JP2002155274A - Polymeric fluorophor and polymeric light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymeric fluorophor emitting intense fluorescence, and to provide a polymeric LED of high emission efficiency by the use of the fluorophor. SOLUTION: This polymeric fluorophor emits a visible fluorescence in a solid state, has a number-average molecular weight of 1×103 to 1×108 calculated as polystyrene, and has at least one kind of recurring unit of the formula (1): Ar1-(CR1=CR2)m [Ar1 is an arylene or the like having a substituent of the formula (2): X-Ar2 (X is 0 or the like; R3, R4 and R5 are each H or the like; and Ar2 is a univalent heterocyclic compound group or the like); m is 0 or 1; and R1 and R2 are each H or the like]; wherein the recurring unit(s) of the formula (1) totals 9-100 mol% based on the grand total recurring units. The other objective a polymeric LED using the polymeric fluorophor is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer fluorescent material and a polymer light emitting device prepared using the polymer fluorescent material.
(Hereinafter, may be referred to as a polymer LED).

[0002]

2. Description of the Related Art High-molecular-weight light-emitting materials (polymer fluorescent materials) are different from low-molecular light-emitting materials in that they are soluble in solvents and can form a light-emitting layer in a light-emitting element by a coating method. Arylene vinylene or polyarylene is known. Among these, from the viewpoint of improving solubility in an organic solvent, etc., a polymeric fluorescent substance having a substituent on the aromatic ring of the arylene group of polyarylene vinylene or polyarylene, for example, a phenoxy group on the aromatic ring of the arylene group And polyarylenevinylenes having a thiophenoxy group are known [Macromolecular Chemical Physics (Macromol. Che).
m. Phys. ) Vol. 200, p. 552 (1999)
Year)〕. However, the known polymeric fluorescent substance having a phenoxy group or a thiophenoxy group on the aromatic ring of the arylene group still has insufficient fluorescence intensity and the polymer L
When used for the light emitting layer of the ED, the luminous efficiency was insufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer phosphor having strong fluorescence and a polymer LED having high luminous efficiency using the same.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, they have visible fluorescence in a solid state and a number average molecular weight in terms of polystyrene of 1 × 10 ^3.
A polymeric fluorescent substance having a molecular weight of up to 1 × 10 ^{8, wherein} at least one kind of the repeating unit represented by the following formula (1) is contained, and the total of those repeating units exceeds 9 mol% of all the repeating units and is 100 mol % Or less of the polymer fluorescent material has strong fluorescence, and a polymer LED using the polymer fluorescent material.
Is high luminous efficiency, the polymer LED is a planar light source,
The present inventors have found that they can be used as backlights for segment display devices, dot matrix display devices, and liquid crystal display devices, and have reached the present invention. -Ar _1- (CR ₁ = CR ₂ ) _m- (1) [where Ar ₁ is an arylene group having 6 to 60 carbon atoms or a divalent complex having 2 to 60 carbon atoms. A ring compound group having at least one substituent represented by the following formula (2). m is 0 or 1. R
₁ and R ₂ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms;
And a group selected from the group consisting of an aryl group, a monovalent heterocyclic compound group having 2 to 60 carbon atoms and a cyano group. -X-Ar ₂ (2) (where X is -O-, -S-, -SiR ₃ R ₄ -,-
And a group represented by NR ₅ —, —CO—, —COO—, or —SO ₂ —. Here, R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms and 2 to 60 carbon atoms. And a group selected from the group consisting of monovalent heterocyclic compound groups. Ar ₂ has 2 to 60 carbon atoms.
A monovalent heterocyclic compound group, or an aryl group having 6 to 60 carbon atoms, a linear, branched or cyclic alkyl group having 5 to 20 carbon atoms, a linear chain having 1 to 20 carbon atoms An alkoxy group having a branched or cyclic alkyl group, a straight-chain having 1 to 20 carbon atoms, an alkylthio group having a branched or cyclic alkyl group, a mono-, di- or trialkylsilyl group having 1 to 60 carbon atoms, A mono- or dialkylamino group having 1 to 40 carbon atoms, an aryl group having 6 to 60 carbon atoms having at least one substituent, an aryloxy group having 6 to 60 carbon atoms, an arylalkyl group having 7 to 60 carbon atoms, carbon number 7-60 arylalkoxy group, carbon number 8
Arylalkenyl group having 6 to 60 carbon atoms, monoarylamino group having 6 to 60 carbon atoms, diarylamino group having 16 to 60 carbon atoms, and monovalent heterocyclic compound having 2 to 60 carbon atoms An aryl group having at least one substituent selected from the group consisting of

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polymeric fluorescent substance of the present invention has visible fluorescence in a solid state and has a polystyrene equivalent number average molecular weight of 1 × 10 ^3.
In the polymeric fluorescent substance of １1 × 10 ⁸ , one or more kinds of the repeating units represented by the formula (1) are contained, and the total of those repeating units is more than 9 mol% and not more than 100 mol% of all the repeating units. The total of the repeating units is preferably at least 20 mol% of all the repeating units, and more preferably at least 50 mol%. Ar ₁ in the formula (1) is an arylene group having 6 to 60 carbon atoms or 2 to 6 carbon atoms involved in conjugation.
0 is a divalent heterocyclic compound group having at least one substituent represented by the above formula (2). Ar ₁ may further have a substituent. When Ar ₁ has a plurality of substituents, they may be the same or different. The carbon number of Ar ₁ does not include the carbon number of the substituent. m is 0 or 1.

R ₁ and R ₂ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms;
An aryl group having 6 to 60 carbon atoms, a monovalent heterocyclic compound group having 2 to 60 carbon atoms and a group selected from the group consisting of a cyano group, wherein the aryl group and the monovalent heterocyclic compound group are further substituted It may have a group.

In the present invention, an arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon.
Here, the aromatic hydrocarbon is a hydrocarbon that is a parent of the aromatic compound, and refers to a hydrocarbon containing a benzene ring,
Those having a condensed ring, those having an independent benzene ring or a condensed ring bonded directly or via a group such as vinylene are included. As an arylene group, a phenylene group (for example,
The following formulas 1 to 3), naphthalenediyl group (formulas 4 to
13), anthracenylene group (formulas 14 to 19 in the following figure),
Examples include a biphenylene group (formulas 20 to 25 in the following figure), a triphenylene group (formulas 26 to 28 in the following figure), a condensed ring compound group (formulas 29 to 38 in the following figure), and the like. Among them, a phenylene group, a biphenylene group, and a fluorenediyl group (formulas 36 to 38 in the following figure) are preferable.

[0008]

[0009]

[0010]

[0011]

[0012]

In the present invention, the divalent heterocyclic compound group means an atomic group obtained by removing two hydrogen atoms from the heterocyclic compound. Here, a heterocyclic compound is an organic compound having a cyclic structure in which the elements constituting the ring include not only carbon atoms but also hetero atoms such as oxygen, sulfur, nitrogen, phosphorus, boron, and arsenic in the ring. A thing. Examples of the divalent heterocyclic compound group include the following. A bivalent heterocyclic compound group containing nitrogen as a hetero atom; a pyridinediyl group (formulas 39 to 44 in the figure below), a diazaphenylene group (formulas 45 to 48 in the figure below), a quinolinediyl group (formulas 49 to 63 in the figure below), Quinoxaline diyl group (Formula 64 to
68), an acridinediyl group (formulas 69 to 72 in the figure below),
A bipyridyldiyl group (formulas 73 to 75 in the figure below), a phenanthrolinediyl group (formulas 76 to 78 in the figure below), and the like. A group having a fluorene structure containing silicon, nitrogen, sulfur, selenium and the like as a hetero atom (Formulas 79 to 93 in the following figure). 5 containing silicon, nitrogen, sulfur, selenium, etc. as hetero atoms
Membered ring heterocyclic compound group: (Formulas 94 to 98 in the following figure). 5-membered condensed heterocyclic compound group containing silicon, nitrogen, sulfur, selenium and the like as a hetero atom: (Formulas 99 to
108). A 5-membered heterocyclic compound group containing silicon, nitrogen, sulfur, selenium, etc. as a hetero atom, and bonded at the α-position of the hetero atom to form a dimer or oligomer: (Formulas 109 to 110 in the following figure): Is mentioned.
5-membered ring heterocyclic compound group containing silicon, nitrogen, sulfur, selenium, etc. as a hetero atom, a group bonded to a phenyl group at the α-position of the hetero atom: (Formulas 111 to 117 in the following figure)
Is mentioned.

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

In each of the above examples of Ar ₁ , at least one of R is a substituent represented by the above formula (2). R other than the substituent represented by the formula (2) is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. Alkoxy group having a cyclic alkyl group, alkylthio group having a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, monoalkylsilyl group, dialkylsilyl group or trialkylsilyl group having 1 to 60 carbon atoms (Hereinafter sometimes referred to as a mono-, di- or trialkylsilyl group), a monoalkylamino group or a dialkylamino group having 1 to 40 carbon atoms (hereinafter, sometimes referred to as a mono- or dialkylamino group), and a carbon number of 6 to 60. Aryl group having 6 to 60 carbon atoms, arylalkyl group having 7 to 60 carbon atoms, arylalkoxy group having 7 to 60 carbon atoms, aryl group having 8 to 60 carbon atoms, Ruarukeniru group, arylalkynyl group 8-60 carbon atoms, mono-arylamino group or a diarylamino group having 6 to 60 carbon atoms (hereinafter,
A mono- or diarylamino group), a monovalent heterocyclic compound group having 2 to 60 carbon atoms and a substituent selected from the group consisting of a cyano group, and the aryl group, the aryloxy group, and the arylalkyl group. The arylalkoxy group, arylalkenyl group, arylalkynyl group, mono- or diarylamino group and monovalent heterocyclic compound group may further have a substituent. Here, the alkoxy group having a linear, branched or cyclic alkyl group means that the alkyl group constituting the alkoxy group is
It means a linear, branched or cyclic alkyl group. The alkylthio group having a linear, branched or cyclic alkyl group means that the alkyl group constituting the alkoxy group is a linear, branched or cyclic alkyl group (the same applies hereinafter). . In the above example of Ar ₁ , one structural formula has a plurality of Rs, but they may be the same or different groups, and each is independently selected. Further, the carbon atom of the substituent of Ar ₁ may be replaced with an oxygen atom or a sulfur atom, and one or more hydrogen atoms may be replaced with a fluorine atom. In order to increase the solubility of the polymeric fluorescent substance of the present invention in a solvent, the polymeric fluorescent substance preferably has at least one substituent that is not a hydrogen atom, and the symmetry of the shape of the repeating unit including the substituent is preferred. Preferably, it is small.

In the above formula (2), Ar ₂ has ₂ carbon atoms.
~ 60 monovalent heterocyclic compound group, or 6 to 6 carbon atoms
0 is an aryl group. The monovalent heterocyclic compound group may have a substituent. The aryl group is a linear, branched or cyclic alkyl group having 5 to 20 carbon atoms, an alkoxy group having a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, Alkylthio group having a linear, branched or cyclic alkyl group of -20, mono-, di- or trialkylsilyl group having 1-60 carbon atoms, mono- or dialkylamino group having 1-40 carbon atoms, at least one substitution 6 to 6 carbon atoms having a group
0 aryl group, aryloxy group having 6 to 60 carbon atoms,
Arylalkyl group having 7 to 60 carbon atoms, 7 to 60 carbon atoms
An arylalkoxy group, an arylalkynyl group having 8 to 60 carbon atoms, a monoarylamino group having 6 to 60 carbon atoms,
An aryl group having at least one substituent selected from the group consisting of a diarylamino group having 16 to 60 carbon atoms and a monovalent heterocyclic compound group having 2 to 60 carbon atoms.
The aryloxy group, arylalkyl group, arylalkoxy group, arylalkenyl group, arylalkynyl group, mono- or diarylamino group, and monovalent heterocyclic compound group may further have a substituent.

When Ar ₂ is a monovalent heterocyclic compound group, examples of the substituent which may be present include a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and a substituent having 1 to 20 carbon atoms. An alkoxy group having a linear, branched or cyclic alkyl group; an alkylthio group having a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a mono-, di- or tri- Alkylsilyl group, mono- or dialkylamino group having 1 to 40 carbon atoms, aryl group having 6 to 60 carbon atoms, aryloxy group having 6 to 60 carbon atoms, 7 carbon atoms
An arylalkyl group having 6 to 60 carbon atoms, an arylalkoxy group having 7 to 60 carbon atoms, an arylalkenyl group having 8 to 60 carbon atoms, an arylalkynyl group having 8 to 60 carbon atoms, and 6 carbon atoms
And monovalent or diarylamino groups having from 60 to 60, and monovalent heterocyclic compound groups having 2 to 60 carbon atoms. The aryl group, aryloxy group, arylalkyl group, arylalkoxy group, arylalkenyl group, arylalkynyl group, The mono- or diarylamino group and the monovalent heterocyclic compound group may further have a substituent.

The above Ar_TwoOf the substituents_Threeso
The portion represented is -SiR₆R₇R ₈Part represented by
May be replaced by -CH_TwoRepresented by-
The moiety is -O-, -S- or -SiR₉R_TenRepresented by-
May be replaced by the partThe part represented byMay be replaced by a portion represented by

Here, R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁
Is a group consisting of a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a monovalent heterocyclic compound group having 2 to 20 carbon atoms, and a cyano group. A group selected from the group consisting of the aryl group and the 1
The valent heterocyclic compound group may further have a substituent, and one or more hydrogen atoms of the substituent of Ar ₂ may be replaced by a fluorine atom. When Ar ₂ has a plurality of substituents, they may be the same or different.

X in the above formula (2) is -O-, -S
—, —SiR ₃ R ₄ —, —NR ₅ —, —CO—, —COO
-, -SO _2- represents a group represented by -O-, -S-,
A group represented by —SiR ₃ R ₄ — is preferable, and —O— and —S
A group represented by-is preferable, and more preferably -O
It is a group represented by-. R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, and a monovalent having 2 to 60 carbon atoms. And the aryl group and the heterocyclic compound group may further have a substituent.

Next, specific examples of the aryl group and the monovalent heterocyclic compound group in Ar ₂ will be described. Examples of the aryl group having 6 to 60 carbon atoms include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, and a perylenyl group. A phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable. Moreover, carbon number is 2-60.
A monovalent heterocyclic compound group, that is, a monovalent heterocyclic compound group having 2 to 60 carbon atoms constituting the heterocyclic ring,
A pyrrolyl group, a pyridyl group, a piperazyl group, a quinolyl group,
Quinoxalyl, indolyl, carbazoyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzothienyl, dibenzothienyl, oxadiazolyl, oxazolyl, triazolyl, thiodiazolyl, benzoxazolyl, benzodiazolyl , A silyl group, a benzosilolyl group and the like, and a thienyl group and a pyridyl group are preferred. Here, the monovalent heterocyclic compound group means an atomic group remaining after removing one hydrogen atom from the heterocyclic compound.

Next, in the above example of Ar ₁ , the above formula (2)
Specific examples of the substituents of R and Ar ₂ other than the substituents represented by are shown below. As a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms represented by R of Ar _{1 and} a linear, branched or cyclic alkyl group having 5 to 20 carbon atoms in the substituent of Ar ₂ Is a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,
n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, lauryl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclo Examples include a heptyl group, a cyclooctyl group, a cyclononyl group, and a cyclododecyl group, and a pentyl group, a hexyl group, an octyl group, a decyl group, and a cyclohexyl group are preferable. In addition, as an alkyl group, n-, i
In the case where an example in which a prefix such as so- is not described is given, the example is intended to exemplify all the alkyl groups having a linear or branched structure (the same applies hereinafter).

The carbon number represented by R of Ar ₁ is 1-20.
Examples of the alkoxy group having a linear, branched or cyclic alkyl group and an alkoxy group having a linear, branched or cyclic alkyl group having 5 to 20 carbon atoms in the substituent of Ar ₂ include a methoxy group, Ethoxy group, n-propyloxy group, iso-propyloxy group, n-butoxy group, iso-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, heptyloxy group,
Octyloxy group, nonyloxy group, decyloxy group,
Lauryloxy group, cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloheptyloxy group, and the like,
A pentyloxy group, a hexyloxy group, an octyloxy group, a decyloxy group, and a cyclohexyloxy group are preferred.

The above-mentioned Ar ₁ has 1 to 20 carbon atoms represented by R.
Examples of the alkylthio group having a linear, branched, or cyclic alkyl group having 5 to 20 carbon atoms in the alkoxy group having a linear, branched, or cyclic alkyl group and the substituent of Ar ₂ include a methylthio group, Ethylthio, n-propylthio, iso-propylthio, n-butylthio, iso-butylthio, tert-butylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, laurylthio, cyclo Propylthio group, cyclobutylthio group, cyclopentylthio group, cyclohexylthio group,
Examples include a cycloheptylthio group and the like, a pentylthio group, a hexylthio group, an octylthio group, a decylthio group,
A cyclohexylthio group is preferred.

The mono-, di- or trialkylsilyl group having 1 to 60 carbon atoms includes monomethylsilyl group, dimethylsilyl group, trimethylsilyl group, monoethylsilyl group,
Diethylsilyl group, triethylsilyl group, monopropylsilyl group, dipropylsilyl group, tripropylsilyl group, monobutylsilyl group, dibutylsilyl group, tributylsilyl group, monopentylsilyl group, dipentylsilyl group, tripentylsilyl group, Monohexylsilyl group, dihexylsilyl group, trihexylsilyl group, monoheptylsilyl group, diheptylsilyl group, triheptylsilyl group, monooctylsilyl group, dioctylsilyl group, monooctylsilyl group, dioctylsilyl group, trioctylsilyl Group, monononylsilyl group, dinonylsilyl group, trinonylsilyl group, monodecylsilyl group, didecylsilyl group, tridecylsilyl group, monolaurylsilyl group, dilaurylsilyl group, trilaurylsilyl group, ethyldimethylsilyl group, Dimethylsilyl group, butyldimethylsilyl group, pentyldimethylsilyl group, hexyldimethylsilyl group, heptyldimethylsilyl group, octyldimethylsilyl group, nonyldimethylsilyl group, decyldimethylsilyl group, lauryldimethylsilyl group, and the like. Pentylsilyl group, trihexylsilyl group,
Trioctylsilyl, tridecylsilyl, pentyldimethylsilyl, hexyldimethylsilyl, octyldimethylsilyl, and decyldimethylsilyl are preferred.

The mono- or di-alkylamino group having 1 to 40 carbon atoms includes monomethylamino group, dimethylamino group, monoethylamino group, diethylamino group, monopropylamino group, dipropylamino group, monobutylamino group, dibutylamino group. Group, monopentylamino group, dipentylamino group, monohexylamino group, dihexylamino group, monoheptylamino group, diheptylamino group, monooctylamino group, dioctylamino group, monononylamino group, dinonylamino group, monodecylamino Groups, didecylamino group, monolaurylamino group, dilaurylamino group and the like, and examples thereof include a pentylamino group, a hexylamino group, an octylamino group, a decylamino group, a dipentylamino group, a dihexylamino group, a dioctylamino group, and a didecylamino group It is preferred.

The aryl group having 6 to 60 carbon atoms includes
Phenyl, naphthyl, anthryl, pyrenyl,
Renyl group and the like are exemplified;₁~ C₁₂Alkyl group (C₁
~ C ₁₂Indicates that the number of carbon atoms is 1 to 12. The same applies to
It is like. ), C₁~ C₁₂Alkoxy group, C₆~ C₂₀Ants
May further have a hydroxyl group as a substituent;₁~
C₁₂A phenyl group having an alkoxy group, C₁~ C₁₂Al
A phenyl group having a kill group is preferred.

Examples of the aryloxy group having 6 to 60 carbon atoms include a phenoxy group, a naphthyloxy group, an anthryloxy group and the like, and a C ₁ -C ₁₂ alkyl group, a C ₁ -C _1
It may further have a ₁₂ alkoxy group or a C ₆ -C ₂₀ aryl group as a substituent, and is preferably a phenoxy group having a C ₁ -C ₁₂ alkoxy group or a phenoxy group having a C ₁ -C ₁₂ alkyl group.

As the arylalkyl group having 7 to 60 carbon atoms, a phenyl-C ₁ -C ₁₂ alkyl group, naphthyl-C ₁
-C ₁₂ alkyl group, anthryl -C ₁ -C ₁₂ alkyl groups and the like, having C ₁ -C ₁₂ alkyl group, C ₁ -C ₁₂ alkoxy group, as a substituent a C ₆ -C ₂₀ aryl group even if well, C ₁ -C ₁₂ phenyl -C ₁ -C ₁₂ alkyl group having an alkoxy group, a phenyl -C ₁ -C ₁₂ alkyl group having a C ₁ -C ₁₂ alkyl group.

Examples of the arylalkoxy group having 7 to 60 carbon atoms include a phenyl-C ₁ -C ₁₂ alkoxy group, a naphthyl-C ₁ -C ₁₂ alkoxy group and an anthryl-C ₁ -C ₁₂ alkoxy group. ₁ -C ₁₂ alkyl group, C ₁ ~
C ₁₂ alkoxy group may have as a substituent a C ₆ -C _{2 0} aryl group, a phenyl -C ₁ -C ₁₂ alkoxy group having C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkyl preferably phenyl -C ₁ -C ₁₂ alkoxy group having a group.

Examples of the arylalkenyl group having 8 to 60 carbon atoms include a phenylethenyl group, a naphthylethenyl group, an anthrylethenyl group, a pyrenylethenyl group and the like, and include a C ₁ -C ₁₂ alkyl group and a C ₁ -C ₁₂ alkoxy group. Group, C
₆ -C ₂₀ aryl group may have as a substituent a, phenylethenyl group having phenylethenyl group, phenylethenyl group having C ₁ -C ₁₂ alkoxy group, a C ₁ -C ₁₂ alkyl group Is preferred.

Examples of the arylalkynyl group having 8 to 60 carbon atoms include a phenylethynyl group, a naphthylethynyl group, an anthrylethynyl group, a pyrenylethynyl group and the like, and include a C ₁ -C ₁₂ alkyl group and a C ₁ -C ₁₂ alkoxy group. , C
₆ -C ₂₀ aryl group may have as a substituent a phenyl ethynyl group, phenylethynyl group having C ₁ -C ₁₂ alkoxy group, phenylethynyl group having C ₁ -C ₁₂ alkyl group.

A monoarylamino group having 6 to 60 carbon atoms and
A monophenylamino group, C ₁~ C₁₂Alkyl-
Phenylamino group, mononaphthylamino group, C₁~ C₁₂
And an alkyl-naphthylamino group.₁~ C
₁₂Alkyl group, C₁~ C₁₂Alkoxy group, C₆~ C₂₀Ants
May further have a thiol group as a substituent;₁~
C₁₂Monophenylamino having an alkyl group as a substituent
Group, C₁~ C₁₂Alkyl-phenylamino group is preferred
No.

[0042] As the diarylamino group having 6 to 60 carbon atoms, a diphenylamino group, dinaphthylamino group, phenyl - such naphthylamino group and the like, C ₁ -C ₁₂ alkyl group, C ₁ -C ₁₂ alkoxy group, may have as a substituent a C ₆ -C ₂₀ aryl group, C ₁ -C ₁₂
A diphenylamino group having an alkyl group as a substituent is preferred. However, when Ar ₂ is an aryl group, the diphenylamino group is excluded.

Examples of the monovalent heterocyclic compound having 2 to 60 carbon atoms include pyrrolyl, pyridyl, piperazyl, quinolyl, quinoxalyl, indolyl, carbazoyl, furyl, benzofuryl, dibenzofuryl, Thienyl group, benzothienyl group, dibenzothienyl group, oxadiazolyl group, oxazolyl group, triazolyl group,
Examples thereof include a thiodiazolyl group, a benzooxazolyl group, a benzodiazolyl group, a silolyl group, a benzosilolyl group and the like, and include a C _{1 to} C ₁₂ alkyl group, a C _{1 to} C ₁₂ alkoxy group,
₆ -C ₂₀ aryl group may have as a substituent a, a thienyl group, a thienyl group having C ₁ -C ₁₂ alkyl group, a pyridyl group, pyridyl group having C ₁ -C ₁₂ alkyl group.

Among the substituents of Ar ₁ of the formula ( ₁ ) and Ar ₂ of the formula (2), in the substituent containing an alkyl chain, they may be any of linear, branched or cyclic or a combination thereof. And when it is not linear, for example, an isoamyl group, a 2-ethylhexyl group, a 3,7-
Dimethyloctyl group, cyclohexyl group, 4-C ₁ -C ₁
Examples thereof include a _2- alkylcyclohexyl group. In order to increase the solubility of the polymeric fluorescent substance in the solvent, it is preferable that at least one of the substituents of Ar ₁ and Ar ₂ contains a cyclic or branched alkyl chain. Also, 2
The ends of two alkyl chains may be linked to form a ring. Further, some carbon atoms of the alkyl chain may be replaced by a group containing a hetero atom, and examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom. Further, among the examples of the substituents of Ar ₁ and Ar ₂ , when an aryl group or a monovalent heterocyclic compound group is included in a part thereof, they may further have one or more substituents. .

In the above formula (1), m is 0 or 1, and from the viewpoint that a polymer having a high molecular weight is easily obtained, 1 is obtained.
Is preferred.

R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, and 2 carbon atoms. And a group selected from the group consisting of monovalent heterocyclic compound groups of from 60 to 60, and the aryl group and the monovalent heterocyclic compound group may further have a substituent.

Next, R ₁ and R _{2 in} the formula (1) and R _{3 in the} formula (2)
Specific examples of -R ₅ and R ₆ -R ₁₁ will be described when they are substituents other than a hydrogen atom or a cyano group. Examples of the linear, branched or cyclic alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group and a tert-butyl group. , Pentyl group, hexyl group,
Heptyl, octyl, nonyl, decyl, lauryl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclododecyl, and the like are exemplified. Hexyl, octyl, decyl and cyclohexyl are preferred.

The aryl group having 6 to 60 carbon atoms includes
Phenyl, naphthyl, anthryl, pyrenyl,
Renyl group and the like are exemplified;₁~ C₁₂Alkyl group (C₁
~ C ₁₂Indicates that the number of carbon atoms is 1 to 12. The same applies to
It is like. ), C₁~ C₁₂Alkoxy group, C₆~ C₂₀Ants
A phenyl group as a substituent.
Group, C₁~ C₁₂A phenyl group having an alkyl group is preferred.
New

Examples of the monovalent heterocyclic compound group having 2 to 60 carbon atoms include pyrrolyl, pyridyl, piperazyl, quinolyl, quinoxalyl, indolyl, carbazoyl, furyl, benzofuryl, dibenzofuryl, Thienyl group, benzothienyl group, dibenzothienyl group, oxadiazolyl group, oxazolyl group, triazolyl group,
Examples thereof include a thiodiazolyl group, a benzooxazolyl group, a benzodiazolyl group, a silolyl group, a benzosilolyl group and the like, and include a C _{1 to} C ₁₂ alkyl group, a C _{1 to} C ₁₂ alkoxy group,
₆ -C ₂₀ aryl group may have as a substituent a, a thienyl group, a thienyl group having C ₁ -C ₁₂ alkyl group, a pyridyl group, pyridyl group having C ₁ -C ₁₂ alkyl group.

The terminal group of the polymeric fluorescent substance is protected with a stable group, since if the polymerization active group remains as it is, the light emitting characteristics and life of the device may be reduced. Is also good. Those having a conjugate bond continuous with the conjugate structure of the main chain are preferable, and examples thereof include a structure in which the conjugate structure is bonded to an aryl group or a heterocyclic compound group via a vinylene group. Specific examples include the substituents described in Chemical Formula 10 of JP-A-9-45478.

As a method for synthesizing the polymeric fluorescent substance of the present invention,
When the main chain has a vinylene group, for example, Japanese Unexamined Patent Publication No.
The method described in JP-A-202355 is cited. That is, polymerization by a Wittig reaction such as polymerization of a dialdehyde compound and a diphosphonium salt compound, and polymerization of a dialdehyde compound and a diphosphate compound by a Horner-Wadsworth-Emmons method, or a polymerization of a divinyl compound with a dihalogen compound or a vinyl halogen compound Polymerization by Heck reaction alone, polycondensation of compound having two methyl halide groups by dehydrohalogenation method, polycondensation of compound having two sulfonium bases by sulfonium salt decomposition method, dialdehyde compound and diacetonitrile compound And a method such as polymerization by Knoevenagel reaction. Of these, Wittig disclosed in JP-A-3-244630
Polymerization by reaction, polycondensation by a dehydrohalogenation method, and polycondensation by a sulfonium salt decomposition method are easy to carry out.

When the main chain does not have a vinylene group, for example, a method of polymerizing the corresponding monomer by a Suzuki coupling reaction, a method of polymerizing by a Grignard reaction, a method of polymerizing by a Ni (0) catalyst, FeCl ₃ And the like, a method of electrochemically oxidatively polymerizing, a method of decomposing an intermediate polymer having an appropriate leaving group, and the like.

The polymeric fluorescent substance may contain a repeating unit other than the repeating unit represented by the formula (1) as long as the fluorescent property and the charge transport property are not impaired. Further, the repeating unit represented by the formula (1) or another repeating unit may be linked by a non-conjugated unit, or the repeating unit may include a non-conjugated portion thereof. Examples of the bonding structure include those shown below, a combination of the following and a vinylene group, and a combination of two or more of the following. Here, R is a group selected from the same substituents as described above, and Ar represents a hydrocarbon group having 6 to 60 carbon atoms. Further, the polymeric fluorescent substance of the present invention may be a random, block or graft copolymer, or a polymer having an intermediate structure between them, for example, a random copolymer having a block property. Is also good. From the viewpoint of obtaining a polymeric fluorescent substance having a high quantum yield of fluorescence, a random copolymer having block properties or a block or graft copolymer is preferable to a complete random copolymer. The case where the main chain is branched and there are three or more terminal portions, and dendrimers are also included.

Since light emission from a thin film is used, a polymer fluorescent substance having fluorescence in a solid state is preferably used. As a good solvent for the polymeric fluorescent substance of the present invention, chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene,
Examples include tetralin, decalin, n-butylbenzene, and the like. Although it depends on the structure and molecular weight of the polymeric fluorescent substance, it can be usually dissolved in these solvents in an amount of 0.1% by weight or more.

The polymeric fluorescent substance of the present invention has a number average molecular weight of 1 × 10 ³ to 1 × 10 ⁸ in terms of polystyrene, and the degree of polymerization thereof varies depending on the repeating structure and its ratio. In general, the total number of repeating structures is
Preferably from 20 to 10,000, more preferably from 30 to
It is 10,000, particularly preferably 50 to 5,000.

When the polymer fluorescent substance of the present invention is used as a light emitting material of a polymer LED, its purity affects the light emitting characteristics. Therefore, the monomer before polymerization was purified by a method such as distillation, sublimation purification, and recrystallization. It is preferable to polymerize later,
After the synthesis, it is preferable to carry out a purification treatment such as reprecipitation purification or fractionation by chromatography.

Next, the polymer LED of the present invention will be described. As the structure of the polymer LED of the present invention, at least one is a polymer LED having a light-emitting layer between electrodes consisting of a pair of anodes and cathodes that are transparent or translucent,
The polymeric fluorescent substance of the present invention is contained in the light emitting layer. Further, as the polymer LED of the present invention, a polymer LED provided with an electron transport layer between the cathode and the light emitting layer, a polymer LED provided with a hole transport layer between the anode and the light emitting layer, Polymer LEDs in which an electron transporting layer is provided between a cathode and a light emitting layer and a hole transporting layer is provided between an anode and a light emitting layer are exemplified. For example, the following structures a) to d) are specifically exemplified. a) anode / light-emitting layer / cathode b) anode / hole-transport layer / light-emitting layer / cathode c) anode / light-emitting layer / electron-transport layer / cathode d) anode / hole-transport layer / light-emitting layer / electron-transport layer / cathode (Here, / indicates that the layers are stacked adjacently. The same applies hereinafter.)

Here, the light emitting layer is a layer having a function of emitting light, the hole transporting layer is a layer having a function of transporting holes, and the electron transporting layer is a layer having a function of transporting electrons. It is a layer which has. Note that the electron transport layer and the hole transport layer are collectively referred to as a charge transport layer. The light emitting layer, the hole transporting layer, and the electron transporting layer may be each independently used in two or more layers.

Further, among the charge transport layers provided adjacent to the electrodes, the charge transport layer has a function of improving the charge injection efficiency from the electrodes,
Those having the effect of lowering the drive voltage of the element are generally called a charge injection layer (hole injection layer, electron injection layer) in particular.

Further, in order to improve the adhesion to the electrode and the charge injection from the electrode, the charge injection layer or the insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode.
A thin buffer layer may be inserted at the interface between the charge transport layer and the light emitting layer in order to improve the adhesion at the interface and prevent mixing. The order and number of layers to be stacked and the thickness of each layer can be appropriately used in consideration of luminous efficiency and device life.

In the present invention, a polymer LED provided with a charge injection layer (electron injection layer, hole injection layer) includes a polymer LED provided with a charge injection layer adjacent to a cathode, and a charge LED adjacent to an anode. There is a polymer LED provided with an injection layer.
For example, the following structures e) to p) are specifically mentioned. e) anode / charge injection layer / emission layer / cathode f) anode / emission layer / charge injection layer / cathode g) anode / charge injection layer / emission layer / charge injection layer / cathode h) anode / charge injection layer / hole Transport layer / light emitting layer / cathode i) anode / hole transport layer / light emitting layer / charge injection layer / cathode j) anode / charge injection layer / hole transport layer / light emitting layer / charge injection layer / cathode k) anode / charge Injection layer / light-emitting layer / electron transport layer / cathode l) anode / light-emitting layer / electron transport layer / charge injection layer / cathode m) anode / charge injection layer / light-emitting layer / electron transport layer / charge injection layer / cathode n) anode / Charge injection layer / Hole transport layer / Emitting layer / Electron transport layer / Cathode o) Anode / Hole transport layer / Emitting layer / Electron transport layer / Charge injection layer / Cathode p) Anode / Charge injection layer / Hole transport Layer / light-emitting layer / electron transport layer / charge injection layer / cathode

As a specific example of the charge injection layer, a layer containing a conductive polymer, provided between the anode and the hole transport layer,
A layer containing a material having an ionization potential of an intermediate value between the anode material and the hole transport material contained in the hole transport layer, provided between the cathode and the electron transport layer, and contained in the cathode material and the electron transport layer Examples include a layer containing a material having an electron affinity of an intermediate value between the electron transport material and the like.

When the charge injection layer is a layer containing a conductive polymer, the conductive polymer has an electric conductivity of 10 ⁻⁵ S / cm.
It is preferably at least 10 ³ S / cm, and in order to reduce the leak current between the light emitting pixels, it is 10 ⁻⁵ S / c.
m or more and 10 ² S / cm or less, more preferably 10 ⁻⁵ S / cm.
cm or more and 10 ¹ S / cm or less is more preferable. Usually, the electric conductivity of the conductive polymer is 10 ^-5 S / cm or more and 10
^The conductive polymer is doped with an appropriate amount of ions in order to make it ³ S / cm or less.

The types of ions to be doped are anions for the hole injection layer and cations for the electron injection layer.
Examples of anions include polystyrenesulfonate, alkylbenzenesulfonate, and camphorsulfonate, and examples of cations include lithium, sodium, potassium, and tetrabutylammonium. The thickness of the charge injection layer is, for example, 1 nm to 100 nm, and preferably 2 nm to 50 nm.

The material used for the charge injection layer may be appropriately selected depending on the materials of the electrodes and the adjacent layers. Polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylenevinylene and its derivatives, Thienylene vinylene and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, conductive polymers such as polymers having an aromatic amine structure in the main chain or side chain, metal phthalocyanine (copper phthalocyanine, etc.), carbon, etc. Is exemplified.

The insulating layer having a thickness of 2 nm or less has a function of facilitating charge injection. Examples of the material for the insulating layer include metal fluorides, metal oxides, and organic insulating materials. Polymer LE provided with an insulating layer having a thickness of 2 nm or less
Examples of D include a polymer LED provided with an insulating layer having a thickness of 2 nm or less adjacent to a cathode, and a polymer LED provided with an insulating layer having a thickness of 2 nm or less adjacent to an anode.

Specific examples include the following structures q) to ab). q) Anode / Insulating layer having a thickness of 2 nm or less / Emitting layer / Cathode r) Anode / Emitting layer / Insulating layer having a thickness of 2 nm or less s) Anode / Insulating layer having a thickness of 2 nm or less / Emitting layer / 2n thickness
m) Insulating layer / cathode t or less t) Anode / insulating layer / thickness 2 nm or less / hole transporting layer / light emitting layer / cathode u) Anode / hole transporting layer / luminescent layer / insulating layer / thickness 2 nm or less / cathode v A) Anode / insulating layer having a thickness of 2 nm or less / hole transporting layer / light emitting layer / insulating layer having a thickness of 2 nm or less / cathode w) anode / insulating layer having a thickness of 2 nm or less / emitting layer / electron transporting layer / cathode x) Anode / light-emitting layer / electron transport layer / insulating layer with thickness of 2 nm or less / cathode y) anode / insulating layer with thickness of 2 nm or less / light-emitting layer / electron transport layer / insulating layer with thickness of 2 nm or less / cathode z) anode / Aa) anode / hole transport layer / light emitting layer / electron transport layer / film thickness 2n; insulating layer having a thickness of 2 nm or less / hole transport layer / light emitting layer / electron transport layer / cathode
a) Insulating layer / Hole transporting layer / Emitting layer / Electron transporting layer / Insulating layer having a thickness of 2 nm or less / Cathode

When a polymer LED is prepared by using these organic solvent-soluble polymer fluorescent materials to form a film from a solution, it is only necessary to remove the solvent by drying after coating this solution. The same method can be applied to a case where a transport material and a light-emitting material are mixed, which is very advantageous in production. As a method of forming a film from a solution, a spin coating method, a casting method, a microgravure coating method,
Coating methods such as gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, and inkjet printing can be used.

The optimum value of the thickness of the light emitting layer varies depending on the material used, and may be selected so that the driving voltage and the luminous efficiency have appropriate values. For example, the thickness is 1 nm to 1 μm, preferably 2 nm to 500 nm. And more preferably 5 nm to 200 nm.

In the polymer LED of the present invention, a light emitting material other than the above polymer fluorescent substance may be mixed and used in the light emitting layer. In the polymer LED of the present invention, a light-emitting layer containing a light-emitting material other than the polymer fluorescent substance may be laminated with a light-emitting layer containing the polymer fluorescent substance. As the light emitting material, known materials can be used. Examples of low molecular weight compounds include naphthalene derivatives, anthracene or derivatives thereof, perylene or derivatives thereof, polymethine-based, xanthene-based, coumarin-based, cyanine-based dyes, metal complexes of 8-hydroxyquinoline or derivatives thereof, and aromatic amines. , Tetraphenylcyclopentadiene or a derivative thereof, or tetraphenylbutadiene or a derivative thereof can be used. Specifically, for example, Japanese Patent Application Laid-Open Nos.
Known ones such as those described in 194393 can be used.

When the polymer LED of the present invention has a hole transporting layer, the hole transporting material used includes polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and an aromatic amine in a side chain or a main chain. Polysiloxane derivative, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or its derivative, polythiophene or its derivative, polypyrrole or its derivative, poly (p-phenylenevinylene) or its derivative, or poly (2, 5-thienylenevinylene) or a derivative thereof.

Specifically, examples of the hole transport material include JP-A-63-70257, JP-A-63-175860, JP-A-2-135359, and JP-A-2-13536.
No. 1, No. 2-209988, No. 3-3799
No. 2, JP-A-3-152184, etc. are exemplified.

Among them, as a hole transporting material used for the hole transporting layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or Derivatives thereof, polythiophene or derivatives thereof, poly (p-phenylenevinylene)
Or a derivative thereof, or a polymer hole transporting material such as poly (2,5-thienylenevinylene) or a derivative thereof, and more preferably polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof,
A polysiloxane derivative having an aromatic amine in the side chain or main chain. In the case of a low-molecular-weight hole transport material, it is preferable to use the material by dispersing it in a polymer binder.

Polyvinyl carbazole or a derivative thereof can be obtained, for example, from a vinyl monomer by cation polymerization or radical polymerization.

As the polysilane or a derivative thereof,
Chemical Review (Chem. Rev.) Vol. 89,
1359 (1989), British Patent GB230019
Compounds described in No. 6 published specification are exemplified. Although the synthesis methods described above can be used as the synthesis method, the Kipping method is particularly preferably used.

Polysiloxane or a derivative thereof has almost no hole transporting property in the siloxane skeleton structure.
Those having the structure of the low-molecular-weight hole transporting material in the side chain or main chain are preferably used. Particularly, those having a hole transporting aromatic amine in the side chain or main chain are exemplified.

The method for forming the hole transport layer is not limited.
In the case of the low-molecular-weight hole transport material, a method of forming a film from a mixed solution with a polymer binder is exemplified. In the case of a polymer hole transport material, a method of forming a film from a solution is exemplified.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve the hole transport material.
As the solvent, chloroform, methylene chloride, chlorine solvents such as dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, acetone, ketone solvents such as methyl ethyl ketone,
Ester solvents such as ethyl acetate, butyl acetate and ethyl cellosolve acetate are exemplified.

As a method for forming a film from a solution, spin coating from a solution, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, and the like. Method, screen printing method, flexographic printing method,
A coating method such as an offset printing method and an inkjet printing method can be used.

As the polymer binder to be mixed, those which do not extremely inhibit charge transport are preferable, and those which do not strongly absorb visible light are preferably used. Examples of the polymer binder include polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

The optimum value of the thickness of the hole transport layer depends on the material used, and may be selected so that the drive voltage and the luminous efficiency are appropriate. Is necessary, and if it is too thick,
The driving voltage of the device is undesirably high. Therefore, the thickness of the hole transport layer is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

When the polymer LED of the present invention has an electron transporting layer, known electron transporting materials can be used, and oxadiazole derivatives, anthraquinodimethane or its derivatives, benzoquinone or its derivatives, Naphthoquinone or a derivative thereof, anthraquinone or a derivative thereof, tetracyanoanthraquinodimethane or a derivative thereof, a fluorenone derivative, diphenyldicyanoethylene or a derivative thereof, a diphenoquinone derivative, or a metal complex of 8-hydroxyquinoline or a derivative thereof, polyquinoline or a derivative thereof, Examples thereof include polyquinoxaline or a derivative thereof, polyfluorene or a derivative thereof, and the like.

Specifically, JP-A-63-70257, JP-A-63-175860, and JP-A-2-1353
Nos. 59, 2-135361, 2-209
988, 3-37992, 3-152
No. 184 is exemplified.

Of these, oxadiazole derivatives,
Benzoquinone or a derivative thereof, anthraquinone or a derivative thereof, a metal complex of 8-hydroxyquinoline or a derivative thereof, polyquinoline or a derivative thereof, polyquinoxaline or a derivative thereof, polyfluorene or a derivative thereof are preferable, and 2- (4-biphenylyl) -5 is preferable. -(4-t-butylphenyl) -1,
3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferred.

The method for forming the electron transporting layer is not particularly limited. For the low molecular weight electron transporting material, a vacuum evaporation method from a powder or a method by film formation from a solution or a molten state is used. In the examples, a method by film formation from a solution or a molten state is exemplified. When forming a film from a solution or a molten state, a polymer binder may be used in combination.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve the electron transport material and / or the polymer binder. As the solvent, chloroform, methylene chloride, chlorine solvents such as dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, acetone, ketone solvents such as methyl ethyl ketone, ethyl acetate, butyl acetate, Ester solvents such as ethyl cellosolve acetate are exemplified.

The film forming method from the solution or molten state includes spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, and the like. A coating method such as a printing method, a screen printing method, a flexographic printing method, an offset printing method, and an inkjet printing method can be used.

As the polymer binder to be mixed, those which do not extremely inhibit charge transport are preferable, and those which do not strongly absorb visible light are suitably used. Examples of the polymer binder include poly (N-vinylcarbazole), polyaniline or a derivative thereof, polythiophene or a derivative thereof, poly (p-phenylenevinylene) or a derivative thereof, poly (2,5-thienylenevinylene) or a derivative thereof, and polycarbonate. , Polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, or polysiloxane.

The optimal value of the film thickness of the electron transporting layer depends on the material used, and may be selected so that the driving voltage and the luminous efficiency have appropriate values. Necessary and too thick,
The driving voltage of the device is undesirably high. Therefore, the film thickness of the electron transport layer is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

The substrate for forming the polymer LED of the present invention comprises:
Any material that does not change when an electrode is formed and an organic layer is formed may be used, and examples thereof include glass, plastic, a polymer film, and a silicon substrate. In the case of an opaque substrate, the opposite electrode is preferably transparent or translucent.

In the present invention, the anode side is preferably transparent or translucent. As the material of the anode, a conductive metal oxide film, a translucent metal thin film, or the like is used. Specifically, a film (NESA) formed using a conductive glass made of indium oxide, zinc oxide, tin oxide, or a complex thereof, such as indium tin oxide (ITO) or indium zinc oxide.
Etc.), gold, platinum, silver, copper and the like are used, and ITO, indium / zinc / oxide, and tin oxide are preferable. Examples of the manufacturing method include a vacuum evaporation method, a sputtering method, an ion plating method, and a plating method. Also,
As the anode, an organic transparent conductive film such as polyaniline or a derivative thereof and polythiophene or a derivative thereof may be used. The thickness of the anode can be appropriately selected in consideration of light transmittance and electric conductivity.
μm, and more preferably 50 nm to 500 nm. Also, on the anode, to facilitate charge injection,
A layer made of a phthalocyanine derivative, a conductive polymer, carbon, or the like, or a layer made of a metal oxide, a metal fluoride, an organic insulating material, or the like and having an average thickness of 2 nm or less may be provided.

As a material for the cathode used in the polymer LED of the present invention, a material having a small work function is preferable. For example,
Lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium,
Metals such as samarium, europium, terbium, ytterbium, and two or more alloys thereof, or one or more thereof, and gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten,
An alloy with one or more of tin, graphite, a graphite intercalation compound, or the like is used. Examples of alloys include:
Magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, calcium-
Aluminum alloy and the like can be mentioned. The cathode may have a laminated structure of two or more layers. The thickness of the cathode can be appropriately selected in consideration of electric conductivity and durability, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm.
μm, and more preferably 50 nm to 500 nm.

As a method for manufacturing the cathode, a vacuum evaporation method, a sputtering method, a lamination method for thermocompression bonding a metal thin film, and the like are used. Further, a layer made of a conductive polymer or a layer made of a metal oxide, a metal fluoride, an organic insulating material, or the like having an average thickness of 2 nm or less may be provided between the cathode and the organic material layer. A protective layer for protecting the polymer LED may be provided. In order to use the polymer LED stably for a long time, it is preferable to attach a protective layer and / or a protective cover to protect the element from the outside.

As the protective layer, polymer compounds, metal oxides, metal fluorides, metal borides and the like can be used. Further, as the protective cover, a glass plate, a plastic plate having a surface subjected to a low water-permeability treatment, or the like can be used, and a method in which the cover is bonded to the element substrate with a heat effect resin or a photocurable resin and hermetically sealed is preferable. Used for If the space is maintained by using the spacer, it is easy to prevent the element from being damaged. By enclosing an inert gas such as nitrogen or argon in the space, oxidation of the cathode can be prevented. Makes it easier to prevent the element from damaging the element. It is preferable to take any one or more of these measures.

To obtain planar light emission using the polymer LED of the present invention, a planar anode and a planar cathode may be arranged so as to overlap. Further, in order to obtain patterned light emission, a method in which a mask having a patterned window provided on the surface of the planar light emitting element is provided. There is a method of emitting light, a method of forming one or both of an anode and a cathode in a pattern. By forming a pattern by any of these methods and arranging some electrodes so that they can be independently turned on / off, a segment type display element capable of displaying numbers, characters, simple symbols, and the like can be obtained.
Further, in order to form a dot matrix element, both the anode and the cathode may be formed in a stripe shape and arranged orthogonally. A partial color display and a multi-color display can be achieved by a method of separately applying a plurality of types of polymer phosphors having different emission colors or a method of using a color filter or a fluorescence conversion filter. The dot matrix element can be driven passively or may be driven actively in combination with a TFT or the like. These display elements can be used as display devices for computers, televisions, mobile terminals, mobile phones, car navigation systems, viewfinders of video cameras, and the like. Further, the planar light emitting element is a thin self-luminous element and can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source or a display device.

[0096]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Here, as 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.

Example 1 <Synthesis of polymeric fluorescent substance 1> After dissolving 2.1 g of 2- {4 ′-(3,7-dimethyloctyloxy) phenyl} oxy-p-xylylenedibromide in 120 g of dry THF, The system was purged with nitrogen by bubbling with nitrogen gas.
A solution prepared by dissolving 2.7 g of potassium t-butoxide in 30 ml of dry THF was added dropwise to this solution at room temperature. After the addition, the reaction was continued at room temperature for 7 hours. Acetic acid was added to the reaction solution to neutralize it, and then poured into methanol, and the generated precipitate was collected. The precipitate was washed with ethanol and dried under reduced pressure to obtain a polymer 0.6.
g was obtained. Next, this polymer was dissolved in chloroform. This solution was poured into ethanol, and the generated precipitate was collected. The precipitate was washed with ethanol and dried under reduced pressure to obtain 0.5 g of a polymer. The obtained polymer is called polymeric fluorescent substance 1.

The number average molecular weight in terms of polystyrene of the polymeric fluorescent substance 1 was 5.9 × 10 ⁴ . <Measurement of Absorption Spectrum and Fluorescence Spectrum and Evaluation of Fluorescence Intensity> The polymeric fluorescent substance 1 was easily dissolved in chloroform. The 0.2% chloroform solution was spin-coated on a quartz plate to form a polymer thin film. The ultraviolet-visible absorption spectrum and the fluorescence spectrum of this thin film were measured using a self-recording spectrophotometer UV365 manufactured by Shimadzu Corporation and a fluorescence spectrophotometer 850 manufactured by Hitachi, Ltd., respectively. For the calculation of the quantum yield of fluorescence, a fluorescence spectrum when excited at 410 nm was used. The fluorescence intensity was determined as a relative value by dividing the area of the fluorescence spectrum plotted by taking the wave number on the horizontal axis by the absorbance at 410 nm. Table 1 shows the results.

Comparative Example 1 <Synthesis of polymeric fluorescent substance 2> 2-Methoxy-5- (2-ethylhexyloxy) -p-xylylene dichloride 2.3
g was dissolved in 400 g of dry THF, and the system was purged with nitrogen by bubbling with nitrogen gas. To this solution, 4.7 g of potassium t-butoxide was previously added in dry THF.
A solution dissolved in 70 ml was added dropwise at room temperature. After dripping,
The reaction was continued at room temperature for 15 hours. In this reaction solution,
After adding acetic acid and neutralizing, pour into methanol,
The resulting precipitate was collected. The precipitate was washed with ethanol and dried under reduced pressure to obtain 1.0 g of a polymer. Next, this polymer was dissolved in THF. This solution was poured into ethanol, and the generated precipitate was collected. The precipitate was washed with ethanol and dried under reduced pressure to obtain 0.8 g of a polymer. The obtained polymer is called polymeric fluorescent substance 2. The number average molecular weight in terms of polystyrene of the polymeric fluorescent substance 2 is 1.8.
× 10 ⁵ .

<Measurement of Absorption Spectrum and Fluorescence Spectrum and Evaluation of Quantum Yield of Fluorescence> Evaluation was performed in the same manner as in Example 1 except that polymeric fluorescent substance 2 was used instead of polymeric fluorescent substance 1. Table 1 shows the results. As shown in Table 1, the fluorescence of polymeric fluorescent substance 1 (Example 1) was stronger than that of polymeric fluorescent substance 2 (Comparative Example 1).

[0101]

[Table 1]

Example 2 <Preparation and evaluation of element>
A 50 nm-thick film was formed by spin coating using a solution of poly (ethylenedioxythiophene) / polystyrenesulfonic acid (Baytron, Baytron) on a glass substrate provided with an ITO film having a thickness of 1 mm.
Dry at 20 ° C. for 10 minutes. Next, a 60 nm-thick film was formed by spin coating using a 0.45 wt% chloroform solution of the polymeric fluorescent substance 1. Further, this was dried under reduced pressure at 80 ° C. for 1 hour, and then, as a cathode buffer layer, lithium fluoride was equivalent to 0.4 nm, and as a cathode, calcium was deposited at 25 nm, and then aluminum was deposited at 40 nm to produce a polymer LED. . The degree of vacuum at the time of vapor deposition was 1 to 8 × 10 ⁻⁶ Torr in all cases. By applying a voltage to the obtained device, EL light emission from the polymeric fluorescent substance 1 was obtained. The light emission starting voltage is about 4V,
The luminous efficiency was a maximum of about 0.5 cd / A. The EL peak wavelength almost coincided with the fluorescence peak wavelength of the thin film of the polymer fluorescent substance 1, and EL emission from the polymer fluorescent substance 1 was confirmed.

[0103]

The polymeric fluorescent substance of the present invention has strong fluorescence. Also, a polymer LED using the polymer phosphor
Since it is easy to produce and has high luminous efficiency, it can be preferably used as devices such as a planar light source as a backlight and a flat panel display.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masamitsu Ishibi 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd. F-term (reference) 3K007 AB03 BA06 EB00 FA01 4J032 BA01 BA02 BA07 BA12 BA17 BB03 BB06 CA02 CA03 CA04 CA06 CA07 CA12 CA33 CA43 CA45 CA62 CB01 CB03 CB08 CG01 CG03 CG06 5F041 AA03 CA45 CB03 FF11

Claims (7)

[Claims] 1. A polymeric fluorescent substance which has visible fluorescence in a solid state and has a polystyrene-equivalent number average molecular weight of 1 × 10 ³ to 1 × 10 ⁸ , and is represented by the following formula (1): A polymeric fluorescent substance comprising one or more kinds of units, and the total of those repeating units is more than 9 mol% and not more than 100 mol% of all repeating units. -Ar _1- (CR ₁ = CR ₂ ) _m- (1) [where Ar ₁ is an arylene group having 6 to 60 carbon atoms or a divalent complex having 2 to 60 carbon atoms. A ring compound group having at least one substituent represented by the following formula (2). m is 0 or 1. R
₁ and R ₂ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms;
And a group selected from the group consisting of an aryl group, a monovalent heterocyclic compound group having 2 to 60 carbon atoms and a cyano group. -X-Ar ₂ (2) (where X is -O-, -S-, -SiR ₃ R ₄ -,-
And a group represented by NR ₅ —, —CO—, —COO—, or —SO ₂ —. Here, R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms and 2 to 60 carbon atoms. And a group selected from the group consisting of monovalent heterocyclic compound groups. Ar ₂ has 2 to 60 carbon atoms.
A monovalent heterocyclic compound group, or an aryl group having 6 to 60 carbon atoms, a linear, branched or cyclic alkyl group having 5 to 20 carbon atoms, a linear chain having 1 to 20 carbon atoms An alkoxy group having a branched or cyclic alkyl group, a straight-chain having 1 to 20 carbon atoms, an alkylthio group having a branched or cyclic alkyl group, a mono-, di- or trialkylsilyl group having 1 to 60 carbon atoms, A mono- or dialkylamino group having 1 to 40 carbon atoms, an aryl group having 6 to 60 carbon atoms having at least one substituent, an aryloxy group having 6 to 60 carbon atoms, an arylalkyl group having 7 to 60 carbon atoms, carbon number 7-60 arylalkoxy group, carbon number 8
Arylalkenyl group having 6 to 60 carbon atoms, monoarylamino group having 6 to 60 carbon atoms, diarylamino group having 16 to 60 carbon atoms, and monovalent heterocyclic compound having 2 to 60 carbon atoms An aryl group having at least one substituent selected from the group consisting of groups. )] 2. In the general formula (2), X is -O-,-
S-, or -SiR ₃ R ₄ - is that wherein a group represented by claim 1 polymeric fluorescent substance according. 3. A polymer light emitting device having at least a light emitting layer between a pair of anodes and cathodes, at least one of which is transparent or translucent, wherein the light emitting layer is the polymer fluorescent light according to claim 1 or 2. A polymer light-emitting device comprising a body. 4. A planar light source using the polymer light emitting device according to claim 3. 5. A segment display device using the polymer light emitting device according to claim 3. 6. A dot matrix display device using the polymer light emitting device according to claim 3. 7. A liquid crystal display device comprising the polymer light emitting device according to claim 3 as a backlight.