WO2005052022A1 - Copolymer, polymer composition and polymer light-emitting device - Google Patents

Abstract

Disclosed is a copolymer having two or more kinds of repeating units selected from the group consisting of arylene groups, divalent heterocyclic groups and divalent aromatic amine groups. The ratio of copolymer molecules having a molecular weight of not more than 1 × 105 in terms of polystyrene is not more than 5.0 weight%, and this copolymer is fluorescent in the solid state. When such a copolymer is used in a device, the luminous efficiency of the device can be improved further.

Description

 Polymer Copolymer, polymer composition and polymer light emitting device

Technical field

 The present invention relates to a copolymer, a polymer composition, and a polymer light-emitting device (hereinafter, may be referred to as a polymer LED).

Background art

Copolymers having an aromatic ring in the main chain have been studied in various ways because they are soluble in a solvent and can form a light-emitting layer in a light-emitting element by a coating method. For example, a copolymer composed of two types of fluorene repeating units ( US2003Z 0143429 A1) is disclosed. In this case, 10% by weight or more of the molecules in the copolymer are molecules having a molecular weight of 1 × 10 ⁵ or less. When a copolymer having an aromatic ring in the main chain is used as a material for a light emitting layer of a polymer LED, it is required that the device has high luminous efficiency, but that of the above copolymer is still insufficient. Was.

Disclosure of the invention

 An object of the present invention is to provide a copolymer which can further increase the luminous efficiency of the device when used in the device.

 The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a copolymer having an aromatic ring in the main chain, and the proportion of molecules having a specific molecular weight or less in the copolymer molecules is equal to or less than a specific ratio. The present inventors have found that when a novel copolymer is used as a material for a light-emitting layer of a polymer LED, it provides an element having high luminous efficiency, and completed the present invention.

That is, the present invention relates to a copolymer having two or more types of repeating units selected from the group consisting of arylene groups, divalent heterocyclic groups, and divalent aromatic amine groups. It relates to a copolymer which has a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene in a polymer molecule of 5.0% by weight or less and emits fluorescence in a solid state.

BEST MODE FOR CARRYING OUT THE INVENTION

The copolymer of the present invention comprises an arylene group, a divalent heterocyclic group, and a divalent aromatic amine group. And a copolymer having two or more types of repeating units selected from the group consisting of: Further, the copolymer of the present invention is a copolymer having two or more types of repeating units selected from the group consisting of an arylene group and a divalent heterocyclic group. In the present invention, the ratio of the molecule having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene in the copolymer molecule is 5.0% by weight or less, and the copolymer emits fluorescence in a solid state. It is characterized by the following. Note that “emitting fluorescence” means that when a compound absorbs excitation energy such as light or electric energy, the compound emits light through an excited “singlet” state.

The ratio (percentage by weight) of the molecules having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene in the copolymer molecules was determined by size exclusion chromatography (hereinafter sometimes referred to as SEC) to obtain a molecular weight of 1 × 10 5. and the integral value in the chromatogram of the components eluted prior to ⁵ elution time of polystyrene standard sample by measuring the integral value in the chromatogram of the components eluted after the elution time of polystyrene standard samples having a molecular weight of 1 X 10 ⁵ It can be calculated. Even if there is no exact molecular weight 1 X 1 0 ⁵ polystyrene standard samples, suitable two or more molecular weight, by using a polystyrene standard sample, more molecular weight to a normal method such as inner揷法1 X 1 0 ⁵ The elution time of the polystyrene standard sample can be obtained.

In the present invention, the proportion (weight percentage) of molecules having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene determined as described above is 5.0% by weight or less, and preferably 2.0% by weight or less. .

Preferably the number average molecular weight in terms of polystyrene of the copolymer of the present invention (Mn) of in the range of ^{2 X 10 5 ~ 7 X 1} 0 5, 2. in the range of ^{5 X 10 5 ~ 6 X 1} 0 5 More preferably, it is more preferably in the range of ³ × 10 ⁵ to 6 × 10 ⁵ . If the Mn is too small, the proportion (weight percentage) of molecules having a molecular weight of 2 × 10 ⁵ or less in terms of polystyrene tends to increase, and the efficiency of the element tends to decrease. Efficiency tends to be lower when the value is lower.

If the weight average molecular weight (Mw) in terms of polystyrene of the copolymer of the present invention is too large, the viscosity of the coating liquid will be too high, and it may be difficult to produce an industrial thin film by a coating method. Therefore, the weight average molecular weight in terms of polystyrene of the copolymer of the present invention is preferably 1 × 10 ⁶ or less, more preferably 9 × 10 ⁵ or less. Mn and Mw can be determined by a conventional method using size exclusion chromatography and using a standard sample of polystyrene as a standard of molecular weight.

 The copolymer of the present invention has, as a repeating unit, an arylene group, a divalent heterocyclic group, and a Z or divalent aromatic amine group.

 Here, the arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon, and two or more independent benzene rings or condensed rings are bonded directly or via a group such as vinylene. Things are also included. The arylene group may have a substituent.

 The carbon number of the portion of the arylene group excluding the substituent is usually about 6 to 60, and the total carbon number including the substituent of the arylene group is usually about 6 to 100.

Specific examples of arylene groups include phenylene, fluorenediyl, biphenylene, terphenylene, naphthalenediyl, anthracenediyl, phenanthrene, pentalenediyl, indenzyl, heptadienyl, and indacene. Examples thereof include a diyl group, a triphenylenediyl group, a binaphthyldiyl group, a phenylnaphthylenediyl group, a stilbenzyl group, a 3,3′-alkoxystilbenzyl group, and a phenylene group and a fluorenediyl group.

 Examples of the phenylene group include the following.

Examples of the fluorenediyl group include the following.

In the formula, R is independently a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an alkylsilyl group, an alkylamino group, an aryl group, an aryloxy group, an arylaryl group, an arylamino group, an arylalkyl group, Examples thereof include an arylalkoxy group, an arylalkylsilyl group, an arylalkylamino group, a monovalent heterocyclic group and a cyano group. In the above figure, one group has a plurality of Rs, which may be the same or different, or may be linked to each other to form a ring.

 Among them, those represented by the above 3 are preferable, and those represented by the following formula (1) are more preferable.

(1)

In the formula, and R ₂ each independently represent a hydrogen atom, an alkyl group, an aryl group or a monovalent heterocyclic group. R ₃ and R ₄ are each independently an alkyl group, an alkoxy group, an alkylthio group, an alkylsilyl group, an alkylamino group, an aryl group, an aryloxy group, an arylsilyl group, an arylamino group, an arylalkyl group, an arylalkoxy group, or Represents a reelalkylsilyl group, an arylalkylamino group, a monovalent heterocyclic group or a cyano group. m and n each independently represent an integer of 0-3. When a plurality of R ₃ and R ₄ are present, they may be the same or different. Also, two or more of R ₂ , R ₃ and R ₄ may be linked to each other to form a ring. Also, and R ₂ are preferably an alkyl group, aryl group or monovalent heterocyclic group, and R ₃ and R ₄ are preferably an alkyl group or an alkoxy group. Further, the divalent heterocyclic group means an atomic group obtained by removing two hydrogen atoms from a heterocyclic compound, and may have a substituent. The carbon number of the portion excluding the substituent in the divalent heterocyclic group is usually about 4 to 60, and the total carbon number including the substituent of the divalent heterocyclic group is usually 4 to 100. It is about.

 Examples of the divalent heterocyclic group include a 6-membered heterocyclic group containing a hetero atom, a group having a fluorene structure containing a hetero atom, a 5-membered heterocyclic group containing a hetero atom, and a 5-membered ring containing a hetero atom. Or a fused heterocyclic group having a 6-membered heterocyclic ring, a 5-membered heterocyclic group containing a heteroatom, a dimer or an oligomer bonded to the α-position of the heteroatom to form a dimer or oligomer, a heteroatom And a 5-membered complex ring group containing a group bonded to the phenyl group at the α-position of the hetero atom. Heteroatoms include nitrogen, oxygen, sulfur, silicon, and selenium, with nitrogen, oxygen, and sulfur being preferred. In the case of a 6-membered heterocyclic group containing a hetero atom, the hetero atom is preferably nitrogen.

Examples of the 6-membered heterocyclic group containing a hetero atom include the following groups.

 11 12 13

Examples of groups having a fluorene structure containing a hetero atom include the following groups

 25 26

 27 28

Examples of the 5-membered heterocyclic group containing a hetero atom include the following groups <

Examples of the condensed heterocyclic group having a 5- or 6-membered heterocyclic ring containing a hetero atom include the following groups.

 42

Examples of the group which is a 5-membered heterocyclic group containing a hetero atom and which is bonded at the α-position of the hetero atom to form a dimer or an oligomer include the following groups.

Examples of a 5-membered heterocyclic group containing a hetero atom that is bonded to the phenyl group at the α-position of the hetero atom include the following structures.

Here, R is independently a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an alkylsilyl group, an alkylamino group, an aryl group, an aryloxy group, an arylsilyl group, an arylamino group, an arylalkyl group, Examples include arylalkoxy, arylalkylsilyl, arylalkylamino, monovalent heterocyclic and cyano groups. It is. In the above figure, one group has a plurality of Rs, but these may be the same or different, or may be linked to each other to form a ring.

 In the above arylene group and divalent heterocyclic group, the alkyl group may be linear, branched or cyclic, and usually has about 1 to 20 carbon atoms. Specifically, a methyl group, an ethyl group , Propyl, i-propyl, butyl, i-butyl, t-butyl, pentyl, isoamyl, hexyl, cyclohexyl, heptyl, octyl, 2-ethylhexyl , Nonyl, decyl, 3,7-dimethyloctyl, lauryl and the like.

Among the alkyl groups in R ₂ , R ₃ and R ₄ of the formula (1), pentyl group, isoamyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group, 3,7-dimethyloctyl Groups are preferred.

 The alkoxy group may be linear, branched or cyclic, and usually has about 1 to about 20 carbon atoms. Specifically, a methoxy group, an ethoxy group, a propyloxy group, an i-propyloxy group, and a butoxy group , Butoxy, t-butoxy, pentyloxy, isoamyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, 3,7- Examples thereof include a dimethyloxy group and a lauryloxy group.

Among the alkoxy groups for R ₃ and R ₄ in the formula (1), pentyloxy group, isoamyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, decyloxy group, and 3,7-dimethyloctyloxy group Groups are preferred.

 The alkylthio group may be straight-chain: branched or cyclic, and usually has about 1 to 20 carbon atoms. Specifically, methylthio, ethylthio, propylthio, i-propylthio, butylthio, i-butylthio, t-butylthio, pentylthio, hexylthio, cyclohexylthio, heptylthio, octylthio, 2-ethylhexylthio, nonylthio, decylthio, 3,7-dimethyloctylthio And a diarylthio group.

Among the alkylthio groups represented by R ₃ and R ₄ in the formula (1), a pentylthio group, an isoamylthio group, a hexylthio group, an octylthio group, a 2-ethylhexylthio group, A luthio group and a 3,7-dimethyloctylthio group are preferred.

 The alkylsilyl group may be linear, branched or cyclic, and usually has about 1 to 60 carbon atoms.Specifically, methylsilyl, ethylsilyl, propylsilyl, i-propylsilyl, butylsilyl, i-butylsilyl, t-butylsilyl, pentylsilyl, hexylsilyl, cyclohexylsilyl, heptylsilyl, octylsilyl, 2-ethylhexylsilyl, nonylsilyl, decylsilyl, 3,7-dimethylo Octylsilyl, laurylsilyl, trimethylsilyl, ethylmethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, t-butyldimethylsilyl, pentyldimethylsilyl, hexyldimethylsilyl , Heptyl jime Lucylyl, octyldimethylsilyl, 2-ethylhexyldimethylsilyl, nonyldimethylsilyl, decyldimethylsilyl, 3,7-dimethyloctyl-dimethylsilyl, lauryldimethylsilyl, etc. Can be

Among the alkylsilyl groups for R ₃ and R ₄ in the formula (1), there are pentylsilyl group, isoamylsilyl group, hexylsilyl group, octylsilyl group, 2-ethylhexylsilyl group, decylsilyl group, and 3,7-dimethylo group. Octylsilyl, pentyldimethylsilyl, isoamyldimethylsilyl, hexyldimethylsilyl, octyldimethylsilyl, 2-ethylhexyl-dimethylsilyl, decyldimethylsilyl, 3,7-dimethyloctyl A rudimethylsilyl group is preferred.

The alkylamino group may be linear, branched or cyclic, may be a monoalkylamino group or a dialkylamino group, and usually has about 1 to 40 carbon atoms. Specifically, a methylamino group, a dimethylamino group, Ethylamino, acetylamino, propylamino, i-propylamino, butylamino, i-butylamino, t-butylamino, pentylamino, hexylamino, cyclohexylamino, heptylamino, octylamino, 2 —Edylhexylamino, nonylamino, decylamino, 3,7-dimethyloctylamino, laurylamino and the like. Among the alkylamino groups represented by R ₃ and R ₄ in the formula (1), pentylamino, isoamylamino, hexylamino, octylamino, and 2-ethylhexylamino And a decylamino group and a 3,7-dimethyloctylamino group are preferred.

§ Li Ichiru group has a carbon number of usually 6 to about 60, specifically, phenyl group, C ~ C _{l 2} alkoxy phenylalanine group, ~ Ji alkylphenyl group, 1-naphthyl group, 2 - such as naphthyl group and the like, C, -C ₁₂ alkoxy phenylalanine group, C, ~C, ₂ Arukirufue alkenyl groups are preferred.

Here, C, -C, ₂ alkyl represents an alkyl group having 1 to 12 carbon atoms. The alkyl group may be linear or branched. Moreover, C, and the -C _{I 2} alkoxy, an alkoxy group ranging from 1 or et 12 carbon atoms. The alkoxy group may be linear or branched. Ariruokishi group has a carbon number of usually 6 to about 60, specifically, phenoxy group, C, -C ₁₂ alkoxy phenoxyethanol group, C, -C ₁₂ alkylphenoxy group, 1-naphthyl Okishi group and 2-Nafuchiruokishi group and the like, C, -C _I2 alkoxy phenoxyethanol group, alkylphenoxy group are preferable.

Arirushiriru group has a carbon number of usually 6 to about 60, Fuenirushiriru group, C, ~ C ₁₂ alkoxy phenylalanine silyl group, ₂ alkylphenyl silyl group, 1-naphthyl Rushiriru group, 2-Nafuchirushiriru group, Jimechirufu An enylsilyl group and the like are exemplified, and a C, to C, ₂ alkoxyphenylsilyl group and a C, to C, ₂ alkylphenylsilyl group are preferred.An arylamino group has usually about 6 to 60 carbon atoms, and a phenylamino group, Jifue Niruamino group, C, -C _I2 alkoxy phenylalanine § amino group, di (Ci Cu Arukokishifue sulfonyl) amino group, di (C, -C ₁₂ alkylphenyl) amino groups, 1-Nafuchiruamino group, 2- Nafuchiruamino group etc. are exemplified, C, -C _I2 alkylphenyl § amino group, di (C, -C _I2 alkylphenyl) amino group.

§ reel alkyl group has a carbon number of usually 7 to about 60, specifically, phenylene Lou C, -C, ₂ alkyl group, C, -C ₁₂ alkoxy phenylalanine - C, -C, ₂ alkyl Group, C, ~ C ^ alkylphenyl-^ ~ alkyl group, 1-naphthyl. , ～〇, ₂ alkyl group, 2 one Nafuchiru C, -C | like ₂ alkyl groups and the like, C, -C, ₂ Arukokishifue two Roux C, -C, ₂ alkyl group, C, -C, ₂ Arukirufue Preferred are C2-C, ₂ alkyl groups. The arylalkoxy group usually has about 7 to 60 carbon atoms. Specifically, phenyl One C, -C _{I 2} alkoxy group, ^ ~. Alkoxyphenyl-alkoxy group,. , ～〇 ₁₂ Arukirufeniru - Ji, ~ Ji ₁₂ Arukokishi group, 1-naphthyl - C, -C, ₂ alkoxy groups, 2-naphthyl - C, -C, such as ₂ alkoxy groups and the like, C, -C _{I 2} alkoxy Shifue alkenyl - C, -C ₁₂ alkoxy group, ^ ~. Alkylphenyl-dialkoxy groups are preferred.

What is the normal number of carbon atoms in an arylalkylsilyl group? Is about to 60, specifically, Hue alkenyl - C, -C, ₂ alkyl silyl group, C, ~ C, ₂ Arukokishifue two Roux C, -C, ₂ alkyl Rushiriru group, ～〇 _{| 2} Arukirufu enyl - C, -C ₁₂ alkylsilyl group, 1-naphthyl - ^ ～〇 ₁₂ alkylsilyl group, 2-naphthyl - ₂ alkylsilyl group, such as phenyl one ₂ alkyldimethylsilyl groups and the like, Ji, ~. ^ Alkoxyphenyl mono-C, -C, ₂ alkylsilyl groups, C, -C, _2- alkylphenyl-C, -C, ₂ alkylsilyl groups are preferred.

The § reel alkylamino group, the carbon number thereof is usually about 7 to 60, specifically, phenylene Lou C, -C ₁₂ alkylamino group, ~ Ji ^ § Turkey hydroxyphenyl over ^ ~ Ji alkylamino group , ^ ~ Ji § Le kills phenyl over-Ji ^ Arukiruamino groups, di (C, ～〇, ₂ § Turkey hydroxyphenyl - ○ ₁ ～〇 ₁₂ Arukiru) amino group, di (C, ~ C ₁₂ alkyl phenylene Lou C, -C ₁₂ alkyl) amino groups, 1-naphthyl -! C C alkylamino group, such as 2-Nafuchiru ₂ alkylamino groups and the like, etc. are exemplified, C, ~ C _{l 2} Arukirufue two Roux C, -C ₁₂ alkylamino group, di (〇, ～〇 ₁₂ alkylphenyl - C, -C _{I 2} alkyl) amino group.

The monovalent heterocyclic group usually has about 4 to 60 carbon atoms.Specifically, a phenyl group, a C, to C ₁₂ alkyl phenyl group, a pyrrolyl group, a furyl group, a pyridyl group, a C, to C Examples thereof include an _{I 2} alkyl pyridyl group, and a phenyl group, a C, to C, ₂ alkyl phenyl group, a pyridyl group, and a C, to C, ₂ alkyl pyridyl group are preferable. On the other hand, the divalent aromatic amine group refers to an atomic group obtained by removing two hydrogen atoms from the aromatic ring of the aromatic amine. Examples of the divalent aromatic amine group include a group represented by the formula (2).

Here, Ar, Ar ₃ and Ar ₅ are each independently an arylene group or a divalent complex ring group. Ar ₂ and Ar ₄ are each independently an aryl group or a monovalent heterocyclic group. n shows the integer of 0-3. When n is 2 or more, a plurality of Ar ₄ and Ar ₅ may be the same or different.

A ri in the repeating unit represented by the formula _{(2), Ar 2, Ar} 3, Ar 4 and Ar ₅ represents an alkyl group, alkoxy group, alkylthio group, alkylsilyl group, alkyl Ruamino group, Ariru group, Ariruokishi Group, arylsilyl group, arylamino group, arylalkyl group, arylalkoxy group, arylalkylsilyl group, arylalkylamino group, arylalkenyl group, arylalkynyl group, phenylethenyl group, alkylphenylethenyl group, It may have a substituent such as an alkoxyphenylethenyl group.

 Alkyl group, alkoxy group, alkylthio group, alkylsilyl group, alkylamino group

The definitions of aryl, aryloxy, arylsilyl, arylamino, arylalkyl, arylalkoxy, arylalkylsilyl and arylalkylamino groups, specific examples of which are those in R above The definition is the same as the specific example.

The aryl alkenyl group usually has about 8 to 60 carbon atoms. Specifically, phenyl—C _{2 to} C, ₂ alkenyl group, Ci to C, ₂ alkoxyphenyl—C _{2 to} C, ₂ Aruke two group, Ji, ~ Ji Arukirufeniru - ~ Arukeniru group, 1 one-naphthyl - C ₂ -C, ₂ alkenyl groups, 2-naphthyl - such as C ₂ -C ₁₂ alkenyl groups and the like, C, -C ₁₂ § Rukokishifueniru - C ₂ ~C, ₂ alkenyl groups, C, -C ₁₂ alkylphenyl - C ₂ -C ₁₂ alkenyl groups are preferred.

 The aryl alkynyl group usually has about 8 to 60 carbon atoms.

-C ₂ - C ₁₂ alkynyl group, C, -C, ₂ Arukokishifue two Roux C, -C, ₂ alkynyl group, ^ ~. Alkylphenyl - C ₂ - C ₁₂ alkynyl group, 1-Nafuchiru C ₂ ~ C, ₂ Al Kiniru group, 2-Nafuchiru C ₂ -C, such as ₂ alkynyl group and the like, ^ ~ Ji alkoxy Shifueniru - C ₂ - C, ₂ alkynyl group, C, ~C, ₂ Arukirufue two Lou C ₂ -C, ₂ alkynyl group are preferred. Specific examples of the repeating unit represented by the above formula (2) include the following.

Here, R is independently a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an alkylsilyl group, an alkylamino group, an aryl group, an aryloxy group, an arylsilyl group, an arylamino group, an arylalkyl group, or an arylalkoxy group. Groups, arylalkylsilyl groups, arylalkylamino groups, monovalent heterocyclic groups and cyano groups. In the above figure, one group has a plurality of Rs, which may be the same or different, or may be linked to each other to form a ring.

 The copolymer of the present invention has two or more types of repeating units selected from the group consisting of an arylene group, a divalent heterocyclic group, and a divalent aromatic amine group. The repeating unit may be selected from two or more of any one of an arylene group, a divalent heterocyclic group and a divalent aromatic amine group. Appropriate groups may be combined from the group consisting of a divalent heterocyclic group and a divalent aromatic amine group to form two or more types of repeating units.

Among the copolymers of the present invention, those containing a repeating unit represented by the formula (1) are preferable. Further, it is also preferable that both include the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2). Examples of the copolymer containing a repeating unit represented by the formula (1) include a copolymer composed of one kind of a group represented by the formula (1) and one kind of an arylene group as a repeating unit, Co-polymer consisting of two types of groups represented by formula (1) and two types of arylene groups Copolymer consisting of one kind of group represented by formula (1) and one kind of divalent heterocyclic group as a repeating unit, and one kind of group represented by formula (1) as a repeating unit A copolymer consisting of a divalent heterocyclic group of the formula: consisting of one kind of the group represented by the formula (1) as a repeating unit, one kind of a divalent arylene group, and one kind of a divalent heterocyclic group Copolymer, copolymer composed of two kinds of groups represented by formula (1) as repeating units, and copolymer composed of two kinds of groups represented by formula (1) and one kind of arylene group as repeating units Examples of the repeating unit include a copolymer comprising two types of groups represented by the formula (1) and one type of divalent heterocyclic group. From the viewpoint of solubility, one type of repeating unit may be used. A polymer comprising a group represented by the formula (1) and one kind of arylene group, A copolymer consisting of one kind of the group represented by the formula (1) and one kind of the divalent heterocyclic group, and a copolymer consisting of two kinds of the groups represented by the formula (1) as a repeating unit, A copolymer comprising two types of groups represented by formula (1) as a repeating unit is more preferable.

As a copolymer containing both the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), one kind of the group represented by the formula (1) and one kind of the formula (2) A copolymer consisting of a group represented by the formula (1), a copolymer consisting of one kind of the group represented by the formula (1) and two kinds of the groups represented by the formula (2) as the repeating unit, and one kind of the formula ( A copolymer comprising a group represented by formula (1), one kind of group represented by formula (2), and one kind of divalent heterocyclic group, and two kinds of groups represented by formula (1) as repeating units And one kind of a group represented by the formula (2), a repeating unit represented by one kind of the group represented by the formula (1) and one kind of a divalent arylene group, and one kind of the formula (2 A) a copolymer comprising a group represented by formula (1), two types of repeating units represented by formula (1) and a type represented by formula (2). A copolymer consisting of one group represented by the formula (1) and one kind of a divalent arylene group as a repeating unit, and a copolymer consisting of two kinds of the groups represented by the formula (2) However, from the viewpoint of polymerization stiffness, a copolymer consisting of one kind of the group represented by the formula (1) and one kind of the group represented by the formula (2) as a repeating unit, A copolymer consisting of two kinds of groups represented by the formula (1) and two kinds of the groups represented by the formula (2), and two kinds of the groups represented by the formula (1) and one kind of the formula (2) as repeating units A copolymer comprising a group represented by the formula (1), a group represented by the formula (2), and a divalent heterocyclic group as a repeating unit. As the repeating unit, a copolymer comprising one kind of the group represented by the formula (1) and one kind of the divalent arylene group and one kind of the group represented by the formula (2) is preferable. As a repeating unit, a copolymer comprising one kind of the group represented by the formula (1) and one kind of the group represented by the formula (2), and one kind of the repeating unit represented by the formula (1) and two kinds A copolymer comprising a group represented by the formula (2) is more preferable.

 Further, in the copolymer, the total amount of the repeating units represented by an arylene group and / or a divalent heterocyclic group and / or a divalent aromatic amine group is the total number of repeating units of the copolymer. It is preferably at least 80 mol% of the unit, more preferably at least 90 mol%, most preferably substantially at least 100 mol%. Further, it is more preferable that the repeating unit represented by the formula (1) accounts for 50 mol% or more of all the repeating units of the copolymer.

 In the copolymer of the present invention, if the proportion of one type of repeating unit is too large, the characteristics of the copolymer are similar to those of a polymer having a single repeating unit, and for example, the solubility in a solvent for coating may be improved. The resolution may decrease. Therefore, in the copolymer, one kind of the repeating unit is preferably 90 mol% or less of all the repeating units of the copolymer.

 As a polymerization method for obtaining the copolymer of the present invention, for example, a method of performing polymerization by a Suzuki coupling reaction using a monomer corresponding to a repeating unit by polymerization (Chemical Review

(Chem. Rev.), Vol. 95, p. 2457 (1995)), Polymerization by Grignard reaction (Kyoritsu Shuppan, Functional Polymer Series, Volume 2, Synthesis and Reaction of Polymer ( 2), 432-3), a method of polymerizing by the Yamamoto polymerization method (Progressive Polymer-Sci., Vol. 17, 1153-1205, 1992), FeCl a method of polymerization with an oxidizer such as _3, electrochemical oxidation polymerization to that method (Maruzen, experimental chemistry 4th edition, vol. 28, 339- 340 pp), and the like. As a method for obtaining the copolymer of the present invention, polymerization may be carried out under polymerization conditions capable of obtaining a molecular weight distribution satisfying the conditions of the present invention, or, after polymerization, if necessary, reprecipitation purification, chromatography, or the like. Alternatively, a method of performing separation by a field flow fractionation method to obtain a polymer having a molecular weight range satisfying the above-mentioned conditions, or a method of using these methods in combination is exemplified. Examples of operations such as reprecipitation purification after polymerization include, for example, a method in which a poor solvent is dropped into a good solvent solution of a polymer, or a method in which a good solvent solution is dropped into a poor solvent. Conditions such as the combination of a good solvent and a poor solvent, and the amount ratio are selected according to the type of polymer.Examples of a good solvent include toluene, xylene, chloroform, dichloromethane, trichloroethane, and tetrahydrofuran. And toluene and xylene are preferred. Examples of the poor solvent include methanol, ethanol, 2-propanol and acetone, and methanol and ethanol are preferred. The polymer concentration of the good solvent solution is preferably 0.5% by weight or less, and the volume ratio of the good solvent to the poor solvent is less than the volume of the good solvent, from the viewpoint of removing the low molecular weight components as much as possible. Preferably, the volume of the solvent is small. The method of dropping is preferably a method of dropping a poor solvent into a good solvent solution of a polymer. It is preferable to use a decantation method or a centrifugal method for collecting the precipitate. Since the recovered precipitate may contain a solvent, it is preferable that the precipitate is dissolved in a good solvent again and the reprecipitation operation is repeated. The good solvent and the poor solvent used in the reprecipitation operation to be performed again are as described above, but from the viewpoint of increasing the recovery rate of the polymer, a method in which the good solvent solution is dropped into the poor solvent or added at once is preferable.

Chromatography used for the post-polymerization chromatographic treatment includes normal phase chromatography using silica or alumina as a carrier; reverse phase chromatography using alkyl silica as a carrier; SEC; supercritical fluid chromatography. SEC is preferred from the viewpoint of controlling the molecular weight of Mn and the molecular weight in terms of polystyrene of 1 × 10 ⁵ or less. In the method using SEC, Mn is in the range of 2 × 10 ^{5 to} 7 × 10 ⁵ , and the proportion of molecules having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene is 5.0% by weight or less. , the fraction in the presence of high molecular weight among the copolymers, existing fractionation of copolymers with a molecular weight of the intermediate, and molecular weight in terms of polystyrene 1 X 1 0 ⁵ or less of the copolymer is present By fractionating the fractions separately and mixing them as appropriate, a polymer having a controlled molecular weight distribution can be obtained. The copolymer fractionated by SEC is purified by removing the solvent, but is preferably further purified by a method such as reprecipitation in order to avoid contamination of the solvent with impurities.

The field flow fractionation method separates a mixture based on the difference in the translational diffusion coefficient of the molecules in the solution, but the translational diffusion coefficient of the molecules in the solution is related to the molecular weight. Therefore, it can be used as a method for obtaining a copolymer having a controlled molecular weight distribution according to the present invention. In order to obtain a copolymer having a controlled molecular weight distribution using the field flow fractionation method, specifically, in the field flow fractionation method, a component having a large translational diffusion coefficient of a molecule in a solution, that is, Since low molecular weight components elute first, it is preferable to collect components that flow out in the middle of the day, excluding components that flow out late, so that Mn falls within the above range, except for components that flow out quickly. .

 Next, the polymer composition of the present invention will be described.

 The polymer composition of the present invention is characterized by containing at least 50% by weight of the copolymer of the present invention. The polymer composition of the present invention may contain two or more types of the copolymers contained in the present invention. When two or more types of copolymers included in the present invention are included, the combination of the copolymers and the composition are improved in properties such as solubility in a solvent, glass transition temperature, lifetime, and brightness when fabricated into an element. There is no particular limitation as long as it causes it.

 Examples of the component other than the copolymer of the present invention contained in the polymer composition of the present invention include a polymer compound. As the polymer compound, specifically, JP-A-2001-247861, JP-A-2001- Polymer compounds described in, for example, Japanese Patent No. 507511, JP-A-2001-504533, JP-A-2001-278958, JP-A-2001-261796, JP-A-2001-226469, and Patent No. 3161058 are exemplified. Examples of the polymer compound include polyfluorene-based compounds, polyfluorene-based copolymers, polyarylene-based compounds, polyarylene-based copolymers, polyarylenevinylene-based compounds, polyarylenevinylene-based copolymers, and polystilbene-based compounds. , Polystilbene copolymers, polystilbene vinylene compounds, polystilbene vinylene copolymers, polypyridinediyl compounds, polypyridinediyl copolymers, alkoxypolythiophene compounds, alkoxypolythiophene copolymers Polymers, and the like.Polyfluorene-based copolymers, polyarylene-based copolymers, polyarylenevinylene-based copolymers, polystilbene-based copolymers, and polystilbene-vinylene copolymers are exemplified. It is not limited to.

 The polymer LED of the present invention has a light-emitting layer between electrodes consisting of an anode and a cathode, and the light-emitting layer contains the copolymer or polymer composition of the present invention.

In the polymer LED of the present invention, at least one electrode and the light emitting layer are adjacent to the electrode. Polymer light-emitting device provided with a layer containing a conductive polymer, and a polymer light-emitting device provided with an insulating layer having an average thickness of 2 nm or less between at least one electrode and the light-emitting layer adjacent to the electrode. In addition, the polymer LED of the present invention includes a polymer LED having an electron transport layer between a cathode and a light-emitting layer, and a polymer LED having a hole transport layer between an anode and a light-emitting layer. Examples of the LED include a polymer LED in which an electron transport layer is provided between a cathode and a light emitting layer, and a hole transport layer is provided between an anode and a light emitting layer.

 Specific examples of the structure of the polymer LED of the present invention include the following structures a) to d).

a) Anode / luminescent layer Z cathode

b) Anode / Hole transport layer / Emitting layer / Cathode

c) Anode Emission layer Electron transport layer Z cathode

d) Anode / hole transport layer Emitting layer Z 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 transport layer is a layer having a function of transporting holes, and the electron transport layer is a layer having a function of transporting electrons. It is. Note that the electron transport layer and the hole transport layer are collectively called a charge transport layer.

 Two or more light emitting layers, hole transport layers, and electron transport layers may be used independently.

 Among the charge transport layers provided adjacent to the electrodes, those having the function of improving the charge injection efficiency from the electrodes and having the effect of lowering the driving voltage of the device are particularly suitable for the charge injection layers (hole injection layers). , Electron injection layer).

 In addition, the above-described charge injection layer or an insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode to improve adhesion to the electrode and improve charge injection from the electrode. A thin insulating layer may be inserted at the interface between the charge transport layer and the light emitting layer for improving the performance and preventing mixing. The order and number of layers to be laminated 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 injection layer adjacent to an anode. To Provided polymer LED.

 For example, the following structures e) to p) are specifically mentioned.

e) Anode / charge injection layer Emitting layer / cathode

f) Anode Light emitting layer / charge injection layer Z cathode

g) Anode Charge injection layer Light emitting layer / charge injection layer Cathode

h) Anode Z charge injection layer Z hole transport layer / light emitting layer / cathode

i) Anode / hole transport layer Z light emitting layer Charge injection layer anode

j) Anode Charge injection layer / Hole transport layer / Emitting layer / Charge injection layer / Cathode

k) Anode Charge injection layer Z light-emitting layer Electron transport layer / cathode

1) Anode Emission layer / Electron transport layer Z charge injection layer / Cathode

m) Anode Charge injection layer Z emission layer Electron transport layer Charge injection layer / cathode

n) Anode Z charge injection layer Hole transport layer Z light emitting layer / electron transport layer / cathode

o) anode hole transport layer / emission layer electron transport layer / charge injection layer / cathode

 P) Anode / Charge injection layer Hole transport layer / Emitting layer Electron transport layer Z charge injection layer Cathode

 Specific examples of the charge injection layer include a layer containing a conductive polymer, a layer provided between the anode and the hole transport layer, and an intermediate layer between the anode material and the hole transport material contained in the hole transport layer. A layer containing a material having an ionization potential of a value, provided between the cathode and the electron transport layer, and containing a material having an electron affinity of an intermediate value between the cathode material and the electron transport material contained in the electron transport layer. A layer is exemplified.

When the charge injection layer is a layer containing an electric conductive polymer, the electric conductivity of the conducting polymer is preferably 1 0- ⁵ S / cm or more and 10 ³ or less, the leakage current between light emitting pixels to smaller, more preferably at least 10 ² or less ^{10- 5 SZcm, 10- 5 S /} cm or more 1 0 ¹ or less is more preferred.

When the charge injection layer is a layer containing an electric conductive polymer, the electric conductivity of the conducting polymer, 1 0 ⁵ 10 ³ is preferably not more than S / cm or more SZcm, leak current between light emitting pixels for the smaller is more preferably 10 5 SZcm least 10 ² SZcm below 10- ⁵ 3 Ji 111 or more and 10 ¹ S / cm or less is more preferred.

Normally in order to the electric conductivity of the conducting polymer 10- ⁵ S / cm or more and 10 ³ or less, The conductive polymer is doped with an appropriate amount of ions.

 The type of ions to be doped is anion for the hole injection layer and cation for the electron injection layer. Examples of anions include polystyrenesulfonate, alkylbenzenesulfonate, camphorsulfonate, and the like.Examples of cations include lithium, sodium, potassium, and tetrabutylammonium. Is exemplified.

 The thickness of the charge injection layer is, for example, 1 ηπ! 100100 nm, and 211111 to 5011111 are preferred.

 The material used for the charge injection layer may be appropriately selected in relation to the electrode and the material of the adjacent layer.Polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylenevinylene and its derivatives, Conductive polymers such as polychenylenevinylene and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polymers having an aromatic amine structure in the main chain or side chain, metal phthalocyanine (such as copper phthalocyanine), Carbon is exemplified.

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

 Specifically, for example, the following c! ) To ab).

q) Anode / insulating layer with a thickness of 2 nm or less Light emitting layer Cathode

 r) Anode Light emitting layer Z Insulating layer with a thickness of 2 nm or less Cathode

 s) Anode Insulation layer with a thickness of 2 nm or less Emitting layer Insulation layer with a thickness of 2 nm or less t) Anode Insulating layer with a thickness of 2 nm or less Z Hole transport layer Emission layer / cathode

u) Anode / Hole transport layer / Emitting layer Insulating layer with thickness less than 2 nm Cathode

V) Anode Insulation layer with a thickness of 2 nm or less Hole transport layer Emission layer / Insulation layer with a thickness of 2 nm or less Z w) Anode / Insulation layer with a thickness of 2 nm or less Emission layer / Electron transport layer Z cathode x) Anode / light-emitting layer Z electron transport layer Insulation layer / cathode with thickness of 2 nm or less

y) Anode Z Insulating layer with thickness less than 2 nm Emitting layer Z Electron transport layer Insulating layer with thickness less than 2 nm, z) Insulating layer with anode thickness less than 2 nm / Hole transporting layer Emitting layer / Electron transporting layer Z cathode aa) Anode Z Hole transport layer Emitting layer Electron transport layer / Insulating layer with thickness of 2 nm or less Z cathode ab) Anode Z Insulating layer with thickness of 2 nm or less Hole transport layer / Emitting layer / Electron transport layer / Insulating layer / cathode with thickness of 2 nm or less

 The light-emitting layer contains the copolymer or polymer composition of the present invention, but a light-emitting material other than the above-mentioned copolymer may be mixed and used in the light-emitting layer. Further, in the polymer LED of the present invention, a light-emitting layer containing a light-emitting material other than the above-described polymer fluorescent substance may be laminated with a light-emitting layer containing the above-mentioned copolymer.

 As the luminescent material, known materials can be used. Examples of low molecular compounds include naphthalene derivatives, anthracene or derivatives thereof, perylene or derivatives thereof, polymethine-based, xanthene-based, coumarin-based, and cyanine-based pigments, metal complexes of 8-hydroxyquinoline or its derivatives, Aromatic amine, tetraphenylcyclopentadiene or a derivative thereof, or tetraphenylbutadiene or a derivative thereof can be used. Specifically, known materials such as those described in, for example, JP-A-57-51781 and JP-A-59-194393 can be used.

 There is no limitation on the method of forming the light emitting layer, and for example, a method of forming a film from a solution is exemplified.

 Spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire-bar coating, dip coating, spray coating, screen printing, etc. , Flexographic printing, offset printing, inkjet printing, and other coating methods. Examples of the solvent used for film formation from a solution include toluene, xylene, chloroform, and tetrahydrofuran.

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 m, preferably 2 nn! ~ 500 nm, more preferably 5 nrr! ~ 200 nm.

 When the polymer LED of the present invention has a hole transport layer, the hole transport material used may be polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, or a polysiloxane having an aromatic amine in a side chain or a main chain. Derivatives, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, polyaniline or derivatives thereof, polythiophenes or derivatives thereof, polypyrrolyl or derivatives thereof, poly (P-phenylenepinylene) or derivatives thereof, or Examples thereof include poly (2,5-chenylenevinylene) or a derivative thereof.

 Specifically, as the hole transport material, JP-A-63-70257, JP-A-63-175860, JP-A-2-135359, JP-A-2-135361, JP-A-209988 And Japanese Patent Application Laid-Open Nos. 3-37992 and 3-152184.

 Among them, as a hole transporting material used for the hole transporting layer, polypinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, or a polyarene derivative is used. Polymeric hole transport materials such as diphosphorus or a derivative thereof, polythiophene or a derivative thereof, poly (p-phenylenevinylene) or a derivative thereof, or poly (2,5-chenylenevinylene) or a derivative thereof are preferable. More preferred are polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain or a main chain. In the case of a low-molecular-weight hole transporting material, it is preferable to use it by dispersing it in a polymer binder.

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

 Examples of the polysilane or a derivative thereof include compounds described in Chemical Review (Chem. Rev.), Vol. 89, p. 1359 (1989), and British Patent GB 2300196. Although the synthesis methods described above can be used as the synthesis method, the Kipping method is particularly preferably used.

Since the siloxane skeleton structure has little hole-transporting property, those having the above-described structure of the low-molecular-weight hole-transporting material in the side chain or the main chain are preferably used as the polysiloxane or its derivative. Can be Particularly, those having an aromatic amine having a hole transporting property in a side chain or a main chain are exemplified. There is no limitation on the method of forming the hole transport layer. For the low molecular weight hole transport material, a method of forming a film from a mixed solution with a polymer binder is exemplified. For the polymer hole transport material, a method by film formation 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. Examples of the solvent include chlorinated solvents such as chloroform, methylene chloride, and dichloroethane; ether solvents such as tetrahydrofuran; aromatic hydrocarbon solvents such as toluene and xylene; and ketones such as acetone and methyl ethyl ketone. Examples of the solvent include ester solvents such as ethyl acetate, butyl acetate and ethyl cellosolve acetate.

 The method of film formation from a solution includes spin coating from a solution, casting, microgravure coating, gravure coating, vacuum coating, roll coating, wire coating, dip coating, spray coating. , Screen printing, flexographic printing, offset printing, inkjet printing, etc. can be used. The polymer binder to be mixed is preferably one that does not extremely inhibit charge transport, Those having low absorption are preferably used. Examples of the polymer binder include polyacrylonitrile, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

 The optimal value of the thickness of the hole transport layer differs depending on the material used, and the thickness may be selected so that the driving voltage and the luminous efficiency are appropriate values. If the thickness is too large, the driving voltage of the device becomes high, which is not preferable. Therefore, the thickness of the hole transport layer is, for example, 1 nm to 1 tm, preferably 2 nm to 500 nm, and more preferably 5 ηπ! ~ 200 nm.

When the polymer LED of the present invention has an electron transporting layer, known electron transporting materials can be used, such as oxadiazole derivative, anthraquinodimethane or its derivative, benzoquinone or its derivative, naphthoquinone or its derivative. 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, polyquinoxaline or a derivative thereof, polyfluorene or a derivative thereof, and the like.

 Specifically, JP-A-63-72057, JP-A-63-175860, JP-A-2-135359, JP-A-213 Examples are those described in JP-A-53-611, JP-A-2-209988, JP-A-3-3792, JP-A-3-152984, etc. Is performed.

 Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinone or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinolines or derivatives thereof, polyquinoxalines or derivatives thereof, and polyfluorenes or derivatives thereof are preferable. — (4-biphenylyl) — 5— (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferred.

 There is no particular limitation on the method for forming the electron transport layer, but for low-molecular-weight electron transport materials, a vacuum deposition method from a powder or a method by film formation from a solution or molten state is used. Alternatively, a method of forming a film from 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 dissolves the electron transport material and / or the polymer binder. Examples of the solvent include chlorinated solvents such as chloroform, methylene chloride and dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, and ketones such as acetone and methyl ethyl ketone. Examples of the solvent include ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.

Spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire-bar coating, dip coating, spray coating It is possible to use a coating method such as a printing method, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method. As the polymer binder to be mixed, those that do not extremely inhibit charge transport are preferable, and those that do not strongly absorb visible light are suitably used. Examples of the polymer binder include poly (N-vinylcarbapool), polyaniline or a derivative thereof, polythiophene or a derivative thereof, poly (p-phenylenevinylene) or a derivative thereof, and poly (2,5-che). (Dilenvinylene) or a derivative thereof, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, or polysiloxane.

 The optimum value of the thickness of the electron transporting layer differs depending on the material used, and may be selected so that the driving voltage and the luminous efficiency are appropriate values, but at least a thickness that does not cause pinholes is necessary. Yes, too thick is not preferable because the driving voltage of the device becomes high. Therefore, the thickness of the electron transport layer is, for example, 1 nm to 1 im, and preferably 2 ηπ! 5500 nm, more preferably 5 nm 2200 nm.

 The substrate for forming the polymer LED of the present invention is not limited as long as it does not change when the electrodes are formed and the organic layer is formed, and examples thereof include glass, plastic, polymer films, and silicon substrates. . In the case of an opaque substrate, the opposite electrode is preferably transparent or translucent.

 Usually, it is preferable that at least one of the electrodes consisting of the anode and the cathode is transparent or translucent, and the anode side is transparent or translucent. As a material of the anode, a conductive metal oxide film, a translucent metal thin film, or the like is used. Specifically, a film made of a conductive glass made of indium oxide, zinc oxide, tin oxide, or a complex thereof, such as indium tin oxide (ITO), indium zinc zinc oxide, or the like ( NESA, 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. Further, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the anode.

The thickness of the anode can be appropriately selected in consideration of light transmittance and electric conductivity. For example, the thickness is from 10 nm to 10; am, and preferably from 20 nm to l jtim. Yes, even better Preferably it is 50 nm to 500 nm.

 In order to facilitate charge injection, a layer made of a phthalocyanine derivative, a conductive polymer, carbon, or the like, or an average film thickness made of a metal oxide, a metal fluoride, an organic insulating material, etc. A layer of nm or less may be provided.

 As the material of 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, Metals such as vanadium, zinc, yttrium, indium, cerium, samarium, single-ended pium, terbium, ytterbium, and alloys of two or more of them, or one or more of them, and gold, silver, and platinum An alloy with one or more of copper, manganese, titanium, cobalt, nigell, tungsten, and tin, graphite, or graphite intercalation compound 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, etc. . 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, but is, for example, 10 nm to 10 m, and is preferably It is 20 nm to 1 m, and more preferably 50 nm to 500 nm.

 As a method for producing the cathode, a vacuum evaporation method, a sputtering method, a lamination method in which a metal thin film is thermocompression-bonded, and the like are used. 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. After preparing the cathode, a protective layer for protecting the polymer LED may be attached. In order to use the polymer LED stably for a long period of 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 whose surface has been subjected to a low water permeability treatment, or the like can be used. A method of pasting and sealing with a daughter board is suitably used. If the space is maintained by using a spacer, it is easy to prevent the element from being damaged. If the space is filled with an inert gas such as nitrogen or argon, oxidation of the cathode can be prevented. Further, by installing a drying agent such as barium oxide in the space, the moisture adsorbed in the manufacturing process can be prevented. This makes it easier to suppress damage to the device. It is preferable to take one or more of these measures.

 The polymer light emitting device of the present invention can be used as a planar light source, a segment display, a dot matrix display, a backlight of a liquid crystal display, and the like.

 In order 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 of installing a mask provided with a patterned window on the surface of the planar light emitting element, and forming an extremely thick organic material layer of a non-light emitting portion substantially There is a method in which no light is emitted, a method in which one or both of the anode and the cathode are formed in a pattern. By forming a pattern by any of these methods and arranging several electrodes so that they can be independently turned on / off, a segment-type display element that can display numbers, letters, simple symbols, etc. 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 so as to be orthogonal to each other. A partial color display or a multi-color display can be achieved by a method in which a plurality of types of polymer phosphors having different emission colors are separately applied, or a method using a color filter or a fluorescence conversion filter. The dot matrix element can be passively driven, or may be actively driven in combination with TFT or the like. These display elements can be used as display devices such as computers, televisions, mobile terminals, mobile phones, power navigation systems, and video camera viewfinders.

Further, the planar light emitting element is a self-luminous thin type, 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 display device. Hereinafter, examples will be shown to explain the present invention in further detail, but the present invention is not limited to these. Number-average molecular weight in terms of polystyrene (Mn) The ratio of molecules having a molecular weight in terms of polystyrene of 1 × 10 ^{5 or} less and the weight-average molecular weight in terms of polystyrene are calculated by size exclusion chromatography (SEC) using tetrahydrofuran as a solvent. Determined by Synthesis example 1

Synthesis of Copolymer 1>

 1.3 g (0.0024mo 1) of 2,7-dibromo-1,9-dioctylfluorene, 0.27 g of 2,7-dibromo-9,9-diisopentylfluorene (0.0006mol) And 2. 2'-Bibiridyl 1. lg (0.007 Omo 1) were dissolved in 12 OmL of dehydrated tetrahydrofuran, and the system was purged with nitrogen by publishing with nitrogen. Under a nitrogen atmosphere, bis (1,5-cyclooctadiene) nickel (0) 1.8 g (0.0065 mol) was added to this solution, and the mixture was stirred at room temperature for 10 minutes, and then heated to 60. The reaction was performed for 3 hours. After the reaction, this reaction solution was cooled to room temperature (about 25 t), added dropwise to a mixed solution of 25% ammonia water 2 OmLZ methanol 10 OmLZ ion-exchanged water 20 OmL, stirred for 1 hour, and the deposited precipitate was filtered. After washing with methanol and drying under reduced pressure for 2 hours. Then, it was dissolved in toluene and filtered to remove insolubles. The solution was passed through a column filled with alumina. Next, 1N hydrochloric acid was added to this toluene solution and stirred for 1 hour. The aqueous layer was removed, and 3% aqueous ammonia was added to the organic layer. After stirring for 1 hour, the aqueous layer was removed. After adding water and stirring for 1 minute and removing the aqueous layer twice, methanol was added to the organic layer and the mixture was stirred for 1 hour. The deposited precipitate was filtered and washed with methanol. The deposited precipitate was filtered and dried under reduced pressure for 2 hours. Thereafter, the yield of the obtained copolymer was 0.64.

Mn of the copolymer 1, 2. 1 X 1 0 ^5, the weight average molecular weight in terms of polystyrene 5. 8 X 1 0 ^5, the proportion molecular weight in terms of polystyrene molecular of 1 X 1 0 ⁵ or less 5. It was 7% by weight. Synthesis example 2

<Synthesis of Copolymer 2> 2,7-dibromo-9,9-dioctylfluorene 26 g (0.048 mol), 2,7-dibutorone 9,9-diisopentylfluorene 5.6 g (0.012 mol) and After dissolving 22, 2'-bipyridyl (22 g, 0.14 mol) in dehydrated tetrahydrofuran (160 OmL), the system was purged with nitrogen by purging with nitrogen. Under a nitrogen atmosphere, bis (1,5-cyclooctadiene) nickel (0) 56 g (0.2 Omo 1) was added to this solution, and the temperature was raised to 6 Ot: and reacted for 8 hours. . After the reaction, the reaction solution is cooled to room temperature (at about 25), added dropwise to a mixed solution of 25% ammonia water (120 OmL), methanol (120 OmL) / ion-exchanged water (120 OmL), and stirred for 30 minutes. After washing with methanol, the resultant was dried under reduced pressure for 2 hours. Thereafter, the resultant was dissolved in 2600 mL of toluene, 260 OmL of 1N hydrochloric acid was added, and the mixture was stirred for 1 hour. The aqueous layer was removed, 260 OmL of 2% aqueous ammonia was added to the organic layer, and the mixture was stirred for 1 hour, and then the aqueous layer was removed. After adding 90 OmL of water and stirring for 1 minute and removing the aqueous layer twice, the organic layer was added dropwise to 290 OmL of methanol and stirred for 1 hour, and the deposited precipitate was filtered and washed with methanol. did. After drying under reduced pressure for 2 hours, the residue was dissolved in 230 OmL of toluene, purified through an alumina column (450 g of alumina), and the collected toluene solution was added dropwise to 450 OmL of methanol and stirred for 1 hour. The mixture was filtered and dried under reduced pressure for 2 hours. Thereafter, the yield of the obtained copolymer was 20 g.

Mn of the copolymer 2, 1. 9 X 1 0 ^5, the weight average molecular weight in terms of polystyrene 4. 3 X 10 ^5, the ratio of the molecular weight in terms of polystyrene occupied by 1 X 10 ⁵ or less molecule 10.1 wt %Met. Synthesis of Copolymer 3>

2,7-Jib mouth mo 9,9-Dioctylfluorene 20 g (0.036 mol), 2,7-Dibromo-1,9,9-diisopentylfluorene 4.2 g (0.009 Omo 1) and After dissolving 16.5 g (0.1 lmol) of 2,2'-bipyridyl in 120 OmL of dehydrated tetrahydrofuran, the system was purged with nitrogen by bubbling with nitrogen. Under a nitrogen atmosphere, 30 g (0. l lmol) of bis (1,5-cyclooctadiene) nickel (0) was added to this solution, and the mixture was stirred at room temperature for 10 minutes. 3 hours reaction I let it. After the reaction, the reaction solution was cooled to room temperature (about 25X :), added dropwise to a mixed solution of 25% ammonia water, 15 OmLZ methanol 70 OmL / ion-exchanged water 700 mL, and stirred for 1 hour. After washing with methanol, the resultant was dried under reduced pressure for 2 hours. Then, it was dissolved in toluene and filtered to remove insolubles. The solution was passed through a column filled with alumina. Next, 1N hydrochloric acid was added to the toluene solution and the mixture was stirred for 1 hour. The aqueous layer was removed, and 3% aqueous ammonia was added to the organic layer. After stirring for 1 hour, the aqueous layer was removed. Further, water was added and the mixture was stirred for 1 minute, and the operation of removing the aqueous layer was performed twice. Then, methanol was added to the organic layer and the mixture was stirred for 1 hour. The precipitated precipitate was filtered and washed with methanol. The deposited precipitate was filtered and dried under reduced pressure for 2 hours. Thereafter, the yield of the obtained copolymer was 5. O g.

The Mn of copolymer 3 is 2.9 × 10 ⁵ , the weight average molecular weight in terms of polystyrene is 5.1 × 10 ⁵ , and the proportion of molecules having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene occupies 4.4 weight. %Met. Example 1

 <Separation of specific components from copolymer 2>

 180 Omg of Copolymer 2 was dissolved in 50 OmL of toluene, and while keeping the temperature at 50, 20 Om1 of methanol was added dropwise over 2 hours. After stirring for 1 hour, the mixture was naturally cooled to room temperature. After the precipitated precipitate was left as it was and allowed to settle, the supernatant was removed by decantation, and the precipitate was dissolved in 100 mL of toluene. The toluene solution was added dropwise to 200 ml of methanol and stirred for 1 hour. The deposited precipitate was filtered and dried under reduced pressure for 2 hours to obtain a copolymer 2A. The yield of the obtained copolymer 2A was 207 mg.

The Mn of the copolymer 2 A is 4.3 X 10 ⁵ , the weight average molecular weight in terms of polystyrene is 6.5 X 10 ⁵ , and the ratio of molecules having a molecular weight in polystyrene of 1 X 10 ⁵ or less is 1.6 weight %Met.

Preparation and efficiency measurement of polymer LED containing 2A

 A 0.9% by weight toluene solution of the polymer 2A was prepared.

A glass substrate with a 150 nm thick ITO film deposited by sputtering is Ndoxythiophene) A film of 80 nm thickness was formed by spin coating using a solution of Z polystyrene sulfonic acid (Bayer, Baytron P), and dried on a hot plate at 200 for 10 minutes. Next, a film was formed at a rotation speed of 1600 rpm by spin coating using the toluene solution prepared above. The thickness was about 90 nm. Furthermore, after drying this under reduced pressure at 80 at 80 for 1 hour, about 4 11111, ₁ as a cathode buffer layer, about 5 nm of calcium as a cathode, and about 80 nm of aluminum were deposited to produce an EL element. . After the degree of vacuum reached below 1 X 10- ⁴ P a, vapor deposition of a metal was initiated. By applying a voltage to the obtained device, EL light emission having peaks at 428 nm and 452 nm was obtained. The device emitted 100 cdZm ² at about 5.5 V. The maximum luminous efficiency was 0.75 cd / A. Example 2

 <Separation of specific components from copolymer 1 by SEC>

 200.2 mg of Copolymer 1 was weighed and dissolved in 40 ml of toluene, and 200 1 of each was injected into a SEC column to separate a specific component of Copolymer 1. The SEC column is a PL gel mixed C column and PL gel mixed D column manufactured by Polymer Laboratories.

Chromatography was performed using LC-1 10 Avp manufactured by Shimadzu, and tetrahydrofuran was used as the mobile phase for SEC at 6 Ot :. Flow rate per minute 1.

The volume was adjusted to 0 ml and the eluate was collected at 30 second intervals. Of the fractions, the fractions from 9 minutes to 13 minutes after the injection were combined and the solvent was removed to obtain Copolymer 1A.

Mn of the copolymer 1A is 6.2 × 10 ⁵ , and the weight average molecular weight in terms of polystyrene is 8.

The proportion of molecules having a molecular weight of 0 × 10 ⁵ and a polystyrene equivalent of 1 × 10 ⁵ or less was 0.1% by weight.

 <Preparation and efficiency measurement of polymer LED containing copolymer 1A>

A device was produced in the same manner as in Example 1 except that copolymer 1A was used instead of copolymer 2A. During the film formation, the rotation speed of the spinco per night was 1800 rpm, and the film thickness was about 100 nm. By applying a voltage to the obtained device, EL light emission having peaks at 436 nm and 460 nm was obtained. The device emitted 100 cd / m ² at about 5.6 V. Also maximum The luminous efficiency was 0.30 cd / A. Example 3

 <Synthesis of Copolymer 3>

 2,7-Jib mouth mo 9,9-Dioctylfluorene 20 g (0.036 mol), 2,7-Dibromo-9,9-diisopentylfluorene 4.2 g (0.009 Omo 1) and After dissolving 16.5 g (0.1 lmol) of 2, 2′-pipyridyl in 120 OmL of dehydrated tetrahydrofuran, the inside of the system was purged with nitrogen by bubbling with nitrogen. Under a nitrogen atmosphere, 30 g (0.1 lmo 1) of bis (1,5-cyclooctadiene) nickel (0) was added to this solution, and the mixture was stirred at room temperature for 10 minutes, and then heated to 60. The reaction was performed for 3 hours. After the reaction, the reaction solution was cooled to room temperature (approximately 251C), added dropwise to a mixed solution of 25% aqueous ammonia 15 OmL / methanol 70 OmL / ion-exchanged water 700 mL, and stirred for 1 hour. After filtration, washing with methanol and drying under reduced pressure for 2 hours. Then, it was dissolved in toluene and filtered to remove insolubles, and the solution was passed through a column filled with alumina. Next, 1N hydrochloric acid was added to this toluene solution and the mixture was stirred for 1 hour. The aqueous layer was removed, and 3% aqueous ammonia was added to the organic layer. After stirring for 1 hour, the aqueous layer was removed. After adding water and stirring for 1 minute and removing the aqueous layer twice, methanol was added to the organic layer and the mixture was stirred for 1 hour. The precipitated precipitate was filtered and washed with methanol. The deposited precipitate was filtered and dried under reduced pressure for 2 hours. Thereafter, the yield of the obtained copolymer was 5. O g.

The Mn of the copolymer 3 was 2.9 × 10 ⁵ , and the proportion of molecules having a polystyrene equivalent molecular weight of 1 × 10 ⁵ or less was 4.4% by weight.

<Preparation and efficiency measurement of polymer LED containing copolymer 3>

A device was produced in the same manner as in Example 1, except that Copolymer 3 was used instead of Copolymer 2A. The concentration of the toluene solution at the time of film formation was 1.2% by weight, the number of revolutions per night of the spinco was 1200 rpm, and the film thickness was about 200 nm. By applying voltage to the obtained device, EL light emission having peaks at 448 nm and 524 nm was obtained. The device emitted 100 cd / m ² at about 6.4 V. The maximum luminous efficiency was 0.60 cd / A. Comparative Example 1

 <Preparation and efficiency measurement of polymer LED containing copolymer 2>

A device was produced in the same manner as in Example 1, except that Polymer 2 was used instead of Copolymer 2A. The concentration of the toluene solution at the time of film formation was 0.9% by weight, the number of revolutions per night of the spinco was 2000 rpm, and the film thickness was about 70 nm. By applying a voltage to the obtained device, EL light emission having peaks at 424 nm and 448 nm was obtained. This device showed light emission of about 6. 2VT100 c dZm ^2. The maximum luminous efficiency was 0.10 OdZA. Comparative Example 2

 <Preparation and efficiency measurement of polymer LED containing copolymer 1>

A device was produced in the same manner as in Example 1, except that Polymer 1 was used instead of Copolymer 2A. The concentration of the toluene solution at the time of film formation was 0.9% by weight, the number of revolutions per night of the spinco was 2000 rpm, and the film thickness was about 80 nm. By applying a voltage to the obtained device, EL light emission having peaks at 424 nm and 448 nm was obtained. The device emitted 100 cd / m ² at about 6.7 V. The maximum luminous efficiency was 0.1 lc dZA.

Table 1 summarizes the results of Mn, the percentage of molecules having a polystyrene-equivalent molecular weight of 1 × 10 ⁵ or less, and the maximum emission efficiency.

Mn Molecule in terms of polystyrene Maximum luminous efficiency Percentage of molecules (c dZA) with an amount of 1 × 10 ⁵ or less

 (% By weight)

Copolymer 2 A 4.3 X 10 ⁵ 1.0.6.75 (Example 1)

Copolymer 1 A 6.2 X 10 ⁵ 0.1 0.30 (Example 2)

Copolymer 3 2.9 X 10 ⁵ 4.4.4.60 (Example 3)

Copolymer 2 1.9 X 10 ⁵ 10.1 0.10 (Comparative Example 1)

Copolymer 1 2.1 X 10 ⁵ 5.7 0.10 (Comparative Example 2) Industrial applicability

 When the copolymer of the present invention is used as a light-emitting material for a light-emitting layer of a polymer LED, the polymer LED has high luminous efficiency. Therefore, the polymer LED can be preferably used for devices such as curved or flat light sources for backlighting or illumination of liquid crystal displays, segment type display elements, and dot matrix flat panel displays. Further, the copolymer of the present invention can be used as a dye for laser, a material for organic solar cells, an organic semiconductor for organic transistors, and a material for conductive thin films.

Claims

The scope of the claims

1. A copolymer having at least two types of repeating units selected from the group consisting of arylene groups, divalent heterocyclic groups, and divalent aromatic amine groups, wherein A copolymer having a molecular weight of 1 × 10 ⁵ or less in terms of polystyrene of 5.0% by weight or less and emitting fluorescence in a solid state.

 2. The copolymer according to claim 1, having two or more types of repeating units selected from the group consisting of an arylene group and a divalent heterocyclic group.

3. The copolymer according to claim 1, wherein the number average molecular weight in terms of polystyrene is 2 × 10 ⁵ 7 × 10 ⁵ .

 4. The copolymer according to claim 1, wherein at least one of the repeating units is a repeating unit represented by the following formula (1).

)

[Wherein, and R ₂ each independently represent a hydrogen atom, an alkyl group, an aryl group or a monovalent heterocyclic group. R ₃ and R ₄ are each independently an alkyl group, an alkoxy group, an alkylthio group, an alkylsilyl group, an alkylamino group, an aryl group, an aryloxy group, an arylsilyl group, an arylamino group, an arylalkyl group, an arylalkoxy group, or an aryloxy group. Represents a reelalkylsilyl group, an arylalkylamino group, a monovalent heterocyclic group or a cyano group. m and n each independently represent an integer of 03. When a plurality of R ₃ and R ₄ are present, they may be the same or different. Further, two or more of RR ₂ R ₃ and R ₄ may be connected to each other to form a ring.

5. The copolymer according to claim 4, wherein the repeating unit is at least two kinds selected from the repeating units represented by the above formula (1) and the following formula (2).

Wherein, Αι ^, A r ₃ and A r ₅ each independently represent a Ariren group or a divalent multi heterocyclic group, Ar ₂ and Ar _4, Ariru group, or monovalent heterocyclic each independently And t represents an integer of 0 to 3. When a plurality of Ar ₄ and Ar ₅ are present, they may be the same or different. ]

 6. The copolymer according to claim 4, wherein the repeating units are two types selected from the repeating units represented by the above formula (1).

 7. A polymer composition comprising the copolymer according to claim 1 in an amount of 50% by weight or more.

 8. A light-emitting layer is provided between an electrode comprising an anode and a cathode, and the light-emitting layer contains the copolymer according to any one of claims 1 to 6 or the polymer composition according to claim 7. A high molecular light emitting device characterized by the following.