For example, an organic acid reacts with a hole injecting / transporting site and transforms into an ammonium salt, so that the hole injecting / transporting property of the obtained layer is lowered. In addition, when a halogen-based solvent is contained, these halogen-based solvents often contain a corresponding acid, and this acid, like the above-mentioned organic acid, is used for hole injection / transport. In order to change the property site, the hole injection / transport property of the obtained layer is also lowered. In addition, it is not preferable that halides are mixed even in terms of a large environmental load.

In addition, since an organic electroluminescent element is formed by laminating a plurality of layers made of organic compounds, each layer is required to be a uniform layer. When a layer is formed by a wet film forming method, moisture is mixed into the coating solution (composition) for forming the layer, so that moisture is mixed into the coating film and the uniformity of the film is impaired. Is preferably as small as possible.
Specifically, the amount of water contained in the polymer composition of the present invention is 1% by weight or less, preferably 0.1% by weight or less, more preferably 0.05% by weight or less.

  In general, since organic electroluminescent elements use many materials such as cathodes that deteriorate significantly due to moisture, the presence of moisture is not preferable from the viewpoint of element degradation. Examples of the method for reducing the amount of water in the composition include nitrogen gas sealing, use of a desiccant, dehydration of the solvent in advance, use of a solvent with low water solubility, and the like. In particular, it is preferable to use a solvent having low water solubility because the solution coating film can prevent whitening by absorbing moisture in the air during the coating process.

  From such a viewpoint, the polymer composition of the present invention contains, for example, a solvent having a water solubility at 25 ° C. of 1% by weight or less, preferably 0.1% by weight or less, in the composition of 10% by weight or more. It is preferable to contain. The solvent satisfying the solubility condition is more preferably 30% by weight or more, and particularly preferably 50% by weight or more.

<Hole transport material>
The polymer composition of the present invention may further contain a hole transport material.
As the hole transporting material, a compound having an ionization potential of 4.5 eV to 5.5 eV is preferable in terms of charge transporting properties. For example, aromatic amine compounds, phthalocyanine derivatives or porphyrin derivatives, 8-hydroxy having a diarylamino group. Examples include metal complexes of quinoline derivatives and oligothiophene derivatives.

  For example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (JP 59-194393 A); 4,4′- An aromatic amine containing two or more tertiary amines typified by bis [N- (1-naphthyl) -N-phenylamino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms No. 234681); an aromatic triamine having a starburst structure as a derivative of triphenylbenzene (US Pat. No. 4,923,774); N, N′-diphenyl-N, N′-bis (3-methylphenyl) ) Aromatic diamines such as biphenyl-4,4′-diamine (US Pat. No. 4,764,625); α, α, α ′, α′-tetramethyl-α, α′-bis (4-di-) p- Rilaminophenyl) -p-xylene (Japanese Patent Laid-Open No. 3-269084); sterically asymmetric triphenylamine derivative as a whole molecule (Japanese Patent Laid-Open No. 4-129271); a plurality of aromatic diamino groups in the pyrenyl group Substituted compounds (JP-A-4-175395); aromatic diamines in which tertiary aromatic amine units are linked by an ethylene group (JP-A-4-264189); aromatic diamines having a styryl structure (JP-A-4-4-1395) No. 290851); an aromatic tertiary amine unit linked by a thiophene group (JP-A-4-304466); a starburst aromatic triamine (JP-A-4-308688); 4-364153); a tertiary amine linked by a fluorene group (JP-A-5-25) No. 73); Triamine compounds (JP-A-5-239455); Bisdipyridylaminobiphenyl (JP-A-5-320634); N, N, N-triphenylamine derivatives (JP-A-6-1972) An aromatic diamine having a phenoxazine structure (JP-A-7-138562); a diaminophenylphenanthridine derivative (JP-A-7-252474); a hydrazone compound (JP-A-2-311591); a silazane compound ( U.S. Pat. No. 4,950,950); silanamine derivatives (JP-A-6-49079); phosphamine derivatives (JP-A-6-25659); quinacridone compounds and the like. Among these compounds, one kind or two or more kinds as necessary may be mixed with the compound of the present invention.

  Preferable specific examples of the phthalocyanine derivative or porphyrin derivative that may be used in the polymer composition of the present invention include, for example, porphyrin, 5,10,15,20-tetraphenyl-21H, 23H-porphyrin, 5,10 , 15,20-tetraphenyl-21H, 23H-porphyrin cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin copper (II), 5,10,15,20-tetraphenyl- 21H, 23H-porphyrin zinc (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl) -21H, 23H -Porphyrin 29H, 31H-phthalocyanine copper (II) phthalocyanine Zinc (II) phthalocyanine titanium phthalocyanine oxide magnesium phthalocyanine lead phthalocyanine copper (II), 4,4 ', 4' ', 4' '' - tetraaza-29H, 31H-phthalocyanine, and the like.

  The metal complex of the 8-hydroxyquinoline derivative having a diarylamino group that may be used in the polymer composition of the present invention is an alkali metal, alkaline earth metal, Sc, Y, V, Cr, Mn , Fe, Co, Ni, Cu, Zn, Cd, Al, Ga, In, Si, Ge, Sn, Sm, Eu, Tb, and the ligand 8-hydroxyquinoline is a diarylamino group One or more as substituents, but may have any substituent other than the diarylamino group.

  In addition, examples of the oligothiophene derivative used as a hole transport material that may be used by mixing with the polymer composition of the present invention include α-sexithiophene.

  The molecular weight of these hole transport materials is usually less than 2000, preferably less than 1800, more preferably less than 1200, but usually 500 or more, preferably 700 or more.

  When the polymer composition of the present invention contains a hole transport material, the content ratio of the hole transport material to the polymer compound of the present invention is usually 5% by weight or more, preferably 10% by weight or more. Moreover, it is 95 weight% or less normally, Preferably it is 80 weight% or less. When the amount of the hole transport material is larger than this range, the film quality of the obtained film may be fragile, and when it is less, the voltage may increase or the smoothness of the film may be poor.

[Organic electroluminescence device]
The organic electroluminescence device of the present invention is characterized by having a layer containing the polymer compound of the present invention or a layer formed using the polymer composition of the present invention.

Hereinafter, the structure of the organic electroluminescent element of the present invention will be described.
The organic electroluminescent element of the present invention comprises a first electrode, a layer formed using the polymer compound of the present invention or the polymer composition of the present invention, and a second electrode in this order. . The organic electroluminescent element according to the present invention may have only one layer between the first electrode and the second electrode, or may have two or more layers. The layer between the first electrode and the second electrode may be formed by a wet film formation method or a vacuum evaporation method.

  Examples of layers between the first electrode and the second electrode include a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, an electron blocking layer, etc. Layer. The layer formed using the polymer compound of the present invention or the polymer composition of the present invention is usually used as a hole injection layer, but may be other layers.

  The organic electroluminescent element of the present invention usually comprises a substrate, has a laminated structure in which the first electrode is formed on the substrate, and the above-described layers are laminated thereon. Here, one of the first electrode and the second electrode is an anode, and the other is a cathode. Hereinafter, the case where the first electrode is an anode and the second electrode is a cathode will be described in the order of stacking from the substrate side.

  FIG. 1 is a cross-sectional view schematically showing an example of the structure of the organic electroluminescent element of the present invention. The organic electroluminescent device shown in FIG. 1 includes an anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, a hole blocking layer 6, an electron transport layer 7, and an electron injection layer 8 on a substrate 1. And the cathode 9 are laminated in this order.

(substrate)
The substrate 1 serves as a support for the organic electroluminescent element, and a quartz or glass plate, a metal plate or a metal foil, a plastic film, a sheet, or the like is used. In particular, it is preferable to use a transparent substrate made of a general-purpose material such as a glass plate, a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone.

  Examples of the material of the substrate 1 include various shot glasses such as BK7, SF11, LaSFN9, BaK1, and F2, synthetic phased silica glass, optical crown glass, low expansion borosilicate glass, sapphire glass, soda glass, and alkali-free glass. Glass, TFT-formed glass, and polymer materials include acrylic resins such as polymethylmethacrylate and cross-linked acrylate, aromatic polycarbonate resins such as bisphenol A polycarbonate, polyester resins such as polyethylene terephthalate, and polycycloolefins. Examples thereof include crystalline polyolefin resins, epoxy resins, styrene resins such as polystyrene, polysulfone resins such as polyethersulfone, and synthetic resins such as polyetherimide resin. Moreover, 2 or more types of laminated bodies may be sufficient among these. Depending on the purpose and application, an optical film such as an antireflection film, a circularly polarizing film, or a retardation film may be formed on or bonded to these substrates.

  However, it is preferable to pay attention to gas barrier properties when using a synthetic resin substrate. This is because if the gas barrier property of the substrate 1 is too small, the organic electroluminescence element may be deteriorated by the outside air that has passed through the substrate 1. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

(anode)
An anode 2 is provided on the substrate 1. The anode 2 plays a role of injecting holes into a layer (such as the hole injection layer 3 or the light emitting layer 5) on the light emitting layer 5 side.

  The anode 2 is usually made of a metal such as aluminum, gold, silver, nickel, palladium, or platinum; a metal oxide such as an oxide of indium and / or tin; a metal halide such as copper iodide; a carbon black or a poly It is composed of conductive polymers such as (3-methylthiophene), polypyrrole and polyaniline. In addition, only 1 type may be used for the material of the anode 2, and 2 or more types may be used together by arbitrary combinations and a ratio.

Although there is no restriction | limiting in the formation method of the anode 2, Usually, it carries out by sputtering method, a vapor deposition method, etc. In addition, when forming the anode 2 using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, and conductive polymer fine powder, an appropriate binder resin solution is used. The anode 2 can also be formed by dispersing them and applying them onto the substrate 1. Furthermore, in the case of a conductive polymer, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 (Appl. Phys. Lett. 60, 2711, 1992).
In addition, the anode 2 is usually a single layer structure, but may be a laminated structure made of a plurality of materials if desired.

  The thickness of the anode 2 varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more. Also, it is usually 1000 nm or less, preferably 500 nm or less. On the other hand, when the anode 2 may be opaque, the thickness of the anode 2 is arbitrary, and the anode 2 may be the same as the substrate 1. Further, it is possible to laminate different conductive materials on the anode 2.

Further, for the purpose of removing impurities adhering to the anode 2 and adjusting the ionization potential to improve the hole injection property, the surface of the anode 2 is subjected to ultraviolet (UV) / ozone treatment, oxygen plasma, argon plasma. It is preferable to process.
Furthermore, a known anode buffer layer is inserted between the hole injection layer 3 and the anode 2 for the purpose of further improving the efficiency of hole injection and improving the adhesion of the whole organic layer to the anode. Also good.

(Hole injection layer)
The hole injection layer 3 is a layer that transports holes from the anode 2 to the light emitting layer 5. The hole injection layer 3 is preferably a layer containing the polymer compound of the present invention, and more preferably a layer containing an electron accepting compound. Moreover, it is preferable that it is a layer formed using the polymer composition of this invention. In particular, the hole injection layer 3 is a layer formed by a wet film formation method using the polymer composition of the present invention containing a solvent (hereinafter sometimes referred to as “coating composition”). It is preferable.

  The method for forming the hole injection layer 3 is not limited as long as the effect of the present invention is not significantly impaired as long as patterning is possible. For example, spin coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method, spray coating method, capillary coating method, ink jet method, screen printing method, gravure printing method, flexographic printing method, etc. Can be mentioned. Among these film forming methods, a spin coating method, a spray coating method, and an ink jet method are preferable. This is because the liquid property specific to the coating composition used in the organic electroluminescence device is matched.

  The film formation temperature is not limited as long as the effects of the present invention are not significantly impaired, but is preferably 10 ° C or higher, more preferably 13 ° C or higher, further preferably 16 ° C or higher, preferably 50 ° C or lower, and 40 ° C or lower. More preferably, it is 30 ° C. or less. This is to suppress the formation of crystals in the coating composition.

  The relative humidity in the film forming step is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.01 ppm or more, preferably 0.05 ppm or more, more preferably 0.1 ppm or more, and usually 80% or less, preferably Is 60% or less, more preferably 15% or less, still more preferably 1% or less, and particularly preferably 100 ppm or less. If the relative humidity is too small, it may be difficult to control film forming conditions in the wet film forming method. On the other hand, if it is too large, moisture adsorption on the organic layer may be easily affected.

  The volume concentration of oxygen in the film forming step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 0.01 ppm or more, more preferably 0.05 ppm or more, and preferably 50% or less, more preferably 25. % Or less, more preferably 1% or less, particularly preferably 100 ppm or less, particularly preferably 10 ppm or less. An environment in which the oxygen concentration is too low is difficult to control. If the oxygen concentration is too high, oxygen diffuses inside the organic layer, which may adversely affect device characteristics.

The number of fine particles (that is, the number of particles) in the film forming environment is not limited as long as the effect of the present invention is not significantly impaired. From the viewpoint of reducing dark spots, particles having a particle size of 0.5 μm or more are usually per 1 m ^3. It is 10,000 or less, preferably 5000 or less. Particularly preferably, the number of particles having a particle diameter of 0.3 μm or more is 5000 or less per 1 m ³ . Although there is no restriction | limiting in a lower limit, from a viewpoint of industrial practicality, it can be considered that normally 100 particles with a particle size of 0.3 μm or more exist per 1 m ³ . If the number of particles is too large, dark spots may occur, and environmental control tends to become more difficult as it falls below the above range.
The number of fine particles is detected by a light scattering method, and can be detected by, for example, a handheld particle counter KR (manufactured by Lion Co., Ltd.).

The film thickness of the layer formed in the film forming step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, and preferably 30 μm or less. More preferably, it is 20 micrometers or less, More preferably, it is 15 micrometers or less. This is because high film thickness accuracy can be obtained within this range.
The film thickness accuracy is defined as the ratio between the maximum value and the minimum value of the film thickness of the light emitting portion (the organic layer portion sandwiched between the anode and the cathode). The film thickness accuracy is measured with a contact film thickness meter or an interference film thickness meter.

A layer formed by a wet film formation method is dried by performing a drying process after the film formation process.
The drying temperature in the drying step is not limited as long as the effects of the present invention are not significantly impaired, but when heat treatment is performed, it is usually 50 ° C. or higher, preferably 80 ° C. or higher, and usually 300 ° C. or lower, preferably 250 ° C. or lower. . If the temperature is too high, the other layers may be adversely affected. If the temperature is too low, the solvent may remain in the layers. The drying temperature refers to, for example, the plate temperature in the case of the hot plate method, and the ambient temperature in the vicinity of the organic layer in the case of the method using a heater.

  The drying time in the drying step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 30 seconds or more, more preferably 1 minute or more, further preferably 2 minutes or more, and preferably 5 hours or less, more preferably Is 2 hours or less, more preferably 1 hour or less. If the drying time is too long, the components of the other layers tend to diffuse, and if too short, the layers tend to be inhomogeneous.

  The relative humidity in the drying step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 1% or more, more preferably 5% or more, further preferably 10% or more, and preferably 80% or less, more preferably. Is 50% or less, more preferably 20% or less. If the relative humidity is too high, moisture tends to remain in the layer.

  The film thickness of the layer after the drying step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, and preferably 300 nm or less, more preferably Is 200 nm or less, more preferably 150 nm or less. If the film thickness is too small, defects may occur in the specific organic layer. In addition, if the film thickness is too large, the influence of element characteristics may increase due to film thickness unevenness.

(Hole transport layer)
Examples of the material for forming the hole transport layer 4 include the same compounds as those exemplified as the hole transport material that may be used by mixing with the polymer composition of the present invention. In addition, for example, polymer materials such as polyarylene ether sulfone containing polyvinyl carbazole, polyvinyl triphenylamine, and tetraphenylbenzidine can be used. In addition, the material of the positive hole transport layer 4 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The hole transport layer 4 may be a film obtained by forming a triarylamine derivative having a crosslinkable group, a fluorene derivative, or the like by a wet film forming method and performing cross-linking polymerization with heat or light. Good.

  The thickness of the hole transport layer 4 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 10 nm or more, preferably 30 nm or more, and usually 300 nm or less, preferably 100 nm or less.

(Light emitting layer)
A light emitting layer 5 is usually provided on the hole transport layer 4. The light-emitting layer 5 includes holes injected from the anode 2 through the hole injection layer 3 and the hole transport layer 4 between the electrodes to which an electric field is applied, and from the cathode 9 through the electron injection layer 8 and the hole blocking layer 6. It is a layer that is excited by recombination with injected electrons and serves as a main light emitting source.

  The organic light emitting layer 5 contains at least a material having a light emitting property (light emitting material), and preferably has a material having a hole transporting property (hole transporting compound) or an electron transporting property. Material (electron transporting compound). Furthermore, the organic light emitting layer 5 may contain other components without departing from the spirit of the present invention. As these materials, from the viewpoint of forming the organic light emitting layer 5 by a wet film formation method as described later, it is preferable to use any low molecular weight materials.

  Any known material can be applied as the light emitting material. For example, a fluorescent material or a phosphorescent material may be used, but a phosphorescent material is preferable from the viewpoint of internal quantum efficiency. Further, for example, when an RGB element is manufactured, phosphorescent materials may be used for R and G, and fluorescent materials may be used for B.

  For the purpose of improving the solubility in a solvent, it is also important to reduce the symmetry and rigidity of the molecules of the luminescent material, or to introduce a lipophilic substituent such as an alkyl group.

  Examples of fluorescent dyes that emit blue light include perylene, pyrene, anthracene, chrysene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof. Examples of the green fluorescent dye include quinacridone derivatives and coumarin derivatives. Examples of yellow fluorescent dyes include rubrene and perimidone derivatives. Red fluorescent dyes include DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothio Xanthene and the like.

  As the phosphorescent material, for example, a long-period type periodic table (hereinafter referred to as a long-period type periodic table when referred to as “periodic table” unless otherwise specified) is selected from the seventh to eleventh groups. And an organometallic complex containing a metal. Preferred examples of the metal selected from Groups 7 to 11 of the periodic table contained in the phosphorescent organometallic complex include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

  Specific examples of the phosphorescent organometallic complex include the following compounds, but are not limited thereto.

In the present invention, the molecular weight of the compound used as the light emitting material is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, preferably 200 or more, more preferably 300 or more. More preferably, the range is 400 or more.
In addition, the light emitting layer 5 may contain any 1 type among the various light emitting materials demonstrated above, and may have 2 or more types together by arbitrary combinations and ratios.

  Examples of the low molecular weight hole transporting compound include various compounds exemplified as the hole transporting compound of the hole transporting layer, and 4,4′-bis [N- (1-naphthyl)- N-phenylamino] biphenyl, an aromatic diamine containing two or more tertiary amines and having two or more condensed aromatic rings substituted with nitrogen atoms (Japanese Patent Laid-Open No. 5-234811), 4,4 An aromatic amine compound having a starburst structure such as', 4 "-tris (1-naphthylphenylamino) triphenylamine (Journal of Luminescence, 1997, Vol.72-74, pp.985), Spiro compounds such as aromatic amine compounds comprising tetramers (Chemical Communications, 1996, pp. 2175), 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synthetic Metals, 1 997, Vol.91, pp.209).

  Examples of low molecular weight electron transport compounds include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND) and 2,5-bis (6 ′-(2 ′). , 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ( BCP, bathocuproine), 2- (4-biphenylyl) -5- (p-tertiarybutylphenyl) -1,3,4-oxadiazole (tBu-PBD), 4,4′-bis (9-carbazole) ) -Biphenyl (CBP) and the like.

  The thickness of the light emitting layer 5 is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less.

(Hole blocking layer)
A hole blocking layer 6 may be provided on the cathode side of the light emitting layer 5. The hole blocking layer 6 is a layer laminated on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 9 side. The hole blocking layer 6 has a role of blocking holes moving from the anode 2 from reaching the cathode 9 and a role of efficiently transporting electrons injected from the cathode 9 toward the light emitting layer 5. Have

  The physical properties required for the material constituting the hole blocking layer 6 include high electron mobility, low hole mobility, a large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). Is high. Examples of the material of the hole blocking layer 6 satisfying such conditions include, for example, bis (2-methyl-8-quinolinolato), (phenolato) aluminum, bis (2-methyl-8-quinolinolato), (triphenylsilanolato). ) Mixed ligand complexes such as aluminum, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, distyrylbiphenyl Derivatives such as styryl compounds (JP-A-11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole and other triazole derivatives ( JP-A-7-41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), etc. It is below. Further, a compound having at least one pyridine ring substituted at the 2,4,6-position described in International Publication No. 2005-022962 is also preferable as the material for the hole blocking layer 6. In addition, the material of the hole-blocking layer 6 may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

  There is no restriction | limiting in the formation method of the hole-blocking layer 6. FIG. Therefore, the above-described material can be formed by the method described as the method for forming the above-described hole injection layer 3 or other methods.

  The thickness of the hole blocking layer 6 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

(Electron transport layer)
The electron transport layer 7 is provided for the purpose of further improving the light emission efficiency of the device, and efficiently transports electrons injected from the cathode 9 between the electrodes to which an electric field is applied in the direction of the light emitting layer 5. Formed from a compound capable of

  As an electron transport compound used for the electron transport layer 7, usually, the electron injection efficiency from the cathode 9 or the electron injection layer 8 is high, and the injected electrons are transported efficiently with high electron mobility. The compound which can be used is used. Examples of the compound satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives , Distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compounds ( JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type zinc Such as emissions of zinc, and the like. In addition, the material of the electron carrying layer 7 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

There is no restriction | limiting in the formation method of the electron carrying layer 7. FIG.
The thickness of the electron transport layer 7 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

(Electron injection layer)
The electron injection layer 8 plays a role of efficiently injecting electrons injected from the cathode 9 into the light emitting layer 5. In order to perform electron injection efficiently, the material for forming the electron injection layer 8 is preferably a metal having a low work function. Examples thereof include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like.

  Further, the thickness of the electron injection layer 8 is usually preferably 0.1 nm or more and 5 nm or less. Furthermore, organic compounds represented by metal complexes such as nitrogen-containing heterocyclic compounds such as bathophenanthroline and aluminum complexes of 8-hydroxyquinoline. Doping an electron transport compound with an alkali metal such as sodium, potassium, cesium, lithium or rubidium (described in JP-A-10-270171, JP-A 2002-1000047, JP-A 2002-1000048, etc.) Therefore, it is preferable because the electron injecting / transporting property is improved and excellent film quality can be achieved. In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

In addition, the material of the electron injection layer 8 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of the electron injection layer 8. FIG.

(cathode)
The cathode 9 plays a role of injecting electrons into a layer (such as the electron injection layer 8 or the light emitting layer 5) on the light emitting layer 5 side.

  As the material of the cathode 9, the material used for the anode 2 can be used. However, in order to perform electron injection efficiently, a metal having a low work function is preferable. For example, tin, magnesium, indium, A suitable metal such as calcium, aluminum, silver, or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy. In addition, the material of the cathode 9 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The film thickness of the cathode 9 is usually the same as that of the anode 2.

  For the purpose of protecting the cathode 9 made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, for example, metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used. In addition, these materials may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

At the interface between the cathode 9 and the light emitting layer 5 or the electron transport layer 7, for example, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (II) (CsCO ₃ ), etc. It is also an effective method to improve the efficiency of the element (Applied Physics Letters, 1997, Vol. 70, pp. 152; 10-74586; IEEE Transactions on Electron Devices, 1997, Vol. 44, pp. 1245; SID 04 Digest, pp. 154, etc.).

  Moreover, in the layer structure demonstrated above, it has arbitrary layers other than the layer shown in FIG. 1 between the anode 2 and the cathode 9, and the light emitting layer 5 in an organic electroluminescent element, unless the performance is impaired. Alternatively, any layer other than the light emitting layer 5 may be omitted. For example, the electron transport layer 7 and the hole blocking layer 6 may be appropriately provided as necessary. 1) Only the electron transport layer, 2) Only the hole blocking layer, and 3) The hole blocking layer / electron transport layer There are usages such as stacking, 4) not using, etc. For example, as shown in FIG. 2, the layer between the light emitting layer 5 and the cathode 9 can be omitted.

Moreover, it is also possible to laminate components other than the substrate in the reverse order. For example, other components on the substrate 1 are the cathode 9, the electron injection layer 8, the electron transport layer 7, the hole blocking layer 6, the light emitting layer 5, the hole transport layer 4, the hole injection layer 3, and the anode 2 in this order. It may be provided.
Furthermore, the organic electroluminescent element of the present invention can be configured by laminating components other than the substrate between two substrates, at least one of which is transparent.

In addition, a structure in which a plurality of components (light emitting units) other than the substrate are stacked in a plurality of layers (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interface layer between the steps (between the light emitting units) (when the anode is ITO and the cathode is Al, these two layers), for example, a charge made of vanadium pentoxide (V ₂ O ₅ ) or the like. When a generation layer (Carrier Generation Layer: CGL) is provided, a barrier between steps is reduced, which is more preferable from the viewpoint of light emission efficiency and driving voltage.

  Furthermore, the organic electroluminescent device of the present invention may be configured as a single organic electroluminescent device, or may be applied to a configuration in which a plurality of organic electroluminescent devices are arranged in an array, and an anode and a cathode May be applied to a configuration in which are arranged in an XY matrix.

  Each layer described above may contain components other than those described as materials unless the effects of the present invention are significantly impaired.

[Organic EL display]
The organic EL display of the present invention uses the organic electroluminescent element of the present invention as described above. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display of the present invention is formed by a method as described in “Organic EL Display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). can do.

  Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.

[Production of polymer compounds]
<Example 1>
(Synthesis of Polymer Compound “Precision Composition 1” Containing Exemplary Repeating Unit (P-1) and Weight Average Molecular Weight (Mw) = 24,000

  N, N′-bis (4-hydroxyphenyl) -N, N′-diphenyl-p-phenylenediamine (1.00 parts by weight) and 4,4′-difluorobenzophenone (0.49 parts by weight) under a nitrogen stream , Potassium carbonate (1.87 parts by weight), and 1-methyl-2-pyrrolidone (23.13 parts by weight) were stirred at 131 ° C. for 9 hours. After cooling the obtained reaction mixture, the filtrate from which insolubles were removed by intermediate filtration was added to methanol to obtain a precipitate. This was collected by filtration and dried under reduced pressure at 60 ° C. for 6 hours to obtain a crude composition 1-1.

  The crude composition 1-1 was dissolved in tetrahydrofuran, and normanheptane was added to the solution, followed by stirring at 20 ± 5 ° C. for 30 minutes to obtain a precipitate. The supernatant was removed by decantation to obtain a precipitate. Further, the same reprecipitation operation was repeated to obtain a crude composition 1-2.

  The crude composition 1-2 was dissolved in toluene, 2-propanol and demineralized water were added to the toluene solution, and the mixture was stirred at 50 ± 5 ° C. for 30 minutes. The organic layer obtained by liquid separation after standing was further washed twice by the same operation to remove inorganic components. The obtained organic layer was concentrated under reduced pressure, the residue was extracted with tetrahydrofuran, this solution was added to methanol for precipitation, and then collected by filtration and dried under reduced pressure at 60 ° C. for 8 hours. .81 parts by weight, yield 59%).

(SEC measurement of fine composition 1)
SEC (Size Exclusion Chromatography) measurement of the obtained polymer compound (Precision Composition 1) was performed under the following conditions to measure the molecular weight.
<SEC measurement conditions>
Apparatus: HLC8020 manufactured by Tosoh Corporation
Column: Tosoh TSKgel GMH _XL (column size 30cm x 2)
Column temperature: 40 ° C
Moving bed: Tetrahydrofuran Flow rate: 1.0 ml / min Injection concentration: 0.1% by weight
Injection volume: 0.10ml
Detector: RI
Conversion method: Polystyrene conversion Approximation formula: Tertiary formula

  The weight average molecular weight (Mw) of the obtained polymer compound (Fine Composition 1) was 24,000.

(Measurement of solubility of fine composition 1)
This polymeric compound had a more improved solubility in ethyl benzoate at room temperature, greater than 10% by weight.

(Ink stability of the fine composition 1)
Ethyl benzoate was added to 8 parts by weight of the resulting polymer compound to make a total of 100 parts by weight, and dissolved by stirring to obtain a transparent and uniform ink. This was confirmed to have good ink dissolution stability without giving precipitates even when stored overnight at −10 ° C.

<Example 2>
In the step of obtaining the crude composition 1-1 of Example 1, the same operation as in Example 1 was performed except that the stirring conditions at 131 ° C. for 9 hours were changed to a temperature of 133 ° C. and a stirring time of 6 hours. Composition 2 was obtained.

(SEC measurement of fine composition 2)
The obtained polymer compound (fine composition 2) was subjected to SEC analysis in the same manner as in Example 1. As a result, the weight average molecular weight (Mw) was 22000.

(Solubility measurement of the fine composition 2)
The solubility of this in ethyl benzoate was examined and had a more improved solubility of greater than 10% by weight at room temperature.

(Ink stability of the fine composition 2)
A transparent and uniform ink was obtained in the same manner as in Example 1 except that the obtained polymer compound (exquisite composition 2) was used. This was confirmed to have good ink dissolution stability without giving precipitates even when stored overnight at −10 ° C.

<Example 3>
In the step of obtaining the crude composition 1-1 of Example 1, the same operation as in Example 1 was performed except that the stirring conditions at 131 ° C. for 9 hours were changed to a temperature of 132 ° C. and a stirring time of 6 hours. Composition 3 was obtained.

(SEC measurement of fine composition 3)
The obtained polymer compound (Precision Composition 3) was subjected to SEC analysis in the same manner as in Example 1. As a result, the weight average molecular weight (Mw) = 20000.

(Measurement of solubility of the fine composition 3)
The solubility of this in ethyl benzoate was examined and had a more improved solubility of greater than 10% by weight at room temperature.

(Ink stability of the fine composition 3)
A transparent and uniform ink was obtained in the same manner as in Example 1 except that the obtained polymer compound (exquisite composition 3) was used. This was confirmed to have good ink dissolution stability without giving precipitates even when stored overnight at −10 ° C.

<Comparative Example 1>
(Synthesis of "Precision Composition 4", a polymer compound containing the exemplified repeating unit (P-1) and having a weight average molecular weight (Mw) of 30000)
N, N′-bis (4-hydroxyphenyl) -N, N′-diphenyl-p-phenylenediamine (1.00 parts by weight) and 4,4′-difluorobenzophenone (0.49 parts by weight) under a nitrogen stream , Potassium carbonate (1.88 parts by weight), and N-methyl-2-pyrrolidone (23.4 parts by weight) were stirred at 148 ° C. for 15 hours. The obtained reaction mixture was filtered to remove insoluble matters, and then the filtrate was added to methanol. The resulting precipitate was collected by filtration, washed with a water-methanol mixture and methanol, and then dissolved in chloroform. After the chloroform solution was added to acetone and stirred for 30 minutes, the resulting precipitate was collected by filtration. Next, the obtained precipitate was washed with acetone, and then the solid obtained by drying was dissolved once again in chloroform. After the chloroform solution was added to acetone and stirred for 30 minutes, the resulting precipitate was collected by filtration and dried to give crude composition 4-1 (1.03 parts by weight, yield 74%). )

  The obtained crude composition 4-1 (1.00 part by weight) was dissolved in chloroform, and after this solution was added to acetone, the liquid layer was removed in 10 minutes, and the resulting precipitate was recovered. The obtained precipitate was washed with a chloroform / acetone mixed solvent, and then once again dissolved in chloroform. After this solution was added to acetone, the liquid layer was removed in 10 minutes, and the obtained precipitate was recovered. . The resulting precipitate was washed with a chloroform / acetone mixed solvent, dried, and then dissolved in chloroform. This chloroform solution was added to methanol, and the resulting precipitate was collected by filtration and then dried to obtain a purified composition 4 (0.53 parts by weight).

(SEC measurement of fine composition 4)
The obtained polymer compound (fine composition 4) was subjected to SEC analysis in the same manner as in Example 1. As a result, the weight average molecular weight (Mw) was 30000.

(Solubility measurement of the fine composition 4)
When the solubility of this product in ethyl benzoate was examined, it was found that the solubility was less than 10% by weight.

(Ink stability of the fine composition 4)
A transparent and uniform ink was obtained in the same manner as in Example 1 except that the obtained polymer compound (fine composition 4) was used. When this was stored overnight at −10 ° C., white crystals were precipitated, and the dissolution stability of the ink was found to be inferior to that of the polymer compound obtained in Example 1.

  As is apparent from the above results, the polymer compound of the present invention containing such a polymer compound of the present invention has high solubility in a solvent due to its low weight average molecular weight. The storage stability is good, and even after storage, there is little precipitate and a uniform film can be formed. An organic electroluminescent device having such a film has excellent heat resistance and can be driven stably for a long period of time.

It is typical sectional drawing which shows an example of the organic electroluminescent element of this invention. It is typical sectional drawing which shows the other example of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode

Claims (1)

By reprecipitation using a solvent having a higher hydrophobicity than the rich solvent as a poor solvent , the weight average molecular weight is 3000 to 27000, and the repeating unit represented by the following formula (1-1) is used. A method for producing a polymer compound, wherein an ether solvent is used as a rich solvent and an alkane solvent is used as a poor solvent .

[In the formula, R ^{1 to} R ⁵ each independently represents a substituent. P and q each independently represent an integer of 0 to ^5. r, s and t each independently represent 0 to 5; It represents an integer of 4. X represents a linking group selected from the following linking group group X ¹ .
<Linking group group X ¹ >

(In the formula, Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ³¹ and R ³² each independently represents a hydrogen atom or a substituent.)]

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