JP2007302729A - Charge transport material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new charge transport material excellent in charge transport ability using a new type polymer having fluorene residues in side chains. <P>SOLUTION: The charge transport material includes a polymer having 30-100 mole% structural unit expressed by formula (wherein Ra and Rb express each an electron donating group bound to an aromatic ring Ar; A and B express each a structural unit able to express electroconductivity). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a charge transport material including a polymer having a fluorene residue in a side chain and a charge (hole) transport ability, and a novel polymer having a charge transport ability.

  It is known that some polymers having a fluorene residue in the side chain have a stacking helical structure and have a charge transporting ability depending on the π-conjugated electron characteristic of the fluorene residue (Patent Document 1).

  The polymer of patent document 1 is polyester, and it is supposed that a charge transfer complex having good stability is formed by using polyester.

  In addition, as a polymer having a fluorene residue in the side chain, it is excellent in solvent resistance useful as a thermally decomposable polymer having a dibenzofulvene skeleton (Patent Document 2), an optically active stationary phase for HPLC, and a polarization absorbing / emitting material. A polymer (Patent Document 3) is known.

  However, Patent Document 2 focuses only on optical activity, and Patent Document 3 focuses only on thermal decomposability, and does not suggest any electrical characteristics.

International Publication No. 03/095519 Pamphlet International Publication No. 03/102039 Pamphlet International Publication No. 03/095523 Pamphlet

  An object of the present invention is to provide a charge transport material using a new type of polymer having a fluorene residue in a side chain excellent in charge transport ability.

That is, the present invention provides the formula (1):
-(M)-(N)-
[Wherein, the structural unit M represents the formula (M):

（式中、Ｒ¹およびＲ²は同じかまたは異なり、いずれも水素原子または有機基；Ａｒは芳香環；ＲａおよびＲｂは同じかまたは異なり、いずれも芳香環Ａｒに結合している電子供与性基；ＡおよびＢは同じかまたは異なり、いずれも電気伝導性を発現し得る構造単位；Ｘは単結合、−（ＣＨ₂）_p−（ｐは正の整数）、−ＣＨ＝ＣＨ−、２価の芳香族基、ヘテロ原子またはヘテロ原子を含む有機基；ｍは０〜１０００の整数；ｎは０〜１０００の整数；ただし、ｍ＋ｎは１以上）で示される構造単位、
構造単位Ｎは構造単位Ｍを与える単量体と共重合可能な単量体に由来する構造単位、
かつ構造単位Ｍを３０〜１００モル％および構造単位Ｎを０〜７０モル％含む］で示される電荷輸送能を有するポリマーを含む電荷輸送材料に関する。

(Wherein R ¹ and R ² are the same or different and both are hydrogen atoms or organic groups; Ar is an aromatic ring; Ra and Rb are the same or different and both are bonded to the aromatic ring Ar. A group; A and B are the same or different, and both are structural units capable of expressing electrical conductivity; X is a single bond, — (CH ₂ ) _p — (p is a positive integer), —CH═CH—, 2 A structural unit represented by a valent aromatic group, a hetero atom or an organic group containing a hetero atom; m is an integer of 0 to 1000; n is an integer of 0 to 1000;
Structural unit N is a structural unit derived from a monomer copolymerizable with the monomer giving structural unit M,
And 30 to 100 mol% of structural unit M and 0 to 70 mol% of structural unit N].

At least one of the-(A) _m-and- (B) _n- is a moiety having a charge transporting ability, particularly an oligofuran group, a polyfuran group, an oligothiophene group, a polythiophene group, an oligopyrrole group, a polypyrrole group, an oligo An aromatic π-conjugated compound residue selected from the group consisting of a fluorene group, a polyfluorene group and a substituted derivative thereof is preferable from the viewpoint of high conductivity.

  At least one of the electron donating groups Ra and Rb is a hydrogen atom, an alkyl group, —OH (or a salt thereof), a mercapto group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic ring. A thio group, an amino group, an alkylamino group, an arylamino group or a heterocyclic amino group is preferable from the viewpoint of simplicity in production.

  The structural unit M is represented by the formula (M1):

（式中、Ｒ¹、Ｒ²、Ｒａ、Ｒｂ、Ａ、Ｂ、ｍおよびｎは式（Ｍ）と同じ；ｑおよびｒは同じかまたは異なり、いずれも１〜４の整数）で示されるフルオレン構造単位Ｍ１であるとき、製造上の簡便性の点で好ましい。

(Wherein R ¹ , R ² , Ra, Rb, A, B, m and n are the same as those in formula (M); q and r are the same or different and both are integers of 1 to 4). When it is the structural unit M1, it is preferable at the point of the simplicity on manufacture.

Formula (2):
-(M1)-(N)-
[Wherein, the structural unit M1 is represented by the formula (M1):

（式中、Ｒ¹、Ｒ²、Ｒａ、Ｒｂ、Ａ、Ｂ、ｍおよびｎは式（Ｍ）と同じ；ｑおよびｒは同じかまたは異なり、いずれも１〜４の整数）で示されるフルオレン構造単位Ｍ１；
構造単位Ｎは構造単位Ｍ１を与える単量体と共重合可能な単量体に由来する構造単位、
かつ構造単位Ｍ１を３０〜１００モル％および構造単位Ｎを０〜７０モル％含む］で示される電荷輸送能を有するポリマーは、文献未記載の新規ポリマーである。

(Wherein R ¹ , R ² , Ra, Rb, A, B, m and n are the same as those in formula (M); q and r are the same or different and both are integers of 1 to 4). Structural unit M1;
The structural unit N is a structural unit derived from a monomer copolymerizable with the monomer giving the structural unit M1,
And a polymer having a charge transporting ability represented by 30 to 100 mol% of structural unit M1 and 0 to 70 mol% of structural unit N is a novel polymer not described in any literature.

  According to the present invention, it is possible to provide a charge transport material having improved charge (hole) transport ability and improved solvent solubility.

The polymer used for the charge transport material of the present invention has the formula (1):
-(M)-(N)-(1)
[Wherein, the structural unit M represents the formula (M):

（式中、Ｒ¹およびＲ²は同じかまたは異なり、いずれも水素原子または有機基；Ａｒは芳香環；ＲａおよびＲｂは同じかまたは異なり、いずれも芳香環Ａｒに結合している電子供与性基；ＡおよびＢは同じかまたは異なり、いずれも電気伝導性を発現し得る構造単位；Ｘは単結合、−（ＣＨ₂）_p−（ｐは正の整数）、−ＣＨ＝ＣＨ−、２価の芳香族基、ヘテロ原子またはヘテロ原子を含む有機基；ｍは０〜１０００の整数；ｎは０〜１０００の整数；ただし、ｍ＋ｎは１以上）で示される構造単位、
構造単位Ｎは構造単位Ｍを与える単量体と共重合可能な単量体に由来する構造単位、
かつ構造単位Ｍを３０〜１００モル％および構造単位Ｎを０〜７０モル％含む］で示される電荷輸送能を有するポリマーである。

(Wherein R ¹ and R ² are the same or different and both are hydrogen atoms or organic groups; Ar is an aromatic ring; Ra and Rb are the same or different and both are bonded to the aromatic ring Ar. A group; A and B are the same or different, and both are structural units capable of expressing electrical conductivity; X is a single bond, — (CH ₂ ) _p — (p is a positive integer), —CH═CH—, 2 A structural unit represented by a valent aromatic group, a hetero atom or an organic group containing a hetero atom; m is an integer of 0 to 1000; n is an integer of 0 to 1000;
Structural unit N is a structural unit derived from a monomer copolymerizable with the monomer giving structural unit M,
And 30 to 100 mol% of the structural unit M and 0 to 70 mol% of the structural unit N are included].

In the formula (M) of the structural unit M, R ¹ and R ² are the same or different and both are hydrogen atoms or organic groups.

  As the organic group, for example, an alkyl group, an aromatic group, a cyano group, an ester group and the like are preferable from the viewpoint of ease of production and improvement of solvent solubility. In particular, an alkyl group is preferable in terms of improving solvent solubility. Alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, etc. Is preferred. Preferred is an alkyl group having 3 or more carbon atoms, and particularly preferred is an alkyl group having 6 or more carbon atoms.

  Ar is an aromatic ring, and may be an aromatic ring composed of only carbon atoms (carbon-based aromatic ring) or an aromatic ring containing hetero atoms as ring-constituting atoms (heterocyclic ring).

  Preferred examples of the carbon-based aromatic ring include aromatic rings composed of 4 to 14 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a tetracene ring, a pentacene ring, a pyrene ring, and a phenanthrene ring. In particular, a 6-membered ring is preferable because the compound is excellent in stability and easy synthesis. The two Ars may be different, but the same is preferable from the viewpoint of easy synthesis.

  Examples of the hetero ring aromatic ring include a pyridine ring, a bipyridine ring, a phenanthroline ring, a quinoline ring, an isoquinoline ring, a thiophene ring, a furan ring, and a pyrrole ring.

  Ra and Rb are the same or different and both are electron donating groups bonded to the aromatic ring Ar. The electron donating group may be an electron donating atom such as a hydrogen atom. In this case, a hydrogen atom is preferred from the viewpoint of stability of the compound and ease of production.

Ra and Rb may be an electron-donating nitrogen atom, oxygen atom, sulfur atom-containing atomic group, or organic groups Ra ¹ and Rb ¹ . In that case, each of Ra ¹ and Rb ¹ may be two or more. In that case, each of Ra ¹ and Rb ¹ may be the same or different.

Preferred examples of the electron donating groups Ra ¹ and Rb ¹ include an electron donating atomic group such as —OH (or a salt thereof), a mercapto group, and an amino group; an alkyl group, an alkoxy group, an aryloxy group, and a heterocyclic oxy group. And an electron donating organic group such as an alkylthio group, an arylthio group, a heterocyclic thio group, an alkylamino group, an arylamino group or a heterocyclic amino group, and particularly an alkyl group, —OH ( Or a salt thereof), a mercapto group, an alkoxy group, an aryloxy group, an amino group, an alkylamino group, or an arylamino group.

  As an alkyl group, a C1-C20 thing is preferable at the point which manufacture is easy.

  Specifically, for example, linear alkyl groups such as methyl, ethyl, n-octyl and n-dodecyl; branched alkyl groups such as i-propyl, tert-butyl and iso-decyl; cyclic alkyl groups such as cyclopentyl and cyclohexyl In particular, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group, and the like are preferable because of good solvent solubility.

  The salt of —OH is not particularly limited in the present invention, but may be a monovalent cation, preferably an alkali metal salt, more preferably a sodium salt or a potassium salt.

  As an alkoxy group, a C1-C20 thing is preferable at the point which manufacture is easy.

  Specifically, for example, methoxy group, ethoxy group, normal propyloxy group, isopropyloxy group, normal butyloxy group, tertiary butyloxy group, normal hexyloxy group, normal octyloxy group, 2-ethylhexyloxy group, 3, 5,5-trimethylhexyloxy group, normal decyloxy group, normal dodecyloxy group, cyclohexyloxy group, 3-pentyloxy group, benzyloxy group, allyloxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 2- Phenoxyethoxy group, neopentyloxy group, 2- (2,5-di-tertiary amylphenoxy) ethoxy group, 2-benzoyloxyethoxy group, methoxycarbonylmethyloxy group, methoxycarbonylethyloxy group, butoxycarboni An ethyloxy group, 2-isopropyloxyethyloxy group, and the like are mentioned. Particularly, since the solvent solubility is good, an alkoxy group having 1 to 16 carbon atoms is more preferable, and a methoxy group, an ethoxy group, a normal propyloxy group, Normal hexyloxy group, normal octyloxy group, 2-ethylhexyloxy group, 3,5,5-trimethylhexyloxy group, cyclohexyloxy group, 3-pentyloxy group, 2-methoxyethoxy group, neopentyloxy group are more preferable. .

  The aryloxy group is preferably an aryloxy group having a total carbon number of 6 to 20 because it may be substituted or unsubstituted and may be easily produced, and includes a phenoxy group, a 4-methylphenoxy group, 2- A methylphenoxy group or a 2-chlorophenoxy group is preferred.

  Among these, an aryloxy group having 6 to 8 carbon atoms is particularly preferable from the viewpoint of improving solvent solubility, and a phenoxy group and a 4-methylphenoxy group are particularly preferable.

  As the heterocyclic oxy group, a pyridyloxy group, a pyrimidyloxy group, an indolyloxy group, a benzothiazolyloxy group, a benzimidazolyloxy group, a furyloxy group, a thienyloxy group, a pyrazolyloxy group, because it is easy to produce. An imidazolyloxy group and the like are preferable. A pyridyloxy group and a pyrimidyloxy group are particularly preferred because of good solvent solubility.

  As the alkylthio group, those having 1 to 18 carbon atoms are preferable from the viewpoint of easy production.

  Specific examples include a methylthio group, an ethylthio group, a butylthio group, a hexylthio group, a heptylthio group, an octylthio group, a dodecylthio group, a tetradecylthio group, an octadecylthio group, and the like. A C1-C12 alkylthio group is good, and a butylthio group, a hexylthio group, a heptylthio group, and an octylthio group are preferable.

  As the arylthio group, a phenylthio group, a tolylthio group, a biphenylthio group, a naphthylthio group, a benzylthio group, a tritylthio group and the like are preferable from the viewpoint of easy production. In particular, a phenylthio group, a tolylthio group and the like are preferable because of good solvent solubility.

  As the heterocyclic thio group, a pyridylthio group, a pyrimidylthio group, an indolylthio group, a benzothiazolylthio group, a benzimidazolylthio group, a furylthio group, a thienylthio group, a pyrazolylthio group, an imidazolylthio group, etc. Is preferred. A pyridylthio group and a pyrimidylthio group are particularly preferred because of good solvent solubility.

  As the alkylamino group, those having 1 to 44 carbon atoms are preferable from the viewpoint of easy production.

  Specific examples include a dialkylamino group and a cycloalkylamino group. The dialkylamino group includes a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, a dihexylamino group, or a carbon number of an alkyl group such as a dialkylamino group. The thing of 1-22 is good independently. Examples of the cycloalkylamino group include a cyclopropylmethylamino group, a cyclopentylmethylamino group, a cyclohexylmethylamino group, and a cycloheptylmethylamino group. Particularly, since the solvent solubility is good, the carbon number of the alkyl group is Dialkylamino groups that are independently 1-6 are preferred.

  As the arylamino group, a monoarylamino group having 1 to 10 carbon atoms and a diarylamino group containing an amino group in which two hydrogen atoms are substituted with an aryl group are preferable from the viewpoint of easy production.

  Specifically, examples of the monoarylamino group include anilino, N-phenyl-N-ethylamino, 1-indolinyl, and the like, and examples of the diarylamino group include N, N-diphenylamino group, N, N-didiyl. (Biphenylyl) amino group, N, N-di (terphenylyl) amino group, N-phenyl N-biphenylylamino group, N-phenyl N-terphenylylamino group, N-biphenylyl N-terphenylylamino group, N , N-dinaphthylamino group, N-phenyl N-naphthylamino group, N-biphenylyl N-naphthylamino group, N-terphenylyl N-naphthylamino group, N-methylphenyl-N-biphenylylamino group, N-methyl Phenyl-N-naphthylamino group, N-methylphenyl-N-phenylamino group, N, N-di (methylphenyl) E) amino group and the like, and particularly because of good solvent solubility, anilino, N-phenyl-N-ethylamino, N, N-diphenylamino group, N, N-di (biphenylyl) amino group, N N-di (terphenylyl) amino group and N-phenyl N-biphenylylamino group are preferred.

  The heterocyclic amino group is preferably a pyridylamino group or a benzotriazol-5-ylamino group from the viewpoint of easy production.

The electron donating groups Ra ¹ and Rb ¹ may be either one, but it is preferable to have both Ra ¹ and Rb ¹ from the viewpoint of easy production. The number of electron-donating groups Ra ¹ and Rb ¹ to be substituted varies depending on the number of carbon atoms constituting the aromatic ring Ar, the type of electron-donating group, the number of carbon atoms of the electron-donating group, etc. It is preferable that the number of bonded hydrogen atoms is 1 to 8, more preferably 1 to 6, from the viewpoint of easy production. For example, when the aromatic ring Ar is a 6-membered ring consisting only of carbon atoms, Ra and Rb may all be hydrogen atoms. In addition, the total number of the electron donating groups Ra ¹ and Rb ¹ is preferably ¹ to 4, and more preferably 1 to 2 from the viewpoint of easy production.

A feature of the present invention is that not only the characteristics of the charge transport ability are improved by the characteristics of the π-conjugated electrons (Ra and Rb) in the fluorene residue of the stacking helical structure, but also-(A) _m-and- (B) _n- It is also possible to impart charge transporting ability with at least one of the above.

  An aromatic π-conjugated compound residue is preferred as the site having charge transporting ability, among which oligofuran group, polyfuran group, oligothiophene group, polythiophene group, oligopyrrole group, polypyrrole group, oligofluorene group, polyfluorene group and Those substituted derivatives can be preferably exemplified.

  Preferred examples of the substituted derivative of the aromatic π-conjugated compound include those substituted with various groups represented by Ra and Rb. In this case, Ra or Rb substituted on the aromatic ring Ar and the substituent of the aromatic π-conjugated compound may be the same or different.

  Further, in the aromatic π-conjugated compound residue, the aromatic π-conjugated compound constituting the same may be the same or different.

Oligo- or polyfuran groups and substituted derivatives thereof include polymerization of furan rings or derivatives thereof in which either the 3-position, 4-position or both of the furan ring may be substituted with an electron-donating group Ra ¹ or Rb ^1. It may be a formed polymer or oligomer, and may be an oligomer or polymer in which the 5-position of the furan ring may be substituted with Ra ¹ or Rb ¹ at the polymerization terminal.

As the electron donating groups Ra ¹ and Rb ¹ as substituents, those described above can be exemplified together with preferred examples.

Oligo- or polythiophene groups and substituted derivatives thereof include polymerization of a thiophene ring or a derivative thereof in which either the 3-position, the 4-position or both of the thiophene ring may be substituted with an electron-donating group Ra ¹ or Rb ^1. The polymer or oligomer formed may be an oligomer or polymer that may be substituted with Ra ¹ or Rb ¹ at the 5-position of the thiophene ring at the polymerization terminal.

As the electron donating groups Ra ¹ and Rb ¹ as substituents, those described above can be exemplified together with preferred examples.

Oligo- or polypyrrole groups and substituted derivatives thereof include polymerization of a pyrrole ring or a derivative thereof in which either the 3-position, the 4-position or both of the pyrrole ring may be substituted with an electron-donating group Ra ¹ or Rb ^1. It may be a formed polymer or oligomer, and may be an oligomer or polymer in which the 5-position of the pyrrole ring may be substituted with Ra ¹ or Rb ¹ at the polymerization terminal.

As the electron donating groups Ra ¹ and Rb ¹ as substituents, those described above can be exemplified together with preferred examples.

Examples of oligo or polyfluorene groups and substituted derivatives thereof include fluorene rings or derivatives thereof in which either the 9-position, 9'-position or both of the fluorene ring may be substituted with an electron-donating group Ra ¹ or Rb ¹ . It is a polymer or oligomer formed by polymerization, and it may be an oligomer or polymer that may be substituted with Ra ¹ or Rb ¹ in the 2 or 7 position (otherwise hydrogen atom) of the fluorene ring at the polymerization end. Good.

As the electron donating groups Ra ¹ and Rb ¹ as substituents, those described above can be exemplified together with preferred examples.

  m is an integer of 0 to 1000. Preferably 1 to 600, particularly 1 to 100 is preferable. n is an integer of 0 to 1000. Preferably 1 to 600, particularly 1 to 100 is preferable. m and n may be the same or different, but m + n is 1 or more.

X is a single bond, — (CH ₂ ) _p — (p is a positive integer, preferably 1 to 4), —CH═CH—, a divalent hydrocarbon aromatic group, a heteroatom or a heteroatom 2 Valent organic group. Examples of the divalent hydrocarbon aromatic group include benzene, naphthalene, anthracene, phenanthrene and the like. Examples of the heteroatom include O, S, N, Se, and the like. Examples of the divalent organic group containing a heteroatom include —NR— (where R is an alkyl group, aryl group, heterocycle), —O—, Examples include -S- and -Se-.

  Among these, a single bond, —O—, and —S— are preferable from the viewpoint of easy production.

  Of the structural unit M represented by the formula (M), Ar is a 6-membered ring of carbon atoms and X is a single bond (M1):

（式中、Ｒ¹、Ｒ²、Ｒａ、Ｒｂ、Ａ、Ｂ、ｍおよびｎは式（Ｍ）と同じ；ｑおよびｒは同じかまたは異なり、いずれも１〜４の整数）で示されるフルオレン構造単位Ｍ１であることが、製造が容易である点で好ましい。

(Wherein R ¹ , R ² , Ra, Rb, A, B, m and n are the same as those in formula (M); q and r are the same or different and both are integers of 1 to 4). The structural unit M1 is preferable in terms of easy production.

  Specific examples of the structural unit M include the following, but are not limited thereto.

などがあげられる。 formula:

Etc.

  The structural unit N is a structural unit derived from an ethylenically unsaturated group-containing monomer (however, the structural unit M is excluded) and is an arbitrary unit.

Specifically, the following structural units can be exemplified.
(1) Olefin unit Specific examples include ethylene, propylene, 1-butene, 2-butene, 1-hexene, 1-octene, 1-pentene, 1-tetradecene, norbornene, cyclopentene, styrene and the like.
(2) Fluorine-containing olefin unit Specific examples include vinylidene fluoride, hexafluoropropene, tetrafluoroethylene, perfluorovinyl ether, chlorotrifluoroethylene, trifluoroethylene, and the like.
(3) (Meth) acrylate unit Specifically, for example, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, tetrahydrofurfuryl methacrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl methacrylate, 2- Examples thereof include hydroxyethyl acrylate, ethoxyethyl methacrylate, ethoxyethyl acrylate, N-isopropylacrylamide, N-isopropylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, and hydroxypropyl acrylate.
(4) Fluorine-containing (meth) acrylate unit Specifically, for example, the general formula CH ₂ = CRCOO (CH ₂ ) _n (CF ₂ ) _m X (X is H or F; n is an integer of 0 to 2; An integer of 1 to 8; R may be H, CH ₃ , F or CF ₃ ).

Among these, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, CH ₂ = CRCOO (CH ₂ ) _n (CF ₂ ) _m X, and the like are preferable from the viewpoint of improving solvent solubility.

  The polymer represented by the formula (1) may be composed of the structural unit M alone (100 mol%). In the case of constituting a copolymer with the structural unit N, the structural unit M needs to be 30 mol% or more in order to obtain a good electron transport ability. The proportion of the structural unit M is preferably 40 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more.

Formula (2):
-(M1)-(N)-(2)
(Wherein the structural units M1 and N are the same as those in the formula (M1); the structural unit M1 is contained in 30 to 100 mol% and the structural unit N is contained in 0 to 70 mol%). A good polymer.

  The polymers represented by the formulas (1) and (2) can be produced, for example, by the following method.

（式中、Ｒ¹、Ａｒ、Ｒａ、Ｒｂ、Ａ、Ｂ、Ｘ、ｍおよびｎは式（Ｍ）と同じ）で示される単量体（ｍ）を単独重合するか、単量体（ｍ）と共重合可能な単量体（ｎ）とを共重合することにより製造することができる。 Formula (m):

(Wherein R ¹ , Ar, Ra, Rb, A, B, X, m and n are the same as those in the formula (M)), the monomer (m) is homopolymerized or the monomer (m ) And a copolymerizable monomer (n).

  As the polymerization method, a radical polymerization method, an anionic polymerization method, a cationic polymerization method and the like can be adopted, and the polymerization conditions may be selected from known conditions.

  Alternatively, Ra, Rb, A, B may be introduced into the (co) polymer obtained by (co) polymerizing monomers not having Ra, Rb, A, B.

  The monomer (m) can be produced by introducing Ra, Rb, A, and B into the iodine or brominated Ar site by reaction.

  As a number average molecular weight of the polymer shown by Formula (1) and Formula (2), it is 350-100000, Furthermore, 700-5000 are preferable. Moreover, as glass transition temperature Tg, it is 50 degreeC or more, Preferably it is 100 degreeC or more. If Tg is too low, structural changes tend to occur at the use temperature.

  The charge transport material of the present invention can be dissolved or dispersed in a solvent, and a coating method such as spin coating, dip coating, spray coating, roll coating, gravure coating, ink jet or other known coating methods can be used. As a method of forming efficiently, a spin coat method, a gravure coat method, etc. are preferable, and a spin coat method is particularly preferable, and it can be produced by applying to a substrate or a layer by these methods.

  Since the charge transport material of the present invention can stably transport charges (holes), it can be used for optical, electro-optic or electronic devices. For example, organic field effect transistors (FETs) for liquid crystal displays, optical films, and thin film transistor liquid crystal displays. Or OFET), and integrated circuit devices such as RFID tags, electroluminescent devices in flat panel displays, and photovoltaic and sensor devices.

  Next, the present invention will be specifically described based on examples and the like, but the present invention is not limited to such examples.

The characteristic values used in this specification are measured by the following method.
( ¹ H-NMR measurement (500 MHz))
Model name: JEOL ECP500 (manufactured by JEOL Ltd.)
Measuring solvent: deuterated chloroform (concentration 4.00 × 10 ⁻³ M)
(SEC (GPC) measurement (linear polystyrene conversion))
Model name: Hitachi L-7100 (pump) manufactured by Hitachi, Ltd., L-7420 UV detector (254 nm), L-7490 RI detector Column names: G6000HHr and G3000HHr manufactured by Tosoh Corporation
Developing solvent: THF
(Absorption spectrum measurement)
Model name: JASCO V-550 (manufactured by JASCO Corporation)
Solvent: THF
(Fluorescence spectrum measurement)
Model name: JASCO FP-777 (manufactured by JASCO Corporation)
Excitation light: 365 nm
Solvent: THF

Synthesis Example 1 [Synthesis of Monomer (BT-DBF)]

(1) Synthesis of 2- (2,2′-bithiophen-5-yl) -9-fluorenone (2- (2,2′-bithiophen-5-yl) -9-fluorenone) 200 ml flame-dried and nitrogen-substituted In a three-necked flask, 10.26 g (61.8 mmol) of 2,2′-bithiophene was placed. 80 ml of the solvent THF and 9.33 ml (61.8 mmol) of TMEDA were added thereto, and the mixture was cooled to 0 ° C. in an ice bath. Next, 39.36 ml (61.8 mmol) of 1.57 M n-BuLi / hexane was added, and the mixture was returned to room temperature and stirred for 2 hours (this is referred to as reaction liquid 1-1). Zinc chloride (12.11 g, 74.16 mmol) was placed in a separately prepared three-necked flask equipped with a 300 ml reflux tube, dried in a vacuum while spraying with a heat gun. After returning to nitrogen, 50 ml of THF was added. Thereafter, the reaction solution 1-1 was slowly added. The mixture was stirred at reflux for 1 hour and cooled to room temperature (non-uniform orange color; this was designated as reaction liquid 1-2). In a 500 ml three-necked flask purged with nitrogen and replaced with nitrogen, 8.0 g (10.9 mmol) of 2-bromofluorenone and 46.2 mg (0.040 mmol) of Pd (PPh ₃ ) ₄ were placed. THF 0.5ml was put here, and the reaction liquid 1-2 was added at room temperature. After heating for 12 hours under reflux, the reaction was stopped and the insoluble part was suction filtered. The soluble part was washed with saturated brine, and then the solvent was distilled off to obtain an orange powder. The obtained powder was washed with water, methanol and hexane. Column chromatography was performed with chloroform to obtain 5.64 g (yield 53.0%) of a yellow solid.

This was analyzed by ¹ H-NMR and confirmed to be 2- (2,2′-bithiophen-5-yl) -9-fluorenone.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.90 (m, 2H), 7.82 (m, 2H), 7.63 (m, 3H), 7.48 (d, 1H), 7.42 (d, 1H) , 7.38 (d, 1H), 7.33 (d, 1H), 7.12 (dd, 1H).

(2) of 2- (2,2′-bithiophen-5-yl) -9-methyl-9-fluorenol (2- (2,2′-bithiophen-5-yl) -9-methyl-9-fluorenol) Synthesis 6.30 g (18.3 mmol) of 2- (2,2′-bithiophen-5-yl) -9-fluorenone was placed in a 2 L three-necked flask subjected to flame drying and nitrogen substitution. After evacuating again, it was returned to nitrogen. 790 ml of THF was added and cooled to 0 ° C. with an ice bath. 30.5 ml (91.5 mmol) of CH ₃ MgBr was added and stirred at 0 ° C. for 4 hours. Methanol and 1N HCl aqueous solution were added little by little to stop the reaction. Extraction with diethyl ether, washing with saturated brine, and drying with magnesium sulfate gave a yellow powder residue before purification. The obtained residue was purified by column chromatography (chloroform) to obtain 6.4 g of an orange solid (yield 99.7%).

This was analyzed by ¹ H-NMR and confirmed to be 2- (2,2′-bithiophen-5-yl) -9-methyl-9-fluorenol.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.88 (s, 1H), 7.75 (m, 2H), 7.69 (dd, 1H), 7.59 (d, 1H), 7.45 (dd, 1H) , 7.34 (m, 4H), 7.12 (m, 1H).

(3) Synthesis of 2- (2,2′-bithiophen-5-yl) dibenzofulvene (BT-DBF) 2 in a 100 ml two-necked flask -(2,2'-Bithiophen-5-yl) -9-methyl-9-fluorenol (1.00 g, 2.77 mmol) was added, and the atmosphere was changed to nitrogen. Nitrogen bubbled benzene 20 ml and chloroform 20 ml were put here. The mixture was heated in an oil bath (60 ° C.), and 0.264 g (1.39 mmol) of p-toluenesulfonic acid hydrate (p-TsOH) was added. The reaction was stopped by stirring at reflux for 5 minutes. After washing with saturated brine and drying over magnesium sulfate, the solvent was distilled off to obtain 0.93 g of a yellow powder (yield 97.6%).

This was analyzed by ¹ H-NMR and confirmed to be 2- (2,2′-bithiophen-5-yl) dibenzofulvene.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.95 (s, 1H), 7.75 (d, 1H), 7.70 (d, 2H), 7.64 (d, 1H), 7.27 (t, 1H) , 7.26 (m, 2H), 7.23 (m, 2H), 7.19 (d, 1H), 7.05 (m, 1H), 6.15 (d, 2H).

Example 1 [Production of poly (BT-DBF)]

A 10 ml ampoule tube was flame-dried and put under nitrogen, and then 1.92 ml of 0.076 M BT-DBF in THF was added. 0.27 ml of THF was added here. The ampoule was cooled at −78 ° C. for about 10 minutes, and 0.73 ml of 0.1 M n-BuLi prepared separately was added as an initiator. After 41.5 hours, about 0.1 ml of methanol was added to stop the reaction. After pouring into about 50 ml of methanol, solvent separation was performed with methanol and THF. When the molecular weight of the obtained polymer was analyzed by SEC (GPC) analysis, the number average molecular weight was 2.2 × 10 ³ . Also, by ¹ H-NMR analysis, the peak of the proton derived from the vinyl group that is the polymerization site (6.15 ppm) disappeared, and the peak of the proton at the polymerization end and the proton derived from the methylene chain (around 1 to 4 ppm) appeared. It was confirmed that poly (BT-DBF) was produced by the polymerization reaction (see FIG. 1).

Synthesis Example 2 [Synthesis of Monomer (EHBT-DBF)]

(1) Synthesis of 5- (2-ethylhexyl) -2,2'-bithiophene (2- (2-ethylhexyl) -2,2'-bithiophene) , 2′-bithiophene 7.55 g (45.4 mmol) was added. The solvent THF444ml was put here and DBU33.9ml (22.7 mmol) was added. The mixture was cooled to -70 ° C, 1.61 M n-BuLi / hexane (0.38 ml, 0.612 mmol) was added, and the mixture was stirred for 30 minutes while maintaining -70 ° C, and then returned to room temperature and stirred for 1 hour. The temperature was raised to −15 ° C., and 16.15 ml (90.8 mmol) of 1-bromo-2-ethylhexane was added. The mixture was immediately returned to room temperature and stirred for 18 hours. The reaction was stopped with ammonium chloride, washed with water and saturated brine, dried over magnesium sulfate, and evaporated. Purification by column chromatography (hexane: ethyl acetate = 100: 1) gave 6.33 g of a pale yellow oil (yield 50.1%).

This was analyzed by ¹ H-NMR and confirmed to be 5- (2-ethylhexyl) -2,2′-bithiophene.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.16 (d, 1H), 7.10 (d, 1H), 6.99 (m, 2H), 6.65 (d, 1H), 2.75 (d, 2H) , 1.40 (m, 9H), 0.85 (m, 6H).

(2) Synthesis of 5-tributylstannyl-5 ′-(2-ethylhexyl) -2,2′-bithiophene (5-tributylstannyl-5 ′-(2-ethylhexyl) -2,2′-bithiophene) 6.2 g (22.3 mmol) of 5- (2-ethylhexyl) -2,2′-bithiophene obtained in (1) above and 120 ml of THF were placed in a 300 ml two-necked flask purged with nitrogen. Next, 15.3 ml (24.5 mmol) of 1.60 M n-BuLi / hexane was added at 0 ° C. and stirred for 1 hour. 6.65 ml (24.5 mmol) of Bu ₃ SnCl was added and stirred at room temperature for 20 hours. The reaction was stopped with ammonium chloride, washed with a saturated aqueous solution of sodium chloride, dried over sodium sulfate, and evaporated to give 13.0 g of a brown oil (yield> 99%).

This was analyzed by ¹ H-NMR and confirmed to be 5-tributylstannyl-5 ′-(2-ethylhexyl) -2,2′-bithiophene.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.23 (d, 1H), 7.05 (d, 1H), 6.95 (d, 1H), 6.65 (d, 1H), 2.27 (d, 2H) , 1.40 (m, 9H), 0.90 (m, 6H).

(3) 2,7-bis (5'-ethylhexyl-5,2'-bithiophen-2-yl) -9-fluorenone (2,7-bis (5'-ethylhexyl-5,2'-bithiophen-2-) yl) -9-fluorenone) 5-tributylstannyl-5 ′-(2-ethylhexyl) -2 prepared in (2) above dissolved in dry CHCl 3 in a 200 ml two-necked flask with flame dry and nitrogen substitution , 2′-bithiophene 12.1 g (21.2 mmol) was added. The solvent was distilled off again under vacuum, and 75.5 ml of dry toluene was added under nitrogen (this is referred to as reaction solution 2-1). 2.39 g (7.07 mmol) of 2,7-dibromofluorenone and 4817 mg (0.707 mmol) of Pd (PPh3) were placed in a 300 ml two-necked flask equipped with a reflux tube that was flame-dried and nitrogen-substituted. To this, 75.5 ml of toluene and reaction solution 2-1 were added. The mixture was stirred at 110 ° C. for 17 hours under reflux. The reaction was stopped with an aqueous ammonium chloride solution, washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, and evaporated to give 4.46 g of a red powder (yield 86.1%).

This was analyzed by ¹ H-NMR and confirmed to be 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-fluorenone.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ 7.89 (s, 2H), 7.68 (dd, 2H), 7.51 (d, 1H), 7.28 (d, 2H), 7.08 (d, 2H) , 7.03 (d, 2H), 6.69 (d, 2H), 2.75 (d, 4H), 1.60 (m, 2H), 1.36 (m, 16H), 0.91 (m, 12H).

(4) 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-methyl-9-fluorenol (2,7-Bis (5′-ethylhexyl-5,2′- Synthesis of bithiophen-2-yl) -9-metyl-9-fluorenol) 2,7-bis (5′-ethylhexyl-5) synthesized in (3) above in a flame-dried, nitrogen-substituted 500 ml three-necked flask 2.0 g (2.73 mmol) of 2′-bithiophen-2-yl) -9-fluorenone was added. After evacuation again, 333 ml of THF returned to nitrogen was added and cooled to 0 ° C. in an ice bath. A 4.5M solution of 3.3M CH ₃ MgBr / diethyl ether (13.7 mmol) was added, and the mixture was stirred at 0 ° C. for 4 hours. Methanol and HCl were added little by little to stop the reaction. The mixture was extracted with diethyl ether, washed with water and saturated brine, and dried over magnesium sulfate. Solvent fractionation was performed with methanol and hexane to obtain 1.79 g of an orange solid (yield 98.4%).

This was analyzed by ¹ H-NMR and confirmed to be 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-methyl-9-fluorenol.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ 7.80 (s, 2H), 7.61 (m, 4H), 7.28 (d, 2H), 7.10 (d, 2H), 7.03 (d, 2H) , 6.69 (d, 2H), 2.75 (d, 4H), 1.21 (m, 18H), 0.91 (m, 12H).

(5) 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) dibenzofulvene (2,7-Bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) Synthesis of dibenzofluvene) (EHBT-DBF) 2,7-bis (5'-ethylhexyl-5,2'-bithiophen-2-yl) -9-methyl- synthesized in (4) above in a 5 ml two-necked flask 9-Fluorenol 11.6 mg (0.0155 mmol) was added and placed under nitrogen. Nitrogen bubbled 3 ml of benzene and 3 ml of chloroform were added here. The mixture was heated in an oil bath at 60 ° C. for about 5 minutes, and 1.47 mg (0.00775 mmol) of p-toluenesulfonic acid hydrate was quickly added. After stirring at reflux for 5 hours, the reaction was immediately cooled in an ice bath to stop the reaction. The extract was washed with distilled water, dried over sodium sulfate, and evaporated to give 13.1 mg of yellow powder (yield> 99%).

This was analyzed by ¹ H-NMR and confirmed to be 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) dibenzofulvene.
¹ H-NMR (500 MH _Z , CDCl ₃ , ppm) δ7.93 (s, 2H), 7.67 (d, 2H), 7.63 (d, 2H), 7.28 (d, 2H), 7.11 (d, 2H) , 7.03 (d, 2H), 6.69 (d, 2H), 6.20 (s, 2H), 2.75 (d, 4H), 1.68 (m, 2H), 1.32 (m, 16H), 0.91 (m, 24H).

Example 2 [Production of poly (EHBT-DBF)]
2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) synthesized in (5) of Synthesis Example 2 of 0.0684M after a 10 ml ampule tube was subjected to frame drying and a nitrogen atmosphere. ) 0.60 ml of dibenzofulvene (EHBT-DBF) solution was added. To this was added 0.0158 ml of THF. The ampoule was cooled at −78 ° C. for about 10 minutes, and 0.205 ml of 1.59 M n-BuLi was added. After 68 hours, 0.1 ml of methanol was added to stop the reaction. Then, the mixture was poured into 30 ml of methanol, and solvent separation was performed with methanol and hexane. When the molecular weight of the obtained polymer was analyzed by SEC (GPC) analysis, the number average molecular weight was 1.33 × 10 ⁴ . Also, by ¹ H-NMR analysis, the peak of the proton derived from the vinyl group (6.20 ppm), which is the polymerization site, disappears, and the peak of the proton at the polymerization end and the proton derived from the methylene chain (around 0.5 to 3 ppm) appears. Then, it was confirmed that poly (EHBT-DBF) was produced by the polymerization reaction (see FIG. 2).

Example 3 [Structural analysis of poly (EHBT-DBF)]
The poly (EHBT-DBF) produced in Example 2 was dissolved in THF to a concentration of 1.99 × 10 ⁻⁵ M. Then, the solution was introduced into a quartz cell having an optical path length of 1 cm, and an absorption spectrum was measured to obtain a spectrum shown in FIG. 3 (solid line).

The absorption spectrum of poly (EHBT-DBF) shown in FIG. 3 includes 2,7-bis (5′-ethylhexyl), a monomer unit model obtained by measuring the absorption spectrum by the same method (concentration 1.68 × 10 ⁻⁵ M). A clear light-colored effect was observed compared to -5,2'-bithiophen-2-yl) -9-methyl-9-fluorenol (synthesized in (4) of Synthesis Example 2; dashed line).

Poly (EHBT-DBF) produced in Example 2 was dissolved in THF to a concentration of 1.99 × 10 ⁻⁶ M. Subsequently, the solution was introduced into a quartz cell having an optical path length of 1 cm, and a fluorescence spectrum was measured using excitation light of 365 nm to obtain a spectrum shown in FIG. 4 (solid line).

The monomer unit model 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-, whose fluorescence spectrum was measured in the same manner (concentration 1.35 × 10 ⁻⁶ M). Methyl-9-fluorenol (synthesized in (4) of Synthesis Example 2; dashed line) showed monomer emission centered at 400 to 450 nm, whereas poly (EHBT-DBF) centered around 500 nm. Excimer emission was shown.

In the ¹ H-NMR spectrum of poly (EHBT-DBF) produced in Example 2, the aromatic ring of the monomer 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) dibenzofulvene It was confirmed that the peak (see FIG. 2) showing the proton of the aromatic ring of poly (EHBT-DBF) was shifted in a high magnetic field with respect to the peak showing the proton of (7.93 ppm to 6.69 ppm).

  The above results indicate that poly (EHBT-DBF) has a π-stack structure between aromatic rings that easily cause charge transport.

  Similar results were observed for the poly (BT-DBF) produced in Example 1.

^{1 is} a ¹ H-NMR spectrum chart of poly (BT-DBF). ^{1 is} a ¹ H-NMR spectrum chart of poly (EHBT-DBF). 4 is an absorption spectrum chart of 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-methyl-9-fluorenol and poly (EHBT-DBF) measured in Example 3. FIG. 4 is a fluorescence spectrum chart of 2,7-bis (5′-ethylhexyl-5,2′-bithiophen-2-yl) -9-methyl-9-fluorenol and poly (EHBT-DBF) measured in Example 3. FIG.

Claims (10)

Formula (1):
-(M)-(N)-
[Wherein, the structural unit M represents the formula (M):

(Wherein R ¹ and R ² are the same or different and both are hydrogen atoms or organic groups; Ar is an aromatic ring; Ra and Rb are the same or different and both are bonded to the aromatic ring Ar. A group; A and B are the same or different, and both are structural units capable of expressing electrical conductivity; X is a single bond, — (CH ₂ ) _p — (p is a positive integer), —CH═CH—, 2 A structural unit represented by a valent aromatic group, a hetero atom or an organic group containing a hetero atom; m is an integer of 0 to 1000; n is an integer of 0 to 1000;
Structural unit N is a structural unit derived from a monomer copolymerizable with the monomer giving structural unit M,
And 30 to 100 mol% of structural units M and 0 to 70 mol% of structural units N]. The charge transport material according to claim 1, wherein at least one _of- (A) _m-and- (B) _n- is a site having charge transport ability. And at least one of the-(A) _m- and-(B) _n- is an oligofuran group, a polyfuran group, an oligothiophene group, a polythiophene group, an oligopyrrole group, a polypyrrole group, an oligofluorene group, a polyfluorene group, and their 3. The charge transport material according to claim 1, wherein the charge transport material is an aromatic π-conjugated compound residue selected from the group consisting of substituted derivatives. The charge transport material according to claim 1, wherein Ra and Rb are hydrogen atoms. At least one of Ra and Rb is an alkyl group, —OH or a salt thereof, a mercapto group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, or an alkylamino group. The charge transport material according to claim 1, which is an arylamino group or a heterocyclic amino group. The structural unit M is represented by the formula (M1):

(Wherein R ¹ , R ² , Ra, Rb, A, B, m and n are the same as those in formula (M); q and r are the same or different and both are integers of 1 to 4). The charge transport material according to claim 1, which is a structural unit M1. Formula (2):
-(M1)-(N)-
[Wherein, the structural unit M1 is represented by the formula (M1):

(Wherein R ¹ , R ² , Ra, Rb, A, B, m and n are the same as those in formula (M); q and r are the same or different and both are integers of 1 to 4). Structural unit M1;
The structural unit N is a structural unit derived from a monomer copolymerizable with the monomer giving the structural unit M1,
And 30 to 100 mol% of structural unit M1 and 0 to 70 mol% of structural unit N]. The polymer according to claim 7, wherein at least one _of- (A) _{m- and-} (B) _n- is a moiety having a charge transporting ability. And at least one of the-(A) _m- and-(B) _n- is an oligofuran group, a polyfuran group, an oligothiophene group, a polythiophene group, an oligopyrrole group, a polypyrrole group, an oligofluorene group, a polyfluorene group, and their The polymer according to claim 7 or 8, which is an aromatic π-conjugated compound residue selected from the group consisting of substituted derivatives. At least one of Ra and Rb is a hydrogen atom, an alkyl group, —OH or a salt thereof, a mercapto group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, The polymer according to any one of claims 7 to 9, which is an alkylamino group, an arylamino group, or a heterocyclic amino group.

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