JP2007177250A - Polymer phosphor thin film, method for producing the same, and organic electroluminescence device - Google Patents

Abstract

〔Ａｒ₁ は、アリーレン基または複素環化合物基、水素、アルキル基等を示す。〕

【選択図】なしProvided is a polymeric phosphor thin film comprising a patterned conjugated polymer that can be easily prepared.
The polymer phosphor thin film has a thickness of 1 nm to 10 μm, the polymer phosphor includes one or more repeating units represented by the following formula (1), and the polymer phosphor thin film is , Containing at least 50% by weight of a polymer compound having a fluorescence peak wavelength of 400 nm or more and 800 nm or less, and two or more types of regions are formed in the polymer phosphor thin film. A patterned polymeric phosphor thin film characterized in that the existing proportions of the trans-type and cis-type vinylene groups contained in the main chain are different and have different fluorescence spectra.

[Ar ₁ represents an arylene group, a heterocyclic compound group, hydrogen, an alkyl group or the like. ]

[Selection figure] None

Description

The present invention relates to a patterned arylene vinylene polymer fluorescent thin film, a method for producing the same, and an organic electroluminescent element (hereinafter, also referred to as an organic EL element) produced using the polymeric fluorescent thin film.
Specifically, an arylene vinylene polymer phosphor thin film having two or more types of regions having different trans-type / cis-type existence ratios and different fluorescence spectra, and regions having different fluorescence spectra by partially irradiating light And an organic EL device having a light emitting layer made of the polymeric phosphor thin film.

An inorganic electroluminescence element (hereinafter, sometimes referred to as an inorganic EL element) using an inorganic phosphor as a light emitting material is used for display devices such as a planar light source or a flat panel display as a backlight. High voltage alternating current was necessary to make it.
In recent years, Tang et al. Fabricated an organic EL device having a two-layer structure in which an organic fluorescent dye is used as a light emitting layer and an organic charge transport compound used in an electrophotographic photoreceptor or the like is laminated. Realized high efficiency and high brightness organic EL element
9-194393). Compared to inorganic EL elements, organic EL elements have the characteristics that light emission of a large number of colors can be easily obtained in addition to low voltage drive and high luminance, so there are many element structures, organic fluorescent dyes, and organic charge transport compounds. Attempts have been reported [Japanese Journal of Applied Physics (Jpn.
. Appl. Phys. 27, L269 (1988)], [J. Appl. Phys., Volume 65,
3610 (1989)].

Up to now, low molecular weight organic fluorescent dyes have been generally used as the material for the light emitting layer, and as high molecular weight light emitting materials, WO90113148, JP-A-3-244630, Applied Physics.・ Letters (A
ppl. Phys. Lett. 58), 1982 (1991). In the examples of the specification of WO90113148, poly (p) converted into a conjugated polymer by depositing a soluble precursor on an electrode and performing heat treatment.
-Phenylene vinylene) thin film is obtained, and an EL device using the same is disclosed.
Japanese Patent Application Laid-Open No. 3-244630 exemplifies a conjugated polymer having characteristics that it is soluble in a solvent and does not require heat treatment. Applied Physics Letters (Appl. Phys. Lett.) Vol. 58, 1
Also on page 982 (1991), a polymer light-emitting material soluble in a solvent and an organic EL device produced using the same are described.
WO920203491 discloses a method for patterning by forming a soluble precursor into a film and partially forming a conjugated polymer by controlling detachment, and an organic EL element produced using the method. ing.

However, the patterned polymer phosphor thin films reported so far form a pattern by controlling the reaction from the conjugated polymer precursor to the conjugated polymer, resulting in the generation of desorbed molecules as impurities. The conjugated polymer precursor region is organic EL
When used as the light emitting layer of the device, the electrical characteristics were poor.
In addition, in order to obtain multiple colors in the same organic EL element using a conventional polymeric fluorescent substance, a method such as coating various kinds of light emitting materials can be considered, but the thickness of the light emitting layer to be used is Since it was very thin, it was not easy to manufacture.
Accordingly, there has been a demand for a polymer phosphor thin film made of a conjugated polymer that can be easily patterned and an organic EL device capable of multicolor emission.

An object of the present invention is to provide a polymeric fluorescent thin film comprising a patterned conjugated polymer that can be easily produced, a method for producing the same, and an organic E capable of multicolor emission that can be easily produced.
The object is to provide an L element.

In view of such circumstances, the present inventors have intensively studied a polymer phosphor thin film composed of a conjugated polymer, and as a result, made a polymer phosphor composed of a specific arylene vinylene polymer as a thin film, and partially It has been found that an organic EL element that emits light in a different color from each region can be easily obtained by changing the fluorescence spectrum by treating with light and using the polymeric phosphor thin film as a light emitting layer. It came.

ここで、Ａｒ₁ は、共役結合に関与する炭素原子数が４個以上２０個以下から
なるアリーレン基または複素環化合物基、Ｒ₁ 、Ｒ₂ はそれぞれ独立に水素、炭
素数１〜２０のアルキル基；炭素数６〜２０のアリール基；炭素数４〜２０の複
素環化合物基、シアノ基からなる群から選ばれる基を示す。
また、−ＣＲ₁ ＝ＣＲ₂ −は下記式（２）で示されるトランス型または下記式
（３）で示されるシス型である。〕

［２］厚さ１ｎｍ以上１０μｍ以下の高分子蛍光体薄膜であり、該高分子蛍光体
が、式（１）で示される繰り返し単位を１種類以上含み、かつ該高分子蛍光体薄
膜が、蛍光ピーク波長が４００ｎｍ以上８００ｎｍ以下であって、ポリスチレン
換算の数平均分子量が１０³ 〜１０⁷ の高分子化合物を５０重量％以上含有する
高分子蛍光体薄膜の一部に２００ｎｍ以上６００ｎｍ以下の光を照射することに
より、他の部分と互いに蛍光スペクトルの異なる領域を形成することを特徴とす
る［１］記載のパターニングされた高分子蛍光体薄膜の製造方法。
［３］少なくとも一方が透明または半透明である一対の陽極および陰極からなる
電極間に、少なくとも一層の発光層を有する有機エレクトロルミネッセンス素子
において、該発光層が、［１］記載のパターニングされた高分子蛍光体薄膜であ
ることを特徴とする有機エレクトロルミネッセンス素子。
［４］陰極と発光層との間に、該発光層に隣接して電子輸送性化合物からなる層
を設けたことを特徴とする［３］記載の有機エレクトロルミネッセンス素子。
［５］陽極と発光層との間に、該発光層に隣接して正孔輸送性化合物からなる層
を設けたことを特徴とする［３］記載の有機エレクトロルミネッセンス素子。
［６］陰極と発光層との間に、該発光層に隣接して電子輸送性化合物からなる層
を設け、かつ陽極と発光層との間に、該発光層に隣接して正孔輸送性化合物から
なる層を設けたことを特徴とする［３］記載の有機エレクトロルミネッセンス素
子。 That is, the present invention is the invention described below.
[1] A polymeric phosphor thin film having a thickness of 1 nm or more and 10 μm or less, wherein the polymeric phosphor includes one or more repeating units represented by the following formula (1), and the polymeric phosphor thin film comprises: Contains at least 50% by weight of a polymer compound having a fluorescence peak wavelength of 400 nm or more and 800 nm or less and a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁷ , and the polymer phosphor thin film has two or more regions. Patterned, characterized in that in each region, the abundance ratio of the vinylene group contained in the main chain of the polymer compound is different between the trans-type and cis-type, and has different fluorescence spectra. Polymer phosphor thin film.

Here, Ar ₁ is an arylene group or heterocyclic compound group having 4 to 20 carbon atoms involved in the conjugated bond, R ₁ and R ₂ are each independently hydrogen, alkyl having 1 to 20 carbon atoms Group; an aryl group having 6 to 20 carbon atoms; a group selected from the group consisting of a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group.
In addition, -CR ₁ = CR ₂ -is a trans type represented by the following formula (2) or a cis type represented by the following formula (3). ]

[2] A polymeric fluorescent thin film having a thickness of 1 nm to 10 μm, wherein the polymeric fluorescent substance includes one or more repeating units represented by the formula (1), and the polymeric fluorescent thin film is fluorescent Light having a peak wavelength of 400 nm or more and 800 nm or less and having a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁷ containing 50% by weight or more of a polymer phosphor thin film is irradiated with light having a wavelength of 200 nm to 600 nm. The method for producing a patterned polymeric fluorescent substance thin film according to [1], wherein a region having a fluorescence spectrum different from that of another part is formed by irradiation.
[3] In an organic electroluminescent device having at least one light emitting layer between a pair of anodes and cathodes, at least one of which is transparent or translucent, the light emitting layer has a patterned high height according to [1]. An organic electroluminescence device characterized by being a molecular phosphor thin film.
[4] The organic electroluminescence device according to [3], wherein a layer made of an electron transporting compound is provided adjacent to the light emitting layer between the cathode and the light emitting layer.
[5] The organic electroluminescence device according to [3], wherein a layer made of a hole transporting compound is provided adjacent to the light emitting layer between the anode and the light emitting layer.
[6] A layer made of an electron transporting compound is provided between the cathode and the light emitting layer, adjacent to the light emitting layer, and a hole transporting property is provided between the anode and the light emitting layer, adjacent to the light emitting layer. The organic electroluminescence device according to [3], wherein a layer made of a compound is provided.

The polymeric fluorescent substance thin film of the present invention can be formed by coating, and can be easily patterned by light to form regions having different fluorescence spectra. In addition, when the polymer phosphor thin film is used as a light emitting layer, an organic EL element capable of easily emitting multicolor light can be easily produced. The organic EL element is preferably used as an apparatus such as a multicolor planar light source or a flat panel display. it can.

Next, the patterned polymeric fluorescent thin film of the present invention will be described in detail.

The polymeric fluorescent substance used for the polymeric fluorescent substance thin film is demonstrated. The polymeric fluorescent substance has a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁷ , and the above formula (1
) And a fluorescent peak wavelength of 400 nm.
The arylene vinylene conjugated polymer having a thickness of 800 nm or less.
The vinylene group contained in the main chain of the polymer compound can have a trans-type or cis-type structure, and the fluorescence spectrum only needs to change depending on the abundance ratio of the trans-type and cis-type. Polyarylene vinylene and derivatives thereof, copolymers of arylene vinylene and phenylene and derivatives thereof, copolymers of arylene vinylene and thienylene and derivatives thereof, and copolymerization of arylene vinylene oligomers with ethers, esters, amides, and imides. Examples include coalescence.
Of these, polyarylene vinylene and its derivatives are particularly preferred. Examples of the polyarylene vinylene derivative include conjugated polymer compounds containing one or more repeating units represented by the formula (1), and the total of those repeating units is 50 mol% or more of all repeating units. Although it depends on the structure of the repeating unit, the repeating unit represented by the formula (1) is more preferably 70% or more of the entire repeating unit.
The polyarylene vinylene derivative is obtained by combining a divalent aromatic compound group or derivative thereof, a divalent heterocyclic compound group or derivative thereof, or a combination thereof as a repeating unit other than the repeating unit represented by the formula (1). A group or the like may be included.
Specific examples include groups shown in the following chemical formula 4 and groups obtained by combining them.

（Ｒ₁₄〜Ｒ₁₀₅ は、それぞれ独立に、水素、炭素数１〜２０のアルキル基、アル
コキシ基およびアルキルチオ基；炭素数６〜１８のアリール基およびアリールオ
キシ基；並びに炭素数４〜１４の複素環化合物基からなる群から選ばれた基であ
る。）
また、化４で示される繰り返し単位や他の繰り返し単位が、エーテル基、エス
テル基、アミド基、イミド基などを有する非共役の単位で連結されていてもよい
し、繰り返し単位にそれらの非共役部分が含まれていてもよい。これらの中でエ
ーテル基、エステル基が好ましく、エーテル基が特に好ましい。

(R _{14 to} R ₁₀₅ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group and an alkylthio group; an aryl group and aryloxy group having 6 to 18 carbon atoms; and a complex having 4 to 14 carbon atoms. It is a group selected from the group consisting of ring compound groups.)
In addition, the repeating unit represented by Chemical Formula 4 and other repeating units may be linked by a non-conjugated unit having an ether group, an ester group, an amide group, an imide group, or the like, and those non-conjugated units may be connected to the repeating unit. A portion may be included. Among these, an ether group and an ester group are preferable, and an ether group is particularly preferable.

As Ar ₁ of formula (1) in the polymer compound, an arylene group or heterocyclic compound group having a carbon atom which is involved in conjugated bonds is composed of 20 or less 4 or more, divalent shown in the chemical formula 4 Examples include an aromatic compound group or a derivative group thereof, a divalent heterocyclic compound group or a derivative group thereof, or a group obtained by combining them.

Among these, phenylene group, substituted phenylene group, biphenylene group, substituted biphenylene group, naphthylene group, substituted naphthylene group, 9,10-anthrylene group,
Substituted 9,10-anthrylene groups, 2,5-pyridyl groups, substituted 2,5-pyridyl groups, thienylene groups and substituted thienylene groups are preferred. More preferred are a phenylene group, a biphenylene group, a naphthylene group, a 2,5-pyridyl group, and a thienylene group.

The case where R ₁ and R _{2 in} formula (1) are hydrogen or a substituent other than a cyano group will be described. Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and pentyl. Group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group and the like, methyl group, ethyl group, pentyl group, hexyl group,
A heptyl group and an octyl group are preferable.
Examples of the aryl group include a phenyl group, 4-C ₁ ~C ₁₂ alkoxyphenyl group (
C ₁ -C ₁₂ indicates that a 1 to 12 carbon atoms. The same applies to the following. ), 4-C
₁ -C ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl groups.
Heterocyclic compound groups include 2-thienyl group, 2-pyrrolyl group, 2-furyl group, 2
Examples include-, 3- or 4-pyridyl group.

From the viewpoint of solvent solubility, Ar _{1 in} formula (1) is one or more alkyl groups having 4 to 20 carbon atoms, alkoxy groups and alkylthio groups, aryl groups and aryloxy groups having 6 to 18 carbon atoms, and 4 carbon atoms. It is preferable that 30 mol% or more of repeating units having a group selected from -14 heterocyclic compound groups are contained.

Examples of these substituents are as follows. Examples of the alkyl group having 4 to 20 carbon atoms include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and a dodecyl group, and a pentyl group, a hexyl group, a heptyl group, and an octyl group are preferable.
Examples of the alkoxy group having 4 to 20 carbon atoms include a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, and the like, such as a pentyloxy group and a hexyloxy group. , A heptyloxy group and an octyloxy group are preferable.
As the alkylthio group, a butylthio group, a pentylthio group, a hexylthio group,
A heptylthio group, an octylthio group, a decyloxy group, a dodecylthio group, etc. are mentioned, A pentylthio group, a hexylthio group, a heptylthio group, and an octylthio group are preferable.
As the aryl group, a phenyl group, a 4-C ₁ -C ₁₂ alkoxyphenyl group, 4
-C ₁ -C ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl groups.
A phenoxy group is illustrated as an aryloxy group.
Heterocyclic compound groups include 2-thienyl group, 2-pyrrolyl group, 2-furyl group, 2
Examples include-, 3- or 4-pyridyl group.
The number of these substituents varies depending on the molecular weight of the polymeric fluorescent substance and the constitution of the repeating unit, but from the viewpoint of obtaining a highly soluble polymeric fluorescent substance, these substituents are one or more per 600 molecular weight. It is more preferable.

The polymer phosphor used in the polymer phosphor thin film of the present invention may be a random, block or graft copolymer, or a polymer having an intermediate structure thereof, such as a block property. It may be a random copolymer. From the viewpoint of obtaining a polymer fluorescent substance having a high fluorescence quantum yield, a random copolymer having a block property and a block or graft copolymer are preferable to a complete random copolymer.

The terminal structure of the polymeric fluorescent substance used in the polymeric fluorescent thin film of the present invention varies depending on the synthesis method, and examples thereof include an aldehyde group and a methyl halide group. Although it may be used as it is, the terminal may be changed to another group by a low molecular weight compound having a functional group capable of reacting with and binding to these terminal groups. The structure of the bonding portion between the terminal group and the main chain is not particularly limited, but it is preferable that a conjugated bond is formed with the main chain via a vinylene group. Examples of the structure of these terminal groups include a pyrenyl group, anthryl group, naphthyl group, alkoxyphenyl group, quinolyl group, pyridyl group, and the like, and a pyrenyl group and an anthryl group are preferable.
In addition, since the organic EL element of the present invention utilizes light emission from a thin film, the polymer fluorescent substance having fluorescence in a solid state is used.

As an example of the polymeric fluorescent substance used for the polymeric fluorescent substance thin film of the present invention, more specifically, a polymer comprising the respective repeating units represented by the following formulas (4) to (8),
A block copolymer or a random copolymer composed of two or more different side chain lengths of each repeating unit represented by formula (4) to formula (7), a repeating unit represented by formula (5) and a formula An alternating copolymer of repeating units represented by (6) or a random copolymer having a molar ratio of 10: 1 to 1: 1, a repeating unit represented by formula (5) and a repeat represented by formula (7) An alternating copolymer of units or a random copolymer having a molar ratio of 10: 1 to 1: 5, an alternating copolymer of a repeating unit represented by formula (4) and a repeating unit represented by formula (8), etc. Is exemplified.

（ここで、Ｒ₁₀₆ 〜Ｒ₁₁₁ 、Ｒ₁₁₃ 〜Ｒ₁₁₄ は、それぞれ独立に、水素、炭素数
１〜２０のアルキル基、アルコキシ基およびアルキルチオ基；炭素数６〜１８の
アリール基およびアリールオキシ基；並びに炭素数４〜１４の複素環化合物基か
らなる群から選ばれた基である。また、Ｒ₁₁₂ は、炭素数１〜１０のアルキレン
基、炭素数６〜１８のアリーレン基、並びに炭素数４〜１４の２価の複素環化合
物基からなる群から選ばれた基である。）

(Where R _{106 to} R ₁₁₁ and R _{113 to} R ₁₁₄ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group, and an alkylthio group; an aryl group and aryloxy group having 6 to 18 carbon atoms) And a group selected from the group consisting of heterocyclic compound groups having 4 to 14 carbon atoms, and R ₁₁₂ is an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 18 carbon atoms, and a carbon number. It is a group selected from the group consisting of 4 to 14 divalent heterocyclic compound groups.)

Examples of specific substituents of the formulas (4) to (8) include R _{106 to} R ₁₁₁ , R ₁₁₃ to
In the case of R ₁₁₄ , examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and a dodecyl group. A methyl group, an ethyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group are preferred.
Examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group. And
A methoxy group, an ethoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group are preferred.
Examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decylthio group, and a dodecylthio group. , A heptylthio group and an octylthio group are preferable.
As the aryl group, a phenyl group, a 4-C ₁ -C ₁₂ alkoxyphenyl group, 4
-C ₁ -C ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl groups.
A phenoxy group is illustrated as an aryloxy group.
Heterocyclic compound groups include 2-thienyl group, 2-pyrrolyl group, 2-furyl group, 2
Examples include-, 3- or 4-pyridyl group.

In the case of R ₁₁₂ , examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and a decylene group. An ethylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group and a decylene group are preferred.
As an arylene group, a phenylene group, a substituted phenylene group, a biphenylene group,
A substituted biphenylene group, a naphthylene group, a substituted naphthylene group, a 9,10-anthrylene group, and a substituted 9,10-anthrylene group are exemplified, and a phenylene group, a biphenylene group, and a naphthylene group are preferable.
Examples of the divalent heterocyclic compound group include a 2,5-pyridinediyl group, a substituted 2,5-pyridinediyl group, a thienylene group, and a substituted thienylene group, and a 2,5-pyridinediyl group and a thienylene group are preferable.

Examples of the good solvent for the arylene vinylene polymer phosphor used in the polymer phosphor thin film of the present invention include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene and the like. Although depending on the structure and molecular weight of the polymer compound, it can usually be dissolved in these solvents in an amount of 0.1 wt% or more.

The vinylene group in the repeating unit represented by the formula (1) or (4) to (8) can be either a trans type or a cis type, and the proportion thereof is determined by the method for synthesizing the polymeric fluorescent substance, It can be controlled by the processing method.
Although the details of the mechanism are not clear, the fluorescence spectrum changes depending on the ratio of trans type: cis type. Specifically, the more the trans type, the longer the fluorescence peak wavelength. The ratio of trans type: cis type is usually 100: 0, although it depends on the synthesis method.
It is between 20:80, and the polymer phosphor containing cis-type vinylene is irradiated with light of 200 nm or more and 600 nm or less, and a change from cis-type to trans-type can be caused according to the irradiation amount.

The arylene vinylene polymer fluorescent substance used in the polymeric fluorescent thin film of the present invention preferably has a molecular weight of 10 ³ to 10 ⁷ in terms of polystyrene, and the degree of polymerization thereof varies depending on the repeating structure and the ratio thereof. In general, from the viewpoint of film formability, the total number of repeating structures is preferably 4 to 10000, more preferably 5 to 3000,
Especially preferably, it is 10-2000.
Further, when these polymer compounds are used as a light emitting material for an organic EL device, the purity affects the light emission characteristics, and therefore it is desirable to carry out a purification treatment such as reprecipitation purification and fractionation by chromatography after synthesis.

The method for synthesizing the arylene vinylene polymer fluorescent substance used in the polymeric phosphor thin film of the present invention is not particularly limited. For example, dialdehyde in which two aldehyde groups are bonded to an aromatic ring or an aromatic ring having a substituent. Examples include Wittig reaction from a diphosphonium salt obtained from a compound, a compound in which two halogenated methyl groups are bonded to an aromatic ring or an aromatic ring having a substituent, and triphenylphosphine. In this case, a polymer containing a relatively large amount of cis type is obtained.
Other synthesis methods include a dehydrohalogenation method from a compound in which two halogenated methyl groups are bonded to an aromatic ring or an aromatic ring having a substituent. In this case, the ratio of the transformer type is large.
Further, a sulfonium salt decomposition method for obtaining a polymeric fluorescent substance by heat treatment from an intermediate obtained by polymerizing a sulfonium salt of a compound in which two halogenated methyl groups are bonded to an aromatic ring or an aromatic ring having a substituent with an alkali Is exemplified. In this case, the intermediate is solvent-soluble, and the polymeric fluorescent substance is not necessarily soluble.
Also in this case, the ratio of the transformer type is large.
Also, a Knoevengel method from a dialdehyde compound in which two aldehyde groups are bonded to an aromatic ring or an aromatic ring having a substituent, and a compound in which two acetonitrile groups are bonded to an aromatic ring or an aromatic ring having a substituent Is exemplified. In this case, a polymer containing a relatively large amount of cis type is obtained.
In any synthesis method, a compound having a skeleton other than an aromatic ring is added as a monomer, and the structure of the repeating unit contained in the polymer compound to be generated can be changed by changing the proportion of the compound. 50 repeating units
It may be added and adjusted so as to be mol% or more, and copolymerization may be carried out.
Among these, the method using the Wittig reaction and the Knoevengel method are preferable in that the reaction is controlled, the yield, and the cis type is contained in a large amount.

More specifically, a method for synthesizing the arylene vinylene polymer phosphor used in the polymer phosphor thin film of the present invention will be described.
For example, when obtaining the polymeric fluorescent substance by Wittig reaction, for example, first,
Bis (halogenated methyl) compounds, more specifically, for example, 2,5-dioctyloxy-p-xylylene dibromide in N, N-dimethylformamide solvent,
A phosphonium salt is synthesized by reacting with triphenylphosphine, and this and a dialdehyde compound, more specifically, for example, terephthalaldehyde is condensed with, for example, lithium ethoxide in ethyl alcohol, to form phenylene. A polymeric fluorescent substance containing a vinylene group and a 2,5-dioctyloxy-p-phenylene vinylene group is obtained. At this time, in order to obtain a copolymer, two or more kinds of diphosphonium salts and / or two or more kinds of dialdehyde compounds may be reacted.

Next, the manufacturing method of the patterned polymeric fluorescent substance thin film in this invention is demonstrated.
When preparing the polymer phosphor thin film, using these arylene vinylene polymer phosphors, applying a solution containing the polymer phosphor, removing the solvent by drying,
A 10 μm thin film is formed. Next, a patterned thin film is formed by irradiating light that can be converted from a cis type to a trans type through a mask in which a portion to be irradiated with light is opened.
As a patterning method, a method of irradiating light through a mask or the like is simple and preferable. Since the amount of change in the fluorescence spectrum increases with the amount of light irradiation,
A plurality of regions having different fluorescence spectra in multiple stages can be formed in one thin film by performing multiple exposures with different irradiation intensities or irradiation times.
Although it depends on the structure of the polymer compound, it can be converted from a cis type to a trans type by irradiating light within a range of wavelengths of 200 nm to 600 nm, which is absorbed by the polymer compound, preferably 200 nm. More than 400 nm. What is necessary is just to irradiate the light quantity which causes the fluorescence spectrum change of a required magnitude | size.

Next, the organic EL element of the present invention will be described in detail.
The organic EL device of the present invention uses the patterned polymer phosphor thin film as a light emitting layer.
The structure of the organic EL device of the present invention is not particularly limited as long as the light emitting layer provided between a pair of electrodes, at least one of which is transparent or translucent, is the above-described polymer phosphor thin film, and a known structure is adopted. Is done.

For example, a structure in which the polymer phosphor thin film or a polymer phosphor thin film layer containing a charge transport material (which means a generic name of an electron transport material and a hole transport material) is used as a light-emitting layer and a pair of electrodes is provided on both sides thereof A laminate of a hole transport layer containing a hole transport material between the light emitting layer and the anode, a laminate of an electron transport layer containing an electron transport material between the light emitting layer and the cathode Further, a layer in which a hole transport layer containing a hole transport material is laminated between the light emitting layer and the anode, and an electron transport layer containing an electron transport material is laminated between the light emitting layer and the cathode. Illustrated.

Further, the present invention includes a case where each layer is a single layer and a combination of a plurality of layers.
Further, for example, a light emitting material described below may be mixed and used in the light emitting layer. Alternatively, a layer in which a conjugated polymer compound and / or a charge transport material is dispersed in a non-conjugated polymer compound can be used as long as patterning is possible.

A charge transport material used together with an arylene vinylene polymer fluorescent substance in the light emitting layer, that is, a known material can be used as an electron transport material or a hole transport material,
Although not particularly limited, examples of the hole transport material include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, and triphenyldiamine derivatives, and examples of the electron transport material include oxadiazole derivatives, anthraquinodimethane and derivatives thereof, benzoquinone and derivatives thereof. And naphthoquinone and derivatives thereof, anthraquinone and derivatives thereof, tetracyanoanthraquinodimethane and derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, and the like.

Specifically, JP-A-63-70257, JP-A-63-175860, JP-A-2-135359, 2-135361, 2-209998, 3-
Examples described in Japanese Patent Nos. 37992 and 3-152184 are exemplified.
The hole transport material is preferably a triphenyldiamine derivative, the electron transport material is preferably an oxadiazole derivative, benzoquinone and a derivative thereof, anthraquinone and a derivative thereof, 8-hydroxyquinoline and a metal complex of the derivative,
In particular, as a hole transport material, 4,4′-bis (N (3-methylphenyl) -N—
Phenylamino) biphenyl, 2- (4-biphenylyl) as an electron transport material
-5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, and tris (8-quinolinol) aluminum are preferred.
Of these, one or both of an electron transporting compound and a hole transporting compound may be used simultaneously. These may be used singly or in combination of two or more.

When a charge transport layer is further provided between the light emitting layer and the electrode, the charge transport layer may be formed using these charge transport materials.
In addition, when using a charge transport material mixed in the light emitting layer, the amount of charge transport material used varies depending on the type of compound used, etc. What is necessary is just to determine suitably in consideration of them in the quantity range which does not inhibit. Usually, it is 1 to 40 weight% with respect to the whole light emitting layer, More preferably, it is 2 to 30 weight%.

Although it does not specifically limit as a known luminescent material which can be used with an arylene vinylene type | system | group fluorescent substance in a light emitting layer, For example, a naphthalene derivative, anthracene and its derivative, perylene and its derivative, polymethine type, xanthene type, coumarin type, cyanine type Pigments such as, metal complexes of 8-hydroxyquinoline and its derivatives, aromatic amines, tetraphenylcyclopentadiene and its derivatives,
Tetraphenylbutadiene and its derivatives can be used. Specifically, for example, known ones such as those described in JP-A-57-51781 and 59-194393 can be used.

Next, a typical method for producing the organic EL element of the present invention will be described. As a pair of electrodes composed of an anode and a cathode, a transparent or translucent electrode is formed by forming a transparent or translucent electrode on a transparent substrate such as glass or transparent plastic.
As the material for the anode, a conductive metal oxide film, a translucent metal thin film, or the like is used. Specifically, a film (NESA etc.) made of conductive glass made of indium tin oxide (ITO), tin oxide, etc., Au, Pt, Ag, Cu
Etc. are used. As a manufacturing method, a vacuum deposition method, a sputtering method, a plating method, or the like is used.

When forming a hole transport layer on this anode, it is based on the following method. That is, a spin coating method, a casting method, a dipping method, a bar coating method, a roll coating method or the like using a melt, solution or mixed solution of a hole transport material, or a polymer matrix material and a hole transport material Examples of the coating method include spin coating method, casting method, dipping method, bar coating method, roll coating method and the like using a solution or mixed solution after being mixed and dispersed in a solution state or a molten state. Among these, it is particularly preferable to form a film using a solution or a mixed solution by a coating method such as a spin coating method, a casting method, a dipping method, a bar coating method, or a roll coating method.

The film thickness of the hole transport layer is preferably 1 nm to 1 μm, more preferably 2 to 2.
500 nm. 5-100nm to increase luminous efficiency by increasing current density
The range of is preferable.
Next, the polymeric fluorescent substance thin film is formed. After forming the thin film, for example, light irradiation is performed through a mask to perform patterning. What is necessary is just to select a pattern suitably according to the content to display, such as a segment and a matrix.

The thickness of the light emitting layer is preferably 1 nm to 1 μm, more preferably 2 nm to
500 nm. 5-100nm to increase luminous efficiency by increasing current density
The range of is preferable.
In addition, when the hole transport layer or the light emitting layer is thinned by a coating method, in order to remove the solvent, after forming the hole transport layer and / or after forming the light emitting layer, preferably under reduced pressure or in an inert atmosphere, It is desirable to heat dry at a temperature of 30 to 300 ° C, more preferably 60 to 200 ° C.

Moreover, when an electron carrying layer is further laminated | stacked on this light emitting layer, it is preferable to form an electron carrying layer on it after providing a light emitting layer by said method.

The method for forming the electron transport layer is not particularly limited, but it can be applied by vacuum deposition from a powder state, spin coating after dissolving in a solution, casting, dipping, bar coating, roll coating, or the like. Or a coating method such as a spin coating method, a casting method, a dipping method, a bar coating method, or a roll coating method after mixing and dispersing a polymer compound and an electron transport material in a solution state or a molten state. it can.

The polymer compound to be mixed is not particularly limited, but those that do not extremely inhibit electron transport are preferable, and those that do not strongly absorb visible light are preferably used.
For example, poly (N-vinylcarbazole), polyaniline and its derivatives,
Polythiophene and its derivatives, poly (p-phenylene vinylene) and its derivatives, poly (2,5-thienylene vinylene) and its derivatives, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, poly Examples include siloxane. In terms of easy film formation, it is preferable to use a coating method when using a polymer compound.

The film thickness of the electron transport layer needs to be at least such that no pinholes are generated. However, if the thickness is too large, the resistance of the element increases and a high driving voltage is required, which is not preferable. Therefore, the thickness of the electron transport layer is preferably 1 nm to 1 μm, more preferably 2 nm to 500 nm, and particularly preferably 5 to 100 nm.

Next, an electrode is provided on the light emitting layer or the electron transport layer. This electrode becomes an electron injection cathode. The material is not particularly limited, but a material having a small ionization energy is preferable. For example, Al, In, Mg, Ca, Li, Mg—Ag alloy,
In-Ag alloy, Mg-In alloy, Mg-Al alloy, Mg-Li alloy, Al-L
An i alloy, a graphite thin film, or the like is used. As a method for producing the cathode, a vacuum deposition method, a sputtering method or the like is used.

More specifically, FIG. 1 shows the configuration of an example of the patterned polymeric fluorescent thin film of the present invention. For example, an arylene vinylene polymer fluorescent substance thin film is formed on a glass substrate, and first, the areas 1 and 2 are masked so as not to be exposed to light, and the area 3 is irradiated with intense light or light for a long time. Next, the regions 1 and 3 are masked, and the region 2 is irradiated with weak light or light for a short time. Thus, for example, 1, 2,
The fluorescent colors in the region 3 are green, yellow, and red-orange, respectively.

FIG. 2 shows a configuration of an example of an organic electroluminescence element using a patterned polymer phosphor thin film similar to that shown in FIG. 1 as a light emitting layer.
For example, an arylene vinylene polymer phosphor thin film is formed on a glass substrate with ITO as a transparent electrode 4 and the regions 1, 2, and 3 are formed in the same manner as shown in FIG.
3 is irradiated with different amounts of light. At this time, if necessary, a charge transport layer is formed. Next, cathodes indicated by 1 ′, 2 ′, and 3 ′ are formed. Further, 5 conductors are attached to connect these cathodes and external circuits. When this organic electroluminescence element is viewed from the transparent electrode side, by applying a voltage between the transparent electrode and the cathode, from the cathode portion of 1 ′, 2 ′, 3 ′, for example, green, yellow,
Red-orange electroluminescence can be seen.
In these examples, segment-type examples are shown. However, by using a finer transparent electrode and a mask, the same patterning is performed in a stripe shape, and then a cathode is formed in a lattice shape. Matrix-type multicolor elements can also be created.

Examples of the present invention are shown below, but the present invention is not limited to these.
Here, for the number average molecular weight, the number average molecular weight in terms of polystyrene was determined by gel permeation chromatography (GPC) using chloroform as a solvent.
Reference example 1
<Synthesis and Evaluation of Polymer Compound 1>
2,5-Dioctyloxy-p-xylylene dibromide was reacted with triphenylphosphine in N, N-dimethylformamide solvent to synthesize phosphonium salts. The obtained phosphonium salt 47.75 parts by weight, terephthalaldehyde 6.7
Part by weight was dissolved in ethyl alcohol. An ethyl alcohol solution containing 5.8 parts by weight of lithium ethoxide was dropped into an ethyl alcohol solution of a phosphonium salt and a dialdehyde and polymerized at room temperature for 3 hours. After standing overnight at room temperature, the precipitate was filtered off, washed with ethyl alcohol, dissolved in chloroform, and ethanol was added thereto to form a precipitate again. This was dried under reduced pressure to obtain 8.0 parts by weight of a polymer. This is called polymeric fluorescent substance 1. The repeating unit of the polymeric fluorescent substance 1 calculated from the monomer charge ratio and the molar ratio thereof are shown below.

モル比 ５０：５０（ただし、２つの繰り返し単位は交互に結合している。）
該高分子蛍光体１のポリスチレン換算の数平均分子量は、１．０×１０⁴ であ
った。該高分子蛍光体１の構造については赤外吸収スペクトル、ＮＭＲで確認し
た。また、ＮＭＲから見積ったビニレン基のシス型：トランス型の比は６６：３
４であった。

Molar ratio 50:50 (however, the two repeating units are bonded alternately)
The number average molecular weight in terms of polystyrene of the polymeric fluorescent substance 1 was 1.0 × 10 ⁴ . The structure of the polymeric fluorescent substance 1 was confirmed by infrared absorption spectrum and NMR. The ratio of cis type: trans type of vinylene group estimated from NMR is 66: 3.
4.

Example 1
<Preparation and evaluation of polymer phosphor thin film>
3 by spin coating using 1.0 wt% toluene solution of polymeric fluorescent substance 1
The film was formed with a thickness of 0 nm. Place this in the atmosphere on a 120 ° C hot plate,
The light from the fluorescent lamp was irradiated for 10 minutes through the mask.
The fluorescence of the polymer phosphor thin film that was not exposed to light was green.
It had a fluorescence peak at nm. On the other hand, the fluorescence of the part irradiated with light is red-orange, 59
It had a fluorescence peak at 0 nm. The portion that was not exposed to light was scraped off and dissolved in chloroform-D, and the NMR was measured. The ratio of the cis form to the trans form of the vinylene group was about 65:35. Moreover, it was about 40:60 when the part which received light was measured similarly.

Example 2
<Creation and evaluation of organic EL element>
By sputtering, on a glass substrate with an ITO film with a thickness of 40 nm,
Using a 1.0 wt% chloroform solution of poly (N-vinylcarbazole), a film was formed by dipping to a thickness of 70 nm, followed by 1.0 wt% of polymer compound 1.
After forming a film with a thickness of 40 nm by spin coating using a% toluene solution, it was placed on a hot plate at 120 ° C. in the atmosphere, and irradiated with fluorescent light for 10 minutes through a mask to form a pattern.
Furthermore, after drying this at 80 degreeC under reduced pressure for 1 hour, as an electron carrying layer, a tris (
8-quinolinol) aluminum (Alq ₃ ) was deposited at a rate of 0.1 to 0.2 nm / s at 60 nm.
Finally, an aluminum-lithium alloy (Al: Li = about 1) is used as a cathode thereon.
00: 1 weight ratio) was deposited by 100 nm to prepare an organic EL device. The degree of vacuum at the time of vapor deposition was 8 × 10 ⁻⁶ Torr or less.
When a voltage of 12.5 V was applied to the electrode formed in the region not irradiated with light of this element, a current with a current density of 224 mA / cm ² flowed and a luminance of 14170 cd / m ^2.
Yellow-green EL emission was observed. The brightness was almost proportional to the current density. Also,
The EL peak wavelength was 540 nm.
Next, when a voltage of 12.5 V was applied to the electrode formed in the light-irradiated region of this element, a current with a current density of 91.2 mA / cm ² flowed, and red-orange EL emission with a luminance of 527 cd / m ² was observed. It was done. The brightness was almost proportional to the current density. E
The L peak wavelength was 592 nm.

Example 3
<Creation and evaluation of polymer phosphor thin film, creation and evaluation of organic EL element>
3 by spin coating using 1.0 wt% toluene solution of polymeric fluorescent substance 1
A film having a thickness of 0 nm is formed, placed on a hot plate at 120 ° C. in the atmosphere, and irradiated with light from a fluorescent lamp through a mask while being shifted little by little for 1 to 10 minutes.
The fluorescence of the portion of the polymeric fluorescent thin film that did not receive light was green, about 54
A portion having a fluorescence peak at 0 nm and irradiated with light has a fluorescent color ranging from green (fluorescence peak of about 540 nm) to red-orange (fluorescence peak of about 590 nm) depending on the irradiation time.

Example 4
In the same manner as in Example 2, if the same polymeric phosphor thin film as in Example 3 is used as the light emitting layer and an electrode is formed in each fluorescent color region, and a voltage is applied, one element is formed. Light emission of various colors from green to red-orange can be obtained.

The figure which shows the structure of one example of the polymeric fluorescent substance thin film patterned of this invention. The figure which shows the structure of an example of the organic electroluminescent element which uses the patterned polymeric fluorescent substance thin film as a light emitting layer.

Explanation of symbols

1 Non-light-irradiated part (fluorescent green).
2 Weakly irradiated part (fluorescent yellow).
3 Strong light irradiated part (fluorescent reddish orange).
1 'cathode (electroluminescence green).
2 'cathode (electroluminescence yellow).
3 'cathode (electroluminescence red orange).
4 Anode (transparent electrode).
5 Conductor.

Claims (5)

A polymeric phosphor thin film having a thickness of 1 nm or more and 10 μm or less, wherein the polymeric phosphor includes one or more repeating units represented by the following formula (1), and the polymeric phosphor thin film has a fluorescence peak wavelength Is not less than 400 nm and not more than 800 nm, contains 50% by weight or more of a polymer compound having a polystyrene-reduced number average molecular weight of 10 ³ to 10 ⁷ , and two or more types of regions are formed in the polymer phosphor thin film. Patterned polymer fluorescence characterized in that the proportion of vinylene groups contained in the main chain of the polymer compound in each region is different between trans-type and cis-type, and has different fluorescence spectra. Body thin film.

[Wherein Ar ₁ is an arylene group or heterocyclic compound group having 4 to 20 carbon atoms involved in the conjugated bond, R ₁ and R ₂ are each independently hydrogen, C 1-20 An alkyl group; an aryl group having 6 to 20 carbon atoms; a group selected from the group consisting of a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group;
In addition, -CR ₁ = CR ₂ -is a trans type represented by the following formula (2) or a cis type represented by the following formula (3). ]

2. The patterned polymeric fluorescent substance according to claim 1, wherein the light emitting layer is an organic electroluminescent device having at least one light emitting layer between a pair of anode and cathode electrodes, at least one of which is transparent or translucent. An organic electroluminescence device characterized by being a thin film. The organic electroluminescent device according to claim 2, wherein a layer made of an electron transporting compound is provided adjacent to the light emitting layer between the cathode and the light emitting layer. 3. The organic electroluminescence device according to claim 2, wherein a layer made of a hole transporting compound is provided adjacent to the light emitting layer between the anode and the light emitting layer. A layer made of an electron transporting compound is provided adjacent to the light emitting layer between the cathode and the light emitting layer, and a hole transporting compound is adjacent to the light emitting layer between the anode and the light emitting layer. The organic electroluminescent element according to claim 2, wherein a layer comprising:

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